Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Anxiety-like behavior induced by a combination of doxorubicin and cyclophosphamide may be mediated by serotonin (5-HT)2A receptor hyperactivity. The anxiolytic effects of fluoxetine may be inhibited by this combination. The present study examined the mechanisms underlying anxiety-like behavior induced by the combination doxorubicin and cyclophosphamide in rats. Anxiety-like behavior was induced during a light-dark test by the doxorubicin and cyclophosphamide treatment (once a week for 2 weeks). 5-HT2A receptor and 5-HT2A receptor-mediated extracellular signal-related kinase (ERK)1/2 levels were measured using Western blotting. 5-HT reuptake activity in fluoxetine-treated rats was also examined using microdialysis. ( ±)-1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane, a 5-HT2A receptor agonist, induced anxiety-like behavior. The fluoxetine treatment increased extracellular 5-HT concentrations in the hippocampus of vehicle- and doxorubicin and cyclophosphamide-treated rats. 5-HT transporter levels in the hippocampus were not affected by chemotherapy. The doxorubicin and cyclophosphamide treatment did not alter 5-HT2A receptor levels in the frontal cortex. However, chemotherapy increased 5-HT2A receptor-mediated ERK1/2 phosphorylation levels significantly more than the vehicle treatment. The present results suggest that anxiety-like behavior induced by the combination of doxorubicin and cyclophosphamide is mediated by 5-HT2A receptor hyperactivity without an increase in 5-HT2A receptor levels in rats.

DOI： 10.1007/s00213-021-05979-5

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Glutathione (GSH) is the most abundant intrinsic antioxidant in the central nervous system, and its substrate cysteine readily becomes the oxidized dimeric cystine. Since neurons lack a cystine transport system, neuronal GSH synthesis depends on cystine uptake via the cystine/glutamate exchange transporter (xCT), GSH synthesis, and release in/from surrounding astrocytes. Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), a detoxifying master transcription factor, is expressed mainly in astrocytes and activates the gene expression of various phase II drug-metabolizing enzymes or antioxidants including GSH-related molecules and metallothionein by binding to the antioxidant response element (ARE) of these genes. Accumulating evidence has shown the involvement of dysfunction of antioxidative molecules including GSH and its related molecules in the pathogenesis of Parkinson’s disease (PD) or parkinsonian models. Furthermore, we found several agents targeting GSH synthesis in the astrocytes that protect nigrostriatal dopaminergic neuronal loss in PD models. In this article, the neuroprotective effects of supplementation and enhancement of GSH and its related molecules in PD pathology are reviewed, along with introducing new experimental findings, especially targeting of the xCT-GSH synthetic system and Nrf2–ARE pathway in astrocytes.

DOI： 10.3390/ijms22168689

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Lactoferrin (Lf) is an iron-binding glycoprotein mainly found in exocrine secretions and the secondary granules of neutrophils. In the central nervous system (CNS), expression of the Lf protein has been reported in the lesions of some neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, as well as in the aged brain. Lf is primarily considered an iron chelator, protecting cells from potentially toxic iron or iron-requiring microorganisms. Other biological functions of Lf include immunomodulation and transcriptional regulation. However, the roles of Lf in the CNS have yet to be fully clarified. In this study, we raised an antiserum against mouse Lf and investigated the immunohistochemical localization of Lf-like immunoreactivity (Lf-LI) throughout the CNS of adult mice. Lf-LI was found in some neuronal populations throughout the CNS. Intense labeling was found in neurons in the olfactory systems, hypothalamic nuclei, entorhinal cortex, and a variety of brainstem nuclei. This study provides detailed information on the Lf-LI distribution in the CNS, and the findings should promote further understanding of both the physiological and pathological significance of Lf in the CNS.

DOI： 10.18926/AMO/61894

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：S. Karger AG  

<b><i>Background:</i></b> Cancer patients can suffer from psychological and cognitive disorders after chemotherapy, which influence quality of life. <b><i>Objective:</i></b> Oxidative stress may contribute to the psychological and cognitive disorders induced in rats by chemotherapy. In the present study, we examined the effects of N-acetylcysteine, an anti-oxidant, on anxiety-like behavior and cognitive impairment in rats treated with a combination of doxorubicin and cyclophosphamide. <b><i>Methods:</i></b> Rats were intraperitoneally injected with doxorubicin and cyclophosphamide once a week for 2 weeks. The light-dark test and the novel location recognition test were used to assess anxiety-like behavior and spatial cognition, respectively. The rats’ hippocampal levels of glutathione (GSH) and glutathione disulfide (GSSG) were measured using a GSSG/GSH quantification kit. <b><i>Results:</i></b> Combined treatment with doxorubicin and cyclophosphamide produced anxiety-like behavior and cognitive impairment in rats. N-acetylcysteine reversed the anxiety-like behavior and inhibition of novel location recognition induced by the combination treatment. Furthermore, the combination of doxorubicin and cyclophosphamide significantly reduced the rats’ hippocampal GSH/GSSG ratios. N-acetylcysteine reversed the reduction in the GSH/GSSG ratio seen in the doxorubicin and cyclophosphamide-treated rats. <b><i>Conclusion:</i></b> These results suggest that N-acetylcysteine inhibits doxorubicin and cyclophosphamide-induced anxiety-like behavior and cognitive impairment by reducing oxidative stress in the hippocampus.

DOI： 10.1159/000512117

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Parkinson’s disease (PD) is the second most common neurodegenerative disease. PD patients exhibit motor symptoms such as akinesia/bradykinesia, tremor, rigidity, and postural instability due to a loss of nigrostriatal dopaminergic neurons. Although the pathogenesis in sporadic PD remains unknown, there is a consensus on the involvement of non-neuronal cells in the progression of PD pathology. Astrocytes are the most numerous glial cells in the central nervous system. Normally, astrocytes protect neurons by releasing neurotrophic factors, producing antioxidants, and disposing of neuronal waste products. However, in pathological situations, astrocytes are known to produce inflammatory cytokines. In addition, various studies have reported that astrocyte dysfunction also leads to neurodegeneration in PD. In this article, we summarize the interaction of astrocytes and dopaminergic neurons, review the pathogenic role of astrocytes in PD, and discuss therapeutic strategies for the prevention of dopaminergic neurodegeneration. This review highlights neuron-astrocyte interaction as a target for the development of disease-modifying drugs for PD in the future.

DOI： 10.3390/cells9122623

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<title>Abstract</title>Mirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), is known to activate serotonin (5-HT) 1A receptor. Our recent study demonstrated that stimulation of astrocytic 5-HT1A receptors promoted astrocyte proliferation and upregulated antioxidative property in astrocytes to protect dopaminergic neurons against oxidative stress. Here, we evaluated the neuroprotective effects of mirtazapine against dopaminergic neurodegeneration in models of Parkinson’s disease (PD). Mirtazapine administration attenuated the loss of dopaminergic neurons in the substantia nigra and increased the expression of the antioxidative molecule metallothionein (MT) in the striatal astrocytes of 6-hydroxydopamine (6-OHDA)-injected parkinsonian mice via 5-HT1A receptors. Mirtazapine protected dopaminergic neurons against 6-OHDA-induced neurotoxicity in mesencephalic neuron and striatal astrocyte cocultures, but not in enriched neuronal cultures. Mirtazapine-treated neuron-conditioned medium (Mir-NCM) induced astrocyte proliferation and upregulated MT expression via 5-HT1A receptors on astrocytes. Furthermore, treatment with medium from Mir-NCM-treated astrocytes protected dopaminergic neurons against 6-OHDA neurotoxicity, and these effects were attenuated by treatment with a MT-1/2-specific antibody or 5-HT1A antagonist. Our study suggests that mirtazapine could be an effective disease-modifying drug for PD and highlights that astrocytic 5-HT1A receptors may be a novel target for the treatment of PD.

DOI： 10.1038/s41598-020-77652-4

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Other Link： http://www.nature.com/articles/s41598-020-77652-4

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Parkinson’s disease (PD) is a complex, multi-system, neurodegenerative disorder; PD patients exhibit motor symptoms (such as akinesia/bradykinesia, tremor, rigidity, and postural instability) due to a loss of nigrostriatal dopaminergic neurons, and non-motor symptoms such as hyposmia, autonomic disturbance, depression, and REM sleep behavior disorder (RBD), which precedes motor symptoms. Pathologically, α-synuclein deposition is observed in the central and peripheral nervous system of sporadic PD patients. To clarify the mechanism of neurodegeneration in PD and to develop treatment to slow or stop PD progression, there is a great need for experimental models which reproduce neurological features of PD. Animal models exposed to rotenone, a commonly used pesticide, have received most attention since Greenamyre and his colleagues reported that chronic exposure to rotenone could reproduce the anatomical, neurochemical, behavioral, and neuropathological features of PD. In addition, recent studies demonstrated that rotenone induced neuropathological change not only in the central nervous system but also in the peripheral nervous system in animals. In this article, we review rotenone models especially focused on reproducibility of central and peripheral multiple features of PD. This review also highlights utility of rotenone models for investigation of PD pathogenesis and development of disease-modifying drugs for PD in future.

DOI： 10.3390/neurosci1010001

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DOI： 10.1007/s11419-020-00527-w

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Crossed cerebellar diaschisis (CCD) is a state of hypoperfusion and hypometabolism in the contralesional cerebellar hemisphere caused by a supratentorial lesion, but its pathophysiology is not fully understood. We evaluated chronological changes in cerebellar blood flow (CbBF) and gene expressions in the cerebellum using a rat model of transient middle cerebral artery occlusion (MCAO). CbBF was analyzed at two and seven days after MCAO using single photon emission computed tomography (SPECT). DNA microarray analysis and western blotting of the cerebellar cortex were performed and apoptotic cells in the cerebellar cortex were stained. CbBF in the contralesional hemisphere was significantly decreased and this lateral imbalance recovered over one week. Gene set enrichment analysis revealed that a gene set for “oxidative phosphorylation” was significantly upregulated while fourteen other gene sets including “apoptosis”, “hypoxia” and “reactive oxygen species” showed a tendency toward upregulation in the contralesional cerebellum. MCAO upregulated the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the contralesional cerebellar cortex. The number of apoptotic cells increased in the molecular layer of the contralesional cerebellum. Focal cerebral ischemia in our rat MCAO model caused CCD along with enhanced expression of genes related to oxidative stress and apoptosis.

DOI： 10.3390/ijms21114137

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Epidemiological studies demonstrated that pesticide exposure, such as rotenone and paraquat, increases the risk of Parkinson’s disease (PD). Chronic systemic exposure to rotenone, a mitochondrial complex I inhibitor, could reproduce many features of PD. However, the adoption of the models is limiting because of variability in animal sensitivity and the inability of other investigators to consistently reproduce the PD neuropathology. In addition, most of rotenone models were produced in rats. Here, we tried to establish a high-reproducible rotenone model using C57BL/6J mice. The rotenone mouse model was produced by chronic systemic exposure to a low dose of rotenone (2.5 mg/kg/day) for 4 weeks by subcutaneous implantation of rotenone-filled osmotic mini pump. The rotenone-treated mice exhibited motor deficits assessed by open field, rotarod and cylinder test and gastrointestinal dysfunction. Rotenone treatment decreased the number of dopaminergic neuronal cells in the substantia nigra pars compacta (SNpc) and lesioned nerve terminal in the striatum. In addition, we observed significant reduction of cholinergic neurons in the dorsal motor nucleus of the vagus (DMV) and the intestinal myenteric plexus. Moreover, α-synuclein was accumulated in neuronal soma in the SNpc, DMV and intestinal myenteric plexus in rotenone-treated mice. These data suggest that the low-dose rotenone mouse model could reproduce behavioral and central and peripheral neurodegenerative features of PD and be a useful model for investigation of PD pathogenesis.

DOI： 10.3390/ijms21093254

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.fct.2020.111235

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DOI： 10.1016/j.neuint.2019.104608

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Pharmaceutical Society of Japan  

DOI： 10.1248/bpb.b19-00025

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Epidemiological studies have shown that coffee consumption decreases the risk of Parkinson’s disease (PD). Caffeic acid (CA) and chlorogenic acid (CGA) are coffee components that have antioxidative properties. Rotenone, a mitochondrial complex I inhibitor, has been used to develop parkinsonian models, because the toxin induces PD-like pathology. Here, we examined the neuroprotective effects of CA and CGA against the rotenone-induced degeneration of central dopaminergic and peripheral enteric neurons. Male C57BL/6J mice were chronically administered rotenone (2.5 mg/kg/day), subcutaneously for four weeks. The animals were orally administered CA or CGA daily for 1 week before rotenone exposure and during the four weeks of rotenone treatment. Administrations of CA or CGA prevented rotenone-induced neurodegeneration of both nigral dopaminergic and intestinal enteric neurons. CA and CGA upregulated the antioxidative molecules, metallothionein (MT)-1,2, in striatal astrocytes of rotenone-injected mice. Primary cultured mesencephalic or enteric cells were pretreated with CA or CGA for 24 h, and then further co-treated with a low dose of rotenone (1–5 nM) for 48 h. The neuroprotective effects and MT upregulation induced by CA and CGA in vivo were reproduced in cultured cells. Our data indicated that intake of coffee components, CA and CGA, enhanced the antioxidative properties of glial cells and prevents rotenone-induced neurodegeneration in both the brain and myenteric plexus.

DOI： 10.3390/cells8030221

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In previous studies, we found regional differences in the induction of antioxidative molecules in astrocytes against oxidative stress, postulating that region-specific features of astrocytes lead region-specific vulnerability of neurons. We examined region-specific astrocytic features against dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) as an oxidative stress using co-culture of mesencephalic neurons and mesencephalic or striatal astrocytes in the present study. The 6-OHDA-induced reduction of mesencephalic dopamine neurons was inhibited by co-culturing with astrocytes. The co-culture of midbrain neurons with striatal astrocytes was more resistant to 6-OHDA than that with mesencephalic astrocytes. Furthermore, glia conditioned medium from 6-OHDA-treated striatal astrocytes showed a greater protective effect on the 6-OHDA-induced neurotoxicity and oxidative stress than that from mesencephalic astrocytes. The cDNA microarray analysis showed that the number of altered genes in both mesencephalic and striatal astrocytes was fewer than that changed in either astrocyte. The 6-OHDA treatment, apparently up-regulated expressions of Nrf2 and some anti-oxidative or Nrf2-regulating phase II, III detoxifying molecules related to glutathione synthesis and export in the striatal astrocytes but not mesencephalic astrocytes. There is a profound regional difference of gene expression in astrocytes induced by 6-OHDA. These results suggest that protective features of astrocytes against oxidative stress are more prominent in striatal astrocytes, possibly by secreting humoral factors in striatal astrocytes.

DOI： 10.3390/ijms20030598

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

We examined whether combination treatment with doxorubicin and cyclophosphamide, a traditional chemotherapy for breast cancer, induced anxiety-like behavior in rats. Furthermore, we evaluated the role of the serotonin (5-HT)2A receptor subtype in the anxiety-like behavior induced by such chemotherapy. Rats were intraperitoneally injected with doxorubicin and cyclophosphamide once a week for 2 weeks. This caused the rats to display anxiety-like behavior during the light-dark test. In addition, we examined the rats' 5-HT2A receptor-mediated behavioral responses. Combination treatment with doxorubicin and cyclophosphamide significantly increased (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane, (a 5-HT2A receptor agonist)-induced wet-dog shake activity. This anxiety-like behavior was significantly inhibited by mirtazapine, a 5-HT2A receptor antagonist/5-HT1A receptor agonist, and tandospirone, a partial 5-HT1A receptor agonist, but not by fluoxetine, a selective serotonin reuptake inhibitor. The anxiety-like behavior induced by doxorubicin and cyclophosphamide combination treatment is mediated by hyperfunctioning of the 5-HT2A receptor. Thus, 5-HT2A receptor antagonists or 5-HT1A receptor agonists might be useful for treating chemotherapy-induced anxiety disorders.

DOI： 10.1016/j.jphs.2018.10.001

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© 2018, by Okayama University Medical School. We tried to clarify the applicability of a single prolonged stress (SPS) protocol as post-traumatic stress disorder (PTSD) model in mice. To investigate PTSD pathophysiology, we conducted hypothalamo-pituitary-adrenal (HPA) negative feedback testing at 1, 4, 8 and 12 weeks after the SPS by administrating a dexamethasone (DEX) suppression test. The SPS induced over-suppression of the HPA system by DEX treatment at 8 and 12 weeks. To investigate PTSD-like behavioral characteristics, we subjected mice to testing in a light/dark box (to assess anxiety), a Y-maze (working memory), a cliff avoidance (visual cognition), and an open field (locomotor activity) at 1, 4, 8 and 12 weeks after the SPS. In the light/dark box test, the SPS-applied mice spent significantly less time in the light box at 8 or 12 weeks. In the cliff avoidance test, the SPS-applied mice spent significantly less time in the open area at 1 week. However, in both the Y-maze test and the open field test, SPS-applied mice tended toward slight decreases in a time-dependent manner until 12 weeks. Therefore, SPS-applied mice may thus be useful for assessing characteristics relevant to PTSD that coincide with changes in the HPA axis.

DOI： 10.18926/AMO/56245

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/1028415x.2016.1253171

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s00210-016-1338-z

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Toxicology  

DOI： 10.2131/fts.4.37

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DOI： 10.4236/apd.2017.63010

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Bentham Science Publishers B.V.  

Parkinson’s disease (PD) is one of common neurodegenerative diseases, which shows motor symptoms including tremor, bradykinesia, rigidity and postural instability. It also involves non-motor symptoms such as cognitive impairment, mental manifestation, autonomic disorder and sensory disturbance. Although treatments to improve the motor disability in PD are being assessed at present, the main challenge remains that is the development of neuroprotective or disease-modifying treatments. Therefore, it is desirable to find approaches that can inhibit the progression of dopaminergic neurodegeneration. Astrocytes are known to play an important role in the maintenance of the neuronal environment and exert neuroprotective effects. Additionally, astrocyte dysfunction increases the susceptibility of neurons to cytotoxicity. We have demonstrated neuroprotective approaches in parkinsonian models in various studies targeting astrocytes. In this article, we summarize the neuroprotective function of astrocytes in the brain, involvement of astrocyte dysfunction in neurodegeneration, and experimental approaches to dopaminergic neuroprotection. We review findings reported in several papers including our own studies. We also address target molecules and pivotal pathways in astrocytes for dopaminergic neuroprotection. The review discusses new promising therapeutic strategies to prevent dopaminergic neurodegeneration in PD.

DOI： 10.2174/1381612823666170710163731

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DOI： 10.1186/s12868-016-0289-0

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Authorship：Last author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：The Society for Free Radical Research Japan  

DOI： 10.3164/jcbn.16-15

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DOI： 10.1007/s11356-016-6332-y

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Authorship：Last author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/jnc.13405

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.expneurol.2015.11.003

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Publishing type：Research paper (scientific journal)   Publisher：Society for Hard Tissue Regenerative Biology  

DOI： 10.2485/jhtb.25.21

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：BENTHAM SCIENCE PUBL LTD  

Astrocytes are the most abundant neuron-supporting glial cells in the central nervous system. The neuroprotective role of astrocytes has been demonstrated in various neurological disorders such as amyotrophic lateral sclerosis, spinal cord injury, stroke and Parkinson's disease (PD). Astrocyte dysfunction or loss-of-astrocytes increases the susceptibility of neurons to cell death, while astrocyte transplantation in animal studies has therapeutic advantage. We reported recently that stimulation of serotonin 1A (5-HT1A) receptors on astrocytes promoted astrocyte proliferation and upregulated antioxidative molecules to act as a neuroprotectant in parkinsonian mice. PD is a progressive neurodegenerative disease with motor symptoms such as tremor, bradykinesia, rigidity and postural instability, that are based on selective loss of nigrostriatal dopaminergic neurons, and with non-motor symptoms such as orthostatic hypotension and constipation based on peripheral neurodegeneration. Although dopaminergic therapy for managing the motor disability associated with PD is being assessed at present, the main challenge remains the development of neuroprotective or disease-modifying treatments. Therefore, it is desirable to find treatments that can reduce the progression of dopaminergic cell death. In this article, we summarize first the neuroprotective properties of astrocytes targeting certain molecules related to PD. Next, we review neuroprotective effects induced by stimulation of 5-HT1A receptors on astrocytes. The review discusses new promising therapeutic strategies based on neuroprotection against oxidative stress and prevention of dopaminergic neurodegeneration.

DOI： 10.2174/0929867323666160122115057

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DOI： 10.1016/j.bbr.2015.06.007

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DOI： 10.1007/s11064-015-1577-2

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.neulet.2014.12.052

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Language：Japanese  

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Other Link： http://search.jamas.or.jp/link/ui/2015129550

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

In vertebrates, almost all somatic cells extend a single immotile cilium, referred to as a primary cilium. Increasing evidence suggests that primary cilia serve as cellular antennae in many types of tissues by sensing chemical or mechanical stimuli in the milieu surrounding the cells. In rodents an antibody to adenylyl cyclase 3 (AC3) has been widely used to label the primary cilia of neurons in vivo by immunostaining, whereas the lack of markers for the primary cilia of astrocytes has made it difficult to observe astrocytic primary cilia in vivo. Here, we obtained a visualization of astrocytic primary cilia in the mouse brain. In the somatosensory cortex, a large portion of neurons and astrocytes at postnatal day 10 (P10), and of neurons at P56 had AC3-positive primary cilia, whereas only approx. one-half of the astrocytes in the P56 mice carried primary cilia weakly positive for AC3. In contrast, the majority of astrocytes had ADP-ribosylation factor-like protein 13B (Arl13b)-positive primary cilia in the somatosensory cortex and other brain regions of P56 mice. The lengths of astrocytic primary cilia positive for Arl13b varied among the brain regions. Our data indicate that Arl13b is a noteworthy marker of astrocytic primary cilia in the brain.

DOI： 10.18926/AMO/53020

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DOI： 10.1111/epi.12750

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s12640-014-9480-1

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Public Library of Science (PLoS)  

DOI： 10.1371/journal.pone.0106362

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

In the present study, we examined the effect of ACTH on the immobilization of rats in the forced swim test and hippocampal cell proliferation after administration of the 5-HT1A receptor agonist, R-(+)-8-hydroxy-2-di-n-propylamino tetralin ((+)-8-OH-DPAT). Chronic treatment with (+)-8-OH-DPAT (0.01-0.1 mg/kg, s.c.) significantly decreased the duration of immobility in saline- and ACTH-treated rats. Chronic administration of ACTH caused a significant decrease in hippocampal cell proliferation. However, (+)-8-OH-DPAT significantly normalized cell proliferation in ACTH-treated rats. We then investigated the effects of (+)-8-OH-DPAT on the expression of brain-derived neurotrophic factor (BDNF) and cyclin D1 (elements of cyclic adenosine monophosphate response element-binding protein (CREB)-BDNF and Wnt signaling pathways, respectively) in the hippocampus of saline- and ACTH-treated rats. ACTH treatment significantly decreased the expression of cyclin D1, while treatment with (+)-8-OH-DPAT normalized the expression of cyclin D1 in ACTH-treated rats. However, the expression of BDNF did not change in either saline- or ACTH-treated rats. These findings suggest that the antidepressant effects of (+)-8-OH-DPAT in treatment-resistant animals may be attributed to an enhancement of hippocampal cell proliferation, at least in part due to an enhancement of cyclin D1 expression. (C) 2014 Elsevier Inc All rights reserved.

DOI： 10.1016/j.pbb.2014.04.003

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In the rodent brain, certain G protein-coupled receptors and adenylyl cyclase type 3 are known to localize to the neuronal primary cilium, a primitive sensory organelle protruding singly from almost all neurons. A recent chemical screening study demonstrated that many compounds targeting dopamine receptors regulate the assembly of Chlamydomonas reinhardtii flagella, structures which are analogous to vertebrate cilia. Here we investigated the effects of dopaminergic inputs loss on the architecture of neuronal primary cilia in the rodent striatum, a brain region that receives major dopaminergic projections from the midbrain. We first analyzed the lengths of neuronal cilia in the dorsolateral striatum of hemi-parkinsonian rats with unilateral lesions of the nigrostriatal dopamine pathway. In these rats, the striatal neuronal cilia were significantly longer on the lesioned side than on the non-lesioned side. In mice, the repeated injection of reserpine, a dopamine-depleting agent, elongated neuronal cilia in the striatum. The combined administration of agonists for dopamine receptor type 2 (D2) with reserpine attenuated the elongation of striatal neuronal cilia. Repeated treatment with an antagonist of D2, but not of dopamine receptor type 1 (D1), elongated the striatal neuronal cilia. In addition, D2-null mice displayed longer neuronal cilia in the striatum compared to wild-type controls. Reserpine treatment elongated the striatal neuronal cilia in D1-null mice but not in D2-null mice. Repeated treatment with a D2 agonist suppressed the elongation of striatal neuronal cilia on the lesioned side of hemi-parkinsonian rats. These results suggest that the elongation of striatal neuronal cilia following the lack of dopaminergic inputs is attributable to the absence of dopaminergic transmission via D2 receptors. Our results provide the first evidence that the length of neuronal cilia can be modified by the lack of a neurotransmitter's input.

DOI： 10.1371/journal.pone.0097918

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

The specific toxicity to dopaminergic neurons of psychostimulants and neurotoxins has been extensively studied in vivo and in vitro, and findings have been used to establish animal models of amphetamine psychosis or Parkinson's disease. The multiple mechanisms of neurotoxicity operating in these disorders are known to involve oxidative stress or neuroinflammation, producing the characteristic behavioral and neuropathlogical changes arising from injured dopaminergic neurons and glial cells. A number of studies have shown that glia-targeting antioxidants play important roles in protecting against the neurotoxicity caused by psychostimulants or neurotoxins. Phytochemicals, which are non-nutritive plant chemicals, protect dopaminergic neurons and glial cells from damage caused by psychostimulants or neurotoxins. The objective of this review was to evaluate the involvement of glial cells in dopaminergic neuron specific toxicity and to explore the neuroprotective activity of phytochemicals in terms of anti-inflammatory and antioxidant action.

DOI： 10.1254/jphs.13R19CP

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

The dopamine reuptake inhibitor bupropion and dopamine D2/3 receptor agonist pramipexole have been clinically proven to improve both depression and treatment-resistant depression. We examined its influence on the duration of immobility during the forced swim test in adrenocorticotropic hormone (ACTH)-treated rats and further analyzed the possible role of the dopamine nerve system in this effect. Bupropion and pramipexole significantly decreased the duration of immobility in normal and ACTH-treated rats. We previously demonstrated that the chronic administration of ACTH caused a significant decrease in hippocampal cell proliferation and neurogenesis. In this study, we used the mitotic marker 5-bromo-2'-deoxyridine to investigate the effects of bupropion and pramipexole on cell proliferation in the subgranular zone of the hippocampal dentate gyms following chronic treatment with ACTH. The ACTH treatment for 14 d decreased adult hippocampal cell proliferation. The chronic administration of bupropion for 14 d blocked the loss of cell proliferation resulting from the chronic treatment with ACTH, whereas pramipexole did not. The administration of bupropion may have treatment-resistant antidepressive properties, which may be partly attributed to the normalization of hippocampal cell proliferation.

DOI： 10.1248/bpb.b13-00749

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Physiological Society  

Oxidative stress and inflammation play important roles in diabetic complications, including diabetic nephropathy. Metallothionein (MT) is induced in proximal tubular epithelial cells as an antioxidant in the diabetic kidney; however, the role of MT in renal function remains unclear. We therefore investigated whether MT deficiency accelerates diabetic nephropathy through oxidative stress and inflammation. Diabetes was induced by streptozotocin injection in MT-deficient (MT^−/−) and MT^+/+ mice. Urinary albumin excretion, histological changes, markers for reactive oxygen species (ROS), and kidney inflammation were measured. Murine proximal tubular epithelial (mProx24) cells were used to further elucidate the role of MT under high-glucose conditions. Parameters of diabetic nephropathy and markers of ROS and inflammation were accelerated in diabetic MT^−/− mice compared with diabetic MT^+/+ mice, despite equivalent levels of hyperglycemia. MT deficiency accelerated interstitial fibrosis and macrophage infiltration into the interstitium in the diabetic kidney. Electron microscopy revealed abnormal mitochondrial morphology in proximal tubular epithelial cells in diabetic MT^−/− mice. In vitro studies demonstrated that knockdown of MT by small interfering RNA enhanced mitochondrial ROS generation and inflammation-related gene expression in mProx24 cells cultured under high-glucose conditions. The results of this study suggest that MT may play a key role in protecting the kidney against high glucose-induced ROS and subsequent inflammation in diabetic nephropathy.

DOI： 10.1152/ajprenal.00034.2013

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (bulletin of university, research institution)  

DOI： 10.4044/joma.126.203

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Astrocytes are abundant neuron-supporting glial cells that harbor a powerful arsenal of neuroprotective antioxidative molecules and neurotrophic factors. Here we examined whether enrichment with healthy striatal astrocytes can provide neuroprotection against progressive dopaminergic neurodegeneration. Serotonin 1A (5-HT1A) agonist 8-OH-DPAT induced astrocyte proliferation and increased metallothionein-1/-2 (MT-1/-2), antioxidative molecules, in cultured astrocytes and the striatum of mice. Primary cultured mesencephalic dopamine neurons were protected against oxidative stress by preincubation with conditioned media from 8-OH-DPAT-treated astrocytes. These protective effects were canceled by 5-HT1A antagonist or MT-1/-2-specific antibody. Furthermore, reduction of nigrostriatal dopaminergic neurons in 6-hydroxydopamine-lesioned parkinsonian model mice was significantly abrogated by repeated injections of 8-OH-DPAT. Treatment with 8-OH-DPAT markedly increased the expression of MT in striatal astrocytes in the hemi-parkinsonian mice. Our study provides a promising therapeutic strategy of neuroprotection against oxidative stress and progressive dopaminergic neurodegeneration by demonstrating the efficacy of targeting 5-HT1A receptors in astrocytes. © 2013 Elsevier Inc.

DOI： 10.1016/j.nbd.2013.08.003

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Public Library of Science (PLoS)  

DOI： 10.1371/journal.pone.0065983

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Aims Cisplatin (CDDP) is a potent anticancer agent, but severe renal toxicity can limit its use. We investigated the protective effect of cepharanthin (CE), a biscoclaurin alkaloid, on the renal toxicity of CDDP. Main methods Mice were given CDDP along with CE. Effects of CE on CDDP toxicity were investigated by assaying markers of renal toxicity together with MT expression, and by histopathological examination of the kidney. MT-null mice were also examined. Key findings CE induced expression of metallothionein (MT). Pre-administration of CE attenuated an increase in blood urea nitrogen (BUN) concentrations after the CDDP injection. A histochemical analysis demonstrated protection against CDDP-induced necrocytosis of kidney tissues by CE. The protective effect of CE did not occur in the MT-null mice. Significance Pretreatment with CE may reduce the renal toxicity of CDDP through expression of MT. © 2013 Elsevier Inc.

DOI： 10.1016/j.lfs.2013.01.031

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In clinical studies, electroconvulsive stimuli have been associated with improvements in both depression and treatment-resistant depression. In a previous study, treatment with adrenocorticotropic hormone (ACTH) for 14 days decreased adult hippocampal cell proliferation. Furthermore, electroconvulsive stimuli significantly decreased the duration of immobility following repeated administration of ACTH for 14 days in rats. The present study was undertaken to further characterize the mechanism of treatment-resistant antidepressant effects of electroconvulsive stimuli by measuring cell proliferation, brain-derived neurotrophic factor (BDNF) levels, and phosphorylated and total cyclic adenosine monophosphate (cAMP) response element-binding protein (pCREB/CREB) levels in the hippocampus of ACTH-treated rats. Electroconvulsive stimuli increased cell proliferation in both saline-treated and ACTH-treated rats. Mature-BDNF protein levels showed a tendency to decrease in ACTH-treated rats. Electroconvulsive stimuli treatment increased mature-BDNF protein levels in the hippocampus of both saline-treated and ACTH-treated rats. Furthermore, electroconvulsive stimuli increased phospho-Ser133-CREB (pCREB) levels and the ratio of pCREB/CREB in both saline-treated and ACTH-treated rats. These findings suggest that the treatment-resistant antidepressant effects of electroconvulsive stimuli may be attributed, at least in part, to an enhancement of hippocampal cell proliferation. © The Japanese Pharmacological Society.

DOI： 10.1254/jphs.13015FP

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Lewy bodies containing the centrosomal protein gamma-tubulin and fragmentation of Golgi apparatus (GA) have been described in nigral neurons of Parkinson's disease (PD) patients. However, the relevance of these features in PD pathophysiology remains unknown. We analyzed the impact of proteasome inhibition in the formation of gamma-tubulin-containing aggregates as well as on GA structure. SH-SY5Y cells were treated with the proteasome inhibitor Z-Leu-Leu-Leu-al (MG132) to induce centrosomal-protein aggregates. Then, microtubules (MTs) and Golgi dynamics, as well as the vesicular transport of dopamine transporter (DAT) were evaluated both in vitro and in living cells. MG132 treatment induced gamma-tubulin aggregates which altered microtubule nucleation. MG132-treated cells containing gamma-tubulin aggregates showed fragmentation of GA and perturbation of the trans-Golgi network. Under these conditions, the DAT accumulated at the centrosomal-Golgi region indicating that the vesicular transport of DAT was disrupted. Thus, centrosomal aggregates and fragmentation of GA are 2 closely related processes that could result in the disruption of the vesicular transport of DAT toward the plasma membrane in a model of dopaminergic neuronal degeneration. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.neurobiolaging.2011.11.014

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER/PLENUM PUBLISHERS  

Prostaglandin H synthase exerts not only cyclooxygenase activity but also peroxidase activity. The latter activity of the enzyme is thought to couple with oxidation of dopamine to dopamine quinone. Therefore, it has been proposed that cyclooxygenase inhibitors could suppress dopamine quinone formation. In the present study, we examined effects of various cyclooxygenase inhibitors against excess methyl L-3,4-dihydroxyphenylalanine (L-DOPA)-induced quinoprotein (protein-bound quinone) formation and neurotoxicity using dopaminergic CATH.a cells. The treatment with aspirin inhibited excess methyl L-DOPA-induced quinoprotein formation and cell death. However, acetaminophen did not show protective effects, and indomethacin and meloxicam rather aggravated these methyl L-DOPA-induced changes. Aspirin and indomethacin did not affect the level of glutathione that exerts quenching dopamine quinone in dopaminergic cells. In contrast with inhibiting effects of higher dose in the previous reports, relatively lower dose of aspirin that affected methyl L-DOPA-induced quinoprotein formation and cell death failed to prevent cyclooxygenase-induced dopamine chrome generation in cell-free system. Furthermore, aspirin but not acetaminophen or meloxicam showed direct dopamine quinone-scavenging effects in dopamine-semiquinone generating systems. The present results suggest that cyclooxygenase shows little contribution to dopamine oxidation in dopaminergic cells and that protective effects of aspirin against methyl L-DOPA-induced dopamine quinone neurotoxicity are based on its cyclooxygenase-independent property.

DOI： 10.1007/s11064-012-0813-2

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MULTIMED INC  

Objective: Residual renal function (RRF) is associated with low oxidative stress in peritoneal dialysis (PD). In the present study, we investigated the relationship between the impact of oxidative stress on RRF and patient outcomes during PD.
Methods: Levels of free radicals (FRs) in effluent from the overnight dwell in 45 outpatients were determined by electron spin resonance spectrometry. The FR levels, clinical parameters, and the level of 8-hydroxy-2'-deoxyguanosine were evaluated at study start. The effects of effluent FR level on technique and patient survival were analyzed in a prospective cohort followed for 24 months.
Results: Levels of effluent FRs showed significant negative correlations with daily urine volume and residual renal Kt/V, and positive correlations with plasma beta(2)-microglobulin and effluent 8-hydroxy-2'-deoxyguanosine. A highly significant difference in technique survival (p &lt; 0.05), but not patient survival, was observed for patients grouped by effluent FR quartile. The effluent FR level was independently associated with technique failure after adjusting for patient age, history of cardiovascular disease, and presence of diabetes mellitus (p &lt; 0.001). The level of effluent FRs was associated with death-censored technique failure in both univariate (p &lt; 0.001) and multivariate (p &lt; 0.01) hazard models. Compared with patients remaining on PD, those withdrawn from the modality had significantly higher levels of effluent FRs (p &lt; 0.005).
Conclusions: Elevated effluent FRs are associated with RRF and technique failure in stable PD patients. These findings highlight the importance of oxidative stress as an unfavorable prognostic factor in PD and emphasize that steps should be taken to minimize oxidative stress in these patients. Perit Dial Int 2012; 32(4): 453-461

DOI： 10.3747/pdi.2011.00032

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MANEY PUBLISHING  

Objectives and methods: We have searched for low-molecular-weight compounds as potent new non-immunosuppressive immunophilin ligands (NI-IPLs) that are stronger than existent NI-IPLs such as GPI1046 and/or V10367 from the perspective of neuroprotective efficacy. We selected six dipeptidyl compounds as new NI-IPL candidates, and first examined the effects of each of these compounds on the serum-deprivation-induced reduction in the viability of SH-SY5Y cells. In addition, we clarified the effects of these compounds on neurotrophin release into medium in SH-SY5Y cells.
Results: Pre-treatment with Leu-Ile and Ile-Ile prevented the serum deprivation-induced reduction in cell viability in SH-SY5Y cells. In naive SH-SY5Y cells, treatment with Leu-Ile and Ile-Ile for 24 hours significantly increased both brain-derived neurotrophic factor and glial cell-line-derived neurotrophic factor releases in comparison with relative vehicle treatments. Moreover, none of the dipeptidyl compounds could prevent the concanavalin A-induced enhancement in interleukin-2 and interleukin-4 release in mouse spleen cells.
Discussion: The immunosuppressive effect is not essential to the neuroprotective properties of dipeptidyl compounds, and Leu-Ile and Ile-Ile have neurotrophin-activating effects, like FK506 and its existing non-immunosuppressive derivatives.

DOI： 10.1179/1743132812Y.0000000001

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：The Pharmaceutical Society of Japan  

We previously reported that adrenocorticotropic hormone (ACTH)-treated rats serve as a valuable animal model for tricyclic antidepressant-resistant depressive conditions. The present study was undertaken to investigate the changes in neurogenesis in the hippocampus of ACTH-treated rats. Chronic treatment of ACTH decreased the number of bromodeoxyuridine-labeled cells in the dentate gyrus, and the coadministration of imipramine and lithium, and electroconvulsive stimuli recovered these reductions. Furthermore, chronic ACTH treatment also decreased the expression of brain-derived neurotrophic factor, and the coadministration of imipramine and lithium, and electroconvulsive stimuli recovered these reductions. These results suggest that antidepressant-resistant depression is caused by the suppression of neurogenesis, and the coadministration of imipramine and lithium, and electroconvulsive stimuli exert an antidepressant-like effect by recovering proliferative signals and neurogenesis.<br>

DOI： 10.1248/yakushi.132.173

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MANEY PUBLISHING  

Objectives: Baicalein, a flavonoid derived from the root of Scutelaria baicalensis Georgi, possesses antioxidative properties including reactive oxygen species scavenging and lipid peroxidation inhibiting activities. The present study was undertaken to investigate the neuroprotective effect of baicalein against dopamine (DA) neurotoxicity induced by exposure to a synthetic DA precursor, L-3,4-dihydroxyphenylalanine (L-DOPA), in cultured dopaminergic CATH. a cells.
Methods and results: Exposure to L-DOPA for 24 hours reduced the number of viable cells and enhanced protein-bound quinone (quinoprotein) formation in the cell. Both effects were prevented by simultaneous treatment with baicalein. In addition, baicalein prevented the formation of DA semiquinone radicals from DA in an in vitro cell-free system. Long-term baicalein treatment for 96 hours also protected against excess L-DOPA-induced cell death, and also increased glutathione (GSH) levels in CATH. a cells.
Discussion: Our results indicate that baicalein has neuroprotective properties against excess L-DOPA-induced DA neurotoxicity through the suppression of DA quinone formation. Furthermore, the long-term treatment of baicalein upregulates intracellular GSH contents, which may also exert neuroprotective effects against oxidative stress-induced neuronal damage.

DOI： 10.1179/1743132811Y.0000000032

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

Almost all mammalian cells carry one primary cilium that functions as a biosensor for chemical and mechanical stimuli. Genetic damages that compromise cilia formation or function cause a spectrum of disorders referred to as ciliapathies. Recent studies have demonstrated that some pharmacological agents and extracellular environmental changes can alter primary cilium length. Renal injury is a well-known example of an environmental insult that triggers cilia length modification. Lithium treatment causes primary cilia to extend in several cell types including neuronal cells; this phenomenon is likely independent of glycogen synthase kinase-3 beta inhibition. In renal epithelial cell lines, deflection of the primary cilia by fluid shear shortens them by reducing the intracellular cyclic AMP level, leading to a subsequent decrease in mechanosensitivity to fluid shear. Primary cilium length is also influenced by the dynamics of actin filaments and microtubules through the levels of soluble tubulin in the cytosol available for primary cilia extension. Thus, mammalian cells can adapt to the extracellular environment by modulating the primary cilium length, and this feedback system utilizing primary cilia might exist throughout the mammalian body. Further investigation is required concerning the precise molecular mechanisms underlying the control of primary cilium length in response to environmental factors.

DOI： 10.18926/AMO/47009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Negative motivational withdrawal from acute opiate dependence was induced by an opioid antagonist, and the withdrawal signs prevented by pretreatment with nicotine.
The present study was undertaken to examine the mechanism of nicotine-induced attenuation of withdrawal precipitated by naloxone in rats administered a single dose of morphine.
Conditioned place aversion (CPA) was precipitated by naloxone in rats exposed once to morphine. Nicotinic acetylcholine receptor (nAChR) agonists were microinjected into the central amygdaloid nucleus (CeA) before naloxone was administered. Additionally, c-Fos expression in the amygdala was measured in rats exposed to alpha 7 nAChR ligands.
The microinjection of nicotine (0.3 and 1.0 mu g/mu l) into the CeA dose-dependently inhibited naloxone-induced CPA. This inhibition of CPA was reversed by methyllycaconitine (MLA), an alpha 7 nAChR antagonist. CPA was also significantly attenuated by the microinjection of tropisetron (3.0 mu g/mu l), an alpha 7 nAChR agonist and 5-hydroxytriptamine 3 (5-HT3) receptor antagonist, but not by ondansetron (1.0 and 3.0 mu g/mu l), a 5-HT3 receptor antagonist. The microinjection of PNU-282987 (3.0 mu g/mu l), a selective alpha 7 nAChR agonist, into the CeA also inhibited CPA. Furthermore, nicotine increased c-Fos expression in the CeA, but not the medial or basolateral amygdaloid nucleus. The increase of c-Fos in the CeA was significantly inhibited by MLA.
Nicotine-induced attenuation of CPA precipitated by naloxone is mediated by the alpha 7 nAChR subtype, and the CeA is one of the regions of the brain involved in the effect of nicotine on acutely opiate-dependent subjects.

DOI： 10.1007/s00213-010-2101-7

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Our previous studies demonstrated the involvement of quinone formation in dopaminergic neuron dysfunction in the L-DOPA-treated parkinsonian model and in methamphetamine (METH) neurotoxicity. We further reported that the cysteine-rich metal-binding metallothionein (MT) family of proteins protects dopaminergic neurons against dopamine (DA) quinone neurotoxicity by its quinone-quenching property. The aim of this study was to examine MT induction in astrocytes in response to excess DA and the potential neuroprotective effects of astrocyte-derived MTs against DA quinone toxicity. DA exposure significantly upregulated MT-1/-2 in cultured striatal astrocytes, but not in mesencephalic neurons. This DA-induced MT upregulation in astrocytes was blocked by treatment with a DA-transporter (DAT) inhibitor, but not by DA-receptor antagonists. Expression of nuclear factor erythroid 2-related factor (Nrf2) and its binding activity to antioxidant response element of MT-1 gene were significantly increased in the astrocytes after DA exposure. Nuclear translocation of Nrf2 was suppressed by the DAT inhibitor. Quinone formation and reduction of mesencephalic DA neurons after DA exposure were ameliorated by preincubation with conditioned media from DA-treated astrocytes. These protective effects were abrogated by MT-1/-2-specific antibody. Adding exogenous MT-1 to glial conditioned media also showed similar neuroprotective effects. Furthermore, MT-1/-2 expression was markedly elevated specifically in reactive astrocytes in the striatum of L-DOPA-treated hemi-parkinsonian mice or METH-injected mice. These results suggested that excess DA taken up by astrocytes via DAT upregulates MT-1/-2 expression specifically in astrocytes, and that MTs or related molecules secreted specifically by astrocytes protect dopaminergic neurons from damage through quinone quenching and/or scavenging of free radicals. (C)2010 Wiley-Liss, Inc.

DOI： 10.1002/glia.21112

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

Adult hippocampal neurogenesis is reported to change in animal models of depression and antidepressants. We have used the mitotic marker 5-bromo-2'-deoxyyridine to address the effects of imipramine and lithium on cell proliferation and survival following chronic treatment with adrenocorticotropic hormone (ACTH) in the subgranular zone of the hippocampal dentate gyrus. ACTH treatment for 14d decreased adult hippocampal cell proliferation and survival. Coadministration of imipramine and lithium for 14d blocked the loss of cell proliferation but not cell survival resulting from the chronic treatment with ACTH. The coadministration of imipramine and lithium may have treatment-resistant antidepressive properties, which may be attributed, in part, to a normalization of hippocampal cell proliferation.

DOI： 10.1248/bpb.34.77

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HINDAWI PUBLISHING CORPORATION  

Metallothionein(MT) is an intracellular metal-binding, cysteine-rich protein, and is a potent antioxidant that protects cells and tissues from oxidative stress. Although the major isoforms MT-1 and -2 (MT-1/-2) are highly inducible in many tissues, the distribution and role of MT-1/-2 in diabetic nephropathy are poorly understood. In this study, diabetes was induced in adult male rats by streptozotocin, and renal tissues were stained with antibodies for MT-1/-2. MT-1/-2 expression was also evaluated in mProx24 cells, a mouse renal proximal tubular epithelial cell line, stimulated with high glucose medium and pretreated with the antioxidant vitamin E. MT-1/-2 expression was gradually and dramatically increased, mainly in the proximal tubular epithelial cells and to a lesser extent in the podocytes in diabetic rats, but was hardly observed in control rats. MT-1/-2 expression was also increased by high glucose stimulation in mProx24 cells. Because the induction of MT was suppressed by pretreatment with vitamin E, the expression of MT-1/-2 is induced, at least in part, by high glucose-induced oxidative stress. These observations suggest that MT-1/-2 is induced in renal proximal tubular epithelial cells as an antioxidant to protect the kidney from oxidative stress, and may offer a novel therapeutic target against diabetic nephropathy.

DOI： 10.1155/2011/534872

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

We examined the influence of chronic adrenocorticotropic hormone (ACTH) treatment on the number of Ki-67-positive cells in the dentate gyrus of the hippocampus in rats. ACTH treatment for 14 days decreased the number of such cells. The administration of imipramine or lithium alone for 14 days had no effect in saline-treated rats. The effect of ACTH was blocked by the administration of imipramine. Furthermore, the coadministration of imipramine and lithium for 14 days significantly increased the number of Ki-67-positive cells in both the saline and ACTH-treated rats. The coadministration of imipramine and lithium normalized the cell proliferation in the dentate gyrus of the hippocampus in rats treated with ACTH.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

The dopamine reuptake inhibitor bupropion has clinically been proven to improve depression and treatment-resistant depression. We examined its influence on the duration of immobility during the forced swim test in adrenocorticotropic hormone (ACTH)-treated rats and further analyzed the possible role of dopamine receptors in this effect. Additionally, the mechanism by which bupropion acts in this model was explored specifically in relation to the site of action through the use of microinjections into the medial prefrontal cortex and nucleus accumbens. Bupropion significantly decreased the duration of immobility in normal and ACTH-treated rats. This effect was blocked by D2 and D3 receptor antagonists in normal rats. Furthermore, infusions of bupropion into the nucleus accumbens, but not medial prefrontal cortex, decreased the immobility of normal and ACTH-treated rats during the forced swim test. Bupropion treatment plus repeated ACTH treatment significantly increased the extracellular dopamine concentration. These findings suggest the antidepressant-like effect of bupropion to be related to levels of dopamine in the rat nucleus accumbens.

DOI： 10.1007/s00210-010-0521-x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Amyotrophic lateral sclerosis is a progressive and fatal disease caused by selective death of motor neurons, and a number of these patients carry mutations in the superoxide dismutase 1 (SOD1) gene involved in ameliorating oxidative stress. Recent studies indicate that oxidative stress and disruption of mitochondrial homeostasis is a common mechanism for motor neuron degeneration in amyotrophic lateral sclerosis and the loss of midbrain dopamine neurons in Parkinson&apos;s disease. Therefore, the present study investigated the presence and alterations of familial Parkinson&apos;s disease-related proteins, PINK1 and DJ-1, in spinal motor neurons of G93ASOD1 transgenic mouse model of amyotrophic lateral sclerosis. Following onset of disease, PINK1 and DJ-1 protein expression increased in the spinal motor neurons. The activated form of p53 also increased and translocated to the nuclei of spinal motor neurons, followed by increased expression of p53-activated gene 608 (PAG608). This is the first report demonstrating that increased expression of PAG608 correlates with activation of phosphorylated p53 in spinal motor neurons of an amyotrophic lateral sclerosis model. These results provide further evidence of the profound correlations between spinal motor neurons of amyotrophic lateral sclerosis and parkinsonism-related proteins. (C) 2010 Wiley-Liss, Inc.

DOI： 10.1002/jnr.22341

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-LISS  

Objective: Recent double-blind, controlled trials in Japan showed that the antiepileptic agent zonisamide (ZNS)improves the cardinal symptoms of Parkinson&apos;s disease. Glutathione (GSH) exerts antioxidative activity through quenching reactive oxygen species and dopamine quinone. GSH depletion within dopaminergic neurons impairs mitochondrial complex I activity, followed by age-dependent nigrostriatal neurodegeneration. This study examined changes in GSH and GSH synthesis-related molecules, and the neuroprotective effects of ZNS on dopaminergic neurodegeneration using 6-hydroxydopamine-injected hemiparkinsonian mice brain and cultured neurons or astrocytes.
Methods and Results: ZNS increased both the cell number and GSH levels in astroglial C6 cells, but not in dopaminergic neuronal CATH.a cells. Repeated injections of ZNS (30mg/kg intraperitoneally) for 14 days also significantly increased GSH levels and S100 beta-positive astrocytes in mouse basal ganglia. Repeated ZNS injections (30mg/kg) for 7 days in the hemiparkinsonian mice increased the expression of cystine/glutamate exchange transporter xCT in activated astrocytes, which supply cysteine to neurons for GSH synthesis. Treatment of these mice with ZNS also increased GSH levels and completely suppressed striatal levodopa-induced quinone formation. Reduction of nigrostriatal dopamine neurons in the lesioned side of hemiparkinsonian mice was significantly abrogated by repeated injections of ZNS with or without adjunctive levodopa starting 3 weeks after 6-hydroxydopamine lesioning.
Interpretation: These results provide new pharmacological evidence for the effects of ZNS. ZNS markedly increased GSH levels by enhancing the astroglial cystine transport system and/or astroglial proliferation via S100 beta production or secretion. ZNS acts as a neuroprotectant against oxidative stress and progressive dopaminergic neurodegeneration. ANN NEUROL 2010;67:239-249

DOI： 10.1002/ana.21885

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Language：English   Publishing type：Research paper (bulletin of university, research institution)  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

The molecular mechanisms underlying the therapeutic effects of lithium, a first-line antimanic mood stabilizer, have not yet been fully elucidated. Treatment of the algae Chlamydomonas reinhardtii with lithium has been shown to induce elongation of their flagella, which are analogous structures to vertebrate cilia. In the mouse brain, adenylyl cyclase 3 (AC3) and certain neuropeptide receptors colocalize to the primary cilium of neuronal cells, suggesting a chemosensory function for the primary cilium in the nervous system. Here we show that lithium treatment elongates primary cilia in the mouse brain and in cultured cells. Brain sections from mice chronically fed with Li(2)CO(3) were subjected to immunofluorescence study. Primary cilia carrying both AC3 and the receptor for melanin-concentrating hormone (MCH) were elongated in the dorsal striatum and nucleus accumbens of lithium-fed mice, as compared to those of control animals. Moreover, lithium-treated NIH3T3 cells and cultured striatal neurons exhibited elongation of the primary cilia. The present results provide initial evidence that a psychotropic agent can affect ciliary length in the central nervous system, and furthermore suggest that lithium exerts its therapeutic effects via the upregulation of cilia-mediated MCH sensing. These findings thus contribute novel insights into the pathophysiology of bipolar mood disorder and other psychiatric diseases. (C) 2009 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2009.08.099

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

Nitric oxide (NO) may play a role in the established processes of learning and memory. We examined the effects of N-omega-nitro-L-arginine methylester (L-NAME), a nonselective inhibitor of NO synthase (NOS), on the performance of mice in a Y-maze task. L-NAME (100 mg/kg) markedly impaired spontaneous alternation behavior. However, galantamine (0.5 mg/kg) significantly attenuated this L-NAME-induced impairment. To clarify the molecular basis underlying galantamine's protective effects against L-NAME-induced impairment of spontaneous alternation behavior, we tested the ability of mecamylamine, an antagonist of nicotinic ACh receptor (nAChR), and scopolamine, an antagonist of muscarinic ACh receptor, to reduce galantamine's protective effects, and found that only the former had such an ability. Galantamine significantly also reduced L-NAME-induced decreases in NOx levels. However, mecamylamine cancelled galantamine's efficacy in countering the L-NAME-induced decrease in NOx levels. In the present study, we have determined that galantamine's protection against L-NAME-induced impairment of spontaneous alternation behavior in the Y-maze task might be mediated mainly by NOergic activation via the nAChR-related pathway. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.neulet.2009.07.024

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：FEDERATION AMER SOC EXP BIOL  

The Drosophila pericentrin-like protein has been shown to be essential for the formation of the sensory cilia of chemosensory and mechanosensory neurons by mutant analysis in flies, while the in vivo function of pericentrin, a well-studied mammalian centrosomal protein related to microcephalic primordial dwarfism, has been unclear. To determine whether pericentrin is required for ciliogenesis in mammals, we generated and analyzed mice with a hypomorphic mutation of Pcnt encoding the mouse pericentrin. Immunofluorescence analysis demonstrated that olfactory cilia of chemosensory neurons in the nasal olfactory epithelium were malformed in the homozygous mutant mice. On the other hand, the assembly of motile and primary cilia of non-neuronal epithelial cells and the formation of sperm flagella were not affected in the Pcnt-mutant mice. The defective assembly of olfactory cilia in the mutant was apparent from birth. The mutant animals displayed reduced olfactory performance in agreement with the compromised assembly of olfactory cilia. Our findings suggest that pericentrin is essential for the assembly of chemosensory cilia of olfactory receptor neurons, but it is not globally required for cilia formation in mammals.-Miyoshi, K., Kasahara, K., Miyazaki, I., Shimizu, S., Taniguchi, M., Matsuzaki, S., Tohyama, M., Asanuma, M. Pericentrin, a centrosomal protein related to microcephalic primordial dwarfism, is required for olfactory cilia assembly in mice. FASEB J. 23, 3289-3297 ( 2009). www.fasebj.org

DOI： 10.1096/fj.08-124420

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The dopamine D2/D3 receptor agonist pramipexole has clinically been proven to improve depression or treatment-resistant depression. However, the involvement of the dopamine receptor system on the effect of pramipexole on depression remains unclear. We examined the influence of pramipexole on the duration of immobility during the forced swim test in normal and adrenocorticotropic hormone (ACTH)-treated rats and further analyzed the possible role of dopamine receptors in this effect. Additionally, the mechanism by which pramipexole acts in this model was explored specifically in relation to the site of action through the use of microinjections into the intramedial prefrontal cortex and nucleus accumbens. Pramipexole (0.3-1 mg/kg) significantly decreased the duration of immobility in normal and ACTH-treated rats. This effect was blocked by L-741,626, a D2 receptor antagonist, and nafadotride, a D3 receptor antagonist, in normal rats. Furthermore, infusions of pramipexole into the intranucleus accumbens, but not the medial prefrontal cortex, decreased the immobility of normal and ACTH-treated rats during the forced swim test. Taken together, the results of these experiments suggested that pramipexole, administered into the intranucleus accumbens rather than the medial prefrontal cortex, exerted an antidepressant-like effect on ACTH-treated rats via the dopaminergic system. The immobility-decreasing effect of pramipexole may be mediated by dopamine D2 and D3 receptors.

DOI： 10.1007/s00210-009-0405-0

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Authorship：Last author   Language：English   Publisher：SPRINGER/PLENUM PUBLISHERS  

Dopamine (DA) and its metabolites containing two hydroxyl residues exert cytotoxicity in dopaminergic neuronal cells, primarily due to the generation of highly reactive DA and DOPA quinones. Quinone formation is closely linked to other representative hypotheses such as mitochondrial dysfunction, inflammation, oxidative stress, and dysfunction of the ubiquitin-proteasome system, in the pathogenesis of neurodegenerative diseases such as Parkinson&apos;s disease and methamphetamine-induced neurotoxicity. Therefore, pathogenic effects of the DA quinone have focused on dopaminergic neuron-specific oxidative stress. Recently, various studies have demonstrated that some intrinsic molecules and several drugs exert protective effects against DA quinone-induced damage of dopaminergic neurons. In this article, we review recent studies on some neuroprotective approaches against DA quinone-induced dysfunction and/or degeneration of dopaminergic neurons.

DOI： 10.1007/s11064-008-9843-1

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER/PLENUM PUBLISHERS  

We examined changes in nuclear peroxisome proliferator-activated receptor gamma (PPAR gamma) in the striatum in methamphetamine (METH)-induced dopaminergic neurotoxicity, and also examined effects of treatment with drugs possessing PPAR gamma agonistic properties. The marked reduction of nuclear PPAR gamma-expressed cells was seen in the striatum 3 days after METH injections (4 mg/kg x 4, i.p. with 2-h interval). The reduction of dopamine transporter (DAT)-positive signals and PPAR gamma expression, and accumulation of activated microglial cells were significantly and dose-dependently attenuated by four injections of a nonsteroidal anti-inflammatory drug and a PPAR gamma ligand, ibuprofen (10 or 20 mg/kg x 4, s.c.) given 30 min prior to each METH injection, but not by either a low or high dose of aspirin. Either treatment of ibuprofen or aspirin, that showed no effects on METH-induced hyperthermia, significantly blocked the METH-induced striatal cyclooxygenase (COX) expression. Furthermore, the treatment of an intrinsic PPAR gamma ligand 15d-PG J2 also attenuated METH injections-induced reduction of striatal DAT. Therefore, the present study suggests the involvement of reduction of PPAR gamma expression in METH-induced neurotoxicity. Taken together with the previous report showing protective effects of other PPAR gamma ligand, these results imply that the protective effects of ibuprofen against METH-induced neurotoxicity may be based, in part, on its anti-inflammatory PPAR gamma agonistic properties, but not on its COX-inhibiting property or hypothermic effect.

DOI： 10.1007/s11064-008-9863-x

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Publishing type：Part of collection (book)   Publisher：Elsevier  

DOI： 10.1016/s0074-7742(09)88003-3

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Aggregation of proteins in the centrosome is implicated in the pathophysiology of Parkinson&apos;s disease. However, the relevance of the centrosome in neurodegeneration is still obscure. Centrosome duplication is initiated by the cyclin E/cyclin-dependent kinase 2 (Cdk2) complex. The present study determined changes in cyclin E or Cdk2 expression and in the centrosomal structure in dopaminergic neuronal CATH.a cells exposed to 50, 100 and 150 mu M dopamine (DA) for 24 h. DA induced significant increase in Cdk2 protein and cyclin E protein, but not cyclin a mRNA. In DA-treated cells, the intense cyclin E- and Cdk2-immunofluorescence signals were co-localized around large and supernumerary centrosomes, and these two parameters of centrosome amplification were significantly increased compared with the control. Simultaneous co-treatment with DA and a Cdk2 inhibitor blocked centrosome amplification and enhanced cell viability. Our results demonstrated that DA could lead to cyclin E accumulation and Cdk2 up-regulation triggering supernumerary centrosomes and apoptotic cell death.

DOI： 10.1007/BF03033854

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：English   Publisher：ELSEVIER IRELAND LTD  

DOI： 10.1016/j.toxlet.2008.06.864

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE CIRCULATION SOC  

Background Coronary ischemia-reperfusion (I/R) injury causes cardiomyocyte necrosis in a multi-step process that includes an inflammatory reaction. A recent study has suggested that high-mobility group box 1 (HMGB 1) is a late mediator of lethal sepsis and an early mediator of inflammation and necrosis following I/R injury. In the present study a neutralizing monoclonal antibody (mAb) for HMGB1 was used to clarify the role of HMGB 1 in cardiac I/R injury.
Methods and Results Rats underwent 30 min of left coronary artery occlusion followed by 60 min reperfusion. An intravenous injection of anti-HMGB1 mAb or control IgG was administered just before reperfusion. The infarct size was enlarged in the anti-HMGB1 mAb group in comparison with the control group (p&lt;0.05). The treatment of anti-HMGB1 mAb significantly increased the plasma troponin-T and norepinephrine (NE) content in the heart in comparison with the control (p&lt;0.05). Moreover, the production of dihydroxyphenylglycol was reduced in the anti-HMGB1-treated group (p&lt;0.05).
Conclusion This study shows for the first time the effects of treatment with neutralizing anti-HMGB1 mAb on I/R injury in the rat heart. The findings support the novel view that I/R-induced HMGB1 may be an important factor in the modulation of interstitial NE.

DOI： 10.1253/circj.72.1178

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

Oxidative stress, including the reactive oxygen or nitrogen species generated in the enzymatical oxidation or auto-oxidation of an excess amount of dopamine, is thought to play an important role in dopaminergic neurotoxicity. Dopamine and its metabolites containing 2 hydroxyl residues exert cytotoxicity in dopaminergic neuronal cells, primarily due to the generation of highly reactive dopamine and DOPA quinones. Dopamine and DOPA quinones may irreversibly alter protein function through the formation of 5-cysteinyl-catechols on the proteins. Furthermore, the quinone formation is closely linked to other representative hypotheses such as mitochondrial dysfunction, inflammation, oxidative stress, and dysfunction of the ubiquitin-proteasome system, in the pathogenesis of neurodegenerative diseases. Therefore, pathogenic effects of the dopamine quinone have recently focused on dopaminergic neuron-specific oxidative stress. In this article, we primarily review recent studies on the pathogenicity of quinone formation, in addition to several neuroprotective approaches against dopamine quinone-induced dysfunction of dopaminergic neurons.

DOI： 10.18926/AMO/30980

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：BENTHAM SCIENCE PUBL LTD  

A number of experimental studies using parkinsonian models have revealed that nonsteroidal anti-inflammatory drugs (NSAIDs) have neuroprotective properties against dopaminergic neurotoxicity not only by their cyclooxygenase-inhibiting effect but also by other specific properties or some unknown pharmacological effects. This article reviews heterogeneous pharmacological properties of NSAIDs including inhibitory effect against nitric oxide synthesis, agonistic action for peroxisome proliferator-activated receptor or possible suppressive effects against dopamine quinone generation, and also reviews their neuroprotective effects in the experimental parkinsonian models and pathogenesis of Parkinson's disease. Several epidemiological studies recently clarified that the use of nonaspirin NSAIDs but not aspirin was associated with a lower prevalence of Parkinson's disease, in contrast with neuroprotective effects of aspirin in the experimental studies. It also discusses the discrepancy between results in the experimental parkinsonian models and epidemiological data in prevalence of Parkinson's disease on the effects of NSAIDs.

DOI： 10.2174/138161208784480153

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We identified p53-activated gene 608 (PAG608) as a specifically induced gene in striatal tissue of L-DOPA (100 mg/kg)-injected hemi-parkinsonian rats using differential display assay. In the present study, we further examined morphological distribution of PAG608 in the central nervous system of L-DOPA-treated hemi-parkinsonian rats. PAG608 expression was markedly induced in fibers and neuronal cells of the lateral globus pallidus and reticular thalamic nucleus adjacent to internal capsule, specifically in the parkinsonian side of L-DOPA-treated models. The protein was also constitutively expressed in motor neurons specifically in either side of the pontine nucleus and motor nuclei of trigeminal and facial nerves. Furthermore, L-DOPA-induced PAG608 expression on motor neurons in the contralateral side of the ventral horn of the spinal cord and the lateral corticospinal tract without cell loss. The specific induction of PAG608 6-48 h after L-DOPA injection in the extrapyramidal tracts, pyramidal tracts and corresponding lower motor neurons of the spinal cords suggests its involvement in molecular events in stimulated motor neurons. Taken together with the constitutive expression of PAG608 in the motor nuclei of cranial nerves, PAG608 may be a useful marker of stressed or activated lower motor neurons. © 2007 Elsevier Ireland Ltd and the Japan Neuroscience Society.

DOI： 10.1016/j.neures.2007.12.006

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：KARGER  

Background: Peritoneal fibrosis is a major complication leading to the loss of peritoneal function in patients undergoing peritoneal dialysis. However, the effect of catalase depletion on peritoneal fibrosis has not yet been investigated. Methods: The impact of catalase deficiency on progressive peritoneal fibrosis has been studied in homozygous acatalasemic mutant mice or control wild-type mice by intraperitoneal injection of chlorhexidine gluconate (CG) every other day for 14 days. Results: The CG injections resulted in a thicker peritoneal membrane, reflecting peritoneal fibrosis with accumulation of interstitial type I collagen, peritoneal deposition of lipid peroxidation products (4-hydroxy-2-nonenal and 4-hydroxy-2-hexenal), and an elevated level of 8-hydroxy-2&apos;-deoxyguanosine in peritoneal fluid in both mouse groups on day 14. The extent of these changes, however, was significantly higher in acatalasemic mice than in wild-type mice. The level of catalase activity remained low in the acatalasemic peritoneum without the compensatory upregulation of glutathione peroxidase, but with an insufficient upregulation of superoxide dismutase activity in CG-injected mice. Conclusions: Acatalasemia, therefore, exacerbates oxidant tissue injury and induces the peritoneum to develop irreversible fibrosis which is the most important complication of peritoneal dialysis. This study suggests that catalase plays a crucial role in the defense against oxidant-mediated peritoneal injury in a mouse peritoneal fibrosis model. Copyright (C) 2008 S. Karger AG, Basel.

DOI： 10.1159/000121357

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

Repeated injections of methamphetamine (METH) cause degeneration of striatal dopaminergic nerve terminals. In the present study, we examined the effects of interferon-gamma (IFN-gamma) on METH-induced striatal neurotoxicity in mice. Intraperitoneal injection of IFN-gamma before METH injection significantly prevented METH-induced reduction of striatal dopamine transporter (DAT)-positive signals and hyperthermia. Furthermore, intracerebroventricular injection of IFN-gamma before METH treatment markedly prevented METH-induced reduction of DAT. Interestingly, central IFN-gamma injection had no effect on METH-induced hyperthermia. In addition, IFN-gamma injected centrally after METH treatment, but not systemically, 1 h after the final METH injection significantly protected against METH-induced neurotoxicity. Our results suggest that IFN-gamma injected systemically or its related molecule protects against METH-induced neurotoxicity through intracerebral molecular pathways, while it can prevent METH-induced hyperthermia through different molecular events. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.toxlet.2008.01.005

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

We examined the effects of the mutual substitution of amino acid residues at positions 216 and 219 between rat CYP2D1 and CYP2D2 on their microsomal contents and enzymatic functions using a yeast cell expression system and 1-metloxy-N,N- diisopropyltryptamine (5-MeO-DIPT) as a substrate. CYP2D1 has amino acid residues, leucine and valine, at positions of 216 and 219, respectively, whereas CYP2D2 has phenylalanine and aspartic acid at the same positions. In reduced carbon monoxide-difference spectroscopic analysis, the substitution of Asp-219 of CYP2D2 by valine markedly increased a peak at 450 nm and concomitantly decreased a peak at 420 nm, while the replacement of Phe-216 of CYP2D2 with leucine gave no observable change. The double substitution of Phe-216 and Asp-219 by leucine and valine, respectively, yielded a typical CYP spectrum. The substitution of Val-219 of CYP2D1 by aspartic acid decreased the CYP content to one-half, whereas the replacement of Leu-216 with phenylalanine did not have any effect. The double substitution of Leu-216 and Val-219 of CYP2D1 by phenylalanine and aspartic acid, respectively, diminished the CYP content by 90%. CYP2D1 catalyzed both 5-MeO-DIPT N-deisopropylation and O-demethylation at relatively low levels, while CYP2D2 catalyzed 5-MeO-DIPT O-demethylation efficiently. The substitution of the amino acid at position 216 substantially increased 5-MeO-DIPT oxidation activities of the two CYP2D enzymes. The replacement of the amino acid at position 219 increased the 5-MeO-DIPT O- and N-dealkylation activities of CYP2D1, whereas it decreased the 5-MeO-DIPT O-demethylation activity of CYP2D2. These results indicate that amino acid residues at positions 216 and 219 have important roles in the enzymatic functions of rat CYPD1 and CYP2D2. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.cbi.2007.11.010

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The oxidative metabolism of 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), a tryptamine-type designer drug, was studied using rat liver microsomal fractions and recombinant cytochrome P450 (CYP) enzymes. 5-MeO-DIPT was biotransformed mainly into a side-chain N-deisopropylated metabolite and partially into an aromatic ring O-demethylated metabolite in liver microsomal fractions from untreated rats of both sexes. This metabolic profile is different from our previous findings in human liver microsomal fractions, in which the aromatic ring O-demethylation was the major pathway whereas the side-chain N-deisopropylation was minor [Narimatsu S, Yonemoto R, Saito K, Takaya K, Kumamoto T, Ishikawa T, et al. oxidative metabolism of 5-methoxy-N,N-diisopropyltryptamine (Foxy) by human liver microsomes and recombinant cytochrome P450 enzymes. Biochem Pharmacol 2006;71:1377-85]. Kinetic and inhibition studies indicated that the side-chain N-dealkylation is mediated by CYP2C11 and CYP3A2, whereas the aromatic ring O-demethylation is mediated by CYP2D2 and CYP2C6 in untreated male rats. Pretreatment of male rats with p-naphthoflavone (BNF) produced an aromatic ring 6-hydroxylated metabolite. Recombinant rat and human CYP1A1 efficiently catalyzed 5-MeO-DIPT 6-hydroxylation under the conditions used. These results provide valuable information on the metabolic fate of 5-MeO-DIPT in rats that can be used in the toxicological study of this designer drug. (c) 2007 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bcp.2007.09.019

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Language：Japanese   Publishing type：Research paper (other academic)   Publisher：Okayama Medical Association  

DOI： 10.4044/joma.119.235

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Other Link： http://ousar.lib.okayama-u.ac.jp/13216

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

The neurotoxicity of dopamine (DA) quinones as dopaminergic neuron-specific oxidative stress is considered to play a role in the pathogenesis and/or progression of Parkinson's disease (PD), since DA quinones conjugate with several key PD pathogenic molecules (e.g., tyrosine hydroxylase, alpha-synuclein and parkin) to form protein-bound quinone (quinoprotein) and consequently inhibit their functions. Zonisamide (ZNS) is used as an anti-epileptic agent but also improved the cardinal symptoms of PD in recent clinical trials in Japan. To evaluate the effects of ZNS on excess cytosolic free DA-induced quinone toxicity, we examined changes in DA quinone-related indices after ZNS treatment both in in vitro cell-free system and in cultured cells. Co-incubation of DA and ZNS in a cell-free system caused conversion of DA to stable melanin via formation of DA-semiquinone radicals and DA chrome. Long-term (5 days) treatment with ZNS decreased quinoprotein and increased DA/DOPA chromes in dopaminergic CATH.a cells. ZNS significantly inhibited quinoprotein formation induced by treatment with tetrahydrobiopterin and ketanserin that elevate cytosolic free DA in the cells. Our results suggest that the novel anti-parkinsonian agent ZNS possesses preventing effects against DA quinone formation induced by excess amount of cytosolic DA outside the synaptic vesicles. (c) 2007 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

DOI： 10.1016/j.neures.2007.10.002

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Language：Japanese  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Dopamine (DA) quinone as DA neuron-specific oxidative stress conjugates with cysteine residues in functional proteins to form quinoproteins. Here, we examined the effects of cysteine-rich metal-binding proteins, metallothionein (NIT)-1 and -2, on DA quinone-induced neurotoxicity. NIT quenched DA semiquinones in vitro. In dopaminergic cells, DA exposure increased quinoproteins and decreased cell viability; these were ameliorated by pretreatment with MT-inducer zinc. Repeated L-DOPA administration markedly elevated striatal quinoprotein levels and reduced the DA nerve terminals specifically on the lesioned side in NIT-knockout parkinsonian mice, but not in wild-type mice. Our results suggested that intrinsic NIT protects against L-DOPA-induced DA quinone neurotoxicity in parkinsonian mice by its quinone-quenching property. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.febslet.2007.09.046

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

DOI： 10.1016/j.expneurol.2007.05.006

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT) is a synthetic orally active hallucinogenic tryptamine derivative, known also as Foxy or Foxy methoxy. However, few studies have examined its effects in vitro. In the present study, we investigated the actions of 5-MeO-DIPT against monoamine neurotransmitter transporters, including the transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT), using COS-7 cells heterologously expressing these transporters and rat brain synaptosomes. 5-MeO-DIPT specifically inhibited the uptake of [H-3]serotonin (5-HT) by the SERT-expressing COS-7 cells and rat striatal synaptosomes in a high affinity manner at concentrations similar to those for cocaine. The effect was reversible and competitive. 5-MeO-DIPT failed to stimulate reverse transport of [H-3]5-HT through SERT, while it prevented the releasing action of methamphetamine. 5-MeO-DIPT induced cell toxicity at high concentrations in COS-7 cells, and it was not influenced by the expression of SERT. These results demonstrated that 5-MeO-DIPT acts as a competitive SERT inhibitor and has an inability to cause reverse transport, underlying its serotonergic actions. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.toxlet.2007.02.007

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

The p53-activated gene 608 (PAG608) is a proapoptotic gene activated and regulated by p53 expression in oxidative stress-induced apoptosis of neuronal cells. In this study, we determined the role of PAG608 in methamphetamine-induced neurotoxicity. Treatment of mouse dopaminergic CATH.a cells with 2 mM methamphetamine increased PAG608 expression at 3 h followed by increase in phosphorylated p53 expression. Transient transfection of PAG608 antisense cDNA or RNA interference using PAG608 small interfering RNA significantly attenuated the dose-dependent decrease in cell viability of CATH.a cells by methamphetamine (1-4 mM) exposure. In monoaminergic neuronal B65 cells, which contain serotonin rather than dopamine, methamphetamine-induced cell death was also significantly but partially protected by transient transfection of PAG608 antisense cDNA. Furthermore, cell death of PC 12 cells produced by methamphetamine (1-5 mM) was almost completely prevented by stable expression of PAG608 antisense cDNA, compared with significant reduction of cell viability in control PC12 cells. Our results showed that suppression of PAG608 using transient and stable transfection with PAG608 anti sense cDNA or small interfering RNA attenuates methamphetamine-induced death of various monoaminergic neuronal cells, suggesting that methamphetamine neurotoxicity in monoaminergic cells is related, at least in part, to induction of PAG608 expression. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.neulet.2006.12.036

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

Pericentrin was first identified as a mouse centrosomal protein and is now referred to as pericentrin A. A larger homologous protein in humans with a C-terminal calmodulin-binding domain was later identified as pericentrin B. Pericentrin has been shown to be one of the key components in ciliogenesis.. but in vivo pericentrin products have remained ambiguous. Here we characterized pericentrin isoforms in mice. Two pericentrin transcripts of 9.5 and 6.9 kb were recognized on the mouse tissue Northern blots, while a cRNA probe for a 5'-terminal sequence shared by pericentrin A and B failed to hybridize to the 6.9-kb message. Two pericentrin cDNAs were identified, which encoded pericentrin B and a novel isoform, pericentrin S, sharing with pericentrin B a C-terminal calmodulin-binding motif. Three pericentrin proteins of 360, 255, and 250 kDa revealed by immunoprecipitation analysis were thought to correspond to pericentrin B, pericentrin S, and an unknown N-terminal product. (c) 2006 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2006.10.101

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

We examined the involvement of the signal transducer and activator of transcription 3 (STAT3) in bladder outlet obstruction (BOO)-induced bladder smooth muscle hypertrophy using a rat in vivo and in vitro study. BOO induced increases in bladder weight and bladder smooth muscle thickness I week after the operation. By using antibody microarrays, 64 of 389 proteins blotted on the array met our selection criteria of an INR value between &gt;= 2.0 and &lt;= 0.5. This result revealed up-regulation of transcription factors, cell cycle regulatory proteins, apoptosis-associated proteins and so on. On the other hand, down-regulation (INR value &lt;= 0.5) of proteins was not found. In a profiling study, we found an increase in the expression of STAT3. A significant increase in nuclear phosphorylated STAT3 expression was confirmed in bladder smooth muscle tissue by immunohistochemistry and Western blot analysis. Cyclical stretch-relaxation (I Hz) at 120% elongation significantly increased the expression of STAT3 and of alpha-smooth muscle actin in primary cultured bladder smooth muscle cells. Furthermore, the blockade of STAT3 expression by the transfection of STAT3 small interfering RNA (siRNA) significantly prevented the stretch-induced increase in alpha-smooth muscle actin expression. These results suggest that STAT3 has an important role in the induction of bladder smooth muscle hypertrophy.

DOI： 10.18926/AMO/30724

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

To clarify the possible role of in the in vivo toxic effects of 6-hydroxydopamine (6-OHDA), especially caspase activations, we examined its effects on striatal lipid peroxidation (LPO) and caspase activations in 6-OHDA-lesioned mice. Both dopamine (DA) levels and DA turnover were significantly changed by the 6-OHDA i.c.v. injection compared with the pre-injection level in the striatum. In addition, the striatal glutathione (GSH) content fluctuated and was significantly decreased both at 3 and 14 days after 6-OHDA i.e.v. injection. Moreover, superoxide dismutase (SOD) activity at 7 days after 6-OHDA i.c.v. injection was transiently and significantly increased compared with the pre-injection level. The levels of thiobarbituric acid-reactive substances (TBA-RS) were significantly increased at 1, 3 and 14 days. 6-OHDA significantly increased the activities of all three caspases, except for the caspase-3 activity at 7 days throughout the experimental period compared with the pre-injection level. In conclusion, 6-OHDA-induced dopaminergic dysfunction is mainly due to caspase activations by increases in oxidative stress in the mouse striatum. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.neulet.2006.08.021

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Authorship：Lead author,　Corresponding author   Language：English   Publisher：EXPERT REVIEWS  

It has been revealed that nonsteroidal anti-inflammatory drugs (NSAIDs) have neuroprotective properties based not only on their cyclooxygenase-inhibitory action, but also on other properties including their inhibitory effects on the synthesis of nitric oxide radicals and agonistic action for peroxisome proliferator-activated receptor gamma, in addition to some as yet unknown properties. Recently, a number of experimental and clinical studies have examined the neuroprotective effects of NSAIDs on the pathogenesis of several neurodegenerative diseases, including Parkinson's disease. In this article, various pharmacological effects of NSAIDs (except for their cyclooxygenase-inhibitory action) are reviewed, and possible neuroprotective effects of NSAIDs on Parkinson's disease are discussed. The neurotoxicity of dopamine quinones, or DOPA quinones, has recently received attention as a dopaminergic neuron-specific oxidative stress that is known to play a role in the pathogenesis of Parkinson's disease and neurotoxin-induced parkinsonism. NSAIDs inhibit prostaglandin H synthase, thus suppressing dopamine oxidation and subsequent dopamine quinone formation. Therefore, this article also reviews possible suppressive effects of some NSAIDs against dopamine quinone generation. Expert Rev. Neurotherapeutics 6(9), 1313-1325 (2006)

DOI： 10.1586/14737175.6.9.1313

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Pericentrin (Pcnt) is a giant coiled-coil protein known to mediate microtubule organization. It has been recently reported that mitosis-specific centrosomal anchoring of gamma tubulin complexes by Pcnt acts to control mitotic spindle organization, though little is known about the in vivo expression of Pcnt. In this study, we investigated Pcnt expression in mouse embryos. In situ hybridization analysis revealed preferential expression of Pcnt in quiescent G(0) phase cells throughout the embryo with an unexpectedly low expression level in proliferating cells, suggesting that Pcnt might not play an important role in mitotic proliferation. Immunofluorescence analysis confirmed preferential expression of the Pcnt protein in G(0) phase cells. Moreover, Pcnt was shown to be localized to the base of primary cilia in multiple embryonic tissues, in agreement with a recent study demonstrating the involvement of Pcnt in primary cilia formation using cultured mammalian cells.

DOI： 10.1007/s00427-006-0065-8

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.bcp.2006.01.015

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Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1096/fj.05-4996fje

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1096/fj.05-4996fje

Language：Japanese   Publishing type：Research paper (other academic)  

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Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s00415-005-4006-7

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Other Link： http://link.springer.com/article/10.1007/s00415-005-4006-7/fulltext.html

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ovid Technologies (Wolters Kluwer Health)  

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<italic>Background—</italic>
</bold>
Idiopathic pulmonary arterial hypertension (IPAH) is associated with proliferation of smooth muscle cells (SMCs) in small pulmonary arteries. There is no therapy that specifically inhibits SMC proliferation. Recent studies reported that prednisolone (PSL) inhibits the postangioplasty proliferation of SMCs in atherosclerotic arteries. In this study, we tested the hypothesis that PSL has antiproliferative effects on pulmonary artery SMCs of patients with IPAH.




<bold>
<italic>Methods and Results—</italic>
</bold>
Pulmonary artery SMCs were harvested from the pulmonary arteries of 6 patients with IPAH who underwent lung transplantation. Control SMCs were obtained from 5 patients with bronchogenic carcinoma who underwent lung lobectomy. After incubation in the presence of platelet-derived growth factor (PDGF), PSL was added at different concentrations and cell proliferation was assessed by
³
H-thymidine incorporation. PSL (2×10
⁻⁴
and 2×10
⁻³
mol/L) significantly inhibited PDGF-stimulated proliferation (
<italic>P</italic>
&lt;0.05) of SMCs from patients with IPAH but did not affect cell viability of SMCs, as confirmed by trypan blue staining. In cell cycle analysis using a microscope-based multiparameter laser scanning cytometer, PSL inhibited the progression of SMCs from G
₀
/G
₁
to the S phase. This inhibition was associated with increased p27 expression level. PSL (2×10
⁻⁴
mol/L) also inhibited PDGF-induced SMC migration.




<bold>
<italic>Conclusions—</italic>
</bold>
Our results indicate that PSL has an antiproliferative effect on cultured SMCs of pulmonary arteries from patients with IPAH and suggest that PSL may be potentially useful therapeutically in patients with IPAH.

DOI： 10.1161/circulationaha.105.536169

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The neurotoxicity of dopamine (DA) quinones that appears in dopaminergic neuron-specific oxidative stress has recently been shown to play a role in the pathogenesis and/or progression of Parkinson disease. To clarify the effects of a DA agonist, pergolide, on the levodopa-induced elevation of quinones, the authors examined, striatal changes in quinoprotein using a hemi-parkinsonian mouse model. The level of striatal quinoprotein was significantly elevated specifically on the parkinsonian side, but not on the control side, after repeated levodopa administration. This levodopa-induced increase in striatal quinoprotein was almost completely suppressed by adjunctive administration with pergolide on the lesioned side. Furthermore, it was clarified that pergolide scavenged DA-semiquinones generated in vitro in a dose-dependent manner. These suppressive and quenching effects of pergolide against cytotoxic DA quinones may play a key role in its neuroprotective mechanism in the parkinsonian brain. Copyright © 2005 by Lippincott Williams &amp
Wilkins.

DOI： 10.1097/01.wnf.0000175523.33334.24

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japanese Pharmacological Society  

DOI： 10.1254/fpj.126.30

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Maney Publishing  

DOI： 10.1179/016164105x22093

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DOI： 10.1016/j.bbrc.2005.04.124

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DOI： 10.1016/j.neuroscience.2005.01.044

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Expression of dopamine receptors (DA-Rs) in astrocytes was examined in vitro and in vivo using primary cultured astrocytes and brain slices from rat basal ganglia. Astrocytes from basal ganglia expressed DA D1-, D3-, D4- and D5-receptors and D4-mediated signal transduction in response to DA, suggesting possible involvement of astrocytes in the pharmacological action of atypical antipsychotic drugs and in DA response in some neurological diseases. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.brainres.2004.09.014

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Authorship：Lead author,　Corresponding author   Language：English   Publisher：Okayama University Medical School  

DOI： 10.18926/AMO/32105

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DOI： 10.1196/annals.1316.009

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DOI： 10.1179/016164104225015895

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

A symposium on the clinical aspects of metallothioneins (MTs) in neurodegenerative diseases was held at the 2003 Society of Metallothionein Meeting in Gifu, Japan. The objectives of the symposium were to review and speculate on the potential roles of MTs, especially MT-3 in neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and spinocerebellar degeneration (SCD). Dr. Uchida discussed the controversial problem regarding the expression of MT-3 in AD brains. Dr. Asanuma addressed the function of MTs in the progression of PD and Dr. Hozumi described the therapeutic potential of MTs for ALS, while Dr. Yamada provided immunohistochemical findings of MT-3 in SCD for the first time. Although there are still controversial problems on MTs, this review provides proof that MTs are promising potential therapeutic targets for therapy for some neurodegenerative diseases.

DOI： 10.1248/jhs.50.323

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DOI： 10.1023/b:nere.0000029565.92587.25

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DOI： 10.1111/j.1471-4159.2004.02445.x

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DOI： 10.1016/j.bbrc.2004.03.163

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DOI： 10.2174/1381612043453072

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DOI： 10.1016/j.neulet.2003.09.059

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：(一社)日本不整脈心電学会  

欧米における大規模臨床試験の結果は,β遮断薬が慢性心不全の生命予後改善のみならず,突然死も有意に抑制することを明らかにした.しかし,患者背景の異なる我が国における,β遮断薬の有効性は必ずしも明確ではない.そこで,著者等の自験例を基に,致死性不整脈患者或いは慢性心不全患者に対するカルベジロールを中心としたβ遮断薬の予後に対する影響及び突然死予防効果,その機序について検討した

DOI： 10.5105/jse.24.15

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Oxidative stress is known to contribute to numerous cardiac disease processes. However, the contribution of reactive oxygen species to cardiac hypertrophy has not yet been fully investigated. The aim of the present study was therefore to determine whether levels of reactive oxygen species were increased in angiotensin II-induced cardiac hypertrophy. We continuously administered angiotensin II (1.1 mg/kg per day) into wild-type and angiotensin II type-1a receptor knockout mice for 2 weeks. The angiotensin II treatment increased blood pressure and heart weight/body weight ratio in wild-type mice but not in knockout mice. The generation of hydroxyl radicals in heart tissue homogenate was directly assessed with electron spin resonance spectroscopy using a spin trapping agent, alpha-phenyl-N-tert butylnitrone. Angiotensin II significantly increased hydroxyl radical production 2.2-fold (p < 0.01) in the hearts of wildtype mice but not in knockout mice. The present study provided direct evidence for increased production of hydroxyl radicals in angiotensin II-induced cardiac hypertrophy through angiotensin II type-1a receptor. These findings in this study may provide important insights into the development of hypertrophy and the transition of hypertrophy to heart failure.

DOI： 10.1097/00005344-200312001-00015

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DOI： 10.1016/j.neulet.2003.08.015

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DOI： 10.1016/s0168-0102(03)00166-4

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DOI： 10.1007/bf03033137

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Other Link： http://link.springer.com/article/10.1007/BF03033137/fulltext.html

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DOI： 10.1016/s0304-4165(02)00440-3

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DOI： 10.1074/jbc.m203594200

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人日本薬学会  

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DOI： 10.1016/s0168-0102(02)00057-3

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DOI： 10.1016/s0304-3940(02)00346-4

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DOI： 10.1016/s0168-0102(02)00040-8

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DOI： 10.1016/s0304-3940(02)00291-4

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DOI： 10.1046/j.1471-4159.2001.00205.x

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DOI： 10.1002/1098-2396(20010315)39:4<305::aid-syn1013>3.0.co;2-e

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/s0168-0102(00)00233-9

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Okayama University Medical School  

DOI： 10.18926/AMO/32031

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DOI： 10.1023/a:1007672414239

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Okayama University Medical School  

DOI： 10.18926/AMO/32278

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DOI： 10.1016/s0304-3940(00)01488-9

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DOI： 10.1046/j.1471-4159.2000.0751771.x

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DOI： 10.1016/s0169-328x(00)00128-5

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DOI： 10.1023/a:1007530720544

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DOI： 10.1016/s0006-8993(99)02284-2

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DOI： 10.1023/a:1007515318434

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DOI： 10.1023/a:1020953913490

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DOI： 10.1046/j.1471-4159.1999.0722334.x

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DOI： 10.1023/a:1021044107323

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：医学書院  

DOI： 10.11477/mf.1431901046

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Other Link： http://search.jamas.or.jp/link/ui/1999175489

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DOI： 10.1023/a:1020915727119

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DOI： 10.11477/mf.2425901650

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DOI： 10.1016/s0165-0270(98)00092-2

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DOI： 10.1002/(sici)1098-2396(199810)30:2<150::aid-syn4>3.0.co;2-b

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DOI： 10.1016/s0169-328x(98)00188-0

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DOI： 10.1016/s0304-3940(98)00489-3

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DOI： 10.1016/s0169-328x(98)00055-2

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DOI： 10.1016/s0006-8993(97)01521-7

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DOI： 10.1016/s0306-4522(97)00665-9

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DOI： 10.1023/a:1022475830587

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DOI： 10.1016/s0168-0102(97)00128-4

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DOI： 10.1007/978-3-7091-6475-4_42

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DOI： 10.1111/j.1440-1819.1997.tb02610.x

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Publishing type：Research paper (scientific journal)   Publisher：Mary Ann Liebert Inc  

DOI： 10.1089/neu.1997.14.739

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DOI： 10.1016/s0169-328x(97)00190-3

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DOI： 10.1016/s0006-8993(97)00836-6

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DOI： 10.1016/s0006-8993(97)00330-2

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DOI： 10.1016/s0167-0115(97)01013-6

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DOI： 10.1002/art.1780400520

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DOI： 10.1016/s0304-3940(97)00204-8

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DOI： 10.1023/a:1027369119224

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN BRAIN SCI SOC  

Late-onset reduction of muscarinic acetylcholine receptors (LORMAR) in the ischemic gerbil hippocampus begins as late as 7 days after a 5-min transient forebrain ischemia and reperfusion. We previously reported that LORMAR is prevented by postadministration of cyclosporin A. In the present study, we aim to elucidate whether the LORMAR can also be prevented by post-ischemic administration of the immunosuppressant FK506 (tacrolimus). We investigated changes in muscarinic acetylcholine receptor binding capacity and histological examination in the transient forebrain ischemic gerbil hippocampus and the effect of this agent on these changes. In the ischemic vehicle-treated group, muscarinic acetylcholine receptors significantly decreased in the hippocampus as the LORMAR with subsequent disruption of the pyramidal cells in the CA1 area. On the other hand, LORMAR is prevented by daily subcutaneous administration of low dose of FK506 (0.5 mg/kg/day) for 10 days after the ischemic insult, although delayed neuronal cell death was not prevented. Thus, we showed that the LORMAR is attenuated by post-administration of FK506.

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DOI： 10.1007/978-3-7091-6837-0_56

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DOI： 10.1046/j.1471-4159.1996.67052208.x

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DOI： 10.1016/0169-328x(96)00098-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The effects of chronic hypoperfusion of cerebral blood flow (CBF) on central cholinergic indices and intellectual functions were investigated in rats. Male Wistar rats, aged 9 weeks, were anesthetized with pentobarbital, and the bilateral common carotid arteries were permanently ligated. Cortical CBF in the hypoperfused rats was markedly decreased at 6 weeks after the operation. In the hypoperfused group, cholinergic indices were changed to consist two phases after the operation, before (acute) and after (chronic) 6 weeks after the operation. At 6 weeks, choline acetyltransferase activity was restored to the sham-operated level compared with the changes in the frontal cortex and thalamus + midbrain at 3 weeks. On the other hand, the maximum number of muscarinic acetylcholine receptors was reduced in the frontal cortex, hippocampus and striatum at 6 weeks and thereafter remained at this low level. In discrimination learning task, the percentage of correct responses in the hypoperfused rats was generally reduced in contrast with that of the sham-operated rats, although the number of total responses were not changed. As a consequence, cholinergic dysfunctions correlate with discrimination learning disabilities in the hypoperfused rats. These findings suggest that the hypoperfused rat may be useful for the cerebrovascular type dementia model to clarify pathophysiology.

DOI： 10.1016/S0006-8993(96)00400-3

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Bromocriptine, a dopamine agonist, alleviates symptoms of Parkinson's disease, even when administered alone, and is used for its treatment. Better therapeutic effects are, however, achieved when bromocriptine is used in combination with levodopa. In this study, we examined the biochemical changes caused by bromocriptine administration with and without levodopa, and evaluated the effects of the treatments on dopamine turnover in the mouse striatum. Results show that dopamine turnover is suppressed by the administration of bromocriptine alone with a slight decrease in the amount of dopamine, and dopamine turnover is very strongly promoted by the administration of levodopa. When the two drugs are administered together, bromocriptine enhances the levodopa-induced increase in dopamine turnover in the striatum. These findings indicate that bromocriptine therapy in combination with levodopa enhances the dopaminergic function and suggest that the combination therapy of bromocriptine and levodopa shows good efficacy. The results of this study may, thus, provide a theoretical basis for the combination therapy of bromocriptine and levodopa.

DOI： 10.1177/030006059602400306

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In a cultured hybrid neuronal cell line (BIM) which was produced between human neuroblastoma cells (IMR32) and thymidine auxotrophs (B3T) of rat nerve-like cells (B103), the mRNAs encoding ciliary neurotrophic factor (CNTF) and neurotrophins were detected by the polymerase chain reaction method. The conditioned medium of BIM cells enhanced choline acetyltransferase (ChAT) activity in septal neurons and survival of-ciliary ganglion neurons. The mRNA expression of CNTF and neurotrophins in BIM cells was differently regulated by the stimulation with cAMP, FGF and retinoic acid. These data suggest multiple regulation and collaboration of neurotrophic factors.

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DOI： 10.1016/0168-0102(95)01017-3

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DOI： 10.1016/0006-8993(95)01446-2

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DOI： 10.1016/0304-3940(95)12152-8

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Our objective was to clarify the DNA-binding activity of transcription factor NF-kappa B as related to cytokine induction in the synovium of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Synovial membranes were obtained during arthroplasty of the knee from 7 patients with RA and 4 patients with OA. Nuclear extracts obtained from the synovial membranes were examined by electrophoretic mobility shift assay to determine the DNA-binding activity of NF-kappa B. Markedly high DNA-binding activity of NF-kappa B was detected in the synovial membranes of RA patients, while virtually no activity was observed in those of OA patients. These results suggest that the high induction of NF-kappa B in the nuclear extracts may be relatively specific to synovial membranes in RA. NF-kappa B may regulate the production of cytokines at the site of synovial inflammation.

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DOI： 10.1016/0169-328x(95)00102-x

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<italic>Background and Purpose</italic>
Hypertension is a primary aggravating factor in cerebral infarction. An acute rise in blood pressure (BP) at the time of a stroke may be harmful to the brain in a hypertensive subject because both cerebral vascular structure and function are altered by hypertension. Muscarinic M
₁
receptors are concerned with memory and learning. We aimed to evaluate the effect of controlling BP in hypertensive subjects at the time of stroke with a biochemical index of brain damage.




<italic>Methods</italic>
We gave a single dose of either the antihypertensive α-blocker phentolamine (2 mg/kg IP) or the calcium antagonist nicardipine (2 mg/kg IP) at the start of bilateral carotid artery occlusion to spontaneously hypertensive rats undergoing 3 hours of transient ischemia; we measured the time course of mean BP (MBP) and changes in the M
₁
receptor and its mRNA in three brain regions 2 weeks after the transient ischemia.




<italic>Results</italic>
Administration of phentolamine or nicardipine not only significantly suppressed the ischemia-induced rise of MBP, it actually decreased MBP during ischemia. In an ischemic control group, M
₁
receptor binding decreased in the frontal cortex and M
₁
receptor mRNA increased in the hippocampus 2 weeks after the ischemia. In contrast, both phentolamine- and nicardipine-treated ischemic rats showed no changes in either index compared with sham-operated controls.




<italic>Conclusions</italic>
Controlling BP during an ischemic insult attenuates ischemia-induced damage of M
₁
receptors in the brain of spontaneously hypertensive rats. These results suggest that a rapid intensive increase of BP at the time of a stroke may exacerbate brain damage in hypertensive individuals.

DOI： 10.1161/01.str.26.7.1268

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To clarify the effects of levodopa administration on MPTP-induced alterations in neuropeptides, we examined the effects of repeated levodopa injections (200 mg/kg i.p.) for 2 weeks starting 4 weeks after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment (30 mg/kg i.p. twice/day for 5 days) on cholecystokinin-octapeptide (CCK-8), substance P (SP) and thyrotropin-releasing hormone (TRH) concentrations at 6 weeks after the MPTP treatment. In the striatum, CCK-8 significantly but slightly decreased in the MPTP-treated mice, coinciding with the MPTP-induced marked reduction of dopamine (DA). This considerable reduction of striatal CCK-8 may result from the selectivity of MPTP since the mesolimbic DA neurons coexisting with CCK-8 are intact with the MPTP treatment. Furthermore, this MPTP-induced decrease in CCK-8 persisted with repeated levodopa administration; therefore, the ineffectiveness of the levodopa treatment may have been be due to the degeneration of the nigrostriatal DA neurons. SP and TRH contents showed little or no change with levodopa treatment in the MPTP-treated mouse brain. The CCK-8 level decreased in the thalamus+midbrain, hippocampus and hindbrain of the MPTP + levodopa-treated group, although there were no changes in the MPTP-treated controls. These results suggest that DAergic neurons, except those in the nigrostriatum, strongly interact with the CCK neurons in these brain regions.

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ARCH INT PHARMACODYNAMIE  

Pergolide, along with bromocriptine and lisuride, is one of the most active dopamine receptor agonists. To determine whether or not pergolide protects against dopaminergic neuronal damage, via its activity on monoamine metabolism, we studied the effects of pergolide pretreatment on changes in monoamines and their metabolites in the mouse striatum after intracerebroventricular injection of 6-hydroxydopamine with pretreatment of desipramine. After intracerebroventricular administration of 6-hydroxydopamine (40 mu g) in mice, the levels of dopamine and its metabolites (DOPAC, HVA) in the striatum rapidly decreased to 49%, 29% and 68%, respectively, of the naive controls at week 1 but then gradually recovered to control levels at weeks 2 and 4. Repeated pretreatment with pergolide (0.5 mg/kg, i.p.) for 7 days before administration of 6-hydroxydopamine, almost completely protected against reduction in striatal dopamine and its metabolites 1 week after injection of 6-hydroxydopamine. Therefore, pergolide could normalize the decreased dopamine synthesis or storage, and has a neuroprotective effect against dopaminergic dysfunction induced by the neurotoxin, 6-hydroxydopamine. Although we found that pergolide did not show radical scavenging activity in an in vitro system that generated hydroxyl radicals, it has been reported in vivo that pergolide treatment may induce Cu/Zn superoxide dismutase in the rat striatum. Considering these findings, pergolide may well be protective to dopaminergic neurons, largely because of its effects on presynaptic autoreceptors and on its induction of Cu/Zn superoxide dismutase. Further research on the neuroprotective effects of pergolide in Parkinson disease models, by injection of 6-hydroxydopamine, is needed to clarify its mechanism of action on dopaminergic indices.

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/0168-0102(95)00878-w

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Publishing type：Research paper (scientific journal)   Publisher：SAGE Publications  

With use of iron histochemistry and immuno-histochemistry, regional changes in the appearance of iron, ferritin, transferrin, glial fibrillary acidic protein–positive astrocytes, and activated microglia were examined from 1 to 24 weeks after transient forebrain ischemia (four-vessel occlusion model) in rat brain. Expression of the C3bi receptor and the major histocompatibility complex class II antigen was used to identify microglia. Neuronal death was confirmed by hematoxylin–eosin staining only in pyramidal cells of the hippocampal CA, region, which is known as the area most vulnerable to ischemia. Perls' reaction with 3,3′-diaminobenzidine intensification revealed iron deposits in the CA, region after week 4, which gradually increased and formed clusters by week 24. Iron also deposited in layers III-V of the parietal cortex after week 8 and gradually built up as granular deposits in the cytoplasm of pyramidal cells in frontocortical layer V. An increasing astroglial reaction and the appearance of ferritin-immunopositive microglia paralleled the iron accumulation in the hippocampal CA, region, indicating that iron deposition was probably produced in the process of gliosis. Neither neuronal death nor atrophy was found in the cerebral cortex. Nevertheless, an astroglial and ferritin-immunopositive microglial reaction became evident at week 8 in the parietal cortex. On the other hand, the granular iron deposition in the pyramidal neurons of frontocortical layer V was not accompanied by any glial reaction in the chronic stage of ischemia. Three different types of iron deposition in the chronic phase after transient forebrain ischemia were shown in this study. In view of the neuronal damage caused by iron-catalyzed free radical formation, the late-onset iron deposition may be relevant to the pathogenesis of the chronic brain dysfunction seen at a late stage after cerebral ischemia.

DOI： 10.1038/jcbfm.1995.27

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：S. Karger AG  

DOI： 10.1159/000173903

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/0167-0115(94)00105-7

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/bf00995159

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Other Link： http://link.springer.com/article/10.1007/BF00995159/fulltext.html

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

Using the 3-hr common carotid occlusion model in spontaneously hypertensive rats (SHRs), we investigated the changes in monoamines and their metabolites up to the chronic phase, 6 mouths after the transient forebrain ischemia, in various brain regions. In the striatum, the levels of dopamine (DA) at the 3rd week and serotonin (5-HT) at the 2nd week were 1.6-fold and 2.4-fold higher than the levels in the respective sham-operated controls coinciding with increases in their metabolites, homovanillic acid and 5-hydroxyindoleacetic acid. However, these marked increases in both transmitters were transient aid their levels recovered to the sham-operated levels. This transient increase in DA release in the striatum may be caused by ischemia-induced disruption of nerve endings, and may aggravate tissue damage in the striatum at the chronic phase after ischemia. Transient or lasting changes in noradrenaline, DA, 5-HT and their metabolites were also observed in other brain regions, the thalamus+midbrain and the hippocampus of SHRs after transient ischemia. These ischemia-induced alterations in monoamines at the chronic phase may be partly involved in the late-onset sequelae seen in the cerebrovascular disorders.

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Regional changes in the mRNA accumulations for cytoskeletal proteins alpha-tubulin and beta-actin were examined by in situ hybridization and Northern blot analysis in spontaneously hypertensive rat brains at chronic stages after 3 hours of transient ischemia. alpha-Tubulin mRNA accumulations showed no significant change at 2 weeks after transient ischemia except for a significant decrease in the frontal cortex (9.7%, p &lt; 0.01) coinciding with ischemia induced histological changes. beta-Actin mRNA level was significantly increased in the parietal cortex (8.5%), septum (10.0%), amygdala (11.0%), CA4 area (5.8%) and the dentate gyrus (7.5%) of the hippocampus at 2 weeks after recirculation compared with a sham-operated control group (p&lt;0.01). The ischemic areas of hippocampal and frontocortical lesions receive afferent neurons from those regions where beta-actin mRNA was increased, suggesting that ischemia-induced increases in beta-actin mRNA may reflect actin synthesis in these neurons to compensate for lost synaptic connections. Two cytoskeletal mRNA concentrations reacted differently to cerebral ischemia, and did not parallel histological signs of ischemia either temporally or spatially.

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/0167-4943(94)00572-9

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DOI： 10.1016/0197-4580(94)90054-x

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DOI： 10.1016/0006-8993(94)90969-5

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DOI： 10.1016/s0006-8993(09)90013-0

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/j.1440-1819.1994.tb03068.x

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/0006-8993(94)90102-3

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DOI： 10.1016/0304-3940(94)90603-3

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Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/bf00966804

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Walter de Gruyter GmbH  

DOI： 10.1515/revneuro.1994.5.2.171

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/0006-8993(94)91536-9

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：P J D PUBLICATIONS LTD  

To determine ischemia-induced changes in phosphodiesterase (PDE), changes in the membranous binding sites of rolipram, a cAMP-selective PDE inhibitor, were examined in the gerbil brain following transient 5 min forebrain ischemia. Coinciding with the delayed neuronal death (DND) in the hippocampal CA1 region, affinities for cerebral rolipram bindings decreased on Day 4, when intrinsic cAMP, substrate for PDE, might increase. The number of rolipram binding sites was significantly reduced in the hippocampus on Day 14, despite the lack of change on Day 4. This reduction in rolipram binding was in agreement with the previously reported late onset reduction of muscarinic receptors, progressing more slowly than DND. Slowly progressive mechanisms may be involved in the ischemia-induced reduction of the hippocampal rolipram binding sites which may be PDEs

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/0167-4943(93)90040-o

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DOI： 10.1016/0169-328x(93)90028-n

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DOI： 10.1007/bf01244874

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ARCH INT PHARMACODYNAMIE  

The effects of a new acetylcholinesterase inhibitor, ENA-713, on ischemia-induced changes in acetylcholine, monoamines, and their metabolites, were studied in the gerbil. ENA-713 (0.2 mg/kg) or saline was administered intraperitoneally to gerbils 30 min before induction of cerebral ischemia by bilateral carotid occlusion. Pretreatment with ENA-713 mitigated the ischemia-induced abnormalities of the cholinergic, dopaminergic and serotoninergic systems in the gerbil brain, although it had virtually no effect on acetylcholine, monoamines, or their metabolites in any region of the normal gerbil brain. These findings suggest that ENA-713 has beneficial effects against ischemia-induced cerebral disorders. Thus, ENA-713 seems to be promising as a preventive or therapeutic agent for cerebrovascular dementia due to cerebral ischemia and might be useful for the treatment of Alzheimer-type dementia which is associated with multiple neurotransmitter abnormalities in the brain.

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DOI： 10.1016/0304-3940(93)90511-i

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