Faculty Profiles - OKAMURA Hirohiko

Papers - OKAMURA Hirohiko

Division display 41 - 60 of about 113 ／ All the affair displays >>

Inhibitory effect of retinoic acid receptor agonists on in vitro chondrogenic differentiation. Reviewed

Sumitani Y, Uchibe K, Yoshida K, Weng Y, Guo J, Yuan H, Ikegame M, Kamioka H, Okamura H

Anatomical Science International 2019

Porphyromonas gingivalis感染したマクロファージが産生する膜小胞が肝臓糖代謝に及ぼす影響 Reviewed

吉田賀弥, 藤原奈津美, 尾崎和美, 内部健太, 池亀美華, 岡村裕彦

Journal of Oral Biosciences Supplement 2018 153 - 153 2018.9

Expression of Noncollagenous Bone Matrix Proteins in Osteoblasts Stimulated by Mechanical Stretching in the Cranial Suture of Neonatal Mice. Reviewed

Ikegame M, Ejiri S, Okamura H

The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society 22155418793588 2018.8

Reduction of protein phosphatase 2A Cα promotes in vivo bone formation and adipocyte differentiation. Reviewed International journal

Kaya Yoshida, Jumpei Teramachi, Kenta Uchibe, Mika Ikegame, Lihong Qiu, Di Yang, Hirohiko Okamura

Molecular and cellular endocrinology 470 251 - 258 2018.7

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

Serine/threonine protein phosphatase 2A (PP2A) regulates diverse physiological processes such as cell cycle, growth, apoptosis, and signal transduction. Previously, we demonstrated that silencing of the α-isoform of PP2A catalytic subunit (PP2A Cα) in osteoblasts accelerated osteoblast differentiation, whereas its overexpression suppressed differentiation. In this study, we examined the role of PP2A Cα in in vivo bone formation by generating transgenic mice (PP2A-Tg), in which the dominant negative form of PP2A Cα was specifically expressed in osteoblasts. PP2A-Tg mice exhibited an increase in body weight, cortical bone mineral density, and cortical bone thickness. Interestingly, they also displayed higher amounts of adipose tissue in the bone marrow of tibiae. The co-culture study showed that PP2A Cα-knockdown osteoblasts stimulated adipocyte differentiation from undifferentiated mesenchymal cells via upregulation of the adipocyte marker genes, such as peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα). These results indicated that the reduction of PP2A Cα levels in osteoblasts promoted bone formation in vivo. Additionally, PP2A Cα in osteoblasts was also potentially involved in controlling adipocyte differentiation through a paracrine mechanism.

DOI： 10.1016/j.mce.2017.11.005

Upregulated osterix expression elicited by Runx2 and Dlx5 is required for the accelerated osteoblast differentiation in PP2A Cα-knockdown cells Reviewed

Di Yang, Hirohiko Okamura, Lihong Qiu

Cell Biology International 42 ( 4 ) 403 - 410 2018.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley-Blackwell Publishing Ltd

Serine/threonine protein phosphatase 2A (PP2A) is involved in regulating various physiological processes including cell cycle, growth, apoptosis, and signal transduction. Osteoblast differentiation is controlled by main bone specific transcription factors including Osterix, distal-less homeobox 5 (Dlx5), and Runt-related transcription factor 2 (Runx2). We previously reported that knockdown of PP2A Cα increases the expression of Osterix, leading to the accelerated osteoblast differentiation through the upregulation of bone-related genes. In this study, we examined whether Dlx5 and Runx2 are involved in the upregulated Osterix expression in PP2A Cα-knockdown osteoblasts (shPP2A cells). The expression of Dlx5 as well as Osterix was significantly higher in shPP2A cells in the initial stage of osteoblast differentiation compared with the control cells (shCont). The expression of Runx2 protein was also higher in shPP2A cells compared with shCont cells although its mRNA level was comparable. Reduction of Dlx5 or Runx2 decreased Osterix expression and alkaline phosphatase activity in shPP2A cells. Luciferase assay showed that Osterix promoter activity was drastically elevated in shPP2A cells compared with that in shCont cells. The deletion or mutation of the Dlx5 and Runx2 binding sites significantly suppressed Osterix promoter activity in shPP2A cells. These results indicate that Dlx5 and Runx2 are critical factors for the upregulated Osterix expression in shPP2A cells, which is considered to be important for the accelerated osteoblast differentiation in these cells.

DOI： 10.1002/cbin.10902

Organoids with cancer stem cell-like properties secrete exosomes and HSP90 in a 3D nanoenvironment Reviewed

Takanori Eguchi, Chiharu Sogawa, Yuka Okusha, Kenta Uchibe, Ryosuke Iinuma, Kisho Ono, Keisuke Nakano, Jun Murakami, Manabu Itoh, Kazuya Arai, Toshifumi Fujiwara, Yuri Namba, Yoshiki Murata, Kazumi Ohyama, Manami Shimomura, Hirohiko Okamura, Masaharu Takigawa, Tetsuya Nakatsura, Ken-ichi Kozaki, Kuniaki Okamoto, Stuart K. Calderwood

PLoS ONE 13 ( 2 ) e0191109 2018.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Public Library of Science

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression.

DOI： 10.1371/journal.pone.0191109

多彩な役割をもつ蛋白質脱リン酸化酵素PP2A Invited Reviewed

岡村裕彦

岡山歯学会雑誌 36 ( 2 ) 25 - 36 2018

PKR induces the expression of NLRP3 by regulating the NF-κB pathway in Porphyromonas gingivalis-infected osteoblasts Reviewed

Kaya Yoshida, Hirohiko Okamura, Yuka Hiroshima, Kaori Abe, Jun-ichi Kido, Yasuo Shinohara, Kazumi Ozaki

Experimental Cell Research Vol.354 ( No.1 ) 57 - 64 2017.5

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

The double-stranded RNA-dependent kinase (PKR), which is activated by double stranded RNA, induces inflammation by regulating NF-κB signaling. The NLR family pyrin domain-containing 3 (NLRP3) inflammasome also modulates inflammation in response to infection. Porphyromonas gingivalis (P.gingivalis) is an oral bacterium which is implicated in the pathogenesis of periodontal diseases. We previously reported that PKR is a key modulator of bone metabolism and inflammation in the periodontal tissue. PKR was also reported to induce inflammation in response to microbes by regulating the NLRP3 inflammasome, suggesting that PKR could affect inflammation along with NLRP3 in periodontal diseases. In this study, we investigated the effects of PKR on NLRP3 expression and NF-κB activity in P. gingivalis infected osteoblasts. We first constructed a SNAP26b-tagged P.gingivalis (SNAP-P. g.) and traced its internalization into the cell. SNAP-P. g. increased the activity of PKR and NF-κB and also induced NLRP3 expression in osteoblasts. Inhibition of NF-κB attenuated SNAP-P. g.-induced NLRP3 expression. The knockdown of PKR using shRNA decreased both the activity of NF-κB and the expression of NLRP3 induced by SNAP-P.g.. We therefore concluded that in osteoblasts, P. gingivalis activated PKR, which in turn increased NLRP3 expression by activating NF-κB. Our results suggest that PKR modulates inflammation by regulating the expression of the NLRP3 inflammasome through the NF-κB pathway in periodontal diseases.

DOI： 10.1016/j.yexcr.2017.03.028

PKR induces the expression of NLRP3 by regulating the NF-kappa B pathway in Porphyromonas gingivalis-infected osteoblasts Reviewed

Kaya Yoshida, Hirohiko Okamura, Yuka Hiroshima, Kaori Abe, Jun-ichi Kido, Yasuo Shinohara, Kazumi Ozaki

EXPERIMENTAL CELL RESEARCH 354 ( 1 ) 57 - 64 2017.5

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

The double-stranded RNA-dependent kinase (PKR), which is activated by double stranded RNA, induces inflammation by regulating NF-kappa B signaling. The NLR family pyrin domain-containing 3 (NLRP3) inflammasome also modulates inflammation in response to infection. Porphyromonas gingivalis (P.gingivalis) is an oral bacterium which is implicated in the pathogenesis of periodontal diseases. We previously reported that PKR is a key modulator of bone metabolism and inflammation in the periodontal tissue. PKR was also reported to induce inflammation in response to microbes by regulating the NLRP3 inflammasome, suggesting that PKR could affect inflammation along with NLRP3 in periodontal diseases. In this study, we investigated the effects of PKR on NLRP3 expression and NF-kappa B activity in P. gingivalis infected osteoblasts. We first constructed a SNAP26b-tagged P.gingivalis (SNAP-P. g.) and traced its internalization into the cell. SNAP-P. g. increased the activity of PKR and NF-kappa B and also induced NLRP3 expression in osteoblasts. Inhibition of NF-kappa B attenuated SNAP -P. g. induced NLRP3 expression. The knockdown of PKR using shRNA decreased both the activity of NF-kappa B and the expression of NLRP3 induced by SNAP-P.g.. We therefore concluded that in osteoblasts, P. gingivalis activated PKR, which in turn increased NLRP3 expression by activating NF-kappa B. Our results suggest that PKR modulates inflammation by regulating the expression of the NLRP3 inflammasome through the NF-kappa B pathway in periodontal diseases.

DOI： 10.1016/j.yexcr.2017.03.028

PKR regulates LPS-induced osteoclast formation and bone destruction in vitro and in vivo Reviewed

J. Teramachi, Y. Inagaki, H. Shinohara, H. Okamura, D. Yang, K. Ochiai, R. Baba, H. Morimoto, T. Nagata, T. Haneji

ORAL DISEASES 23 ( 2 ) 181 - 188 2017.3

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

ObjectiveIn this study, we aimed to clarify the precise mechanism underlying lipopolysaccharide (LPS)-induced osteoclastogenesis in periodontal disease with a special reference to double-stranded RNA-dependent protein kinase (PKR).
Material and MethodsWe dissected the role of PKR in LPS-induced osteoclast differentiation and function using primary mouse bone marrow cells and RAW264.7 pre-osteoclastic cell line. We used a rat experimental periodontitis (PD) model induced by ligature placement with a Porphyromonas gingivalis LPS injection (PD rat) and analyzed the therapeutic effects of C16, a PKR inhibitor, on bone loss in PD rats.
ResultsProtein kinase is strongly upregulated and phosphorylated by LPS in the osteoclasts. The inhibition of PKR suppressed LPS-stimulated osteoclast formation and activation. PKR inhibition also suppressed the LPS-mediated activation of NF-B and MAPK, which are critical pathways for osteoclastogenesis. High expressions of PKR were detected in osteoclasts of PD rats, and the treatment with C16 effectively prevented alveolar bone destruction in PD rats.
ConclusionsPKR plays a pivotal role in LPS-induced bone loss in PD and, thus, has potential as a therapeutic target for PD.

DOI： 10.1111/odi.12592

Role of Protein Phosphatase 2A in Osteoblast Differentiation and Function Reviewed

Hirohiko Okamura, Kaya Yoshida, Hiroyuki Morimoto, Jumpei Teramachi, Kazuhiko Ochiai, Tatsuji Haneji, Akihito Yamamoto

JOURNAL OF CLINICAL MEDICINE 6 ( 3 ) 2017.3

Language：English Publisher：MDPI AG

The reversible phosphorylation of proteins plays hugely important roles in a variety of cellular processes, such as differentiation, proliferation, and apoptosis. These processes are strictly controlled by protein kinases (phosphorylation) and phosphatases (de-phosphorylation). Here we provide a brief history of the study of protein phosphorylation, including a summary of different types of protein kinases and phosphatases. One of the most physiologically important serine/ threonine phosphatases is PP2A. This review provides a description of the phenotypes of various PP2A transgenic mice and further focuses on the known functions of PP2A in bone formation, including its role in osteoblast differentiation and function. A reduction in PP2A promotes bone formation and osteoblast differentiation through the regulation of bone-related transcription factors such as Osterix. Interestingly, downregulation of PP2A also stimulates adipocyte differentiation from undifferentiated mesenchymal cells under the appropriate adipogenic differentiation conditions. In osteoblasts, PP2A is also involved in the ability to control osteoclastogenesis as well as in the proliferation and metastasis of osteosarcoma cells. Thus, PP2A is considered to be a comprehensive factor in controlling the differentiation and function of cells derived from mesenchymal cells such as osteoblasts and adipocytes.

DOI： 10.3390/jcm6030023

Involvement of interleukin-23 induced by Porphyromonas endodontalis lipopolysaccharide in osteoclastogenesis Reviewed

Nan Ma, Di Yang, Hirohiko Okamura, Jumpei Teramachi, Tomokazu Hasegawa, Lihong Qiu, Tatsuji Haneji

MOLECULAR MEDICINE REPORTS 15 ( 2 ) 559 - 566 2017.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SPANDIDOS PUBL LTD

Periapical lesions are characterized by the destruction of periapical bone, and occur as a result of local inflammatory responses to root canal infection by microorganisms including Porphyromonas endodontalis (P. endodontalis). P. endodontalis and its primary virulence factor, lipopolysaccharide (LPS), are associated with the development of periapical lesions and alveolar bone loss. Interleukin-23 (IL-23) is critical in the initiation and progression of periodontal disease via effects on peripheral bone metabolism. The present study investigated the expression of IL-23 in tissue where a periapical lesion was present, and the effect of P. endodontalis LPS on the expression of IL-23 in periodontal ligament (PDL) cells. Reverse transcription- quantitative polymerase chain reaction and immunohistochemistry revealed increased levels of IL-23 expression in tissue with periapical lesions compared with healthy PDL tissue. Treatment with P. endodontalis LPS increased the expression of IL-23 in the SH-9 human PDL cell line. BAY11-7082, a nuclear factor kappa B inhibitor, suppressed P. endodontalis LPS-induced IL-23 expression in SH-9 cells. Treatment of RAW264.7 cells with conditioned medium from P. endodontalis LPS-treated SH-9 cells promoted osteoclastogenesis. By contrast, RAW264.7 cells treated with conditioned medium from IL-23-knockdown SH-9 cells underwent reduced levels of osteoclastogenesis. The results of the present study indicated that the expression of IL-23 in PDL cells induced by P. endodontalis LPS treatment may be involved in the progression of periapical lesions via stimulation of the osteoclastogenesis process.

DOI： 10.3892/mmr.2016.6041

Protein phosphatase 2A C alpha regulates proliferation, migration, and metastasis of osteosarcoma cells Reviewed

Di Yang, Hirohiko Okamura, Hiroyuki Morimoto, Jumpei Teramachi, Tatsuji Haneji

LABORATORY INVESTIGATION 96 ( 10 ) 1050 - 1062 2016.10

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

Osteosarcoma is the most frequent primary bone tumor. Serine/threonine protein phosphatase 2A (PP2A) participates in regulating many important physiological processes, such as cell cycle, growth, apoptosis, and signal transduction. In this study, we examined the expression and function of PP2A C alpha in osteosarcoma cells. PP2A C alpha expression was expected to be higher in malignant osteosarcoma tissues. PP2A C alpha expression level and PP2A activity was higher in malignant osteosarcoma LM8 cells compared with that in primary osteoblasts and in the osteoblast-like cell line MC3T3-E1. Okadaic acid, an inhibitor of PP2A, reduced cell viability and induced apoptosis in LM8 cells. PP2A C alpha-knockdown LM8 cells (shPP2A) exhibited less striking filopodial and lamellipodial structures than that in original LM8 cells. Focal adhesion kinase phosphorylation and NF-kappa B activity decreased in shPP2A-treated cells. Sensitivity to serum deprivation-induced apoptosis increased in shPP2A-treated cells, accompanied by a lower expression level of anti-apoptotic BCL-2 in these cells. Reduction of PP2A C alpha resulted in a decrease in the migration ability of LM8 cells in vitro. Reduction in PP2A C alpha levels in vivo suppressed proliferation and metastasis in LM8 cells. PP2A C alpha expression was also higher in human osteosarcoma MG63 and SaOS-2 cells than that in primary osteoblasts and MC3T3-E1 cells, and reduction in PP2A C alpha levels suppressed the cell proliferation rate and migration ability of MG63 cells. These results indicate that PP2A C alpha has a critical role in the proliferation and metastasis of osteosarcoma cells; therefore, its inhibition could potentially suppress the malignancy of osteosarcoma cells.

DOI： 10.1038/labinvest.2016.82

Porphyromonas gingivalis attenuates the insulin-induced phosphorylation and translocation of forkhead box protein O1 in human hepatocytes Reviewed

Haruna Takamura, Kaya Yoshida, Hirohiko Okamura, Natsumi Fujiwara, Kazumi Ozaki

ARCHIVES OF ORAL BIOLOGY 69 19 - 24 2016.9

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

Objective: Porphyromonas gingivalis (P. gingivalis) is a pathogen involved in periodontal disease. Recently, periodontal disease has been demonstrated to increase the risk of developing diabetes mellitus, although the molecular mechanism is not fully understood. Forkhead box protein O1 (FoxO1) is a transcriptional factor that regulates gluconeogenesis in the liver. Gluconeogenesis is a key process in the induction of diabetes mellitus; however, little is known regarding the relationship between periodontal disease and gluconeogenesis. In this study, to investigate whether periodontal disease influences hepatic gluconeogenesis, we examined the effects of P. gingivalis on the phosphorylation and translocation of FoxO1 in insulin-induced human hepatocytes.
Design: The human hepatocyte HepG2 was treated with insulin and Akt and FoxO1 phosphorylation was detected by western blot analysis. The localization of phosphorylated FoxO1 was detected by immunocytochemistry and western blot analysis. HepG2 cells were treated with SNAP26b-tagged P. gingivalis (SNAP-P.g.) before insulin stimulation, and then the changes in Akt and FoxO1 were determined by western blot analysis and immunocytochemistry.
Results: Insulin (100 nM) induced FoxO1 phosphorylation 60 min after treatment in HepG2 cells. Phosphorylated FoxO1 translocated to the cytoplasm. SNAP-P.g. internalized into HepG2 cells and decreased Akt and FoxO1 phosphorylation induced by insulin. The effect of insulin on FoxO1 translocation was also attenuated by SNAP-P.g.
Conclusions: Our study shows that P. gingivalis decreases the phosphorylation and translocation of FoxO induced by insulin in HepG2 cells. Our results suggest that periodontal disease may increase hepatic gluconeogenesis by reducing the effects of insulin on FoxO1. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.archoralbio.2016.05.010

Histone demethylase Jmjd3 regulates osteoblast apoptosis through targeting anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bim. Reviewed International journal

Di Yang, Hirohiko Okamura, Jumpei Teramachi, Tatsuji Haneji

Biochimica et biophysica acta 1863 ( 4 ) 650 - 9 2016.4

Language：English

Posttranslational modifications including histone methylation regulate gene transcription through directly affecting the structure of chromatin. Trimethylation of histone H3K27 (H3K27me3) contributes to gene silencing and the histone demethylase Jumonji domain-containing 3 (Jmjd3) specifically removes the methylation of H3K27me3, followed by the activation of gene expression. In the present study, we explored the roles of Jmjd3 in regulating osteoblast apoptosis. Knockdown of Jmjd3 promoted osteoblast apoptosis induced by serum deprivation with decreased mitochondrial membrane potential and increased levels of caspase-3 activation, PARP cleavage, and DNA fragmentation. B cell lymphoma-2 (Bcl-2), an anti-apoptotic protein, was down-regulated by knockdown of Jmjd3 through retaining H3K27me3 on its promoter region. Knockdown of Jmjd3 increased the pro-apoptotic activity of Bim through inhibiting ERK-dependent phosphorylation of Bim. Protein kinase D1 (PKD1), which stimulates ERK phosphorylation, decreased in the Jmjd3-knockdown cells and introduction of PKD1 relieved osteoblast apoptosis in the Jmjd3-knockdown cells through increasing ERK-regulated Bim phosphorylation. These results suggest that Jmjd3 regulates osteoblast apoptosis through targeting Bcl-2 expression and Bim phosphorylation.

DOI： 10.1016/j.bbamcr.2016.01.006

Histone demethylase Jmjd3 regulates osteoblast apoptosis through targeting anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bim Reviewed

Di Yang, Hirohiko Okamura, Jumpei Teramachi, Tatsuji Haneji

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 1863 ( 4 ) 650 - 659 2016.4

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

Posttranslational modifications including histone methylation regulate gene transcription through directly affecting the structure of chromatin. Trimethylation of histone H3K27 (H3K27me3) contributes to gene silencing and the histone demethylase Jumonji domain-containing 3 (Jmjd3) specifically removes the methylation of H3K27me3, followed by the activation of gene expression. In the present study, we explored the roles of Jmjd3 in regulating osteoblast apoptosis. Knockdown of Jmjd3 promoted osteoblast apoptosis induced by serum deprivation with decreased mitochondrial membrane potential and increased levels of caspase-3 activation, PARP cleavage, and DNA fragmentation. B cell lymphoma-2 (Bcl-2), an anti-apoptotic protein, was down regulated by knockdown of Jmjd3 through retaining H3K27me3 on its promoter region. Knockdown of Jmjd3 increased the pro-apoptotic activity of Bim through inhibiting ERK-dependent phosphorylation of Bim. Protein kinase D1 (PKD1), which stimulates ERK phosphorylation, decreased in the Jmjd3-knockdown cells and introduction of PKD1 relieved osteoblast apoptosis in the Jmjd3-knockdown cells through increasing ERK-regulated Bim phosphorylation. These results suggest that Jmjd3 regulates osteoblast apoptosis through targeting Bcl-2 expression and Bim phosphorylation. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bbamcr.2016.01.006

PKR regulates LPS-induced osteoclast formation and bone destruction in vitro and in vivo. Reviewed

Jumpei Teramachi, Yuji Inagaki, Hiroki Shinohara, Hirohiko Okamura, Di Yang, Kazuhiko Ochiai, Ryoko Baba, Hiroyuki Morimoto, Toshihiko Nagata, Tatsuji Haneji

Oral Diseases 2016

Histone Demethylase Utx Regulates Differentiation and Mineralization in Osteoblasts Reviewed

Di Yang, Hirohiko Okamura, Jumpei Teramachi, Tatsuji Haneji

JOURNAL OF CELLULAR BIOCHEMISTRY 116 ( 11 ) 2628 - 2636 2015.11

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

Alteration of methylation status of lysine 27 on histone H3 (H3K27) associates with dramatic changes in gene expression in response to various differentiation signals. Demethylation of H3K27 is controlled by specific histone demethylases including ubiquitously transcribed tetratricopeptide repeat X chromosome (Utx). However, the role of Utx in osteoblast differentiation remains unknown. In this study, we examined whether Utx should be involved in osteoblast differentiation. Expression of Utx increased during osteoblast differentiation in MC3T3-E1 cells and primary osteoblasts. GSK-J1, a potent inhibitor of H3K27 demethylase, increased the levels of trimethylated H3K27 (H3K27me3) and decreased the expressions of Runx2 and Osterix and ALP activity in MC3T3-E1 cells. Stable knockdown of Utx by shRNA attenuated osteoblast differentiation and decreased ALP activity, calcium content, and bone-related gene expressions. Silencing of Utx increased the level of H3K27me3 on the promoter regions of Runx2 and Osterix and decreased the promoter activities of Runx2 and Osterix. Taken together, our present results propose that Utx plays important roles in osteoblast differentiation by controlling the expressions of Runx2 and Osterix. J. Cell. Biochem. 116: 2628-2636, 2015. (c) 2015 Wiley Periodicals, Inc.

DOI： 10.1002/jcb.25210

Double Stranded RNA-Dependent Protein Kinase is Necessary for TNF--Induced Osteoclast Formation In Vitro and In Vivo Reviewed

Hiroki Shinohara, Jumpei Teramachi, Hirohiko Okamura, Di Yang, Toshihiko Nagata, Tatsuji Haneji

JOURNAL OF CELLULAR BIOCHEMISTRY 116 ( 9 ) 1957 - 1967 2015.9

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

Double-stranded RNA-dependent protein kinase (PKR) is involved in cell cycle progression, cell proliferation, cell differentiation, tumorgenesis, and apoptosis. We previously reported that PKR is required for differentiation and calcification in osteoblasts. TNF- plays a key role in osteoclast differentiation. However, it is unknown about the roles of PKR in the TNF--induced osteoclast differentiation. The expression of PKR in osteoclast precursor RAW264.7 cells increased during TNF--induced osteoclastogenesis. The TNF--induced osteoclast differentiation in bone marrow-derived macrophages and RAW264.7 cells was markedly suppressed by the pretreatment of PKR inhibitor, 2-aminopurine (2AP), as well as gene silencing of PKR. The expression of gene markers in the differentiated osteoclasts including TRAP, Calcitonin receptor, cathepsin K, and ATP6V0d2 was also suppressed by the 2AP treatment. Bone resorption activity of TNF--induced osteoclasts was also supressed by 2AP treatment. Inhibition of PKR supressed the TNF--induced activation of NF-B and MAPK in RAW264.7 cells. 2AP inhibited both the nuclear translocation of NF-B and its transcriptional activity in RAW264.7 cells. 2AP inhibited the TNF--induced expression of NFATc1 and c-fos, master transcription factors in osteoclastogenesis. TNF--induced nuclear translocation of NFATc1 in mature osteoclasts was clearly inhibited by the 2AP treatment. The PKR inhibitor C16 decreased the TNF--induced osteoclast formation and bone resorption in mouse calvaria. The present study indicates that PKR is necessary for the TNF--induced osteoclast differentiation in vitro and in vivo. J. Cell. Biochem. 116: 1957-1967, 2015. (c) 2015 Wiley Periodicals, Inc.

DOI： 10.1002/jcb.25151

Preventive Effect of Daiokanzoto (TJ-84) on 5-Fluorouracil-Induced Human Gingival Cell Death through the Inhibition of Reactive Oxygen Species Production Reviewed

Kaya Yoshida, Masami Yoshioka, Hirohiko Okamura, Satomi Moriyama, Kazuyoshi Kawazoe, Daniel Grenier, Daisuke Hinode

PLOS ONE 9 ( 11 ) e112689 2014.11

Language：English Publishing type：Research paper (scientific journal) Publisher：PUBLIC LIBRARY SCIENCE

Daiokanzoto (TJ-84) is a traditional Japanese herbal medicine (Kampo formulation). While many Kampo formulations have been reported to regulate inflammation and immune responses in oral mucosa, there is no evidence to show that TJ-84 has beneficial effects on oral mucositis, a disease resulting from increased cell death induced by chemotherapeutic agents such as 5-fluorouracil (5-FU). In order to develop effective new therapeutic strategies for treating oral mucositis, we investigated (i) the mechanisms by which 5-FU induces the death of human gingival cells and (ii) the effects of TJ-84 on biological events induced by 5-FU. 5-FU-induced lactate dehydrogenase (LDH) release and pore formation in gingival cells (Sa3 cell line) resulted in cell death. Incubating the cells with 5-FU increased the expression of nucleotide-binding domain and leucine-rich repeat containing PYD-3 (NLRP3) and caspase-1. The cleavage of caspase-1 was observed in 5-FU-treated cells, which was followed by an increased secretion of interleukin (IL)-1 beta. The inhibition of the NLRP3 pathway slightly decreased the effects of 5-FU on cell viability and LDH release, suggesting that NLRP3 may be in part involved in 5-FU-induced cell death. TJ-84 decreased 5-FU-induced LDH release and cell death and also significantly inhibited the depolarization of mitochondria and the up-regulation of 5-FU-induced reactive oxygen species (ROS) and nitric oxide (NO) production. The transcriptional factor, nuclear factor-kappa B (NF-kappa B) was not involved in the 5-FU-induced cell death in Sa3 cells. In conclusion, we provide evidence suggesting that the increase of ROS production in mitochondria, rather than NLRP3 activation, was considered to be associated with the cell death induced by 5-FU. The results also suggested that TJ-84 may attenuate 5-FU-induced cell death through the inhibition of mitochondrial ROS production.

DOI： 10.1371/journal.pone.0112689

　 PREV - NEXT 　

1
2
3
4
5
6