Faculty Profiles - TSUJI Kenji

Papers - TSUJI Kenji

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Deep Learning Could Diagnose Diabetic Nephropathy with Renal Pathological Immunofluorescent Images. Reviewed International journal

Shinji Kitamura, Kensaku Takahashi, Yizhen Sang, Kazuhiko Fukushima, Kenji Tsuji, Jun Wada

Diagnostics (Basel, Switzerland) 10 ( 7 ) 2020.7

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

Artificial Intelligence (AI) imaging diagnosis is developing, making enormous steps forward in medical fields. Regarding diabetic nephropathy (DN), medical doctors diagnose them with clinical course, clinical laboratory data and renal pathology, mainly evaluate with light microscopy images rather than immunofluorescent images because there are no characteristic findings in immunofluorescent images for DN diagnosis. Here, we examined the possibility of whether AI could diagnose DN from immunofluorescent images. We collected renal immunofluorescent images from 885 renal biopsy patients in our hospital, and we created a dataset that contains six types of immunofluorescent images of IgG, IgA, IgM, C3, C1q and Fibrinogen for each patient. Using the dataset, 39 programs worked without errors (Area under the curve (AUC): 0.93). Five programs diagnosed DN completely with immunofluorescent images (AUC: 1.00). By analyzing with Local interpretable model-agnostic explanations (Lime), the AI focused on the peripheral lesion of DN glomeruli. On the other hand, the nephrologist diagnostic ratio (AUC: 0.75833) was slightly inferior to AI diagnosis. These findings suggest that DN could be diagnosed only by immunofluorescent images by deep learning. AI could diagnose DN and identify classified unknown parts with the immunofluorescent images that nephrologists usually do not use for DN diagnosis.

DOI： 10.3390/diagnostics10070466

Adult kidney stem/progenitor cells contribute to regeneration through the secretion of trophic factors. Reviewed International journal

Kenji Tsuji, Shinji Kitamura, Yizhen Sang, Kazuhiko Fukushima, Jun Wada

Stem cell research 46 101865 - 101865 2020.7

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

Adult kidney stem cells are known to have important roles in renal regeneration after acute kidney injury. Although trophic factors from tissue stem cells have been reported to promote the regeneration of other organs, there is limited number of evidence of this phenomenon in the kidneys. Here, we explored the effects of secreted factors from kidney stem cells. We intraperitoneally administered culture supernatant obtained from adult rat kidney stem/progenitor cells into rat kidney ischemia/reperfusion injury models, and the treatment significantly ameliorated renal tubulointerstitial injury, suppressed tubular cell apoptosis, diminished inflammation and promoted the proliferation of both residual renal cells and immature cells. In vitro, treatment with culture supernatant from kidney stem cells significantly promoted cell proliferation and suppressed cisplatin-induced cell apoptosis in both normal rat kidney cells and kidney stem cells. In addition, treatment with culture supernatant increased the expression of nestin in normal rat kidney cells, suggesting the dedifferentiation of tubular cells into stem-like cells. Analysis of the culture supernatant revealed that it contained a variety of growth factors. Taken together, the results suggest that these factors together lead to renal regeneration. In conclusion, adult kidney stem cells contribute to renal regeneration indirectly through the secretion of regenerative factors.

DOI： 10.1016/j.scr.2020.101865

Semaphorin3A-Inhibitor Ameliorates Doxorubicin-Induced Podocyte Injury. Reviewed International journal

Yizhen Sang, Kenji Tsuji, Akiko Inoue-Torii, Kazuhiko Fukushima, Shinji Kitamura, Jun Wada

International journal of molecular sciences 21 ( 11 ) 2020.6

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

Podocyte injury is an independent risk factor for the progression of renal diseases. Semaphorin3A (SEMA3A), expressed in podocytes and tubular cells in the mammalian adult kidneys, has been reported to regulate diverse biological functions and be associated with renal diseases. Here, we investigated pathological roles of SEMA3A signaling on podocyte injury using a doxorubicin (Dox)-induced mouse model and examined the therapeutic effect of SEMA3A-inhibitor (SEMA3A-I). We demonstrated that Dox caused massive albuminuria and podocyte apoptosis as well as an increase of SEMA3A expression in podocytes, all of which were ameliorated with SEMA3A-I treatment. In addition, c-Jun N-terminal kinase (JNK), known as a downstream of SEMA3A signaling, was activated in Dox-injected mouse podocytes while SEMA3A-I treatment partially blocked the activation. In vitro, SEMA3A-I protected against Dox-induced podocyte apoptosis and recombinant SEMA3A caused podocyte apoptosis with activation of JNK signaling. JNK inhibitor, SP600125, attenuated SEMA3A-induced podocyte apoptosis, indicating that the JNK pathway would be involved in SEMA3A-induced podocyte apoptosis. Furthermore, the analysis of human data revealed a positive correlation between levels of urinary SEMA3A and protein, suggesting that SEMA3A is associated with podocyte injury. In conclusion, SEMA3A has essential roles in podocyte injury and it would be the therapeutic target for protecting from podocyte injury.

DOI： 10.3390/ijms21114099

Sodium Glucose Co-Transporter 2 Inhibitor Ameliorates Autophagic Flux Impairment on Renal Proximal Tubular Cells in Obesity Mice. Reviewed International journal

Kazuhiko Fukushima, Shinji Kitamura, Kenji Tsuji, Yizhen Sang, Jun Wada

International journal of molecular sciences 21 ( 11 ) 2020.6

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

Obesity is supposed to cause renal injury via autophagy deficiency. Recently, sodium glucose co-transporter 2 inhibitors (SGLT2i) were reported to protect renal injury. However, the mechanisms of SGLT2i for renal protection are unclear. Here, we investigated the effect of SGLT2i for autophagy in renal proximal tubular cells (PTCs) on obesity mice. We fed C57BL/6J mice with a normal diet (ND) or high-fat and -sugar diet (HFSD) for nine weeks, then administered SGLT2i, empagliflozin, or control compound for one week. Each group contained N = 5. The urinary N-acetyl-beta-d-glucosaminidase level in the HFSD group significantly increased compared to ND group. The tubular damage was suppressed in the SGLT2i-HFSD group. In electron microscopic analysis, multi lamellar bodies that increased in autophagy deficiency were increased in PTCs in the HFSD group but significantly suppressed in the SGLT2i group. The autophagosomes of damaged mitochondria in PTCs in the HFSD group frequently appeared in the SGLT2i group. p62 accumulations in PTCs were significantly increased in HFSD group but significantly suppressed by SGLT2i. In addition, the mammalian target of rapamycin was activated in the HFSD group but significantly suppressed in SGLT2i group. These data suggest that SGLT2i has renal protective effects against obesity via improving autophagy flux impairment in PTCs on a HFSD.

DOI： 10.3390/ijms21114054

Pembrolizumab-induced hypothyroidism caused reversible increased serum creatinine levels: a case report. Reviewed International journal

Natsumi Matsuoka, Kenji Tsuji, Eiki Ichihara, Takayuki Hara, Kazuhiko Fukushima, Kishio Toma, Shinji Kitamura, Kenichi Inagaki, Hitoshi Sugiyama, Jun Wada

BMC nephrology 21 ( 1 ) 113 - 113 2020.3

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

BACKGROUND: The advent of immune checkpoint inhibitors (ICIs) has significantly improved the prognosis of patients with advanced malignancies. On the other hand, these drugs might cause immune-related adverse events (irAEs) including endocrinopathies and nephropathies. Thyroid dysfunction is one of the most common irAEs. For ICIs-induced nephropathies, most cases are due to tubulointerstitial nephritis, which might require steroid treatment. Here, we report a patient with non-small cell lung cancer treated with ICI who developed increased serum creatinine (s-Cr) levels due to ICIs-induced hypothyroidism. CASE PRESENTATION: A 57-year-old Asian man with refractory non-small cell lung cancer under ICIs therapy (pembrolizumab, an anti-programmed cell death-1 monoclonal antibody) developed increased s-Cr levels 5 months after the pembrolizumab initiation. His laboratory data, renal biopsy, and Gallium-67 scintigraphy findings denied pembrolizumab-induced tubulointerstitial nephritis. His renal function was correlated with thyroid function. Despite the increase of s-Cr levels, serum cystatin C levels were normal, which could be explained by the hypothyroidism. Levothyroxine treatment improved renal function as well as thyroid function. Then pembrolizumab was resumed, and both his thyroid and renal function remained normal level. Ultimately, we concluded that the increased s-Cr levels were caused by pembrolizumab-induced hypothyroidism. CONCLUSION: All clinicians involved in ICI treatment need to recognize the possible increase in s-Cr levels caused by ICIs-induced hypothyroidism, and we propose monitoring serum cystatin C levels to differentiate ICIs-induced hypothyroidism from tubulointerstitial nephritis before invasive renal biopsies or steroid treatment, which are recommended by the prescribing information for pembrolizumab, are performed.

DOI： 10.1186/s12882-020-01775-z

Immunomodulatory and Regenerative Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Renal Diseases. Reviewed International journal

Kenji Tsuji, Shinji Kitamura, Jun Wada

International journal of molecular sciences 21 ( 3 ) 2020.1

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

Mesenchymal stem cells (MSCs) have immunomodulatory and regenerative effects in many organs, including the kidney. Emerging evidence has shown that the trophic effects from MSCs are mainly mediated by the paracrine mechanism rather than the direct differentiation of MSCs into injured tissues. These secretomes from MSCs include cytokines, growth factors, chemokines and extracellular vesicles (EVs) containing microRNAs, mRNAs, and proteins. Many research studies have revealed that secretomes from MSCs have potential to ameliorate renal injury in renal disease models, including acute kidney injury and chronic kidney disease through a variety of mechanisms. These trophic mechanisms include immunomodulatory and regenerative effects. In addition, accumulating evidence has uncovered the specific factors and therapeutic mechanisms in MSC-derived EVs. In this article, we summarize the recent advances of immunomodulatory and regenerative effects of EVs from MSCs, especially focusing on the microRNAs.

DOI： 10.3390/ijms21030756

Integrin-Linked Kinase Deficiency in Collecting Duct Principal Cell Promotes Necroptosis of Principal Cell and Contributes to Kidney Inflammation and Fibrosis. Reviewed International journal

Ming Huang, Shuai Zhu, Huihui Huang, Jinzhao He, Kenji Tsuji, William W Jin, Dongping Xie, Onju Ham, Diane E Capen, Weining Lu, Teodor G Păunescu, Baoxue Yang, Hua A Jenny Lu

Journal of the American Society of Nephrology : JASN 30 ( 11 ) 2073 - 2090 2019.11

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

BACKGROUND: Necroptosis is a newly discovered cell death pathway that plays a critical role in AKI. The involvement of integrin-linked kinase (ILK) in necroptosis has not been studied. METHODS: We performed experiments in mice with an Ilk deletion in collecting duct (CD) principal cells (PCs), and cultured tubular epithelial cells treated with an ILK inhibitor or ILK siRNA knockdown. RESULTS: Ilk deletion in CD PCs resulted in acute tubular injury and early mortality in mice. Progressive interstitial fibrosis and inflammation associated with the activation of the canonical TGF-β signaling cascade were detected in the kidneys of the mice lacking ILK in the CD PCs. In contrast to the minimal apoptosis detected in the animals' injured CDs, widespread necroptosis was present in ILK-deficient PCs, characterized by cell swelling, deformed mitochondria, and rupture of plasma membrane. In addition, ILK deficiency resulted in increased expression and activation of necroptotic proteins MLKL and RIPK3, and membrane translocation of MLKL in CD PCs. ILK inhibition and siRNA knockdown reduced cell survival in cultured tubular cells, concomitant with increased membrane accumulation of MLKL and/or phospho-MLKL. Administration of a necroptosis inhibitor, necrostatin-1, blocked cell death in vitro and significantly attenuated inflammation, interstitial fibrosis, and renal failure in ILK-deficient mice. CONCLUSIONS: The study demonstrates the critical involvement of ILK in necroptosis through modulation of the RIPK3 and MLKL pathway and highlights the contribution of CD PC injury to the development of inflammation and interstitial fibrosis of the kidney.

DOI： 10.1681/ASN.2018111162

Pathological cardiac remodeling occurs early in CKD mice from unilateral urinary obstruction, and is attenuated by Enalapril. Reviewed International journal

Onju Ham, William Jin, Lei Lei, Hui Hui Huang, Kenji Tsuji, Ming Huang, Jason Roh, Anthony Rosenzweig, Hua A Jenny Lu

Scientific reports 8 ( 1 ) 16087 - 16087 2018.10

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

Cardiovascular disease constitutes the leading cause of mortality in patients with chronic kidney disease (CKD) and end-stage renal disease. Despite increasing recognition of a close interplay between kidney dysfunction and cardiovascular disease, termed cardiorenal syndrome (CRS), the underlying mechanisms of CRS remain poorly understood. Here we report the development of pathological cardiac hypertrophy and fibrosis in early stage non-uremic CKD. Moderate kidney failure was induced three weeks after unilateral urinary obstruction (UUO) in mice. We observed pathological cardiac hypertrophy and increased fibrosis in UUO-induced CKD (UUO/CKD) animals. Further analysis indicated that this cardiac fibrosis was associated with increased expression of transforming growth factor β (TGF-β) along with significant upregulation of Smad 2/3 signaling in the heart. Moreover early treatment of UUO/CKD animals with an angiotensin-converting-enzyme inhibitor (ACE I), Enalapril, significantly attenuated cardiac fibrosis. Enalapril antagonized activation of the TGF-β signaling pathway in the UUO/CKD heart. In summary our study demonstrates the presence of pathological cardiac hypertrophy and fibrosis in mice early in UUO-induced CKD, in association with early activation of the TGF-β/Smad signaling pathway. We also demonstrate the beneficial effect of ACE I in alleviating this early fibrogenic process in the heart in UUO/CKD animals.

DOI： 10.1038/s41598-018-34216-x

Manganese promotes intracellular accumulation of AQP2 via modulating F-actin polymerization and reduces urinary concentration in mice. Reviewed International journal

Lei Lei, Ming Huang, Limin Su, Dongping Xie, Fahmy A Mamuya, Onju Ham, Kenji Tsuji, Teodor G Păunescu, Baoxue Yang, Hua A Jenny Lu

American journal of physiology. Renal physiology 314 ( 2 ) F306-F316 - F316 2018.2

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

Aquaporin-2 (AQP2) is a water channel protein expressed in principal cells (PCs) of the kidney collecting ducts (CDs) and plays a critical role in mediating water reabsorption and urine concentration. AQP2 undergoes both regulated trafficking mediated by vasopressin (VP) and constitutive recycling, which is independent of VP. For both pathways, actin cytoskeletal dynamics is a key determinant of AQP2 trafficking. We report here that manganese chloride (MnCl2) is a novel and potent regulator of AQP2 trafficking in cultured cells and in the kidney. MnCl2 treatment promoted internalization and intracellular accumulation of AQP2. The effect of MnCl2 on the intracellular accumulation of AQP2 was associated with activation of RhoA and actin polymerization without modification of AQP2 phosphorylation. Although the level of total and phosphorylated AQP2 did not change, MnCl2 treatment impeded VP-induced phosphorylation of AQP2 at its serine-256, -264, and -269 residues and dephosphorylation at serine 261. In addition, MnCl2 significantly promoted F-actin polymerization along with downregulation of RhoA activity and prevented VP-induced membrane accumulation of AQP2. Finally, MnCl2 treatment in mice resulted in significant polyuria and reduced urinary concentration, likely due to intracellular relocation of AQP2 in the PCs of kidney CDs. More importantly, the reduced urinary concentration caused by MnCl2 treatment in animals was not corrected by VP. In summary, our study identified a novel effect of MnCl2 on AQP2 trafficking through modifying RhoA activity and actin polymerization and uncovered its potent impact on water diuresis in vivo.

DOI： 10.1152/ajprenal.00391.2017

Secretomes from Mesenchymal Stem Cells against Acute Kidney Injury: Possible Heterogeneity. Reviewed International journal

Kenji Tsuji, Shinji Kitamura, Jun Wada

Stem cells international 2018 8693137 - 8693137 2018

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

A kidney has the ability to regenerate itself after a variety of renal injuries. Mesenchymal stem cells (MSCs) have been shown to ameliorate tissue damages during renal injuries and diseases. The regenerations induced by MSCs are primarily mediated by the paracrine release of soluble factors and extracellular vesicles, including exosomes and microvesicles. Extracellular vesicles contain proteins, microRNAs, and mRNAs that are transferred into recipient cells to induce several repair signaling pathways. Over the past few decades, many studies identified trophic factors from MSCs, which attenuate renal injury in a variety of animal acute kidney injury models, including renal ischemia-reperfusion injury and drug-induced renal injury, using microarray and proteomic analysis. Nevertheless, these studies have revealed the heterogeneity of trophic factors from MSCs that depend on the cell origins and different stimuli including hypoxia, inflammatory stimuli, and aging. In this review article, we summarize the secretomes and regenerative mechanisms induced by MSCs and highlight the possible heterogeneity of trophic factors from different types of MSC and different circumstances for renal regeneration.

DOI： 10.1155/2018/8693137

Deletion of β1-integrin in collecting duct principal cells leads to tubular injury and renal medullary fibrosis. Reviewed International journal

Fahmy A Mamuya, Dongping Xie, Lei Lei, Ming Huang, Kenji Tsuji, Diane E Capen, BaoXue Yang, Ralph Weissleder, Teodor G Păunescu, Hua A Jenny Lu

American journal of physiology. Renal physiology 313 ( 4 ) F1026-F1037 - F1037 2017.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSIOLOGICAL SOC

The renal collecting duct (CD) contains two major cell types, intercalated (ICs) and principal cells (PCs). A previous report showed that deletion of β1-integrin in the entire renal CD causes defective CD morphogenesis resulting in kidney dysfunction. However, subsequent deletion of β1-integrin specifically in ICs and PCs, respectively, did not cause any morphological defects in the CDs. The discrepancy between these studies prompts us to reinvestigate the role of β1-integrin in CD cells, specifically in the PCs. We conditionally deleted β1-integrin in mouse CD PCs using a specific aquaporin-2 (AQP2) promoter Cre-LoxP system. The resulting mutant mice, β-1f/fAQP2-Cre+, had lower body weight, failed to thrive, and died around 8-12 wk. Their CD tubules were dilated, and some of them contained cellular debris. Increased apoptosis and proliferation of PCs were observed in the dilated CDs. Trichrome staining and electron microscopy revealed the presence of peritubular and interstitial fibrosis that is associated with increased production of extracellular matrix proteins including collagen type IV and fibronectin, as detected by immunoblotting. Further analysis revealed a significantly increased expression of transforming growth factor-β (TGF-β)-induced protein, fibronectin, and TGF-β receptor-1 mRNAs and concomitantly increased phosphorylation of SMAD-2 that indicates the activation of the TGF-β signaling pathway. Therefore, our data reveal that normal expression of β1-integrin in PCs is a critical determinant of CD structural and functional integrity and further support the previously reported critical role of β1-integrin in the development and/or maintenance of the CD structure and function.

DOI： 10.1152/ajprenal.00038.2017

Ultrastructural Characterization of the Glomerulopathy in Alport Mice by Helium Ion Scanning Microscopy (HIM). Reviewed International journal

Kenji Tsuji, Hani Suleiman, Jeffrey H Miner, James M Daley, Diane E Capen, Teodor G Păunescu, Hua A Jenny Lu

Scientific reports 7 ( 1 ) 11696 - 11696 2017.9

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

The glomerulus exercises its filtration barrier function by establishing a complex filtration apparatus consisting of podocyte foot processes, glomerular basement membrane and endothelial cells. Disruption of any component of the glomerular filtration barrier leads to glomerular dysfunction, frequently manifested as proteinuria. Ultrastructural studies of the glomerulus by transmission electron microscopy (TEM) and conventional scanning electron microscopy (SEM) have been routinely used to identify and classify various glomerular diseases. Here we report the application of newly developed helium ion scanning microscopy (HIM) to examine the glomerulopathy in a Col4a3 mutant/Alport syndrome mouse model. Our study revealed unprecedented details of glomerular abnormalities in Col4a3 mutants including distorted podocyte cell bodies and disorganized primary processes. Strikingly, we observed abundant filamentous microprojections arising from podocyte cell bodies and processes, and presence of unique bridging processes that connect the primary processes and foot processes in Alport mice. Furthermore, we detected an altered glomerular endothelium with disrupted sub-endothelial integrity. More importantly, we were able to clearly visualize the complex, three-dimensional podocyte and endothelial interface by HIM. Our study demonstrates that HIM provides nanometer resolution to uncover and rediscover critical ultrastructural characteristics of the glomerulopathy in Col4a3 mutant mice.

DOI： 10.1038/s41598-017-12064-5

Ezrin directly interacts with AQP2 and promotes its endocytosis. Reviewed International journal

Wei Li, William W Jin, Kenji Tsuji, Ying Chen, Naohiro Nomura, Limin Su, Naofumi Yui, Julian Arthur, Susanna Cotecchia, Teodor G Paunescu, Dennis Brown, Hua A J Lu

Journal of cell science 130 ( 17 ) 2914 - 2925 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：COMPANY OF BIOLOGISTS LTD

The water channel aquaporin-2 (AQP2) is a major regulator of water homeostasis in response to vasopressin (VP). Dynamic trafficking of AQP2 relies on its close interaction with trafficking machinery proteins and the actin cytoskeleton. Here, we report the identification of ezrin, an actin-binding protein from the ezrin/radixin/moesin (ERM) family as an AQP2-interacting protein. Ezrin was first detected in a co-immunoprecipitation (co-IP) complex using an anti-AQP2 antibody in a proteomic analysis. Immunofluorescence staining revealed the co-expression of ezrin and AQP2 in collecting duct principal cells, and VP treatment caused redistribution of both proteins to the apical membrane. The ezrin-AQP2 interaction was confirmed by co-IP experiments with an anti-ezrin antibody, and by pulldown assays using purified full-length and FERM domain-containing recombinant ezrin. By using purified recombinant proteins, we showed that ezrin directly interacts with AQP2 C-terminus through its N-terminal FERM domain. Knocking down ezrin expression with shRNA resulted in increased membrane accumulation of AQP2 and reduced AQP2 endocytosis. Therefore, through direct interaction with AQP2, ezrin facilitates AQP2 endocytosis, thus linking the dynamic actin cytoskeleton network with AQP2 trafficking.

DOI： 10.1242/jcs.204842

Re-characterization of the Glomerulopathy in CD2AP Deficient Mice by High-Resolution Helium Ion Scanning Microscopy. Reviewed International journal

Kenji Tsuji, Teodor G Păunescu, Hani Suleiman, Dongping Xie, Fahmy A Mamuya, Jeffrey H Miner, Hua A Jenny Lu

Scientific reports 7 ( 1 ) 8321 - 8321 2017.8

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

Helium ion scanning microscopy (HIM) is a novel technology that directly visualizes the cell surface ultrastructure without surface coating. Despite its very high resolution, it has not been applied extensively to study biological or pathology samples. Here we report the application of this powerful technology to examine the three-dimensional ultrastructural characteristics of proteinuric glomerulopathy in mice with CD2-associated protein (CD2AP) deficiency. HIM revealed the serial alteration of glomerular features including effacement and disorganization of the slit diaphragm, followed by foot process disappearance, flattening and fusion of major processes, and eventual transformation into a podocyte sheet as the disease progressed. The number and size of the filtration slit pores decreased. Strikingly, numerous "bleb" shaped microprojections were observed extending from podocyte processes and cell body, indicating significant membrane dynamics accompanying CD2AP deficiency. Visualizing the glomerular endothelium and podocyte-endothelium interface revealed the presence of endothelial damage, and disrupted podocyte and endothelial integrity in 6 week-old Cd2ap-KO mice. We used the HIM technology to investigate at nanometer scale resolution the ultrastructural alterations of the glomerular filtration apparatus in mice lacking the critical slit diaphragm-associated protein CD2AP, highlighting the great potential of HIM to provide new insights into the biology and (patho)physiology of glomerular diseases.

DOI： 10.1038/s41598-017-08304-3

The level of urinary semaphorin3A is associated with disease activity in patients with minimal change nephrotic syndrome. Reviewed International journal

Akiko Inoue-Torii, Shinji Kitamura, Jun Wada, Kenji Tsuji, Hirofumi Makino

International journal of nephrology and renovascular disease 10 167 - 174 2017

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

Semaphorin3A is a secreted protein known to be involved in organogenesis, immune responses and cancer. In the kidney, semaphorin3A is expressed in the glomerular podocytes, distal tubules and collecting tubules, and believed to play a role in the regulation of the kidney development and function. We examined the serum and urinary semaphorin3A levels in 72 patients with renal disease and 5 healthy volunteers. The patients had been diagnosed with thin basement membrane disease (n=4), minimal change nephrotic syndrome (MCNS; n=22), IgA nephritis (n=21), membranous nephropathy (n=16) and focal segmental glomerular sclerosis (n=9). The level of urinary semaphorin3A in MCNS patients tended to be relatively high among all disease groups. We also investigated the urinary semaphorin3A level in 7 patients with MCNS from disease onset to remission during the drug therapy. MCNS patients in pre-remission states had higher urinary semaphorin3A levels than those in post-remission states receiving immunosuppressive therapies. These results suggested that the urinary semaphorin3A level correlates with the MCNS activity. Semaphorin3A has the potential as a biomarker for MCNS to clarify the reactivity for therapy and may be useful in examining other glomerular diseases with proteinuria as well.

DOI： 10.2147/IJNRD.S132980

Trophic Factors from Tissue Stem Cells for Renal Regeneration. Reviewed International journal

Kenji Tsuji, Shinji Kitamura

Stem cells international 2015 537204 - 537204 2015

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

Stem cell therapies against renal injury have been advancing. The many trials for renal regeneration are reported to be effective in many kinds of renal injury models. Regarding the therapeutic mechanism, it is believed that stem cells contribute to make regeneration via not only direct stem cell differentiation in the injured space but also indirect effect via secreted factors from stem cells. Direct differentiation from stem cells to renal composed cells has been reported. They differentiate to renal composed cells and make functions. However, regarding renal regeneration, stem cells are discussed to secrete many kinds of growth factors, cytokines, and chemokines in paracrine or autocrine manner, which protect against renal injury, too. In addition, it is reported that stem cells have the ability to communicate with nearby cells via microvesicle-related RNA and proteins. Taken together from many reports, many secreted factors from stem cells were needed for renal regeneration orchestrally with harmony. In this review, we focused on the effects and insights of stem cells and regenerative factors from stem cells.

DOI： 10.1155/2015/537204

Hypoxia-inducible factor 1α regulates branching morphogenesis during kidney development. Reviewed International journal

Kenji Tsuji, Shinji Kitamura, Hirofumi Makino

Biochemical and biophysical research communications 447 ( 1 ) 108 - 14 2014.4

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

The kidneys are exposed to hypoxic conditions during development. Hypoxia-inducible factor (HIF), an important mediator of the response to hypoxia, is believed to have an important role in development. However, the relationship between HIF and branching morphogenesis has not been elucidated clearly. In this study, we examined whether HIF regulates kidney development. We harvested kidneys from day 13 rat embryos (E13Ks) and cultured the organs under normoxic (20% O2/5% CO2) or hypoxic (5% O2/5% CO2) conditions. We evaluated the kidneys based on morphology and gene expression. E13Ks cultured under hypoxic conditions had significantly more ureteric bud (UB) branching than the E13Ks cultured under normoxic conditions. In addition, the mRNA levels of GDNF and GDNF receptor (GFR-α1), increased under hypoxic conditions in E13Ks. When we cultured E13Ks with the HIF-1α inhibitor digoxin or with siRNA targeting HIF-1α under hypoxic conditions, we did not observe increased UB branching. In addition, the expression of GDNF and GFR-α1 was inhibited under hypoxic conditions when the kidneys were treated with siRNA targeting HIF-1α. We also elucidated that hypoxia inhibited UB cell apoptosis and promoted the expression of FGF7 mRNA levels in metanephric mesenchymal (MM) cells in vitro. These findings suggest that hypoxic condition has important roles in inducing branching morphogenesis during kidney development. Hypoxia might mediate branching morphogenesis via not only GDNF/Ret but also FGF signaling pathway.

DOI： 10.1016/j.bbrc.2014.03.111

The selection of peritoneal mesothelial cells is important for cell therapy to prevent peritoneal fibrosis. Reviewed International journal

Shinji Kitamura, Naoya Horimoto, Kenji Tsuji, Akiko Inoue, Keiichi Takiue, Hitoshi Sugiyama, Hirofumi Makino

Tissue engineering. Part A 20 ( 3-4 ) 529 - 39 2014.2

Language：English Publishing type：Research paper (scientific journal) Publisher：MARY ANN LIEBERT, INC

Long-term peritoneal dialysis (PD) causes chronic peritoneal damage. Peritoneal mesothelial cells (PMCs) play an important role in peritoneal function. We investigated the possibility of cell therapy using the PMCs to prevent peritoneal damage in PD patients. We harvested human PMCs from the PD effluent of PD patients. The PMCs were separated based on morphological characteristics into epithelial-like (Epi) cells and fibroblast-like (Fib) cells by the limiting dilution method. We transplanted these cells into nude mice whose parietal and visceral peritoneum were scratched by mechanical scraping. The transplanted cells were detected at the parietal and visceral peritoneum. Compared with the positive control, the Epi cell therapy group showed very few adhesions and exhibited no thickening of the parietal and visceral peritoneum. However, the group with Fib cell therapy could not inhibit peritoneal adhesion and thickening. In addition, hepatocyte growth factor was expressed by the grafted Epi cells but not Fib cells. Fib cells expressed vascular endothelial growth factor stronger than Epi cells. These two types of cells from the same patient showed different characteristics and effects for cell therapy. These findings suggest that the PMCs from the PD patient showed different characteristics, such as Epi cells and Fib cells, and the selection of PMCs is important for cell therapy on the point of not only the direct cellular interactions but also cytokine secretion from the grafted cells. Furthermore, the differences in the morphological cell characteristics may influence their role in peritoneal regeneration.

DOI： 10.1089/ten.TEA.2013.0130

Mizoribine inhibits the proliferation of renal stem/progenitor cells by G1/S arrest during renal regeneration. Reviewed

Naoya Horimoto, Shinji Kitamura, Kenji Tsuji, Hirofumi Makino

Acta medica Okayama 68 ( 1 ) 7 - 15 2014

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

Immunosuppressive agents are generally administered to treat kidney diseases. However, it is unclear whether renal stem/progenitor cells are directly affected by the immunosuppressive agents. We used normal rat kidney cells, ureteric bud cells and rat kidney stem/progenitor cells in this study. Mizoribine (MZR), cyclophosphamide (CPA) and cyclosporine (CyA) were added to the culture media of these cells. We evaluated the effects of these immunosuppressive agents on cell proliferation using an electrical cell-substrate impedance sensing system (ECIS) and their effects on the process of renal regeneration using the ischemia-reperfusion (I/R) injury rat model. The ECIS data showed that proliferation of each of the 3 types of cells was significantly suppressed by MZR. MZR treatment enhanced renal tubular injury in ischemia-reperfusion (I/R) injured rats, and significantly decreased levels of M-phase cells and Nestin-positive cells. These results suggested that MZR inhibits the cell cycle of renal stem/progenitor cells;thus, physicians should take note that MZR might affect not only inflammation but also renal regeneration.

DOI： 10.18926/AMO/52138

Membranous nephropathy with acquired factor V inhibitor: a case report. Reviewed International journal

Shinji Kitamura, Mahito Misawa, Sayaka Namba, Kenji Tsuji, Rikako Torigoe, Midori Shima, Hirofumi Makino

BMC research notes 6 553 - 553 2013.12

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

BACKGROUND: Membranous nephropathy is one of the most common causes of nephrotic syndrome in adults. In contrast, acquired factor V inhibitor is a rare bleeding disorder. CASE PRESENTATION: A 62-year-old Asian man with a history of cerebral hemorrhage, purpura, eosinophilia and hyper immunoglobulin E syndrome developed proteinuria. The bleeding disorder was diagnosed with acquired factor V inhibitors. A renal biopsy revealed that he suffered from membranous nephropathy with glomerular endothelial damage which is reported to be involved in another factor disorder. After the steroid administration, the coagulation test and proteinuria were improved. CONCLUSIONS: The presence of factor V inhibitors may have been involved in the development of membranous nephropathy.

DOI： 10.1186/1756-0500-6-553

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