1
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Xia J, Huang Y, Ma M, Liu F, Cao B. Downregulating lncRNA MIAT attenuates apoptosis of podocytes exposed to high glucose. Acta Diabetol 2024; 61:451-460. [PMID: 38072843 DOI: 10.1007/s00592-023-02213-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 11/08/2023] [Indexed: 03/27/2024]
Abstract
AIMS Diabetic nephropathy (DN), a destructive complication of diabetes mellitus (DM), is one of the leading causes of end-stage renal disease (ESRD). This study aimed to investigate the role of long non-coding RNA (lncRNA) MIAT in high-glucose (HG)-induced podocyte injury associated with DN. METHODS Three human kidney podocyte (HKP) cultures were treated with HG to mimic DN. Expression of lncRNA MIAT, podocyte-specific and injury-related proteins, and apoptosis were assessed before and after MIAT knockdown using MIAT shRNAs. RESULTS MIAT expression was upregulated in HKPs in response to glucose stress. HG treatment resulted in a significant increase in the apoptotic rate, Bax level, and levels of injury-related proteins desmin, fibroblast-specific protein 1 (FSP-1), and smooth muscle α-actin (α-SMA), and a significant reduction in Bcl-2 levels and the levels of podocyte-specific proteins synaptopodin and podocin. Transfection of HKPs with shRNAs significantly reduced MIAT levels (p < 0.05) and attenuated apoptosis in HG-medium. Correspondingly, the levels of synaptopodin and podocin were upregulated, and desmin, FSP-1, and α-SMA were reduced (p < 0.05). Western blot analysis also showed that anti-apoptotic active caspase-3 and Bax and proapoptotic Bcl-2 were elevated and decreased, respectively, after MIAT knockdown, suggesting that apoptosis pathways are deactivated after MIAT downregulation. CONCLUSIONS High glucose upregulates MIAT level in HKPs and induces cellular injury. Knockdown of MIAT alleviates the injury likely via deactivating apoptosis pathways.
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Affiliation(s)
- Jiayi Xia
- Department of Endocrinology, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, 550001, Guizhou, China
| | - Yan Huang
- Department of Medical Insurance, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, 550001, Guizhou, China
| | - Min Ma
- Department of Gynecology, Graduate School of Guizhou, University of Traditional Chinese Medicine, Guiyang, 550001, Guizhou, China
| | - Fang Liu
- Department of Coloproctology, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, 550001, Guizhou, China.
| | - Bo Cao
- Department of Coloproctology, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, 550001, Guizhou, China.
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Abstract
Rho family GTPases are molecular switches best known for their pivotal role in dynamic regulation of the actin cytoskeleton, but also of cellular morphology, motility, adhesion and proliferation. The prototypic members of this family (RhoA, Rac1 and Cdc42) also contribute to the normal kidney function and play important roles in the structure and function of various kidney cells including tubular epithelial cells, mesangial cells and podocytes. The kidney's vital filtration function depends on the structural integrity of the glomerulus, the proximal portion of the nephron. Within the glomerulus, the architecturally actin-based cytoskeleton podocyte forms the final cellular barrier to filtration. The glomerulus appears as a highly dynamic signalling hub that is capable of integrating intracellular cues from its individual structural components. Dynamic regulation of the podocyte cytoskeleton is required for efficient barrier function of the kidney. As master regulators of actin cytoskeletal dynamics, Rho GTPases are therefore of critical importance for sustained kidney barrier function. Dysregulated activities of the Rho GTPases and of their effectors are implicated in the pathogenesis of both hereditary and idiopathic forms of kidney diseases. Diabetic nephropathy is a progressive kidney disease that is caused by injury to kidney glomeruli. High glucose activates RhoA/Rho-kinase in mesangial cells, leading to excessive extracellular matrix production (glomerulosclerosis). This RhoA/Rho-kinase pathway also seems involved in the post-transplant hypertension frequently observed during treatment with calcineurin inhibitors, whereas Rac1 activation was observed in post-transplant ischaemic acute kidney injury.
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Affiliation(s)
- Clara Steichen
- Inserm UMR-1082 Irtomit, Poitiers, France,Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France
| | - Claude Hervé
- Inserm UMR-1082 Irtomit, Poitiers, France,CONTACT Claude HervéInserm UMR-1082 Irtomit, Poitiers, France
| | - Thierry Hauet
- Inserm UMR-1082 Irtomit, Poitiers, France,Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France,Department of Medical Biology, Service De Biochimie, CHU De Poitiers, Poitiers, France
| | - Nicolas Bourmeyster
- Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France,Department of Medical Biology, Service De Biochimie, CHU De Poitiers, Poitiers, France,Laboratoire STIM CNRS ERL 7003, Université de Poitiers, Poitiers Cédex, France
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3
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Audzeyenka I, Rogacka D, Rachubik P, Typiak M, Rychłowski M, Angielski S, Piwkowska A. The PKGIα-Rac1 pathway is a novel regulator of insulin-dependent glucose uptake in cultured rat podocytes. J Cell Physiol 2021; 236:4655-4668. [PMID: 33244808 DOI: 10.1002/jcp.30188] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 11/09/2022]
Abstract
Insulin plays a major role in regulating glucose homeostasis in podocytes. Protein kinase G type Iα (PKGIα) plays an important role in regulating glucose uptake in these cells. Rac1 signaling plays an essential role in the reorganization of the actin cytoskeleton and is also essential for insulin-stimulated glucose transport. The experiments were conducted using primary rat podocytes. We performed western blot analysis, evaluated small GTPases activity assays, measured radioactive glucose uptake, and performed immunofluorescence imaging to analyze the role of PKGIα-Rac1 signaling in regulating podocyte function. We also utilized a small-interfering RNA-mediated approach to determine the role of PKGIα and Rac1 in regulating glucose uptake in podocytes. The present study investigated the influence of the PKGI pathway on the insulin-dependent regulation of activity and cellular localization of small guanosine triphosphatases in podocytes. We found that the PKGIα-dependent activation of Rac1 signaling induced activation of the PAK/cofilin pathway and increased insulin-mediated glucose uptake in podocytes. The downregulation of PKGIα or Rac1 expression abolished this effect. Rac1 silencing prevented actin remodeling and GLUT4 translocation close to the cell membrane. These data provide evidence that PKGIα-dependent activation of the Rac1 signaling pathways is a novel regulator of insulin-mediated glucose uptake in cultured rat podocytes.
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Affiliation(s)
- Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
| | - Marlena Typiak
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
| | - Michał Rychłowski
- Laboratory of Virus Molecular Biology, University of Gdańsk, Intercollegiate Faculty of Biotechnology, Medical University of Gdańsk, , Gdańsk, Poland
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
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4
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Chenxu G, Shaoyu Z, Lili L, Dai X, Kuang Q, Qiang L, Linfeng H, Deshuai L, Jun T, Minxuan X. Betacyanins attenuates diabetic nephropathy in mice by inhibiting fibrosis and oxidative stress via the improvement of Nrf2 signaling. J Funct Foods 2021. [DOI: 10.1016/j.jff.2021.104403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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5
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Qi C, Alsomali F, Zhong J, Harris RC, Kon V, Yang H, Fogo AB. Increased dishevelled associated activator of morphogenesis 2, a new podocyte-associated protein, in diabetic nephropathy. Nephrol Dial Transplant 2021; 36:1006-1016. [PMID: 33544843 DOI: 10.1093/ndt/gfab014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 01/05/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Previously, by using proteomic analysis and RNA sequencing in isolated glomeruli, we identified several novel differentially expressed proteins in human and mouse diabetic nephropathy (DN) versus controls, including dishevelled associated activator of morphogenesis 2 (DAAM2). DAAM2 binds the Wnt effector Dvl. We aimed to study possible contributions of DAAM2 to DN. METHODS We assessed DAAM2 by immunostaining in non-cancer regions of human nephrectomy (Nx), DN and normal donor kidney tissues. We also examined DAAM2 in DN mice (db/db eNOS-/-) and Nx mice. DN mice treated with angiotensin-converting enzyme inhibitor (ACEI), dipeptidyl peptidase 4 inhibitor (DPP4I) or vehicle were compared. DAAM2 was knocked down in primary cultured podocytes by small interfering RNA to study its effects on cell function. RESULTS In normal human glomeruli, DAAM2 was expressed only on podocytes. DAAM2 expression was increased in both Nx and DN versus normal donors. Podocyte DAAM2 expression was increased in DN and Nx mouse models. Glomerular DAAM2 expression correlated with glomerular size and was decreased significantly by ACEI while DPP4I only numerically reduced DAAM2. In primary cultured podocytes, knockdown of DAAM2 enhanced adhesion, slowed migration, activated Wnt-β-catenin signaling and downregulated mammalian target of rapamycin complex 1 (mTORC1) and Rho activity. CONCLUSIONS Podocyte DAAM2 is upregulated in both Nx and DN, which could be contributed to by glomerular hypertrophy. We hypothesize that DAAM2 regulates podocyte function through the mTORC1, Wnt/β-catenin and Rho signaling pathways.
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Affiliation(s)
- Chenyang Qi
- Department of Pathology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Faten Alsomali
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Jinyong Zhong
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Raymond C Harris
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Valentina Kon
- Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Haichun Yang
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Agnes B Fogo
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
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6
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Differential organ-specific inflammatory response to progranulin in high-fat diet-fed mice. Sci Rep 2021; 11:1194. [PMID: 33441916 PMCID: PMC7806827 DOI: 10.1038/s41598-020-80940-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 12/22/2020] [Indexed: 01/30/2023] Open
Abstract
Progranulin (PGRN) has been reported to bind tumor necrosis factor (TNF) receptor and to inhibit TNFα signaling. We evaluated the effect of augmentation of TNFα signaling by PGRN deficiency on the progression of kidney injury. Eight-week-old PGRN knockout (KO) and wild-type (WT) mice were fed a standard diet or high-fat diet (HFD) for 12 weeks. Albuminuria, markers of tubular damage, and renal mRNA levels of inflammatory cytokines were higher in HFD-fed KO (KO-HFD) mice than in HFD-fed WT (WT-HFD) mice. Body weight, vacuolization in proximal tubules, and systemic and adipose tissue inflammatory markers were lower in the KO-HFD mice than in the WT-HFD mice. The renal megalin expression was lower in the KO mice than in the WT mice regardless of the diet type. The megalin expression was also reduced in mouse proximal tubule epithelial cells stimulated with TNFα and in those with PGRN knockdown by small interfering RNA in vitro. PGRN deficiency was associated with both exacerbated renal inflammation and decreased systemic inflammation, including that in the adipose tissue of mice with HFD-induced obesity. Improved tubular vacuolization in the KO-HFD mice might partially be explained by the decreased expression of megalin in proximal tubules.
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7
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Wang X, Yang XL, Liu KC, Sheng WL, Xia Q, Wang RC, Chen XQ, Zhang Y. Effects of streptozotocin on pancreatic islet β-cell apoptosis and glucose metabolism in zebrafish larvae. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:1025-1038. [PMID: 31993854 DOI: 10.1007/s10695-020-00769-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
Type 1 diabetes is characterized by an increase in blood glucose levels resulting from damage to β cells in pancreatic islets and the consequent absolute insufficiency of insulin. Animal models of type 1 diabetes were usually established using drugs toxic to β cells, such as streptozotocin (STZ). To assess the application of zebrafish larvae in diabetes research, we explore the effects of STZ on pancreatic islets and glucose metabolism in zebrafish larvae. STZ was microinjected into the pericardial cavity of zebrafish larvae on alternate days for three times. At 2 days after the whole series of STZ injection (12 dpf), free-glucose level in larvae tissue shows a significant increase, and the fluorescence signal in immunohistochemistry, which indicates the insulin expression, was significantly weaker compared with the solution-injected control. Obvious apoptosis signals were also observed in the location of pancreatic islet, and insulin content decreased to be undetectable in STZ-injected larvae. Gene expression level of ins decreased to half of the solution injection control and that of casp3a was upregulated by 2.20-fold. Expression level of glut2 and gck decreased to 0.312-fold and 0.093-fold, respectively. pck1 was upregulated by 2.533-fold in STZ-injected larvae. By tracking detection, we found the free-glucose level in STZ-injected larvae gradually approached the level of the solution injection control and the insulin content recovered at 6 days post-STZ injection (16 dpf). Consistent with the change of the glucose level, the regeneration rate of the caudal fin in the STZ-injected group decreased initially, but recovered and accelerated gradually finally at 8 days post-amputation (20 dpf). These results indicate the generation of a transient hyperglycemia model due to β-cell apoptosis caused by STZ, which is abated by the vigorous regeneration ability of β cells in zebrafish larvae.
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Affiliation(s)
- Xue Wang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Xue-Liang Yang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Ke-Chun Liu
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Wen-Long Sheng
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Qing Xia
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Rong-Chun Wang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Xi-Qiang Chen
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China
| | - Yun Zhang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), 28789 Jingshidong Road, Licheng District, Jinan, 250103, Shandong Province, People's Republic of China.
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Jinan, 250103, Shandong Province, China.
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8
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Ichikawa S, Gohda T, Murakoshi M, Li Z, Adachi E, Koshida T, Suzuki Y. Aspartic acid supplementation ameliorates symptoms of diabetic kidney disease in mice. FEBS Open Bio 2020; 10:1122-1134. [PMID: 32301275 PMCID: PMC7262904 DOI: 10.1002/2211-5463.12862] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 03/31/2020] [Accepted: 04/13/2020] [Indexed: 12/23/2022] Open
Abstract
Diabetic kidney disease (DKD) is among the most common and serious complications of both type 1 and type 2 diabetes. In this study, we used KK/Ta‐Ins2Akita (KK‐Akita) mice as a model of DKD and KK/Ta (KK) mice as controls to identify novel factors related to the development/progression of DKD. Capillary electrophoresis coupled with mass spectrometry analysis revealed that circulating Asp (l‐aspartic acid) levels in diabetic KK‐Akita mice tend to be lower than those in control KK mice. Therefore, we evaluated the effect of Asp supplementation to prevent the progression of DKD in KK‐Akita mice. Mice were divided into three groups: (a) untreated KK mice (Control group), (b) untreated KK‐Akita mice (DKD group), and (c) treated (double‐volume Asp diet) KK‐Akita mice (Tx group). Kidney sections were stained with fluorescein isothiocyanate‐labeled lectins, wheat germ agglutinin (WGA), and anti‐endothelial nitric oxide synthase (eNOS) antibody for evaluation of endothelial surface layer (ESL) and NO synthesis. The mesangial area and glomerular size in the DKD group were significantly larger than those in the Control group; however, there was no significant difference in those between the DKD and Tx groups. Albuminuria, the ratio of foot process effacement, and thickness of glomerular basement membrane in the Tx group were significantly lower than those in the DKD group. Furthermore, the expression levels of glomerular WGA and microvascular eNOS in the Tx group improved significantly and approached the level in the Control group. In conclusion, the improvement of albuminuria in the Tx group may be caused by the reduction of oxidative stress in the kidneys, which may lead to the subsequent improvement of glomerular ESL.
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Affiliation(s)
- Saki Ichikawa
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Tomohito Gohda
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Maki Murakoshi
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Zi Li
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Eri Adachi
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Takeo Koshida
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Yusuke Suzuki
- Department of Nephrology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
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9
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Yu SMW, Nissaisorakarn P, Husain I, Jim B. Proteinuric Kidney Diseases: A Podocyte's Slit Diaphragm and Cytoskeleton Approach. Front Med (Lausanne) 2018; 5:221. [PMID: 30255020 PMCID: PMC6141722 DOI: 10.3389/fmed.2018.00221] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/18/2018] [Indexed: 01/19/2023] Open
Abstract
Proteinuric kidney diseases are a group of disorders with diverse pathological mechanisms associated with significant losses of protein in the urine. The glomerular filtration barrier (GFB), comprised of the three important layers, the fenestrated glomerular endothelium, the glomerular basement membrane (GBM), and the podocyte, dictates that disruption of any one of these structures should lead to proteinuric disease. Podocytes, in particular, have long been considered as the final gatekeeper of the GFB. This specialized visceral epithelial cell contains a complex framework of cytoskeletons forming foot processes and mediate important cell signaling to maintain podocyte health. In this review, we will focus on slit diaphragm proteins such as nephrin, podocin, TRPC6/5, as well as cytoskeletal proteins Rho/small GTPases and synaptopodin and their respective roles in participating in the pathogenesis of proteinuric kidney diseases. Furthermore, we will summarize the potential therapeutic options targeting the podocyte to treat this group of kidney diseases.
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Affiliation(s)
- Samuel Mon-Wei Yu
- Department of Medicine, Jacobi Medical Center, Bronx, NY, United States
| | | | - Irma Husain
- Department of Medicine, James J. Peters VA Medical Center, Bronx, NY, United States
| | - Belinda Jim
- Department of Medicine, Jacobi Medical Center, Bronx, NY, United States.,Renal Division, Jacobi Medical Center, Bronx, NY, United States
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10
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Rac1 in podocytes promotes glomerular repair and limits the formation of sclerosis. Sci Rep 2018; 8:5061. [PMID: 29567961 PMCID: PMC5864960 DOI: 10.1038/s41598-018-23278-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 03/06/2018] [Indexed: 02/06/2023] Open
Abstract
Rac1, a Rho family member, is ubiquitously expressed and participates in various biological processes. Rac1 expression is induced early in podocyte injury, but its role in repair is unclear. To investigate the role of Rac1 expression in podocytes under pathological conditions, we used podocyte-specific Rac1 conditional knock-out (cKO) mice administered adriamycin (ADR), which causes nephrosis and glomerulosclerosis. Larger areas of detached podocytes, more adhesion of the GBM to Bowman’s capsule, and a higher ratio of sclerotic glomeruli were observed in Rac1 cKO mice than in control mice, whereas no differences were observed in glomerular podocyte numbers in both groups after ADR treatment. The mammalian target of rapamycin (mTOR) pathway, which regulates the cell size, was more strongly suppressed in the podocytes of Rac1 cKO mice than in those of control mice under pathological conditions. In accordance with this result, the volumes of podocytes in Rac1 cKO mice were significantly reduced compared with those of control mice. Experiments using in vitro ADR-administered Rac1 knockdown podocytes also supported that a reduction in Rac1 suppressed mTOR activity in injured podocytes. Taken together, these data indicate that Rac1-associated mTOR activation in podocytes plays an important role in preventing the kidneys from developing glomerulosclerosis.
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11
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Shirata N, Ihara KI, Yamamoto-Nonaka K, Seki T, Makino SI, Oliva Trejo JA, Miyake T, Yamada H, Campbell KN, Nakagawa T, Mori K, Yanagita M, Mundel P, Nishimori K, Asanuma K. Glomerulosclerosis Induced by Deficiency of Membrane-Associated Guanylate Kinase Inverted 2 in Kidney Podocytes. J Am Soc Nephrol 2017; 28:2654-2669. [PMID: 28539383 DOI: 10.1681/asn.2016121356] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/03/2017] [Indexed: 11/03/2022] Open
Abstract
Membrane-associated guanylate kinase inverted 2 (MAGI-2) is a component of the slit diaphragm (SD) of glomerular podocytes. Here, we investigated the podocyte-specific function of MAGI-2 using newly generated podocyte-specific MAGI-2-knockout (MAGI-2-KO) mice. Compared with podocytes from wild-type mice, podocytes from MAGI-2-KO mice exhibited SD disruption, morphologic abnormalities of foot processes, and podocyte apoptosis leading to podocyte loss. These pathologic changes manifested as massive albuminuria by 8 weeks of age and glomerulosclerosis and significantly higher plasma creatinine levels at 12 weeks of age; all MAGI-2-KO mice died by 20 weeks of age. Loss of MAGI-2 in podocytes associated with decreased expression and nuclear translocation of dendrin, which is also a component of the SD complex. Dendrin translocates from the SD to the nucleus of injured podocytes, promoting apoptosis. Our coimmunoprecipitation and in vitro reconstitution studies showed that dendrin is phosphorylated by Fyn and dephosphorylated by PTP1B, and that Fyn-induced phosphorylation prevents Nedd4-2-mediated ubiquitination of dendrin. Under physiologic conditions in vivo, phosphorylated dendrin localized at the SDs; in the absence of MAGI-2, dephosphorylated dendrin accumulated in the nucleus. Furthermore, induction of experimental GN in rats led to the downregulation of MAGI-2 expression and the nuclear accumulation of dendrin in podocytes. In summary, MAGI-2 and Fyn protect dendrin from Nedd4-2-mediated ubiquitination and from nuclear translocation, thereby maintaining the physiologic homeostasis of podocytes, and the lack of MAGI-2 in podocytes results in FSGS.
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Affiliation(s)
- Naritoshi Shirata
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Toda, Japan
| | - Kan-Ichiro Ihara
- The Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kanae Yamamoto-Nonaka
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Takuto Seki
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Shin-Ichi Makino
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Juan Alejandro Oliva Trejo
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takafumi Miyake
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Yamada
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kirk Nicholas Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Takahiko Nakagawa
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kiyoshi Mori
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Peter Mundel
- Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts
| | - Katsuhiko Nishimori
- The Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Katsuhiko Asanuma
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan; .,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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12
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Dai H, Liu Q, Liu B. Research Progress on Mechanism of Podocyte Depletion in Diabetic Nephropathy. J Diabetes Res 2017; 2017:2615286. [PMID: 28791309 PMCID: PMC5534294 DOI: 10.1155/2017/2615286] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/05/2017] [Accepted: 03/05/2017] [Indexed: 12/13/2022] Open
Abstract
Diabetic nephropathy (DN) together with glomerular hyperfiltration has been implicated in the development of diabetic microangiopathy in the initial stage of diabetic diseases. Increased amounts of urinary protein in DN may be associated with functional and morphological alterations of podocyte, mainly including podocyte hypertrophy, epithelial-mesenchymal transdifferentiation (EMT), podocyte detachment, and podocyte apoptosis. Accumulating studies have revealed that disruption in multiple renal signaling pathways had been critical in the progression of these pathological damages, such as adenosine monophosphate-activated kinase signaling pathways (AMPK), wnt/β-catenin signaling pathways, endoplasmic reticulum stress-related signaling pathways, mammalian target of rapamycin (mTOR)/autophagy pathway, and Rho GTPases. In this review, we highlight new molecular insights underlying podocyte injury in the progression of DN, which offer new therapeutic targets to develop important renoprotective treatments for DN over the next decade.
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Affiliation(s)
- Haoran Dai
- Department of Nephrology, Shunyi Branch, Beijing Hospital of Traditional Chinese Medicine, Station East 5, Shunyi District, Beijing 101300, China
| | - Qingquan Liu
- Department of Nephrology, Shunyi Branch, Beijing Hospital of Traditional Chinese Medicine, Station East 5, Shunyi District, Beijing 101300, China
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
- *Qingquan Liu: and
| | - Baoli Liu
- Department of Nephrology, Shunyi Branch, Beijing Hospital of Traditional Chinese Medicine, Station East 5, Shunyi District, Beijing 101300, China
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
- *Baoli Liu:
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13
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Sharma KR, Heckler K, Stoll SJ, Hillebrands JL, Kynast K, Herpel E, Porubsky S, Elger M, Hadaschik B, Bieback K, Hammes HP, Nawroth PP, Kroll J. ELMO1 protects renal structure and ultrafiltration in kidney development and under diabetic conditions. Sci Rep 2016; 6:37172. [PMID: 27849017 PMCID: PMC5111104 DOI: 10.1038/srep37172] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/25/2016] [Indexed: 12/24/2022] Open
Abstract
Engulfment and cell motility 1 (ELMO1) functions as a guanine exchange factor for Rac1 and was recently found to protect endothelial cells from apoptosis. Genome wide association studies suggest that polymorphisms within human elmo1 act as a potential contributing factor for the development of diabetic nephropathy. Yet, the function of ELMO1 with respect to the glomerulus and how this protein contributes to renal pathology was unknown. Thus, this study aimed to identify the role played by ELMO1 in renal development in zebrafish, under hyperglycaemic conditions, and in diabetic nephropathy patients. In zebrafish, hyperglycaemia did not alter renal ELMO1 expression. However, hyperglycaemia leads to pathophysiological and functional alterations within the pronephros, which could be rescued via ELMO1 overexpression. Zebrafish ELMO1 crispants exhibited a renal pathophysiology due to increased apoptosis which could be rescued by the inhibition of apoptosis. In human samples, immunohistochemical staining of ELMO1 in nondiabetic, diabetic and polycystic kidneys localized ELMO1 in glomerular podocytes and in the tubules. However, ELMO1 was not specifically or distinctly regulated under either one of the disease conditions. Collectively, these results highlight ELMO1 as an important factor for glomerular protection and renal cell survival via decreasing apoptosis, especially under diabetic conditions.
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Affiliation(s)
- Krishna Rakesh Sharma
- Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Karl Heckler
- Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sandra J Stoll
- Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg, Germany
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology, Division of Pathology, University Medical Center Groningen, Groningen, The Netherlands
| | - Katharina Kynast
- Institute of Pathology, Heidelberg University, Heidelberg, Germany
| | - Esther Herpel
- Institute of Pathology, Heidelberg University, Heidelberg, Germany.,Tissue Bank of the National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Stefan Porubsky
- Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Marlies Elger
- Institue of Neuroanatomy, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Boris Hadaschik
- Department of Urology, Heidelberg University Hospital, Heidelberg, Germany
| | - Karen Bieback
- Institute of Transfusion Medicine and Immunology and FlowCore Manneim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Hans-Peter Hammes
- Fifth Medical Department, University Medical Centre Mannheim, Mannheim, Germany
| | - Peter P Nawroth
- Department of Medicine I and Clinical Chemistry, Heidelberg University, Heidelberg, Germany
| | - Jens Kroll
- Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg, Germany
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14
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Liu W, Yang Y, Liu Y, Lu X, Guo S, Wu M, Wang M, Yan L, Wang Q, Zhao X, Tong X, Hu J, Li Y, Hu R, Stanton RC, Zhang Z. Exogenous kallikrein protects against diabetic nephropathy. Kidney Int 2016; 90:1023-1036. [PMID: 27546607 DOI: 10.1016/j.kint.2016.06.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 06/13/2016] [Accepted: 06/16/2016] [Indexed: 01/06/2023]
Abstract
The kallikrein-kinin system has been shown to be involved in the development of diabetic nephropathy, but specific mechanisms are not fully understood. Here, we determined the renal-protective role of exogenous pancreatic kallikrein in diabetic mice and studied potential mechanisms in db/db type 2 diabetic and streptozotocin-induced type 1 diabetic mice. After the onset of diabetes, mice were treated with either pancreatic kallikrein (db/db+kallikrein, streptozotocin+kallikrein) or saline (db/db+saline, streptozotocin+saline) for 16 weeks, while another group of streptozotocin-induced diabetic mice received the same treatment after onset of albuminuria (streptozotocin'+kallikrein, streptozotocin'+saline). Db/m littermates or wild type mice were used as non-diabetic controls. Pancreatic kallikrein had no effects on body weight, blood glucose and blood pressure, but significantly reduced albuminuria among all three groups. Pathological analysis showed that exogenous kallikrein decreased the thickness of the glomerular basement membrane, protected against the effacement of foot process, the loss of endothelial fenestrae, and prevented the loss of podocytes in diabetic mice. Renal fibrosis, inflammation and oxidative stress were reduced in kallikrein-treated mice compared to diabetic controls. The expression of kininogen1, tissue kallikrein, kinin B1 and B2 receptors were all increased in the kallikrein-treated compared to saline-treated mice. Thus, exogenous pancreatic kallikrein both prevented and ameliorated diabetic nephropathy, which may be mediated by activating the kallikrein-kinin system.
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Affiliation(s)
- Wenjuan Liu
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Yeping Yang
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Yemei Liu
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China; Department of Endocrinology, The Second People's Hospital, Wuhu, Anhui, China
| | - Xiaolan Lu
- Department of Endocrinology, High-tech District People's Hospital, Suzhou, Jiangsu, China
| | - Shizhe Guo
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Meng Wu
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, Jiangsu, China
| | - Meng Wang
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, Jiangsu, China
| | - Linling Yan
- Department of Endocrinology, The First People's Hospital of Taichang, Jiangsu, China
| | - Qinghua Wang
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China; Institute of Endocrinology and Diabetology, Fudan University, Shanghai, China; Division of Endocrinology and Metabolism, Keenan Research Centre at the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada; Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Xiaolong Zhao
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Xian Tong
- Jiangsu (Qianhong) Engineering Research Center for Innovative Biological Drugs, Changzhou, Jiangsu, China
| | - Ji Hu
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, Jiangsu, China
| | - Yiming Li
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China; Institute of Endocrinology and Diabetology, Fudan University, Shanghai, China
| | - Renming Hu
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China; Institute of Endocrinology and Diabetology, Fudan University, Shanghai, China
| | - Robert C Stanton
- Renal Division, Joslin Diabetes Center, Boston, Massachusetts, USA
| | - Zhaoyun Zhang
- Division of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China; Institute of Endocrinology and Diabetology, Fudan University, Shanghai, China.
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15
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Abstract
Podocytes are highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule. When it comes to glomerular filtration, podocytes play an active role in preventing plasma proteins from entering the urinary ultrafiltrate by providing a barrier comprising filtration slits between foot processes, which in aggregate represent a dynamic network of cellular extensions. Foot processes interdigitate with foot processes from adjacent podocytes and form a network of narrow and rather uniform gaps. The fenestrated endothelial cells retain blood cells but permit passage of small solutes and an overlying basement membrane less permeable to macromolecules, in particular to albumin. The cytoskeletal dynamics and structural plasticity of podocytes as well as the signaling between each of these distinct layers are essential for an efficient glomerular filtration and thus for proper renal function. The genetic or acquired impairment of podocytes may lead to foot process effacement (podocyte fusion or retraction), a morphological hallmark of proteinuric renal diseases. Here, we briefly discuss aspects of a contemporary view of podocytes in glomerular filtration, the patterns of structural changes in podocytes associated with common glomerular diseases, and the current state of basic and clinical research.
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Affiliation(s)
- Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
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