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Arif E, Solanki AK, Rahman B, Wolf B, Schnellmann RG, Nihalani D, Lipschutz JH. Role of the β 2-adrenergic receptor in podocyte injury and recovery. Pharmacol Rep 2024; 76:612-621. [PMID: 38668812 PMCID: PMC11126448 DOI: 10.1007/s43440-024-00594-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 03/28/2024] [Accepted: 04/03/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND Podocytes have a remarkable ability to recover from injury; however, little is known about the recovery mechanisms involved in this process. We recently showed that formoterol, a long-acting β2-adrenergic receptor (β2-AR) agonist, induced mitochondrial biogenesis (MB) in podocytes and led to renoprotection in mice. However, it is not clear whether this effect was mediated by formoterol acting through the β2-AR or if it occurred through "off-target" effects. METHODS We genetically deleted the β2-AR specifically in murine podocytes and used these mice to determine whether formoterol acting through the podocyte β2-AR alone is sufficient for recovery of renal filtration function following injury. The podocyte-specific β2-AR knockout mice (β2-ARfl/fl/PodCre) were generated by crossing β2-AR floxed mice with podocin Cre (B6.Cg-Tg(NPHS2-cre)295Lbh/J) mice. These mice were then subjected to both acute and chronic glomerular injury using nephrotoxic serum (NTS) and adriamycin (ADR), respectively. The extent of injury was evaluated by measuring albuminuria and histological and immunostaining analysis of the murine kidney sections. RESULTS A similar level of injury was observed in β2-AR knockout and control mice; however, the β2-ARfl/fl/PodCre mice failed to recover in response to formoterol. Functional evaluation of the β2-ARfl/fl/PodCre mice following injury plus formoterol showed similar albuminuria and glomerular injury to control mice that were not treated with formoterol. CONCLUSIONS These results indicate that the podocyte β2-AR is a critical component of the recovery mechanism and may serve as a novel therapeutic target for treating podocytopathies.
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Affiliation(s)
- Ehtesham Arif
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Clinical Science Building 822N, 96 Jonathan Lucas Street, Charleston, SC, 29425, USA
| | - Ashish K Solanki
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Clinical Science Building 822N, 96 Jonathan Lucas Street, Charleston, SC, 29425, USA
| | - Bushra Rahman
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Clinical Science Building 822N, 96 Jonathan Lucas Street, Charleston, SC, 29425, USA
| | - Bethany Wolf
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Rick G Schnellmann
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA
- Southern Arizona VA Health Care System, Tucson, AZ, USA
| | - Deepak Nihalani
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Clinical Science Building 822N, 96 Jonathan Lucas Street, Charleston, SC, 29425, USA
| | - Joshua H Lipschutz
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Clinical Science Building 822N, 96 Jonathan Lucas Street, Charleston, SC, 29425, USA.
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Liu PJ, Sayeeda K, Zhuang C, Krendel M. Roles of myosin 1e and the actin cytoskeleton in kidney functions and familial kidney disease. Cytoskeleton (Hoboken) 2024. [PMID: 38708443 DOI: 10.1002/cm.21861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/21/2024] [Accepted: 04/04/2024] [Indexed: 05/07/2024]
Abstract
Mammalian kidneys are responsible for removing metabolic waste and maintaining fluid and electrolyte homeostasis via selective filtration. One of the proteins closely linked to selective renal filtration is myosin 1e (Myo1e), an actin-dependent molecular motor found in the specialized kidney epithelial cells involved in the assembly and maintenance of the renal filter. Point mutations in the gene encoding Myo1e, MYO1E, have been linked to familial kidney disease, and Myo1e knockout in mice leads to the disruption of selective filtration. In this review, we discuss the role of the actin cytoskeleton in renal filtration, the known and hypothesized functions of Myo1e, and the possible explanations for the impact of MYO1E mutations on renal function.
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Affiliation(s)
- Pei-Ju Liu
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Kazi Sayeeda
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Cindy Zhuang
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Mira Krendel
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA
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3
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Waller AP, Wolfgang KJ, Pruner I, Stevenson ZS, Abdelghani E, Muralidharan K, Wilkie TK, Blissett AR, Calomeni EP, Vetter TA, Brodsky SV, Smoyer WE, Nieman MT, Kerlin BA. Prothrombin Knockdown Protects Podocytes and Reduces Proteinuria in Glomerular Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.20.544360. [PMID: 38464017 PMCID: PMC10925217 DOI: 10.1101/2023.06.20.544360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Chronic kidney disease (CKD) is a leading cause of death, and its progression is driven by glomerular podocyte injury and loss, manifesting as proteinuria. Proteinuria includes urinary loss of coagulation zymogens, cofactors, and inhibitors. Importantly, both CKD and proteinuria significantly increase the risk of thromboembolic disease. Prior studies demonstrated that anticoagulants reduced proteinuria in rats and that thrombin injured cultured podocytes. Herein we aimed to directly determine the influence of circulating prothrombin on glomerular pathobiology. We hypothesized that (pro)thrombin drives podocytopathy, podocytopenia, and proteinuria. Glomerular proteinuria was induced with puromycin aminonucleoside (PAN) in Wistar rats. Circulating prothrombin was either knocked down using a rat-specific antisense oligonucleotide or elevated by serial intravenous infusions of prothrombin protein, which are previously established methods to model hypo- (LoPT) and hyper-prothrombinemia (HiPT), respectively. After 10 days (peak proteinuria in this model) plasma prothrombin levels were determined, kidneys were examined for (pro)thrombin co-localization to podocytes, histology, and electron microscopy. Podocytopathy and podocytopenia were determined and proteinuria, and plasma albumin were measured. LoPT significantly reduced prothrombin colocalization to podocytes, podocytopathy, and proteinuria with improved plasma albumin. In contrast, HiPT significantly increased podocytopathy and proteinuria. Podocytopenia was significantly reduced in LoPT vs. HiPT rats. In summary, prothrombin knockdown ameliorated PAN-induced glomerular disease whereas hyper-prothrombinemia exacerbated disease. Thus, (pro)thrombin antagonism may be a viable strategy to simultaneously provide thromboprophylaxis and prevent podocytopathy-mediated CKD progression.
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Hu S, Hang X, Wei Y, Wang H, Zhang L, Zhao L. Crosstalk among podocytes, glomerular endothelial cells and mesangial cells in diabetic kidney disease: an updated review. Cell Commun Signal 2024; 22:136. [PMID: 38374141 PMCID: PMC10875896 DOI: 10.1186/s12964-024-01502-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 01/28/2024] [Indexed: 02/21/2024] Open
Abstract
Diabetic kidney disease (DKD) is a long-term and serious complication of diabetes that affects millions of people worldwide. It is characterized by proteinuria, glomerular damage, and renal fibrosis, leading to end-stage renal disease, and the pathogenesis is complex and involves multiple cellular and molecular mechanisms. Among three kinds of intraglomerular cells including podocytes, glomerular endothelial cells (GECs) and mesangial cells (MCs), the alterations in one cell type can produce changes in the others. The cell-to-cell crosstalk plays a crucial role in maintaining the glomerular filtration barrier (GFB) and homeostasis. In this review, we summarized the recent advances in understanding the pathological changes and interactions of these three types of cells in DKD and then focused on the signaling pathways and factors that mediate the crosstalk, such as angiopoietins, vascular endothelial growth factors, transforming growth factor-β, Krüppel-like factors, retinoic acid receptor response protein 1 and exosomes, etc. Furthermore, we also simply introduce the application of the latest technologies in studying cell interactions within glomerular cells and new promising mediators for cell crosstalk in DKD. In conclusion, this review provides a comprehensive and updated overview of the glomerular crosstalk in DKD and highlights its importance for the development of novel intervention approaches.
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Affiliation(s)
- Shiwan Hu
- Institute of Metabolic Diseases, Guang' anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Xing Hang
- Institute of Metabolic Diseases, Guang' anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Yu Wei
- Institute of Metabolic Diseases, Guang' anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Han Wang
- Beijing University of Chinese Medicine, Beijing, 100029, China.
| | - Lili Zhang
- Institute of Metabolic Diseases, Guang' anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China.
| | - Linhua Zhao
- Institute of Metabolic Diseases, Guang' anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China.
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5
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Ma S, Qiu Y, Zhang C. Cytoskeleton Rearrangement in Podocytopathies: An Update. Int J Mol Sci 2024; 25:647. [PMID: 38203817 PMCID: PMC10779434 DOI: 10.3390/ijms25010647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/14/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Podocyte injury can disrupt the glomerular filtration barrier (GFB), leading to podocytopathies that emphasize podocytes as the glomerulus's key organizer. The coordinated cytoskeleton is essential for supporting the elegant structure and complete functions of podocytes. Therefore, cytoskeleton rearrangement is closely related to the pathogenesis of podocytopathies. In podocytopathies, the rearrangement of the cytoskeleton refers to significant alterations in a string of slit diaphragm (SD) and focal adhesion proteins such as the signaling node nephrin, calcium influx via transient receptor potential channel 6 (TRPC6), and regulation of the Rho family, eventually leading to the disorganization of the original cytoskeletal architecture. Thus, it is imperative to focus on these proteins and signaling pathways to probe the cytoskeleton rearrangement in podocytopathies. In this review, we describe podocytopathies and the podocyte cytoskeleton, then discuss the molecular mechanisms involved in cytoskeleton rearrangement in podocytopathies and summarize the effects of currently existing drugs on regulating the podocyte cytoskeleton.
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Affiliation(s)
| | | | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (S.M.); (Y.Q.)
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Treadmill Exercise Training Ameliorates Functional and Structural Age-Associated Kidney Changes in Male Albino Rats. ScientificWorldJournal 2021; 2021:1393372. [PMID: 34887703 PMCID: PMC8651424 DOI: 10.1155/2021/1393372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 11/10/2021] [Indexed: 12/28/2022] Open
Abstract
Aging is a biological process that impacts multiple organs. Unfortunately, kidney aging affects the quality of life with high mortality rate. So, searching for innovative nonpharmacological modality improving age-associated kidney deterioration is important. This study aimed to throw more light on the beneficial effect of treadmill exercise on the aged kidney. Thirty male albino rats were divided into three groups: young (3-4 months old), sedentary aged (23-24 months old), and exercised aged (23-24 months old, practiced moderate-intensity treadmill exercise 5 days/week for 8 weeks). The results showed marked structural alterations in the aged kidney with concomitant impairment of kidney functions and increase in arterial blood pressure with no significant difference in kidney weight. Also, it revealed that treadmill exercise alleviated theses effects in exercised aged group with reduction of urea and cystatin C. Exercise training significantly decreased glomerulosclerosis index, tubular injury score, and % area of collagen deposition. Treadmill exercise exerted its beneficial role via a significant reduction of C-reactive protein and malondialdehyde and increase in total antioxidant capacity. In addition, exercise training significantly decreased desmin immunoreaction and increased aquaporin-3, vascular endothelial growth factor, and beclin-1 in the aged kidney. This study clarified that treadmill exercise exerted its effects via antioxidant and anti-inflammatory mechanisms, podocyte protection, improving aquaporin-3 and vascular endothelial growth factor expression, and inducing autophagy in the aged kidney. This work provided a new insight into the promising role of aerobic exercise to ameliorate age-associated kidney damage.
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Wang Y, Tian J, Mi Y, Ren X, Lian S, Kang J, Wang J, Zang H, Wu Z, Yang J, Qiao X, Zhou X, Wang G, Zhou Y, Li R. Experimental study on renoprotective effect of intermedin on diabetic nephropathy. Mol Cell Endocrinol 2021; 528:111224. [PMID: 33675865 DOI: 10.1016/j.mce.2021.111224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 01/17/2021] [Accepted: 01/23/2021] [Indexed: 12/16/2022]
Abstract
Intermedin(IMD) is a novel member of the calcitonin/calcitonin gene-related peptide (CT/CGRP) family that has anti-inflammatory, antioxidant and anti-apoptosis properties. This study aimed to evaluate the renoprotective effects of IMD on podocyte apoptotic loss and slit diaphragm protein deficiency the kidneys of rats with in streptozotocin (STZ) induced diabetes in high glucose-exposed podocytes. Our results showed that IMD significantly attenuated proteinuria, and alleviated the abnormal alterations in glomerular ultrastructure in vivo. IMD also improved the induction of slit diaphragm proteins, and restored the decreased Bcl-2 expression and suppressed Bax and caspase-3 induction in the diabetic glomeruli. In addition, IMD attenuated podocyte apoptosis and filamentous actin (F-actin) rearrangement in high glucose-exposed podocytes. Exposure to high glucose elevated the unfolded protein response (UPR) to endoplasmic reticulum (ER) stress in renal podocytes, and IMD treatment blocked such ER stress responses pertinent to podocyte apoptosis and reduced synthesis of slit diaphragm proteins in vivo and in vitro. These observations demonstrate that targeting ER stress is an underlying mechanism of IMD-mediated amelioration of diabetes-associated podocyte injury and dysfunction.
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Affiliation(s)
- Yanhong Wang
- Department of Nephrology, Postdoctoral Workstation of Shanxi Provincial People's Hospital, The Affiliated People's Hospital of Shanxi Medical University, Shanxi Kidney Disease Institute, Taiyuan, Shanxi, 030012, China; Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Jihua Tian
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Yang Mi
- Department of Urology, The Affiliated Bethune Hospital of Shanxi Medical University, Shanxi Bethune Hospital (Shanxi Academy of Medical Sciences), Taiyuan, Shanxi, 030032, China
| | - Xiaojun Ren
- Department of Nephrology, The Affiliated Bethune Hospital of Shanxi Medical University, Shanxi Bethune Hospital (Shanxi Academy of Medical Sciences), Taiyuan, Shanxi, 030032, China
| | - Shizhong Lian
- Department of Neurosurgery, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Jing Kang
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Juanjuan Wang
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Haojing Zang
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Zhijing Wu
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Jia Yang
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Xi Qiao
- Department of Nephrology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Xiaoshuang Zhou
- Department of Nephrology, Postdoctoral Workstation of Shanxi Provincial People's Hospital, The Affiliated People's Hospital of Shanxi Medical University, Shanxi Kidney Disease Institute, Taiyuan, Shanxi, 030012, China
| | - Guiqin Wang
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, 030001, China
| | - Yun Zhou
- Department of Nephrology, Postdoctoral Workstation of Shanxi Provincial People's Hospital, The Affiliated People's Hospital of Shanxi Medical University, Shanxi Kidney Disease Institute, Taiyuan, Shanxi, 030012, China.
| | - Rongshan Li
- Department of Nephrology, Postdoctoral Workstation of Shanxi Provincial People's Hospital, The Affiliated People's Hospital of Shanxi Medical University, Shanxi Kidney Disease Institute, Taiyuan, Shanxi, 030012, China.
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8
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Role of Rho GTPase Interacting Proteins in Subcellular Compartments of Podocytes. Int J Mol Sci 2021; 22:ijms22073656. [PMID: 33915776 PMCID: PMC8037304 DOI: 10.3390/ijms22073656] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/22/2021] [Accepted: 03/26/2021] [Indexed: 01/15/2023] Open
Abstract
The first step of urine formation is the selective filtration of the plasma into the urinary space at the kidney structure called the glomerulus. The filtration barrier of the glomerulus allows blood cells and large proteins such as albumin to be retained while eliminating the waste products of the body. The filtration barrier consists of three layers: fenestrated endothelial cells, glomerular basement membrane, and podocytes. Podocytes are specialized epithelial cells featured by numerous, actin-based projections called foot processes. Proteins on the foot process membrane are connected to the well-organized intracellular actin network. The Rho family of small GTPases (Rho GTPases) act as intracellular molecular switches. They tightly regulate actin dynamics and subsequent diverse cellular functions such as adhesion, migration, and spreading. Previous studies using podocyte-specific transgenic or knockout animal models have established that Rho GTPases are crucial for the podocyte health and barrier function. However, little attention has been paid regarding subcellular locations where distinct Rho GTPases contribute to specific functions. In the current review, we discuss cellular events involving the prototypical Rho GTPases (RhoA, Rac1, and Cdc42) in podocytes, with particular focus on the subcellular compartments where the signaling events occur. We also provide our synthesized views of the current understanding and propose future research directions.
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Chen A, Feng Y, Lai H, Ju W, Li Z, Li Y, Wang A, Hong Q, Zhong F, Wei C, Fu J, Guan T, Liu B, Kretzler M, Lee K, He JC. Soluble RARRES1 induces podocyte apoptosis to promote glomerular disease progression. J Clin Invest 2020; 130:5523-5535. [PMID: 32634130 PMCID: PMC7524479 DOI: 10.1172/jci140155] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/01/2020] [Indexed: 12/18/2022] Open
Abstract
Using the Nephrotic Syndrome Study Network Consortium data set and other publicly available transcriptomic data sets, we identified retinoic acid receptor responder protein 1 (RARRES1) as a gene whose expression positively correlated with renal function decline in human glomerular disease. The glomerular expression of RARRES1, which is largely restricted to podocytes, increased in focal segmental glomerulosclerosis (FSGS) and diabetic kidney disease (DKD). TNF-α was a potent inducer of RARRES1 expression in cultured podocytes, and transcriptomic analysis showed the enrichment of cell death pathway genes with RARRES1 overexpression. The overexpression of RARRES1 indeed induced podocyte apoptosis in vitro. Notably, this effect was dependent on its cleavage in the extracellular domain, as the mutation of its cleavage site abolished the apoptotic effect. Mechanistically, the soluble RARRES1 was endocytosed and interacted with and inhibited RIO kinase 1 (RIOK1), resulting in p53 activation and podocyte apoptosis. In mice, podocyte-specific overexpression of RARRES1 resulted in marked glomerular injury and albuminuria, while the overexpression of RARRES1 cleavage mutant had no effect. Conversely, podocyte-specific knockdown of Rarres1 in mice ameliorated glomerular injury in the setting of adriamycin-induced nephropathy. Our study demonstrates an important role and the mechanism of RARRES1 in podocyte injury in glomerular disease.
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Affiliation(s)
- Anqun Chen
- Division of Nephrology, Zhongshan Hospital, Xiamen University, Xiamen, China
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Ye Feng
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Nephrology, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
| | - Han Lai
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Wenjun Ju
- Division of Nephrology, Department of Internal Medicine, Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA
| | - Zhengzhe Li
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Yu Li
- Division of Nephrology, Zhongshan Hospital, Xiamen University, Xiamen, China
| | - Andrew Wang
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Quan Hong
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Fang Zhong
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Chengguo Wei
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jia Fu
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Tianjun Guan
- Division of Nephrology, Zhongshan Hospital, Xiamen University, Xiamen, China
| | - Bichen Liu
- Department of Nephrology, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
| | - Matthias Kretzler
- Division of Nephrology, Department of Internal Medicine, Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA
| | - Kyung Lee
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John Cijiang He
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Renal Section, James J. Peters VA Medical Center, Bronx, New York, USA
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Zheng J, Zhang S, Chen H, Cai X, Zhang C, Li S, Zhou Y, Shang J, Liang S, Yao F. Protosappanin-A and oleanolic acid protect injured podocytes from apoptosis through inhibition of AKT-mTOR signaling. Cell Biol Int 2020; 44:189-199. [PMID: 31441181 PMCID: PMC6973098 DOI: 10.1002/cbin.11218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 08/18/2019] [Indexed: 01/24/2023]
Abstract
Protosappanin-A (PrA) and oleanolic acid (OA), which are important effective ingredients isolated from Caesalpinia sappan L., exhibit therapeutic potential in multiple diseases. This study focused on exploring the mechanisms of PrA and OA function in podocyte injury. An in vitro model of podocyte injury was induced by the sC5b-9 complex and assays such as cell viability, apoptosis, immunofluorescence, quantitative real-time polymerase chain reaction, and western blot were performed to further investigate the effects and mechanisms of PrA and OA in podocyte injury. The models of podocyte injury were verified to be successful as seen through significantly decreased levels of nephrin, podocin, and CD2AP and increased level of desmin. The sC5b-9-induced podocyte apoptosis was inhibited in injured podocytes treated with PrA and OA, accompanied by increased protein levels of nephrin, podocin, CD2AP, and Bcl2 and decreased levels of desmin and Bax. The p-AKT/p-mTOR levels were also reduced by treatment of PrA and OA while AKT/mTOR was unaltered. Further, the effects of PrA and OA on injured podocytes were similar to that of LY294002 (a PI3K-AKT inhibitor). PrA and OA were also seen to inhibit podocyte apoptosis and p-AKT/p-mTOR levels induced by IGF-1 (a PI3K-AKT activator). Our data demonstrate that PrA and OA can protect podocytes from injury or apoptosis, which may occur through inhibition of the abnormal activation of AKT-mTOR signaling.
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Affiliation(s)
- Jiaxin Zheng
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Shoulin Zhang
- Department of NephrologyThe Affiliated Hospital to Changchun University of Chinese MedicineChangchunJilin130021PR China
| | - Huijun Chen
- Department of CardiologyThe Second Hospital Affiliated Heilongjiang University of Traditional Chinese MedicineHarbinHeilongjiang150009PR China
| | - Xiaojun Cai
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Chunjian Zhang
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Shuhua Li
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Yabin Zhou
- Department of CardiologyThe First Hospital Affiliated Heilongjiang University of Traditional Chinese MedicineHarbinHeilongjiang150040PR China
| | - Jing Shang
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Shunyu Liang
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Fengzhen Yao
- Department of NephrologyHeilongjiang University of Traditional Chinese MedicineHarbinHeilongjiang150040PR China
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11
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tRNA-derived fragments (tRFs) contribute to podocyte differentiation. Biochem Biophys Res Commun 2019; 521:1-8. [PMID: 31629473 DOI: 10.1016/j.bbrc.2019.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/01/2019] [Accepted: 09/04/2019] [Indexed: 11/21/2022]
Abstract
Loss of glomerular podocytes is the crucial event in the progression of chronic kidney disease (CKD). tRNA-derived fragments (tRFs), a newfangled branch of small non-coding RNA (sncRNA), recently reported to play a vital part in several diseases. In present study, we aimed to detect and reveal the role of tRFs in podocyte differentiation. The expression levels of tRFs between undifferentiated and differentiated podocytes were sequenced by illumina nextseq 500, and further verified by quantitative RT-PCR. 69 upregulated and 70 downregulated tRFs in total were singled out (Fold change > 2, P < 0.05). Gene ontology (GO) analysis indicated they are involved in the biological processes of transcription, DNA-templated, positive regulation of transcription from RNA polymerase II promoter, angiogenesis, cell adhesion. Besides, KEGG analysis suggested that these differentially tRFs are associated with PI3K-Akt signaling pathway, Rap1 signaling pathway, Ras signaling pathway, MAPK signaling pathway, and Wnt signaling pathway. Therefore, the differentially tRFs might regulate the differentiation of podocyte and the process of CKD. The functions and mechanisms of tRFs in podocytes are needed to be further explored.
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12
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He S, Liu X, Lin Z, Liu Y, Gu L, Zhou H, Tang W, Zuo J. Reversible SAHH inhibitor protects against glomerulonephritis in lupus-prone mice by downregulating renal α-actinin-4 expression and stabilizing integrin-cytoskeleton linkage. Arthritis Res Ther 2019; 21:40. [PMID: 30696480 PMCID: PMC6352376 DOI: 10.1186/s13075-019-1820-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/11/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Glomerulonephritis is one of the major complications and causes of death in systemic lupus erythematosus (SLE) and is characterized by glomerulosclerosis, interstitial fibrosis, and tubular atrophy, along with severe persistent proteinuria. DZ2002 is a reversible S-adenosyl-L-homocysteine hydrolase (SAHH) inhibitor with potent therapeutic activity against lupus nephritis in mice. However, the molecular events underlying the renal protective effects of DZ2002 remained unclear. This study is designed to uncover the molecular mechanisms of DZ2002 on glomerulonephritis of lupus-prone mice. METHODS We conducted a twice-daily treatment of DZ2002 on the lupus-prone NZB/WF1 mice, and the progression of lupus nephritis and alteration of renal function were monitored. The LC-MS-based label-free quantitative (LFQ) proteomic approach was applied to analyze the kidney tissue samples from the normal C57BL/6 mice and the NZB/WF1 mice treated with DZ2002 or vehicle. KEGG pathway enrichment and direct protein-protein interaction (PPI) network analyses were used to map the pathways in which the significantly changed proteins (SCPs) are involved. The selected proteins from proteomic analysis were validated by Western blot analysis and immunohistochemistry in the kidney tissues. RESULTS The twice-daily regimen of DZ2002 administration significantly ameliorated the lupus nephritis and improved the renal function in NZB/WF1 mice. A total of 3275 proteins were quantified, of which 253 proteins were significantly changed across normal C57BL/6 mice and the NZB/WF1 mice treated with DZ2002 or vehicle. Pathway analysis revealed that 13 SCPs were involved in tight junction and focal adhesion process. Further protein expression validation demonstrated that DZ2002-treated NZB/WF1 mice exhibited downregulation of α-actinin-4 and integrin-linked kinase (ILK), as well as the restoration of β1-integrin activation in the kidney tissues compared with the vehicle-treated ones. CONCLUSIONS Our study demonstrated the first evidence for the molecular mechanism of SAHH inhibitor on glomerulonephritis in SLE via the modulation of α-actinin-4 expression and focal adhesion-associated signaling proteins in the kidney.
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Affiliation(s)
- Shijun He
- Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, China
| | - Xing Liu
- Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Zemin Lin
- Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yuting Liu
- Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, China
| | - Lei Gu
- Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Hu Zhou
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, China. .,Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
| | - Wei Tang
- Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, China.
| | - Jianping Zuo
- Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, China.
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13
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Wang X, Gao Y, Tian N, Zou D, Shi Y, Zhang N. Astragaloside IV improves renal function and fibrosis via inhibition of miR-21-induced podocyte dedifferentiation and mesangial cell activation in diabetic mice. DRUG DESIGN DEVELOPMENT AND THERAPY 2018; 12:2431-2442. [PMID: 30122901 PMCID: PMC6084069 DOI: 10.2147/dddt.s170840] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background Podocyte dedifferentiation and mesangial cell (MC) activation play an important role in many glomerular diseases associated with fibrosis. MicroRNA-21 (miR-21) is closely linked to renal fibrosis, but it is unknown whether and how miR-21 promotes podocyte dedifferentiation and MC activation and whether astragaloside IV (AS-IV) improves renal function and fibrosis through the regulation of miR-21. Materials and methods Cultured MCs, primary mouse podocytes, and diabetic KK-Ay mice were treated with AS-IV. Cell transfection, Western blot, real-time PCR, immunofluorescence assay, immunohistochemical assay, and electronic microscopy were used to detect the markers of podocyte dedifferentiation and MC activation and to observe the renal morphology. Results Our data showed that miR-21 expression was increased and that AS-IV decreased miR-21 levels in cells, serum, and kidney. Overexpressed miR-21 promoted podocyte dedifferentiation and MC activation, and treatment with AS-IV reversed this effect. Furthermore, the overexpression of miR-21 activated the β-catenin pathway and the transforming growth factor (TGF)-β1/Smads pathway in the process of podocyte dedifferentiation and MC activation, which was abolished by AS-IV treatment. In addition, both the Wnt/β-catenin pathway inhibitor XAV-939 and the TGF-β1/Smads pathway inhibitor SB431542 reversed the effect of AS-IV. Furthermore, AS-IV improved renal function and fibrosis in diabetic KK-Ay mice. Conclusion Our results indicated that AS-IV ameliorates renal function and renal fibrosis by inhibiting miR-21 overexpression-induced podocyte dedifferentiation and MC activation in diabetic kidney disease. These findings pave way for future studies investigating AS-IV as a potential therapeutic agent in the management of glomerular diseases.
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Affiliation(s)
- Xiaolei Wang
- Department of Endocrinology, School of Traditional Chinese Medicine, Capital Medical University, Beijing, China, .,Department of Endocrinology, Beijing Key Laboratory of Traditional Chinese Medicine Collateral Disease Theory Research, Beijing, China,
| | - Yanbin Gao
- Department of Endocrinology, School of Traditional Chinese Medicine, Capital Medical University, Beijing, China, .,Department of Endocrinology, Beijing Key Laboratory of Traditional Chinese Medicine Collateral Disease Theory Research, Beijing, China,
| | - Nianxiu Tian
- Department of Endocrinology, School of Traditional Chinese Medicine, Capital Medical University, Beijing, China,
| | - Dawei Zou
- Department of Endocrinology, Beijing Key Laboratory of Traditional Chinese Medicine Collateral Disease Theory Research, Beijing, China,
| | - Yimin Shi
- Department of Endocrinology, School of Traditional Chinese Medicine, Capital Medical University, Beijing, China,
| | - Nan Zhang
- Department of Endocrinology, School of Traditional Chinese Medicine, Capital Medical University, Beijing, China, .,Department of Endocrinology, Beijing Key Laboratory of Traditional Chinese Medicine Collateral Disease Theory Research, Beijing, China,
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14
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Cardoso VG, Gonçalves GL, Costa-Pessoa JM, Thieme K, Lins BB, Casare FAM, de Ponte MC, Camara NOS, Oliveira-Souza M. Angiotensin II-induced podocyte apoptosis is mediated by endoplasmic reticulum stress/PKC-δ/p38 MAPK pathway activation and trough increased Na +/H + exchanger isoform 1 activity. BMC Nephrol 2018; 19:179. [PMID: 30005635 PMCID: PMC6043975 DOI: 10.1186/s12882-018-0968-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 06/26/2018] [Indexed: 11/12/2022] Open
Abstract
Background Angiotensin II (Ang II) contributes to the progression of renal diseases associated with proteinuria and glomerulosclerosis mainly by inducing podocyte apoptosis. In the present study, we investigated whether the chronic effects of Ang II via AT1 receptor (AT1R) would result in endoplasmic reticulum (ER) stress/PKC-delta/p38 MAPK stimulation, and consequently podocyte apoptosis. Methods Wistar rats were treated with Ang II (200 ng·kg−1·min−1, 42 days) and or losartan (10 mg·kg−1·day−1, 14 days). Immortalized mouse podocyte were treated with 1 μM Ang II and/or losartan (1 μM) or SB203580 (0.1 μM) (AT1 receptor antagonist and p38 MAPK inhibitor) for 24 h. Kidney sections and cultured podocytes were used to evaluate protein expression by immunofluorescence and immunoblotting. Apoptosis was evaluated by flow cytometry and intracellular pH (pHi) was analyzed using microscopy combined with the fluorescent probe BCECF/AM. Results Compared with controls, Ang II via AT1R increased chaperone GRP 78/Bip protein expression in rat glomeruli (p < 0.001) as well as in podocyte culture (p < 0.01); increased phosphorylated eIf2-α (p < 0.05), PKC-delta (p < 0.01) and p38 MAPK (p < 0.001) protein expression. Furthermore, Ang II induced p38 MAPK-mediated late apoptosis and increased the Bax/Bcl-2 ratio (p < 0.001). Simultaneously, Ang II via AT1R induced p38 MAPK-NHE1-mediated increase of pHi recovery rate after acid loading. Conclusion Together, our results indicate that Ang II-induced podocyte apoptosis is associated with AT1R/ER stress/PKC-delta/p38 MAPK axis and enhanced NHE1-mediated pHi recovery rate.
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Affiliation(s)
- Vanessa Gerolde Cardoso
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil
| | - Guilherme Lopes Gonçalves
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil
| | - Juliana Martins Costa-Pessoa
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil
| | - Karina Thieme
- Laboratory of Carbohydrates and Radioimmunoassays (LIM-18), Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | - Bruna Bezerra Lins
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil
| | - Fernando Augusto Malavazzi Casare
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil
| | - Mariana Charleaux de Ponte
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil
| | - Niels Olsen Saraiva Camara
- Laboratory for Transplantation Immunobiology, Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Maria Oliveira-Souza
- Laboratory of Renal Physiology, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil.
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15
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Cai X, Wang L, Wang X, Hou F. Silence of IGFBP7 suppresses apoptosis and epithelial mesenchymal transformation of high glucose induced-podocytes. Exp Ther Med 2018; 16:1095-1102. [PMID: 30112052 PMCID: PMC6090473 DOI: 10.3892/etm.2018.6298] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/16/2018] [Indexed: 12/15/2022] Open
Abstract
Insulin-like growth factor-binding protein 7 (IGFBP7) has been identified as a secreted protein associated with a number of cellular processes. However, the specific regulatory mechanisms of IGFBP7 on podocytes of diabetic nephropathy (DN) are yet to be elucidated. In the present study, podocytes were identified initially via an immunofluorescence assay using an anti-synaptopodin antibody. It was subsequently demonstrated that glucose promoted podocyte proliferation in a time- and dose-dependent manner via MTT assay. In addition, IGFBP7 expression was silenced in podocytes via siRNA, the effects of which were evaluated using western blotting and reverse transcription-quantitative polymerase chain reaction. It was demonstrated that silencing IGFBP7 inhibited apoptosis and epithelial mesenchymal transformation (EMT) of podocytes mediated by high glucose (HG). Transforming growth factor (TGF)-β1/mothers against decapentaplegic homolog (Smad) signaling was associated with proliferation, apoptotic activities and EMT. Therefore, the expression levels of TGF-β1/Smad pathway were detected, and it was observed that silencing IGFBP7 suppressed the TGF-β1/Smad pathway in podocytes induced by HG. These findings suggested that IGFBP7 may serve as a potential therapeutic target for DN.
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Affiliation(s)
- Xiaojun Cai
- Department of Endocrinology, Heilongjiang Provincial Academy of Chinese Medical Science, Harbin, Heilongjiang 150036, P.R. China
| | - Lei Wang
- Department of Endocrinology, Heilongjiang Provincial Academy of Chinese Medical Science, Harbin, Heilongjiang 150036, P.R. China
| | - Xuling Wang
- Department of Endocrinology, Heilongjiang Provincial Academy of Chinese Medical Science, Harbin, Heilongjiang 150036, P.R. China
| | - Fengyan Hou
- Department of Endocrinology, Heilongjiang Provincial Academy of Chinese Medical Science, Harbin, Heilongjiang 150036, P.R. China
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16
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Lv Z, Hu M, Fan M, Li X, Lin J, Zhen J, Wang Z, Jin H, Wang R. Podocyte-specific Rac1 deficiency ameliorates podocyte damage and proteinuria in STZ-induced diabetic nephropathy in mice. Cell Death Dis 2018; 9:342. [PMID: 29497040 PMCID: PMC5832796 DOI: 10.1038/s41419-018-0353-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 12/12/2022]
Abstract
Activation of Ras-related C3 botulinum toxin substrate 1 (Rac1) has been implicated in diverse kidney diseases, yet its in vivo significance in diabetic nephropathy (DN) is largely unknown. In the present study, we demonstrated a podocyte-specific Rac1-deficient mouse strain and showed that specific inhibition of Rac1 was able to attenuate diabetic podocyte injury and proteinuria by the blockade of Rac1/PAK1/p38/β-catenin signaling cascade, which reinstated the integrity of podocyte slit diaphragms (SD), rectified the effacement of foot processes (FPs), and prevented the dedifferentiation of podocytes. In vitro, we showed Rac1/PAK1 physically bound to β-catenin and had a direct phosphorylation modification on its C-terminal Ser675, leading to less ubiquitylated β-catenin, namely more stabilized β-catenin, and its nuclear migration under high-glucose conditions; further, p38 activation might be responsible for β-catenin nuclear accumulation via potentiating myocyte-specific enhancer factor 2C (MEF2c) phosphorylation. These findings provided evidence for a potential renoprotective and therapeutic strategy of cell-specific Rac1 deficiency for DN and other proteinuric diseases.
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Affiliation(s)
- Zhimei Lv
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Mengsi Hu
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Minghua Fan
- Department of Obstetrics and Gynecology, The Second Hospital of Shandong University, Jinan, China
| | - Xiaobing Li
- Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, China
| | - Jiangong Lin
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Junhui Zhen
- Department of Pathology, School of Medicine, Shandong University, Jinan, China
| | - Ziyang Wang
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Haijun Jin
- Department of Internal Medicine Clinic, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Rong Wang
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
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17
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Ling L, Tan Z, Zhang C, Gui S, Hu Y, Chen L. Long noncoding RNA ENSRNOG00000037522 is involved in the podocyte epithelial‑mesenchymal transition in diabetic rats. Int J Mol Med 2018; 41:2704-2714. [PMID: 29436579 PMCID: PMC5846646 DOI: 10.3892/ijmm.2018.3457] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/19/2018] [Indexed: 12/30/2022] Open
Abstract
Diabetic nephropathy (DN) is one of the most common complications associated with type I and II diabetes mellitus. Long noncoding RNAs (lncRNAs) have been implicated in various physiological and pathological processes, and recent evidence has demonstrated that they are involved in the process of the epithelial-mesenchymal transition (EMT). In the present study, the potential functions of lncRNA ENSRNOG00000037522 during the EMT process in DN were investigated. The results identified that the level of the lncRNA ENSRNOG00000037522 was significantly increased in kidney tissues collected from rats with streptozocin (STZ)-induced DN accompanied by impairment of the glomerular podocytes. It was further demonstrated that the silencing of lncRNA ENSRNOG00000037522 by small interfering RNA transfection partially restored the podocyte function. In addition, knockdown of lncRNA ENSRNOG00000037522 repaired the damage to the podocytes via regulating vimentin, podocalyxin-like 1 and nephrin expression. In conclusion, the current results demonstrated that lncRNA ENSRNOG00000037522 serves a pivotal role in the podocyte EMT in DN.
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Affiliation(s)
- Li Ling
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Zhen Tan
- Department of Neurosurgery, Shenzhen Children's Hospital, Shenzhen, Guangdong 518026, P.R. China
| | - Changning Zhang
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Shuyan Gui
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Yuanyuan Hu
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Libo Chen
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
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18
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Lewko B, Maryn A, Latawiec E, Daca A, Rybczynska A. Angiotensin II Modulates Podocyte Glucose Transport. Front Endocrinol (Lausanne) 2018; 9:418. [PMID: 30087656 PMCID: PMC6066665 DOI: 10.3389/fendo.2018.00418] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 07/02/2018] [Indexed: 11/27/2022] Open
Abstract
Podocytes play a central role in the maintenance of the glomerular filtration barrier and are cellular targets of angiotensin II (AngII). Non-hemodynamic pathways of AngII signaling regulate cellular function and mediate podocyte abnormalities that are associated with various glomerulopathies, including diabetic kidney disease. In this study we investigated the capacity of AngII to modulate glucose uptake in mouse podocytes expressing the human AT1 receptor (AT1R+) after 5 days of exposure to normal (NG, 5.6 mmol/L) or to high (HG, 30 mmol/L) glucose. Short (30 min) as well as long-term (24 h) incubations with AngII markedly enhanced glucose transport in both NG and HG cells. In podocytes cultured under NG conditions, AngII inhibited insulin-stimulated glucose uptake. Regardless of the presence or absence of AngII, no effect of insulin on glucose uptake was observed in HG cells. Stimulation of glucose transport by AngII was mediated by protein kinase C and by phosphoinositide 3-kinase. Glucose dependent surface expression of the glucose transporters GLUT1, GLUT2, and GLUT4 was modulated by AngII in a time and glucose concentration dependent manner. Furthermore, despite its inhibitory effect on insulin's action, AngII elevated the number of podocyte insulin receptors in both NG and HG cultured cells. These findings demonstrate that AngII modulates podocyte basal, as well as insulin-dependent glucose uptake by regulating glucose transporters and insulin signaling.
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Affiliation(s)
- Barbara Lewko
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
- *Correspondence: Barbara Lewko
| | - Anna Maryn
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
| | - Elzbieta Latawiec
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
| | - Agnieszka Daca
- Department of Pathology and Experimental Rheumatology, Faculty of Medicine, Medical University of Gdansk, Gdańsk, Poland
| | - Apolonia Rybczynska
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
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19
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Abu Hamad R, Berman S, Hachmo Y, Stark M, Hasan F, Doenyas-Barak K, Efrati S. Response of Renal Podocytes to Excessive Hydrostatic Pressure: a Pathophysiologic Cascade in a Malignant Hypertension Model. Kidney Blood Press Res 2017; 42:1104-1118. [PMID: 29224013 DOI: 10.1159/000485774] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 11/28/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Renal injuries induced by increased intra-glomerular pressure coincide with podocyte detachment from the glomerular basement membrane (GBM). In previous studies, it was demonstrated that mesangial cells have a crucial role in the pathogenesis of malignant hypertension. However, the exact pathophysiological cascade responsible for podocyte detachment and its relationship with mesangial cells has not been fully elucidated yet and this was the aim of the current study. METHODS Rat renal mesangial or podocytes were exposed to high hydrostatic pressure in an in-vitro model of malignant hypertension. The resulted effects on podocyte detachment, apoptosis and expression of podocin and integrinβ1 in addition to Angiotensin-II and TGF-β1 generation were evaluated. To simulate the paracrine effect podocytes were placed in mesangial cell media pre-exposed to pressure, or in media enriched with Angiotensin-II, TGF-β1 or receptor blockers. RESULTS High pressure resulted in increased Angiotensin-II levels in mesangial and podocyte cells. Angiotensin-II via the AT1 receptors reduced podocin expression and integrinβ1, culminating in detachment of both viable and apoptotic podocytes. Mesangial cells exposed to pressure had a greater increase in Angiotensin-II than pressure-exposed podocytes. The massively increased concentration of Angiotensin-II by mesangial cells, together with increased TGF-β1 production, resulted in increased apoptosis and detachment of non-viable apoptotic podocytes. Unlike the direct effect of pressure on podocytes, the mesangial mediated effects were not related to changes in adhesion proteins expression. CONCLUSIONS Hypertension induces podocyte detachment by autocrine and paracrine effects. In a direct response to pressure, podocytes increase Angiotensin-II levels. This leads, via AT1 receptors, to structural changes in adhesion proteins, culminating in viable podocyte detachment. Paracrine effects of hypertension, mediated by mesangial cells, lead to higher levels of both Angiotensin-II and TGF-β1, culminating in apoptosis and detachment of non-viable podocytes.
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Affiliation(s)
| | - Sylvia Berman
- Research & Development Unit, Zerifin, Israel.,Nephrology Division, Assaf-Harofeh Medical Center, Zerifin, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Zerifin, Israel
| | | | - Moshe Stark
- Research & Development Unit, Zerifin, Israel
| | - Fadia Hasan
- Research & Development Unit, Zerifin, Israel
| | - Keren Doenyas-Barak
- Nephrology Division, Assaf-Harofeh Medical Center, Zerifin, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Zerifin, Israel
| | - Shai Efrati
- Research & Development Unit, Zerifin, Israel.,Nephrology Division, Assaf-Harofeh Medical Center, Zerifin, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Zerifin, Israel
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20
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Hosoe-Nagai Y, Hidaka T, Sonoda A, Sasaki Y, Yamamoto-Nonaka K, Seki T, Asao R, Tanaka E, Trejo JAO, Kodama F, Takagi M, Tada N, Ueno T, Nishinakamura R, Tomino Y, Asanuma K. Re-expression of Sall1 in podocytes protects against adriamycin-induced nephrosis. J Transl Med 2017; 97:1306-1320. [PMID: 28759006 DOI: 10.1038/labinvest.2017.69] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 04/26/2017] [Accepted: 05/01/2017] [Indexed: 12/12/2022] Open
Abstract
The highly conserved spalt (sal) gene family members encode proteins characterized by multiple double zinc finger motifs of the C2H2 type. Humans and mice each have four known Sal-like genes (SALL1-4 in humans and Sall1-4 in mice). Sall1 is known to have a crucial role in kidney development. To explore the significance of Sall1 in differentiated podocytes, we investigated podocyte-specific Sall1-deficient mice (Sall1 KOp°d°/p°d°) using a podocin-Cre/loxP system and siRNA Sall1 knockdown (Sall1 KD) podocytes. Under physiological conditions, Sall1 KOp°d°/p°d° mice exhibited no proteinuria during their lifetime, but foot-process effacement was detected in some of the podocytes. To elucidate the role of Sall1 in injured podocytes, we used an adriamycin (ADR)-induced model of nephrosis and glomerulosclerosis. Surprisingly, the expression of Sall1 was elevated in control mice on day 14 after ADR injection. On day 28 after ADR injection, Sall1 KOp°d°/p°d° mice exhibited significantly higher levels of proteinuria and higher numbers of sclerotic glomeruli. Differentiated Sall1 KD podocytes showed a loss of synaptopodin, suppressed stress fiber formation, and, ultimately, impaired directed cell migration. In addition, the loss of Sall1 increased the number of apoptotic podocytes following ADR treatment. These results indicated that Sall1 has a protective role in podocytes; thus, we investigated the endoplasmic reticulum stress marker GRP78. GRP78 expression was higher in ADR-treated Sall1 KOp°d°/p°d° mice than in control mice. Sall1 appeared to influence the expression of GRP78 in injured podocytes. These results suggest that Sall1 is associated with actin reorganization, endoplasmic reticulum stress, and apoptosis in injured podocytes. These protective aspects of Sall1 re-expression in injured podocytes may have the potential to reduce apoptosis and possibly glomerulosclerosis.
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Affiliation(s)
- Yoshiko Hosoe-Nagai
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Teruo Hidaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Ayano Sonoda
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Yu Sasaki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Kanae Yamamoto-Nonaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takuto Seki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rin Asao
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Eriko Tanaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Department of Pediatrics, Tokyo Medical and Dental University, Tokyo, Japan
| | - Juan Alejandro Oliva Trejo
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Fumiko Kodama
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Miyuki Takagi
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Nobuhiro Tada
- Atopy Research Center, Juntendo University School of Medicine, Tokyo, Japan
| | - Takashi Ueno
- Laboratory of Proteomics and Medical Science, Research Support Center, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Ryuichi Nishinakamura
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Yasuhiko Tomino
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Katsuhiko Asanuma
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Abstract
Hypertensive kidney disease classically entails nephroangiosclerosis and hyalinosis with glomerular damage. However, in recent years, several evidences showed that high blood pressure also injures tubular cells, inducing epithelial-to-mesenchymal transition and tubulointerstitial fibrosis. Recently investigated mechanisms are also podocyte effacement and loss, which lead to denudation of the glomerular basement membrane and focal adhesion of the tufts to the Bowman's capsule, with reduced filtration and scars. Starting from the classic concept of nephroangiosclerosis, this review examines the recently emerged knowledge of new biochemical and molecular mechanisms underlying the kidney damage in hypertension and discusses how viable podocytes or podocyte-deriving proteins are promising tools for early diagnosis of renal remodelling in hypertension.
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22
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Exosomes from high glucose-treated glomerular endothelial cells trigger the epithelial-mesenchymal transition and dysfunction of podocytes. Sci Rep 2017; 7:9371. [PMID: 28839221 PMCID: PMC5571220 DOI: 10.1038/s41598-017-09907-6] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/31/2017] [Indexed: 01/08/2023] Open
Abstract
New data indicate that abnormal glomerular endothelial cell (GEC)-podocyte crosstalk plays a critical role in diabetic nephropathy (DN). The aim of our study is to investigate the role of exosomes from high glucose (HG)-treated GECs in the epithelial-mesenchymal transition (EMT) and dysfunction of podocytes. In this study, exosomes were extracted from GEC culture supernatants and podocytes were incubated with the GEC-derived exosomes. Here, we demonstrate that HG induces the endothelial-mesenchymal transition (EndoMT) of GECs and HG-treated cells undergoing the EndoMT secrete more exosomes than normal glucose (NG)-treated GECs. We show that GEC-derived exosomes can be internalized by podocytes and exosomes from HG-treated cells undergoing an EndoMT-like process can trigger the podocyte EMT and barrier dysfunction. Our study reveals that TGF-β1 mRNA is enriched in exosomes from HG-treated GECs and probably mediates the EMT and dysfunction of podocytes. In addition, our experimental results illustrate that canonical Wnt/β-catenin signaling is involved in the exosome-induced podocyte EMT. Our findings suggest the importance of paracrine communication via exosomes between cells undergoing the EndoMT and podocytes for renal fibrosis in DN. Thus, protecting GECs from the EndoMT and inhibiting TGF-β1-containing exosomes release from GECs is necessary to manage renal fibrosis in DN.
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23
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Abstract
The role of complement (C) in the pathogenesis or progression of focal segmental glomerulosclerosis (FSGS) is uncertain. The present study assessed the relationship between serum C3, the baseline characteristics, and the progression of FSGS in the cohort and identified the clinical implications of serum C3 levels in patients with FSGS. Compared to the patients with C3 ≥ 85 mg/dL (N = 474), those with C3 < 85 mg/dL (N = 117) presented a higher level of serum creatinine, lower levels of eGFR, hemoglobin, proteinuria, triglyceride, cholesterol, IgA, as well as, severe tubulointerstitial injury (TI). Of the 221 patients with a mean follow-up of 53.3 months, the risk of reaching end-stage renal disease (ESRD) was significantly higher in patients with low serum C3 level (p < 0.001). An additional 40 patients with primary FSGS revealed a significant correlation between MAC and AP (p = 0.003), MAC and serum C3 (p = 0.018), and AP and serum C3 (p = 0.028). Compared to patients with none-to-mild TI, those with moderate-to-severe TI exhibited a lower level of serum C3 and AP, and a higher level of serum MAC. In conclusion, complement activation occurring in patients with FSGS is associated with clinical and histological severities. Low serum C3 was an independent risk factor for poor renal outcome in patients with FSGS.
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Reiser J, Lee HW, Gupta V, Altintas MM. A High-Content Screening Technology for Quantitatively Studying Podocyte Dynamics. Adv Chronic Kidney Dis 2017; 24:183-188. [PMID: 28501082 DOI: 10.1053/j.ackd.2017.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Podocytes form the visceral layer of a kidney glomerulus and express a characteristic octopus-like cellular architecture specialized for the ultrafiltration of blood. The cytoskeletal dynamics and structural elasticity of podocytes rely on the self-organization of highly interconnected actin bundles, and the maintenance of these features is important for the intact glomerular filtration. Development of more differentiated podocytes in culture has dramatically increased our understanding of the molecular mechanisms regulating podocyte actin dynamics. Podocytes are damaged in a variety of kidney diseases, and therapies targeting podocytes are being investigated with increasing efforts. Association between podocyte damage and disease severity-or between podocyte recovery and the performance of therapeutic molecules-have been the venues of research for years. In this perspective, more standardized high--content screening has emerged as a powerful tool for visualization and analysis of podocyte morphology. This high-throughput fluorescence microscopy technique is based on an automated image analysis with simultaneous detection of various phenotypes (multiplexing) across multiple phenotypic parameters (multiparametric). Here, we review the principles of high-content screening technology and summarize efforts to carry out small compound screen using podocytes.
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25
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Abstract
PURPOSE OF REVIEW In this review, we take a combined membrane biologist's and geneticist's view of the podocyte, to examine how genetics have informed our understanding of membrane receptors, channels, and other signaling molecules affecting podocyte health and disease. RECENT FINDINGS An integral part of the kidney, the glomerulus, is responsible for the kidney's filter function. Within the glomerulus, the podocyte is a unique cell serving a critically important role: it is exposed to signals from the urinary space in Bowman's capsule, it receives and transmits signals to/from the basement membrane upon which it elaborates, and it receives signals from the vascular space with which it also communicates, thus exposed to toxins, viruses, chemicals, proteins, and cellular components or debris that flow in the blood stream. Our understanding of how podocytes perform their important role has been largely informed by human genetics, and the recent revolution afforded by exome sequencing has brought a tremendous wealth of new genetic data to light. SUMMARY Genetically defined, rare/orphan podocytopathies, as reviewed here, are critically important to study as they may reveal the next generation targets for precision medicine in nephrology.
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Hu M, Fan M, Zhen J, Lin J, Wang Q, Lv Z, Wang R. FAK contributes to proteinuria in hypercholesterolaemic rats and modulates podocyte F-actin re-organization via activating p38 in response to ox-LDL. J Cell Mol Med 2016; 21:552-567. [PMID: 27704688 PMCID: PMC5323874 DOI: 10.1111/jcmm.13001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 08/29/2016] [Indexed: 11/28/2022] Open
Abstract
Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase that regulates cell adhesion, proliferation and differentiation. In the present study, a rat model of high fat diet-induced hypercholesterolaemia was established to investigate the involvement of FAK in lipid disorder-related kidney diseases. We showed focal fusion of podocyte foot process that occurred at as early as 4 weeks in rats consuming high fat diet, preceding the onset of proteinuria when aberrant phosphorylation of FAK was found. These abnormalities were ameliorated by dietary intervention of TAE226, a reported inhibitor of FAK. FAK is also an adaptor protein initiating cascades of intracellular signals including c-Src, Rho GTPase and mitogen-activated protein kinase (MAPK). P38 MAPK belongs to the latter and is centrally involved in kidney diseases. Our cell culture data revealed oxidized low-density lipoprotein (ox-LDL) triggered hyper-phosphorylation of FAK and p38, ectopic expression of cellular markers (manifested as decreased WT1, podocin and NEPH1, and increased vimentin and mmp9), and re-arrangement of F-actin filaments with enhanced cell motility; these mutations were significantly rectified by FAK shRNA. Notably, pre-treatment of p38 inhibitor did not alter FAK activation, albeit its deletion of p38 hyper-activity and attenuation of cellular abnormalities, demonstrating that p38 acted as a downstream effector of FAK signalling and ox-LDL damaged podocytes in a FAK/p38-dependent manner. This was further identified by animal data that p38 activation was also abrogated by TAE226 treatment in hypercholesterolaemic rats, suggesting that FAK/p38 axis might also be involved in in vivo events. These findings provided a potential early mechanism of hypercholesterolaemia-related podocyte damage and proteinuria.
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Affiliation(s)
- Mengsi Hu
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Minghua Fan
- Department of Obstetrics and Gynecology, The Second Hospital of Shandong University, Jinan, China
| | - Junhui Zhen
- Department of Pathology, School of Medicine, Shandong University, Jinan, China
| | - Jiangong Lin
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Qun Wang
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Zhimei Lv
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Rong Wang
- Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
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Jiang ZZ, Liu YM, Niu X, Yin JY, Hu B, Guo SC, Fan Y, Wang Y, Wang NS. Exosomes secreted by human urine-derived stem cells could prevent kidney complications from type I diabetes in rats. Stem Cell Res Ther 2016; 7:24. [PMID: 26852014 PMCID: PMC4744390 DOI: 10.1186/s13287-016-0287-2] [Citation(s) in RCA: 185] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 01/18/2016] [Accepted: 01/22/2016] [Indexed: 12/16/2022] Open
Abstract
Background Diabetic nephropathy is one of the most serious complications in patients with diabetes. At present, there are no satisfactory treatments available for diabetic nephropathy. Stem cells are currently the main candidates for the development of new treatments for diabetic nephropathy, as they may exert their therapeutic effects mainly through paracrine mechanisms. Exosomes derived from stem cells have been reported to play an important role in kidney injury. In this article, we try to investigate whether exosomes retrieved from urine stem cells could itself prevent diabetic nephropathy at an early stage in vivo and in vitro. Methods Exosomes from conditioned medium of urine-derived stem cells (USCs-Exo) were isolated using ultrafiltration-combined purification methods. USCs-Exo were then verified by morphology, size, and specific biomarkers using transmission electron microscopy, tunable resistive pulse sensing analysis, and western blotting. After establishment of the streptozotocin-induced Sprague–Dawley rat model, the effects of USCs-Exo on kidney injury and angiogenesis were observed via weekly tail intravenous injection of USCs-Exo or control until 12 weeks. In vitro, podocytes cultured in high-glucose medium were treated with USCs-Exo to test the protective effect of USCs-Exo on podocytic apoptosis. Meanwhile, the potential factors in promoting vascular regeneration in USCs-Exo and urine-derived stem cell conditioned medium were investigated by enzyme-linked immunosorbent assay. Results Urine-derived stem cells were cultured and were verified by positive markers for CD29, CD73, CD90 and CD44 antigens, and negative markers for CD34, CD45 and HLA-DR. USCs-Exo were approximately 50–100 nm spherical vesicles, and the specific markers included CD9, CD63 and CD81. Intravenous injections of USCs-Exo could potentially reduce the urine volume and urinary microalbumin excretion, prevent podocyte and tubular epithelial cell apoptosis, suppress the caspase-3 overexpression and increase glomerular endothelial cell proliferation in diabetic rats. In addition, USCs-Exo could reduce podocytic apoptosis induced by high glucose in vitro. USCs-Exo contained the potential factors, including growth factor, transforming growth factor-β1, angiogenin and bone morphogenetic protein-7, which may be related with vascular regeneration and cell survival. Conclusion USCs-Exo may have the potential to prevent kidney injury from diabetes by inhibiting podocyte apoptosis and promoting vascular regeneration and cell survival. Electronic supplementary material The online version of this article (doi:10.1186/s13287-016-0287-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhen-zhen Jiang
- Department of Nephrology and Rheumatology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Yu-mei Liu
- Department of Nephrology and Rheumatology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Xin Niu
- Institute of Microsurgery on Extremities, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Jian-yong Yin
- Department of Nephrology and Rheumatology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Bin Hu
- Institute of Microsurgery on Extremities, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Shang-chun Guo
- Institute of Microsurgery on Extremities, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Ying Fan
- Department of Nephrology and Rheumatology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Yang Wang
- Institute of Microsurgery on Extremities, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
| | - Nian-song Wang
- Department of Nephrology and Rheumatology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, P.R. China.
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28
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Puelles VG, Cullen-McEwen LA, Taylor GE, Li J, Hughson MD, Kerr PG, Hoy WE, Bertram JF. Human podocyte depletion in association with older age and hypertension. Am J Physiol Renal Physiol 2016; 310:F656-F668. [PMID: 26792066 DOI: 10.1152/ajprenal.00497.2015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/12/2016] [Indexed: 12/27/2022] Open
Abstract
Podocyte depletion plays a major role in the development and progression of glomerulosclerosis. Many kidney diseases are more common in older age and often coexist with hypertension. We hypothesized that podocyte depletion develops in association with older age and is exacerbated by hypertension. Kidneys from 19 adult Caucasian American males without overt renal disease were collected at autopsy in Mississippi. Demographic data were obtained from medical and autopsy records. Subjects were categorized by age and hypertension as potential independent and additive contributors to podocyte depletion. Design-based stereology was used to estimate individual glomerular volume and total podocyte number per glomerulus, which allowed the calculation of podocyte density (number per volume). Podocyte depletion was defined as a reduction in podocyte number (absolute depletion) or podocyte density (relative depletion). The cortical location of glomeruli (outer or inner cortex) and presence of parietal podocytes were also recorded. Older age was an independent contributor to both absolute and relative podocyte depletion, featuring glomerular hypertrophy, podocyte loss, and thus reduced podocyte density. Hypertension was an independent contributor to relative podocyte depletion by exacerbating glomerular hypertrophy, mostly in glomeruli from the inner cortex. However, hypertension was not associated with podocyte loss. Absolute and relative podocyte depletion were exacerbated by the combination of older age and hypertension. The proportion of glomeruli with parietal podocytes increased with age but not with hypertension alone. These findings demonstrate that older age and hypertension are independent and additive contributors to podocyte depletion in white American men without kidney disease.
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Affiliation(s)
- Victor G Puelles
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia;
| | - Luise A Cullen-McEwen
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Georgina E Taylor
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Jinhua Li
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Michael D Hughson
- Department of Pathology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Peter G Kerr
- Department of Nephrology, Monash Medical Centre, and Department of Medicine, Monash University, Melbourne, Victoria, Australia; and
| | - Wendy E Hoy
- Centre for Chronic Disease, The University of Queensland, Brisbane, Queensland, Australia
| | - John F Bertram
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
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Kumar PA, Welsh GI, Raghu G, Menon RK, Saleem MA, Reddy GB. Carboxymethyl lysine induces EMT in podocytes through transcription factor ZEB2: Implications for podocyte depletion and proteinuria in diabetes mellitus. Arch Biochem Biophys 2015; 590:10-19. [PMID: 26550927 DOI: 10.1016/j.abb.2015.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/23/2015] [Accepted: 11/02/2015] [Indexed: 01/10/2023]
Abstract
Advanced glycation end-products (AGEs) are implicated in the pathogenesis of diabetic nephropathy (DN). N-carboxymethyl-lysine (CML) is one of the predominant AGEs that accumulate in all renal compartments of diabetic patients. Nevertheless, the direct effect of CML on podocyte biology has not been explored. In this study, we demonstrate the induction of the transcription factor Zeb2 in podocytes upon exposure to CML through activation of NF-kB signaling cascade. Zeb2 orchestrates epithelial-mesenchymal transformation (EMT), during which cell-cell and cell-extracellular matrix interactions are feeble and enable epithelial cells to become invasive. CML treatment induced both NF-kB and Zeb2 promoter activity and suppressed E-cadherin promoter activity. Inhibition of NF-kB activity prevented CML dependent induction of Zeb2 and loss of E-cadherin. While the exposure of podocytes to CML results in increased podocyte permeability, shRNA-mediated knockdown of Zeb2 expression abrogated CML-mediated podocyte permeability. Further, in vivo findings of elevated CML levels concurrent with increased expression of ZEB2 in glomeruli and proteinuria in diabetic rats confirm that CML-mediated manifestations in the kidney under chronic diabetes conditions. These in vitro and in vivo results envisage the novel axis of NFkB-ZEB2 in podocytes playing a significant role in eliciting EMT and pathogenesis of DN.
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Affiliation(s)
- P Anil Kumar
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India; Department of Biochemistry, University of Hyderabad, Hyderabad, India.
| | - Gavin I Welsh
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - G Raghu
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India
| | - Ram K Menon
- Department of Physiology and Pediatric Endocrinology, University of Michigan, Ann Arbor, USA
| | - Moin A Saleem
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, UK
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30
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Yip HK, Yang CC, Chen KH, Huang TH, Chen YL, Zhen YY, Sung PH, Chiang HJ, Sheu JJ, Chang CL, Chen CH, Chang HW, Chen YT. Combined melatonin and exendin-4 therapy preserves renal ultrastructural integrity after ischemia-reperfusion injury in the male rat. J Pineal Res 2015; 59:434-47. [PMID: 26309060 DOI: 10.1111/jpi.12273] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/21/2015] [Indexed: 12/16/2022]
Abstract
We tested whether combined melatonin (Mel) and exendin-4 (Ex4) treatment can better preserve glomerular structural integrity after ischemia-reperfusion (IR) injury compared with either alone. Adult male Sprague Dawley rats (n = 50) were equally divided into sham control (SC), IR, IR-Ex4 (10 μg/kg subcutaneously 30 min after reperfusion and daily for 5 days), IR-Mel (20 mg/kg intraperitoneally at 30 min postreperfusion and 50 mg/kg at 6 and 18 hr), and IR-Ex4-Mel were euthanized at day 14. Serum creatinine level and urine protein-to-creatinine ratio at days 3 and 14 were highest in IR group and lowest in SC, significantly higher in IR-Ex4 and IR-Mel groups than in IR-Ex4-Mel group (all P < 0.001) without significant difference between IR-Ex4 and IR-Mel groups. Changes in podocyte injury score (PIS) and kidney injury score were highest in IR group and lowest in SC, significantly higher in IR-Ex4 and IR-Mel groups than in IR-Ex4-Mel, and significantly higher in IR-Mel group than in IR-Ex4 group (all P < 0.001). Immunohistochemical microscopic findings of the expressions of FSP-1 and WT-1 (two glomerular damage indicators) and KIM-1 and snail (two renal tubular-damaged indicators) showed an identical pattern, whereas the expressions of ZO-1, p-cadherin, podocin, dystroglycan, fibronectin, and synaptopodin (six indices of glomerular integrity) demonstrated an opposite pattern compared to that of PIS among five groups (all P < 0.001). Protein expressions of inflammatory (TNF-α/NF-κB/MMP-9) and oxidative stress (NOX-1, NOX-2, oxidized protein) biomarkers exhibited an identical pattern to that of PIS among five groups (all P < 0.001). Combined melatonin-exednin-4 therapy further protected glomerulus from IR injury.
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Affiliation(s)
- Hon-Kan Yip
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
- Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Chih-Chao Yang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Kuan-Hung Chen
- Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Tien-Hung Huang
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yi-Ling Chen
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yen-Yi Zhen
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Pei-Hsun Sung
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Hsin-Ju Chiang
- Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Jiunn-Jye Sheu
- Division of Thoracic and Cardiovascular Surgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chia-Lo Chang
- Division of Colorectal Surgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chih-Hung Chen
- Divisions of General Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Hsueh-Wen Chang
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Yen-Ta Chen
- Division of Urology, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
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Datta N, Lindfors S, Miura N, Saleem MA, Lehtonen S. Overexpression of transcription factor FOXC2 in cultured human podocytes upregulates injury markers and increases motility. Exp Cell Res 2015; 340:32-42. [PMID: 26524507 DOI: 10.1016/j.yexcr.2015.10.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 10/09/2015] [Accepted: 10/29/2015] [Indexed: 01/23/2023]
Abstract
Obesity and diabetes-related kidney diseases associate with renal failure and cardiovascular morbidity, and represent a major health issue worldwide. However, the molecular mechanisms leading to their development remain poorly understood. We observed increased expression of transcription factor FoxC2 in the podocytes of obese Zucker rats that are insulin resistant and albuminuric. We also found that depletion of adiponectin, an adipocyte-derived hormone whose secretion is decreased in obesity, upregulated FOXC2 in differentiated human podocytes in vitro. Overexpression of FOXC2 in cultured human podocytes led to increased nuclear expression of FOXC2 associated with a change of cellular morphology. This was accompanied by upregulation of vimentin, a key mesenchymal marker, and active beta-catenin, associated with podocyte injury. We also observed re-organization of the actin cytoskeleton, disrupted localization of the tight junction protein ZO-1, and increased motility of podocytes overexpressing FOXC2. These data indicate that the expression of FOXC2 in podocytes needs to be tightly regulated, and that its overexpression induces a chain of cellular events leading to podocyte dysfunction. These changes may lead to podocyte detachment and depletion ultimately contributing to albuminuria. We also suggest a novel molecular mechanism linking obesity-induced decrease in adiponectin to podocyte dysfunction via upregulation of FOXC2.
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Affiliation(s)
- Neeta Datta
- Department of Pathology, University of Helsinki, 00290 Helsinki, Finland
| | - Sonja Lindfors
- Department of Pathology, University of Helsinki, 00290 Helsinki, Finland
| | - Naoyuki Miura
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Moin A Saleem
- Academic and Children's Renal Unit, Dorothy Hodgkin Building, Bristol BS1, United Kingdom
| | - Sanna Lehtonen
- Department of Pathology, University of Helsinki, 00290 Helsinki, Finland.
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32
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Zhang Y, Ma KL, Liu J, Wu Y, Hu ZB, Liu L, Liu BC. Dysregulation of low-density lipoprotein receptor contributes to podocyte injuries in diabetic nephropathy. Am J Physiol Endocrinol Metab 2015; 308:E1140-8. [PMID: 25921580 DOI: 10.1152/ajpendo.00591.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/25/2015] [Indexed: 01/10/2023]
Abstract
Dyslipidemia plays crucial roles in the progression of diabetic nephropathy (DN). This study investigated the effects of high glucose on lipid accumulation in podocytes and explored its underlying mechanisms. Male db/m and db/db mice were fed a normal chow diet for 8 wk. Immortalised mouse podocytes were treated with or without high glucose for 24 h. The changes to the morphology and ultramicrostructures of the kidneys in mice were examined using pathological staining and electron microscopy. Intracellular lipid accumulation was evaluated by Oil Red O staining and a free cholesterol quantitative assay. The expressions of the molecules involved in low-density lipoprotein receptor (LDLr) pathway and podocyte injury were examined using immunofluorescent staining, real-time PCR, and Western blot. There were increased levels of plasma lipid, serum creatinine, and proteinuria in db/db mice compared with db/m mice. Moreover, there was significant mesangial matrix expansion, basement membrane thickening, podocyte foot process effacement, and phenotypic alteration in the db/db group. Additionally, lipid accumulation in the kidneys of db/db mice was increased due to increased protein expressions of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein, and SREBP-2. These effects were further confirmed by in vitro studies. Interestingly, the treatment with LDLr siRNA inhibited lipid accumulation in podocytes and decreased the protein expression of molecules associated with phenotypic alteration in podocytes. High glucose disrupted LDLr feedback regulation in podocytes, which may cause intracellular lipid accumulation and alteration of podocyte phenotype, thereby accelerating DN progression.
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Affiliation(s)
- Yang Zhang
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
| | - Kun Ling Ma
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
| | - Jing Liu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
| | - Yu Wu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
| | - Ze Bo Hu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
| | - Liang Liu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
| | - Bi Cheng Liu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, China
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Puelles VG, Douglas-Denton RN, Cullen-McEwen LA, Li J, Hughson MD, Hoy WE, Kerr PG, Bertram JF. Podocyte Number in Children and Adults: Associations with Glomerular Size and Numbers of Other Glomerular Resident Cells. J Am Soc Nephrol 2015; 26:2277-88. [PMID: 25568174 DOI: 10.1681/asn.2014070641] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 11/02/2014] [Indexed: 11/03/2022] Open
Abstract
Increases in glomerular size occur with normal body growth and in many pathologic conditions. In this study, we determined associations between glomerular size and numbers of glomerular resident cells, with a particular focus on podocytes. Kidneys from 16 male Caucasian-Americans without overt renal disease, including 4 children (≤3 years old) to define baseline values of early life and 12 adults (≥18 years old), were collected at autopsy in Jackson, Mississippi. We used a combination of immunohistochemistry, confocal microscopy, and design-based stereology to estimate individual glomerular volume (IGV) and numbers of podocytes, nonepithelial cells (NECs; tuft cells other than podocytes), and parietal epithelial cells (PECs). Podocyte density was calculated. Data are reported as medians and interquartile ranges (IQRs). Glomeruli from children were small and contained 452 podocytes (IQR=335-502), 389 NECs (IQR=265-498), and 146 PECs (IQR=111-206). Adult glomeruli contained significantly more cells than glomeruli from children, including 558 podocytes (IQR=431-746; P<0.01), 1383 NECs (IQR=998-2042; P<0.001), and 367 PECs (IQR=309-673; P<0.001). However, large adult glomeruli showed markedly lower podocyte density (183 podocytes per 10(6) µm(3)) than small glomeruli from adults and children (932 podocytes per 10(6) µm(3); P<0.001). In conclusion, large adult glomeruli contained more podocytes than small glomeruli from children and adults, raising questions about the origin of these podocytes. The increased number of podocytes in large glomeruli does not match the increase in glomerular size observed in adults, resulting in relative podocyte depletion. This may render hypertrophic glomeruli susceptible to pathology.
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Affiliation(s)
- Victor G Puelles
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | | | - Luise A Cullen-McEwen
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Jinhua Li
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Michael D Hughson
- Department of Pathology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Wendy E Hoy
- Centre for Chronic Disease, The University of Queensland, Brisbane, Australia
| | - Peter G Kerr
- Department of Nephrology, Monash Medical Centre, Melbourne, Australia; and Department of Medicine, Monash University, Melbourne, Australia
| | - John F Bertram
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia;
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Wang Z, Bao H, Ge Y, Zhuang S, Peng A, Gong R. Pharmacological targeting of GSK3β confers protection against podocytopathy and proteinuria by desensitizing mitochondrial permeability transition. Br J Pharmacol 2014; 172:895-909. [PMID: 25262943 DOI: 10.1111/bph.12952] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 08/27/2014] [Accepted: 09/22/2014] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE Mitochondrial dysfunction, triggered by mitochondria permeability transition (MPT), has been centrally implicated in the pathogenesis of podocytopathy and involves a multitude of cell signalling mechanisms, among which, glycogen synthase kinase (GSK) 3β has emerged as the integration point and plays a crucial role. This study aimed to examine the role of GSK3β in podocyte MPT and mitochondrial dysfunction. EXPERIMENTAL APPROACH The regulatory effect of GSK3β on MPT was examined in differentiated podocytes in culture and in a murine model of adriamycin-induced podocytopathy using 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), a highly selective small-molecule inhibitor of GSK3β. KEY RESULTS TDZD-8 therapy prominently ameliorated the proteinuria and glomerular sclerosis in mice with adriamycin nephropathy; this was associated with a correction of GSK3β overactivity in the glomerulus and attenuation of podocyte injuries, including foot process effacement and podocyte death. Consistently, in adriamycin-injured podocytes, TDZD-8 treatment counteracted GSK3β overactivity, improved cell viability and prevented death, concomitant with diminished oxidative stress, improved mitochondrial dysfunction and desensitized MPT. Mechanistically, a discrete pool of GSK3β was found in podocyte mitochondria, which interacted with and phosphorylated clyclophilin F, a key structural component of the MPT pore. TDZD-8 treatment prevented the GSK3β-controlled phosphorylation and activation of cyclophilin F, desensitized MPT and alleviated the damage to mitochondria in podocytes induced by adriamycin in vivo and in vitro. CONCLUSIONS AND IMPLICATIONS Our findings suggest that pharmacological targeting of GSK3β could represent a promising and feasible therapeutic strategy for protecting podocytes against mitochondrial dysfunction induced by oxidative injuries.
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Affiliation(s)
- Zhen Wang
- Department of Nephrology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China; Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Brown University School of Medicine, Providence, RI, USA
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Li D, Wang N, Zhang L, Hanyu Z, Xueyuan B, Fu B, Shaoyuan C, Zhang W, Xuefeng S, Li R, Chen X. Mesenchymal stem cells protect podocytes from apoptosis induced by high glucose via secretion of epithelial growth factor. Stem Cell Res Ther 2014; 4:103. [PMID: 24004644 PMCID: PMC3856604 DOI: 10.1186/scrt314] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 08/02/2013] [Accepted: 08/23/2013] [Indexed: 12/18/2022] Open
Abstract
Introduction The apoptosis and subsequent injury of podocytes plays a pathogenic role in diabetic nephropathy (DN). Mesenchymal stem cells (MSCs) are promising therapeutic cells for preventing apoptosis and reducing cellular injury. Our previous study found that MSCs could protect kidneys from diabetes-induced injury without obvious engraftment. So we evaluated the effects of human adipose-derived MSCs (hAd-MSCs) on podocytic apoptosis and injury induced by high glucose (HG) and the underlying mechanisms. Methods We used flow cytometry, Western blot and confocal fluorescence microscopy to study podocytic apoptosis and injury induced by HG at 24 hours, 48 hours, and 72 hours in the presence or absence of MSC-conditioned medium (CM). An antibody-based cytokine array was used to identify the mediating factor, which was verified by adding the neutralizing antibody (NtAb) to block its function or adding the recombinant cytokine to the medium to induce its function. Results hAd-MSC-CM reduced podocytic apoptosis in a dose-dependent manner, decreased the expression of podocytic cleaved caspase-3, and prevented the reduced expression and maintained the normal arrangement of podocytic synaptopodin and nephrin. However, human embryonic lung cell (Wi38)-CM failed to ameliorate podocytic apoptosis or injury. Twelve cytokines with concentration ratios (MSC-CM/Wi38-CM) >10-fold were identified. Epithelial growth factor (EGF) was singled out for its known ability to prevent apoptosis. Recombinant human EGF (rhEGF) prevented podocytic apoptosis and injury similarly to hAd-MSC-CM but, upon blockade of EGF, the beneficial effect of hAd-MSC-CM decreased dramatically. Conclusions hAd-MSCs prevent podocytic apoptosis and injury induced by HG, mainly through secreting soluble EG.
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Abstract
Nephrotic syndrome (NS) is characterized by heavy proteinuria, hypoalbuminemia, and edema. The underlying causes of NS are diverse and are tied to inheritable and environmental factors. A common diagnostic marker for NS is effacement of podocyte foot processes. The formation and maintenance of foot processes are under the control of many signalling molecules including Rho-GTPases. Our knowledge of Rho-GTPases is based largely on the functions of three prototypic members: RhoA, Rac1, and Cdc42. In the event of podocyte injury, the rearrangement to the actin cytoskeleton is orchestrated largely by this family of proteins. The importance of maintaining proper actin dynamics in podocytes has led to much investigation as to how Rho-GTPases and their regulatory molecules form and maintain foot processes as a critical component of the kidney’s filtration barrier. Modern sequencing techniques have allowed for the identification of novel disease causing mutations in genes such as ARHGDIA, encoding Rho-GDIα. Continued use of whole exome sequencing has the potential to lead to the identification of new mutations in genes encoding Rho-GTPases or their regulatory proteins. Expanding our knowledge of the dynamic regulation of the actin network by Rho-GTPases in podocytes will pave the way for effective therapeutic options for NS patients.
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Arif E, Rathore YS, Kumari B, Ashish F, Wong HN, Holzman LB, Nihalani D. Slit diaphragm protein Neph1 and its signaling: a novel therapeutic target for protection of podocytes against glomerular injury. J Biol Chem 2014; 289:9502-18. [PMID: 24554715 DOI: 10.1074/jbc.m113.505743] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Podocytes are specialized epithelial cells that are critical components of the glomerular filtration barrier, and their dysfunction leads to proteinuria and renal failure. Therefore, preserving podocyte function is therapeutically significant. In this study, we identified Neph1 signaling as a therapeutic target that upon inhibition prevented podocyte damage from a glomerular injury-inducing agent puromycin aminonucleoside (PAN). To specifically inhibit Neph1 signaling, we used a protein transduction approach, where the cytoplasmic domain of Neph1 (Neph1CD) tagged with a protein transduction domain trans-activator of transcription was transduced in cultured podocytes prior to treatment with PAN. The PAN-induced Neph1 phosphorylation was significantly reduced in Neph1CD-transduced cells; in addition, these cells were resistant to PAN-induced cytoskeletal damage. The biochemical analysis using subfractionation studies showed that unlike control cells Neph1 was retained in the lipid raft fractions in the transduced cells following treatment with PAN, indicating that transduction of Neph1CD in podocytes prevented PAN-induced mislocalization of Neph1. In accordance, the immunofluorescence analysis further suggested that Neph1CD-transduced cells had increased ability to retain endogenous Neph1 at the membrane in response to PAN-induced injury. Similar results were obtained when angiotensin was used as an injury-inducing agent. Consistent with these observations, maintaining high levels of Neph1 at the membrane using a podocyte cell line overexpressing chimeric Neph1 increased the ability of podocytes to resist PAN-induced injury and PAN-induced albumin leakage. Using a zebrafish in vivo PAN and adriamycin injury models, we further demonstrated the ability of transduced Neph1CD to preserve glomerular function. Collectively, these results support the conclusion that inhibiting Neph1 signaling is therapeutically significant in preventing podocyte damage from glomerular injury.
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Affiliation(s)
- Ehtesham Arif
- From the Renal Electrolyte and Hypertension Division, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
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Anil Kumar P, Welsh GI, Saleem MA, Menon RK. Molecular and cellular events mediating glomerular podocyte dysfunction and depletion in diabetes mellitus. Front Endocrinol (Lausanne) 2014; 5:151. [PMID: 25309512 PMCID: PMC4174857 DOI: 10.3389/fendo.2014.00151] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/10/2014] [Indexed: 12/11/2022] Open
Abstract
The essential function of the kidney is to ensure formation of a relatively protein-free ultra-filtrate, urine. The rate of filtration and composition of the primary renal filtrate is determined by the transport of fluid and solutes across the glomerular filtration barrier consisting of endothelial cells, the glomerular basement membrane, and podocyte foot processes. In diabetes mellitus (DM), components of the kidney that enable renal filtration get structurally altered and functionally compromised resulting in proteinuria that often progresses to end-stage renal disease. Histological alterations in DM include early hypertrophy of glomerular and tubular components, subsequent thickening of basement membrane in glomeruli and tubules, progressive accumulation of extracellular matrix proteins in the glomerular mesangium and loss of podocytes, together constituting a clinical condition referred to as diabetic nephropathy (DN). The glomerulus has become the focus of research investigating the mechanism of proteinuria. In particular, the progressive dysfunction and/or loss of podocytes that is contemporaneous with proteinuria in DN have attracted intense scientific attention. The absolute number of podocytes predicts glomerular function and podocyte injury is a hallmark of various glomerular diseases. This review discusses the importance of podocytes in normal renal filtration and details the molecular and cellular events that lead to podocyte dysfunction and decreased podocyte count in DN.
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Affiliation(s)
- P. Anil Kumar
- Department of Biochemistry, University of Hyderabad, Hyderabad, India
| | - Gavin I. Welsh
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Moin A. Saleem
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Ram K. Menon
- Pediatric Endocrinology and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
- *Correspondence: Ram K. Menon, University of Michigan Medical School, D1205 MPB/SPC 5718, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-5718, USA e-mail:
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Zhang L, Li K, Liu X, Li D, Luo C, Fu B, Cui S, Zhu F, Zhao RC, Chen X. Repeated systemic administration of human adipose-derived stem cells attenuates overt diabetic nephropathy in rats. Stem Cells Dev 2013; 22:3074-86. [PMID: 23844841 DOI: 10.1089/scd.2013.0142] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Adipose-derived stem cells (ASCs) can alleviate acute kidney injury and promote kidney cell regeneration and repair. To investigate the role of ASCs in diabetic nephropathy (DN), Sprague-Dawley rats were made diabetic by intraperitoneal injection of streptozotocin (STZ) after uninephrectomy. After 12 weeks, proteinuria was well established. Five times of 5×10(6) human ASCs repeatedly injected through a tail vein at 4 weekly intervals. A reduction in proteinuria was not observed in diabetic rats until 24 weeks. However, urinary protein excretion was significantly suppressed at 28 weeks and persisted up to 32 weeks after STZ treatment. ASC treatment significantly attenuated glomerulus hypertrophy and tubular interstitial injury, and led to the downregulation of WT-1 and synaptopodin expression. CFSE labeled ASCs were injected into DN rats via the tail vein. Within 24 h after injection, the cells were detected in lung, spleen, and peritubular regions, but rarely in pancreas. Human Alu gene expression was detected in lung and spleen up to 4 weeks after ASCs injection. ASC treatment did not improve hyperglycemia or pancreatic damage. In vitro, recombinant human glial cell line-derived neurotrophic factor (GDNF) prevented podocyte injury by high glucose similarly to ASC-conditioned medium. After blocking GDNF in ASC-CM with neutralizing antibody, the therapeutic effect of ASC-CM was significantly decreased. ASCs cocultured with podocytes restored the downregulation of synaptopodin expression, which was weakened by GDNF-RNA interfering. These findings indicate that repeated intravenous ASC can reduce diabetic kidney damage in rats even at the progressive stage, and promote podocyte recovery via GDNF secretion.
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Affiliation(s)
- Li Zhang
- 1 State Key Laboratory of Kidney Disease, Department of Nephrology, Chinese PLA General Hospital and Military Medical Postgraduate College , Beijing, China
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Kimura J, Ichii O, Otsuka S, Sasaki H, Hashimoto Y, Kon Y. Close relations between podocyte injuries and membranous proliferative glomerulonephritis in autoimmune murine models. Am J Nephrol 2013; 38:27-38. [PMID: 23817053 DOI: 10.1159/000353093] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/10/2013] [Indexed: 12/19/2022]
Abstract
BACKGROUND Membranous proliferative glomerulonephritis (MPGN) is a major primary cause of chronic kidney disease (CKD). Podocyte injury is crucial in the pathogenesis of glomerular disease with proteinuria, leading to CKD. To assess podocyte injuries in MPGN, the pathological features of spontaneous murine models were analyzed. METHODS The autoimmune-prone mice strains BXSB/MpJ-Yaa and B6.MRL-(D1Mit202-D1Mit403) were used as the MPGN models, and BXSB/MpJ-Yaa(+) and C57BL/6 were used as the respective controls. In addition to clinical parameters and glomerular histopathology, the protein and mRNA levels of podocyte functional markers were evaluated as indices for podocyte injuries. The relation between MPGN pathology and podocyte injuries was analyzed by statistical correlation. RESULTS Both models developed MPGN with albuminuria and elevated serum anti-double-strand DNA (dsDNA) antibody levels. BXSB/MpJ-Yaa and B6.MRL showed severe proliferative lesions with T and B cell infiltrations and membranous lesions with T cell infiltrations, respectively. Foot process effacement and microvillus-like structure formation were observed ultrastructurally in the podocytes of both MPGN models. Furthermore, both MPGN models showed a decrease in immune-positive areas of nephrin, podocin and synaptopodin in the glomerulus, and in the mRNA expression of Nphs1, Nphs2, Synpo, Actn4, Cd2ap, and Podxl in the isolated glomerulus. Significant negative correlations were detected between serum anti-dsDNA antibody levels and glomerular Nphs1 expression, and between urinary albumin-to-creatinine ratio and glomerular expression of Nphs1, Synpo, Actn4, Cd2ap, or Podxl. CONCLUSION MPGN models clearly developed podocyte injuries characterized by the decreased expression of podocyte functional markers with altered morphology. These data emphasized the importance of regulation of podocyte injuries in MPGN.
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Affiliation(s)
- Junpei Kimura
- Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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Balasubramanian S. Progression of chronic kidney disease: Mechanisms and interventions in retardation. APOLLO MEDICINE 2013. [DOI: 10.1016/j.apme.2013.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Lv Z, Hu M, Zhen J, Lin J, Wang Q, Wang R. Rac1/PAK1 signaling promotes epithelial-mesenchymal transition of podocytes in vitro via triggering β-catenin transcriptional activity under high glucose conditions. Int J Biochem Cell Biol 2012; 45:255-64. [PMID: 23153508 DOI: 10.1016/j.biocel.2012.11.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 10/31/2012] [Accepted: 11/05/2012] [Indexed: 02/07/2023]
Abstract
Ras-related C3 botulinum toxin substrate 1 (Rac1), together with its major downstream effector p21-activated kinase 1 (PAK1), has been identified a central role in cellular events such as cell cytoskeletal remodeling that contributed to cell migration and epithelial-mesenchymal transition (EMT). And there are data implicating that podocytes underwent EMT under pathological conditions. However, little is known about mechanisms of podocytes undergoing EMT. To address this, we assessed the cellular changes of podocytes after high glucose stimulation in vitro, detected the effects of Rac1/PAK1 signaling on podocytes in response to the stimuli, and investigated interactions of Rac1/PAK1 axis with β-catenin and Snail under high glucose conditions. We found that in vitro high glucose treatment led to remarkable down-regulation of nephrin and P-cadherin, as well as significant up-regulation of α-SMA and FSP-1, suggesting that in the presence of high glucose, podocytes underwent EMT, during which Rac1/PAK1 signaling was activated. And these were notably ameliorated by Rac1 gene knockdown. Furthermore, β-catenin and Snail nuclear translocation were triggered by Rac1/PAK1 axis, which were both markedly reversed via Rac1 gene knockdown or pretreatment of IPA-3, a PAK1 inhibitor. These findings elaborated that Rac1/PAK1 signaling contributed to high glucose-induced podocyte EMT via promoting β-catenin and Snail transcriptional activities, which could be a potential mechanism involved in podocytes injury in response to stimuli under diabetic conditions.
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Affiliation(s)
- Zhimei Lv
- Department of Nephrology, Provincial Hospital Affiliated to Shandong University, Jinan, China
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Chang JM, Hwang DY, Chen SC, Kuo MC, Hung CC, Hwang SJ, Tsai JC, Chen HC. B7-1 expression regulates the hypoxia-driven cytoskeleton rearrangement in glomerular podocytes. Am J Physiol Renal Physiol 2012; 304:F127-36. [PMID: 23019228 DOI: 10.1152/ajprenal.00108.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Chronic hypoxia has been recognized as a common mechanism driving the progression of many glomerular diseases. Glomerular cells, although susceptible to hypoxic injuries, are less studied to unravel the hypoxia-related influences. In the present study, we showed that both lipopolysaccharide (LPS) and hypoxia induced B7-1 and hypoxia-inducible factor (HIF)-1α expression in podocytes. B7-1, an essential player in the regulation of podocyte stress fibers, interacted directly with the NH(2)-terminal oxygenation domain of HIF-1α protein and, therefore, might interfere with the HIF-related oxidative events. The suggestion was supported by the changes in the expression of inducible nitric oxide synthase and nitric oxide. The orderly arranged stress fibers in differentiated podocytes were disrupted by either LPS or hypoxic stimulation, and the disruption could be rescued if they were brought back to normal oxygen tension. Cell motility increased with the stimulation by LPS and hypoxia, most probably mediated by the induction of B7-1 and HIF-1α, respectively. We generated a B7-1 knockdown podocyte cell line using the lentiviral small interfering RNA system. The LPS- and hypoxia-induced stress fiber disruption was largely prevented in the B7-1 knockdown podocytes. The increased cell motility by LPS and hypoxia stimulations was also ameliorated in the B7-knockdown podocytes. In summary, we found that both B7-1 and HIF were upregulated by LPS and hypoxic stimulations in podocytes and they interacted with each other. Hypoxia disrupted the abundant stress fibers and increased cell motility. These hypoxia-induced changes were prevented in B7-knockdown podocytes, and they highlighted the importance of B7-1 expression in the hypoxia-related podocyte injuries.
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Affiliation(s)
- Jer-Ming Chang
- Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kango Hospital, Kaohsiung, Taiwan
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Liu S, Shi W, Xiao H, Liang X, Deng C, Ye Z, Mei P, Wang S, Liu X, Shan Z, Liang Y, Zhang B, Wang W, Liu Y, Xu L, Xia Y, Ma J, Li Z. Receptor activator of NF-kappaB and podocytes: towards a function of a novel receptor-ligand pair in the survival response of podocyte injury. PLoS One 2012; 7:e41331. [PMID: 22848465 PMCID: PMC3405116 DOI: 10.1371/journal.pone.0041331] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 06/26/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Glomerulosclerosis correlates with reduction in podocyte number that occurs through mechanisms which include apoptosis. Podocyte injury or podocyte loss in the renal glomerulus has been proposed as the crucial mechanism in the development of glomerulosclerosis. However, the mechanism by which podocytes respond to injury is poorly understood. TNF and TNF receptor superfamilies are important in the pathogenesis of podocyte injury and apoptosis. The ligand of receptor activator of NF-kappaB (RANKL) and receptor activator of NF-kappaB (RANK) are members of the TNF and receptor superfamilies. We investigated whether RANK-RANKL is a receptor-ligand complex for podocytes responding to injury. METHODOLOGY/PRINCIPAL FINDINGS In this study, RANKL and RANK were examined in human podocyte diseases and a rat model of puromycin aminonucleoside nephrosis (PAN). Compared with controls, RANK and RANKL were increased in both human podocyte diseases and the rat PAN model; double immunofluorescence staining revealed that RANK protein expression was mainly attributed to podocytes. Immunoelectron microscopy showed that RANK was localized predominantly at the top of the foot process membrane and the cytoplasm of rat podocyte. In addition, RANK was upregulated in mouse podocytes in vitro after injury induced by puromycin aminonucleoside (PA). Knockdown of RANK expression by small interference RNA (siRNA) exacerbated podocyte apoptosis induced by PA. However, RANKL inhibited significantly the apoptosis of podocytes induced by PA. CONCLUSIONS/SIGNIFICANCE These findings suggest the increase in RANK-RANKL expression is a response to podocyte injury, and RANK-RANKL may be a novel receptor-ligand complex for the survival response during podocyte injury.
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Affiliation(s)
- Shuangxin Liu
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- Southern Medical University, Guangzhou, Guangdong, China
| | - Wei Shi
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Houqin Xiao
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Xinling Liang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Chunyu Deng
- Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhiming Ye
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Ping Mei
- Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Suxia Wang
- Department of Pathology, Peking University First Hospital, Beijing, China
| | - Xiaoying Liu
- Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhixin Shan
- Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yongzheng Liang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Bin Zhang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Wenjian Wang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yanhui Liu
- Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Lixia Xu
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yunfeng Xia
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jianchao Ma
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhilian Li
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
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Zhang M, Liu M, Xiong M, Gong J, Tan X. Schisandra chinensis fruit extract attenuates albuminuria and protects podocyte integrity in a mouse model of streptozotocin-induced diabetic nephropathy. JOURNAL OF ETHNOPHARMACOLOGY 2012; 141:111-118. [PMID: 22353431 DOI: 10.1016/j.jep.2012.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 02/03/2012] [Accepted: 02/06/2012] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Schisandra chinensis fruit is widely used in Chinese medicine for the treatment of hepatic, renal, heart, cerebrovascular and infectious diseases. AIM OF THE STUDY To investigate the effects of Schisandra chinensis fruit extract (SE) on albuminuria and podocyte injury as well as the underlying mechanism in the mouse model of streptozotocin (STZ)-induced diabetic nephropathy and in cultured mouse podocyte cells. MATERIALS AND METHODS SE was orally administrated in STZ-induced diabetic nephropathy mice for 7 weeks, at a daily dose of 5g/kg body weight. The urinary albumin/creatinine ratio and urine albumin excretion rate were measured at the 6th and 9th week of the experiment. The extent of glomerulosclerosis and extracellular matrix deposition were determined by periodic acid-silver methenamine and Masson's trichrome staining. The amount of podocytes and the integrity of the slit diaphragm were detected by immunohistological staining of podocyte markers, Wilms' tumor 1 and nephrin. Alpha-smooth muscle actin, E-cadherin and plasminogen activator inhibitor-1 were measured by western blot and immunohistological staining to evaluate the level of epithelial-to-mesenchymal transition (EMT). Real-time reverse transcription PCR was used to detect the mRNA level of E-cadherin, alpha-SMA and snail in cultured podocyte cells. RESULTS Treatment with SE significantly decreased the urine albumin excretion rate and urinary albumin/creatinine ratio. In addition, SE attenuated glomerulosclerosis and protected against podocyte loss and integrity of the slit diaphragm. Furthermore, SE effectively prevented the EMT of podocytes caused by diabetic nephropathy. CONCLUSIONS Our studies suggest that SE might be beneficial for diabetic nephropathy. The effects of SE on attenuating albuminuria and glomerulosclerosis are possibly mediated by preserving podocyte integrity through suppressing EMT.
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MESH Headings
- Administration, Oral
- Albuminuria/etiology
- Albuminuria/genetics
- Albuminuria/metabolism
- Albuminuria/pathology
- Albuminuria/prevention & control
- Animals
- Biomarkers/metabolism
- Blotting, Western
- Cells, Cultured
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/metabolism
- Diabetic Nephropathies/etiology
- Diabetic Nephropathies/genetics
- Diabetic Nephropathies/metabolism
- Diabetic Nephropathies/pathology
- Diabetic Nephropathies/prevention & control
- Epithelial-Mesenchymal Transition/drug effects
- Fruit
- Gene Expression Regulation/drug effects
- Immunohistochemistry
- Male
- Mice
- Mice, Inbred C57BL
- Phytotherapy
- Plant Extracts/administration & dosage
- Plant Extracts/isolation & purification
- Plant Extracts/pharmacology
- Plants, Medicinal
- Podocytes/drug effects
- Podocytes/metabolism
- Podocytes/pathology
- Protective Agents/administration & dosage
- Protective Agents/isolation & purification
- Protective Agents/pharmacology
- RNA, Messenger/metabolism
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Schisandra/chemistry
- Time Factors
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Affiliation(s)
- Mianzhi Zhang
- Nephrology Division, Gongan Hospital, 78 Nanjin Road, Tianjin 300040, China
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46
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Herrmann A, Tozzo E, Funk J. Semi-automated quantitative image analysis of podocyte desmin immunoreactivity as a sensitive marker for acute glomerular damage in the rat puromycin aminonucleoside nephrosis (PAN) model. ACTA ACUST UNITED AC 2012; 64:45-9. [DOI: 10.1016/j.etp.2010.06.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 06/02/2010] [Indexed: 10/19/2022]
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47
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Abstract
As an integral member of the filtration barrier in the kidney glomerulus, the podocyte is in a unique geographical position: It is exposed to chemical signals from the urinary space (Bowman's capsule), it receives and transmits chemical and mechanical signals to/from the glomerular basement membrane upon which it elaborates, and it receives chemical and mechanical signals from the vascular space with which it also communicates. As with every cell, the ability of the podocyte to receive signals from the surrounding environment and to translate them to the intracellular milieu is dependent largely on molecules residing on the cell membrane. These molecules are the first-line soldiers in the ongoing battle to sense the environment, to respond to friendly signals, and to defend against injurious foes. In this review, we take a membrane biologist's view of the podocyte, examining the many membrane receptors, channels, and other signaling molecules that have been implicated in podocyte biology. Although we attempt to be comprehensive, our goal is not to capture every membrane-mediated pathway but rather to emphasize that this approach may be fruitful in understanding the podocyte and its unique properties.
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Affiliation(s)
- Anna Greka
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
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48
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Camici M, Carpi A, Cini G, Galetta F, Abraham N. Podocyte dysfunction in aging--related glomerulosclerosis. Front Biosci (Schol Ed) 2011; 3:995-1006. [PMID: 21622249 DOI: 10.2741/204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We review podocyte molecular structure and function, consider the underlying mechanisms related to podocyte dysfunction and propose that podocyte dysfunction be considered in the evaluation and management of age-associated glomerulosclerosis. With aging, progressive sympathetic activation, increased intrarenal renin-angiotensin system (RAS) activity, endothelin system and oxidative stress and reduced nitric oxide (NO)-availability can damage podocytes. Apoptosis and proliferation are the principal podocyte changes following injury with the latter leading to sclerosis and loss of nephrons. Podocyte loss can be evaluated by either determining their average number in biopsed glomeruli or by estimating podocyte number or their associated molecules in urine sediment. Podocyturia may be considered a marker of active glomerular disease. Preliminary data suggest that antiadrenergic drugs, angiotensin converting enzyme (ACE) inhibitors, RAS blocking drugs, endothelin system inhibitors and reduced oxidative stress can protect podocytes. Thus podocytes appear to play an important role in the pathogenesis, evaluation and therapy of age related glomerulosclerosis.
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Affiliation(s)
- Marcello Camici
- Department of Internal Medicine, Pisa University, Pisa, Italy
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Perysinaki GS, Moysiadis DK, Bertsias G, Giannopoulou I, Kyriacou K, Nakopoulou L, Boumpas DT, Daphnis E. Podocyte main slit diaphragm proteins, nephrin and podocin, are affected at early stages of lupus nephritis and correlate with disease histology. Lupus 2011; 20:781-91. [PMID: 21478284 DOI: 10.1177/0961203310397412] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Renal podocytes and their slit diaphragms ensure the integrity of the renal basement membrane that forms the barrier to urinary protein loss. A putative disruption of the slit diaphragm and its main protein components, nephrin and podocin, may be implicated in the pathogenesis of lupus nephritis (LN). We studied the glomerular protein expression of nephrin and podocin in NZB/W LN mice by Western blot and immunofluorescence; mRNA levels were measured by real-time PCR. Human kidney biopsies of class II (n = 5), IV (n = 4), V (n = 7) LN were evaluated for nephrin expression by immunohistochemistry. Glomerular protein expression of nephrin and podocin were significantly reduced in NZB/W LN, starting from the earlier stages (mild mesangial LN) and becoming pronounced at advanced histological forms (focal and diffuse proliferative LN). Nephrin and podocin mRNA levels were substantially decreased in diffuse proliferative disease. Decreased expression of both proteins correlated with electron microscopy findings of distorted slit diaphragms. In patients with LN, nephrin was decreased particularly in diffuse proliferative LN. The main slit diaphragm proteins, nephrin and podocin, are affected from the earlier stages of LN and their expression correlates with disease histology. Our findings suggest a novel role of podocytes and their structures in immune-mediated nephritis.
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Affiliation(s)
- G S Perysinaki
- Laboratory of Nephrology, Medical Department, University of Crete, Greece
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50
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Effects of angiotensin receptor blocker on phenotypic alterations of podocytes in early diabetic nephropathy. Am J Med Sci 2011; 341:207-14. [PMID: 21326079 DOI: 10.1097/maj.0b013e3182010da9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Emerging evidence suggests that podocyte injury is a crucial event in the stage of diabetic nephropathy (DN), a process in which angiotensin II is implicated. In this study, the authors investigated the influence of irbesartan, an angiotensin receptor blocker, on the phenotypic alterations of podocytes in experimental DN. METHODS DN was induced by combination of high-sucrose, high-fat diet and intraperitoneal injection of low dose of streptozotocin (35 mg/kg) in spontaneously hypertensive rats. Diabetic rats were treated with irbesartan (50 mg/kg/d) by gavage for 8 weeks. Nondiabetic normotensive Wistar-Kyoto rats, which have the same genetic background as spontaneously hypertensive rat, were used as controls. The renal histological changes were investigated by light and electron microscopy. The epithelial marker of nephrin and mesenchymal marker of desmin were detected by real-time reverse transcriptase-polymerase chain reaction and Western blotting. RESULTS Compared with controls, diabetic rats were associated with mesangial matrix deposition, thickening of glomerular basement membrane, albuminuria, loss of podocytes and effacement of foot processes. Furthermore, the expression of nephrin was significantly reduced whereas desmin was increased. Irbesartan treatment not only lowered blood pressure and albuminuria but also attenuated podocyte loss, maintenance of nephrin expression and inhibition of desmin expression. CONCLUSIONS This study demonstrates that early irbesartan intervention attenuates the podocyte damage and ameliorates phenotypic alterations of podocytes, which provides a novel insight for the early application of angiotensin receptor blocker to prevent the development of DN.
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