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Xu T, Herkens L, Jia T, Klinkhammer BM, Kant S, Krusche CA, Buhl EM, Hayat S, Floege J, Strnad P, Kramann R, Djudjaj S, Boor P. The role of desmoglein-2 in kidney disease. Kidney Int 2024; 105:1035-1048. [PMID: 38395410 DOI: 10.1016/j.kint.2024.01.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/07/2023] [Accepted: 01/09/2024] [Indexed: 02/25/2024]
Abstract
Desmosomes are multi-protein cell-cell adhesion structures supporting cell stability and mechanical stress resilience of tissues, best described in skin and heart. The kidney is exposed to various mechanical stimuli and stress, yet little is known about kidney desmosomes. In healthy kidneys, we found desmosomal proteins located at the apical-junctional complex in tubular epithelial cells. In four different animal models and patient biopsies with various kidney diseases, desmosomal components were significantly upregulated and partly miss-localized outside of the apical-junctional complexes along the whole lateral tubular epithelial cell membrane. The most upregulated component was desmoglein-2 (Dsg2). Mice with constitutive tubular epithelial cell-specific deletion of Dsg2 developed normally, and other desmosomal components were not altered in these mice. When challenged with different types of tubular epithelial cell injury (unilateral ureteral obstruction, ischemia-reperfusion, and 2,8-dihydroxyadenine crystal nephropathy), we found increased tubular epithelial cell apoptosis, proliferation, tubular atrophy, and inflammation compared to wild-type mice in all models and time points. In vitro, silencing DSG2 via siRNA weakened cell-cell adhesion in HK-2 cells and increased cell death. Thus, our data show a prominent upregulation of desmosomal components in tubular cells across species and diseases and suggest a protective role of Dsg2 against various injurious stimuli.
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Affiliation(s)
- Tong Xu
- Institute of Pathology, RWTH Aachen University, Aachen, Germany; Department of Urology, the First Affiliated Hospital of Airforce Medical University, Xi'an, China
| | - Lea Herkens
- Institute of Pathology, RWTH Aachen University, Aachen, Germany
| | - Ting Jia
- Institute of Pathology, RWTH Aachen University, Aachen, Germany; Department of Nephrology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | | | - Sebastian Kant
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany
| | - Claudia A Krusche
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany
| | - Eva M Buhl
- Electron Microscopy Facility, RWTH Aachen University, Aachen, Germany
| | - Sikander Hayat
- Institute of Experimental Medicine and Systems Biology, RWTH Aachen University, Aachen, Germany
| | - Jürgen Floege
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Pavel Strnad
- Department of Medicine III, Gastroenterology, Metabolic Diseases and Intensive Care, RWTH Aachen University, Aachen, Germany
| | - Rafael Kramann
- Institute of Experimental Medicine and Systems Biology, RWTH Aachen University, Aachen, Germany; Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany; Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Sonja Djudjaj
- Institute of Pathology, RWTH Aachen University, Aachen, Germany
| | - Peter Boor
- Institute of Pathology, RWTH Aachen University, Aachen, Germany; Electron Microscopy Facility, RWTH Aachen University, Aachen, Germany; Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany.
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2
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Liu X, Li X, Liao L. Abnormal urodynamic changes in post-upper urinary tract dysfunction in ureteral obstruction rat models. Front Physiol 2024; 15:1341220. [PMID: 38362490 PMCID: PMC10867635 DOI: 10.3389/fphys.2024.1341220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/15/2024] [Indexed: 02/17/2024] Open
Abstract
Objects: This study investigated changes in upper urinary tract urodynamics (UUTU) after upper urinary tract dysfunction (UUTD). Methods: The UUTD model was induced through unilateral ureteral obstruction. To measure the renal pelvis volume, and resting pressure. Ureteral electromyography (EMG) and in situ ureteral constriction experiments were performed. Ureteral tissue was obtained for HE and masson staining, IF staining and IHC research to explore the distribution of Piezo1, and the expression of Piezo1 was studied using Western blotting. Results: The study showed that the renal pelvis volumes and the renal pelvis resting pressures gradually increased post surgery in the experimental group. The degree of ureteral tissue edema, cell necrosis and fibrosis gradually increased. The maximum contraction force and frequency of ureter in the experimental group post surgery were significantly higher than in the sham group. Western blotting showed that the expression intensity of Piezo1 gradually increased and was significantly higher than in the sham group. Further analysis of each sub-layer of the ureter revealed that Piezo1 was highly expressed in the urothelium layer, followed by the suburothelium layer, and had low expression in the smooth muscle cell layer. Conclusion: The study observed that morphological and electrophysiological changes in the upper urinary tract may be important mechanisms of abnormal UUTU. Increased expression of the Piezo1 may be a new molecular mechanism of abnormal urodynamics after UUTD.
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Affiliation(s)
- Xin Liu
- Shandong University, Jinan, Shandong, China
- Department of Urology, China Rehabilitation Research Center, Beijing Bo'ai Hospital, Beijing, China
- University of Health and Rehabilitation Sciences, Qingdao, Shandong, China
- China Rehabilitation Science Institute, Beijing, China
- Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Xing Li
- Department of Urology, China Rehabilitation Research Center, Beijing Bo'ai Hospital, Beijing, China
- School of Rehabilitation, Capital Medical University, Beijing, China
| | - Limin Liao
- Shandong University, Jinan, Shandong, China
- Department of Urology, China Rehabilitation Research Center, Beijing Bo'ai Hospital, Beijing, China
- University of Health and Rehabilitation Sciences, Qingdao, Shandong, China
- China Rehabilitation Science Institute, Beijing, China
- Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
- School of Rehabilitation, Capital Medical University, Beijing, China
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Di X, Gao X, Peng L, Ai J, Jin X, Qi S, Li H, Wang K, Luo D. Cellular mechanotransduction in health and diseases: from molecular mechanism to therapeutic targets. Signal Transduct Target Ther 2023; 8:282. [PMID: 37518181 PMCID: PMC10387486 DOI: 10.1038/s41392-023-01501-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 08/01/2023] Open
Abstract
Cellular mechanotransduction, a critical regulator of numerous biological processes, is the conversion from mechanical signals to biochemical signals regarding cell activities and metabolism. Typical mechanical cues in organisms include hydrostatic pressure, fluid shear stress, tensile force, extracellular matrix stiffness or tissue elasticity, and extracellular fluid viscosity. Mechanotransduction has been expected to trigger multiple biological processes, such as embryonic development, tissue repair and regeneration. However, prolonged excessive mechanical stimulation can result in pathological processes, such as multi-organ fibrosis, tumorigenesis, and cancer immunotherapy resistance. Although the associations between mechanical cues and normal tissue homeostasis or diseases have been identified, the regulatory mechanisms among different mechanical cues are not yet comprehensively illustrated, and no effective therapies are currently available targeting mechanical cue-related signaling. This review systematically summarizes the characteristics and regulatory mechanisms of typical mechanical cues in normal conditions and diseases with the updated evidence. The key effectors responding to mechanical stimulations are listed, such as Piezo channels, integrins, Yes-associated protein (YAP) /transcriptional coactivator with PDZ-binding motif (TAZ), and transient receptor potential vanilloid 4 (TRPV4). We also reviewed the key signaling pathways, therapeutic targets and cutting-edge clinical applications of diseases related to mechanical cues.
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Affiliation(s)
- Xingpeng Di
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xiaoshuai Gao
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Liao Peng
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Jianzhong Ai
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xi Jin
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Shiqian Qi
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Hong Li
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Kunjie Wang
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China.
| | - Deyi Luo
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China.
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Love HD, Evans RC, Hunter K, Roy S, Fissell WH. Functionalizing Polyacrylamide Hydrogels for Renal Cell Culture Under Fluid Shear Stress. Tissue Eng Part A 2022; 28:845-854. [PMID: 36074946 DOI: 10.1089/ten.tea.2022.0079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A functional renal tubule bioreactor needs to reproduce the reabsorption and barrier functions of the renal tubule. Our prior work has demonstrated that primary human renal tubule cells respond favorably when cultured on substrates with elasticity similar to healthy tissue and when subjected to fluid shear stress. Polyacrylamide (PA) is widely used in industrial processes such as water purification because it is electrically neutral and chemically inert. PA is a versatile tool as the concentration and mechanical properties of the gel are easily adjusted by varying the proportions of monomer and crosslinker. Control of mechanical properties is attractive for preparing cell culture substrates with tunable stiffness, but PA's inert chemical properties require additional steps to prepare PA for cell attachment, such as chemical reactions to bind extracellular matrix proteins. Methods based on protein functionalization for cell attachment work well in the short term but fail to provide sufficient attachment to withstand the mechanical traction of fluid shear stress. In our present work, we tested the effects of subjecting primary renal tubule cells to fluid shear stress on an elastic substrate by developing a simple method of incorporating N-(3-Aminopropyl) methacrylamide (APMA) into polyacrylamide hydrogels. Integration of APMA into the polyacrylamide hydrogel formed a non-degradable elastic substrate promoting excellent long-term cell attachment despite the forces of fluid shear stress.
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Affiliation(s)
- Harold Dean Love
- Vanderbilt University Medical Center, Div of Nephrology, P435 - MRB4, 2215-B Garland Ave, Nashville, Tennessee, United States, 37232;
| | - Rachel Carly Evans
- Vanderbilt University Medical Center, Medicine, 1211 Medical Center Drive, Nashville, Tennessee, United States, 37212;
| | - Kuniko Hunter
- Vanderbilt University, Biomedical Engineering, Nashville, Tennessee, United States;
| | - Shuvo Roy
- University of California at San Francisco, Bioengineering and Therapeutic Sciences, San Francisco, California, United States;
| | - William Henry Fissell
- Vanderbilt University Medical Center, Medicine, 1161 21st Avenue South, S3223 MCN, Nashville, Tennessee, United States, 37232-2102;
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Kumar R, Soni H, Afolabi JM, Kanthakumar P, Mankuzhy PD, Iwhiwhu SA, Adebiyi A. Induction of reactive oxygen species by mechanical stretch drives endothelin production in neonatal pig renal epithelial cells. Redox Biol 2022; 55:102394. [PMID: 35841629 PMCID: PMC9289874 DOI: 10.1016/j.redox.2022.102394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 06/23/2022] [Accepted: 07/01/2022] [Indexed: 11/23/2022] Open
Abstract
Vasoactive endothelin (ET) is generated by ET converting enzyme (ECE)-induced proteolytic processing of pro-molecule big ET to biologically active peptides. H2O2 has been shown to increase the expression of ECE1 via transactivation of its promoter. The present study demonstrates that H2O2 triggered ECE1-dependent ET1-3 production in neonatal pig proximal tubule (PT) epithelial cells. A uniaxial stretch of PT cells decreased catalase, increased NADPH oxidase (NOX)2 and NOX4, and increased H2O2 levels. Stretch also increased cellular ECE1, an effect reversed by EUK-134 (a synthetic superoxide dismutase/catalase mimetic), NOX inhibitor apocynin, and siRNA-mediated knockdown of NOX2 and NOX4. Short-term unilateral ureteral obstruction (UUO), an inducer of renal tubular cell stretch and oxidative stress, increased renal ET1-3 generation and vascular resistance (RVR) in neonatal pigs. Despite removing the obstruction, UUO-induced increase in RVR persisted, resulting in early acute kidney injury (AKI). ET receptor (ETR)-operated Ca2+ entry in renal microvascular smooth muscle (SM) via transient receptor potential channel 3 (TRPC3) channels reduced renal blood flow and increased RVR. Although acute reversible UUO (rUUO) did not change protein expression levels of ETR and TRPC3 in renal microvessels, inhibition of ECE1, ETR, and TRPC3 protected against renal hypoperfusion, RVR increase, and early AKI. These data suggest that mechanical stretch-driven oxyradical generation stimulates ET production in neonatal pig renal epithelial cells. ET activates renal microvascular SM TRPC3, leading to persistent vasoconstriction and reduction in renal blood flow. These mechanisms may underlie rUUO-induced renal insufficiency in infants.
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Affiliation(s)
- Ravi Kumar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Hitesh Soni
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jeremiah M Afolabi
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Praghalathan Kanthakumar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Pratheesh D Mankuzhy
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Samson A Iwhiwhu
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Adebowale Adebiyi
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
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6
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Zhao X, Kong Y, Liang B, Xu J, Lin Y, Zhou N, Li J, Jiang B, Cheng J, Li C, Wang W. Mechanosensitive Piezo1 channels mediate renal fibrosis. JCI Insight 2022; 7:152330. [PMID: 35230979 PMCID: PMC9057604 DOI: 10.1172/jci.insight.152330] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 02/25/2022] [Indexed: 11/17/2022] Open
Abstract
Kidney fibrosis is the final common pathway of progressive kidney diseases, the underlying mechanisms of which is not fully understood. The purpose of the current study is to investigate a role of Piezo1, a mechanosensitive nonselective cation channel, in kidney fibrosis. In human fibrotic kidneys, Piezo1 protein expression was markedly upregulated. The abundance of Piezo1 protein in kidneys of mice with UUO or with folic-acid treatment was significantly increased. Inhibition of Piezo1 with GsMTx4 markedly ameliorated UUO or folic acid-induced kidney fibrosis. Mechanical stretch, compression or stiffness induced Piezo1 activation and pro-fibrotic responses in human HK2 cells and primary cultured mouse proximal tubular cells (mPTCs), which were greatly prevented by inhibition or silence of Piezo1. TGFβ-1 induced increased Piezo1 expression and pro-fibrotic phenotypic alterations in HK2 cells and mPTCs, which was again markedly prevented by inhibition of Piezo1. Activation of Piezo1 by Yoda1, a Piezo1 agonist, caused calcium influx and profibrotic responses in HK2 cells and induced calpain2 activation, followed by talin1 cleavage and upregulation of integrinβ1. Also, Yoda1 promoted the link between ECM and integrinβ1. In conclusion, Piezo1 is involved in the progression of kidney fibrosis and pro-fibrotic alterations in renal proximal tubular cells, likely through activating calcium-calpain2-integrinβ1 pathway.
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Affiliation(s)
- Xiaoduo Zhao
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yonglun Kong
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Baien Liang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jinhai Xu
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yu Lin
- Department of Pathology, Zhujiang Hospital, Guangzhou, China
| | - Nan Zhou
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jing Li
- The First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Bin Jiang
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jianding Cheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Chunling Li
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Weidong Wang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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Gualdani R, Seghers F, Yerna X, Schakman O, Tajeddine N, Achouri Y, Tissir F, Devuyst O, Gailly P. Mechanical activation of TRPV4 channels controls albumin reabsorption by proximal tubule cells. Sci Signal 2020; 13:13/653/eabc6967. [DOI: 10.1126/scisignal.abc6967] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Defects in protein reabsorption by the proximal tubule are toxic for epithelial cells in the nephron and may result in nephropathy. In this study, we showed that the ion channel TRPV4 modulated the endocytosis of albumin and low–molecular weight proteins in the proximal tubule. TRPV4 was found at the basolateral side of proximal tubule cells, and its mechanical activation by cell stretching induced Ca2+ entry into the cytosol, which promoted endocytosis. Trpv4−/− mice presented with mild proximal tubule dysfunction under basal conditions. To challenge endocytic function, the permeability of the glomerular filter was altered by systemic delivery of angiotensin II. The proteinuria induced by this treatment was more severe in Trpv4−/− than in Trpv4+/+ mice. Injecting antibodies against the glomerular basement membrane to induce glomerulonephritis is a more pathophysiologically relevant method of impairing glomerular filter permeability. Albuminuria was more severe in mice that lacked TRPV4 specifically in the proximal tubule than in control mice. These results emphasize the importance of TRPV4 in sensing pressure in the proximal tubule in response to variations in the amount of ultrafiltrate and unveil a mechanism that controls protein reabsorption.
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Affiliation(s)
- Roberta Gualdani
- Université catholique de Louvain, Institute of Neuroscience, Cell Physiology, av. Mounier 53/B1.53.17, B-1200 Brussels, Belgium
| | - François Seghers
- Université catholique de Louvain, Institute of Neuroscience, Cell Physiology, av. Mounier 53/B1.53.17, B-1200 Brussels, Belgium
| | - Xavier Yerna
- Université catholique de Louvain, Institute of Neuroscience, Cell Physiology, av. Mounier 53/B1.53.17, B-1200 Brussels, Belgium
| | - Olivier Schakman
- Université catholique de Louvain, Institute of Neuroscience, Cell Physiology, av. Mounier 53/B1.53.17, B-1200 Brussels, Belgium
| | - Nicolas Tajeddine
- Université catholique de Louvain, Institute of Neuroscience, Cell Physiology, av. Mounier 53/B1.53.17, B-1200 Brussels, Belgium
| | - Younès Achouri
- Université catholique de Louvain, de Duve Institute, Transgenic Core Facility, av. Hippocrate 75/B1.75.09, B-1200 Brussels, Belgium
| | - Fadel Tissir
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, av. Hippocrate 73/B1.73.16, B-1200 Brussels, Belgium
| | - Olivier Devuyst
- University of Zurich, Institute of Physiology, Winterthurerstr. 190, CH-8057 Zurich, Switzerland
| | - Philippe Gailly
- Université catholique de Louvain, Institute of Neuroscience, Cell Physiology, av. Mounier 53/B1.53.17, B-1200 Brussels, Belgium
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Kaeidi A, Taghipour Z, Allahtavakoli M, Fatemi I, Hakimizadeh E, Hassanshahi J. Ameliorating effect of troxerutin in unilateral ureteral obstruction induced renal oxidative stress, inflammation, and apoptosis in male rats. Naunyn Schmiedebergs Arch Pharmacol 2020; 393:879-888. [PMID: 31900517 DOI: 10.1007/s00210-019-01801-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/19/2019] [Indexed: 01/08/2023]
Abstract
Unilateral ureteral obstruction (UUO) induces renal injury and troxerutin attenuates the inflammatory parameters and decreases oxidative stress. Accordingly, this study explored the renoprotective effect of troxerutin in UUO-induced renal oxidative stress, inflammation, and apoptosis in male Wistar rats. Animals were randomly separated into five groups (n = 8): control, UUO, and three UUO groups treated with troxerutin (1, 10, and 100 mg/kg). UUO-induced and vehicle/troxerutin administration was continued for 3 days. Then serum creatinine, mean arterial pressure (MAP), renal perfusion pressure (RPP), renal vascular resistance (RVR), and renal blood flow (RBF) were measured. Superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activities, total antioxidant capacity (TAC), and malondialdehyde (MDA) levels as some oxidative stress parameters were measured in the left kidney. The immunoblotting method was applied to evaluate the cleaved caspase-3 Bax, Bcl-2, and TNF-α proteins level. The hematoxylin and eosin method was used to assess the kidney tissue damage score (KTDS). In 3 days, UUO significantly increased serum creatinine level, KTDS, RVR, MDA, Bax, cleaved caspase-3, and TNF-α protein levels (p < 0.05); and decreased RBF, TAC, SOD, catalase, GPx activity levels and Bcl-2 protein expression level in the left kidney (p < 0.05). Troxerutin (100 mg/kg) significantly attenuates the indicators alteration induced by UUO. Our findings represented that the renoprotective effect of troxerutin may be related to its anti-oxidative stress, anti-inflammation, anti-apoptosis, and RBF improver properties.
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Affiliation(s)
- Ayat Kaeidi
- Physiology-Pharmacology Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Khalije Fars Blvd., Pistachio Co. Street, 77175-835, Rafsanjan, 7719617996, Iran.,Department of Physiology and Pharmacology, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Zahra Taghipour
- Department of Anatomy, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Mohammad Allahtavakoli
- Department of Physiology and Pharmacology, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Iman Fatemi
- Research Center of Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran
| | - Elham Hakimizadeh
- Physiology-Pharmacology Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Khalije Fars Blvd., Pistachio Co. Street, 77175-835, Rafsanjan, 7719617996, Iran
| | - Jalal Hassanshahi
- Physiology-Pharmacology Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Khalije Fars Blvd., Pistachio Co. Street, 77175-835, Rafsanjan, 7719617996, Iran. .,Department of Physiology and Pharmacology, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
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9
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Ma H, Lee S, Yang Y, Bedi P, Chou SY. Pentoxifylline protects against loss of function and renal interstitial fibrosis in chronic experimental partial ureteral obstruction. PATHOPHYSIOLOGY 2018; 25:419-425. [DOI: 10.1016/j.pathophys.2018.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/14/2018] [Accepted: 08/22/2018] [Indexed: 12/21/2022] Open
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10
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Assumção R, Pereira-Sampaio M, Sampaio F, de Souza D. Does a Ureteral Obstruction Affect the Contralateral Kidney Morphology? A Stereological Analysis in a Rodent Model. Urol Int 2018; 100:327-332. [DOI: 10.1159/000486760] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/10/2018] [Indexed: 01/05/2023]
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11
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Wei J, Song J, Jiang S, Zhang G, Wheeler D, Zhang J, Wang S, Lai EY, Wang L, Buggs J, Liu R. Role of intratubular pressure during the ischemic phase in acute kidney injury. Am J Physiol Renal Physiol 2016; 312:F1158-F1165. [PMID: 28579560 DOI: 10.1152/ajprenal.00527.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 10/19/2016] [Accepted: 10/31/2016] [Indexed: 01/25/2023] Open
Abstract
Acute kidney injury (AKI) induced by clamping of renal vein or pedicle is more severe than clamping of artery, but the mechanism has not been clarified. In the present study, we tested our hypothesis that increased proximal tubular pressure (Pt) during the ischemic phase exacerbates kidney injury and promotes the development of AKI. We induced AKI by bilateral clamping of renal arteries, pedicles, or veins for 18 min at 37°C, respectively. Pt during the ischemic phase was measured with micropuncture. We found that higher Pt was associated with more severe AKI. To determine the role of Pt during the ischemic phase on the development of AKI, we adjusted the Pt by altering renal artery pressure. We induced AKI by bilateral clamping of renal veins, and the Pt was changed by adjusting the renal artery pressure during the ischemic phase by constriction of aorta and mesenteric artery. When we decreased renal artery pressure from 85 ± 5 to 65 ± 8 mmHg, Pt decreased from 53.3 ± 2.7 to 44.7 ± 2.0 mmHg. Plasma creatinine decreased from 2.48 ± 0.23 to 1.91 ± 0.21 mg/dl at 24 h after renal ischemia. When we raised renal artery pressure to 103 ± 7 mmHg, Pt increased to 67.2 ± 5.1 mmHg. Plasma creatinine elevated to 3.17 ± 0.14 mg·dl·24 h after renal ischemia. Changes in KIM-1, NGAL, and histology were in the similar pattern as plasma creatinine. In summary, we found that higher Pt during the ischemic phase promoted the development of AKI, while lower Pt protected from kidney injury. Pt may be a potential target for treatment of AKI.
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Affiliation(s)
- Jin Wei
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida
| | - Jiangping Song
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida.,State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shan Jiang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida.,Department of Physiology, Zhejiang University School of Medicine, Zhejiang, China
| | - Gensheng Zhang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida.,Department of Physiology, Zhejiang University School of Medicine, Zhejiang, China
| | - Donald Wheeler
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida
| | - Jie Zhang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida
| | - Shaohui Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida
| | - En Yin Lai
- Department of Physiology, Zhejiang University School of Medicine, Zhejiang, China
| | - Lei Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida
| | | | - Ruisheng Liu
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida;
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12
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Renal elasticity quantification by acoustic radiation force impulse applied to the evaluation of kidney diseases: a review. J Investig Med 2016; 63:605-12. [PMID: 25738649 DOI: 10.1097/jim.0000000000000186] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
For centuries, clinicians have used palpation to evaluate abdominal organs. After exploring almost all the different methods of interaction between x-rays, ultrasound, and magnetic fields on tissues, recent interest has focused on the evaluation of their mechanical properties.Acoustic radiation force impulse (ARFI) is a recent, established ultrasound-based diagnostic technique that allows physicians to obtain a measure of the elastic properties of an organ. Shear wave velocity, obtained by the ARFI technique, depends on the elasticity of tissues.To date, there are studies on the ARFI technique applied to normal kidneys, chronic kidney diseases, and kidney transplants. Mechanical properties of the kidney, such as stiffness and deformity, depend on various conditions that alter its histology, in particular the amount of fibrosis in the renal parenchyma; urinary pressure and renal blood perfusion may be other important contributing factors. Unfortunately, the ARFI technique applied to native renal pathologies is still limited, and not all studies are comparable because they used different methods. Therefore, the results reported in recent literature encourage further improvement of this method and the drawing up of standardized guidelines of investigation.
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Raghavan V, Weisz OA. Discerning the role of mechanosensors in regulating proximal tubule function. Am J Physiol Renal Physiol 2015; 310:F1-5. [PMID: 26662200 DOI: 10.1152/ajprenal.00373.2015] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
All cells in the body experience external mechanical forces such as shear stress and stretch. These forces are sensed by specialized structures in the cell known as mechanosensors. Cells lining the proximal tubule (PT) of the kidney are continuously exposed to variations in flow rates of the glomerular ultrafiltrate, which manifest as changes in axial shear stress and radial stretch. Studies suggest that these cells respond acutely to variations in flow by modulating their ion transport and endocytic functions to maintain glomerulotubular balance. Conceptually, changes in the axial shear stress in the PT could be sensed by three known structures, namely, the microvilli, the glycocalyx, and primary cilia. The orthogonal component of the force produced by flow exhibits as radial stretch and can cause expansion of the tubule. Forces of stretch are transduced by integrins, by stretch-activated channels, and by cell-cell contacts. This review summarizes our current understanding of flow sensing in PT epithelia, discusses challenges in dissecting the role of individual flow sensors in the mechanosensitive responses, and identifies potential areas of opportunity for new study.
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Affiliation(s)
- Venkatesan Raghavan
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Ora A Weisz
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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14
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Al-Ani A, Al-Jalham K, Ibrahim T, Majzoub A, Al-Rayashi M, Hayati A, Mubarak W, Al-Rayahi J, Khairy AT. Factors determining renal impairment in unilateral ureteral colic secondary to calcular disease: a prospective study. Int Urol Nephrol 2015; 47:1085-90. [PMID: 25924780 DOI: 10.1007/s11255-015-0986-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 04/12/2015] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To evaluate all possible risk factors that can cause impairment of overall renal function in patients with unilateral ureteral calculus and a normal contralateral kidney. METHODS This is a prospective study of 90 patients who presented to our institute complaining of renal colic secondary to unilateral ureteral calculus. All patients were evaluated with a thorough history, physical examination, and laboratory and radiological investigations including renal function testing, urine analysis, non-contrast computed topography, and radionucleotide scan. Patients were divided into two groups according to their calculated creatinine clearance using the Modification of Diet in Renal Disease (MDRD) formula. Group I (favorable group) had a creatinine clearance >60 ml/min, while group II (unfavorable group) had a creatinine clearance <60 ml/min. RESULTS The patients' mean age ± SD was 38.8 ± 11.4 years. Group I included 54 patients (60 %), while group II included 36 patients (40 %). On univariate analysis, factors that were associated with overall renal function impairment were patients' age, urea-to-creatinine ratio (UCR), use of nonsteroidal anti-inflammatory drugs, stone location, and presence of obstruction. However, using binary logistic regression analysis, only patients' age, UCR, and presence of obstruction sustained statistical significance in association with renal function impairment. CONCLUSION The study of factors that help explain the presence of renal impairment in patients with unilateral ureteral calculus is important in the clinical setting. Patients' age, urea-to-creatinine ratio, and degree of obstruction seem to be significantly associated with overall renal function impairment.
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Affiliation(s)
- Ammar Al-Ani
- Department of Urology, Hamad Medical Corporation, Doha, Qatar
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15
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Denker E, Sehring IM, Dong B, Audisso J, Mathiesen B, Jiang D. Regulation by a TGFβ-ROCK-actomyosin axis secures a non-linear lumen expansion that is essential for tubulogenesis. Development 2015; 142:1639-50. [PMID: 25834020 DOI: 10.1242/dev.117150] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 03/04/2015] [Indexed: 02/01/2023]
Abstract
Regulation of lumen growth is crucial to ensure the correct morphology, dimensions and function of a tubular structure. How this is controlled is still poorly understood. During Ciona intestinalis notochord tubulogenesis, single extracellular lumen pockets grow between pairs of cells and eventually fuse into a continuous tube. Here, we show that lumen growth exhibits a lag phase, during which the luminal membranes continue to grow but the expansion of the apical/lateral junction pauses for ∼30 min. Inhibition of non-muscle myosin II activity abolishes this lag phase and accelerates expansion of the junction, resulting in the formation of narrower lumen pockets partially fusing into a tube of reduced size. Disruption of actin dynamics, conversely, causes a reversal of apical/lateral junction expansion, leading to a dramatic conversion of extracellular lumen pockets to intracellular vacuoles and a tubulogenesis arrest. The onset of the lag phase is correlated with a de novo accumulation of actin that forms a contractile ring at the apical/lateral junctions. This actin ring actively restricts the opening of the lumen in the transverse plane, allowing sufficient time for lumen growth via an osmotic process along the longitudinal dimension. The dynamics of lumen formation is controlled by the TGFβ pathway and ROCK activity. Our findings reveal a TGFβ-ROCK-actomyosin contractility axis that coordinates lumen growth, which is powered by the dynamics of luminal osmolarity. The regulatory system may function like a sensor/checkpoint that responds to the change of luminal pressure and fine-tunes actomyosin contractility to effect proper tubulogenesis.
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Affiliation(s)
- Elsa Denker
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen N-5008, Norway
| | - Ivonne M Sehring
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen N-5008, Norway
| | - Bo Dong
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen N-5008, Norway College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China Institute of Evolution and Marine Biodiversity, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Julien Audisso
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen N-5008, Norway
| | - Birthe Mathiesen
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen N-5008, Norway
| | - Di Jiang
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, Bergen N-5008, Norway
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16
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Honoré E, Martins JR, Penton D, Patel A, Demolombe S. The Piezo Mechanosensitive Ion Channels: May the Force Be with You! Rev Physiol Biochem Pharmacol 2015; 169:25-41. [DOI: 10.1007/112_2015_26] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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17
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Lee JS, Lim JY, Kim J. Mechanical stretch induces angiotensinogen expression through PARP1 activation in kidney proximal tubular cells. In Vitro Cell Dev Biol Anim 2014; 51:72-8. [DOI: 10.1007/s11626-014-9809-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/04/2014] [Indexed: 01/21/2023]
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18
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Emerging urinary markers of renal injury in obstructive nephropathy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:303298. [PMID: 25101270 PMCID: PMC4101977 DOI: 10.1155/2014/303298] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 05/16/2014] [Indexed: 02/06/2023]
Abstract
The effects of obstruction on renal function are the consequence of many factors that profoundly alter all components of glomerular function. Besides the acute effects on glomerular filtration rate and tubule function, a chronic obstruction induces tubular and interstitial injury that results from the activation of different pathways. The progression of tubulointerstitial injury leads to chronic renal damage characterized by tubular atrophy, inflammatory cell infiltration, and interstitial fibrosis. Obstructive nephropathy is an evolving disease in which the renal damage continues even after relief of the obstruction. In particular, it has been demonstrated that the time of relief is the most important factor in predicting long-term renal function deterioration. In this setting, the EGF/MCP-1 ratio, urinary NGAL, and urinary KIM-1 are useful early biomarkers of progressive renal damage and could have a potential role in predicting the long-term renal outcome. This minireview summarizes the role of these emerging urinary biomarkers of obstructive nephropathy based on the current understanding of the pathophysiology of renal injury.
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19
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Parameswaran H, Lutchen KR, Suki B. A computational model of the response of adherent cells to stretch and changes in substrate stiffness. J Appl Physiol (1985) 2014; 116:825-34. [PMID: 24408996 DOI: 10.1152/japplphysiol.00962.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cells in the body exist in a dynamic mechanical environment where they are subject to mechanical stretch as well as changes in composition and stiffness of the underlying extracellular matrix (ECM). However, the underlying mechanisms by which cells sense and adapt to their dynamic mechanical environment, in particular to stretch, are not well understood. In this study, we hypothesized that emergent phenomena at the level of the actin network arising from active structural rearrangements driven by nonmuscle myosin II molecular motors play a major role in the cellular response to both stretch and changes in ECM stiffness. To test this hypothesis, we introduce a simple network model of actin-myosin interactions that links active self-organization of the actin network to the stiffness of the network and the traction forces generated by the network. We demonstrate that such a network replicates not only the effect of changes in substrate stiffness on cellular traction and stiffness and the dependence of rate of force development by a cell on the stiffness of its substrate, but also explains the physical response of adherent cells to transient and cyclic stretch. Our results provide strong indication that network phenomena governed by the active reorganization of the actin-myosin structure plays an important role in cellular mechanosensing and response to both changes in ECM stiffness and externally applied mechanical stretch.
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20
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Grabias BM, Konstantopoulos K. The physical basis of renal fibrosis: effects of altered hydrodynamic forces on kidney homeostasis. Am J Physiol Renal Physiol 2013; 306:F473-85. [PMID: 24352503 DOI: 10.1152/ajprenal.00503.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Healthy kidneys are continuously exposed to an array of physical forces as they filter the blood: shear stress along the inner lumen of the tubules, distension of the tubular walls in response to changing fluid pressures, and bending moments along both the cilia and microvilli of individual epithelial cells that comprise the tubules. Dysregulation of kidney homeostasis via underlying medical conditions such as hypertension, diabetes, or glomerulonephritis fundamentally elevates the magnitudes of each principle force in the kidney and leads to fibrotic scarring and eventual loss of organ function. The purpose of this review is to summarize the progress made characterizing the response of kidney cells to pathological levels of mechanical stimuli. In particular, we examine important, mechanically responsive signaling cascades and explore fundamental changes in renal cell homeostasis after cyclic strain or fluid shear stress exposure. Elucidating the effects of these disease-related mechanical imbalances on endogenous signaling events in kidney cells presents a unique opportunity to better understand the fibrotic process.
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Affiliation(s)
- Bryan M Grabias
- Dept. of Chemical and Biomolecular Engineering, The Johns Hopkins Univ., New Engineering Bldg. 114, 3400 N. Charles St., Baltimore, MD 21218.
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21
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Peyronnet R, Martins JR, Duprat F, Demolombe S, Arhatte M, Jodar M, Tauc M, Duranton C, Paulais M, Teulon J, Honoré E, Patel A. Piezo1-dependent stretch-activated channels are inhibited by Polycystin-2 in renal tubular epithelial cells. EMBO Rep 2013; 14:1143-8. [PMID: 24157948 DOI: 10.1038/embor.2013.170] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 10/07/2013] [Accepted: 10/07/2013] [Indexed: 01/07/2023] Open
Abstract
Mechanical forces associated with fluid flow and/or circumferential stretch are sensed by renal epithelial cells and contribute to both adaptive or disease states. Non-selective stretch-activated ion channels (SACs), characterized by a lack of inactivation and a remarkably slow deactivation, are active at the basolateral side of renal proximal convoluted tubules. Knockdown of Piezo1 strongly reduces SAC activity in proximal convoluted tubule epithelial cells. Similarly, overexpression of Polycystin-2 (PC2) or, to a greater extent its pathogenic mutant PC2-740X, impairs native SACs. Moreover, PC2 inhibits exogenous Piezo1 SAC activity. PC2 coimmunoprecipitates with Piezo1 and deletion of its N-terminal domain prevents both this interaction and inhibition of SAC activity. These findings indicate that renal SACs depend on Piezo1, but are critically conditioned by PC2.
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Affiliation(s)
- Rémi Peyronnet
- Institut de Pharmacologie Moléculaire et Cellulaire, LabEx ICST, UMR 7275 CNRS, Université de Nice Sophia Antipolis, Valbonne, France
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22
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Rampanelli E, Rouschop K, Teske GJD, Claessen N, Leemans JC, Florquin S. CD44v3-v10 reduces the profibrotic effects of TGF-β1 and attenuates tubular injury in the early stage of chronic obstructive nephropathy. Am J Physiol Renal Physiol 2013; 305:F1445-54. [PMID: 24026183 DOI: 10.1152/ajprenal.00340.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
CD44 family members are cell surface glycoproteins, which are expressed on tubular epithelial cells (TEC) solely upon kidney injury and are involved in renal fibrosis development. Renal interstitial fibrosis is the final manifestation of chronic kidney diseases and is regulated by a complex network of cytokines, including the profibrotic factor transforming growth factor-β1 (TGF-β1) and the two antifibrotic cytokines bone morphogenic protein-7 (BMP-7) and hepatocyte growth factor (HGF). The present study investigates the potential role of CD44 standard (CD44s) and CD44v3-v10 (CD44v3) isoforms as modulators of the balance between TGF-β1 and HGF/BMP-7. CD44s is the shortest and most common isoform. CD44v3-v10 (CD44v3) has heparan sulfate moieties, which enable the binding to HGF/BMP-7, and hence, might exert renoprotective effects. Using transgenic mice overexpressing either CD44s or CD44v3 specifically on proximal TEC, we found that in vitro the overexpression of CD44v3 on primary TEC renders cells less susceptible to TGF-β1 profibrotic actions and more sensitive to BMP-7 and HGF compared with TEC overexpressing CD44s. One day after unilateral ureteric obstruction, obstructed kidneys from CD44v3 transgenic mice showed less tubular damage and myofibroblasts accumulation, which was associated with decreased TGF-β1 signaling and increased BMP-7 synthesis and signaling compared with kidneys from wild-type and CD44s transgenic mice. These data suggest that CD44v3 plays a renoprotective role in early stage of chronic obstructive nephropathy.
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Affiliation(s)
- Elena Rampanelli
- Dept. of Pathology, Rm. L2-112, Academic Medical Center, P.O. Box 22660, 1100 AZ, Amsterdam, The Netherlands.
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Mesrobian HGO, Kryger JV, Groth TW, Fiscus GE, Mirza SP. Urinary Proteome Analysis in Patients With Stable SFU Grade 4 Ureteropelvic Junction Obstruction Differs From Normal. Urology 2013; 82:745.e1-10. [DOI: 10.1016/j.urology.2013.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/29/2013] [Accepted: 06/04/2013] [Indexed: 10/26/2022]
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Abstract
Unilateral ureteropelvic junction obstruction (UPJO) is the most common prenatally detected disease leading to hydronephrosis. The obstructive anatomic lesion leads to varying degrees of hydronephrosis, ranging from no apparent effect on renal function to atrophy. Furthermore, the natural course of hydronephrosis varies from spontaneous resolution to progressive deterioration and may take upwards of 3 years for a kidney to declare itself. The objectives of this article are to update our knowledge regarding the evaluation and management of UPJO in depth and to discuss the emerging value of urinary proteome analysis to the clinical arena.
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Affiliation(s)
- Hrair-George O Mesrobian
- Division of Pediatric Urology, Department of Urology, Medical College and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA.
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25
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Heo J, Sachs F, Wang J, Hua SZ. Shear-induced volume decrease in MDCK cells. Cell Physiol Biochem 2012; 30:395-406. [PMID: 22759987 DOI: 10.1159/000339033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2012] [Indexed: 12/22/2022] Open
Abstract
Using a microfluidic cell volume sensor we measured the change in the cell volume of Madin-Darby Canine Kidney (MDCK) cells induced by shear stress. An increase in shear stress from 0.2 to 2.0 dyn/cm(2) resulted in a volume decrease to a steady state volume ∼ 20 - 30 % smaller than the initial resting cell volume. Independent experiments based on fluorescence quenching confirmed the volume reduction. This shear-induced cell shrinkage was irreversible on the time scale of the experiment (∼ 30 min). Treatment of 0.1 µM Hg(2+) significantly inhibited the volume decrease, suggesting that the shear-induced cell shrinkage is associated with water efflux through aquaporins. The volume decrease cannot be inhibited by 75 mM TEA, 100 µM DIDS, or 100 µM Gd(3+) suggesting that volume reduction is not directly mediated by K(+) and Cl(-)channels that typically function during regulatory volume decrease (RVD), nor is it through cationic stretch-activated ion channels (SACs). The process also appears to be Ca(2+) independent because it was insensitive to intracellular Ca(2+) level. Since cell volume is determined by the intracellular water content, we postulate that the shear induced reductions in cell volume may arise from increased intracellular hydrostatic pressure as the cell is deformed under flow, which promotes the efflux of water. The increase in internal pressure in a deformable object under the flow is supported by the finite element mechanical model.
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Affiliation(s)
- Jinseok Heo
- Department of Physiology and Biophysics, SUNY-Buffalo, Buffalo, NY 14260, USA
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26
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Peyronnet R, Sharif-Naeini R, Folgering JHA, Arhatte M, Jodar M, El Boustany C, Gallian C, Tauc M, Duranton C, Rubera I, Lesage F, Pei Y, Peters DJM, Somlo S, Sachs F, Patel A, Honoré E, Duprat F. Mechanoprotection by polycystins against apoptosis is mediated through the opening of stretch-activated K(2P) channels. Cell Rep 2012; 1:241-50. [PMID: 22832196 DOI: 10.1016/j.celrep.2012.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 12/27/2011] [Accepted: 01/30/2012] [Indexed: 12/31/2022] Open
Abstract
How renal epithelial cells respond to increased pressure and the link with kidney disease states remain poorly understood. Pkd1 knockout or expression of a PC2 pathogenic mutant, mimicking the autosomal dominant polycystic kidney disease, dramatically enhances mechanical stress-induced tubular apoptotic cell death. We show the presence of a stretch-activated K(+) channel dependent on the TREK-2 K(2P) subunit in proximal convoluted tubule epithelial cells. Our findings further demonstrate that polycystins protect renal epithelial cells against apoptosis in response to mechanical stress, and this function is mediated through the opening of stretch-activated K(2P) channels. Thus, to our knowledge, we establish for the first time, both in vitro and in vivo, a functional relationship between mechanotransduction and mechanoprotection. We propose that this mechanism is at play in other important pathologies associated with apoptosis and in which pressure or flow stimulation is altered, including heart failure or atherosclerosis.
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Affiliation(s)
- Rémi Peyronnet
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR CNRS 7275, Université de Nice Sophia Antipolis, 06560 Valbonne, France
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27
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The kinase Pyk2 is involved in renal fibrosis by means of mechanical stretch-induced growth factor expression in renal tubules. Kidney Int 2011; 81:449-57. [PMID: 22157654 DOI: 10.1038/ki.2011.403] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Unilateral ureteral obstruction is a well-established experimental model of progressive renal fibrosis. We tested whether mechanical stretch and subsequent renal tubular distension might lead to renal fibrosis by first studying renal tubular epithelial cells in culture. We found that mechanical stretch induced reactive oxygen species that in turn activated the cytoplasmic proline-rich tyrosine kinase-2 (Pyk2). This kinase is abundantly expressed in tubular epithelial cells where it is activated by several stimuli. Using mice with deletion of Pyk2 we found that the expression of transforming growth factor-β1 induced by mechanical stretch in renal tubular epithelial cells was significantly reduced. The expression of connective tissue growth factor was also reduced in the Pyk2(-/-) mice. We also found that expression of connective tissue growth factor was independent of transforming growth factor-β1, but dependent on the Rho-associated coiled-coil forming protein kinase pathway. Thus, Pyk2 may be an important initiating factor in renal fibrosis and might be a new therapeutic target for ameliorating renal fibrosis.
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Rahimzadeh J, Meng F, Sachs F, Wang J, Verma D, Hua SZ. Real-time observation of flow-induced cytoskeletal stress in living cells. Am J Physiol Cell Physiol 2011; 301:C646-52. [PMID: 21653900 PMCID: PMC3174563 DOI: 10.1152/ajpcell.00099.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 06/06/2011] [Indexed: 01/23/2023]
Abstract
The mechanical stress due to shear flow has profound effects on cell proliferation, transport, gene expression, and apoptosis. The mechanisms for flow sensing and transduction are unclear, but it is postulated that fluid flow pulls upon the apical surface, and the resulting stress is eventually transmitted through the cytoskeleton to adhesion plaques on the basal surface. Here we report a direct observation of this flow-induced stress in the cytoskeleton in living cells using a parallel plate microfluidic chip with a fluorescence resonance energy transfer (FRET)-based mechanical stress sensor in actinin. The sensing cassette was genetically inserted into the cytoskeletal host protein and transfected into Madin-Darby canine kidney cells. A shear stress of 10 dyn/cm(2) resulted in a rapid increase in the FRET ratio indicating a decrease in stress across actinin with flow. The effect was reversible, and cells were able to respond to repeated stimulation and showed adaptive changes in the cytoskeleton. Flow-induced Ca(2+) elevation did not affect the response, suggesting that flow-induced changes in actinin stress are insensitive to intracellular Ca(2+) level. The reduction in FRET ratio suggests actin filaments are under normal compression in the presence of flow shear stress due to changes in cell shape, and/or actinin is not in series with actin. Treatment with cytochalasin-D that disrupts F-actin reduced prestress and the response to flow. The FRET/flow method is capable of resolving changes of stress in multiple proteins with optical spatial resolution and time resolution >1 Hz. This promises to provide insight into the force distribution and transduction in all cells.
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Affiliation(s)
- Jason Rahimzadeh
- Department of Physiology and Biophysics, State University of New York-Buffalo, USA
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29
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Fujiu K, Manabe I, Nagai R. Renal collecting duct epithelial cells regulate inflammation in tubulointerstitial damage in mice. J Clin Invest 2011; 121:3425-41. [PMID: 21821915 DOI: 10.1172/jci57582] [Citation(s) in RCA: 188] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 06/08/2011] [Indexed: 12/23/2022] Open
Abstract
Renal tubulointerstitial damage is the final common pathway leading from chronic kidney disease to end-stage renal disease. Inflammation is clearly involved in tubulointerstitial injury, but it remains unclear how the inflammatory processes are initiated and regulated. Here, we have shown that in the mouse kidney, the transcription factor Krüppel-like factor-5 (KLF5) is mainly expressed in collecting duct epithelial cells and that Klf5 haploinsufficient mice (Klf5+/- mice) exhibit ameliorated renal injury in the unilateral ureteral obstruction (UUO) model of tubulointerstitial disease. Additionally, Klf5 haploinsufficiency reduced accumulation of CD11b+ F4/80(lo) cells, which expressed proinflammatory cytokines and induced apoptosis among renal epithelial cells, phenotypes indicative of M1-type macrophages. By contrast, it increased accumulation of CD11b+ F4/80(hi) macrophages, which expressed CD206 and CD301 and contributed to fibrosis, in part via TGF-β production--phenotypes indicative of M2-type macrophages. Interestingly, KLF5, in concert with C/EBPα, was found to induce expression of the chemotactic proteins S100A8 and S100A9, which recruited inflammatory monocytes to the kidneys and promoted their activation into M1-type macrophages. Finally, assessing the effects of bone marrow-specific Klf5 haploinsufficiency or collecting duct- or myeloid cell-specific Klf5 deletion confirmed that collecting duct expression of Klf5 is essential for inflammatory responses to UUO. Taken together, our results demonstrate that the renal collecting duct plays a pivotal role in the initiation and progression of tubulointerstitial inflammation.
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Affiliation(s)
- Katsuhito Fujiu
- Department of Cardiovascular Medicine, University of Tokyo Graduate School of Medicine, Bunkyo, Tokyo, Japan
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30
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Klein J, Gonzalez J, Miravete M, Caubet C, Chaaya R, Decramer S, Bandin F, Bascands JL, Buffin-Meyer B, Schanstra JP. Congenital ureteropelvic junction obstruction: human disease and animal models. Int J Exp Pathol 2011; 92:168-92. [PMID: 20681980 PMCID: PMC3101490 DOI: 10.1111/j.1365-2613.2010.00727.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 06/03/2010] [Indexed: 02/06/2023] Open
Abstract
Ureteropelvic junction (UPJ) obstruction is the most frequently observed cause of obstructive nephropathy in children. Neonatal and foetal animal models have been developed that mimic closely what is observed in human disease. The purpose of this review is to discuss how obstructive nephropathy alters kidney histology and function and describe the molecular mechanisms involved in the progression of the lesions, including inflammation, proliferation/apoptosis, renin-angiotensin system activation and fibrosis, based on both human and animal data. Also we propose that during obstructive nephropathy, hydrodynamic modifications are early inducers of the tubular lesions, which are potentially at the origin of the pathology. Finally, an important observation in animal models is that relief of obstruction during kidney development has important effects on renal function later in adult life. A major short-coming is the absence of data on the impact of UPJ obstruction on long-term adult renal function to elucidate whether these animal data are also valid in humans.
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Affiliation(s)
- Julie Klein
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Julien Gonzalez
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Mathieu Miravete
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Cécile Caubet
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Rana Chaaya
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Stéphane Decramer
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
- Department of Pediatric Nephrology, Hôpital des Enfants, Centre de Référence du Sud Ouest des Maladies Rénales RaresToulouse, France
| | - Flavio Bandin
- Department of Pediatric Nephrology, Hôpital des Enfants, Centre de Référence du Sud Ouest des Maladies Rénales RaresToulouse, France
| | - Jean-Loup Bascands
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Bénédicte Buffin-Meyer
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
| | - Joost P Schanstra
- Institut National de la Santé et de la Recherche Médicale (INSERM)Toulouse, France
- Université Toulouse III Paul-Sabatier, Institut de Médecine Moléculaire de RangueilToulouse, France
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Drummond IA. Polycystins, focal adhesions and extracellular matrix interactions. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1322-6. [PMID: 21396443 DOI: 10.1016/j.bbadis.2011.03.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 03/02/2011] [Indexed: 11/29/2022]
Abstract
Polycystic kidney disease is the most common heritable disease in humans. In addition to epithelial cysts in the kidney, liver and pancreas, patients with autosomal dominant polycystic kidney disease (ADPKD) also suffer from abdominal hernia, intracranial aneurysm, gastrointestinal cysts, and cardiac valvular defects, conditions often associated with altered extracellular matrix production or integrity. Despite more than a decade of work on the principal ADPKD genes, PKD1 and PKD2, questions remain about the basis of cystic disease and the role of extracellular matrix in ADPKD pathology. This review explores the links between polycystins, focal adhesions, and extracellular matrix gene expression. These relationships suggest roles for polycystins in cell-matrix mechanosensory signaling that control matrix production and morphogenesis. This article is part of a Special Issue entitled: Polycystic Kidney Disease.
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The zebrafish foxj1a transcription factor regulates cilia function in response to injury and epithelial stretch. Proc Natl Acad Sci U S A 2010; 107:18499-504. [PMID: 20937855 DOI: 10.1073/pnas.1005998107] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cilia are essential for normal organ function and developmental patterning, but their role in injury and regeneration responses is unknown. To probe the role of cilia in injury, we analyzed the function of foxj1, a transcriptional regulator of cilia genes, in response to tissue damage and renal cyst formation. Zebrafish foxj1a, but not foxj1b, was rapidly induced in response to epithelial distension and stretch, kidney cyst formation, acute kidney injury by gentamicin, and crush injury in spinal cord cells. Obstruction-induced up-regulation of foxj1a was not inhibited by cycloheximide, identifying foxj1a as a primary response gene to epithelial injury. Foxj1 was also dramatically up-regulated in murine cystic kidney disease epithelia [jck/jck (nek8) and Ift88Tg737Rpw(-/-)] as well as in response to kidney ischemia-reperfusion injury. Obstruction of the zebrafish pronephric tubule caused a rapid increase in cilia beat rate that correlated tightly with expanded tubule diameter and epithelial stretch. Zebrafish foxj1a was specifically required for cilia motility. Enhanced foxj1a expression in obstructed tubules induced cilia motility target genes efhc1, tektin-1, and dnahc9. foxj1a-deficient embryos failed to up-regulate efhc1, tektin-1, and dnahc9 and could not maintain enhanced cilia beat rates after obstruction, identifying an essential role for foxj1 in modulating cilia function after injury. These studies reveal that activation of a Foxj1 transcriptional network of ciliogenic genes is an evolutionarily conserved response to multiple forms of tissue damage and highlight enhanced cilia function as a previously uncharacterized component of organ homeostasis.
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Fujita H, Hida M, Kanemoto K, Fukuda K, Nagata M, Awazu M. Cyclic stretch induces proliferation and TGF-β1-mediated apoptosis via p38 and ERK in ureteric bud cells. Am J Physiol Renal Physiol 2010; 299:F648-55. [DOI: 10.1152/ajprenal.00402.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported that p38 mitogen-activated protein kinase (p38) and phosphorylated ERK are upregulated in cyst epithelium of human renal dysplasia and obstructive uropathy in fetal lambs (Omori S, Fukuzawa R, Hida M, Awazu M. Kidney Int 61: 899–906, 2002; Omori S, Kitagawa H, Koike J, Fujita H, Hida M, Pringle KC, Awazu M. Kidney Int 73: 1031–1037, 2008). Dysplastic epithelium is characterized by proliferation, apoptosis, and upregulation of Pax2 and transforming growth factor (TGF)-β1. In the present study, we investigated whether cyclic mechanical stretching of ureteric bud cells, a mimic of the hydrodynamic derangement after fetal urinary tract obstruction, reproduces events seen in vivo. Cyclic stretch activated p38 and ERK and upregulated Pax2 expression in a time-dependent manner in ureteric bud cells. Stretch-stimulated Pax2 expression was suppressed by a p38 inhibitor, SB203580, or a MEK inhibitor, PD98059. 5-Deoxyuridine incorporation was increased by stretch at 24 h, which was also abolished by SB203580 or PD98059. On the other hand, apoptosis was not induced at 24 h by stretch but was significantly increased at 48 h. TGF-β1 secretion was increased by stretch at 24 h, which was inhibited by SB203580 or PD98059. Inhibition of p38 or ERK as well as anti-TGF-β antibody abolished the stretch-induced apoptosis. Finally, exogenous TGF-β1 induced apoptosis of ureteric bud cells, which was inhibited by SB203580 and PD98059. In conclusion, cyclic stretch induces Pax2 upregulation, proliferation, and TGF-β1-mediated apoptosis, features characteristic of dysplastic epithelium, via p38 and ERK in ureteric bud cells.
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Affiliation(s)
| | | | - Katsuyoshi Kanemoto
- Department of Molecular Pathology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Keiichi Fukuda
- Regenerative Medicine and Advanced Cardiac Therapeutics, Keio University School of Medicine, Tokyo; and
| | - Michio Nagata
- Department of Molecular Pathology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
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Abstract
Autosomal dominant polycystic kidney disease is a common disorder, affecting approximately one in 1,000 individuals. This disease is characterized by the presence of renal and extrarenal cysts, as well as by cardiovascular abnormalities, including hypertension and intracranial aneurysms. Mutations in the PKD1 gene account for 85% of cases, whereas mutations in PKD2 account for the remaining 15% of cases. Findings from the past 10 years indicate that polycystins, the products of the PKD genes, have a key role in renal and vascular mechanosensory transduction. In the primary cilium of renal, nodal, and endothelial cells, polycystins are proposed to act as flow sensors. In addition, the ratio of polycystin-1 to polycystin-2 regulates pressure sensing in arterial myocytes. In this Review, we summarize the data indicating that polycystins are key molecules in mechanotransduction. Moreover, we discuss the role of nucleotide release and autocrine and/or paracrine purinergic signaling in both fluid flow and pressure responses. Finally, we discuss the possible role of altered mechanosensory transduction in the etiology of polycystic kidney disease.
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Affiliation(s)
- Amanda Patel
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR CNRS 6097, Université de Nice-Sophia Antipolis, 06560 Valbonne, France
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Intratubular hydrodynamic forces influence tubulointerstitial fibrosis in the kidney. Curr Opin Nephrol Hypertens 2010; 19:65-71. [PMID: 19851105 DOI: 10.1097/mnh.0b013e32833327f3] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE OF REVIEW Renal epithelial cells respond to mechanical stimuli with immediate transduction events (e.g. activation of ion channels), intermediate biological responses (e.g. changes in gene expression), and long-term cellular adaptation (e.g. protein expression). Progressive renal disease is characterized by disturbed glomerular hydrodynamics that contributes to glomerulosclerosis, but how intratubular biomechanical forces contribute to tubulointerstital inflammation and fibrosis is poorly understood. RECENT FINDINGS In-vivo and in-vitro models of obstructive uropathy demonstrate that tubular stretch induces robust expression of transforming growth factor beta-1, activation of tubular apoptosis, and induction of nuclear factor-kappaB signaling, which contribute to the inflammatory and fibrotic milieu. Nonobstructive structural kidney diseases associated with nephron loss follow a course characterized by compensatory increases of single nephron glomerular filtration rate and tubular flow rate. Resulting increases in tubular fluid shear stress reduce tissue-plasminogen activator and urokinase enzymatic activity, which diminishes breakdown of extracellular matrix. In models of high dietary Na intake, which increases tubular flow, urinary transforming growth factor beta-1 concentrations and renal mitogen-activated protein kinase activity are increased. SUMMARY In conclusion, intratubular biomechanical forces, stretch, and fluid shear stress generate changes in intracellular signaling and gene expression that contribute to the pathobiology of obstructive and nonobstructive kidney disease.
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Wang J, Heo J, Hua SZ. Spatially resolved shear distribution in microfluidic chip for studying force transduction mechanisms in cells. LAB ON A CHIP 2010; 10:235-9. [PMID: 20066252 PMCID: PMC2814362 DOI: 10.1039/b914874d] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fluid shear stress has profound effects on cell physiology. Here we present a versatile microfluidic method capable of generating variable magnitudes, gradients, and different modes of shear flow, to study sensory and force transduction mechanisms in cells. The chip allows cell culture under spatially resolved shear flow conditions as well as study of cell response to shear flow in real-time. Using this chip, we studied the effects of chronic shear stress on cellular functions of Madin-Darby Canine Kidney (MDCK), renal epithelial cells. We show that shear stress causes reorganization of actin cytoskeleton, which suppresses flow-induced Ca(2+) response.
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Affiliation(s)
- Jianbin Wang
- Department of Mechanical and Aerospace Engineering, SUNY-Buffalo, Buffalo, NY 14260, USA
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López-Novoa JM, Nieto MA. Inflammation and EMT: an alliance towards organ fibrosis and cancer progression. EMBO Mol Med 2009; 1:303-14. [PMID: 20049734 PMCID: PMC3378143 DOI: 10.1002/emmm.200900043] [Citation(s) in RCA: 507] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 08/17/2009] [Accepted: 08/26/2009] [Indexed: 12/13/2022] Open
Abstract
Recent advances in our understanding of the molecular pathways that govern the association of inflammation with organ fibrosis and cancer point to the epithelial to mesenchymal transition (EMT) as the common link in the progression of these devastating diseases. The EMT is a crucial process in the development of different tissues in the embryo and its reactivation in the adult may be regarded as a physiological attempt to control inflammatory responses and to 'heal' damaged tissue. However, in pathological contexts such as in tumours or during the development of organ fibrosis, this healing response adopts a sinister nature, steering these diseases towards metastasis and organ failure. Importantly, the chronic inflammatory microenvironment common to fibrotic and cancer cells emerges as a decisive factor in the induction of the pathological EMT.
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Affiliation(s)
- Jose Miguel López-Novoa
- Departamento de Fisiología y Farmacología, Universidad de Salamanca, Edificio Departamental, Campus Miguel de UnamunoSalamanca, Spain
| | - M Angela Nieto
- Instituto de Neurociencias CSIC-UMHSan Juan de Alicante, Spain
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