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‘t Hart DC, van der Vlag J, Nijenhuis T. A Putative Role for TRPC6 in Immune-Mediated Kidney Injury. Int J Mol Sci 2023; 24:16419. [PMID: 38003608 PMCID: PMC10671681 DOI: 10.3390/ijms242216419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/12/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Excessive activation of the immune system is the cause of a wide variety of renal diseases. However, the pathogenic mechanisms underlying the aberrant activation of the immune system in the kidneys often remain unknown. TRPC6, a member of the Ca2+-permeant family of TRPC channels, is important in glomerular epithelial cells or podocytes for the process of glomerular filtration. In addition, TRPC6 plays a crucial role in the development of kidney injuries by inducing podocyte injury. However, an increasing number of studies suggest that TRPC6 is also responsible for tightly regulating the immune cell functions. It remains elusive whether the role of TRPC6 in the immune system and the pathogenesis of renal inflammation are intertwined. In this review, we present an overview of the current knowledge of how TRPC6 coordinates the immune cell functions and propose the hypothesis that TRPC6 might play a pivotal role in the development of kidney injury via its role in the immune system.
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2
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Zhou L, Wu K, Gao Y, Qiao R, Tang N, Dong D, Li XQ, Nong Q, Luo DQ, Xiao Q, Fan X, Duan Q, Cao W. Piperlonguminine attenuates renal fibrosis by inhibiting TRPC6. J Ethnopharmacol 2023; 313:116561. [PMID: 37121453 DOI: 10.1016/j.jep.2023.116561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 04/16/2023] [Accepted: 04/28/2023] [Indexed: 05/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Liuwei Dihuang (LWDH) is a classic prescription that has been used to the treatment of "Kidney-Yin" deficiency syndrome for more than 1000 years in China. Recent studies have confirmed that LWDH can prevent the progression of renal fibrosis. Numerous studies have demonstrated the critical role that TRPC6 plays in the development of renal fibrosis. Due to the complex composition of LWDH and its remarkable therapeutic effect on renal fibrosis, it is possible to discover new active ingredients targeting TRPC6 for the treatment of renal fibrosis. AIM OF STUDY This study aimed to identify selective TRPC6 inhibitors from LWDH and evaluate their therapeutical effects on renal fibrosis. MATERIALS AND METHODS Computer-aided drug design was used to screen the biologically active ingredients of LWDH, and their affinities to human TRPC6 protein were detected by microcalorimetry. TRPC6, TRPC3, and TRPC7 over-expressed HEK293 cells were constructed, and the selective activities of the compounds on TRPC6 were determined by measuring [Ca2+]i in these cells. To establish an in vitro model of renal fibrosis, human renal proximal tubular epithelial HK-2 cells were stimulated with TGF-β1. The therapeutic effects of LWDH compounds on renal fibrosis were then tested by detecting the related proteins. TRPC6 was knocked-down in HK-2 cells to investigate the effects of LWDH active ingredients on TRPC6. Finally, a unilateral ureteral obstruction model of renal fibrosis was established to test the therapeutic effect. RESULTS From hundreds of LWDH ingredients, 64 active components with oral bioavailability ≥30% and drug-likeness index ≥0.18 were acquired. A total of 10 active components were obtained by molecular docking with TRPC6 protein. Among them, 4 components had an affinity with TRPC6. Piperlonguminine (PLG) had the most potent affinity with TRPC6 and blocking effect on TRPC6-mediated Ca2+ entry. A 100 μM of PLG showed no detectable inhibition on TRPC1, TRPC3, TRPC4, TRPC5, or TRPC7-mediated Ca2+ influx into cells. In vitro results indicated that PLG concentration-dependently inhibited the abnormally high expression of α-smooth muscle actin (α-SMA), collagen I, vimentin, and TRPC6 in TGF-β1-induced HK-2 cells. Consistently, PLG also could not further inhibit TGF-β1-induced expressions of these protein biomarkers in TRPC6 knocked-down HK-2 cells. In vivo, PLG dose-dependently reduced urinary protein, serum creatinine, and blood urea nitrogen levels in renal fibrosis mice and markedly alleviated fibrosis and the expressions of α-SMA, collagen I, vimentin, and TRPC6 in kidney tissues. CONCLUSION Our results showed that PLG had anti-renal fibrosis effects by selectively inhibiting TRPC6. PLG might be a promising therapeutic agent for the treatment of renal fibrosis.
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Affiliation(s)
- Lei Zhou
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Kehan Wu
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Yuxuan Gao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Ruizhi Qiao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Na Tang
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Dianchao Dong
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Xiao-Qiang Li
- Department of Pharmacology and Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, School of Pharmacy, Fourth Military Medical University, Xi'an, 710000, China
| | - Qiuna Nong
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Ding-Qiang Luo
- Shaanxi Institute for Food and Drug Control, Xi'an, 710065, China
| | - Qianhan Xiao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Xin Fan
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China
| | - Qimei Duan
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China.
| | - Wei Cao
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, China; Department of Pharmacology and Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, School of Pharmacy, Fourth Military Medical University, Xi'an, 710000, China.
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Mishra S, Ma J, McKoy D, Sasaki M, Farinelli F, Page RC, Ranek MJ, Zachara N, Kass DA. Transient receptor potential canonical type 6 (TRPC6) O-GlcNAcylation at Threonine-221 plays potent role in channel regulation. iScience 2023; 26:106294. [PMID: 36936781 PMCID: PMC10014292 DOI: 10.1016/j.isci.2023.106294] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 01/16/2023] [Accepted: 02/20/2023] [Indexed: 03/11/2023] Open
Abstract
Transient receptor potential canonical type 6 (TRPC6) is a non-voltage-gated channel that principally conducts calcium. Elevated channel activation contributes to fibrosis, hypertrophy, and proteinuria, often coupled to stimulation of nuclear factor of activated T-cells (NFAT). TRPC6 is post-translationally regulated, but a role for O-linked β-N-acetyl glucosamine (O-GlcNAcylation) as elevated by diabetes, is unknown. Here we show TRPC6 is constitutively O-GlcNAcylated at Ser14, Thr70, and Thr221 in the N-terminus ankryn-4 (AR4) and linker (LH1) domains. Mutagenesis to alanine reveals T221 as a critical controller of resting TRPC6 conductance, and associated NFAT activity and pro-hypertrophic signaling. T→A mutations at sites homologous in closely related TRPC3 and TRPC7 also increases their activity. Molecular modeling predicts interactions between Thr221-O-GlcNAc and Ser199, Glu200, and Glu246, and combined alanine substitutions of the latter similarly elevates resting NFAT activity. Thus, O-GlcNAcylated T221 and interactions with coordinating residues is required for normal TRPC6 channel conductance and NFAT activation.
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Affiliation(s)
- Sumita Mishra
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, USA
| | - Desirae McKoy
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Masayuki Sasaki
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Federica Farinelli
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Richard C. Page
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA
| | - Mark J. Ranek
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Natasha Zachara
- Department of Biological Chemistry, Department of Oncology, Johns Hopkins University, Baltimore, MD, USA
| | - David A. Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA
- Corresponding author
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Hagmann H, Khayyat NH, Matin M, Oezel C, Chen H, Schauss A, Schell C, Benzing T, Dryer S, Brinkkoetter PT. Capsazepine (CPZ) Inhibits TRPC6 Conductance and Is Protective in Adriamycin-Induced Nephropathy and Diabetic Glomerulopathy. Cells 2023; 12:cells12020271. [PMID: 36672207 PMCID: PMC9856956 DOI: 10.3390/cells12020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 12/15/2022] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
Reactive oxygen species (ROS), which excessively arise in diabetes and systemic inflammatory diseases, modify cellular lipids and cellular lipid composition leading to altered biophysical properties of cellular membranes. The impact of lipid peroxidation on transmembrane signaling routes is not yet well studied. The canonical transient receptor potential channel 6 (TRPC6) is implicated in the pathogenesis of several forms of glomerular diseases. TRPC6 is sensitive to membrane stretch and relies on a distinct lipid environment. This study investigates the effect of oxidative alterations to plasma membrane lipids on TRPC6 activity and the function of the glomerular filter. Knockout of the anti-oxidative, lipid modifying enzyme paraoxonase 2 (PON2) leads to altered biophysical properties of glomerular epithelial cells, which are called podocytes. Cortical stiffness, quantified by atomic force microscopy, was largely increased in PON2-deficient cultured podocytes. PON2 deficiency markedly enhanced TRPC6 channel currents and channel recovery. Treatment with the amphiphilic substance capsazepine in micromolar doses reduced cortical stiffness and abrogated TRPC6 conductance. In in vivo studies, capsazepine reduced the glomerular phenotype in the model of adriamycin-induced nephropathy in PON2 knockout mice and wildtype littermates. In diabetic AKITA mice, the progression of albuminuria and diabetic kidney disease was delayed. In summary, we provide evidence that the modification of membrane characteristics affects TRPC6 signaling. These results could spur future research to investigate modification of the direct lipid environment of TRPC6 as a future therapeutic strategy in glomerular disease.
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Affiliation(s)
- Henning Hagmann
- Department II of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
- Correspondence:
| | | | - Mahsa Matin
- Department II of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
| | - Cem Oezel
- Department II of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
| | - He Chen
- Department II of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
| | - Astrid Schauss
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), 50931 Cologne, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, University Medical Center Freiburg, 79106 Freiburg, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), 50931 Cologne, Germany
- Systems Biology of Ageing Cologne (Sybacol), 50931 Cologne, Germany
| | - Stuart Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, TX 77204, USA
| | - Paul T. Brinkkoetter
- Department II of Internal Medicine, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
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Staruschenko A, Ma R, Palygin O, Dryer SE. Ion channels and channelopathies in glomeruli. Physiol Rev 2023; 103:787-854. [PMID: 36007181 PMCID: PMC9662803 DOI: 10.1152/physrev.00013.2022] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 11/22/2022] Open
Abstract
An essential step in renal function entails the formation of an ultrafiltrate that is delivered to the renal tubules for subsequent processing. This process, known as glomerular filtration, is controlled by intrinsic regulatory systems and by paracrine, neuronal, and endocrine signals that converge onto glomerular cells. In addition, the characteristics of glomerular fluid flow, such as the glomerular filtration rate and the glomerular filtration fraction, play an important role in determining blood flow to the rest of the kidney. Consequently, disease processes that initially affect glomeruli are the most likely to lead to end-stage kidney failure. The cells that comprise the glomerular filter, especially podocytes and mesangial cells, express many different types of ion channels that regulate intrinsic aspects of cell function and cellular responses to the local environment, such as changes in glomerular capillary pressure. Dysregulation of glomerular ion channels, such as changes in TRPC6, can lead to devastating glomerular diseases, and a number of channels, including TRPC6, TRPC5, and various ionotropic receptors, are promising targets for drug development. This review discusses glomerular structure and glomerular disease processes. It also describes the types of plasma membrane ion channels that have been identified in glomerular cells, the physiological and pathophysiological contexts in which they operate, and the pathways by which they are regulated and dysregulated. The contributions of these channels to glomerular disease processes, such as focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy, as well as the development of drugs that target these channels are also discussed.
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Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, Texas
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Yu J, Li C, Ma L, Zhai B, Xu A, Shao D. Transient receptor potential canonical 6 knockdown ameliorated diabetic kidney disease by inhibiting nuclear factor of activated T cells 2 expression in glomerular mesangial cells. Ren Fail 2022; 44:1780-1790. [DOI: 10.1080/0886022x.2022.2134796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- Jian Yu
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
| | - Chunchun Li
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
| | - Lisha Ma
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
| | - Bin Zhai
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
| | - Aiping Xu
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
| | - Decui Shao
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
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Dryer SE, Kim EY. The Effects of TRPC6 Knockout in Animal Models of Kidney Disease. Biomolecules 2022; 12:1710. [PMID: 36421724 PMCID: PMC9687984 DOI: 10.3390/biom12111710] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 11/21/2023] Open
Abstract
Diseases that induce a loss of renal function affect a substantial portion of the world's population and can range from a slight decline in the glomerular filtration rate or microalbuminuria to complete kidney failure. Kidney disorders can be acute or chronic, but any significant reduction in renal function is associated with increased all-cause morbidity and mortality, especially when the conditions become chronic. There is an urgent need for new therapeutic approaches to slow or halt the progression of kidney disease. One potential target of considerable interest is the canonical transient receptor potential-6 (TRPC6) channel. TRCP6 is a cationic channel with a significant permeability to Ca2+. It is expressed in several tissues, including in multiple cell types of the kidney in glomeruli, microvasculature, and tubules. Here, we will describe TRPC6 channels and their roles in signal transduction, with an emphasis on renal cells, and the studies implicating TRPC6 channels in the progression of inherited and acquired kidney diseases. We then describe studies using TRPC6 knockout mice and rats subjected to treatments that model human diseases, including nephrotic syndromes, diabetic nephropathy, autoimmune glomerulonephritis, and acute kidney injuries induced by renal ischemia and by obstruction of the urinary tract. TRPC6 knockout has been shown to reduce glomerular manifestations of disease in several of these models and reduces renal fibrosis caused by urinary tract obstruction. TRPC6 knockout has proven to be less effective at reducing diabetic nephropathy in mouse and rat models. We also summarize the implications of these studies for drug development.
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Affiliation(s)
- Stuart E. Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001, USA
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, TX 77204-5001, USA
| | - Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001, USA
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Brown BJ, Boekell KL, Stotter BR, Talbot BE, Schlondorff JS. Gain-of-function, focal segmental glomerulosclerosis Trpc6 mutation minimally affects susceptibility to renal injury in several mouse models. PLoS One 2022; 17:e0272313. [PMID: 35913909 PMCID: PMC9342776 DOI: 10.1371/journal.pone.0272313] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/18/2022] [Indexed: 11/18/2022] Open
Abstract
Mutations in TRPC6 are a cause of autosomal dominant focal segmental glomerulosclerosis in humans. Many of these mutations are known to have a gain-of-function effect on the non-specific cation channel function of TRPC6. In vitro studies have suggested these mutations affect several signaling pathways, but in vivo studies have largely compared wild-type and Trpc6-deficient rodents. We developed mice carrying a gain-of-function Trpc6 mutation encoding an E896K amino acid change, corresponding to a known FSGS mutation in TRPC6. Homozygous mutant Trpc6 animals have no appreciable renal pathology, and do not develop albuminuria until very advanced age. The Trpc6E896K mutation does not impart susceptibility to PAN nephrosis. The animals show a slight delay in recovery from the albumin overload model. In response to chronic angiotensin II infusion, Trpc6E896K/E896K mice have slightly greater albuminuria initially compared to wild-type animals, an effect that is lost at later time points, and a statistically non-significant trend toward more glomerular injury. This phenotype is nearly opposite to that of Trpc6-deficient animals previously described. The Trpc6 mutation does not appreciably impact renal interstitial fibrosis in response to either angiotensin II infusion, or folate-induced kidney injury. TRPC6 protein and TRPC6-agonist induced calcium influx could not be detected in glomeruli. In sum, these findings suggest that a gain-of-function Trpc6 mutation confers only a mild susceptibility to glomerular injury in the mouse.
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Affiliation(s)
- Brittney J. Brown
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kimber L. Boekell
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brian R. Stotter
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Nephrology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brianna E. Talbot
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Johannes S. Schlondorff
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Abstract
BACKGROUND Children with severe Henoch-Schönlein purpura nephritis (HSPN) may progress to end-stage renal disease without appropriate treatment. OBJECTIVE This study aimed to investigate the efficacy and safety of tacrolimus combined with glucocorticoids in the treatment of pediatric HSPN. METHODS A total of 87 HSPN patients with urinary protein ≥ 0.75 g/24 h received standard of care, including angiotensin II receptor blockers/angiotensin-converting enzyme inhibitors and glucocorticoids. Patients were divided into three groups and additionally received tacrolimus (n = 30), cyclophosphamide (n = 31), or mycophenolate mofetil (MMF) (n = 26). We monitored outcome measures, including proteinuria, hematuria, and renal function and analyzed the efficacy and side effects in each group. RESULTS At 2-month follow-up, the overall efficacy was 93.3%, 83.9%, and 61.5% for tacrolimus, cyclophosphamide, and MMF, respectively (P < 0.05). Urinary protein significantly decreased for all groups. Urinary red blood cell counts significantly decreased for patients treated with tacrolimus (P < 0.001) and cyclophosphamide (P < 0.05), whereas no significant decrease was seen for those receiving MMF (P = 0.09). Although urine β2-microglobulin significantly decreased following 2 months of treatment with all medications, efficacy was greater with tacrolimus than with cyclophosphamide and MMF (P < 0.001). Major adverse events were respiratory and urinary infections, with MMF having the highest infection rate. The cyclophosphamide group also experienced additional adverse events, including arrhythmia, hemorrhagic cystitis, leukocytosis, thrombocytopenia, and hyperglycemia. CONCLUSIONS These results indicate that tacrolimus is more effective at reducing proteinuria and hematuria and improving renal function, with relatively milder side effects, in the treatment of pediatric HSPN. CLINICAL TRIAL REGISTRATION NUMBER ChiCTR2200055323, retrospectively registered on January 7, 2022.
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Affiliation(s)
- Dengyan Wu
- Department of Pediatric Nephrology, Lanzhou University Second Hospital, Lanzhou, Gansu, 730030, China
| | - Rui Ma
- Department of Pediatric Nephrology, Lanzhou University Second Hospital, Lanzhou, Gansu, 730030, China
| | - Xingmin Wang
- Nantong Institute of Genetics and Reproductive Medicine, Affiliated Maternity and Child Healthcare Hospital of Nantong University, Nantong, Jiangsu, 226018, China
| | - Yonghong Yang
- Department of Pediatric Nephrology, Lanzhou University Second Hospital, Lanzhou, Gansu, 730030, China. .,Department of Pediatrics, Affiliated Maternity and Child Healthcare Hospital of Nantong University, Nantong, Jiangsu, 226018, China. .,Department of Nephrology, Rheumatology, and Immunology, Nantong Children's Hospital, 399 Century Ave., Nantong, Jiangsu, 226018, China.
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Yao X, Guo H, Sun M, Meng S, Zhu B, Fang J, Huang J, Wang H, Xing L. Klotho Ameliorates Podocyte Injury through Targeting TRPC6 Channel in Diabetic Nephropathy. J Diabetes Res 2022; 2022:1329380. [PMID: 35480629 PMCID: PMC9038427 DOI: 10.1155/2022/1329380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/14/2022] [Indexed: 11/25/2022] Open
Abstract
Podocyte damage is vital for the etiopathogenesis of diabetic nephropathy (DN). Klotho (KL), a multifunctional protein, has been demonstrated to have renoprotective effects; nevertheless, the mechanism for protective effect has not been completely elucidated. Transient receptor potential cation channel subfamily C, member 6 (TRPC6), a potential target of KL, is implicated in glomerular pathophysiology. Here, we sought to determine whether KL could protect against podocyte injury through inhibiting TRPC6 in DN. We found that high glucose (HG) triggered podocyte injury as manifested by actin cytoskeleton damage along with the downregulation of KL and Synaptopodin and the upregulation of TRPC6. KL overexpression reversed HG-induced podocytes injury, whereas cotreatment with TRPC6 activator flufenamic acid (FFA) significantly abrogated the beneficial effects conferred by KL. Moreover, KL knockdown in podocytes resulted in actin cytoskeleton impairment, decreased Synaptopodin expression, and increased TRPC6 expression. In db/db mice, KL overexpression inhibited TRPC6 expression and attenuated diabetes-induced podocyte injury, which was accompanied by decreased albuminuria and ameliorated glomerulosclerosis. Our data provided novel mechanistic insights for KL against DN and highlighted TRPC6 as a new target for KL in podocytes to prevent DN.
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Affiliation(s)
- Xingmei Yao
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Hengjiang Guo
- Department of Anesthesiology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Mengyao Sun
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Sixuan Meng
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Bingbing Zhu
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Ji Fang
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Jiebo Huang
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Hao Wang
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Lina Xing
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
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11
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Kim JH, Hwang KH, Dang BTN, Eom M, Kong ID, Gwack Y, Yu S, Gee HY, Birnbaumer L, Park KS, Cha SK. Insulin-activated store-operated Ca 2+ entry via Orai1 induces podocyte actin remodeling and causes proteinuria. Nat Commun 2021; 12:6537. [PMID: 34764278 PMCID: PMC8586150 DOI: 10.1038/s41467-021-26900-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 10/28/2021] [Indexed: 12/28/2022] Open
Abstract
Podocyte, the gatekeeper of the glomerular filtration barrier, is a primary target for growth factor and Ca2+ signaling whose perturbation leads to proteinuria. However, the effects of insulin action on store-operated Ca2+ entry (SOCE) in podocytes remain unknown. Here, we demonstrated that insulin stimulates SOCE by VAMP2-dependent Orai1 trafficking to the plasma membrane. Insulin-activated SOCE triggers actin remodeling and transepithelial albumin leakage via the Ca2+-calcineurin pathway in podocytes. Transgenic Orai1 overexpression in mice causes podocyte fusion and impaired glomerular filtration barrier. Conversely, podocyte-specific Orai1 deletion prevents insulin-stimulated SOCE, synaptopodin depletion, and proteinuria. Podocyte injury and albuminuria coincide with Orai1 upregulation at the hyperinsulinemic stage in diabetic (db/db) mice, which can be ameliorated by the suppression of Orai1-calcineurin signaling. Our results suggest that tightly balanced insulin action targeting podocyte Orai1 is critical for maintaining filter integrity, which provides novel perspectives on therapeutic strategies for proteinuric diseases, including diabetic nephropathy. Perturbations of Ca2+ signaling in podocytes may deteriorate kidney function and eventually lead to proteinuria. Here the authors show that insulin can affect the function of the calcium regulator Ora1 in podocytes, which is critical for maintaining kidney filter integrity.
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Affiliation(s)
- Ji-Hee Kim
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Kyu-Hee Hwang
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Bao T N Dang
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Minseob Eom
- Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - In Deok Kong
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Yousang Gwack
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Seyoung Yu
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Heon Yung Gee
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA.,Institute of Biomedical Research (BIOMED), School of Medical Sciences, Catholic University of Argentina, C1107AAZ, Buenos Aires, Argentina
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.,Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Seung-Kuy Cha
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea. .,Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea. .,Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
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12
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Wang L, Tang Y, Buckley AF, Spurney RF. Blockade of the natriuretic peptide clearance receptor attenuates proteinuria in a mouse model of focal segmental glomerulosclerosis. Physiol Rep 2021; 9:e15095. [PMID: 34755480 PMCID: PMC8578888 DOI: 10.14814/phy2.15095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 12/31/2022] Open
Abstract
Glomerular podocytes play a key role in proteinuric diseases. Accumulating evidence suggests that cGMP signaling has podocyte protective effects. The major source of cGMP generation in podocytes is natriuretic peptides. The natriuretic peptide clearance receptor (NPRC) binds and degrades natriuretic peptides. As a result, NPRC inhibits natriuretic peptide-induced cGMP generation. To enhance cGMP generation in podocytes, we blocked natriuretic peptide clearance using the specific NPRC ligand ANP(4-23). We then studied the effects of NPRC blockade in both cultured podocytes and in a mouse transgenic (TG) model of focal segmental glomerulosclerosis (FSGS) created in our laboratory. In this model, a single dose of the podocyte toxin puromycin aminonucleoside (PAN) causes robust albuminuria in TG mice, but only mild disease in non-TG animals. We found that natriuretic peptides protected cultured podocytes from PAN-induced apoptosis, and that ANP(4-23) enhanced natriuretic peptide-induced cGMP generation in vivo. PAN-induced heavy proteinuria in vehicle-treated TG mice, and this increase in albuminuria was reduced by treatment with ANP(4-23). Treatment with ANP(4-23) also reduced the number of mice with glomerular injury and enhanced urinary cGMP excretion, but these differences were not statistically significant. Systolic BP was similar in vehicle and ANP(4-23)-treated mice. These data suggest that: 1. Pharmacologic blockade of NPRC may be useful for treating glomerular diseases such as FSGS, and 2. Treatment outcomes might be improved by optimizing NPRC blockade to inhibit natriuretic peptide clearance more effectively.
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Affiliation(s)
- Liming Wang
- Division of NephrologyDepartment of MedicineDuke University and Durham VA Medical CentersDurhamNorth CarolinaUSA
| | - Yuping Tang
- Division of NephrologyDepartment of MedicineDuke University and Durham VA Medical CentersDurhamNorth CarolinaUSA
| | - Anne F. Buckley
- Department of PathologyDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Robert F. Spurney
- Division of NephrologyDepartment of MedicineDuke University and Durham VA Medical CentersDurhamNorth CarolinaUSA
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13
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Liu CJ, Cheng CW, Tsai YS, Huang HS. Crosstalk between Renal and Vascular Calcium Signaling: The Link between Nephrolithiasis and Vascular Calcification. Int J Mol Sci 2021; 22:ijms22073590. [PMID: 33808324 PMCID: PMC8036726 DOI: 10.3390/ijms22073590] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/18/2021] [Accepted: 03/26/2021] [Indexed: 12/11/2022] Open
Abstract
Calcium (Ca2+) is an important mediator of multicellular homeostasis and is involved in several diseases. The interplay among the kidney, bone, intestine, and parathyroid gland in Ca2+ homeostasis is strictly modulated by numerous hormones and signaling pathways. The calcium-sensing receptor (CaSR) is a G protein–coupled receptor, that is expressed in calcitropic tissues such as the parathyroid gland and the kidney, plays a pivotal role in Ca2+ regulation. CaSR is important for renal Ca2+, as a mutation in this receptor leads to hypercalciuria and calcium nephrolithiasis. In addition, CaSR is also widely expressed in the vascular system, including vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) and participates in the process of vascular calcification. Aberrant Ca2+ sensing by the kidney and VSMCs, owing to altered CaSR expression or function, is associated with the formation of nephrolithiasis and vascular calcification. Based on emerging epidemiological evidence, patients with nephrolithiasis have a higher risk of vascular calcification, but the exact mechanism linking the two conditions is unclear. However, a dysregulation in Ca2+ homeostasis and dysfunction in CaSR might be the connection between the two. This review summarizes renal calcium handling and calcium signaling in the vascular system, with a special focus on the link between nephrolithiasis and vascular calcification.
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Affiliation(s)
- Chan-Jung Liu
- Department of Urology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704302, Taiwan; (C.-J.L.); (C.-W.C.)
| | - Chia-Wei Cheng
- Department of Urology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704302, Taiwan; (C.-J.L.); (C.-W.C.)
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704302, Taiwan;
- Center for Clinical Medicine Research, National Cheng Kung University Hospital, Tainan 704302, Taiwan
| | - Ho-Shiang Huang
- Department of Urology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704302, Taiwan; (C.-J.L.); (C.-W.C.)
- Correspondence: ; Tel.: +886-6-2353535 (ext. 5251); Fax: +886-6-2766179
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14
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Uijl E, 't Hart DC, Roksnoer LCW, Groningen MCC, van Veghel R, Garrelds IM, de Vries R, van der Vlag J, Zietse R, Nijenhuis T, Joles JA, Hoorn EJ, Danser AHJ. Angiotensin-neprilysin inhibition confers renoprotection in rats with diabetes and hypertension by limiting podocyte injury. J Hypertens 2020; 38:755-64. [PMID: 31790054 DOI: 10.1097/HJH.0000000000002326] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Combined angiotensin receptor--neprilysin inhibition (ARNI) reduces glomerulosclerosis better than single angiotensin receptor blockade (ARB) in diabetic, hypertensive rats. The renoprotective mechanism remains unknown, but may depend on superior blood pressure control, improved renal hemodynamics, suppressed renal inflammation or prevention of podocyte loss. METHODS To address this, TGR(mREN2)27 rats (a model of angiotensin II-dependent hypertension) were made diabetic for 12 weeks and treated with vehicle (n = 10), valsartan (ARB; n = 7) or sacubitril/valsartan (ARNI; n = 8) for the final 3 weeks. Arterial pressure was measured via radiotelemetry. RESULTS Sacubitril/valsartan lowered mean arterial pressure by -50 ± 4 mmHg and valsartan by -43 ± 4 mmHg (P = 0.3). Both treatments lowered albuminuria, but only sacubitril/valsartan maintained high urinary atrial natriuretic peptide, improved glycemic control and protected podocyte integrity, reflected by increased nephrin expression and suppression of transient receptor potential canonical 6 and regulator of calcineurin 1. This resulted in markedly reduced glomerulosclerosis (P < 0.05 vs. control and valsartan). Despite higher effective renal plasma flow and glomerular filtration rates, sacubitril/valsartan did neither improve filtration fraction nor renal immune cell infiltration. CONCLUSION Sacubitril/valsartan offers drug-class-specific renoprotection in a preclinical model of diabetes and hypertension. Renoprotection is unrelated to antihypertensive efficacy, renal hemodynamics or inflammation, but may be related to protective effects of natriuretic peptides on podocyte integrity.
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15
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Lu J, Chen PP, Zhang JX, Li XQ, Wang GH, Yuan BY, Huang SJ, Liu XQ, Jiang TT, Wang MY, Liu WT, Ruan XZ, Liu BC, Ma KL. GPR43 deficiency protects against podocyte insulin resistance in diabetic nephropathy through the restoration of AMPKα activity. Am J Cancer Res 2021; 11:4728-4742. [PMID: 33754024 PMCID: PMC7978296 DOI: 10.7150/thno.56598] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/15/2021] [Indexed: 02/06/2023] Open
Abstract
Rationale: Albuminuria is an early clinical feature in the progression of diabetic nephropathy (DN). Podocyte insulin resistance is a main cause of podocyte injury, playing crucial roles by contributing to albuminuria in early DN. G protein-coupled receptor 43 (GPR43) is a metabolite sensor modulating the cell signalling pathways to maintain metabolic homeostasis. However, the roles of GPR43 in podocyte insulin resistance and its potential mechanisms in the development of DN are unclear. Methods: The experiments were conducted by using kidney tissues from biopsied DN patients, streptozotocin (STZ) induced diabetic mice with or without global GPR43 gene knockout, diabetic rats treated with broad-spectrum oral antibiotics or fecal microbiota transplantation, and cell culture model of podocytes. Renal pathological injuries were evaluated by periodic acid-schiff staining and transmission electron microscopy. The expression of GPR43 with other podocyte insulin resistance related molecules was checked by immunofluorescent staining, real-time PCR, and Western blotting. Serum acetate level was examined by gas chromatographic analysis. The distribution of gut microbiota was measured by 16S ribosomal DNA sequencing with faeces. Results: Our results demonstrated that GPR43 expression was increased in kidney samples of DN patients, diabetic animal models, and high glucose-stimulated podocytes. Interestingly, deletion of GPR43 alleviated albuminuria and renal injury in diabetic mice. Pharmacological inhibition and knockdown of GPR43 expression in podocytes increased insulin-induced Akt phosphorylation through the restoration of adenosine 5'-monophosphate-activated protein kinase α (AMPKα) activity. This effect was associated with the suppression of AMPKα activity through post-transcriptional phosphorylation via the protein kinase C-phospholipase C (PKC-PLC) pathway. Antibiotic treatment-mediated gut microbiota depletion, and faecal microbiota transplantation from the healthy donor controls substantially improved podocyte insulin sensitivity and attenuated glomerular injury in diabetic rats accompanied by the downregulation of the GPR43 expression and a decrease in the level of serum acetate. Conclusion: These findings suggested that dysbiosis of gut microbiota-modulated GPR43 activation contributed to albuminuria in DN, which could be mediated by podocyte insulin resistance through the inhibition of AMPKα activity.
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16
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Golosova D, Palygin O, Bohovyk R, Klemens CA, Levchenko V, Spires DR, Isaeva E, El-Meanawy A, Staruschenko A. Role of opioid signaling in kidney damage during the development of salt-induced hypertension. Life Sci Alliance 2020; 3:3/12/e202000853. [PMID: 33046522 PMCID: PMC7556751 DOI: 10.26508/lsa.202000853] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 02/06/2023] Open
Abstract
Stimulation of kappa opioid receptors modulates calcium influx via TRPC6 channels in podocytes, which ultimately compromises the integrity of the glomerular filtration barrier and promotes a marked worsening of blood pressure control and renal damage. Opioid use is associated with predictors of poor cardiorenal outcomes. However, little is known about the direct impact of opioids on podocytes and renal function, especially in the context of hypertension and CKD. We hypothesize that stimulation of opioid receptors (ORs) contributes to dysregulation of intracellular calcium ([Ca2+]i) homeostasis in podocytes, thus aggravating the development of renal damage in hypertensive conditions. Herein, freshly isolated glomeruli from Dahl salt-sensitive (SS) rats and human kidneys, as well as immortalized human podocytes, were used to elucidate the contribution of specific ORs to calcium influx. Stimulation of κ-ORs, but not μ-ORs or δ-ORs, evoked a [Ca2+]i transient in podocytes, potentially through the activation of TRPC6 channels. κ-OR agonist BRL52537 was used to assess the long-term effect in SS rats fed a high-salt diet. Hypertensive rats chronically treated with BRL52537 exhibited [Ca2+]i overload in podocytes, nephrinuria, albuminuria, changes in electrolyte balance, and augmented blood pressure. These data demonstrate that the κ-OR/TRPC6 signaling directly influences podocyte calcium handling, provoking the development of kidney injury in the opioid-treated hypertensive cohort.
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Affiliation(s)
- Daria Golosova
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ruslan Bohovyk
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | | | - Denisha R Spires
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Elena Isaeva
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ashraf El-Meanawy
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA .,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, WI, USA
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17
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Schunk SJ, Floege J, Fliser D, Speer T. WNT-β-catenin signalling - a versatile player in kidney injury and repair. Nat Rev Nephrol 2021; 17:172-84. [PMID: 32989282 DOI: 10.1038/s41581-020-00343-w] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2020] [Indexed: 12/11/2022]
Abstract
The WNT-β-catenin system is an evolutionary conserved signalling pathway that is of particular importance for morphogenesis and cell organization during embryogenesis. The system is usually suppressed in adulthood; however, it can be re-activated in organ injury and regeneration. WNT-deficient mice display severe kidney defects at birth. Transient WNT-β-catenin activation stimulates tissue regeneration after acute kidney injury, whereas sustained (uncontrolled) WNT-β-catenin signalling promotes kidney fibrosis in chronic kidney disease (CKD), podocyte injury and proteinuria, persistent tissue damage during acute kidney injury and cystic kidney diseases. Additionally, WNT-β-catenin signalling is involved in CKD-associated vascular calcification and mineral bone disease. The WNT-β-catenin pathway is tightly regulated, for example, by proteins of the Dickkopf (DKK) family. In particular, DKK3 is released by 'stressed' tubular epithelial cells; DKK3 drives kidney fibrosis and is associated with short-term risk of CKD progression and acute kidney injury. Thus, targeting the WNT-β-catenin pathway might represent a promising therapeutic strategy in kidney injury and associated complications.
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18
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Sebold AJ, Ahmed AS, Ryan TC, Cohen BA, Jampel HD, Suskauer SJ, Zabel TA, Comi AM, Rybczynski S. Suicide Screening in Sturge-Weber Syndrome: An Important Issue in Need of Further Study. Pediatr Neurol 2020; 110:80-86. [PMID: 32660870 DOI: 10.1016/j.pediatrneurol.2020.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/17/2020] [Accepted: 03/08/2020] [Indexed: 12/28/2022]
Abstract
BACKGROUND Sturge-Weber syndrome is a neurocutaneous disorder associated with epilepsy, glaucoma, cognitive impairments, and a port-wine birthmark. Although individuals with Sturge-Weber syndrome are vulnerable to known risk factors for suicide, including chronic illness and physical differences (port-wine birthmark), frequency of suicidal ideation and attempts, and the clinical factors associated with suicide risk, in patients with Sturge-Weber syndrome is unknown. METHODS As a part of routine hospital practice, all outpatients aged eight years and older underwent suicide risk screening during nursing triage using a standardized suicide screening tool. Suicide risk screening results, demographic variables, and medical history (as available) for patients with Sturge-Weber syndrome (N = 34; median age = 15.5; range = 8 to 47 years, 44% male) and other neurological conditions seen at the same institution (N = 369; median age = 14; range = 8 to 78 years, 66% male) were used for retrospective within- and between-group analysis. RESULTS In the combined sample of Sturge-Weber syndrome and neurologically involved patients, a positive suicide risk screen was related to Sturge-Weber syndrome diagnosis (P = 0.043); analysis by sex showed increased risk of Sturge-Weber syndrome diagnosis in males (P = 0.008), but not in females. Within the Sturge-Weber syndrome group, use of a selective serotonin reuptake inhibitor (P = 0.019) was related to a positive risk screen. CONCLUSION People with Sturge-Weber syndrome may be at greater risk of suicidal thoughts or behaviors than those with other neurological conditions. Further study of suicide risk in patients with Sturge-Weber syndrome is needed.
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Affiliation(s)
- Alison J Sebold
- Neurology, Hugo Moser Kennedy Krieger Research Institute, Baltimore, Maryland
| | - Amelia S Ahmed
- DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, Tennessee
| | - Taylor C Ryan
- Johns Hopkins University, School of Public Health, Baltimore, Maryland
| | - Bernard A Cohen
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Henry D Jampel
- Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Stacy J Suskauer
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Baltimore, Maryland; Johns Hopkins University School of Medicine, Departments of Physical Medicine and Rehabilitation, Baltimore, Maryland
| | - T Andrew Zabel
- Department of Neuropsychology, Kennedy Krieger Institute, Baltimore, Maryland; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Anne M Comi
- Neurology, Hugo Moser Kennedy Krieger Research Institute, Baltimore, Maryland; Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland.
| | - Suzanne Rybczynski
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Pediatric Rehabilitation Medicine, Kennedy Krieger Institute, Baltimore, Maryland
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19
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Abstract
Podocytes are an integral part of the glomerular filtration barrier, a structure that prevents filtration of large proteins and macromolecules into the urine. Podocyte function is dependent on actin cytoskeleton regulation within the foot processes, structures that link podocytes to the glomerular basement membrane. Actin cytoskeleton dynamics in podocyte foot processes are complex and regulated by multiple proteins and other factors. There are two key signal integration and structural hubs within foot processes that regulate the actin cytoskeleton: the slit diaphragm and focal adhesions. Both modulate actin filament extension as well as foot process mobility. No matter what the initial cause, the final common pathway of podocyte damage is dysregulation of the actin cytoskeleton leading to foot process retraction and proteinuria. Disruption of the actin cytoskeleton can be due to acquired causes or to genetic mutations in key actin regulatory and signaling proteins. Here, we describe the major structural and signaling components that regulate the actin cytoskeleton in podocytes as well as acquired and genetic causes of actin dysregulation.
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Affiliation(s)
- Judith Blaine
- Renal Division, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - James Dylewski
- Renal Division, University of Colorado Anschutz Medical Campus and Denver Health Medical Center, Aurora, CO 80045, USA
- Correspondence: ; Tel.: +303-724-4841
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20
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Abstract
Dysfunction of slit diaphragm, a cell–cell junction of glomerular podocytes, is involved in the development of proteinuria in several glomerular diseases. Slit diaphragm should be a target of a novel therapy for proteinuria. Nephrin, NEPH1, P-cadherin, FAT, and ephrin-B1 were reported to be extracellular components forming a molecular sieve of the slit diaphragm. Several cytoplasmic proteins such as ZO-1, podocin, CD2AP, MAGI proteins and Par-complex molecules were identified as scaffold proteins linking the slit diaphragm to the cytoskeleton. In this article, new insights into these molecules and the pathogenic roles of the dysfunction of these molecules were introduced. The slit diaphragm functions not only as a barrier but also as a signaling platform transfer the signal to the inside of the cell. For maintaining the slit diaphragm function properly, the phosphorylation level of nephrin is strictly regulated. The recent studies on the signaling pathway from nephrin, NEPH1, and ephrin-B1 were reviewed. Although the mechanism regulating the function of the slit diaphragm had remained unclear, recent studies revealed TRPC6 and angiotensin II-regulating mechanisms play a critical role in regulating the barrier function of the slit diaphragm. In this review, recent investigations on the regulation of the slit diaphragm function were reviewed, and a strategy for the establishment of a novel therapy for proteinuria was proposed.
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Affiliation(s)
- Hiroshi Kawachi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
| | - Yoshiyasu Fukusumi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
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21
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Wang L, Chang JH, Buckley AF, Spurney RF. Knockout of TRPC6 promotes insulin resistance and exacerbates glomerular injury in Akita mice. Kidney Int 2020; 95:321-332. [PMID: 30665571 DOI: 10.1016/j.kint.2018.09.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 09/22/2018] [Accepted: 09/27/2018] [Indexed: 12/17/2022]
Abstract
Gain-of-function mutations in TRPC6 cause familial focal segmental glomerulosclerosis, and TRPC6 is upregulated in glomerular diseases including diabetic kidney disease. We studied the effect of systemic TRPC6 knockout in the Akita model of type 1 diabetes. Knockout of TRPC6 inhibited albuminuria in Akita mice at 12 and 16 weeks of age, but this difference disappeared by 20 weeks. Knockout of TRPC6 also reduced tubular injury in Akita mice; however, mesangial expansion was significantly increased. Hyperglycemia and blood pressure were similar between TRPC6 knockout and wild-type Akita mice, but knockout mice were more insulin resistant. In cultured podocytes, knockout of TRPC6 inhibited expression of the calcium/calcineurin responsive gene insulin receptor substrate 2 and decreased insulin responsiveness. Insulin resistance is reported to promote diabetic kidney disease independent of blood glucose levels. While the mechanisms are not fully understood, insulin activates both Akt2 and ERK, which inhibits apoptosis signal regulated kinase 1 (ASK1)-p38-induced apoptosis. In cultured podocytes, hyperglycemia stimulated p38 signaling and induced apoptosis, which was reduced by insulin and ASK1 inhibition and enhanced by Akt or ERK inhibition. Glomerular p38 signaling was increased in TRPC6 knockout Akita mice and was associated with enhanced expression of the p38 gene target cyclooxygenase 2. These data suggest that knockout of TRPC6 in Akita mice promotes insulin resistance and exacerbates glomerular disease independent of hyperglycemia.
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Affiliation(s)
- Liming Wang
- Division of Nephrology, Department of Medicine, Duke University Health System, Durham, North Carolina, USA
| | - Jae-Hyung Chang
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Anne F Buckley
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, USA
| | - Robert F Spurney
- Division of Nephrology, Department of Medicine, Duke University Health System, Durham, North Carolina, USA; Durham VA Medical Center, Durham, North Carolina, USA.
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22
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Abstract
Over a decade ago, mutations in the gene encoding TRPC6 (transient receptor potential cation channel, subfamily C, member 6) were linked to development of familial forms of nephrosis. Since this discovery, TRPC6 has been implicated in the pathophysiology of non-genetic forms of kidney disease including focal segmental glomerulosclerosis (FSGS), diabetic nephropathy, immune-mediated kidney diseases, and renal fibrosis. On the basis of these findings, TRPC6 has become an important target for the development of therapeutic agents to treat diverse kidney diseases. Although TRPC6 has been a major focus for drug discovery, more recent studies suggest that other TRPC family members play a role in the pathogenesis of glomerular disease processes and chronic kidney disease (CKD). This review highlights the data implicating TRPC6 and other TRPC family members in both genetic and non-genetic forms of kidney disease, focusing on TRPC3, TRPC5, and TRPC6 in a cell type (glomerular podocytes) that plays a key role in proteinuric kidney diseases.
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23
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Hassanzadeh Khayyat N, Kim EY, Dryer SE. TRPC6 inactivation does not protect against diabetic kidney disease in streptozotocin (STZ)-treated Sprague-Dawley rats. FASEB Bioadv 2019; 1:773-782. [PMID: 32123821 PMCID: PMC6996301 DOI: 10.1096/fba.2019-00077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/06/2019] [Accepted: 10/30/2019] [Indexed: 01/14/2023] Open
Abstract
Canonical transient receptor potential-6 (TRPC6) channels have been implicated in the progression of several forms of kidney disease (1). While there is strong evidence that glomerular TRPC6 channels are dysregulated in diabetic nephropathy (DN), there is no consensus as to whether deletion or inactivation of TRPC6 is protective in animal models of DN. A previous study in Dahl salt-sensitive rats suggests that TRPC6 knockout has a modest protective effect in streptozotocin (STZ)-induced DN (2). In the present study, we examined whether inactivation of TRPC6 channels by CRISPR/Cas9 editing (Trpc6 del/del rats) affects progression of STZ-induced DN in Sprague-Dawley rats. Wild-type littermates (Trpc6 wt/wt rats) were used as controls. We observed that a single injection of STZ resulted in severe hyperglycemia that was sustained over a 10-week period, accompanied by a marked reduction in circulating C-peptide, dyslipidemia, and failure to gain weight compared to vehicle-treated animals. Those effects were equally severe in Trpc6 wt/wt and Trpc6 del/del rats. STZ treatment resulted in increased urine albumin excretion at 4, 8, and 10 weeks after injection, and this effect was equally severe in Trpc6 wt/wt and Trpc6 del/del rats. TRPC6 inactivation had no effect on blood urea nitrogen (BUN), plasma creatinine concentration, urine nephrin excretion, or kidney weight:body weight ratio measured 10 weeks after STZ injection. STZ treatment evoked modest and equivalent mesangial expansion in Trpc6 wt/wt and Trpc6 del/del rats. In summary, we observed no protective effect of TRPC6 inactivation on STZ-induced DN in rats on the Sprague-Dawley background.
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Affiliation(s)
| | - Eun Young Kim
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Stuart E. Dryer
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
- Department of Biomedical SciencesUniversity of Houston College of MedicineHoustonTXUSA
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Pablo JL, Greka A. Charting a TRP to Novel Therapeutic Destinations for Kidney Diseases. Trends Pharmacol Sci 2019; 40:911-918. [PMID: 31704171 DOI: 10.1016/j.tips.2019.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/24/2019] [Accepted: 10/07/2019] [Indexed: 12/29/2022]
Abstract
Ion channels are critical to kidney function, and their dysregulation leads to several distinct kidney diseases. Of the diversity of ion channels in kidney cells, the transient receptor potential (TRP) superfamily of proteins plays important and varied roles in both maintaining homeostasis as well as in causing disease. Recent work showed that TRPC5 blockers could successfully protect critical components of the kidney filter both in vitro and in vivo, thus revealing TRPC5 as a tractable therapeutic target for focal and segmental glomerulosclerosis (FSGS), a common cause of kidney failure. Human genetics point to three additional TRP channels as plausible therapeutic targets: TRPC6 in FSGS, PKD2 in polycystic kidney disease, and TRPM6 in familial hypomagnesemia with secondary hypocalcemia (HSH). We conclude that targeting TRP channels could pave the way for much needed therapies for kidney diseases.
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Affiliation(s)
- Juan Lorenzo Pablo
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Anna Greka
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Langfermann DS, Schmidt T, Rössler OG, Thiel G. Calcineurin controls gene transcription following stimulation of a Gαq-coupled designer receptor. Exp Cell Res 2019; 383:111553. [DOI: 10.1016/j.yexcr.2019.111553] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 08/07/2019] [Accepted: 08/10/2019] [Indexed: 01/07/2023]
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Abstract
An association of altered activity of transient receptor potential cation channel C6 (TRPC6) with the development of various diabetic complications was previously reported. In this issue, Wang et al. tested the contribution of TRPC6 in type 1 diabetes setting by breeding Akita mice with TRPC6 knockout mice. The authors revealed that the knockout of TRPC6 decreased proteinuria and attenuated tubule injury but promoted mesangial expansion in Akita mice. Therefore, TRPC6 has both beneficial and detrimental effects on glomeruli function.
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Abstract
PURPOSE OF REVIEW The underlining goal of this review is to offer a concise, detailed look into current knowledge surrounding transient receptor potential canonical channel 6 (TRPC6) in the progression of diabetic kidney disease (DKD). RECENT FINDINGS Mutations and over-activation in TRPC6 channel activity lead to the development of glomeruli injury. Angiotensin II, reactive oxygen species, and other factors in the setting of DKD stimulate drastic increases in calcium influx through the TRPC6 channel, causing podocyte hypertrophy and foot process effacement. Loss of the podocytes further promote deterioration of the glomerular filtration barrier and play a major role in the development of both albuminuria and the renal injury in DKD. Recent genetic manipulation with TRPC6 channels in various rodent models provide additional knowledge about the role of TRPC6 in DKD and are reviewed here. The TRPC6 channel has a pronounced role in the progression of DKD, with deviations in activity yielding detrimental outcomes. The benefits of targeting TRPC6 or its upstream or downstream signaling pathways in DKD are prominent.
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Affiliation(s)
- Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
- Clement J. Zablocki VA Medical Center, Milwaukee, WI, 53295, USA.
| | - Denisha Spires
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
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Lin BL, Matera D, Doerner JF, Zheng N, Del Camino D, Mishra S, Bian H, Zeveleva S, Zhen X, Blair NT, Chong JA, Hessler DP, Bedja D, Zhu G, Muller GK, Ranek MJ, Pantages L, McFarland M, Netherton MR, Berry A, Wong D, Rast G, Qian HS, Weldon SM, Kuo JJ, Sauer A, Sarko C, Moran MM, Kass DA, Pullen SS. In vivo selective inhibition of TRPC6 by antagonist BI 749327 ameliorates fibrosis and dysfunction in cardiac and renal disease. Proc Natl Acad Sci U S A 2019; 116:10156-61. [PMID: 31028142 DOI: 10.1073/pnas.1815354116] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential canonical type 6 (TRPC6) is a nonselective receptor-operated cation channel that regulates reactive fibrosis and growth signaling. Increased TRPC6 activity from enhanced gene expression or gain-of-function mutations contribute to cardiac and/or renal disease. Despite evidence supporting a pathophysiological role, no orally bioavailable selective TRPC6 inhibitor has yet been developed and tested in vivo in disease models. Here, we report an orally bioavailable TRPC6 antagonist (BI 749327; IC50 13 nM against mouse TRPC6, t1/2 8.5-13.5 hours) with 85- and 42-fold selectivity over the most closely related channels, TRPC3 and TRPC7. TRPC6 calcium conductance results in the stimulation of nuclear factor of activated T cells (NFAT) that triggers pathological cardiac and renal fibrosis and disease. BI 749327 suppresses NFAT activation in HEK293T cells expressing wild-type or gain-of-function TRPC6 mutants (P112Q, M132T, R175Q, R895C, and R895L) and blocks associated signaling and expression of prohypertrophic genes in isolated myocytes. In vivo, BI 749327 (30 mg/kg/day, yielding unbound trough plasma concentration ∼180 nM) improves left heart function, reduces volume/mass ratio, and blunts expression of profibrotic genes and interstitial fibrosis in mice subjected to sustained pressure overload. Additionally, BI 749327 dose dependently reduces renal fibrosis and associated gene expression in mice with unilateral ureteral obstruction. These results provide in vivo evidence of therapeutic efficacy for a selective pharmacological TRPC6 inhibitor with oral bioavailability and suitable pharmacokinetics to ameliorate cardiac and renal stress-induced disease with fibrosis.
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Dryer SE, Roshanravan H, Kim EY. TRPC channels: Regulation, dysregulation and contributions to chronic kidney disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1041-1066. [PMID: 30953689 DOI: 10.1016/j.bbadis.2019.04.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/13/2022]
Abstract
Mutations in the gene encoding canonical transient receptor potential-6 (TRPC6) channels result in severe nephrotic syndromes that typically lead to end-stage renal disease. Many but not all of these mutations result in a gain in the function of the resulting channel protein. Since those observations were first made, substantial work has supported the hypothesis that TRPC6 channels can also contribute to progression of acquired (non-genetic) glomerular diseases, including primary and secondary FSGS, glomerulosclerosis during autoimmune glomerulonephritis, and possibly in type-1 diabetes. Their regulation has been extensively studied, especially in podocytes, but also in mesangial cells and other cell types present in the kidney. More recent evidence has implicated TRPC6 in renal fibrosis and tubulointerstitial disease caused by urinary obstruction. Consequently TRPC6 is being extensively investigated as a target for drug discovery. Other TRPC family members are present in kidney. TRPC6 can form a functional heteromultimer with TRPC3, and it has been suggested that TRPC5 may also play a role in glomerular disease progression, although the evidence on this is contradictory. Here we review literature on the expression and regulation of TRPC6, TRPC3 and TRPC5 in various cell types of the vertebrate kidney, the evidence that these channels are dysregulated in disease models, and research showing that knock-out or pharmacological inhibition of these channels can reduce the severity of kidney disease. We also summarize several areas that remain controversial, and some of the large gaps of knowledge concerning the fundamental role of these proteins in regulation of renal function.
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Affiliation(s)
- Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; Department of Internal Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, USA.
| | - Hila Roshanravan
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
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Kim EY, Shotorbani PY, Dryer SE. TRPC6 inactivation does not affect loss of renal function in nephrotoxic serum glomerulonephritis in rats, but reduces severity of glomerular lesions. Biochem Biophys Rep 2019; 17:139-50. [PMID: 30662960 DOI: 10.1016/j.bbrep.2018.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/06/2018] [Accepted: 12/16/2018] [Indexed: 12/26/2022] Open
Abstract
Canonical transient receptor potential-6 (TRPC6) channels have been implicated in a variety of chronic kidney diseases including familial and acquired forms of focal and segmental glomerulosclerosis (FSGS) and renal fibrosis following ureteral obstruction. Here we have examined the role of TRPC6 in progression of inflammation and fibrosis in the nephrotoxic serum (NTS) model of crescentic glomerulonephritis. This was assessed in rats with non-functional TRPC6 channels due to genomic disruption of an essential domain in TRPC6 channels (Trpc6del/del rats) and wild-type littermates (Trpc6wt/wt rats). Administration of NTS evoked albuminuria and proteinuria observed 4 and 28 days later that was equally severe in Trpc6wt/wt and Trpc6del/del rats. By 28 days, there were dense deposits of complement and IgG within glomeruli in both genotypes, accompanied by severe inflammation and fibrosis readily observed by standard histological methods, and also by increases in renal cortical expression of multiple markers (α-smooth muscle actin, vimentin, NLRP3, and CD68). Tubulointerstitial fibrosis appeared equally severe in Trpc6wt/wt and Trpc6del/del rats. TRPC6 inactivation did not protect against the substantial declines in renal function (increases in blood urea nitrogen, serum creatinine and kidney:body weight ratio) in NTS-treated animals, and increases in a urine maker of proximal tubule pathology (β2-macroglobulin) were actually more severe in Trpc6del/del animals. By contrast, glomerular pathology, blindly scored from histology, and from renal cortical expression of podocin suggested a partial but significant protective effect of TRPC6 inactivation within the glomerular compartment, at least during the autologous phase of the NTS model. TRPC6 inactivation in rats does not affect declines in overall renal function in an autoimmune model of rapidly progressing glomerulonephritis. TRPC6 inactivation does not reduce renal fibrosis or tubulointerstitial disease in autoimmune glomerulonephritis, and may exacerbate proximal tubule dysfunction in this model. TRPC6 inactivation reduces glomerulosclerosis and podocyte loss in autoimmune glomerulonephritis in rats.
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Key Words
- BUN, blood urea nitrogen
- CKD, chronic kidney disease
- Chronic kidney disease
- FSGS, focal and segmental glomerulosclerosis
- GBM, glomerular basement membrane
- Glomerulonephritis
- IL-1β, interleukin 1β
- NLRP3, NOD-like receptor pyrin domain containing-3 protein
- NTS, nephrotoxic serum
- PAN, puromycin amino nucleoside
- PAS, periodic acid-Schiff’s stain
- Renal fibrosis
- SMA, α-smooth muscle actin
- TCA, trichloroacetic acid
- TNF, tumor necrosis factor
- TRPC3, canonical transient receptor potential-3 channel
- TRPC5, canonical transient receptor potential-5 channel
- TRPC6
- TRPC6, canonical transient receptor potential-6 channel
- UUO, unilateral ureteral obstruction
- suPAR, soluble urokinase receptor
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Kim EY, Hassanzadeh Khayyat N, Dryer SE. Mechanisms underlying modulation of podocyte TRPC6 channels by suPAR: Role of NADPH oxidases and Src family tyrosine kinases. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3527-36. [PMID: 30293571 DOI: 10.1016/j.bbadis.2018.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/02/2018] [Accepted: 08/06/2018] [Indexed: 01/10/2023]
Abstract
The soluble urokinase receptor (suPAR) has been implicated in the pathogenesis of chronic kidney diseases (CKD) and may function as a circulating "permeability factor" driving primary focal and segmental glomerulosclerosis (FSGS). Here we examined the mechanisms whereby suPAR causes mobilization and increased activation of Ca2+-permeable TRPC6 channels, which are also implicated in FSGS. Treatment of immortalized mouse podocytes with recombinant suPAR for 24 h caused a marked increase in cytosolic reactive oxygen species (ROS) that required signaling through integrins. This effect was associated with increased assembly of active cell surface NADPH oxidase 2 (Nox2) complexes and was blocked by the Nox2 inhibitor apoycynin. Treatment with suPAR also evoked a functionally measurable increase in TRPC6 channels that was blocked by concurrent treatment with the ROS-quencher TEMPOL as well as by inhibition of Rac1, an essential component of active Nox2 complexes. Elevated ROS evoked by exposing cells to suPAR or H2O2 caused a marked increase in the abundance of tyrosine-phosphorylated proteins including Src, and suPAR-evoked Src activation was blocked by TEMPOL. Moreover, mobilization and increased activation of TRPC6 by suPAR or H2O2 was blocked by concurrent exposure to PP2, an inhibitor of Src family tyrosine kinases. These data suggest that suPAR induces oxidative stress in podocytes that in turn drives signaling through Src family kinases to upregulate TRPC6 channels. The combination of oxidative stress and altered Ca2+ signaling may contribute to loss of podocytes and progression of various forms of CKD.
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Spires D, Ilatovskaya DV, Levchenko V, North PE, Geurts AM, Palygin O, Staruschenko A. Protective role of Trpc6 knockout in the progression of diabetic kidney disease. Am J Physiol Renal Physiol 2018; 315:F1091-F1097. [PMID: 29923767 DOI: 10.1152/ajprenal.00155.2018] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Diabetic kidney disease (DKD) is a chronic kidney pathology that leads to end-stage renal disease. Previous studies from our laboratory indicate that there is an association between the development of DKD and the transient receptor potential canonical 6 (TRPC6) channel. Trpc6 expression and activity were increased in the streptozotocin (STZ)-treated Dahl Salt-sensitive (Dahl SS) rat, an established model of type 1 diabetes. Here, using a Trpc6 knockout created on the Dahl SS rat background (SSTrpc6-/-), we test the hypothesis that the absence of Trpc6 will protect podocytes and kidney function during the development of DKD. Four groups of animals (control SSWT, SSTrpc6-/-, STZ-treated SSWT, and STZ-SSTrpc6-/-) were utilized in this study. Diabetes development was monitored for 11 wk after STZ injection with periodic weight, glucose, and urinary output measurements. There was an increase in albuminuria and glomerular injury following STZ treatment, which was not different between Dahl SS and SSTrpc6-/- groups. Western blot analysis revealed elevated levels of nephrin in urine samples of STZ-SSWT rats, which was higher compared with STZ-SSTrpc6-/- rats. Furthermore, pathological increases in basal [Ca2+]i levels and foot process damage of podocytes during the development of DKD was attenuated in the STZ-SSTrpc6-/- compared with STZ-SSWT rats. Overall, our data indicate that TRPC6 channel inhibition may have at least partial renoprotective effects, which could lead to the development of new pharmacological tools to treat or prevent the progression of DKD.
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Affiliation(s)
- Denisha Spires
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin.,Medical University of South Carolina, Department of Medicine, Charleston, South Carolina
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Paula E North
- Department of Pathology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin , Milwaukee, Wisconsin
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33
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Kim EY, Yazdizadeh Shotorbani P, Dryer SE. Trpc6 inactivation confers protection in a model of severe nephrosis in rats. J Mol Med (Berl) 2018; 96:631-44. [PMID: 29785489 DOI: 10.1007/s00109-018-1648-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/25/2018] [Accepted: 05/07/2018] [Indexed: 12/11/2022]
Abstract
Abstract Mutations in canonical transient receptor potential-6 (TRPC6) channels give rise to rare familial forms of focal and segmental glomerulosclerosis (FSGS). Here we examined a possible role for TRPC6 in the progression of chronic puromycin aminonucleoside (PAN) nephrosis in Sprague-Dawley rats, a classic model of acquired nephrotic syndromes. We used CRISPR/Cas9 technology to delete a 239-bp region within exon 2 of the Trpc6 gene (Trpc6del allele). Trpc6del/del rats expressed detectable Trpc6 transcripts missing exon 2, and TRPC6 proteins could be detected by immunoblot of renal cortex. However, the abundance of Trpc6 transcripts and TRPC6 protein in renal cortex was much lower than in Trpc6wt/wt littermates, and functional TRPC6 channels could not be detected in whole-cell recordings from glomerular cells cultured from Trpc6del/del animals, possibly because of disruption of ankyrin repeats 1 and 2. During the chronic phase of PAN nephrosis, Trpc6del/del rats had reduced urine albumin excretion, reduced serum cholesterol and triglycerides, and improved azotemia compared to wild-type Trpc6wt/wt littermates. Glomerulosclerosis was severe during chronic PAN nephrosis in Trpc6wt/wt rats but was markedly reduced in Trpc6del/del littermates. Trpc6del/del animals also had less severe tubulointerstitial fibrosis as assessed by several biochemical and histological analyses, as well as reduced foot process effacement and glomerular basement thickening compared to Trpc6wtt/wt controls. None of the manipulations in this study affected the abundance of TRPC5 channels in renal cortex. TRPC3 was increased in PAN nephrosis and in Trpc6del/del rats. These data support a role for TRPC6 channels in driving an acquired form of secondary FSGS. Key messages We examined aminonucleoside nephrosis in rats with wild type and inactivated TRPC6. TRPC6 channels were inactivated by CRISPR/Cas9 editing of the Trpc6 gene. TRPC6 inactivation reduced albuminuria in the chronic but not the acute phase. TRPC6 inactivation reduced glomerulosclerosis and ultrastructural changes. TRPC6 inactivation also reduced interstitial changes and renal fibrosis.
Electronic supplementary material The online version of this article (10.1007/s00109-018-1648-3) contains supplementary material, which is available to authorized users.
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Daehn IS. Glomerular Endothelial Cell Stress and Cross-Talk With Podocytes in Early [corrected] Diabetic Kidney Disease. Front Med (Lausanne) 2018; 5:76. [PMID: 29629372 PMCID: PMC5876248 DOI: 10.3389/fmed.2018.00076] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/07/2018] [Indexed: 12/11/2022] Open
Abstract
Diabetic kidney disease (DKD) is one of the major causes of morbidity and mortality in diabetic patients and also the leading single cause of end-stage renal disease in the United States. A large proportion of diabetic patients develop DKD and others don't, even with comparable blood glucose levels, indicating a significant genetic component of disease susceptibility. The glomerulus is the primary site of diabetic injury in the kidney, glomerular hypertrophy and podocyte depletion are glomerular hallmarks of progressive DKD, and the degree of podocyte loss correlates with severity of the disease. We know that chronic hyperglycemia contributes to both microvascular and macrovascular complications, as well as podocyte injury. We are beginning to understand the role of glomerular endothelial injury, as well as the involvement of reactive oxygen species and mitochondrial stress, which play a direct role in DKD and in other diabetic complications. There is, however, a gap in our knowledge that links genetic susceptibility to early molecular mechanisms and proteinuria in DKD. Emerging research that explores glomerular cell's specific responses to diabetes and cell cross-talk will provide mechanistic clues that underlie DKD and provide novel avenues for therapeutic intervention.
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Affiliation(s)
- Ilse Sofia Daehn
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, The Charles Bronfman Institute for Personalized Medicine, New York City, NY, United States
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Hagmann H, Mangold N, Rinschen MM, Koenig T, Kunzelmann K, Schermer B, Benzing T, Brinkkoetter PT. Proline-dependent and basophilic kinases phosphorylate human TRPC6 at serine 14 to control channel activity through increased membrane expression. FASEB J 2017; 32:208-219. [PMID: 28877958 DOI: 10.1096/fj.201700309r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/21/2017] [Indexed: 01/01/2023]
Abstract
Signaling via the transient receptor potential (TRP) ion channel C6 plays a pivotal role in hereditary and sporadic glomerular kidney disease. Several studies have identified gain-of-function mutations of TRPC6 and report induced expression and enhanced channel activity of TRPC6 in association with glomerular diseases. Interfering with TRPC6 activity may open novel therapeutic pathways. TRPC6 channel activity is controlled by protein expression and stability as well as intracellular trafficking. Identification of regulatory phosphorylation sites in TRPC6 and corresponding protein kinases is essential to understand the regulation of TRPC6 activity and may result in future therapeutic strategies. In this study, an unbiased phosphoproteomic screen of human TRPC6 identified several novel serine phosphorylation sites. The phosphorylation site at serine 14 of TRPC6 is embedded in a basophilic kinase motif that is highly conserved across species. We confirmed serine 14 as a target of MAPKs and proline-directed kinases like cyclin-dependent kinase 5 (Cdk5) in cell-based as well as in vitro kinase assays and quantitative phosphoproteomic analysis of TRPC6. Phosphorylation of TRPC6 at serine 14 enhances channel conductance by boosting membrane expression of TRPC6, whereas protein stability and multimerization of TRPC6 are not altered, making serine 14 phosphorylation a potential drug target to interfere with TRPC6 channel activity.-Hagmann, H., Mangold, N., Rinschen, M. M., Koenig, T., Kunzelmann, K., Schermer, B., Benzing, T., Brinkkoetter, P. T. Proline-dependent and basophilic kinases phosphorylate human TRPC6 at serine 14 to control channel activity through increased membrane expression.
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Affiliation(s)
- Henning Hagmann
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Nicole Mangold
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Tim Koenig
- Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; and
| | - Karl Kunzelmann
- Department of Physiology, University Regensburg, Regensburg, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany;
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Abstract
Thirty-five years ago, a third pathway for the metabolism of arachidonic acid by cytochrome P450 enzymes emerged. Subsequent work revealed that 20-hydroxyeicosatetraenoic and epoxyeicosatrienoic acids formed by these pathways have essential roles in the regulation of renal tubular and vascular function. Sequence variants in the genes that produce 20-hydroxyeicosatetraenoic acid are associated with hypertension in humans, whereas the evidence supporting a role for variants in the genes that alter levels of epoxyeicosatrienoic acids is less convincing. Studies in animal models suggest that changes in the production of cytochrome P450 eicosanoids alter BP. However, the mechanisms involved remain controversial, especially for 20-hydroxyeicosatetraenoic acid, which has both vasoconstrictive and natriuretic actions. Epoxyeicosatrienoic acids are vasodilators with anti-inflammatory properties that oppose the development of hypertension and CKD; 20-hydroxyeicosatetraenoic acid levels are elevated after renal ischemia and may protect against injury. Levels of this eicosanoid are also elevated in polycystic kidney disease and may contribute to cyst formation. Our review summarizes the emerging evidence that cytochrome P450 eicosanoids have a role in the pathogenesis of hypertension, polycystic kidney disease, AKI, and CKD.
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Affiliation(s)
- Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
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Li W, Ding Y, Smedley C, Wang Y, Chaudhari S, Birnbaumer L, Ma R. Increased glomerular filtration rate and impaired contractile function of mesangial cells in TRPC6 knockout mice. Sci Rep 2017. [PMID: 28646178 PMCID: PMC5482875 DOI: 10.1038/s41598-017-04067-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The present study was conducted to determine if TRPC6 regulates glomerular filtration rate (GFR) and the contractile function of glomerular mesangial cells (MCs). GFR was assessed in conscious TRPC6 wild type and knockout mice, and in anesthetized rats with and without in vivo knockdown of TRPC6 in kidneys. We found that GFR was significantly greater, and serum creatinine level was significantly lower in TRPC6 deficient mice. Consistently, local knockdown of TRPC6 in kidney using TRPC6 specific shRNA construct significantly attenuated Ang II-induced GFR decline in rats. Furthermore, Ang II-stimulated contraction and Ca2+ entry were significantly suppressed in primary MCs isolated from TRPC6 deficient mice, and the Ca2+ response could be rescued by re-introducing TRPC6. Moreover, inhibition of reverse mode of Na+-Ca2+ exchange by KB-R7943 significantly reduced Ca2+ entry response in TRPC6-expressing, but not in TRPC6-knocked down MCs. Ca2+ entry response was also significantly attenuated in Na+ free solution. Single knockdown of TRPC6 and TRPC1 resulted in a comparable suppression on Ca2+ entry with double knockdown of both. These results suggest that TRPC6 may regulate GFR by modulating MC contractile function through multiple Ca2+ signaling pathways.
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Affiliation(s)
- Weizu Li
- Department of Pharmacology, Anhui Medical University, Hefei, Anhui, 230032, P. R. China
| | - Yanfeng Ding
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA
| | - Crystal Smedley
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA
| | - Yanxia Wang
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA
| | - Sarika Chaudhari
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA
| | - Lutz Birnbaumer
- Transmembrane Signaling Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, 27709, USA
| | - Rong Ma
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA.
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39
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Wang L, Sha Y, Bai J, Eisner W, Sparks MA, Buckley AF, Spurney RF. Podocyte-specific knockout of cyclooxygenase 2 exacerbates diabetic kidney disease. Am J Physiol Renal Physiol 2017; 313:F430-F439. [PMID: 28490532 DOI: 10.1152/ajprenal.00614.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 05/02/2017] [Accepted: 05/09/2017] [Indexed: 01/11/2023] Open
Abstract
Enhanced expression of cyclooxygenase 2 (COX2) in podocytes contributes to glomerular injury in diabetic kidney disease, but some basal level of podocyte COX2 expression might be required to promote podocyte attachment and/or survival. To investigate the role of podocyte COX2 expression in diabetic kidney disease, we deleted COX2 specifically in podocytes in a mouse model of Type 1 diabetes mellitus (Akita mice). Podocyte-specific knockout (KO) of COX2 did not affect renal morphology or albuminuria in nondiabetic mice. Albuminuria was significantly increased in wild-type (WT) and KO Akita mice compared with nondiabetic controls, and the increase in albuminuria was significantly greater in KO Akita mice compared with WT Akita mice at both 16 and 20 wk of age. At the 20-wk time point, mesangial expansion was also increased in WT and KO Akita mice compared with nondiabetic animals, and these histologic abnormalities were not improved by KO of COX2. Tubular injury was seen only in diabetic mice, but there were no significant differences between groups. Thus, KO of COX2 enhanced albuminuria and did not improve the histopathologic features of diabetic kidney disease. These data suggest that 1) KO of COX2 in podocytes does not ameliorate diabetic kidney disease in Akita mice, and 2) some basal level of podocyte COX2 expression in podocytes is necessary to attenuate the adverse effects of diabetes on glomerular filtration barrier function.
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Affiliation(s)
- Liming Wang
- Division of Nephrology, Department of Medicine, Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina
| | - Yonggang Sha
- Division of Hematologic Malignancies and Cellular Therapy, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | | | - William Eisner
- Division of Hematological Malignancies, Department of Medicine, Duke University Medical Center, Durham, North Carolina; and
| | - Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina
| | - Anne F Buckley
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Robert F Spurney
- Division of Nephrology, Department of Medicine, Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina;
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Abstract
Podocyte and glomerular research is center stage for the development of improved preventive and therapeutic strategies for chronic progressive kidney diseases. Held April 3-6, 2016, the 11th International Podocyte Conference took place in Haifa and Jerusalem, Israel, where participants from all over the world presented their work on new developments in podocyte research. In this review, we briefly highlight the advances made in characterizing the mechanisms involved in podocyte development, metabolism, acquired injury, and repair, including progress in determining the roles of genetic variants and microRNA in particular, as well as the advances made in diagnostic techniques and therapeutics.
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Affiliation(s)
- Suheir Assady
- Department of Nephrology and Hypertension, Rambam Health Care Campus, Haifa, Israel.,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nicola Wanner
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Karl L Skorecki
- Department of Nephrology and Hypertension, Rambam Health Care Campus, Haifa, Israel; .,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Tobias B Huber
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Freiburg, Germany; .,BIOSS-Centre for Biological Signalling Studies and.,III. Medizinische Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.,ZBSA-Center for Biological Systems Analysis, Albert Ludwigs University, Freiburg, Germany; and
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41
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Ilatovskaya DV, Palygin O, Levchenko V, Endres BT, Staruschenko A. The Role of Angiotensin II in Glomerular Volume Dynamics and Podocyte Calcium Handling. Sci Rep 2017; 7:299. [PMID: 28331185 PMCID: PMC5428415 DOI: 10.1038/s41598-017-00406-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 02/27/2017] [Indexed: 02/03/2023] Open
Abstract
Podocytes are becoming a primary focus of research efforts due to their association with progressive glomeruli damage in disease states. Loss of podocytes can occur as a result of excessive intracellular calcium influx, and we have previously shown that angiotensin II (Ang II) via canonical transient receptor potential 6 (TRPC6) channels caused increased intracellular Ca2+ flux in podocytes. We showed here with patch-clamp electrophysiology that Ang II activates TRPC channels; then using confocal calcium imaging we demonstrated that Ang II–dependent stimulation of Ca2+ influx in the podocytes is precluded by blocking either AT1 or AT2 receptors (ATRs). Application of Ang(1–7) had no effect on intracellular calcium. Ang II-induced calcium flux was decreased upon inhibition of TRPC channels with SAR7334, SKF 96365, clemizole hydrochloride and La3+, but not ML204. Using a novel 3D whole-glomerulus imaging ex vivo assay, we revealed the involvement of both ATRs in controlling glomerular permeability; additionally, using specific inhibitors and activators of TRPC6, we showed that these channels are implicated in the regulation of glomerular volume dynamics. Therefore, we provide evidence demonstrating the critical role of Ang II/TRPC6 axis in the control of glomeruli function, which is likely important for the development of glomerular diseases.
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Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA
| | - Bradley T Endres
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
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42
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Ma R, Chaudhari S, Li W. Canonical Transient Receptor Potential 6 Channel: A New Target of Reactive Oxygen Species in Renal Physiology and Pathology. Antioxid Redox Signal 2016; 25:732-748. [PMID: 26937558 PMCID: PMC5079416 DOI: 10.1089/ars.2016.6661] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 02/06/2016] [Indexed: 02/07/2023]
Abstract
SIGNIFICANCE Regulation of Ca2+ signaling cascade by reactive oxygen species (ROS) is becoming increasingly evident and this regulation represents a key mechanism for control of many fundamental cellular functions. Canonical transient receptor potential (TRPC) 6, a member of Ca2+-conductive channel in the TRPC family, is widely expressed in kidney cells, including glomerular mesangial cells, podocytes, tubular epithelial cells, and vascular myocytes in renal microvasculature. Both overproduction of ROS and dysfunction of TRPC6 channel are involved in renal injury in animal models and human subjects. Although regulation of TRPC channel function by ROS has been well described in other tissues and cell types, such as vascular smooth muscle, this important cell regulatory mechanism has not been fully reviewed in kidney cells. Recent Advances: Accumulating evidence has shown that TRPC6 is a redox-sensitive channel, and modulation of TRPC6 Ca2+ signaling by altering TRPC6 protein expression or TRPC6 channel activity in kidney cells is a downstream mechanism by which ROS induce renal damage. CRITICAL ISSUES This review highlights how recent studies analyzing function and expression of TRPC6 channels in the kidney and their response to ROS improve our mechanistic understanding of oxidative stress-related kidney diseases. FUTURE DIRECTIONS Although it is evident that ROS regulate TRPC6-mediated Ca2+ signaling in several types of kidney cells, further study is needed to identify the underlying molecular mechanism. We hope that the newly identified ROS/TRPC6 pathway will pave the way to new, promising therapeutic strategies to target kidney diseases such as diabetic nephropathy. Antioxid. Redox Signal. 25, 732-748.
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Affiliation(s)
- Rong Ma
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas
| | - Sarika Chaudhari
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, Texas
| | - Weizu Li
- Department of Pharmacology, Anhui Medical University, Hefei, People's Republic of China
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Koehler S, Brähler S, Kuczkowski A, Binz J, Hackl MJ, Hagmann H, Höhne M, Vogt MC, Wunderlich CM, Wunderlich FT, Schweda F, Schermer B, Benzing T, Brinkkoetter PT. Single and Transient Ca 2+ Peaks in Podocytes do not induce Changes in Glomerular Filtration and Perfusion. Sci Rep 2016; 6:35400. [PMID: 27759104 PMCID: PMC5069688 DOI: 10.1038/srep35400] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/27/2016] [Indexed: 12/25/2022] Open
Abstract
Chronic alterations in calcium (Ca2+) signalling in podocytes have been shown to cause proteinuria and progressive glomerular diseases. However, it is unclear whether short Ca2+ peaks influence glomerular biology and cause podocyte injury. Here we generated a DREADD (Designer Receptor Exclusively Activated by a Designer Drug) knock-in mouse line to manipulate intracellular Ca2+ levels. By mating to a podocyte-specific Cre driver we are able to investigate the impact of Ca2+ peaks on podocyte biology in living animals. Activation of the engineered G-protein coupled receptor with the synthetic compound clozapine-N-oxide (CNO) evoked a short and transient Ca2+ peak in podocytes immediately after CNO administration in vivo. Interestingly, this Ca2+ peak did neither affect glomerular perfusion nor filtration in the animals. Moreover, no obvious alterations in the glomerular morphology could be observed. Taken together, these in vivo findings suggest that chronic alterations and calcium overload rather than an induction of transient Ca2+ peaks contribute to podocyte disease.
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Affiliation(s)
- Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Sebastian Brähler
- Department of Pathology &Immunology, Division of Immunobiology, Washington University School of Medicine, St Louis, USA
| | - Alexander Kuczkowski
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Julia Binz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Matthias J Hackl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Henning Hagmann
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Merly C Vogt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Department of Biological Sciences, Columbia University, New York, NY, USA
| | | | | | - Frank Schweda
- Department of Physiology, University of Regensburg, Regensburg, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
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44
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Shen X, Jiang H, Ying M, Xie Z, Li X, Wang H, Zhao J, Lin C, Wang Y, Feng S, Shen J, Weng C, Lin W, Wang H, Zhou Q, Bi Y, Li M, Wang L, Zhu T, Huang X, Lan HY, Zhou J, Chen J. Calcineurin inhibitors cyclosporin A and tacrolimus protect against podocyte injury induced by puromycin aminonucleoside in rodent models. Sci Rep 2016; 6:32087. [PMID: 27580845 DOI: 10.1038/srep32087] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 08/02/2016] [Indexed: 12/12/2022] Open
Abstract
Podocyte injury and the appearance of proteinuria are features of minimal-change disease (MCD). Cyclosporin A (CsA) and tacrolimus (FK506) has been reported to reduce proteinuria in patients with nephrotic syndrome, but mechanisms remain unknown. We, therefore, investigated the protective mechanisms of CsA and FK506 on proteinuria in a rat model of MCD induced by puromycin aminonucleoside (PAN) and in vitro cultured mouse podocytes. Our results showed that CsA and FK506 treatment decreased proteinuria via a mechanism associated to a reduction in the foot-process fusion and desmin, and a recovery of synaptopodin and podocin. In PAN-treated mouse podocytes, pre-incubation with CsA and FK506 restored the distribution of the actin cytoskeleton, increased the expression of synaptopodin and podocin, improved podocyte viability, and reduced the migrating activities of podocytes. Treatment with CsA and FK506 also inhibited PAN-induced podocytes apoptosis, which was associated with the induction of Bcl-xL and inhibition of Bax, cleaved caspase 3, and cleaved PARP expression. Further studies revealed that CsA and FK506 inhibited PAN-induced p38 and JNK signaling, thereby protecting podocytes from PAN-induced injury. In conclusion, CsA and FK506 inhibit proteinuria by protecting against PAN-induced podocyte injury, which may be associated with inhibition of the MAPK signaling pathway.
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45
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Roshanravan H, Kim EY, Dryer SE. 20-Hydroxyeicosatetraenoic Acid (20-HETE) Modulates Canonical Transient Receptor Potential-6 (TRPC6) Channels in Podocytes. Front Physiol 2016; 7:351. [PMID: 27630573 PMCID: PMC5005377 DOI: 10.3389/fphys.2016.00351] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/02/2016] [Indexed: 01/08/2023] Open
Abstract
The arachidonic acid metabolite 20-hydroxyeicosatetraenoic acid (20-HETE) regulates renal function, including changes in glomerular function evoked during tubuloglomerular feedback (TGF). This study describes the cellular actions of 20-HETE on cultured podocytes, assessed by whole-cell recordings from cultured podocytes combined with pharmacological and cell-biological manipulations of cells. Bath superfusion of 20-HETE activates cationic currents that are blocked by the pan-TRP blocker SKF-96365 and by 50 μM La3+, and which are attenuated after siRNA knockdown of TRPC6 subunits. Similar currents are evoked by a membrane-permeable analog of diacylgycerol (OAG), but OAG does not occlude responses to maximally-activating concentrations of 20-HETE (20 μM). Exposure to 20-HETE also increased steady-state surface abundance of TRPC6 subunits in podocytes as assessed by cell-surface biotinylation assays, and increased cytosolic concentrations of reactive oxygen species (ROS). TRPC6 activation by 20-HETE was eliminated in cells pretreated with TEMPOL, a membrane-permeable superoxide dismutase mimic. Activation of TRPC6 by 20-HETE was also blocked when whole-cell recording pipettes contained GDP-βS, indicating a role for either small or heterotrimeric G proteins in the transduction cascade. Responses to 20-HETE were eliminated by siRNA knockdown of podocin, a protein that organizes NADPH oxidase complexes with TRPC6 subunits in this cell type. In summary, modulation of ionic channels in podocytes may contribute to glomerular actions of 20-HETE.
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Affiliation(s)
- Hila Roshanravan
- Department of Biology and Biochemistry, University of Houston Houston, TX, USA
| | - Eun Y Kim
- Department of Biology and Biochemistry, University of Houston Houston, TX, USA
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of HoustonHouston, TX, USA; Division of Nephrology, Baylor College of MedicineHouston, TX, USA
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46
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Abstract
Despite increasing numbers of patients on dialysis, the numbers of renal transplants performed yearly have remained relatively static. During the last 50 years, there have been many advances in the pharmacology of prevention of organ rejection. However, most patients will suffer from a slow but steady decline in renal function leading to graft loss. The most common cause of long-term graft loss is chronic allograft nephropathy (CAN). Therefore, elucidating and understanding the mechanisms involved in CAN is crucial for achieving better posttransplant outcomes. It is thought that the development of epithelial to mesenchymal transition (EMT) in proximal tubules is one of the first steps towards CAN, and has been shown to be a result of cellular senescence. Cells undergoing senescence acquire a senescence associated secretory phenotype (SASP) leading to the production of interleukin-1 alpha (IL-1α), which has been implicated in several degenerative and inflammatory processes including renal disease. A central mediator in SASP activation is the production of reactive oxygen species (ROS), which are produced in response to numerous physiological and pathological stimuli. This review explores the connection between SASP and the development of EMT/CAN in an effort to suggest future directions for research leading to improved long-term graft outcomes.
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Affiliation(s)
| | - Reynold Lopez-Soler
- Albany Medical Center, Department of Surgery, Division of Transplantation, Albany, New York
| | - J Andrés Melendez
- SUNY Polytechnic Institute, Colleges of Nanoscale Science and Engineering, Albany, New York
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47
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48
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Kim JH, Xie J, Hwang KH, Wu YL, Oliver N, Eom M, Park KS, Barrezueta N, Kong ID, Fracasso RP, Huang CL, Cha SK. Klotho May Ameliorate Proteinuria by Targeting TRPC6 Channels in Podocytes. J Am Soc Nephrol 2016; 28:140-151. [PMID: 27151926 DOI: 10.1681/asn.2015080888] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 03/18/2016] [Indexed: 12/30/2022] Open
Abstract
Klotho is a type-1 membrane protein predominantly produced in the kidney, the extracellular domain of which is secreted into the systemic circulation. Membranous and secreted Klotho protect organs, including the kidney, but whether and how Klotho directly protects the glomerular filter is unknown. Here, we report that secreted Klotho suppressed transient receptor potential channel 6 (TRPC6)-mediated Ca2+ influx in cultured mouse podocytes by inhibiting phosphoinositide 3-kinase-dependent exocytosis of the channel. Furthermore, soluble Klotho reduced ATP-stimulated actin cytoskeletal remodeling and transepithelial albumin leakage in these cells. Overexpression of TRPC6 by gene delivery in mice induced albuminuria, and exogenous administration of Klotho ameliorated the albuminuria. Notably, immunofluorescence and in situ hybridization revealed Klotho expression in podocytes of mouse and human kidney. Heterozygous Klotho-deficient CKD mice had aggravated albuminuria compared with that in wild-type CKD mice with a similar degree of hypertension and reduced clearance function. Finally, disrupting the integrity of glomerular filter by saline infusion-mediated extracellular fluid volume expansion increased urinary Klotho excretion. These results reveal a potential novel function of Klotho in protecting the glomerular filter, and may offer a new therapeutic strategy for treatment of proteinuria.
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Affiliation(s)
- Ji-Hee Kim
- Departments of Physiology and Global Medical Science
| | - Jian Xie
- Division of Nephrology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Kyu-Hee Hwang
- Departments of Physiology and Global Medical Science
| | - Yueh-Lin Wu
- Division of Nephrology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.,Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; and
| | - Noelynn Oliver
- Cardiometabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut
| | | | - Kyu-Sang Park
- Departments of Physiology and Global Medical Science.,Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Nestor Barrezueta
- Cardiometabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut
| | - In-Deok Kong
- Departments of Physiology and Global Medical Science.,Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - R Paul Fracasso
- Cardiometabolic Disease Research, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut
| | - Chou-Long Huang
- Division of Nephrology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Seung-Kuy Cha
- Departments of Physiology and Global Medical Science, .,Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
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49
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Abstract
Despite the high medical burden experienced by patients with focal segmental glomerulosclerosis, the etiology of the condition remains largely unknown. Focal segmental glomerulosclerosis is highly heterogeneous in clinical and morphologic manifestations. While this presents challenges for the development of new treatments, research investments over the last 2 decades have yielded a surfeit of potential avenues for therapeutic intervention. The development of many of those ideas and concepts into new therapies, however, has been very disappointing. Here, we describe some of the factors that have potentially contributed to the poor translational performance from this research investment, including the confidence we ascribe to a target, the conduct of experimental studies, and the availability of selective reagents to test hypotheses. We will discuss the significance of genetic and systems traits as well as other methods for reducing bias. We will analyze the limitations of a successful drug development. We will use specific examples hoping that these will guide a consensus for investment and drive greater translational quality. We hope that this substrate will serve to exemplify the tremendous opportunity for intervention as well as facilitate greater collaborative effort between industry, academia, and private foundations in promoting appropriate validation of these targets. Only then will we have achieved our goal for curative therapies for this devastating disease.
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Affiliation(s)
- Nick Pullen
- Pfizer Global Research & Development, Cambridge, Massachusetts, USA.
| | - Alessia Fornoni
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, University of Miami Miller School of Medicine, Miami, Florida, USA.
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50
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Abstract
Calcium ions (Ca(2+)) are crucial for a variety of cellular functions. The extracellular and intracellular Ca(2+) concentrations are thus tightly regulated to maintain Ca(2+) homeostasis. The kidney, one of the major organs of the excretory system, regulates Ca(2+) homeostasis by filtration and reabsorption. Approximately 60% of the Ca(2+) in plasma is filtered, and 99% of that is reabsorbed by the kidney tubules. Ca(2+) is also a critical signaling molecule in kidney development, in all kidney cellular functions, and in the emergence of kidney diseases. Recently, studies using genetic and molecular biological approaches have identified several Ca(2+)-permeable ion channel families as important regulators of Ca(2+) homeostasis in kidney. These ion channel families include transient receptor potential channels (TRP), voltage-gated calcium channels, and others. In this review, we provide a brief and systematic summary of the expression, function, and pathological contribution for each of these Ca(2+)-permeable ion channels. Moreover, we discuss their potential as future therapeutic targets.
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Affiliation(s)
- Yiming Zhou
- Department of Medicine and Glom-NExT Center for Glomerular Kidney Disease and Novel Experimental Therapeutics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; and
| | - Anna Greka
- Department of Medicine and Glom-NExT Center for Glomerular Kidney Disease and Novel Experimental Therapeutics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; and The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
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