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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] [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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Ponticelli C, Moroni G, Reggiani F. Autophagy and podocytopathy. Nephrol Dial Transplant 2023; 38:1931-1939. [PMID: 36708169 DOI: 10.1093/ndt/gfad024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Indexed: 01/29/2023] Open
Abstract
Autophagy is a complex process of lysosomal-dependent degradation of unwanted cellular material. In response to endogenous or exogenous stimuli, autophagy is induced and regulated by two kinases: the AMP activated kinase and the mammalian target of rapamycin (mTOR). Cells activated by Unc-51-like kinase 1 form a double membrane complex that sequesters the cargo (phagophore) and elongates producing spherical vesicles (autophagosomes). These reach and fuse with lysosomes, which degrade the cargo (autolysosomes). The resulting macromolecules are released back and recycled in the cytosol for reuse. In the podocyte, autophagy is a homeostatic mechanism that contributes to the formation and preservation of the morphological and functional integrity of actin cytoskeleton. Podocytes, fenestrated endothelial cells and glomerular basement membrane compose the glomerular filtration barrier. Podocyte damage may cause dysfunction of the glomerular barrier, proteinuria and glomerulosclerosis in different glomerular diseases and particularly in so-called podocytopathies, namely minimal change disease and focal segmental glomerulosclerosis. Several drugs and molecules may activate autophagic function in murine models. Among them, aldosterone inhibitors, mineralocorticoid inhibitors and vitamin D3 were proven to protect podocyte from injury and reduce proteinuria in clinical studies. However, no clinical trial with autophagy regulators in podocytopathies has been conducted. Caution is needed with other autophagy activators, such as mTOR inhibitors and metformin, because of potential adverse events.
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Affiliation(s)
| | - Gabriella Moroni
- Nephrology and Dialysis Unit, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Francesco Reggiani
- Nephrology and Dialysis Unit, IRCCS Humanitas Research Hospital, Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
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Martinelli RP, Rayego-Mateos S, Alique M, Márquez-Expósito L, Tejedor-Santamaria L, Ortiz A, González-Parra E, Ruiz-Ortega M. Vitamin D, Cellular Senescence and Chronic Kidney Diseases: What Is Missing in the Equation? Nutrients 2023; 15:1349. [PMID: 36986078 PMCID: PMC10056834 DOI: 10.3390/nu15061349] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/12/2023] Open
Abstract
As life expectancy increases in many countries, the prevalence of age-related diseases also rises. Among these conditions, chronic kidney disease is predicted to become the second cause of death in some countries before the end of the century. An important problem with kidney diseases is the lack of biomarkers to detect early damage or to predict the progression to renal failure. In addition, current treatments only retard kidney disease progression, and better tools are needed. Preclinical research has shown the involvement of the activation of cellular senescence-related mechanisms in natural aging and kidney injury. Intensive research is searching for novel treatments for kidney diseases as well as for anti-aging therapies. In this sense, many experimental shreds of evidence support that treatment with vitamin D or its analogs can exert pleiotropic protective effects in kidney injury. Moreover, vitamin D deficiency has been described in patients with kidney diseases. Here, we review recent evidence about the relationship between vitamin D and kidney diseases, explaining the underlying mechanisms of the effect of vitamin D actions, with particular attention to the modulation of cellular senescence mechanisms.
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Affiliation(s)
- Romina P. Martinelli
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz-Universidad Autónoma, 28040 Madrid, Spain
| | - Sandra Rayego-Mateos
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz-Universidad Autónoma, 28040 Madrid, Spain
- Ricors2040, 28029 Madrid, Spain
| | - Matilde Alique
- Ricors2040, 28029 Madrid, Spain
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, 28871 Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28034 Madrid, Spain
| | - Laura Márquez-Expósito
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz-Universidad Autónoma, 28040 Madrid, Spain
- Ricors2040, 28029 Madrid, Spain
| | - Lucia Tejedor-Santamaria
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz-Universidad Autónoma, 28040 Madrid, Spain
- Ricors2040, 28029 Madrid, Spain
| | - Alberto Ortiz
- Ricors2040, 28029 Madrid, Spain
- Department of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz-Universidad Autónoma Madrid, 28040 Madrid, Spain
| | - Emilio González-Parra
- Ricors2040, 28029 Madrid, Spain
- Department of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz-Universidad Autónoma Madrid, 28040 Madrid, Spain
| | - Marta Ruiz-Ortega
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz-Universidad Autónoma, 28040 Madrid, Spain
- Ricors2040, 28029 Madrid, Spain
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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: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [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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Liao TH, Wu HC, Liao MT, Hu WC, Tsai KW, Lin CC, Lu KC. The Perspective of Vitamin D on suPAR-Related AKI in COVID-19. Int J Mol Sci 2022; 23:ijms231810725. [PMID: 36142634 PMCID: PMC9500944 DOI: 10.3390/ijms231810725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 01/08/2023] Open
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of millions of people around the world. Severe vitamin D deficiency can increase the risk of death in people with COVID-19. There is growing evidence that acute kidney injury (AKI) is common in COVID-19 patients and is associated with poorer clinical outcomes. The kidney effects of SARS-CoV-2 are directly mediated by angiotensin 2-converting enzyme (ACE2) receptors. AKI is also caused by indirect causes such as the hypercoagulable state and microvascular thrombosis. The increased release of soluble urokinase-type plasminogen activator receptor (suPAR) from immature myeloid cells reduces plasminogen activation by the competitive inhibition of urokinase-type plasminogen activator, which results in low plasmin levels and a fibrinolytic state in COVID-19. Frequent hypercoagulability in critically ill patients with COVID-19 may exacerbate the severity of thrombosis. Versican expression in proximal tubular cells leads to the proliferation of interstitial fibroblasts through the C3a and suPAR pathways. Vitamin D attenuates the local expression of podocyte uPAR and decreases elevated circulating suPAR levels caused by systemic inflammation. This decrease preserves the function and structure of the glomerular barrier, thereby maintaining renal function. The attenuated hyperinflammatory state reduces complement activation, resulting in lower serum C3a levels. Vitamin D can also protect against COVID-19 by modulating innate and adaptive immunity, increasing ACE2 expression, and inhibiting the renin–angiotensin–aldosterone system. We hypothesized that by reducing suPAR levels, appropriate vitamin D supplementation could prevent the progression and reduce the severity of AKI in COVID-19 patients, although the data available require further elucidation.
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Affiliation(s)
- Tzu-Hsien Liao
- Department of Chinese Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
| | - Hsien-Chang Wu
- Department of Chinese Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
- School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien 970, Taiwan
| | - Min-Tser Liao
- Department of Pediatrics, Taoyuan Armed Forces General Hospital Hsinchu Branch, Hsinchu City 300, Taiwan
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Wan-Chung Hu
- Department of Clinical Pathology and Medical Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
| | - Kuo-Wang Tsai
- Department of Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
| | - Ching-Chieh Lin
- Department of Chest Medicine, Taoyuan Armed Forces General Hospital Hsinchu Branch, Hsinchu City 300, Taiwan
| | - Kuo-Cheng Lu
- Division of Nephrology, Department of Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 242, Taiwan
- Correspondence:
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Vitamin D and Glomerulonephritis. ACTA ACUST UNITED AC 2021; 57:medicina57020186. [PMID: 33671780 PMCID: PMC7926883 DOI: 10.3390/medicina57020186] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/14/2021] [Accepted: 02/16/2021] [Indexed: 12/11/2022]
Abstract
Vitamin D presents a plethora of different functions that go beyond its role in skeletal homeostasis. It is an efficient endocrine regulator of the Renin–Angiotensin–Aldosterone System (RAAS) and erythropoiesis, exerts immunomodulatory effects, reduces the cardiovascular events and all-cause mortality. In Chronic Kidney Disease (CKD) patients, Vitamin D function is impaired; the renal hydrolyzation of its inactive form by the action of 1α-hydroxylase declines at the same pace of reduced nephron mass. Moreover, Vitamin D major carrier, the D-binding protein (DBP), is less represented due to Nephrotic Syndrome (NS), proteinuria, and the alteration of the cubilin–megalin–amnionless receptor complex in the renal proximal tubule. In Glomerulonephritis (GN), Vitamin D supplementation demonstrated to significantly reduce proteinuria and to slow kidney disease progression. It also has potent antiproliferative and immunomodulating functions, contributing to the inhibitions of kidney inflammation. Vitamin D preserves the structural integrity of the slit diaphragm guaranteeing protective effects on podocytes. Activated Vitamin D has been demonstrated to potentiate the antiproteinuric effect of RAAS inhibitors in IgA nephropathy and Lupus Nephritis, enforcing its role in the treatment of glomerulonephritis: calcitriol treatment, through Vitamin D receptor (VDR) action, can regulate the heparanase promoter activity and modulate the urokinase receptor (uPAR), guaranteeing podocyte preservation. It also controls the podocyte distribution by modulating mRNA synthesis and protein expression of nephrin and podocin. Maxalcalcitol is another promising alternative: it has about 1/600 affinity to vitamin D binding protein (DBP), compared to Calcitriol, overcoming the risk of hypercalcemia, hyperphosphatemia and calcifications, and it circulates principally in unbound form with easier availability for target tissues. Doxercalciferol, as well as paricalcitol, showed a lower incidence of hypercalcemia and hypercalciuria than Calcitriol. Paricalcitol demonstrated a significant role in suppressing RAAS genes expression: it significantly decreases angiotensinogen, renin, renin receptors, and vascular endothelial growth factor (VEGF) mRNA levels, thus reducing proteinuria and renal damage. The purpose of this article is to establish the Vitamin D role on immunomodulation, inflammatory and autoimmune processes in GN.
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Stratford K, Haykal-Coates N, Thompson L, Farraj A, Hazari M. Early-life persistent vitamin D deficiency-induced cardiovascular dysfunction in mice is mediated by transient receptor potential C channels. J Steroid Biochem Mol Biol 2021; 206:105804. [PMID: 33338589 PMCID: PMC9152789 DOI: 10.1016/j.jsbmb.2020.105804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Studies indicate that chronic vitamin D deficiency (VDD) may predispose to hypertension, yet, there is very little data characterizing its direct cardiac effects. Vitamin D modulates the function of transient receptor potential C cation channels (TRPC), which is a mechanosensitive cation channel that plays a role in cardiac slow-force responses to hemodynamic changes. The purpose of this study was to determine the cardiac effects of VDD and the potential role of TRPC. METHODS Three-week old mice were placed on a VDD or normal diet (ND) for 19 weeks. Mice were then implanted with radiotelemeters for the measurement of heart rate (HR) and heart rate variability (HRV), while a separate group was anesthetized to measure blood pressure (BP) and left ventricular function using an intraventricular probe. Animals were treated with a TRPC antagonist or vehicle after which they were challenged with dobutamine to measure cardiac responses. RESULTS VDD mice had significantly increased BP (72 ± 3 mmHg vs. 62 ± 2 mmHg) and left ventricular pressure (LVP) (84.6 ± 0.8 mmHg vs. 78.2 ± 2.0 mmHg), and decreased cardiac contractility (-3 % vs. + 11 %) and HR response (+8 % vs. + 13 %) to dobutamine when compared to ND. These responses were blocked by the TRPC antagonist. HRV decreased with increasing dobutamine doses in ND but not VDD mice, however, the antagonist had no effect. CONCLUSION VDD increases BP and alters cardiac mechanical function in mice, the latter appears to be mediated by TRPC, in particular TRPC6. Although the cardiac effects might be due to increased BP, it is likely that VDD also affects the function of the heart directly. This is the first study to demonstrate the potentially deleterious effects of VDD on cardiac function and the role of TRPC6 in this response.
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Affiliation(s)
- Kimberly Stratford
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina - Chapel Hill, Chapel Hill, NC, 27599, United States
| | - Najwa Haykal-Coates
- Inhalation Toxicology Facilities Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, United States
| | - Leslie Thompson
- Cardiopulmonary and Immunotoxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, United States
| | - Aimen Farraj
- Cardiopulmonary and Immunotoxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, United States
| | - Mehdi Hazari
- Cardiopulmonary and Immunotoxicology Branch, Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, United States.
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Miller MS, Rudinsky AJ, Klamer BG, Chew DJ, Parker VJ. Association between vitamin D metabolites, vitamin D binding protein, and proteinuria in dogs. J Vet Intern Med 2020; 34:2468-2477. [PMID: 33026128 PMCID: PMC7694856 DOI: 10.1111/jvim.15912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 09/02/2020] [Accepted: 09/16/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Proteinuria has been associated with progression of renal disease and increased morbidity and mortality in dogs and people. In people, proteinuria also has been associated with hypovitaminosis D. Little is known about the relationship between vitamin D metabolism and proteinuria in dogs. OBJECTIVES To further elucidate vitamin D status in dogs with protein-losing nephropathy (PLN) and minimal to no azotemia. We hypothesized that vitamin D metabolites would be lower in dogs with PLN compared to healthy dogs. ANIMALS Twenty-three client-owned adult dogs with PLN and 10 healthy control dogs. METHODS Serum 25-hydroxyvitamin D (25[OH]D), 1,25-dihydroxyvitamin D (1,25[OH]2 D), 24,25-dihydroxyvitamin D (24,25[OH]2 D), serum vitamin D binding protein (VDBP), and urine 25(OH)D concentrations were measured. RESULTS Compared to healthy dogs, dogs with PLN had lower concentrations of all vitamin D metabolites (P < .01). Correlations (rho; 95% confidence interval [CI]) in dogs with PLN are reported. Serum 25(OH)D and 24,25(OH)2 D concentrations were positively correlated with albumin (r = 0.47; 0.07-0.74), and 24,25(OH)2 D was negatively correlated with urine protein-to-creatinine ratio (UPC; r = -0.54; -0.78 to -0.16). Urine 25(OH)D-to-creatinine ratio was negatively correlated with serum albumin concentration (r = -0.77; -0.91 to -0.50) and positively correlated with UPC (r = 0.79; 0.53-0.91). Serum VDBP concentration was positively correlated with serum albumin concentration (r = 0.53; 0.05-0.81). CONCLUSIONS AND CLINICAL IMPORTANCE Dogs with PLN have decreased serum concentrations of vitamin D metabolites. Urine 25(OH)D-to-creatinine ratio and UPC are correlated in PLN dogs. Future studies are needed to assess additional management strategies for dogs with PLN.
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Affiliation(s)
- Matthew S Miller
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Adam J Rudinsky
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Brett G Klamer
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - Dennis J Chew
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
| | - Valerie J Parker
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
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Abstract
Nuclear receptors have a broad spectrum of biological functions in normal physiology and in the pathology of various diseases, including glomerular disease. The primary therapies for many glomerular diseases are glucocorticoids, which exert their immunosuppressive and direct podocyte protective effects via the glucocorticoid receptor (GR). As glucocorticoids are associated with important adverse effects and a substantial proportion of patients show resistance to these therapies, the beneficial effects of selective GR modulators are now being explored. Peroxisome proliferator-activated receptor-γ (PPARγ) agonism using thiazolidinediones has potent podocyte cytoprotective and nephroprotective effects. Repurposing of thiazolidinediones or identification of novel PPARγ modulators are potential strategies to treat non-diabetic glomerular disease. Retinoic acid receptor-α is the key mediator of the renal protective effects of retinoic acid, and repair of the endogenous retinoic acid pathway offers another potential therapeutic strategy for glomerular disease. Vitamin D receptor, oestrogen receptor and mineralocorticoid receptor modulators regulate podocyte injury in experimental models. Further studies are needed to better understand the mechanisms of these nuclear receptors, evaluate their synergistic pathways and identify their novel modulators. Here, we focus on the role of nuclear receptors in podocyte biology and non-diabetic glomerular disease.
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Jardin I, Nieto J, Salido GM, Rosado JA. TRPC6 channel and its implications in breast cancer: an overview. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118828. [PMID: 32822726 DOI: 10.1016/j.bbamcr.2020.118828] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 08/13/2020] [Indexed: 12/11/2022]
Abstract
TRPC6 channel is widely expressed in most human tissues and participates in a number of physiological processes. TRPC6 belongs to the DAG-activated subfamily of channels, but has also been postulated as a mediator in the store-operated calcium entry pathway. The recent characterization of TRPC6 crystal structure has granted a wonderful tool to finally dissect and understand TRPC6 physiological and biophysical properties. Growing evidences have demonstrated that the pattern of expression of TRPC6 proteins is upregulated in several pathophysiological conditions, including breast cancer. However, the real role of TRPC6 in breast cancer persists still unknown. Here we present the current state of the art concerning the function and significance of TRPC6 in this disease. Future investigations should be focus in the creation and identification of compounds that specifically target the channel to ameliorate TRPC6-related diseases.
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Affiliation(s)
- Isaac Jardin
- Cellular Physiology Research Group, Department of Physiology, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain.
| | - Joel Nieto
- Cellular Physiology Research Group, Department of Physiology, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Ginés M Salido
- Cellular Physiology Research Group, Department of Physiology, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
| | - Juan A Rosado
- Cellular Physiology Research Group, Department of Physiology, Institute of Molecular Pathology Biomarkers, University of Extremadura, 10003 Caceres, Spain
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Hall G, Wang L, Spurney RF. TRPC Channels in Proteinuric Kidney Diseases. Cells 2019; 9:cells9010044. [PMID: 31877991 PMCID: PMC7016871 DOI: 10.3390/cells9010044] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 12/20/2022] Open
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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12
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Wu CC, Liao MT, Hsiao PJ, Lu CL, Hsu YJ, Lu KC, Chu P. Antiproteinuria Effect of Calcitriol in Patients With Chronic Kidney Disease and Vitamin D Deficiency: A Randomized Controlled Study. J Ren Nutr 2019; 30:200-207. [PMID: 31704188 DOI: 10.1053/j.jrn.2019.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 07/27/2019] [Accepted: 09/01/2019] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Vitamin D has been demonstrated to lessen proteinuria severity in chronic kidney disease (CKD). Compared with healthy populations, patients with CKD may have lower serum levels of 1,25-dihydroxy vitamin D (1,25-(OH)2 D) and 25-hydroxy vitamin D (25-(OH) D). We investigated the effect of oral low-dose active vitamin D (calcitriol at 0.25 μg, 3 times weekly) on urinary protein excretion. DESIGN AND METHODS We conducted a nonblinded and non-placebo-controlled study. In total, 60 patients with CKD (average estimated glomerular filtration rate of >15 mL/min) who received a stable dose of angiotensin receptor blocker (ARB) or angiotensin-converting enzyme inhibitor (ACEI) were enrolled in this 24-week study. We randomly assigned these patients to the vitamin D group (oral calcitriol at 0.25 μg 3 times weekly with an ACEI or ARB) or the control group (ACEI or ARB). Change in the urine protein/creatinine ratio (uPCR) was the primary endpoint in this study. RESULTS The mean baseline uPCRs of the 2 groups were comparable (1.84 ± 0.83 g/g vs. 2.02 ± 0.97 g/g, control vs. vitamin D group; P = .46). After the 24-week treatment, the uPCRs were significantly lower than the baseline values in the vitamin D group (1.35 ± 0.64 g/g; P < .05) but not in the control group. The values of uPCR decreased significantly at 8, 16, and 24 weeks (P < .05 vs. baseline) in the vitamin D group. The values of uPCRs were significantly lower in the vitamin D group than in the control group at 8, 16, and 24 weeks (P < .05). A positive correlation was discovered between reduction in uPCRs at 24-week and baseline 25-(OH) D serum level in the vitamin D group (r = 0.738, P < .001). CONCLUSION Supplementary low-dose active vitamin D could reduce proteinuria in CKD patients with low serum 25-(OH) D levels.
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Affiliation(s)
- Chia-Chao Wu
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Min-Tser Liao
- Department of Pediatrics, Taoyuan Armed Forces General Hospital, Taoyuan City, Taiwan; Division of Pediatrics, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Po-Jen Hsiao
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 242, Taiwan; Department of Internal Medicine, Taoyuan Armed Forces General Hospital, Taoyuan City, Taiwan; Department of Life Sciences, National Central University, Taoyuan City, Taiwan
| | - Chien-Lin Lu
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 242, Taiwan
| | - Yu-Juei Hsu
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Kuo-Cheng Lu
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 242, Taiwan
| | - Pauling Chu
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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13
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Lu XY, Liu BC, Cao YZ, Song C, Su H, Chen G, Klein JD, Zhang HX, Wang LH, Ma HP. High glucose reduces expression of podocin in cultured human podocytes by stimulating TRPC6. Am J Physiol Renal Physiol 2019; 317:F1605-F1611. [PMID: 31566428 DOI: 10.1152/ajprenal.00215.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The transient receptor potential canonical 6 (TRPC6) channel and podocin are colocalized in the glomerular slit diaphragm as an important complex to maintain podocyte function. Gain of TRPC6 function and loss of podocin function induce podocyte injury. We have previously shown that high glucose induces apoptosis of podocytes by activating TRPC6; however, whether the activated TRPC6 can alter podocin expression remains unknown. Western blot analysis and confocal microscopy were used to examine both expression levels of TRPC6, podocin, and nephrin and morphological changes of podocytes in response to high glucose. High glucose increased the expression of TRPC6 but reduced the expression of podocin and nephrin, in both cultured human podocytes and type 1 diabetic rat kidneys. The decreased podocin was diminished in TRPC6 knockdown podocytes. High glucose elevated intracellular Ca2+ in control podocytes but not in TRPC6 knockdown podocytes. High glucose also elevated the expression of a tight junction protein, zonula occludens-1, and induced the redistribution of zonula occludens-1 and loss of podocyte processes. These data together suggest that high glucose reduces protein levels of podocin by activating TRPC6 and induces morphological changes of cultured podocytes.
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Affiliation(s)
- Xiao-Yu Lu
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Bing-Chen Liu
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.,Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Yu-Ze Cao
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Neurology, Peking Union Medical College Hospital, Beijing, People's Republic of China
| | - Chang Song
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Hua Su
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Guangping Chen
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Janet D Klein
- Department of Medicine, Renal Division, Emory University School of Medicine, Atlanta, Georgia
| | - Hui-Xue Zhang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li-Hua Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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14
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Fayed A, El Nokeety MM, Heikal AA, Sadek KM, Hammad H, Abdulazim DO, Salem MM, Sharaf El Din UA. Urine albumin and serum uric acid are important determinants of serum 25 hydroxyvitamin D level in pre-dialysis chronic kidney disease patients. Ren Fail 2019; 41:540-546. [PMID: 31234687 PMCID: PMC6598477 DOI: 10.1080/0886022x.2018.1563552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Low serum 25 hydroxyvitamin D (25 OH D) is common among chronic kidney disease (CKD) patients. This cross-sectional study is looking for the different factors associated with serum 25 OH D among pre-dialysis CKD. 1624 adult stage 3–5 CKD patients were studied beside 200 normal control subjects. All candidates were tested for body mass index (BMI), estimated glomerular filtration rate (eGFR), calcium (Ca), phosphorus (P), parathormone (PTH), 25 OH D, albumin, and uric acid (UA), and urine albumin/creatinine ratio (ACR). Multivariate linear regression analysis was done to determine predictors of 25 OH D. 98.6% of CKD patients have inadequate level of 25 OH D vs 48% of normal subjects. Serum 25 OH D was significantly lower in CKD patients (mean ± S.D = 16.54 ± 5.8 vs 37.79 ± 3.58 ng/mL for CKD vs control group respectively, p < .001). Serum level of 25 OH D has significant positive correlation with Ca (r = 0.337, p < .001), and significant negative correlation with P, PTH, UA, and ACR (r = −0.440, −0. 679, −0.724, and −0.781respectively, p < .001 in all). The independent predictors of 25 OH D were Ca, P, UA, PTH, and ACR (R square = 0.7, β = −0.087, −0.226, −0.313, −0.253, and −0.33 respectively, p < .001 in all). In conclusion, pre-dialysis CKD patients frequently suffer low 25 OH D. Among the different abnormalities related to CKD, urine albumin excretion rate and UA are the most important predictors of 25 OH D in these patients.
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Affiliation(s)
- Ahmed Fayed
- a Nephrology Unit, Internal Medicine Department , School of Medicine, Cairo University , Manial , Egypt
| | - Mahmoud M El Nokeety
- a Nephrology Unit, Internal Medicine Department , School of Medicine, Cairo University , Manial , Egypt
| | - Ahmed A Heikal
- b Internal Medicine Department, School of Medicine , Cairo University , Manial , Egypt
| | - Khaled M Sadek
- a Nephrology Unit, Internal Medicine Department , School of Medicine, Cairo University , Manial , Egypt
| | - Hany Hammad
- a Nephrology Unit, Internal Medicine Department , School of Medicine, Cairo University , Manial , Egypt
| | - Dina O Abdulazim
- c Rheumatology and Rehabilitation Department, School of Medicine , Cairo University , Manial , Egypt
| | - Mona M Salem
- d Endocrinology Unit, Internal Medicine Department, School of Medicine , Cairo University , Manial , Egypt
| | - Usama A Sharaf El Din
- a Nephrology Unit, Internal Medicine Department , School of Medicine, Cairo University , Manial , Egypt
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15
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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: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [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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16
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Yu Q, Qiao Y, Liu D, Liu F, Gao C, Duan J, Liang L, Di X, Yuan Y, Gao Y, Cui S, Qin Y, Li T, Zheng Z, Liu Z. Vitamin D protects podocytes from autoantibodies induced injury in lupus nephritis by reducing aberrant autophagy. Arthritis Res Ther 2019; 21:19. [PMID: 30635032 PMCID: PMC6330406 DOI: 10.1186/s13075-018-1803-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/20/2018] [Indexed: 11/20/2022] Open
Abstract
Subject The aim of this study was to investigate whether vitamin D plays a protective role in podocyte injury induced by autoantibodies purified from the serum of patients with lupus nephritis (LN) via reducing aberrant autophagy. Methods Autophagic activities of renal tissues of patients with LN were evaluated under transmission electronic microscope (TEM). Immunoglobulin G (IgG) from patients with LN was purified to induce human podocyte injury, and the role of vitamin D in injury was observed. Podocytes were observed under TEM, autophagic activity was evaluated by western blot analysis and quantitative real-time polymerase chain reaction, and mRFP-GFP-LC3B adenovirus was infected into human podocytes in vitro. Results Significantly higher autophagic levels were observed in patients with LN (P <0.05), and apparently greater autophagic levels in podocytes were shown (P <0.05). Among different classifications of LN, class V (n = 5), III + V (n = 5), and IV + V (n = 5) gained higher autophagic levels than class III (n = 5) and IV (n = 5). Induced autophagy, which was evident by increased LC3B-II and Beclin 1 level, caused consumption of p62, more autophagosomes observed under TEM, and more LC3B dots observed under confocal microscope in the IgG group, along with decreased nephrin expression, which suggests podocyte injury. Reduction of autophagy as well as alleviated podocyte injury was observed in the IgG+ vitamin D group. Conclusion This study demonstrates that vitamin D plays a protective role in podocyte injury induced by autoantibodies from patients with LN and appears to be a novel therapy target in LN.
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Affiliation(s)
- Qi Yu
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China.,Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Yingjin Qiao
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China.,Institute of Nephrology, Blood Purification Center, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Dongwei Liu
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Fengxun Liu
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Congcong Gao
- Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Jiayu Duan
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Lulu Liang
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Xueqi Di
- Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Yi Yuan
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Yukui Gao
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Siwan Cui
- Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Yilu Qin
- Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Tianfang Li
- Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China
| | - Zhaohui Zheng
- Department of Rheumatology, The First Affiliated Hospital of Zhengzhou University, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China.
| | - Zhangsuo Liu
- Department of Nephrology, Research Institute of Nephrology, Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Core Unit of National Clinical Medical Research Center of Kidney Disease, The First Affiliated Hospital of Zhengzhou University, Nephrology, 1 Easten Jianshe Road, Zhengzhou, 450052, Henan, People's Republic of China.
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17
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Czaya B, Seeherunvong W, Singh S, Yanucil C, Ruiz P, Quiroz Y, Grabner A, Katsoufis C, Swaminathan S, Abitbol C, Rodriguez-Iturbe B, Faul C, Freundlich M. Cardioprotective Effects of Paricalcitol Alone and in Combination With FGF23 Receptor Inhibition in Chronic Renal Failure: Experimental and Clinical Studies. Am J Hypertens 2019; 32:34-44. [PMID: 30329020 DOI: 10.1093/ajh/hpy154] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/13/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND In uremic animals, vitamin D receptor (VDR) agonists like paricalcitol (Pc) attenuate cardiac hypertrophy, but this effect has not been replicated consistently in humans with chronic kidney disease. Elevated fibroblast growth factor 23 (FGF23) levels cause cardiac hypertrophy with activation of the myocardial calcineurin/nuclear factor of activated T cell (NFAT) axis and may antagonize the cardioprotective effects of VDR agonist therapy. We hypothesized that the effectiveness of Pc may depend on the prevailing circulating levels of FGF23 and could be potentiated by the combined administration of a pan-FGF23 receptor (FGFR) blocker agent (PD173074). METHODS In rats with 5/6 nephrectomy treated with Pc or PD173074 or both agents concurrently, myocardial mRNA expression of renin-angiotensin system, VDR, FGFR4, and calcineurin/NFAT target genes was determined. In adolescents on hemodialysis, we analyzed sequential echocardiograms, blood pressures and serial FGF23 measurements, and their relations to the cumulative administered dose of parenteral Pc. RESULTS The ratio of Pc dose/plasma levels of FGF23 correlated inversely (P < 0.005) with the cardiac mass in uremic rats and in hemodialysis patients, independently of hypertension. Despite persistently elevated FGF23 levels and myocardial FGFR4 activation, Pc suppressed upregulated myocardial calcineurin/NFAT target genes, and the effects were amplified by coadministration of PD173074. CONCLUSIONS The beneficial effects of Pc on uremic cardiac hypertrophy are counterbalanced by the increased FGF23 levels. Blockade of FGF23-mediated signaling increased the Pc-induced suppression of the myocardial calcineurin/NFAT system. Higher doses of Pc should be considered in the treatment of patients with uremic cardiomyopathy.
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Affiliation(s)
- Brian Czaya
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Wacharee Seeherunvong
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Saurav Singh
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Christopher Yanucil
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Phillip Ruiz
- Department of Surgery and Immunopathology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Yasmir Quiroz
- Hospital Universitario, Servicio de Nefrologia y Laboratorio de Inmunobiologia, Instituto Venezolano de Investigaciones Científicas (IVIC)-Zulia, Maracaibo, Venezuela
| | - Alexander Grabner
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Chryso Katsoufis
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Sethuraman Swaminathan
- Division of Pediatric Cardiology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Carolyn Abitbol
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Bernardo Rodriguez-Iturbe
- Hospital Universitario, Servicio de Nefrologia y Laboratorio de Inmunobiologia, Instituto Venezolano de Investigaciones Científicas (IVIC)-Zulia, Maracaibo, Venezuela
| | - Christian Faul
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michael Freundlich
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, Miami, Florida, USA
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18
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Zhang L, Chen XP, Qin H, Jiang L, Qin YH. ATRA attenuate proteinuria via downregulation of TRPC6 in glomerulosclerosis rats induced by adriamycin. Ren Fail 2018; 40:266-272. [PMID: 29619864 PMCID: PMC6014515 DOI: 10.1080/0886022x.2018.1456459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Objective: In this research, we explored the molecular mechanism of proteinuria in glomerulosclerosis rats and the protective effects of ATRA. Methods: This research set up three groups: SHO group, GS group, and ATRA group (15 mg/(kg d), Sigma, St. Louis, MO). The serum creatinine (Scr), urea nitrogen (BUN), and 24-h proteinuria were detected 12 weeks after administration of ATRA. The pathological and ultrastructure changes were observed under light microscope and transmission electron microscope. The protein expression of TGF-β1 and Col-IV in glomerulus was detected by immunohitochemistry method. The mRNA and the protein expression of glomerular TRPC6 were detected by RT-PCR and Western blot. Results: In the rat model of GS, the expressions of TRPC6 were significantly elevated compared with the normal rat group; however, the use of ATRA down-regulated the expression of TRPC6 in the glomeruli and attenuated glomerulosclerosis and proteinuria. Scr and BUN were also improved by the treatment of ATRA. Conclusions: Our results demonstrated that ATRA could ameliorate glomerulosclerosis and proteinuria in GS, which may be related to suppressed expression of TRPC6.
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Affiliation(s)
- Lei Zhang
- a Department of Pediatric Nephrology , The First Affiliated Hospital of GuangXi Medical University , Nanning , China.,b Department of Pediatric , Affiliated Hospital of Hebei University , Baoding , China
| | - Xiu-Ping Chen
- a Department of Pediatric Nephrology , The First Affiliated Hospital of GuangXi Medical University , Nanning , China
| | - He Qin
- a Department of Pediatric Nephrology , The First Affiliated Hospital of GuangXi Medical University , Nanning , China
| | - Ling Jiang
- a Department of Pediatric Nephrology , The First Affiliated Hospital of GuangXi Medical University , Nanning , China
| | - Yuan-Han Qin
- a Department of Pediatric Nephrology , The First Affiliated Hospital of GuangXi Medical University , Nanning , China
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19
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Verheijden KAT, Sonneveld R, Bakker-van Bebber M, Wetzels JFM, van der Vlag J, Nijenhuis T. The Calcium-Dependent Protease Calpain-1 Links TRPC6 Activity to Podocyte Injury. J Am Soc Nephrol 2018; 29:2099-2109. [PMID: 29954830 DOI: 10.1681/asn.2016111248] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 06/08/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The hallmark of podocytopathies, such as FSGS, is podocyte injury resulting in proteinuria. Transient receptor potential channel C6 (TRPC6) is a calcium-conducting ion channel expressed at the slit diaphragm. TRPC6 gain-of-function mutations and glomerular TRPC6 overexpression are associated with proteinuria. However, the pathways linking TRPC6 to podocyte injury, which is characterized by loss of the slit diaphragm protein nephrin, activation of several intracellular pathways (including calcineurin-NFAT signaling), and cytoskeletal rearrangement, remain elusive. METHODS We tested whether the calcium-dependent protease calpain-1 mediates TRPC6-dependent podocyte injury in human and experimental FSGS and cultured podocytes. RESULTS Compared with kidneys of healthy controls, kidneys of patients with FSGS had increased TRPC6 expression, increased calpain and calcineurin activity, and reduced expression of the calpain target Talin-1, which links the actin cytoskeleton to integrins and is critical for podocyte cytoskeletal stability. In a rat model of human FSGS, increased glomerular and urinary calpain activity associated with reduced Talin-1 abundance, enhanced calcineurin activity, and increased proteinuria. Treatment with the calpain inhibitor calpeptin prevented these effects. In cultured podocytes, pharmacologic stimulation of TRPC6-dependent calcium influx increased calpain-1 and calcineurin activity and reduced Talin-1 expression, and knockdown of TRPC6 or calpain-1 prevented these effects. CONCLUSIONS We elucidated a novel mechanism that links TRPC6 activity to calpain-1 activation and through Talin-1 loss and possibly, calcineurin activation, the podocyte injury characterizing FSGS. Therefore, calpain-1 and/or TRPC6 inhibition could be future therapeutic options to treat patients with FSGS or other podocytopathies.
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Affiliation(s)
- Kim A T Verheijden
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ramon Sonneveld
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marinka Bakker-van Bebber
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jack F M Wetzels
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tom Nijenhuis
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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20
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Takenaka T, Inoue T, Miyazaki T, Kobori H, Nishiyama A, Ishii N, Hayashi M, Suzuki H. Klotho suppresses the renin-angiotensin system in adriamycin nephropathy. Nephrol Dial Transplant 2018; 32:791-800. [PMID: 27798196 DOI: 10.1093/ndt/gfw340] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/10/2016] [Indexed: 11/13/2022] Open
Abstract
Backgrounds Klotho protein interacts with the transforming growth factor β (TGF-β) receptor and Wnt, which contribute to the progression of renal disease, inhibiting their signals. Renal and circulating klotho levels are diminished in chronic kidney disease. Methods Experiments were performed to assess whether supplementation of klotho protein could have protective effects on the kidney. Rats were injected with adriamycin (5 mg/kg) and divided into three groups: those treated with vehicle, those treated with klotho protein and those treated with klotho plus 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD). Rats without adriamycin treatment were used as a control. Results Adriamycin reduced the serum klotho concentration and renal expression of klotho and E-cadherin. Adriamycin also increased the renal expression of Wnt, TGF-β, and angiotensinogen, as well as the renal abundance of β-catenin and angiotensin II. Klotho supplementation suppressed adriamycin-induced elevations of β-catenin and angiotensin II with sustained Wnt expression. Combined treatment with klotho and TDZD reversed the klotho-induced improvements in the renal abundance of β-catenin and angiotensin II as well as the expression of TGF-β and angiotensinogen without affecting E-cadherin. Conclusions Our data indicate that Wnt is involved in the pathogenesis of adriamycin nephropathy. Furthermore, klotho supplementation inhibited Wnt signaling, ameliorating renal angiotensin II. Finally, klotho protein appears to suppress epithelial-mesenchymal transition by inhibiting TGF-β and Wnt signaling.
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Affiliation(s)
- Tsuneo Takenaka
- Department of Medicine, International University of Health and Welfare, 8-10-16 Akasaka, Minato, Tokyo 107-0052, Japan
| | - Tsutomu Inoue
- Department of Nephrology, Saitama Medical University, Iruma, Saitama, Japan
| | - Takashi Miyazaki
- Department of Nephrology, Saitama Medical University, Iruma, Saitama, Japan
| | - Hiroyuki Kobori
- Department of Medicine, International University of Health and Welfare, 8-10-16 Akasaka, Minato, Tokyo 107-0052, Japan
| | - Akira Nishiyama
- Department of Pharmacology, Kagawa University, Kida, Kagawa, Japan
| | - Naohito Ishii
- Department of Clinical Chemistry, Kitasato University, Sagamihara, Kanagawa, Japan
| | | | - Hiromichi Suzuki
- Department of Nephrology, Saitama Medical University, Iruma, Saitama, Japan
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21
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Oishi S, Suzuki N, Hasui Y, Homma T, Obana M, Nagayama T, Fujio Y. Sustained Activation of Guanylate Cyclase-A with TDT, a Natriuretic Peptide Derivative, Exhibits Cardiorenal Protection in Dahl Salt-Sensitive Hypertensive Rats. J Pharmacol Exp Ther 2017; 363:402-410. [PMID: 29021382 DOI: 10.1124/jpet.117.244459] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/02/2017] [Indexed: 11/22/2022] Open
Abstract
Heart failure often presents with prognosis-relevant impaired renal function. To investigate whether the chronic activation of guanylate cyclase-A (GC-A) protects both heart and kidney, we examined the effects of TDT, a neprilysin (NEP)-resistant natriuretic peptide (NP) derivative, on cardiac and renal dysfunction in Dahl salt-sensitive hypertensive (DS) rats. Pretreatment with NEP or NEP inhibitor did not influence GC-A activation by TDT both in vitro and in vivo, resulting in a long-acting profile of TDT compared with native human atrial NP (hANP). The repeated administration of TDT to DS rats suppressed the progress of cardiac hypertrophy, systolic/diastolic dysfunction, and proteinuria in a dose-dependent manner. Compared with vehicle and hANP, salt diet-induced podocyte injury was reduced by TDT, as analyzed by urinary podocalyxin concentration, renal expression of nephrin mRNA, and glomerular expression of desmin protein. Since glomerular TRPC6 plays detrimental roles in podocyte homeostasis, we examined the renal expression of TRPC6 in DS rats and found that salt diet upregulated the expression of TRPC6. Importantly, TRPC6 induction was significantly decreased in TDT-treated rats, compared with vehicle and hANP. Consistently, in primary-culture podocytes from DS rats, TDT inhibited ATP-induced calcium influx, similar to TRPC inhibitor SKF96365. Finally, TDT-mediated protection of podocytes was abolished by protein kinase G inhibitor KT5823. In conclusion, TDT treatment attenuated heart and kidney dysfunction, accompanied by podocyte protection through inhibition of TRPC6. Thus, long-acting NPs could be a new avenue for treatment of heart failure.
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Affiliation(s)
- Shohei Oishi
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Naoko Suzuki
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Yuri Hasui
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Tsuyoshi Homma
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Masanori Obana
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Takahiro Nagayama
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Yasushi Fujio
- Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan (S.O., M.O., Y.F.); End-Organ Disease Laboratories (S.O., Y.H., T.H.), Rare Disease & LCM Laboratories (T.N.), and Research Function (N.S.), Daiichi Sankyo Co., Ltd, Tokyo, Japan
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22
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Zhang YD, Dong QW, Li RM, Ji CY, Chu YT, Ma L, Zhang Y. [Changes in 25-hydroxyvitamin D3 level in children with Henoch-Schönlein purpura]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2017; 19:292-295. [PMID: 28302199 PMCID: PMC7390150 DOI: 10.7499/j.issn.1008-8830.2017.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/11/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To examine the changes in 25-hydroxyvitamin D3 [25-(OH)D3] level in children with Henoch-Schönlein purpura (HSP) and its clinical significance. METHODS A total of 92 HSP children were included in this study, and were divided into HSP nephritis (HSPN) group (31 cases) and HSP group (61 cases) based on the presence or absence of HSPN. Alternatively, the patients were divided into purpura alone group (22 cases), purpura with joint symptoms group (joint symptom group, 24 cases), purpura with gastrointestinal symptoms group (gastrointestinal symptom group, 20 cases), and purpura with joint and gastrointestinal symptoms (mixed group, 26 cases) based on their clinical symptoms. In addition, 42 healthy children were selected as healthy control group. The level of 25-(OH)D3 in each group was measured using enzyme-linked immunoassay. RESULTS The 25-(OH)D3 level in the HSP and HSPN groups was significantly lower than that in the healthy control group (P<0.05), and the 25-(OH)D3 level in the HSPN group was significantly lower than that in the HSP group (P<0.05). Although there was no significant difference in the 25-(OH)D3 level between the joint symptom, gastrointestinal symptom, and mixed groups (P=0.22), the 25-(OH)D3 level in the three groups was all significantly lower than that in the purpura alone group (P<0.05). CONCLUSIONS The level of 25-(OH)D3 is reduced in children with HSP, particularly those with HSPN or with joint and gastrointestinal symptoms. Therefore, the reduction in 25-(OH)D3 level may serve as a predictor of whether HSP is associated with other impairments.
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Affiliation(s)
- Yuan-Da Zhang
- Department of Pediatrics, Baoding Children's Hospital, Baoding, Hebei 071000, China.
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23
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Sonneveld R, Hoenderop JG, Isidori AM, Henique C, Dijkman HB, Berden JH, Tharaux PL, van der Vlag J, Nijenhuis T. Sildenafil Prevents Podocyte Injury via PPAR- γ-Mediated TRPC6 Inhibition. J Am Soc Nephrol 2016; 28:1491-1505. [PMID: 27895156 DOI: 10.1681/asn.2015080885] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/02/2016] [Indexed: 02/06/2023] Open
Abstract
Transient receptor potential channel C6 (TRPC6) gain-of-function mutations and increased TRPC6 expression in podocytes induce glomerular injury and proteinuria. Sildenafil reduces TRPC6 expression and activity in nonrenal cell types, although the mechanism is unknown. Peroxisome proliferator-activated receptor γ (PPAR-γ) is a downstream target of sildenafil in the cyclic guanosine monophosphate (cGMP)-activated protein kinase G (PKG) axis. PPAR-γ agonists, like pioglitazone, appear antiproteinuric. We hypothesized that sildenafil inhibits TRPC6 expression in podocytes through PPAR-γ-dependent mechanisms, thereby counteracting podocyte injury and proteinuria. Treatment with sildenafil, the cGMP derivative 8-bromoguanosine 3',5'-cyclic monophosphate sodium salt (8-Br-cGMP), or pioglitazone dose-dependently downregulated podocyte injury-induced TRPC6 expression in vitro Knockdown or application of antagonists of PKG or PPAR-γ enhanced TRPC6 expression in podocytes and counteracted effects of sildenafil and 8-Br-cGMP. We observed similar effects on TRPC6 promoter activity and TRPC6-dependent calcium influx. Chromatin immunoprecipitation showed PPAR-γ binding to the TRPC6 promoter. Sildenafil or pioglitazone treatment prevented proteinuria and the increased TRPC6 expression in rats with adriamycin-induced nephropathy and mice with hyperglycemia-induced renal injury. Rats receiving PPAR-γ antagonists displayed proteinuria and increased podocyte TRPC6 expression, as did podocyte-specific PPAR-γ knockout mice, which were more sensitive to adriamycin and not protected by sildenafil. Thus, sildenafil ameliorates podocyte injury and prevents proteinuria through cGMP- and PKG-dependent binding of PPAR-γ to the TRPC6 promoter, which inhibits TRPC6 promoter activity, expression, and activity. Because sildenafil is approved for clinical use, our results suggest that additional clinical study of its antiproteinuric effect in glomerular disease is warranted.
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Affiliation(s)
| | | | - Andrea M Isidori
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Carole Henique
- Paris Cardiovascular Centre, Institut National de la Santé et de la Recherche Médicale, Paris, France.,Sorbonne Paris Cité, Université Paris Descartes, Paris, France; and
| | - Henry B Dijkman
- Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Pierre-Louis Tharaux
- Paris Cardiovascular Centre, Institut National de la Santé et de la Recherche Médicale, Paris, France.,Sorbonne Paris Cité, Université Paris Descartes, Paris, France; and.,Service de Néphrologie, Hôpital Européen Georges Pompidou, Paris, France
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24
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Bernichtein S, Pigat N, Barry Delongchamps N, Boutillon F, Verkarre V, Camparo P, Reyes-Gomez E, Méjean A, Oudard SM, Lepicard EM, Viltard M, Souberbielle JC, Friedlander G, Capiod T, Goffin V. Vitamin D3 Prevents Calcium-Induced Progression of Early-Stage Prostate Tumors by Counteracting TRPC6 and Calcium Sensing Receptor Upregulation. Cancer Res 2016; 77:355-365. [PMID: 27879271 DOI: 10.1158/0008-5472.can-16-0687] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 10/28/2016] [Accepted: 10/31/2016] [Indexed: 01/29/2023]
Abstract
Active surveillance has emerged as an alternative to immediate treatment for men with low-risk prostate cancer. Accordingly, identification of environmental factors that facilitate progression to more aggressive stages is critical for disease prevention. Although calcium-enriched diets have been speculated to increase prostate cancer risk, their impact on early-stage tumors remains unexplored. In this study, we addressed this issue with a large interventional animal study. Mouse models of fully penetrant and slowly evolving prostate tumorigenesis showed that a high calcium diet dramatically accelerated the progression of prostate intraepithelial neoplasia, by promoting cell proliferation, micro-invasion, tissue inflammation, and expression of acknowledged prostate cancer markers. Strikingly, dietary vitamin D prevented these calcium-triggered tumorigenic effects. Expression profiling and in vitro mechanistic studies showed that stimulation of PC-3 cells with extracellular Ca2+ resulted in an increase in cell proliferation rate, store-operated calcium entry (SOCE) amplitude, cationic channel TRPC6, and calcium sensing receptor (CaSR) expression. Notably, administration of the active vitamin D metabolite calcitriol reversed all these effects. Silencing CaSR or TRPC6 expression in calcium-stimulated PC3 cells decreased cell proliferation and SOCE. Overall, our results demonstrate the protective effects of vitamin D supplementation in blocking the progression of early-stage prostate lesions induced by a calcium-rich diet. Cancer Res; 77(2); 355-65. ©2016 AACR.
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Affiliation(s)
- Sophie Bernichtein
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France
| | - Natascha Pigat
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France
| | - Nicolas Barry Delongchamps
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France.,Urology Department, Hôpital Cochin, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Florence Boutillon
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France
| | - Virginie Verkarre
- Pathology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | | | - Edouard Reyes-Gomez
- Ecole Nationale Vétérinaire d'Alfort, Laboratoire d'anatomo-cytopathologie, Inserm, IMRB U955-E10, Université Paris-Est, Maisons-Alfort, Paris, France
| | - Arnaud Méjean
- Urology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Stéphane M Oudard
- Medical Oncology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Eve M Lepicard
- Institute for European Expertise in Physiology, Paris, France
| | - Mélanie Viltard
- Institute for European Expertise in Physiology, Paris, France
| | - Jean-Claude Souberbielle
- Physiology Department, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Gérard Friedlander
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France
| | - Thierry Capiod
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France
| | - Vincent Goffin
- Inserm Unit 1151, Institut Necker Enfants Malades (INEM), Université Paris Descartes, Paris, France.
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25
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Rüster C, Franke S, Reuter S, Mrowka R, Bondeva T, Wolf G. Vitamin D3 Partly Antagonizes Advanced-Glycation Endproducts-Induced NFκB Activation in Mouse Podocytes. Nephron Clin Pract 2016; 134:105-116. [PMID: 27505422 DOI: 10.1159/000448106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 06/29/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS We have previously shown that advanced glycation-endproducts (AGEs) induced NFκB activation in differentiated mouse podocytes. This NFκB activation may contribute to the progression of renal disease and mediation of fibrosis by various mechanisms. This study was undertaken to test whether this detrimental response may be reversed by vitamin D3 or its analogue paricalcitol. METHODS Differentiated mouse podocytes were challenged with glycated bovine serum albumin (AGE-BSA), or non-glycated control BSA (in the presence or absence of various concentrations of vitamin D3 (decostriol, 1α,25-dihydroxyvitamin D3)) or its active analog paricalcitol. Quantitative mRNA expressions were measured by real-time PCR, whereas protein expressions were determined by Western blotting followed by densitometry. Cytoplasmic and nuclear protein expression of the NFκB subunit p65 (Rel A) were determined by Western blotting. Furthermore, the ratio of phosphorylated to non-phosphorylated IκB-α was measured using specific antibodies. Electrophoretic mobility shift assays and a capture ELISA assay were used to assess NFκB transactivation in vitro. In addition, NFκB transactivation was also monitored in HEK-NFκBIA reporter cells using live cell luminometry. RESULTS Podocytes expressed the receptor for vitamin D. The vitamins did not suppress receptor for AGEs (RAGE) expression; instead, they rather upregulated RAGE. Although vitamin D3 and paricalcitol partly and differentially modified some of the studied parameters, both hormones inhibited AGE-BSA-induced NFκB transactivation, presumably by various mechanisms including the upregulation of IκB-α protein, keeping NFκB sequestered in an inactive state in the cytoplasm. CONCLUSION Vitamin D3 or its analog paricalcitol partly prevented AGE-mediated NFκB activation, an important feature of diabetic nephropathy (DN). Whether this in vitro finding is of clinical relevance to prevent/treat DN requires further studies.
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Affiliation(s)
- Christiane Rüster
- Department of Internal Medicine III, University Hospital Jena, Jena, Germany
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26
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Sonneveld R, Hoenderop JG, Stavenuiter AW, Ferrantelli E, Baltissen MP, Dijkman HB, Florquin S, Rops AL, Wetzels JF, Berden JH, van der Vlag J, Nijenhuis T. 1,25-Vitamin D3 Deficiency Induces Albuminuria. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:794-804. [DOI: 10.1016/j.ajpath.2015.11.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 10/22/2015] [Accepted: 11/19/2015] [Indexed: 12/19/2022]
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27
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Abstract
PTH and Vitamin D are two major regulators of mineral metabolism. They play critical roles in the maintenance of calcium and phosphate homeostasis as well as the development and maintenance of bone health. PTH and Vitamin D form a tightly controlled feedback cycle, PTH being a major stimulator of vitamin D synthesis in the kidney while vitamin D exerts negative feedback on PTH secretion. The major function of PTH and major physiologic regulator is circulating ionized calcium. The effects of PTH on gut, kidney, and bone serve to maintain serum calcium within a tight range. PTH has a reciprocal effect on phosphate metabolism. In contrast, vitamin D has a stimulatory effect on both calcium and phosphate homeostasis, playing a key role in providing adequate mineral for normal bone formation. Both hormones act in concert with the more recently discovered FGF23 and klotho, hormones involved predominantly in phosphate metabolism, which also participate in this closely knit feedback circuit. Of great interest are recent studies demonstrating effects of both PTH and vitamin D on the cardiovascular system. Hyperparathyroidism and vitamin D deficiency have been implicated in a variety of cardiovascular disorders including hypertension, atherosclerosis, vascular calcification, and kidney failure. Both hormones have direct effects on the endothelium, heart, and other vascular structures. How these effects of PTH and vitamin D interface with the regulation of bone formation are the subject of intense investigation.
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Affiliation(s)
- Syed Jalal Khundmiri
- Department of Medicine, University of Louisville, Louisville, Kentucky, USA
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA
| | - Rebecca D. Murray
- Department of Medicine, University of Louisville, Louisville, Kentucky, USA
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA
| | - Eleanor Lederer
- Department of Medicine, University of Louisville, Louisville, Kentucky, USA
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA
- Robley Rex VA Medical Center, University of Louisville, Louisville, Kentucky, USA
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28
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Bouron A, Chauvet S, Dryer S, Rosado JA. Second Messenger-Operated Calcium Entry Through TRPC6. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 898:201-49. [PMID: 27161231 DOI: 10.1007/978-3-319-26974-0_10] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Canonical transient receptor potential 6 (TRPC6) proteins assemble into heteromultimeric structures forming non-selective cation channels. In addition, many TRPC6-interacting proteins have been identified like some enzymes, channels, pumps, cytoskeleton-associated proteins, immunophilins, or cholesterol-binding proteins, indicating that TRPC6 are engaged into macromolecular complexes. Depending on the cell type and the experimental conditions used, TRPC6 activity has been reported to be controlled by diverse modalities. For instance, the second messenger diacylglycerol, store-depletion, the plant extract hyperforin or H2O2 have all been shown to trigger the opening of TRPC6 channels. A well-characterized consequence of TRPC6 activation is the elevation of the cytosolic concentration of Ca(2+). This latter response can reflect the entry of Ca(2+) through open TRPC6 channels but it can also be due to the Na(+)/Ca(2+) exchanger (operating in its reverse mode) or voltage-gated Ca(2+) channels (recruited in response to a TRPC6-mediated depolarization). Although TRPC6 controls a diverse array of biological functions in many tissues and cell types, its pathophysiological functions are far from being fully understood. This chapter covers some key features of TRPC6, with a special emphasis on their biological significance in kidney and blood cells.
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Affiliation(s)
- Alexandre Bouron
- Université Grenoble Alpes, 38000, Grenoble, France. .,CNRS, iRTSV-LCBM, 38000, Grenoble, France.
| | - Sylvain Chauvet
- Université Grenoble Alpes, 38000, Grenoble, France.,CNRS, iRTSV-LCBM, 38000, Grenoble, France
| | - Stuart Dryer
- University of Houston, Houston, TX, USA.,Baylor College of Medicine, Houston, TX, USA
| | - Juan A Rosado
- Departamento de Fisiología, University of Extremadura, Cáceres, Spain
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29
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Bhatti AB, Usman M. Drug Targets for Oxidative Podocyte Injury in Diabetic Nephropathy. Cureus 2015; 7:e393. [PMID: 26798569 PMCID: PMC4699926 DOI: 10.7759/cureus.393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 11/30/2015] [Indexed: 12/19/2022] Open
Abstract
Diabetic nephropathy (DN) is one the most prevalent chronic complications of diabetes mellitus that affects as much as one-third of diabetic patients irrespective of the type of diabetes. Hyperglycemia is the key trigger for DN that initiates a number of microscopic and ultramicroscopic changes in kidney architecture. Microscopic changes include thickening of the glomerular basement membrane (GBM), tubular basement membrane (TBM), mesangial proliferation, arteriosclerosis, and glomerulotubular junction abnormalities (GTJA). Among the ultramicroscopic changes, effacement of podocytes and decrease in their density seem to be the centerpiece of DN pathogenesis. These changes in kidney architecture then produce functional deficits, such as microalbuminuria and decreased glomerular filtration rate (GFR). Among several mechanisms involved in inflicting damage to podocytes, injuries sustained by increased oxidative stress turns out to be the most important mechanism. Different variables that are included in increased production of reactive oxygen species (ROS) include a hyperglycemia-induced reduction in glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation via hyperglycemia, advanced glycation end products (AGEs), protein kinase C (PKC), and renin-angiotensin-aldosterone system (RAAS). Unfortunately, control of podocyte injury hasn't received much attention as a treatment approach for DN. Therefore, this review article is mainly concerned with the exploration of various treatment options that might help in decreasing the podocyte injury, mainly by reducing the level of NADPH oxidase-mediated generation of ROS. This article concludes with a view that certain NADPH oxidase inhibitors, RAAS inhibitors, statins, antidiabetic drugs, and antioxidant vitamins might be useful in decreasing podocyte injury and resultant structural and functional kidney impairments in DN.
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Affiliation(s)
- Adnan Bashir Bhatti
- Department of Medicine, Capital Development Authority Hospital, Islamabad, Pakistan
| | - Muhammad Usman
- Department of Medicine, Jinnah Hospital Lahore (JHL)/Allama Iqbal Medical College (AIMC), Lahore, Pakistan
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30
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Garsen M, Sonneveld R, Rops ALWMM, Huntink S, van Kuppevelt TH, Rabelink TJ, Hoenderop JGJ, Berden JHM, Nijenhuis T, van der Vlag J. Vitamin D attenuates proteinuria by inhibition of heparanase expression in the podocyte. J Pathol 2015. [DOI: 10.1002/path.4593] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Marjolein Garsen
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Ramon Sonneveld
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Angelique LWMM Rops
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Suzanne Huntink
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Toin H van Kuppevelt
- Department of Biochemistry; Radboud University Medical Center; Nijmegen The Netherlands
| | - Ton J Rabelink
- Department of Nephrology, Einthoven Laboratory for Vascular Medicine; Leiden University Medical Center; Leiden The Netherlands
| | - Joost GJ Hoenderop
- Department of Physiology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Jo HM Berden
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Tom Nijenhuis
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
| | - Johan van der Vlag
- Department of Nephrology; Radboud University Medical Center; Nijmegen The Netherlands
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31
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Wnt/β-catenin signalling and podocyte dysfunction in proteinuric kidney disease. Nat Rev Nephrol 2015; 11:535-45. [PMID: 26055352 DOI: 10.1038/nrneph.2015.88] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Podocytes are unique, highly specialized, terminally differentiated cells that are integral components of the kidney glomerular filtration barrier. Podocytes are vulnerable to a variety of injuries and in response they undergo a series of changes ranging from hypertrophy, autophagy, dedifferentiation, mesenchymal transition and detachment to apoptosis, depending on the nature and extent of the insult. Emerging evidence indicates that Wnt/β-catenin signalling has a central role in mediating podocyte dysfunction and proteinuria. Wnts are induced and β-catenin is activated in podocytes in various proteinuric kidney diseases. Genetic or pharmacologic activation of β-catenin is sufficient to impair podocyte integrity and causes proteinuria in healthy mice, whereas podocyte-specific ablation of β-catenin protects against proteinuria after kidney injury. Mechanistically, Wnt/β-catenin controls the expression of several key mediators implicated in podocytopathies, including Snail1, the renin-angiotensin system and matrix metalloproteinase 7. Wnt/β-catenin also negatively regulates Wilms tumour protein, a crucial transcription factor that safeguards podocyte integrity. Targeted inhibition of Wnt/β-catenin signalling preserves podocyte integrity and ameliorates proteinuria in animal models. This Review highlights advances in our understanding of the pathomechanisms of Wnt/β-catenin signalling in mediating podocyte injury, and describes the therapeutic potential of targeting this pathway for the treatment of proteinuric kidney disease.
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32
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Zhang X, Song Z, Guo Y, Zhou M. The novel role of TRPC6 in vitamin D ameliorating podocyte injury in STZ-induced diabetic rats. Mol Cell Biochem 2014; 399:155-65. [DOI: 10.1007/s11010-014-2242-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/01/2014] [Indexed: 01/19/2023]
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33
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Song Z, Guo Y, Zhou M, Zhang X. The PI3K/p-Akt signaling pathway participates in calcitriol ameliorating podocyte injury in DN rats. Metabolism 2014; 63:1324-33. [PMID: 25044177 DOI: 10.1016/j.metabol.2014.06.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 06/08/2014] [Accepted: 06/17/2014] [Indexed: 01/19/2023]
Abstract
OBJECTIVES The present study aimed to investigate the relationship between PI3K/p-Akt signaling pathway and podocyte impairment in DN rats as well as the protective effect of calcitriol. METHODS SD rats were randomly divided into four groups: normal control (NC), normal treated with calcitriol (NC+VD), diabetic nephropathy (DN) and DN treated with calcitriol (DN+VD); all VD rats were treated with 0.1 μg/kg/d calcitriol by gavage. DN model rats were established by intraperitoneal injections of streptozotocin (STZ). Rats were sacrificed after 18 weeks of treatments. RESULTS In the present study, increased albuminuria was observed as early as 3 weeks of diabetes and continued to increase more than six-fold throughout the length of the study (18 weeks). Expectedly, animals receiving the treatment with calcitriol was protected from this increase, lower about one third. Meanwhile, the expression of podocyte specific markers, including nephrin and podocin, together with PI3K/p-Akt was significantly decreased in DN rats, whereas calcitriol reversed these above changes accompanied by elevated the expression levels of VDR. Additionally, a positive correlation was observed between the expression levels of nephrin and VDR (r = 0.776, P < 0.05). Likewise, the expression of nephrin was positively correlated with both PI3K-p85 and p-Akt (r = 0.736, P < 0.05; r = 0.855, P < 0.05, respectively). CONCLUSION PI3K/p-Akt signaling pathway participates in calcitriol ameliorating podocyte injury in DN rats. The manipulation of calcitriol might act as a promising therapeutic intervention for diabetic nephropathy.
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Affiliation(s)
- Zhixia Song
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu 210009 China
| | - Yinfeng Guo
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu 210009 China
| | - Min Zhou
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu 210009 China
| | - Xiaoliang Zhang
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu 210009 China.
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Hofstra JM, Coenen MJH, Schijvenaars MMVAP, Berden JHM, van der Vlag J, Hoefsloot LH, Knoers NVAM, Wetzels JFM, Nijenhuis T. TRPC6 single nucleotide polymorphisms and progression of idiopathic membranous nephropathy. PLoS One 2014; 9:e102065. [PMID: 25019165 PMCID: PMC4096511 DOI: 10.1371/journal.pone.0102065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 06/13/2014] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Activating mutations in the Transient Receptor Potential channel C6 (TRPC6) cause autosomal dominant focal segmental glomerular sclerosis (FSGS). TRPC6 expression is upregulated in renal biopsies of patients with idiopathic membranous glomerulopathy (iMN) and animal models thereof. In iMN, disease progression is characterized by glomerulosclerosis. In addition, a context-dependent TRPC6 overexpression was recently suggested in complement-mediated podocyte injury in e.g. iMN. Hence, we hypothesized that genetic variants in TRPC6 might affect susceptibility to development or progression of iMN. METHODS & RESULTS Genomic DNA was isolated from blood samples of 101 iMN patients and 292 controls. By direct sequencing of the entire TRPC6 gene, 13 single nucleotide polymorphisms (SNPs) were identified in the iMN cohort, two of which were causing an amino acid substitution (rs3802829; Pro15Ser and rs36111323, Ala404Val). No statistically significant differences in genotypes or allele frequencies between patients and controls were observed. Clinical outcome in patients was determined (remission n = 26, renal failure n = 46, persistent proteinuria n = 29, follow-up median 80 months {range 51-166}). The 13 identified SNPs showed no association with remission or renal failure. There were no differences in genotypes or allele frequencies between patients in remission and progressors. CONCLUSIONS Our data suggest that TRPC6 polymorphisms do not affect susceptibility to iMN, or clinical outcome in iMN.
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Affiliation(s)
- Julia M. Hofstra
- Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands
| | - Marieke J. H. Coenen
- Department of Human Genetics, Radboud university medical center, Nijmegen, the Netherlands
| | | | - Jo H. M. Berden
- Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands
| | - Lies H. Hoefsloot
- Department of Human Genetics, Radboud university medical center, Nijmegen, the Netherlands
| | - Nine V. A. M. Knoers
- Department of Human Genetics, Radboud university medical center, Nijmegen, the Netherlands
| | - Jack F. M. Wetzels
- Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands
| | - Tom Nijenhuis
- Department of Nephrology, Radboud university medical center, Nijmegen, the Netherlands
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Sonneveld R, van der Vlag J, Baltissen MPA, Verkaart SAJ, Wetzels JFM, Berden JHM, Hoenderop JGJ, Nijenhuis T. Glucose specifically regulates TRPC6 expression in the podocyte in an AngII-dependent manner. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1715-26. [PMID: 24731445 DOI: 10.1016/j.ajpath.2014.02.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/20/2014] [Accepted: 02/18/2014] [Indexed: 12/16/2022]
Abstract
Slit diaphragm and podocyte damage is crucial in the pathogenesis of proteinuria in diabetic nephropathy (DNP). Gain-of-function mutations in TRPC6, a slit diaphragm-associated ion channel, cause glomerulosclerosis; TRPC6 expression is increased in acquired glomerular disease. Hyperglycemia and high intrarenal angiotensin II (AngII) levels could contribute to podocyte injury in DNP. We determined whether glucose regulates TRPC6 expression and TRPC6-mediated Ca(2+) influx into the podocyte and whether these effects are AngII dependent. High glucose levels increased TRPC6 mRNA and protein expression in cultured podocytes; however, TRPC1 and TRPC5 mRNA expression was unaltered. AngII and inducing podocyte injury also specifically increased TRPC6 expression. Angiotensin receptor blockade and inhibition of local AngII production through angiotensin-converting enzyme inhibition prevented glucose-mediated increased TRPC6 expression. In addition, high glucose concentration pretreatment enhanced Ca(2+) influx in podocytes, which was prevented by concomitant angiotensin receptor blockade application and TRPC6 knockdown. Studies with a TRPC6 luciferase promoter construct demonstrated a glucose concentration-dependent effect on TRPC6 promoter activity. In vivo, podocyte TRPC6 protein expression was increased in proteinuric streptozotocin-induced diabetic rats. These data suggest that glucose can activate a local renin-angiotensin system in the podocyte, leading to increased TRPC6 expression, which enhances TRPC6-mediated Ca(2+) influx. Regulation of TRPC6 expression could be an important factor in podocyte injury due to chronic hyperglycemia and the antiproteinuric effect of angiotensin receptor blockade or angiotensin-converting enzyme inhibition in DNP.
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Affiliation(s)
- Ramon Sonneveld
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marijke P A Baltissen
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sjoerd A J Verkaart
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jack F M Wetzels
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jo H M Berden
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tom Nijenhuis
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands.
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Sethna CB, Gipson DS. Treatment of FSGS in Children. Adv Chronic Kidney Dis 2014; 21:194-9. [PMID: 24602468 DOI: 10.1053/j.ackd.2014.01.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 01/16/2014] [Indexed: 01/17/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a pathologic condition that represents many disease entities. The goals of therapy are to cure the disease. When this is not possible, the secondary goals are to reduce proteinuria to avoid the complications of nephrotic syndrome and to delay progression of kidney disease. Proteinuria remission is one of the most important independent predictors of kidney survival. Children with FSGS who do not achieve partial or complete remission have a 50% risk of progression to ESRD within 5 years whereas those who enter complete remission have a 5-year kidney survival rate of 90%. Treatment of idiopathic FSGS commonly involves immune-based and nonimmunologic therapy options. This manuscript will review the current state of FSGS therapy for children.
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Axelsson J, Rippe A, Sverrisson K, Rippe B. Scavengers of reactive oxygen species, paracalcitol, RhoA, and Rac-1 inhibitors and tacrolimus inhibit angiotensin II-induced actions on glomerular permeability. Am J Physiol Renal Physiol 2013; 305:F237-43. [DOI: 10.1152/ajprenal.00154.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Systemic infusions of ANG II rapidly induce large, dynamic increases in the permeability of the glomerular filtration barrier (GFB) in rats. After binding to its receptor(s), ANG II generates reactive oxygen species (ROS) and produces Ca2+ influx into cells, leading to activation of a plethora of signaling cascades, including, e.g., calcineurin and small GTPases, such as Rac-1 and RhoA. In the present study we sought to interact with some of these cascades to test potential novel antiproteinuric agents. In anesthetized Wistar rats, the left urether was cannulated for urine collection, and blood access was achieved. Rats were infused with ANG II (16 ng·kg−1·min−1) alone, or together with the ROS scavengers tempol or dimethylthiourea (DMTU) or the D-vitamin analog paracalcitol, the RhoA-kinase inhibitor Y-27632, the Rac-1 inhibitor NSC-23766, or the calcineurin inhibitor tacrolimus. FITC-Ficoll-70/400 (mol.radius 10–80 Å) and 51Cr-EDTA were infused throughout the experiment. Plasma and urine samples were taken during baseline and at 5 and 15 min after the start of the infusions and analyzed by high-performance size-exclusion chromatography for determination of glomerular sieving coefficients (θ) for Ficoll10–80Å. ANG II infusion into rats caused marked increases in glomerular permeability to large Ficoll molecules (Ficoll50–80Å), which were abrogated by the ROS scavenger tempol and partly by DMTU. Paracalcitol, RhoA, and Rac-1 inhibition, and, to some extent tacrolimus, but not prostacyclin, could also inhibit the glomerular permeability actions of ANG II. Our data suggest that cellular ROS generation and active Ca2+ signaling are involved in ANG II-induced increases in glomerular permeability.
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Affiliation(s)
| | - Anna Rippe
- Department of Nephrology, Lund University, Lund, Sweden
| | | | - Bengt Rippe
- Department of Nephrology, Lund University, Lund, Sweden
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