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Pang G, Ye L, Jiang Y, Wu Y, Zhang R, Yang H, Yang Y. Unveiling the bidirectional role of MMP9: A key player in kidney injury. Cell Signal 2024; 122:111312. [PMID: 39074714 DOI: 10.1016/j.cellsig.2024.111312] [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: 05/15/2024] [Revised: 07/04/2024] [Accepted: 07/22/2024] [Indexed: 07/31/2024]
Abstract
Matrix metalloproteinases (MMPs) are a group of zinc-dependent proteolytic metalloenzymes that are involved in numerous pathological conditions, including nephropathy. MMP9, a member of the MMPs family, is categorized as a constituent of the gelatinase B subgroup, and its involvement in extracellular matrix (ECM) remodeling and renal fibrosis highlights its importance in the development and progression of renal diseases. The exact role of MMP9 in the development of kidney diseases is still controversial. This study investigated the dual role of MMP9 in kidney injury, discussing its implications in the pathogenesis of kidney diseases and investigating the design and mechanism of MMP9 inhibitors based on previous studies. This study provides an effective basis for the development of novel and selective MMP9 inhibitors for treating renal diseases.
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Affiliation(s)
- Guiying Pang
- Anhui University of Traditional Chinese Medicine, Hefei 230000, People's Republic of China; Institute of Innovative Medicine, Biocytogen Pharmaceuticals (Beijing) Co, Ltd., Beijing 102609, People's Republic of China; Joint Graduate School, Yangtze Delta Drug Advanced Research Institute, Nantong 226133, People's Republic of China
| | - Ling Ye
- Anhui University of Traditional Chinese Medicine, Hefei 230000, People's Republic of China; Department of Pharmacology, Biocytogen Pharmaceuticals (Beijing) Co, Ltd, Beijing 102609, People's Republic of China; Joint Graduate School, Yangtze Delta Drug Advanced Research Institute, Nantong 226133, People's Republic of China
| | - Yinxiao Jiang
- Anhui University of Traditional Chinese Medicine, Hefei 230000, People's Republic of China; Joint Graduate School, Yangtze Delta Drug Advanced Research Institute, Nantong 226133, People's Republic of China
| | - Yilin Wu
- Anhui University of Traditional Chinese Medicine, Hefei 230000, People's Republic of China; Institute of Innovative Medicine, Biocytogen Pharmaceuticals (Beijing) Co, Ltd., Beijing 102609, People's Republic of China; Joint Graduate School, Yangtze Delta Drug Advanced Research Institute, Nantong 226133, People's Republic of China
| | - Rufeng Zhang
- Institute of Innovative Medicine, Biocytogen Pharmaceuticals (Beijing) Co, Ltd., Beijing 102609, People's Republic of China; Department of Pharmacology, Biocytogen Pharmaceuticals (Beijing) Co, Ltd, Beijing 102609, People's Republic of China
| | - Hongxu Yang
- Institute of Innovative Medicine, Biocytogen Pharmaceuticals (Beijing) Co, Ltd., Beijing 102609, People's Republic of China.
| | - Yi Yang
- Institute of Innovative Medicine, Biocytogen Pharmaceuticals (Beijing) Co, Ltd., Beijing 102609, People's Republic of China; Joint Graduate School, Yangtze Delta Drug Advanced Research Institute, Nantong 226133, People's Republic of China.
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2
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Rodrigues MC, Oliveira LBF, Vieira MAR, Caruso-Neves C, Peruchetti DB. Receptor-mediated endocytosis in kidney cells during physiological and pathological conditions. CURRENT TOPICS IN MEMBRANES 2024; 93:1-25. [PMID: 39181576 DOI: 10.1016/bs.ctm.2024.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Mammalian cell membranes are very dynamic where they respond to several environmental stimuli by rearranging the membrane composition by basic biological processes, including endocytosis. In this context, receptor-mediated endocytosis, either clathrin-dependent or caveolae-dependent, is involved in different physiological and pathological conditions. In the last years, an important amount of evidence has been reported that kidney function involves the modulation of different types of endocytosis, including renal protein handling. In addition, the dysfunction of the endocytic machinery is involved with the development of proteinuria as well as glomerular and tubular injuries observed in kidney diseases associated with hypertension, diabetes, and others. In this present review, we will discuss the mechanisms underlying the receptor-mediated endocytosis in different glomerular cells and proximal tubule epithelial cells as well as their modulation by different factors during physiological and pathological conditions. These findings could help to expand the current understanding regarding renal protein handling as well as identify possible new therapeutic targets to halt the progression of kidney disease.
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Affiliation(s)
- Mariana C Rodrigues
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Laura B F Oliveira
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Maria Aparecida R Vieira
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Celso Caruso-Neves
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Rio de Janeiro Innovation Network in Nanosystems for Health-NanoSAUDE/FAPERJ, Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa, INCT-Regenera, Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCTI, Rio de Janeiro, RJ, Brazil
| | - Diogo B Peruchetti
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; Instituto Nacional de Ciência e Tecnologia em Nanobiofarmacêutica, INCT-NANOBiofar, Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCTI, Belo Horizonte, MG, Brazil.
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3
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Faria J, Gerritsen KGF, Nguyen TQ, Mihaila SM, Masereeuw R. Diabetic proximal tubulopathy: Can we mimic the disease for in vitro screening of SGLT inhibitors? Eur J Pharmacol 2021; 908:174378. [PMID: 34303664 DOI: 10.1016/j.ejphar.2021.174378] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 11/27/2022]
Abstract
Diabetic kidney disease (DKD) is the foremost cause of renal failure. While the glomeruli are severely affected in the course of the disease, the main determinant for disease progression is the tubulointerstitial compartment. DKD does not develop in the absence of hyperglycemia. Since the proximal tubule is the major player in glucose reabsorption, it has been widely studied as a therapeutic target for the development of new therapies. Currently, there are several proximal tubule cell lines available, being the human kidney-2 (HK-2) and human kidney clone-8 (HKC-8) cell lines the ones widely used for studying mechanisms of DKD. Studies in these models have pushed forward the understanding on how DKD unravels, however, these cell culture models possess limitations that hamper research, including lack of transporters and dedifferentiation. The sodium-glucose cotransporters (SGLT) are identified as key players in glucose reabsorption and pharmacological inhibitors have shown to be beneficial for the long-term clinical outcome in DKD. However, their mechanism of action has, as of yet, not been fully elucidated. To comprehend the protective effects of SGLT inhibitors, it is essential to understand the complete functional, structural, and molecular features of the disease, which until now have been difficult to recapitulate. This review addresses the molecular events of diabetic proximal tubulopathy. In addition, we evaluate the protective role of SGLT inhibitors in cardiovascular and renal outcomes, and provide an overview of various in vitro models mimicking diabetic proximal tubulopathy used so far. Finally, new insights on advanced in vitro systems to surpass past limitations are postulated.
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Affiliation(s)
- João Faria
- Div. Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, the Netherlands
| | - Karin G F Gerritsen
- Dept. Nephrology and Hypertension, University Medical Center Utrecht, the Netherlands
| | - Tri Q Nguyen
- Dept. Pathology, University Medical Center Utrecht, the Netherlands
| | - Silvia M Mihaila
- Div. Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, the Netherlands; Dept. Nephrology and Hypertension, University Medical Center Utrecht, the Netherlands
| | - Rosalinde Masereeuw
- Div. Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, the Netherlands.
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4
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High glucose-induced Smad3 linker phosphorylation and CCN2 expression are inhibited by dapagliflozin in a diabetic tubule epithelial cell model. Biosci Rep 2021; 41:228674. [PMID: 34003249 PMCID: PMC8220447 DOI: 10.1042/bsr20203947] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND In the kidney glucose is freely filtered by the glomerulus and, mainly, reabsorbed by sodium glucose cotransporter 2 (SGLT2) expressed in the early proximal tubule. Human proximal tubule epithelial cells (PTECs) undergo pathological and fibrotic changes seen in diabetic kidney disease (DKD) in response to elevated glucose. We developed a specific in vitro model of DKD using primary human PTECs with exposure to high D-glucose and TGF-β1 and propose a role for SGLT2 inhibition in regulating fibrosis. METHODS Western blotting was performed to detect cellular and secreted proteins as well as phosphorylated intracellular signalling proteins. qPCR was used to detect CCN2 RNA. Gamma glutamyl transferase (GT) activity staining was performed to confirm PTEC phenotype. SGLT2 and ERK inhibition on high D-glucose, 25 mM, and TGF-β1, 0.75 ng/ml, treated cells was explored using dapagliflozin and U0126, respectively. RESULTS Only the combination of high D-glucose and TGF-β1 treatment significantly up-regulated CCN2 RNA and protein expression. This increase was significantly ameliorated by dapagliflozin. High D-glucose treatment raised phospho ERK which was also inhibited by dapagliflozin. TGF-β1 increased cellular phospho SSXS Smad3 serine 423 and 425, with and without high D-glucose. Glucose alone had no effect. Smad3 serine 204 phosphorylation was significantly raised by a combination of high D-glucose+TGF-β1; this rise was significantly reduced by both SGLT2 and MEK inhibition. CONCLUSIONS We show that high D-glucose and TGF-β1 are both required for CCN2 expression. This treatment also caused Smad3 linker region phosphorylation. Both outcomes were inhibited by dapagliflozin. We have identified a novel SGLT2 -ERK mediated promotion of TGF-β1/Smad3 signalling inducing a pro-fibrotic growth factor secretion. Our data evince support for substantial renoprotective benefits of SGLT2 inhibition in the diabetic kidney.
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A high salt diet induces tubular damage associated with a pro-inflammatory and pro-fibrotic response in a hypertension-independent manner. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165907. [DOI: 10.1016/j.bbadis.2020.165907] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 12/14/2022]
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Peruchetti DB, Silva-Filho JL, Silva-Aguiar RP, Teixeira DE, Takiya CM, Souza MC, Henriques MDG, Pinheiro AAS, Caruso-Neves C. IL-4 Receptor α Chain Protects the Kidney Against Tubule-Interstitial Injury Induced by Albumin Overload. Front Physiol 2020; 11:172. [PMID: 32174845 PMCID: PMC7056741 DOI: 10.3389/fphys.2020.00172] [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: 10/03/2019] [Accepted: 02/13/2020] [Indexed: 12/11/2022] Open
Abstract
Increasing evidence has highlighted the role of tubule-interstitial injury (TII) as a vital step in the pathogenesis of acute kidney injury (AKI). Incomplete repair of TII during AKI could lead to the development of chronic kidney disease. Changes in albumin endocytosis in proximal tubule epithelial cells (PTECs) is linked to the development of TII. In this context, interleukin (IL)-4 has been shown to be an important factor in modulating recovery of TII. We have studied the possible role of IL-4 in TII induced by albumin overload. A subclinical AKI model characterized by albumin overload in the proximal tubule was used, without changing glomerular function. Four groups were generated: (1) CONT, wild-type mice treated with saline; (2) BSA, wild-type mice treated with 10 g/kg/day bovine serum albumin (BSA); (3) KO, IL4Rα–/– mice treated with saline; and (4) KO + BSA, IL4Rα–/– mice treated with BSA. As reported previously, mice in the BSA group developed TII without changes in glomerular function. The following parameters were increased in the KO + BSA group compared with the BSA group: (1) tubular injury score; (2) urinary γ-glutamyltransferase; (3) CD4+ T cells, dendritic cells, macrophages, and neutrophils are associated with increases in renal IL-6, IL-17, and transforming growth factor β. A decrease in M2-subtype macrophages associated with a decrease in collagen deposition was observed. Using LLC-PK1 cells, a model of PTECs, we observed that (1) these cells express IL-4 receptor α chain associated with activation of the JAK3/STAT6 pathway; (2) IL-4 alone did not change albumin endocytosis but did reverse the inhibitory effect of higher albumin concentration. This effect was abolished by JAK3 inhibitor. A further increase in urinary protein and creatinine levels was observed in the KO + BSA group compared with the BSA group, but not compared with the CONT group. These observations indicate that IL-4 has a protective role in the development of TII induced by albumin overload that is correlated with modulation of the pro-inflammatory response. We propose that megalin-mediated albumin endocytosis in PTECs could work as a sensor, transducer, and target during the genesis of TII.
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Affiliation(s)
- Diogo B Peruchetti
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - João Luiz Silva-Filho
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rodrigo P Silva-Aguiar
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Douglas E Teixeira
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Christina M Takiya
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mariana C Souza
- Instituto de Tecnologia em Fármacos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Ana Acacia S Pinheiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Rio de Janeiro Innovation Network in Nanosystems for Health - NanoSAUìDE/FAPERJ, Rio de Janeiro, Brazil
| | - Celso Caruso-Neves
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Rio de Janeiro Innovation Network in Nanosystems for Health - NanoSAUìDE/FAPERJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa, INCT-Regenera, Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCTIC, Rio de Janeiro, Brazil
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7
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Li Z, Liu Y, Zhang H, Pu Z, Wu X, Li P. Effect of fosinopril on the renal cortex protein expression profile of Otsuka Long-Evans Tokushima Fatty rats. Exp Ther Med 2019; 19:172-182. [PMID: 31853288 PMCID: PMC6909786 DOI: 10.3892/etm.2019.8188] [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] [Received: 11/29/2018] [Accepted: 08/23/2019] [Indexed: 12/21/2022] Open
Abstract
Angiotensin-converting enzyme inhibitors (ACEIs) can reduce urinary protein excretion and postpone the deterioration of renal function. However, the mechanisms of renal protection are not yet fully understood. To investigate the mechanisms of ACEIs in the treatment of diabetic nephropathy (DN), the present study determined the effects of the ACEI fosinopril (FP) on the profiling of renal cortex protein expression in Otsuka Long-Evans Tokushima Fatty (OLETF) rats using Long-Evans Tokushima Otsuka (LETO) rats as controls. Urinary protein levels at 24 h were examined using the Broadford method. PAS staining was performed to observe renal histopathological changes. The kidney cortices of OLETF, FP-treated OLETF and LETO rats were examined using soluble and insoluble high-resolution subproteomic analysis methodology at age of 36 and 56 weeks. Differentiated proteins were further confirmed using western blotting analysis. The results demonstrated that FP significantly decreased the glomerulosclerosis index and reduced the 24 h urinary protein excretion of OLETF rats. Additionally, 17 proteins significantly changed following FP-treatment. Amongst these proteins, the abundances of the stress-response protein heat shock protein family A member 9 and the antioxidant glutathione peroxidase 3 were particularly increased. These results indicated that FP ameliorated diabetic renal injuries by inhibiting oxidative stress. In conclusion, the differentially expressed proteins may improve our understanding of the mechanism of ACEIs in the OLETF rats.
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Affiliation(s)
- Zhiguo Li
- Department of Medical Research Center, International Science and Technology Cooperation Base of Geriatric Medicine, North China University of Science and Technology, Tangshan, Hebei 063210, P.R. China
| | - Yeqiang Liu
- Department of Endocrinology, Kailuan General Hospital, Tangshan, Hebei 063000, P.R. China
| | - Haojun Zhang
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, P.R. China
| | - Zhijie Pu
- Graduate School, North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China
| | - Xuejing Wu
- Graduate School, North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China
| | - Ping Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, P.R. China
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8
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Cabezas F, Farfán P, Marzolo MP. Participation of the SMAD2/3 signalling pathway in the down regulation of megalin/LRP2 by transforming growth factor beta (TGF-ß1). PLoS One 2019; 14:e0213127. [PMID: 31120873 PMCID: PMC6532859 DOI: 10.1371/journal.pone.0213127] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/08/2019] [Indexed: 12/19/2022] Open
Abstract
Megalin/LRP2 is a receptor that plays important roles in the physiology of several organs, such as kidney, lung, intestine, and gallbladder and also in the physiology of the nervous system. Megalin expression is reduced in diseases associated with fibrosis, including diabetic nephropathy, hepatic fibrosis and cholelithiasis, as well as in some breast and prostate cancers. One of the hallmarks of these conditions is the presence of the cytokine transforming growth factor beta (TGF-ß). Although TGF-ß has been implicated in the reduction of megalin levels, the molecular mechanism underlying this regulation is not well understood. Here, we show that treatment of two epithelial cell lines (from kidney and gallbladder) with TGF-ß1 is associated with decreased megalin mRNA and protein levels, and that these effects are reversed by inhibiting the TGF-ß1 type I receptor (TGF-ßRI). Based on in silico analyses, the two SMAD-binding elements (SBEs) in the megalin promoter are located at positions -57 and -605. Site-directed mutagenesis of the SBEs and chromatin immunoprecipitation (ChIP) experiments revealed that SMAD2/3 transcription factors interact with SBEs. Both the presence of SMAD2/3 and intact SBEs were associated with repression of the megalin promoter, in the absence as well in the presence of TGF-ß1. Also, reduced megalin expression and promoter activation triggered by high concentration of albumin are dependent on the expression of SMAD2/3. Interestingly, the histone deacetylase inhibitor Trichostatin A (TSA), which induces megalin expression, reduced the effects of TGF-ß1 on megalin mRNA levels. These data show the significance of TGF-ß and the SMAD2/3 signalling pathway in the regulation of megalin and explain the decreased megalin levels observed under conditions in which TGF-ß is upregulated, including fibrosis-associated diseases and cancer.
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Affiliation(s)
- Felipe Cabezas
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pamela Farfán
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
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9
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Zhao X, Chen X, Chima A, Zhang Y, George J, Cobbs A, Emmett N. Albumin induces CD44 expression in glomerular parietal epithelial cells by activating extracellular signal-regulated kinase 1/2 pathway. J Cell Physiol 2019; 234:7224-7235. [PMID: 30362534 PMCID: PMC6344259 DOI: 10.1002/jcp.27477] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/04/2018] [Indexed: 01/21/2023]
Abstract
De novo expression of CD44 in glomerular parietal epithelial cells (PECs) leads to a prosclerotic and migratory PEC phenotype in glomerulosclerosis. However, the regulatory mechanisms underlying CD44 expression by activated PECs remain largely unknown. This study was performed to examine the mediators responsible for CD44 induction in glomerular PECs in association with diabetes. CD44 expression and localization were evaluated in the glomeruli of Zucker diabetic rat kidneys and primary cultured PECs upon albumin stimulation. Real-time polymerase chain reaction confirmed an albuminuria-associated upregulation of the CD44 gene in the glomeruli of diabetic rats. Immunostaining analysis of diabetic kidneys further revealed an increase in CD44 in hypertrophic PECs, which often contain albumin-positive vesicles. Losartan treatment significantly attenuated albuminuria and lowered CD44 protein levels in the diabetic kidneys. In primary cultured rat PECs, rat serum albumin (0.25-1 mg/ml) caused a dose-dependent upregulation of CD44, claudin-1, and megalin protein expression, which was accompanied by an activation of extracellular signal-regulated kinase1/2 (ERK1/2) signaling. Albumin-induced CD44 and claudin-1 expression were greatly suppressed in the presence of the ERK1/2 inhibitor, U0126. In addition, knockdown of megalin by small interfering RNA interference in PECs resulted in a significant reduction of albumin-induced CD44 and claudin-1 proteins. Taken together, our results demonstrate that albumin induces CD44 expression by PECs via the activation of the ERK signaling pathway, which is partially mediated by endocytic receptor megalin.
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Affiliation(s)
- Xueying Zhao
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
| | - Xiaoming Chen
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
| | - Ashmeer Chima
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
| | - Yuanyuan Zhang
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
| | - Jasmine George
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
| | - Alyssa Cobbs
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
| | - Nerimiah Emmett
- Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia
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10
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Chen WY, Wu SY, Lin TC, Lin SL, Wu-Hsieh BA. Human dendritic cell-specific ICAM-3-grabbing non-integrin downstream signaling alleviates renal fibrosis via Raf-1 activation in systemic candidiasis. Cell Mol Immunol 2018; 16:288-301. [PMID: 30127380 PMCID: PMC6460490 DOI: 10.1038/s41423-018-0161-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/12/2018] [Indexed: 02/01/2023] Open
Abstract
We generated a human dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN) transgenic mouse in which renal tubular epithelial cells expressed DC-SIGN. The transgenic mice were infected with Candida albicans intravenously to study how DC-SIGN expression affected the pathogenesis of systemic candidiasis. We discovered that, while C. albicans infection induced renal fibrosis in both transgenic and littermate control mice, the transgenic mice had significantly lower levels of Acta2, Col1a2, Col3a1, and Col4a1 mRNA transcripts compared to the controls. KIM-1, an emerging biomarker for kidney injury, along with Tnf, Il6, and Tgfb1 transcripts, were lower in infected transgenic mice, and yet, the levels of Il10 remained comparable to the controls. While renal CD45+ infiltrating cells were the source of Tnf, Il6, and Il10, LTL+ renal proximal tubular epithelial cells were TGF-β1 producers in both infected transgenic and littermate controls. DC-SIGN-expressing tubular epithelial cells produced less TGF-β1 in response to C. albicans infection. In vivo experiments demonstrated that renal proximal tubular epithelial cell production of TGF-β1 was key to C. albicans-induced renal fibrosis and injury. Infection of transgenic mice induced a marked increase of phosphorylated Raf-1 and p38 in the kidney. However, ERK1/2 and JNK phosphorylation was more pronounced in the infected-littermate controls. Interestingly, treating the infected transgenic mice with a Raf-1 inhibitor increased the levels of the Tgfb1, Kim1, and Acta2 transcripts. These results indicate that DC-SIGN signaling, through activation of Raf-1 and p38 and suppression of JNK and ERK1/2 phosphorylation, reduces TGF-β1 production and C. albicans-induced renal fibrosis. Our study reveals for the first time the effect of DC-SIGN expression on C. albicans-induced renal fibrosis.
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Affiliation(s)
- Wen-Yu Chen
- Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan, China
| | - Sheng-Yang Wu
- Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan, China
| | - Ta-Chun Lin
- Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan, China
| | - Shuei-Liong Lin
- Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan, China
| | - Betty A Wu-Hsieh
- Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan, China.
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11
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Yin W, Xu S, Wang Z, Liu H, Peng L, Fang Q, Deng T, Zhang W, Lou J. Recombinant human GLP-1(rhGLP-1) alleviating renal tubulointestitial injury in diabetic STZ-induced rats. Biochem Biophys Res Commun 2017; 495:793-800. [PMID: 29137984 DOI: 10.1016/j.bbrc.2017.11.076] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 11/10/2017] [Indexed: 11/29/2022]
Abstract
GLP-1-based treatment improves glycemia through stimulation of insulin secretion and inhibition of glucagon secretion. Recently, more and more findings showed that GLP-1 could also protect kidney from diabetic nephropathy. Most of these studies focused on glomeruli, but the effect of GLP-1 on tubulointerstitial and tubule is not clear yet. In this study, we examined the renoprotective effect of recombinant human GLP-1 (rhGLP-1), and investigated the influence of GLP-1 on inflammation and tubulointerstitial injury using diabetic nephropathy rats model of STZ-induced. The results showed that rhGLP-1 reduced urinary albumin without influencing the body weight and food intake. rhGLP-1 could increased the serum C-peptide slightly but not lower fasting blood glucose significantly. In diabetic nephropathy rats, beside glomerular sclerosis, tubulointerstitial fibrosis was very serious. These lesions could be alleviated by rhGLP-1. rhGLP-1 decreased the expression of profibrotic factors collagen I, α-SMA, fibronectin, and inflammation factors MCP-1 and TNFα in tubular tissue and human proximal tubular cells (HK-2 cells). Furthermore, rhGLP-1 significantly inhibited the phosphorylation of NF-κB, MAPK in both diabetic tubular tissue and HK-2 cells. The inhibition of the expression of TNFα, MCP-1, collagen I and α-SMA in HK-2 cells by GLP-1 could be mimicked by blocking NF-κB or MAPK. These results indicate that rhGLP-1 exhibit renoprotective effect by alleviation of tubulointerstitial injury via inhibiting phosphorylation of MAPK and NF-κB. Therefore, rhGLP-1 may be a potential drug for treatment of diabetic nephropathy.
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Affiliation(s)
- Weiqin Yin
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, PR China
| | - Shiqing Xu
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Zai Wang
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Honglin Liu
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Liang Peng
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Qing Fang
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Tingting Deng
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China
| | - Wenjian Zhang
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China.
| | - Jinning Lou
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, PR China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, PR China.
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12
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Chen X, Cobbs A, George J, Chima A, Tuyishime F, Zhao X. Endocytosis of Albumin Induces Matrix Metalloproteinase-9 by Activating the ERK Signaling Pathway in Renal Tubule Epithelial Cells. Int J Mol Sci 2017; 18:ijms18081758. [PMID: 28805677 PMCID: PMC5578147 DOI: 10.3390/ijms18081758] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/06/2017] [Accepted: 08/09/2017] [Indexed: 12/25/2022] Open
Abstract
Matrix metalloproteinase-9 (MMP-9) is dysregulated in chronic kidney diseases including diabetic nephropathy. This study was performed to examine the expression of MMP-9 in renal tubule epithelial cells (TECs) under diabetic conditions and its regulatory mechanisms. We characterized MMP-9 protein in diabetic animals and primary cultured rat TECs exposed to exogenous albumin and high glucose. We also used specific inhibitors to determine if internalization of albumin and/or extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation were required for MMP-9 secretion. Immunostaining of kidney sections revealed enhanced MMP-9 signal in the damaged proximal tubules in Zucker diabetic fatty (ZDF) rats. ZDF rats also exhibited an albuminuria-related and age-dependent increase in MMP-9 excretion, which was prevented by rosiglitazone. In primary cultured rat TECs, high glucose exposure did not increase MMP-9 secretion. In contrast, administration of rat serum albumin (RSA, 0.1–0.5 mg/mL) resulted in a dose-dependent increase in MMP-9 expression and secretion by TECs, which was abolished in the presence of an ERK1/2-specific inhibitor, U0126. Simvastatin, an inhibitor of albumin endocytosis, also prevented MMP-9 secretion. Taken together, these results demonstrate that endocytosis of albumin stimulates MMP-9 secretion by TECs through the ERK signaling pathway.
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Affiliation(s)
- Xiaoming Chen
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
| | - Alyssa Cobbs
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
| | - Jasmine George
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
| | - Ashmeer Chima
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
| | - Fidele Tuyishime
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
| | - Xueying Zhao
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
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13
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Nielsen R, Christensen EI, Birn H. Megalin and cubilin in proximal tubule protein reabsorption: from experimental models to human disease. Kidney Int 2017; 89:58-67. [PMID: 26759048 DOI: 10.1016/j.kint.2015.11.007] [Citation(s) in RCA: 298] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/17/2015] [Accepted: 08/19/2015] [Indexed: 01/19/2023]
Abstract
Proximal tubule protein uptake is mediated by 2 receptors, megalin and cubilin. These receptors rescue a variety of filtered ligands, including biomarkers, essential vitamins, and hormones. Receptor gene knockout animal models have identified important functions of the receptors and have established their essential role in modulating urinary protein excretion. Rare genetic syndromes associated with dysfunction of these receptors have been identified and characterized, providing additional information on the importance of these receptors in humans. Using various disease models in combination with receptor gene knockout, the implications of receptor dysfunction in acute and chronic kidney injury have been explored and have pointed to potential new roles of these receptors. Based on data from animal models, this paper will review current knowledge on proximal tubule endocytic receptor function and regulation, and their role in renal development, protein reabsorption, albumin uptake, and normal renal physiology. These findings have implications for the pathophysiology and diagnosis of proteinuric renal diseases. We will examine the limitations of the different models and compare the findings to phenotypic observations in inherited human disorders associated with receptor dysfunction. Furthermore, evidence from receptor knockout mouse models as well as human observations suggesting a role of protein receptors for renal disease will be discussed in light of conditions such as chronic kidney disease, diabetes, and hypertension.
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Affiliation(s)
- Rikke Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Henrik Birn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark.
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14
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Nolin AC, Mulhern RM, Panchenko MV, Pisarek-Horowitz A, Wang Z, Shirihai O, Borkan SC, Havasi A. Proteinuria causes dysfunctional autophagy in the proximal tubule. Am J Physiol Renal Physiol 2016; 311:F1271-F1279. [PMID: 27582098 DOI: 10.1152/ajprenal.00125.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 08/22/2016] [Indexed: 12/29/2022] Open
Abstract
Proteinuria is a major risk factor for chronic kidney disease progression. Furthermore, exposure of proximal tubular epithelial cells to excess albumin promotes tubular atrophy and fibrosis, key predictors of progressive organ dysfunction. However, the link between proteinuria and tubular damage is unclear. We propose that pathological albumin exposure impairs proximal tubular autophagy, an essential process for recycling damaged organelles and toxic intracellular macromolecules. In both mouse primary proximal tubule and immortalized human kidney cells, albumin exposure decreased the number of autophagosomes, visualized by the autophagosome-specific fluorescent markers monodansylcadaverine and GFP-LC3, respectively. Similarly, renal cortical tissue harvested from proteinuric mice contained reduced numbers of autophagosomes on electron micrographs, and immunoblots showed reduced steady-state LC3-II content. Albumin exposure decreased autophagic flux in vitro in a concentration-dependent manner as assessed by LC3-II accumulation rate in the presence of bafilomycin, an H+-ATPase inhibitor that prevents lysosomal LC3-II degradation. In addition, albumin treatment significantly increased the half-life of radiolabeled long-lived proteins, indicating that the primary mechanism of degradation, autophagy, is dysfunctional. In vitro, mammalian target of rapamycin (mTOR) activation, a potent autophagy inhibitor, suppressed autophagy as a result of intracellular amino acid accumulation from lysosomal albumin degradation. mTOR activation was demonstrated by the increased phosphorylation of its downstream target, S6K, with free amino acid or albumin exposure. We propose that excess albumin uptake and degradation inhibit proximal tubule autophagy via an mTOR-mediated mechanism and contribute to progressive tubular injury.
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Affiliation(s)
- Angela C Nolin
- Renal Section, Department of Medicine, Boston University, Boston, Massachusetts
| | - Ryan M Mulhern
- Renal Section, Department of Medicine, Boston University, Boston, Massachusetts
| | - Maria V Panchenko
- Department of Pathology, Boston University, Boston, Massachusetts; and
| | | | - Zhiyong Wang
- Renal Section, Department of Medicine, Boston University, Boston, Massachusetts
| | - Orian Shirihai
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts
| | - Steven C Borkan
- Renal Section, Department of Medicine, Boston University, Boston, Massachusetts
| | - Andrea Havasi
- Renal Section, Department of Medicine, Boston University, Boston, Massachusetts;
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15
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Jarad G, Knutsen RH, Mecham RP, Miner JH. Albumin contributes to kidney disease progression in Alport syndrome. Am J Physiol Renal Physiol 2016; 311:F120-30. [PMID: 27147675 DOI: 10.1152/ajprenal.00456.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 04/29/2016] [Indexed: 12/31/2022] Open
Abstract
Alport syndrome is a familial kidney disease caused by defects in the collagen type IV network of the glomerular basement membrane. Lack of collagen-α3α4α5(IV) changes the glomerular basement membrane morphologically and functionally, rendering it leaky to albumin and other plasma proteins. Filtered albumin has been suggested to be a cause of the glomerular and tubular injuries observed at advanced stages of Alport syndrome. To directly investigate the role that albumin plays in the progression of disease in Alport syndrome, we generated albumin knockout (Alb(-/-)) mice to use as a tool for removing albuminuria as a component of kidney disease. Mice lacking albumin were healthy and indistinguishable from control littermates, although they developed hypertriglyceridemia. Dyslipidemia was observed in Alb(+/-) mice, which displayed half the normal plasma albumin concentration. Alb mutant mice were bred to collagen-α3(IV) knockout (Col4a3(-/-)) mice, which are a model for human Alport syndrome. Lack of circulating and filtered albumin in Col4a3(-/-);Alb(-/-) mice resulted in dramatically improved kidney disease outcomes, as these mice lived 64% longer than did Col4a3(-/-);Alb(+/+) and Col4a3(-/-);Alb(+/-) mice, despite similar blood pressures and serum triglyceride levels. Further investigations showed that the absence of albumin correlated with reduced transforming growth factor-β1 signaling as well as reduced tubulointerstitial, glomerular, and podocyte pathology. We conclude that filtered albumin is injurious to kidney cells in Alport syndrome and perhaps in other proteinuric kidney diseases, including diabetic nephropathy.
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Affiliation(s)
- George Jarad
- Division of Nephrology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri; and
| | - Russell H Knutsen
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Robert P Mecham
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Jeffrey H Miner
- Division of Nephrology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri; and Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
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16
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Heerspink HJL, Ninomiya T, Persson F, Brenner BM, Brunel P, Chaturvedi N, Desai AS, Haffner SM, Mcmurray JJV, Solomon SD, Pfeffer MA, Parving HH, de Zeeuw D. Is a reduction in albuminuria associated with renal and cardiovascular protection? A post hoc analysis of the ALTITUDE trial. Diabetes Obes Metab 2016; 18:169-77. [PMID: 26511599 DOI: 10.1111/dom.12600] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/24/2015] [Accepted: 10/24/2015] [Indexed: 01/23/2023]
Abstract
AIMS To investigate whether the degree of albuminuria reduction observed in the ALTITUDE trial is associated with renal and cardiovascular protection, and secondly, whether the reduction in albuminuria was too small to afford clinical benefit. METHODS In a post hoc analysis of the ALTITUDE trial in 8561 patients with type 2 diabetes and chronic kidney disease or cardiovascular disease we examined the effect of albuminuria changes at 6 months on renal and cardiovascular outcomes using Cox proportional hazard regression. RESULTS The median change in albuminuria in the first 6 months in the aliskiren arm of the trial was -12% (25th to 75th percentile: -48.7_to_ +41.9%) and 0.0% (25th to 75th percentile: -40.2_to_55%) in the placebo arm. Changes in albuminuria in the first 6 months were linearly associated with renal and cardiovascular endpoints: a >30% reduction in albuminuria in the first 6 months was associated with a 62% reduction in renal risk and a 25% reduction in cardiovascular risk compared with an increase in albuminuria. The association between changes at 6 months in albuminuria and renal or cardiovascular endpoints was similar in the two treatment groups (p for interaction >0.1 for both endpoints). CONCLUSIONS The addition of aliskiren to angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy resulted in albuminuria changes that were associated with renal and cardiovascular risk changes. This did not translate into renal or cardiovascular protection because the overall reduction in albuminuria in the aliskiren arm was too small and nearly similar to that in the placebo arm.
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Affiliation(s)
- H J L Heerspink
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - T Ninomiya
- Division of Research Management, Center for Cohort Studies Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - F Persson
- Steno Diabetes Centre, Gentofte, Denmark
| | - B M Brenner
- Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - P Brunel
- Novartis Pharma AB, Global Medical Affairs, Basel, Switzerland
| | - N Chaturvedi
- Institute of Cardiovascular Sciences, University College London, London, UK
| | - A S Desai
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - S M Haffner
- Department of Medicine and Clinical Epidemiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - J J V Mcmurray
- British Heart Foundation Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - S D Solomon
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - M A Pfeffer
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - H-H Parving
- Department of Medical Endocrinology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - D de Zeeuw
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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17
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Cárdenas A, Campos J, Ehrenfeld P, Mezzano S, Ruiz-Ortega M, Figueroa CD, Ardiles L. Up-regulation of the kinin B2 receptor pathway modulates the TGF-β/Smad signaling cascade to reduce renal fibrosis induced by albumin. Peptides 2015; 73:7-19. [PMID: 26256678 DOI: 10.1016/j.peptides.2015.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 07/09/2015] [Accepted: 08/04/2015] [Indexed: 12/24/2022]
Abstract
The presence of high protein levels in the glomerular filtrate plays an important role in renal fibrosis, a disorder that justifies the use of animal models of experimental proteinuria. Such models have proved useful as tools in the study of the pathogenesis of chronic, progressive renal disease. Since bradykinin and the kinin B2 receptor (B2R) belong to a renoprotective system with mechanisms still unclarified, we investigated its anti-fibrotic role in the in vivo rat model of overload proteinuria. Upon up-regulating the kinin system by a high potassium diet we observed reduction of tubulointerstitial fibrosis, decreased renal expression of α-smooth muscle actin (α-SMA) and vimentin, reduced Smad3 phosphorylation and increase of Smad7. These cellular and molecular effects were reversed by HOE-140, a specific B2R antagonist. In vitro experiments, performed on a cell line of proximal tubular epithelial cells, showed that high concentrations of albumin induced expression of mesenchymal biomarkers, in concomitance with increases in TGF-β1 mRNA and its functionally active peptide, TGF-β1. Stimulation of the tubule cells by bradykinin inhibited the albumin-induced changes, namely α-SMA and vimentin were reduced, and cytokeratin recovered together with increase in Smad7 levels and decrease in type II TGF-β1 receptor, TGF-β1 mRNA and its active fragment. The protective changes produced by bradykinin in vitro were blocked by HOE-140. The development of stable bradykinin analogues and/or up-regulation of the B2R signaling pathway may prove value in the management of chronic renal fibrosis in progressive proteinuric renal diseases.
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Affiliation(s)
- Areli Cárdenas
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile
| | - Javiera Campos
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Ehrenfeld
- Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia, Chile
| | - Sergio Mezzano
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile
| | - Marta Ruiz-Ortega
- IIS-Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Carlos D Figueroa
- Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia, Chile
| | - Leopoldo Ardiles
- Department of Nephrology, Universidad Austral de Chile, Valdivia, Chile.
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18
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The Mechanisms of Human Renal Epithelial Cell Modulation of Autologous Dendritic Cell Phenotype and Function. PLoS One 2015; 10:e0134688. [PMID: 26230727 PMCID: PMC4521940 DOI: 10.1371/journal.pone.0134688] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/13/2015] [Indexed: 01/08/2023] Open
Abstract
Proximal tubule epithelial cells (PTEC) of the kidney line the proximal tubule downstream of the glomerulus and play a major role in the re-absorption of small molecular weight proteins that may pass through the glomerular filtration process. In the perturbed disease state PTEC also contribute to the inflammatory disease process via both positive and negative mechanisms via the production of inflammatory cytokines which chemo-attract leukocytes and the subsequent down-modulation of these cells to prevent uncontrolled inflammatory responses. It is well established that dendritic cells are responsible for the initiation and direction of adaptive immune responses. Both resident and infiltrating dendritic cells are localised within the tubulointerstitium of the renal cortex, in close apposition to PTEC, in inflammatory disease states. We previously demonstrated that inflammatory PTEC are able to modulate autologous human dendritic cell phenotype and functional responses. Here we extend these findings to characterise the mechanisms of this PTEC immune-modulation using primary human PTEC and autologous monocyte-derived dendritic cells (MoDC) as the model system. We demonstrate that PTEC express three inhibitory molecules: (i) cell surface PD-L1 that induces MoDC expression of PD-L1; (ii) intracellular IDO that maintains the expression of MoDC CD14, drives the expression of CD80, PD-L1 and IL-10 by MoDC and inhibits T cell stimulatory capacity; and (iii) soluble HLA-G (sHLA-G) that inhibits HLA-DR and induces IL-10 expression by MoDC. Collectively the results demonstrate that primary human PTEC are able to modulate autologous DC phenotype and function via multiple complex pathways. Further dissection of these pathways is essential to target therapeutic strategies in the treatment of inflammatory kidney disorders.
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19
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Lambers Heerspink HJ, Gansevoort RT. Albuminuria Is an Appropriate Therapeutic Target in Patients with CKD: The Pro View. Clin J Am Soc Nephrol 2015; 10:1079-88. [PMID: 25887073 DOI: 10.2215/cjn.11511114] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The presence of elevated levels of albuminuria is associated with an increased risk of progressive renal function loss over time. This association is found in various pathophysiological conditions, including diabetic nephropathy, hypertensive nephropathy, and various primary renal diseases, but also, the general, otherwise healthy population. Emerging data report that elevated albuminuria causes tubulointerstitial damage through activation of proinflammatory mediators, which ultimately leads to a progressive decline in renal function. Nowadays, various drugs are available that decrease the rate of GFR loss in patients with kidney disease. Well known are renin-angiotensin-aldosterone system inhibitors, but there are also other drugs and interventions, like intensive glucose control, anti-inflammatory agents (pentoxifylline), or a low-protein diet. These interventions have an additional effect beyond their original target, namely lowering albuminuria. Analyses from clinical trials show that the reduction in albuminuria observed during the first months of treatment with these drugs correlates with the degree of long-term renal protection: the larger the initial reduction in albuminuria, the lower the risk of ESRD during treatment. In addition, in treated patients, residual albuminuria is again the strongest risk marker for renal disease progression. These observations combined provide a strong argument that albuminuria is an appropriate therapeutic target in patients with CKD.
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Affiliation(s)
| | - Ron T Gansevoort
- Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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20
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Slattery C, Jang Y, Kruger WA, Hryciw DH, Lee A, Poronnik P. γ-Secretase inhibition promotes fibrotic effects of albumin in proximal tubular epithelial cells. Br J Pharmacol 2014; 169:1239-51. [PMID: 23594166 DOI: 10.1111/bph.12214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 01/24/2013] [Accepted: 02/20/2013] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE Albuminuria is an important biomarker of renal dysfunction and is a major mediator of renal damage and fibrosis during kidney disease. The mechanisms underlying albumin-induced renal fibrosis remain unclear. There has been significant interest in γ-secretase activity in tubular epithelial cells in recent times; however, its potential role in albumin-induced fibrosis has not been investigated. EXPERIMENTAL APPROACH The primary aim of this study was to examine the role of γ-secretase in albumin-induced fibrotic effects in proximal tubular cells. The effects of increasing albumin concentrations on fibrosis indicators and mediators in the human HK-2 cell line were examined in the presence and absence of a γ-secretase inhibitor, compound E. KEY RESULTS Treatment with albumin resulted in a number of pro-fibrotic effects, including up-regulation of fibronectin, TGF-β1 and the EGF-R. Interestingly, similar effects were observed in response to treatment with the γ-secretase inhibitor, compound E. Co-treatment of cells with albumin and an EGF-R inhibitor, AG-1478, resulted in significant inhibition of the observed pro-fibrotic effects, suggesting a major role for the EGF-R in albumin-induced fibrotic events. Albumin-induced effects on the EGF-R appeared to be mediated through inhibition of γ-secretase activity and were dependent on ERK-MAPK signalling. CONCLUSIONS AND IMPLICATIONS These results provide novel insights into the mechanisms of albumin-induced fibrotic effects in tubular epithelial cells, suggesting important roles for the γ-secretase and the EGF-R. These results suggest that the proposed use of γ-secretase inhibitors as anti-fibrotic agents requires further investigation.
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Affiliation(s)
- C Slattery
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Belfield, Ireland
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21
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Microalbuminuria: target for renoprotective therapy PRO. Kidney Int 2014; 86:40-9. [DOI: 10.1038/ki.2013.490] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 08/19/2013] [Accepted: 08/22/2013] [Indexed: 12/23/2022]
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22
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Pawluczyk IZA, Pervez A, Ghaderi Najafabadi M, Saleem MA, Topham PS. The effect of albumin on podocytes: the role of the fatty acid moiety and the potential role of CD36 scavenger receptor. Exp Cell Res 2014; 326:251-8. [PMID: 24815572 DOI: 10.1016/j.yexcr.2014.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 04/07/2014] [Accepted: 04/21/2014] [Indexed: 10/25/2022]
Abstract
Evidence is emerging that podocytes are able to endocytose proteins such as albumin using kinetics consistent with a receptor-mediated process. To date the role of the fatty acid moiety on albumin uptake kinetics has not been delineated and the receptor responsible for uptake is yet to be identified. Albumin uptake studies were carried out on cultured human podocytes exposed to FITC-labelled human serum albumin either carrying fatty acids (HSA+FA) or depleted of them (HSA-FA). Receptor-mediated endocytosis of FITC-HSA+FA over 60 min was 5 times greater than that of FITC-HSA-FA. 24h exposure of podocytes to albumin up-regulated nephrin expression and induced the activation of caspase-3. These effects were more pronounced in response to HSA-FA. Individually, anti-CD36 antibodies had no effect upon endocytosis of FITC-HSA. However, a cocktail of 2 antibodies reduced uptake by nearly 50%. Albumin endocytosis was enhanced in the presence of the CD36 specific inhibitor sulfo-N-succinimidyl oleate (SSO) while knock-down of CD36 using CD36siRNA had no effect on uptake. These data suggest that receptor-mediated endocytosis of albumin by podocytes is regulated by the fatty acid moiety, although, some of the detrimental effects are induced independently of it. CD36 does not play a direct role in the uptake of albumin.
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Affiliation(s)
- I Z A Pawluczyk
- Department of Infection, Immunity and inflammation, University of Leicester, Leicester, UK; John Walls Renal Unit, Leicester General Hospital Leicester, UK.
| | - A Pervez
- Department of Infection, Immunity and inflammation, University of Leicester, Leicester, UK
| | - M Ghaderi Najafabadi
- Department of Infection, Immunity and inflammation, University of Leicester, Leicester, UK
| | - M A Saleem
- Academic and Children׳s Renal Unit, University of Bristol, Southmead Hospital, Bristol, UK
| | - P S Topham
- Department of Infection, Immunity and inflammation, University of Leicester, Leicester, UK; John Walls Renal Unit, Leicester General Hospital Leicester, UK
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23
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Wilkinson R, Wang X, Kassianos AJ, Zuryn S, Roper KE, Osborne A, Sampangi S, Francis L, Raghunath V, Healy H. Laser capture microdissection and multiplex-tandem PCR analysis of proximal tubular epithelial cell signaling in human kidney disease. PLoS One 2014; 9:e87345. [PMID: 24475278 PMCID: PMC3903679 DOI: 10.1371/journal.pone.0087345] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 12/19/2013] [Indexed: 02/06/2023] Open
Abstract
Interstitial fibrosis, a histological process common to many kidney diseases, is the precursor state to end stage kidney disease, a devastating and costly outcome for the patient and the health system. Fibrosis is historically associated with chronic kidney disease (CKD) but emerging evidence is now linking many forms of acute kidney disease (AKD) with the development of CKD. Indeed, we and others have observed at least some degree of fibrosis in up to 50% of clinically defined cases of AKD. Epithelial cells of the proximal tubule (PTEC) are central in the development of kidney interstitial fibrosis. We combine the novel techniques of laser capture microdissection and multiplex-tandem PCR to identify and quantitate "real time" gene transcription profiles of purified PTEC isolated from human kidney biopsies that describe signaling pathways associated with this pathological fibrotic process. Our results: (i) confirm previous in-vitro and animal model studies; kidney injury molecule-1 is up-regulated in patients with acute tubular injury, inflammation, neutrophil infiltration and a range of chronic disease diagnoses, (ii) provide data to inform treatment; complement component 3 expression correlates with inflammation and acute tubular injury, (iii) identify potential new biomarkers; proline 4-hydroxylase transcription is down-regulated and vimentin is up-regulated across kidney diseases, (iv) describe previously unrecognized feedback mechanisms within PTEC; Smad-3 is down-regulated in many kidney diseases suggesting a possible negative feedback loop for TGF-β in the disease state, whilst tight junction protein-1 is up-regulated in many kidney diseases, suggesting feedback interactions with vimentin expression. These data demonstrate that the combined techniques of laser capture microdissection and multiplex-tandem PCR have the power to study molecular signaling within single cell populations derived from clinically sourced tissue.
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Affiliation(s)
- Ray Wilkinson
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- Medical School, University of Queensland, Brisbane, Queensland, Australia
| | - Xiangju Wang
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Andrew J. Kassianos
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Steven Zuryn
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Kathrein E. Roper
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Andrew Osborne
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Sandeep Sampangi
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Leo Francis
- Pathology Queensland, Brisbane, Queensland, Australia
| | - Vishwas Raghunath
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Helen Healy
- Conjoint Kidney Research Laboratory, Pathology Queensland, Brisbane, Queensland, Australia
- Department of Renal Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
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McMahon GM, O'Seaghdha CM, Hwang SJ, Meigs JB, Fox CS. The association of a single-nucleotide polymorphism in CUBN and the risk of albuminuria and cardiovascular disease. Nephrol Dial Transplant 2013; 29:342-7. [PMID: 24052458 DOI: 10.1093/ndt/gft386] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Albuminuria is an important risk factor for cardiovascular disease (CVD). We have previously identified a missense single-nucleotide polymorphism (rs1801239) in the CUBN gene that is associated with albuminuria. Whether albuminuria is associated with CVD in the presence of the CUBN mutation is unknown. METHODS We analyzed participants from the Framingham Heart Study (n=6399, mean age 47 years, 53.4% women) who underwent genotyping of rs1801239. Cox proportional hazards models were used to test the association between microalbuminuria [UACR≥17 mg/g (men) and ≥25 mg/g (women)] and incident CVD stratified by the presence or absence of the CUBN risk allele. We tested whether the association between microalbuminuria and CVD was altered by the presence of the risk allele with interaction testing. RESULTS Overall, 21.1% of participants carried the risk allele. As expected, carriers of the risk (C) allele had a higher prevalence of microalbuminuria (10.7 versus 8.9%, P=0.04). During a mean follow-up of 10.4 years, 5.6% (n=346) of participants experienced a CVD event. Microalbuminuria was associated with an increased risk of CVD [hazards ratio (HR) 1.46, 95% confidence interval (CI) 1.14-1.88]. When stratified by risk allele carrier status, the HR for CVD was 1.95 (95% CI 1.15-3.29) among those with compared to 1.33 (95% CI 1.00-1.76) among those without the risk allele. There was no interaction between microalbuminuria and rs1801239 on CVD (Pinteraction=0.49). CONCLUSIONS MA is associated with CVD irrespective of the presence of the CUBN risk allele. These results challenge the concept that albuminuria in the setting of this mutation is benign.
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Affiliation(s)
- Gearoid M McMahon
- National Heart, Lung and Blood Institute's Framingham Heart Study and the Center for Population Studies, Framingham, MA, USA
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25
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Sengul S, Erturk S, Khan AM, Batuman V. Receptor-associated protein blocks internalization and cytotoxicity of myeloma light chain in cultured human proximal tubular cells. PLoS One 2013; 8:e70276. [PMID: 23894629 PMCID: PMC3720907 DOI: 10.1371/journal.pone.0070276] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 06/19/2013] [Indexed: 12/01/2022] Open
Abstract
Background Free light chains (LCs) are among the many ligands that bind to cubilin/megalin for endocytosis via the clathrin-dependent endosomal/lysosomal pathway. Receptor associated protein (RAP), is a 39 kDA high-affinity, chaperone-like ligand for megalin that assists in the proper folding and functioning of megalin/cubilin. Although RAP is known to inhibit ligand binding to megalin/cubilin, its effect on LC endocytosis has not been shown directly. Methods and Principal Findings We investigated whether RAP can block the endocytosis of LC in cultured human proximal tubule cells and whether this can prevent LC cytotoxicity. Immunofluorescence microscopy and flow cytometry showed that fluorescently labeled LC endocytosis was markedly inhibited in HK-2 cells pretreated with human RAP. The effect of RAP was dose-dependent, and was predominantly on endocytosis as it had no effect on the small acid-washable fraction of LC bound to cell membrane. RAP significantly inhibited LC induced cytokine production and phosphorylation of ERK1/2 and p38 MAPK. Prolonged exposure to LC for 48 h resulted in epithelial-to-mesenchymal transformation in HK-2 cells as evidenced by marked reduction in the expression of the epithelial cell marker E-cadherin, and increased the expression of the mesenchymal marker α-SMA, which was also prevented by RAP in the endocytosis medium. Conclusions RAP inhibited LC endocytosis by ∼88% and ameliorated LC-induced cytokine responses and EMT in human PTCs. The results not only provide additional evidence that LCs endocytosis occurs via the megalin/cubilin endocytic receptor system, but also show that blocking LC endocytosis by RAP can protect proximal tubule cells from LC cytotoxicity.
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Affiliation(s)
- Sule Sengul
- Department of Nephrology, Ankara University School of Medicine, Ankara, Turkey
| | - Sehsuvar Erturk
- Department of Nephrology, Ankara University School of Medicine, Ankara, Turkey
| | - Altaf M. Khan
- Division of Nephrology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Vecihi Batuman
- Division of Nephrology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
- SLVHCS, VA Medical Center, New Orleans, Louisiana, United States of America
- * E-mail:
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26
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Beta-lactam antibiotics modulate T-cell functions and gene expression via covalent binding to cellular albumin. Proc Natl Acad Sci U S A 2013; 110:2981-6. [PMID: 23382225 DOI: 10.1073/pnas.1215722110] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recent work has suggested that beta-lactam antibiotics might directly affect eukaryotic cellular functions. Here, we studied the effects of commonly used beta-lactam antibiotics on rodent and human T cells in vitro and in vivo on T-cell-mediated experimental autoimmune diseases. We now report that experimental autoimmune encephalomyelitis and adjuvant arthritis were significantly more severe in rats treated with cefuroxime and other beta-lactams. T cells appeared to mediate the effect: an anti-myelin basic protein T-cell line treated with cefuroxime or penicillin was more encephalitogenic in adoptive transfer experiments. The beta-lactam ampicillin, in contrast to cefuroxime and penicillin, did not enhance encephalomyelitis, but did inhibit the autoimmune diabetes developing spontaneously in nonobese diabetic mice. Gene expression analysis of human peripheral blood T cells showed that numerous genes associated with T helper 2 (Th2) and T regulatory (Treg) differentiation were down-regulated in T cells stimulated in the presence of cefuroxime; these genes were up-regulated in the presence of ampicillin. The T-cell protein that covalently bound beta-lactam antibiotics was found to be albumin. Human and rodent T cells expressed albumin mRNA and protein, and penicillin-modified albumin was taken up by rat T cells, leading to enhanced encephalitogenicity. Thus, beta-lactam antibiotics in wide clinical use have marked effects on T-cell behavior; beta-lactam antibiotics can function as immunomodulators, apparently through covalent binding to albumin.
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27
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Glomerular and tubular dysfunctions and their relationship to adiponectin and oxidative stress in obese subjects. Int J Organ Transplant Med 2012. [DOI: 10.1016/j.hkjn.2012.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Christensen EI, Birn H, Storm T, Weyer K, Nielsen R. Endocytic Receptors in the Renal Proximal Tubule. Physiology (Bethesda) 2012; 27:223-36. [DOI: 10.1152/physiol.00022.2012] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Protein reabsorption is a predominant feature of the renal proximal tubule. Animal studies show that the ability to rescue plasma proteins relies on the endocytic receptors megalin and cubilin. Recently, studies of patients with syndromes caused by dysfunctional receptors have supported the importance of these for protein clearance of human ultrafiltrate. This review focuses on the molecular biology and physiology of the receptors and their involvement in renal pathological conditions.
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Affiliation(s)
- Erik I. Christensen
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Henrik Birn
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Tina Storm
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Kathrin Weyer
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Rikke Nielsen
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
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29
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Youn YS, Lim HH, Lee JH. The clinical characteristics of steroid responsive nephrotic syndrome of children according to the serum immunoglobulin E levels and cytokines. Yonsei Med J 2012; 53:715-22. [PMID: 22665336 PMCID: PMC3381495 DOI: 10.3349/ymj.2012.53.4.715] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE The nephrotic syndrome (NS) is characterized by the favorable response to glucocorticoid therapy and the development of NS may be associated with dysfunctional immune systems. In order to investigate the serum immunoglobulin E (IgE) levels and cytokines activity in pediatric NS, the total of 32 steroid responsive NS patients and 5 healthy controls were enrolled in this study. MATERIALS AND METHODS All patients were divided into two groups according to the initial serum IgE levels, such as normal and high IgE group, and their clinical characteristics were evaluated. In addition, serum levels of interleukin (IL)-4, IL-5, IL-10 and transforming growth factor (TGF)-β were compared and correlated with serum albumin, proteinuria by means of disease severity, and cytokines. RESULTS In the high IgE group, the higher comorbidity of allergic diseases and relapsing rate, the longer duration of steroid therapy before initial remission, and the higher serum IL-4 and IL-5 levels were found. In all patients, initially higher serum levels of IL-4 and IL-5 declined to normal levels after steroid therapy, whereas the serum IL-10 levels showed no significant difference between nephrotic phase (heavy proteinuria) and remission phase (no proteinuria) of NS. The serum TGF-β levels of the nephrotic phase were significantly lower than those of remission phase or control group, and returned to normal control levels after steroid therapy. CONCLUSION This study indicates that initial IgE level is associated with steroid responsiveness and disease severity, and cytokine activities may also be related to the pathogenesis of pediatric steroid responsive NS.
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Affiliation(s)
- You Sook Youn
- Department of Pediatrics, Deajeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, Korea
| | - Han Hyuk Lim
- Department of Pediatrics, Chungnam National University School of Medicine, Daejeon, Korea
| | - Jae Ho Lee
- Department of Pediatrics, Chungnam National University School of Medicine, Daejeon, Korea
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30
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Tang SCW, Lai KN. The pathogenic role of the renal proximal tubular cell in diabetic nephropathy. Nephrol Dial Transplant 2012; 27:3049-56. [PMID: 22734110 DOI: 10.1093/ndt/gfs260] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A growing body of evidence indicates that the renal proximal tubular epithelial cell (PTEC) plays an important role in the pathogenesis of diabetic nephropathy (DN). Microalbuminuria that intensifies over time to overt proteinuria, a hallmark of DN, is already known to activate the PTEC to induce tubulointerstitial inflammation. In addition to proteins, a number of diabetic substrates including high glucose per se, advanced glycation end-products and their carbonyl intermediates, angiotensin II, and ultrafiltered growth factors activate a number of signaling pathways including nuclear factor kappa B, protein kinase C, extracellular signal-regulated kinase 1/2, p38, signal transducer and activator of transcription-1 and the generation of reactive oxygen species, to culminate in tubular cell hypertrophy and the accumulation in the interstitium of a repertoire of chemokines, cytokines, growth factors and adhesion molecules capable of orchestrating further inflammation and fibrosis. More recently, the kallikrein-kinin system (KKS) and toll-like receptors (TLRs) in PTECs have been implicated in this process. While in vitro data suggest that the KKS contributes to the progression of DN, there are conflicting in vivo results on its precise role, which may in part be strain-dependent. On the other hand, there are both in vitro and in vivo data to suggest a role for both TLR2 and TLR4 in DN. In this review, we offer a critical appraisal of the events linking the participation of the PTEC to the pathogenesis of DN, which we believe may be collectively termed diabetic tubulopathy.
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Affiliation(s)
- Sydney C W Tang
- Division of Nephrology, Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China.
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31
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Chang AM, Ohse T, Krofft RD, Wu JS, Eddy AA, Pippin JW, Shankland SJ. Albumin-induced apoptosis of glomerular parietal epithelial cells is modulated by extracellular signal-regulated kinase 1/2. Nephrol Dial Transplant 2011; 27:1330-43. [PMID: 21896500 DOI: 10.1093/ndt/gfr483] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The biological role(s) of glomerular parietal epithelial cells (PECs) is not fully understood in health or disease. Given its location, PECs are constantly exposed to low levels of filtered albumin, which is increased in nephrotic states. We tested the hypothesis that PECs internalize albumin and increased uptake results in apoptosis. METHODS Confocal microscopy of immunofluorescent staining and immunohistochemistry were used to demonstrate albumin internalization in PECs and to quantitate albumin uptake in normal mice and rats as well as experimental models of membranous nephropathy, minimal change disease/focal segmental glomerulosclerosis and protein overload nephropathy. Fluorescence-activated cell sorting analysis was performed on immortalized cultured PECs exposed to fluorescein isothiocyanate (FITC)-labeled albumin in the presence of an endosomal inhibitor or vehicle. Apoptosis was measured by Hoechst staining in cultured PECs exposed to bovine serum albumin. Levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (p-ERK1/2) were restored by retroviral infection of mitogen-activated protein kinase (MEK) 1/2 and reduced by U0126 in PECs exposed to high albumin levels in culture and apoptosis measured by Hoechst staining. RESULTS PECs internalized albumin normally, and this was markedly increased in all of the experimental disease models (P<0.05 versus controls). Cultured immortalized PECs also internalize FITC-labeled albumin, which was reduced by endosomal inhibition. A consequence of increased albumin internalization was PEC apoptosis in vitro and in vivo. Candidate signaling pathways underlying these events were examined. Data showed markedly reduced levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (ERK1/2) in PECs exposed to high albumin levels in nephropathy and in culture. A role for ERK1/2 in limiting albumin-induced apoptosis was shown by restoring p-ERK1/2 by retroviral infection, which reduced apoptosis in cultured PECs, while a forced decrease of p-ERK1/2 through inhibition of MEK 1/2 significantly increased albumin-induced PEC apoptosis. CONCLUSIONS A normal role of PECs is to take up filtered albumin. However, this is increased in proteinuric glomerular diseases, leading to apoptosis through changes in ERK1/2.
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Affiliation(s)
- Alice M Chang
- University of Washington, and Seattle Children's Hospital and Research Institute, Seattle, WA, USA.
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32
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Böger CA, Chen MH, Tin A, Olden M, Köttgen A, de Boer IH, Fuchsberger C, O'Seaghdha CM, Pattaro C, Teumer A, Liu CT, Glazer NL, Li M, O'Connell JR, Tanaka T, Peralta CA, Kutalik Z, Luan J, Zhao JH, Hwang SJ, Akylbekova E, Kramer H, van der Harst P, Smith AV, Lohman K, de Andrade M, Hayward C, Kollerits B, Tönjes A, Aspelund T, Ingelsson E, Eiriksdottir G, Launer LJ, Harris TB, Shuldiner AR, Mitchell BD, Arking DE, Franceschini N, Boerwinkle E, Egan J, Hernandez D, Reilly M, Townsend RR, Lumley T, Siscovick DS, Psaty BM, Kestenbaum B, Haritunians T, Bergmann S, Vollenweider P, Waeber G, Mooser V, Waterworth D, Johnson AD, Florez JC, Meigs JB, Lu X, Turner ST, Atkinson EJ, Leak TS, Aasarød K, Skorpen F, Syvänen AC, Illig T, Baumert J, Koenig W, Krämer BK, Devuyst O, Mychaleckyj JC, Minelli C, Bakker SJ, Kedenko L, Paulweber B, Coassin S, Endlich K, Kroemer HK, Biffar R, Stracke S, Völzke H, Stumvoll M, Mägi R, Campbell H, Vitart V, Hastie ND, Gudnason V, Kardia SL, Liu Y, Polasek O, Curhan G, Kronenberg F, Prokopenko I, Rudan I, Ärnlöv J, Hallan S, Navis G, Parsa A, Ferrucci L, Coresh J, Shlipak MG, Bull SB, Paterson AD, Wichmann HE, Wareham NJ, Loos RJ, Rotter JI, Pramstaller PP, Cupples LA, Beckmann JS, Yang Q, Heid IM, Rettig R, Dreisbach AW, Bochud M, Fox CS, Kao W. CUBN is a gene locus for albuminuria. J Am Soc Nephrol 2011; 22:555-70. [PMID: 21355061 PMCID: PMC3060449 DOI: 10.1681/asn.2010060598] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 10/19/2010] [Indexed: 11/03/2022] Open
Abstract
Identification of genetic risk factors for albuminuria may alter strategies for early prevention of CKD progression, particularly among patients with diabetes. Little is known about the influence of common genetic variants on albuminuria in both general and diabetic populations. We performed a meta-analysis of data from 63,153 individuals of European ancestry with genotype information from genome-wide association studies (CKDGen Consortium) and from a large candidate gene study (CARe Consortium) to identify susceptibility loci for the quantitative trait urinary albumin-to-creatinine ratio (UACR) and the clinical diagnosis microalbuminuria. We identified an association between a missense variant (I2984V) in the CUBN gene, which encodes cubilin, and both UACR (P = 1.1 × 10(-11)) and microalbuminuria (P = 0.001). We observed similar associations among 6981 African Americans in the CARe Consortium. The associations between this variant and both UACR and microalbuminuria were significant in individuals of European ancestry regardless of diabetes status. Finally, this variant associated with a 41% increased risk for the development of persistent microalbuminuria during 20 years of follow-up among 1304 participants with type 1 diabetes in the prospective DCCT/EDIC Study. In summary, we identified a missense CUBN variant that associates with levels of albuminuria in both the general population and in individuals with diabetes.
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Affiliation(s)
- Carsten A. Böger
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
| | - Ming-Huei Chen
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
| | - Adrienne Tin
- Department of Epidemiology and the Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland
| | - Matthias Olden
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
- Department of Epidemiology and Preventive Medicine, Regensburg University Medical Center, Regensburg, Germany
| | - Anna Köttgen
- Department of Epidemiology and the Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland
- Renal Division, University Hospital of Freiburg, Freiburg, Germany
| | - Ian H. de Boer
- Division of Nephrology, University of Washington, Seattle, Washington
| | - Christian Fuchsberger
- Institute of Genetic Medicine, European Academy of Bolzano/Bozen (EURAC), Italy and Affiliated Institute of the University of Lübeck, Lübeck, Germany
| | - Conall M. O'Seaghdha
- Division of Nephrology, Brigham and Women's Hospital and Harvard Medical School, Boston Massachusetts
| | - Cristian Pattaro
- Institute of Genetic Medicine, European Academy of Bolzano/Bozen (EURAC), Italy and Affiliated Institute of the University of Lübeck, Lübeck, Germany
| | - Alexander Teumer
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Ching-Ti Liu
- Department of Biostatistics, Boston University School of Public Health and NHLBI's Framingham Heart Study, Boston Massachusetts
| | - Nicole L. Glazer
- Cardiovascular Health Research Unit and Department of Biostatistics, University of Washington, Seattle, Washington
| | - Man Li
- Department of Epidemiology and the Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland
| | | | - Toshiko Tanaka
- Medstar Research Institute, Baltimore, Maryland
- Clinical Research Branch, National Institute on Aging, Baltimore, Maryland
| | - Carmen A. Peralta
- Division of Nephrology, University of California, San Francisco Medical School and San Francisco VA Medical Center, San Francisco, California
| | - Zoltán Kutalik
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Jian'an Luan
- MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Jing Hua Zhao
- MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Shih-Jen Hwang
- NHLBI's Framingham Heart Study and the Center for Population Studies, Framingham, Massachusetts
| | | | | | - Pim van der Harst
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Albert V. Smith
- University of Iceland, Reykjavik, Iceland
- Icelandic Heart Association, Hjartavernd, Holtasmara, Kopavogur, Iceland
| | - Kurt Lohman
- Department of Biostatistical Sciences, Wake Forest University, Division of Public Health Sciences, Winston-Salem, North Carolina
| | - Mariza de Andrade
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Caroline Hayward
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland
| | - Barbara Kollerits
- Innsbruck Medical University, Division of Genetic Epidemiology, Innsbruck, Austria
| | - Anke Tönjes
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Thor Aspelund
- University of Iceland, Reykjavik, Iceland
- Icelandic Heart Association, Hjartavernd, Holtasmara, Kopavogur, Iceland
| | - Erik Ingelsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Gudny Eiriksdottir
- Icelandic Heart Association, Hjartavernd, Holtasmara, Kopavogur, Iceland
| | - Lenore J. Launer
- Laboratory of Epidemiology, Demography, and Biometry, NIA, Bethesda, Maryland
| | - Tamara B. Harris
- Laboratory of Epidemiology, Demography, and Biometry, NIA, Bethesda, Maryland
| | - Alan R. Shuldiner
- University of Maryland School of Medicine, Geriatric Research and Education Clinical Center, Veterans Administration Medical Center, Baltimore, Maryland
| | | | - Dan E. Arking
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Nora Franceschini
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Eric Boerwinkle
- Human Genetics Center, University of Texas Health Science Center, Houston, Texas
| | - Josephine Egan
- Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, Maryland
| | - Dena Hernandez
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, Maryland
| | - Muredach Reilly
- University of Pennsylvania Division of Cardiology, Perelman Center for Advanced Medicine, Philadelphia, Pennsylvania
| | - Raymond R. Townsend
- University of Pennsylvania Renal Electrolyte and Hypertension Division, Philadelphia, Pennsylvania
| | - Thomas Lumley
- Cardiovascular Health Research Unit and Department of Biostatistics, University of Washington, Seattle, Washington
| | - David S. Siscovick
- Departments of Epidemiology and Medicine, University of Washington, Seattle, Washington
| | - Bruce M. Psaty
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology, and Health Services and Group Health Research Institute, Group Health Cooperative, Seattle, Washington
| | - Bryan Kestenbaum
- Division of Nephrology, University of Washington, Seattle, Washington
| | - Talin Haritunians
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Sven Bergmann
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Peter Vollenweider
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Gerard Waeber
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Vincent Mooser
- Genetics Division, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Dawn Waterworth
- Genetics Division, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Andrew D. Johnson
- NHLBI's Framingham Heart Study and the Center for Population Studies, Framingham, Massachusetts
| | - Jose C. Florez
- Center for Human Genetic Research and Diabetes Research Center (Diabetes Unit), Massachusetts General Hospital, Boston, Massachusetts, Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachussetts, and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - James B. Meigs
- Department of General Internal Medicine, Massachussetts General Hospital, Boston, Massachusetts
| | - Xiaoning Lu
- Department of Biostatistics, Boston University School of Public Health and NHLBI's Framingham Heart Study, Boston Massachusetts
| | - Stephen T. Turner
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Elizabeth J. Atkinson
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Tennille S. Leak
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Knut Aasarød
- St Olav University Hospital, Trondheim, Norway
- Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Frank Skorpen
- Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Ann-Christine Syvänen
- Molecular Medicine, Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Thomas Illig
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Jens Baumert
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Wolfgang Koenig
- Zentrum für Innere Medizin, Klinik für Innere Medizin II - Kardiologie, Universitätsklinikum Ulm, Ulm, Germany
| | - Bernhard K. Krämer
- University Medical Centre Mannheim, 5th Department of Medicine, Mannheim, Germany
| | - Olivier Devuyst
- NEFR Unit Université Catholique de Louvain Medical School, Brussels, Belgium
| | | | - Cosetta Minelli
- Institute of Genetic Medicine, European Academy of Bolzano/Bozen (EURAC), Italy and Affiliated Institute of the University of Lübeck, Lübeck, Germany
| | - Stephan J.L. Bakker
- Department of Internal Medicine, University Medical Center, Groningen, University of Groningen, Groningen, The Netherlands
| | - Lyudmyla Kedenko
- First Department of Internal Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Bernhard Paulweber
- First Department of Internal Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Stefan Coassin
- Innsbruck Medical University, Division of Genetic Epidemiology, Innsbruck, Austria
| | - Karlhans Endlich
- Institute of Anatomy and Cell Biology, University of Greifswald, Greifswald, Germany
| | - Heyo K. Kroemer
- Institute of Pharmacology, University of Greifswald, Greifswald, Germany
| | - Reiner Biffar
- Clinic for Prosthodontic Dentistry, Gerostomatology and Material Science, University of Greifswald, Greifswald, Germany
| | - Sylvia Stracke
- Nephrology Clinic for Internal Medicine A, University of Greifswald, Greifswald, Germany
| | - Henry Völzke
- Institute for Community Medicine, University of Greifswald, Greifswald, Germany
| | | | - Reedik Mägi
- Wellcome Trust Centre for Human Genetics, and Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom
| | - Harry Campbell
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, Scotland
| | - Veronique Vitart
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland
| | - Nicholas D. Hastie
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland
| | - Vilmundur Gudnason
- University of Iceland, Reykjavik, Iceland
- Icelandic Heart Association, Hjartavernd, Holtasmara, Kopavogur, Iceland
| | - Sharon L.R. Kardia
- University of Michigan School of Public Health, Department of Epidemiology, University of Michigan, Ann Arbor, Michigan
| | - Yongmei Liu
- Department of Biostatistical Sciences, Wake Forest University, Division of Public Health Sciences, Winston-Salem, North Carolina
| | | | - Gary Curhan
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Florian Kronenberg
- Innsbruck Medical University, Division of Genetic Epidemiology, Innsbruck, Austria
| | - Inga Prokopenko
- Wellcome Trust Centre for Human Genetics, and Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom
| | - Igor Rudan
- Center for Population Health Sciences, University of Edinburgh Medical School, Edinburgh, Scotland
| | - Johan Ärnlöv
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Stein Hallan
- St Olav University Hospital, Trondheim, Norway
- Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Gerjan Navis
- Department of Internal Medicine, University Medical Center, Groningen, University of Groningen, Groningen, The Netherlands
| | - the CKDGen Consortium
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
- Department of Epidemiology and the Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland
- Department of Epidemiology and Preventive Medicine, Regensburg University Medical Center, Regensburg, Germany
- Renal Division, University Hospital of Freiburg, Freiburg, Germany
- Division of Nephrology, University of Washington, Seattle, Washington
- Institute of Genetic Medicine, European Academy of Bolzano/Bozen (EURAC), Italy and Affiliated Institute of the University of Lübeck, Lübeck, Germany
- Division of Nephrology, Brigham and Women's Hospital and Harvard Medical School, Boston Massachusetts
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
- Department of Biostatistics, Boston University School of Public Health and NHLBI's Framingham Heart Study, Boston Massachusetts
- Cardiovascular Health Research Unit and Department of Biostatistics, University of Washington, Seattle, Washington
- University of Maryland School of Medicine, Baltimore, Maryland
- Medstar Research Institute, Baltimore, Maryland
- Clinical Research Branch, National Institute on Aging, Baltimore, Maryland
- Division of Nephrology, University of California, San Francisco Medical School and San Francisco VA Medical Center, San Francisco, California
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
- NHLBI's Framingham Heart Study and the Center for Population Studies, Framingham, Massachusetts
- Jackson State University, Jackson, Mississippi
- Loyola University, Maywood, Illinois
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- University of Iceland, Reykjavik, Iceland
- Icelandic Heart Association, Hjartavernd, Holtasmara, Kopavogur, Iceland
- Department of Biostatistical Sciences, Wake Forest University, Division of Public Health Sciences, Winston-Salem, North Carolina
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland
- Innsbruck Medical University, Division of Genetic Epidemiology, Innsbruck, Austria
- Department of Medicine, University of Leipzig, Leipzig, Germany
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Laboratory of Epidemiology, Demography, and Biometry, NIA, Bethesda, Maryland
- University of Maryland School of Medicine, Geriatric Research and Education Clinical Center, Veterans Administration Medical Center, Baltimore, Maryland
- University of Maryland School of Medicine, Baltimore, Maryland
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Human Genetics Center, University of Texas Health Science Center, Houston, Texas
- Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, Maryland
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, Maryland
- University of Pennsylvania Division of Cardiology, Perelman Center for Advanced Medicine, Philadelphia, Pennsylvania
- University of Pennsylvania Renal Electrolyte and Hypertension Division, Philadelphia, Pennsylvania
- Departments of Epidemiology and Medicine, University of Washington, Seattle, Washington
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology, and Health Services and Group Health Research Institute, Group Health Cooperative, Seattle, Washington
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Genetics Division, GlaxoSmithKline, King of Prussia, Pennsylvania
- Center for Human Genetic Research and Diabetes Research Center (Diabetes Unit), Massachusetts General Hospital, Boston, Massachusetts, Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachussetts, and Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Department of General Internal Medicine, Massachussetts General Hospital, Boston, Massachusetts
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
- St Olav University Hospital, Trondheim, Norway
- Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Molecular Medicine, Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Zentrum für Innere Medizin, Klinik für Innere Medizin II - Kardiologie, Universitätsklinikum Ulm, Ulm, Germany
- University Medical Centre Mannheim, 5th Department of Medicine, Mannheim, Germany
- NEFR Unit Université Catholique de Louvain Medical School, Brussels, Belgium
- Center for Public Health Genomics, Charlottesville, Virginia
- Department of Internal Medicine, University Medical Center, Groningen, University of Groningen, Groningen, The Netherlands
- First Department of Internal Medicine, Paracelsus Medical University, Salzburg, Austria
- Institute of Anatomy and Cell Biology, University of Greifswald, Greifswald, Germany
- Institute of Pharmacology, University of Greifswald, Greifswald, Germany
- Clinic for Prosthodontic Dentistry, Gerostomatology and Material Science, University of Greifswald, Greifswald, Germany
- Nephrology Clinic for Internal Medicine A, University of Greifswald, Greifswald, Germany
- Institute for Community Medicine, University of Greifswald, Greifswald, Germany
- Wellcome Trust Centre for Human Genetics, and Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, Scotland
- University of Michigan School of Public Health, Department of Epidemiology, University of Michigan, Ann Arbor, Michigan
- Gen-Info Ltd., Zagreb, Croatia
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Center for Population Health Sciences, University of Edinburgh Medical School, Edinburgh, Scotland
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
- University of Maryland School of Medicine, Baltimore, Maryland
- Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, Maryland
- General Internal Medicine, University of California, San Francisco, San Francisco, California
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Prosserman Centre for Health Research, Toronto, Ontario, Canada
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
- Klinikum Grosshadern, Munich, Germany
- Service of Medical Genetics, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts
- Institute of Physiology, University of Greifswald, Greifswald, Germany
- University of Mississippi Division of Nephrology, University of Mississippi, Jackson, Mississippi
- University Institute of Social and Preventive Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, IUMSP, Lausanne, Switzerland; and
- Division of Endocrinology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Afshin Parsa
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Luigi Ferrucci
- Clinical Research Branch, National Institute on Aging, Baltimore, Maryland
| | - Josef Coresh
- Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, Maryland
| | - Michael G. Shlipak
- General Internal Medicine, University of California, San Francisco, San Francisco, California
| | - Shelley B. Bull
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Prosserman Centre for Health Research, Toronto, Ontario, Canada
| | | | - on behalf of DCCT/EDIC
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
- Department of Epidemiology and the Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland
- Department of Epidemiology and Preventive Medicine, Regensburg University Medical Center, Regensburg, Germany
- Renal Division, University Hospital of Freiburg, Freiburg, Germany
- Division of Nephrology, University of Washington, Seattle, Washington
- Institute of Genetic Medicine, European Academy of Bolzano/Bozen (EURAC), Italy and Affiliated Institute of the University of Lübeck, Lübeck, Germany
- Division of Nephrology, Brigham and Women's Hospital and Harvard Medical School, Boston Massachusetts
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
- Department of Biostatistics, Boston University School of Public Health and NHLBI's Framingham Heart Study, Boston Massachusetts
- Cardiovascular Health Research Unit and Department of Biostatistics, University of Washington, Seattle, Washington
- University of Maryland School of Medicine, Baltimore, Maryland
- Medstar Research Institute, Baltimore, Maryland
- Clinical Research Branch, National Institute on Aging, Baltimore, Maryland
- Division of Nephrology, University of California, San Francisco Medical School and San Francisco VA Medical Center, San Francisco, California
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
- NHLBI's Framingham Heart Study and the Center for Population Studies, Framingham, Massachusetts
- Jackson State University, Jackson, Mississippi
- Loyola University, Maywood, Illinois
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- University of Iceland, Reykjavik, Iceland
- Icelandic Heart Association, Hjartavernd, Holtasmara, Kopavogur, Iceland
- Department of Biostatistical Sciences, Wake Forest University, Division of Public Health Sciences, Winston-Salem, North Carolina
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Road, Edinburgh, Scotland
- Innsbruck Medical University, Division of Genetic Epidemiology, Innsbruck, Austria
- Department of Medicine, University of Leipzig, Leipzig, Germany
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Laboratory of Epidemiology, Demography, and Biometry, NIA, Bethesda, Maryland
- University of Maryland School of Medicine, Geriatric Research and Education Clinical Center, Veterans Administration Medical Center, Baltimore, Maryland
- University of Maryland School of Medicine, Baltimore, Maryland
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Human Genetics Center, University of Texas Health Science Center, Houston, Texas
- Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, Maryland
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, Maryland
- University of Pennsylvania Division of Cardiology, Perelman Center for Advanced Medicine, Philadelphia, Pennsylvania
- University of Pennsylvania Renal Electrolyte and Hypertension Division, Philadelphia, Pennsylvania
- Departments of Epidemiology and Medicine, University of Washington, Seattle, Washington
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology, and Health Services and Group Health Research Institute, Group Health Cooperative, Seattle, Washington
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Genetics Division, GlaxoSmithKline, King of Prussia, Pennsylvania
- Center for Human Genetic Research and Diabetes Research Center (Diabetes Unit), Massachusetts General Hospital, Boston, Massachusetts, Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachussetts, and Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Department of General Internal Medicine, Massachussetts General Hospital, Boston, Massachusetts
- Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
- St Olav University Hospital, Trondheim, Norway
- Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Molecular Medicine, Department of Medical Sciences, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Zentrum für Innere Medizin, Klinik für Innere Medizin II - Kardiologie, Universitätsklinikum Ulm, Ulm, Germany
- University Medical Centre Mannheim, 5th Department of Medicine, Mannheim, Germany
- NEFR Unit Université Catholique de Louvain Medical School, Brussels, Belgium
- Center for Public Health Genomics, Charlottesville, Virginia
- Department of Internal Medicine, University Medical Center, Groningen, University of Groningen, Groningen, The Netherlands
- First Department of Internal Medicine, Paracelsus Medical University, Salzburg, Austria
- Institute of Anatomy and Cell Biology, University of Greifswald, Greifswald, Germany
- Institute of Pharmacology, University of Greifswald, Greifswald, Germany
- Clinic for Prosthodontic Dentistry, Gerostomatology and Material Science, University of Greifswald, Greifswald, Germany
- Nephrology Clinic for Internal Medicine A, University of Greifswald, Greifswald, Germany
- Institute for Community Medicine, University of Greifswald, Greifswald, Germany
- Wellcome Trust Centre for Human Genetics, and Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, Scotland
- University of Michigan School of Public Health, Department of Epidemiology, University of Michigan, Ann Arbor, Michigan
- Gen-Info Ltd., Zagreb, Croatia
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Center for Population Health Sciences, University of Edinburgh Medical School, Edinburgh, Scotland
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
- University of Maryland School of Medicine, Baltimore, Maryland
- Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, Maryland
- General Internal Medicine, University of California, San Francisco, San Francisco, California
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Prosserman Centre for Health Research, Toronto, Ontario, Canada
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
- Klinikum Grosshadern, Munich, Germany
- Service of Medical Genetics, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts
- Institute of Physiology, University of Greifswald, Greifswald, Germany
- University of Mississippi Division of Nephrology, University of Mississippi, Jackson, Mississippi
- University Institute of Social and Preventive Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, IUMSP, Lausanne, Switzerland; and
- Division of Endocrinology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - H.-Erich Wichmann
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
- Klinikum Grosshadern, Munich, Germany
| | - Nicholas J. Wareham
- MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Ruth J.F. Loos
- MRC Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Jerome I. Rotter
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Peter P. Pramstaller
- Institute of Genetic Medicine, European Academy of Bolzano/Bozen (EURAC), Italy and Affiliated Institute of the University of Lübeck, Lübeck, Germany
| | - L. Adrienne Cupples
- Department of Biostatistics, Boston University School of Public Health and NHLBI's Framingham Heart Study, Boston Massachusetts
| | - Jacques S. Beckmann
- Service of Medical Genetics, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Qiong Yang
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts
| | - Iris M. Heid
- Department of Epidemiology and Preventive Medicine, Regensburg University Medical Center, Regensburg, Germany
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Rainer Rettig
- Institute of Physiology, University of Greifswald, Greifswald, Germany
| | - Albert W. Dreisbach
- University of Mississippi Division of Nephrology, University of Mississippi, Jackson, Mississippi
| | - Murielle Bochud
- University Institute of Social and Preventive Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, IUMSP, Lausanne, Switzerland; and
| | - Caroline S. Fox
- NHLBI's Framingham Heart Study and the Center for Population Studies, Framingham, Massachusetts
- Division of Endocrinology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - W.H.L. Kao
- Department of Epidemiology and the Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, Maryland
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Reich HN, Tritchler D, Cattran DC, Herzenberg AM, Eichinger F, Boucherot A, Henger A, Berthier CC, Nair V, Cohen CD, Scholey JW, Kretzler M. A molecular signature of proteinuria in glomerulonephritis. PLoS One 2010; 5:e13451. [PMID: 20976140 PMCID: PMC2956647 DOI: 10.1371/journal.pone.0013451] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 09/17/2010] [Indexed: 01/13/2023] Open
Abstract
Proteinuria is the most important predictor of outcome in glomerulonephritis and experimental data suggest that the tubular cell response to proteinuria is an important determinant of progressive fibrosis in the kidney. However, it is unclear whether proteinuria is a marker of disease severity or has a direct effect on tubular cells in the kidneys of patients with glomerulonephritis. Accordingly we studied an in vitro model of proteinuria, and identified 231 “albumin-regulated genes” differentially expressed by primary human kidney tubular epithelial cells exposed to albumin. We translated these findings to human disease by studying mRNA levels of these genes in the tubulo-interstitial compartment of kidney biopsies from patients with IgA nephropathy using microarrays. Biopsies from patients with IgAN (n = 25) could be distinguished from those of control subjects (n = 6) based solely upon the expression of these 231 “albumin-regulated genes.” The expression of an 11-transcript subset related to the degree of proteinuria, and this 11-mRNA subset was also sufficient to distinguish biopsies of subjects with IgAN from control biopsies. We tested if these findings could be extrapolated to other proteinuric diseases beyond IgAN and found that all forms of primary glomerulonephritis (n = 33) can be distinguished from controls (n = 21) based solely on the expression levels of these 11 genes derived from our in vitro proteinuria model. Pathway analysis suggests common regulatory elements shared by these 11 transcripts. In conclusion, we have identified an albumin-regulated 11-gene signature shared between all forms of primary glomerulonephritis. Our findings support the hypothesis that albuminuria may directly promote injury in the tubulo-interstitial compartment of the kidney in patients with glomerulonephritis.
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Affiliation(s)
- Heather N Reich
- Division of Nephrology, University Health Network, University of Toronto, Toronto, Ontario, Canada.
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Li Y, Liu FY, Peng YM, Li J, Sun L, Chen X, Duan SB, Ling GH, Guo N, Liu YH. The relationship between the TGF-beta1 gene -509C/T polymorphism and tubulointerstitial damage resulting from primary nephrotic syndrome. Ren Fail 2010; 32:420-7. [PMID: 20446778 DOI: 10.3109/08860221003646337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The aim of this study was to investigate the correlation between the transforming growth factor (TGF)-beta1 gene -509C/T polymorphism and the susceptibility to primary nephrotic syndrome (PNS), and in particular to the severe degree of tubulointerstitial damage (TID) seen in Chinese. METHODS Ninety-eight PNS patients and 128 normal controls were studied. The extent of tubulointerstitial changes was evaluated and patients were divided into two groups according to the severe or mild degree of TID. The TGF-beta1gene -509C/T polymorphism was detected with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, and the serum level of TGF-beta1 was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS No statistical differences in genotype or allele frequency of the TGF-beta1 gene -509C/T were found between PNS and normal subjects. However, T allele and CT + T T genotype frequency were higher in the PNS with severe TID than the mild TID and controls. Additionally, the serum concentration of TGF-beta1 was significantly higher in the PNS with severe TID group than the other two groups and in the T T genotype individuals than the CC and CT genotype individuals. A logistic regression analysis demonstrated that TGF-beta1 gene -509C/T genotype was the risk factor of TID in PNS patients [OR (odd ratio) 2.34, confidence interval (CI) 0.98-3.46, p = 0.012]. CONCLUSION. TGF-beta1 gene -509C/T polymorphism was associated with severe TID. The higher value in serum concentration of TGF-beta1 was also associated with severe TID and the T T genotype/T allele. T allele gene might be the important risk factor for susceptibility.
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Affiliation(s)
- Y Li
- Division of Nephrology, The Second Xiangya Hospital, Research Institute of Nephrology, Central-South University and The Key Laboratory of Nephrology and Blood Purification in Hunan, Changsha 410011, Hunan Province, PR China.
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Shui H, Gao P, Si X, Ding G. Mycophenolic acid inhibits albumin-induced MCP-1 expression in renal tubular epithelial cells through the p38 MAPK pathway. Mol Biol Rep 2009; 37:1749-54. [DOI: 10.1007/s11033-009-9599-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 06/22/2009] [Indexed: 10/20/2022]
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36
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van Timmeren MM, Gross ML, Hanke W, Klok PA, van Goor H, Stegeman CA, Bakker SJL. Oleic acid loading does not add to the nephrotoxic effect of albumin in an amphibian and chronic rat model of kidney injury. Nephrol Dial Transplant 2008; 23:3814-23. [DOI: 10.1093/ndt/gfn417] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Ferraccioli G, Romano G. Renal interstitial cells, proteinuria and progression of lupus nephritis: new frontiers for old factors. Lupus 2008; 17:533-40. [DOI: 10.1177/0961203307088002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Interstitial cells, inflammatory-immune cells, tubular cells and endothelial cells of the peritubular capillaries have arisen as possible major players of the nephron damage in lupus nephritis. Increased ICAM-1, Von Willebrand factor, soluble endothelial protein C receptors and decreased ADAMS-13 point to a diffuse vascular damage. Albuminuria elicits a rapid generation of hydrogen peroxide in proximal tubular cells along with nuclear factor-kB activation, endothelin-1 and transforming growth factor (TGF-β1) upregulation. TGF-β1 enhances epithelial-to-mesenchymal transdifferentiation. Albuminuria also enhances the expression of macrophage chemotactic protein-1 and macrophage inflammatory protein-1α, thus leading to increased interstitial inflammation. TGF-β1 and thrombospondin-1, a putative activator of TGF-β, induce apoptosis of peritubular capillaries, as well as of glomerular endothelial cells. All these events can be counteracted by hepatocyte growth factor (HGF), which is expressed by the epithelial tubular cells and stimulates the growth of epithelial cells (mitogen), enhances the motility of epithelial cells (motogen), induces renal epithelial tubule regeneration (morphogen) and enhances angiogenesis (angiogen). The balance between TGF-β1 and HGF could be a key to define the prognostic value of kidney histopathology at baseline and during follow-up, in lupus nephritis. Therapeutic strategies aiming at altering the biological balance in the patients are at hand to test and prove the experimental evidences.
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Affiliation(s)
- G Ferraccioli
- Division of Rheumatology, Catholic University of the Sacred Heart, Rome, Italy
| | - G Romano
- Nephrology Unit, University of Udine, Udine, Italy
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Li M, Balamuthusamy S, Simon EE, Batuman V. Silencing megalin and cubilin genes inhibits myeloma light chain endocytosis and ameliorates toxicity in human renal proximal tubule epithelial cells. Am J Physiol Renal Physiol 2008; 295:F82-90. [PMID: 18448595 DOI: 10.1152/ajprenal.00091.2008] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Using target-specific short interfering (si) RNAs, we silenced the tandem endocytic receptors megalin and cubilin genes in cultured human renal proximal tubule epithelial cells. Transfection by siRNA resulted in up to 90% suppression of both megalin and cubilin protein and mRNA expression. In HK-2 cells exposed to kappa-light chain for up to 24 h, light chain endocytosis was reduced in either megalin- or cubilin-silenced cells markedly but incompletely. Simultaneous silencing of both the cubilin and megalin genes, however, resulted in near-complete inhibition of light chain endocytosis, as determined by measuring kappa-light chain protein concentration in cell cytoplasm and by flow cytometry using FITC-labeled kappa-light chain. In these cells, light chain-induced cytokine responses (interleukin-6 and monocyte chemoattractant protein-1) and epithelial-to-mesenchymal transition as well as the associated cellular and morphological alterations were also markedly suppressed. The results demonstrate that light chain endocytosis is predominantly mediated by the megalin-cubilin tandem endocytic receptor and identify endocytosis as a key step in light chain cytotoxicity. Blocking light chain endocytosis prevents its nephrotoxic effects on human kidney proximal tubule cells.
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Affiliation(s)
- Min Li
- Section of Nephrology and Hypertension, Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112-2632, USA
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Kelly KJ, Wu P, Patterson CE, Temm C, Dominguez JH. LOX-1 and inflammation: a new mechanism for renal injury in obesity and diabetes. Am J Physiol Renal Physiol 2008; 294:F1136-45. [PMID: 18322020 DOI: 10.1152/ajprenal.00396.2007] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The early nephropathy in obese, diabetic, dyslipidemic (ZS) rats is characterized by tubular lipid accumulation and pervasive inflammation, two critically interrelated events. We now tested the hypothesis that proximal tubules from ZS obese diabetic rats in vivo, and proximal tubule cells (NRK52E) exposed to oxidized LDL (oxLDL) in vitro, change their normally quiescent epithelial phenotype into a proinflammatory phenotype. Urine of obese diabetic rats contained more lipid peroxides, and LOX-1, a membrane receptor that internalizes oxidized lipids, was mobilized to luminal sites. Levels of ICAM-1 and focal adhesion kinase, which participate in leukocyte migration and epithelial dedifferentiation, respectively, were also upregulated in tubules. NRK52E cells exposed to oxLDL showed similar modifications, plus suppression of anti-inflammatory transcription factor peroxisome proliferator-activated receptor-delta. In addition, oxLDL impaired epithelial barrier function. These alterations were prevented by an anti-LOX-1 antibody. The data support the concept that tubular LOX-1 activation driven by lipid oxidants in the preurine fluid is critical in the inflammatory changes. We suggest that luminal lipid oxidants and abnormal tubular permeability may be partly responsible for the renal tubulointerstitial injury of obesity, diabetes, and dyslipidemia.
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Affiliation(s)
- Katherine J Kelly
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Diwakar R, Pearson AL, Colville-Nash P, Baines DL, Dockrell MEC. Role played by disabled-2 in albumin induced MAP Kinase signalling. Biochem Biophys Res Commun 2007; 366:675-80. [PMID: 18070591 DOI: 10.1016/j.bbrc.2007.11.171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Accepted: 11/27/2007] [Indexed: 10/22/2022]
Abstract
Albumin has been shown to activate the mitogen activated protein kinase (MAPK) pathway in proximal tubular cells (PTECs) of the kidney. Megalin, the putative receptor for albumin has potential signalling properties. However, the mechanisms by which megalin signals are unclear. The adaptor phosphoprotein Disabled-2 (Dab2) is known to interact with the cytoplasmic tail of megalin and may be involved in albumin-mediated MAPK signalling. In this study, we investigated the role of Dab2 in albumin-mediated MAPK signalling and further studied the role of Dab2 in albumin-induced TGFbeta-1 secretion, a MAPK dependent event. We used RNA interference to knockdown Dab2 protein abundance in HKC-8 cells a model of human PTECs. Albumin activated ERK1,2 and Elk-1 in a MEK-1 dependent manner and resulted in secretion of TGFbeta-1. In the absence of albumin, knockdown of Dab2 resulted in a trend towards increase in pERK1,2 consistent with its putative role as an inhibitor of cell proliferation. However albumin-induced ERK1,2 activation was completely abolished by Dab2 knockdown. Dab2 knockdown did not however result in inhibition of albumin-induced TGFbeta-1 secretion. These results suggest that Dab2 is a ligand dependent bi-directional regulator of ERK1,2 activity by demonstrating that in addition to its more traditional role as an inhibitor of ERK1,2 it may also activate ERK1,2.
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Affiliation(s)
- Ramaswamy Diwakar
- South West Thames Institute for Renal Research, St. Helier Hospital, Wrythe Lane, Carshalton, Surrey SM5 1AA, UK
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Wei J, Ma C, Li YM. Combined effect of pioglitazone and simvastatin on urinary liver-type fatty acid-binding protein concentration in diabetic patients with microalbuminuria. Diabetologia 2007. [PMID: 17520237 DOI: 10.1007/s00125-007-0703-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 04/03/2007] [Indexed: 11/30/2022]
Affiliation(s)
- J Wei
- Department of Nephrology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People’s Republic of China
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