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Ma J, Ma R, Zhao X, Wang Y, Liao S, Nong C, Lu F, Liang Z, Huang J, Huang Y, Zhu Z, Wang J. Cyr61 Mediates Angiotensin II-Induced Podocyte Apoptosis via the Upregulation of TXNIP. J Immunol Res 2023; 2023:8643548. [PMID: 37032654 PMCID: PMC10076116 DOI: 10.1155/2023/8643548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/02/2022] [Indexed: 03/31/2023] Open
Abstract
Purpose. It is well documented that angiotensin II (Ang II) elevation promotes apoptosis of podocytes in vivo and vitro, but the potential mechanism is still oscular. The current study is aimed at probing into the assignment of cysteine-rich protein 61 (Cyr61) in Ang II-induced podocyte apoptosis. Methods. Podocytes were treated with Ang II (10-6 mol/L) for 48 hours to establish an injury model in vitro. Western blot assays were detected the expression of Cyr61, Cyt-c, Bax, and Bcl-2. Gene microarray was used to analyze the expression of mRNAs after treatment with Ang II. CRISPR/Cas9 technology was used to knock down Cyr61 and overexpress TXNIP gene, respectively. Results. The expression of Cyr61, TXNIP, Cyt-c, and Bax in podocytes treated with Ang II were upregulated, but the expression and apoptotic rates of Bcl-2 in podocytes were inhibited. The level of the above factors was not significantly different after the knockdown of Cyr61 with Ang II in podocytes. In Ang II group, when knocked down Cyr61, the expressed level of TXNIP, Cyt-c, and Bax was diminished after Ang II treatment; interestingly Bcl-2 expression and podocyte apoptotic rate were reduced. Under the stimulation of Ang II, the expression of Cyt-c and Bax were growing, whereas Bcl-2 was reduced, and the apoptotic rates were higher in the TXNIP overexpression group. Cyt-c and Bax were put on, whereas that of Bcl-2 was to be cut down when the Cyr61 was knockdown, and the apoptotic rates were gained in the TXNIP overexpression+Cyr61 knockdown group. Conclusions. The results of the study extrapolate that Cyr61 plays a dominant role in Ang II-induced podocyte apoptosis. Additionally, Cyr61 may mediate the Ang II-induced podocyte apoptosis by promoting the expression of TNXIP.
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Martins ALMDS, Bernardes AB, Ferreira VA, Wanderley DC, Araújo SDA, do Carmo Neto JR, da Silva CA, Lira RCP, Araújo LS, Dos Reis MA, Machado JR. In situ assessment of Mindin as a biomarker of podocyte lesions in diabetic nephropathy. PLoS One 2023; 18:e0284789. [PMID: 37130106 PMCID: PMC10153717 DOI: 10.1371/journal.pone.0284789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 04/07/2023] [Indexed: 05/03/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of chronic kidney disease and end-stage renal failure worldwide. Several mechanisms are involved in the pathogenesis of this disease, which culminate in morphological changes such as podocyte injury. Despite the complex diagnosis and pathogenesis, limited attempts have been made to establish new biomarkers for DN. The higher concentration of Mindin protein in the urine of patients with type 2 diabetes mellitus suggests that it plays a role in DN. Therefore, this study investigated whether in situ protein expression of Mindin can be considered a potential DN biomarker. Fifty renal biopsies from patients diagnosed with DN, 57 with nondiabetic glomerular diseases, including 17 with focal segmental glomerulosclerosis (FSGS), 14 with minimal lesion disease (MLD) and 27 with immunoglobulin A nephropathy (IgAN), and 23 adult kidney samples from autopsies (control group) were evaluated for Mindin expression by immunohistochemistry. Podocyte density was inferred by Wilms' tumor 1 (WT1) immunostaining, while foot process effacement was assessed by transmission electron microscopy. Receiver operative characteristic (ROC) analysis was performed to determine the biomarker sensitivity/specificity. Low podocyte density and increased Mindin expression were observed in all cases of DN, regardless of their class. In the DN group, Mindin expression was significantly higher than that in the FSGS, MCD, IgAN and control groups. Higher Mindin expression was significantly positively correlated with foot process effacement only in class III DN cases. Furthermore, Mindin protein presented high specificity in the biopsies of patients with DN (p < 0.0001). Our data suggest that Mindin may play a role in DN pathogenesis and is a promising biomarker of podocyte lesions.
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Affiliation(s)
- Ana Luisa Monteiro Dos Santos Martins
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Alexia Borges Bernardes
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Verônica Aparecida Ferreira
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - David Campos Wanderley
- Institute of Nephropathology, Center for Electron Microscopy, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Stanley de Almeida Araújo
- Institute of Nephropathology, Center for Electron Microscopy, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - José Rodrigues do Carmo Neto
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiania, Goiás, Brazil
| | - Crislaine Aparecida da Silva
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Régia Caroline Peixoto Lira
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Liliane Silvano Araújo
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Marlene Antônia Dos Reis
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Juliana Reis Machado
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
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Zhao YL, Zhang XH, Guo F, Wei Y, Shang JH, Luo XD. Yi Shen An, a Chinese traditional prescription, ameliorates membranous glomerulonephritis induced by cationic bovine serum albumin in rats. PHARMACEUTICAL BIOLOGY 2022; 60:163-174. [PMID: 35001799 PMCID: PMC8745358 DOI: 10.1080/13880209.2021.2021947] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/15/2021] [Accepted: 12/19/2021] [Indexed: 06/14/2023]
Abstract
CONTEXT Yi Shen An (YSA) is an investigational composite of traditional Chinese medicine (Reference: 2010L000974) for the treatment of renal disease. OBJECTIVE To investigate the protective effects of YSA against membranous glomerulonephritis (MGN). MATERIALS AND METHODS Male Sprague-Dawley rats were injected with cationic bovine serum albumin (C-BSA) to create a model of MGN. Then, rats were orally treated with YSA at doses of 0.25, 0.5, 1 and 2 g/kg for 35 successive days; prednisone (5 mg/kg) was used as a positive control. At the end of the experimental period, we performed a series of tests, including 24 h urinary protein, and biochemical, immunological, antioxidative, coagulation indices, and histopathological examination. RESULTS YSA-1 g/kg significantly lowered urinary protein from 68.37 to 30.74 mg (p < 0.01). Meantime, total protein (TP) and albumin (ALB) recovered from 66.26 and 20.51 g/L to 76.08 and 35.64 g/L (p < 0.01), respectively. YSA removed the deposition of immunoglobulin G (IgG) and complement 3c (C3c), prevented inter-capillary cell hyperplasia on the glomerular basement membrane (GBM), and reduced electron-dense deposits and fusion of podocytes. In addition, serum IgG and superoxide dismutase were significantly elevated. In contrast, malondialdehyde, total cholesterol, triglyceride, circulating immune complex (CIC), and immunoglobulin M decreased in the YSA-treated group. Moreover, the blood coagulation dysfunction was adjusted. DISCUSSION AND CONCLUSIONS These findings indicate YSA may exert a therapeutic effect against MGN through the inhibition of CIC formation, and the removal of IgG and C3c deposition from the GBM, thus supporting the development of further clinical trials.
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Affiliation(s)
- Yun-Li Zhao
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Chemical Science and Technology, Yunnan University, Kunming, P. R. China
| | - Xiang-Hua Zhang
- New Drug R&D Department of Kunming Institute of Kidney Disease, Kunming, P. R. China
| | - Feng Guo
- New Drug R&D Department of Kunming Institute of Kidney Disease, Kunming, P. R. China
| | - Ying Wei
- Shang Hai University of Medicine & Health Sciences, Shang Hai, P. R. China
| | - Jian-Hua Shang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, P. R. China
| | - Xiao-Dong Luo
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Chemical Science and Technology, Yunnan University, Kunming, P. R. China
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, P. R. China
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Yu S, Ren Q, Chen J, Huang J, Liang R. Rapamycin reduces podocyte damage by inhibiting the PI3K/AKT/mTOR signaling pathway and promoting autophagy. EUR J INFLAMM 2022. [DOI: 10.1177/1721727x221081732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: Rapamycin is a potent inducer of autophagy in podocytes. However, we still understand very little about how autophagy is regulated under podocyte injury conditions. This study aimed to investigate the role of autophagy in podocyte injury and the regulatory mechanism of the PI3K/Akt/mTOR signaling pathway in this process. Methods: The podocytes were cultured in vitro, and the apoptosis rate of each group was determined by flow cytometry. The protein expression and distribution of LC3-II were examined by immunofluorescence. The phosphorylation levels of Akt, LC3-II, mTOR, 4EBP1, and P70S6K were measured using Western Blot. Transmission electron microscopy was used to examine the changes in autophagosomes in each group. Results: Compared with the control group, the puromycin group (PAN) increased podocyte apoptosis, decreased numbers of autophagosomes, and downregulated LC3-II protein expression. Compared with the PAN group, the podocyte apoptosis rate decreased in the Rapamycin group (RAPA), the number of autophagosomes increased, and LC3-II protein expression was upregulated. In addition, PAN evoked an increase in p-Akt expressions, RAPA treatment induced a reversal of PAN-induced p-Akt upregulation, and the phosphorylation levels of mTOR, 4EBP1, and P70S6K were downregulated. Conclusion: PAN can damage podocytes by inhibiting podocyte autophagic activity and promoting apoptosis. Rapamycin can ameliorate PAN-induced podocyte damage by activating autophagy. This effect may be related to rapamycin-mediated PI3K/AKT/mTOR signaling pathway and autophagy.
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Affiliation(s)
- Shengyou Yu
- Department of Pediatrics, Guangzhou First People’s Hospital, School of Medicine, South China University of Technology, GuangZhou, GuangDong, China
| | - Qi Ren
- Guangzhou Women and Children’s Medical Center, GuangZhou, GuangDong, P.R.China
| | - Jing Chen
- Department of Image, The University of Hong Kong-Shenzhen Hospital, Shenzhen, GuangDong, China
| | - Jing Huang
- Department of Pediatrics, The University of Hong Kong-Shenzhen Hospital, Shenzhen, GuangDong, China
| | - Rui Liang
- Department of Pediatrics, The University of Hong Kong-Shenzhen Hospital, Shenzhen, GuangDong, China
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Cutrim ÉMM, Neves PDMDM, Campos MAG, Wanderley DC, Teixeira-Júnior AAL, Muniz MPR, Ladchumananandasivam FR, Gomes OV, Vasco RFV, Brito DJDA, Lages JS, Salgado-Filho N, Guedes FL, de Almeida JB, Magalhães M, Araújo SDA, Silva GEB. Collapsing Glomerulopathy: A Review by the Collapsing Brazilian Consortium. Front Med (Lausanne) 2022; 9:846173. [PMID: 35308512 PMCID: PMC8927620 DOI: 10.3389/fmed.2022.846173] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/08/2022] [Indexed: 01/10/2023] Open
Abstract
Collapsing glomerulopathy (CG) is a clinicopathologic entity characterized by segmentar or global collapse of the glomerulus and hypertrophy and hyperplasia of podocytes. The Columbia classification of 2004 classified CG as a histological subtype of focal segmental glomerulosclerosis (FSGS). A growing number of studies have demonstrated a high prevalence of CG in many countries, especially among populations with a higher proportion of people with African descent. The present study is a narrative review of articles extracted from PubMed, Medline, and Scielo databases from September 1, 2020 to December 31, 2021. We have focused on populational studies (specially cross-sectional and cohort articles). CG is defined as a podocytopathy with a distinct pathogenesis characterized by strong podocyte proliferative activity. The most significant risk factors for CG include APOL1 gene mutations and infections with human immunodeficiency virus and severe acute respiratory syndrome coronavirus 2. CG typically presents with more severe symptoms and greater renal damage. The prognosis is notably worse than that of other FSGS subtypes.
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Affiliation(s)
| | | | | | - Davi Campos Wanderley
- Nephropathology Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | - Orlando Vieira Gomes
- University Hospital, Federal University of Vale do São Francisco, Petrolina, Brazil
| | | | | | | | | | - Felipe Leite Guedes
- University Hospital, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | - Marcelo Magalhães
- Laboratory of Genomic and Histocompatibility Studies, University Hospital, Federal University of Maranhão, São Luís, Brazil
| | | | - Gyl Eanes Barros Silva
- University Hospital, Federal University of Maranhão, São Luís, Brazil
- *Correspondence: Gyl Eanes Barros Silva,
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Song H, Zhuang L, Xu X, Shi J, Hu W, Liu Z, Shi S. MCC Regulator of WNT Signaling Pathway (MCC) Is a Podocyte Essential Gene. Front Med (Lausanne) 2021; 8:777563. [PMID: 34926519 PMCID: PMC8674659 DOI: 10.3389/fmed.2021.777563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/11/2021] [Indexed: 12/13/2022] Open
Abstract
Podocytes are an integral part of the glomerular filtration barrier. Many genes are already known to be essential for podocyte survival, structure and function, but there are more podocyte essential genes to be identified. By single-cell RNA-seq of mouse podocytes, we detected the expression of gene encoding MCC regulator of WNT signaling pathway (MCC) in majority of the podocytes and speculated that MCC is essential for podocytes. We confirmed MCC expression in mouse podocytes and further showed its expression in human podocytes. To experimentally prove the essentiality of MCC for podocytes, we knocked down MCC in cultured podocytes and found marked morphological change of cell shape, cytoskeletal F-actin stress fiber disruption, increased apoptosis, and downregulation of podocyte essential genes, CD2AP and WT1, demonstrating that MCC is essential for podocytes. Since MCC has been implicated in cell cycle and β-catenin signaling, we examined the expression of cell cycle related genes and activity of β-catenin in the MCC knockdown podocytes, but did not find significant changes. To further explore the mechanism underlying the role of MCC in podocytes, we performed RNA-sequencing and bioinformatics analysis of MCC knockdown podocytes and found a significant enrichment of the regulated genes in lamellipodia formation. Consistently, we found that MCC is present in lamellipodia and MCC knockdown resulted in loss of lamellipodia in the cells. Lastly, we found that MCC was downregulated in podocytes treated with puromycin aminonucleosides and in glomeruli of diabetic mice and FSGS patients, implicating MCC is involved in the development of podocytopathy and proteinuria. In conclusion, MCC is potentially essential for podocytes and its downregulation may be involved in podocytopathy.
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Affiliation(s)
- Hui Song
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Lulu Zhuang
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xiaodong Xu
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jingsong Shi
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Weixin Hu
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhihong Liu
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Shaolin Shi
- National Clinical Research Center for Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
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7
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Hill N, Michell DL, Ramirez-Solano M, Sheng Q, Pusey C, Vickers KC, Woollard KJ. Glomerular endothelial derived vesicles mediate podocyte dysfunction: A potential role for miRNA. PLoS One 2020; 15:e0224852. [PMID: 32214346 PMCID: PMC7098579 DOI: 10.1371/journal.pone.0224852] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 02/26/2020] [Indexed: 12/28/2022] Open
Abstract
MicroRNAs (miRNA) are shown to be involved in the progression of several types of kidney diseases. Podocytes maintain the integrity of the glomerular basement membrane. Extracellular vesicles (EV) are important in cell-to-cell communication as they can transfer cellular content between cells, including miRNA. However, little is known about how extracellular signals from the glomerular microenvironment regulate podocyte activity. Using a non-contact transwell system, communication between glomerular endothelial cells (GEnC) and podocytes was characterised in-vitro. Identification of transferred EV-miRNAs from GEnC to podocytes was performed using fluorescence cell tracking and miRNA mimetics. To represent kidney disease, podocyte molecular profiling and functions were analysed after EV treatments derived from steady state or activated GEnC. Our data shows activation of GEnC alters EV-miRNA loading, but activation was not found to alter EV secretion. EV delivery of miRNA to recipient podocytes altered cellular miRNA abundance and effector functions in podocytes, including decreased secretion of VEGF and increased mitochondrial stress which lead to altered cellular metabolism and cytoskeletal rearrangement. Finally, results support our hypothesis that miRNA-200c-3p is transfered by EVs from GEnC to podocytes in response to activation, ultimately leading to podocyte dysfunction.
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Affiliation(s)
- N. Hill
- Department of Medicine, Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
| | - D. L. Michell
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - M. Ramirez-Solano
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Q. Sheng
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - C. Pusey
- Department of Medicine, Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
| | - K. C. Vickers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - K. J. Woollard
- Department of Medicine, Centre for Inflammatory Disease, Imperial College London, London, United Kingdom
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Evaluation of the Diagnostic Potential of uPAR as a Biomarker in Renal Biopsies of Patients with FSGS. DISEASE MARKERS 2019; 2019:1070495. [PMID: 31191741 PMCID: PMC6525920 DOI: 10.1155/2019/1070495] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/12/2019] [Accepted: 03/05/2019] [Indexed: 02/06/2023]
Abstract
Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are primary glomerulopathies leading to proteinuria, known as podocytopathies, which share syndromic and morphological similarities. Morphological similarity occurs in cases of FSGS in which the sclerotic lesion was not sampled in renal biopsy, due to the focal nature of the disease. Differentiating these entities is very important, especially in cases of suspected FSGS but with sclerotic lesion not sampled, as they are diseases that apparently have different pathogenic mechanisms and prognosis. The difference in uPAR expression in situ among these two entities may be related to a distinct molecular mechanism involved in pathogenesis. Thus, finding biomarkers involved in the pathogenesis and that can also help in differential diagnosis is very relevant. The aim of this work was to evaluate the potential of urokinase-type plasminogen activator receptor (uPAR) as a biomarker in renal biopsies of patients with podocytopathies (n = 38). Immunohistochemistry showed that FSGS (n = 22) had increased uPAR expression in podocytes compared with both the MCD group (n = 16; p = 0.0368) and control group (n = 21; p = 0.0076). ROC curve (p = 0.008) showed that this biomarker has 80.95% of specificity in biopsies of patients with FSGS. Therefore, uPAR presented a high specificity in cases of podocytopathies associated with sclerosis and it can be considered a potential biomarker for FSGS.
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Amniotic fluid stem cell-derived vesicles protect from VEGF-induced endothelial damage. Sci Rep 2017; 7:16875. [PMID: 29203902 PMCID: PMC5715019 DOI: 10.1038/s41598-017-17061-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/21/2017] [Indexed: 11/14/2022] Open
Abstract
Injection of amniotic fluid stem cells (AFSC) delays the course of progression of renal fibrosis in animals with Alport Syndrome, enhancing kidney function and improving survival. The mechanisms responsible for these protective outcomes are still largely unknown. Here, we showed that vascular endothelial growth factor (VEGF) signaling within the glomeruli of Alport mice is strongly elevated early on in the disease, causing glomerular endothelial cell damage. Intraventricular injected AFSC that homed within the glomeruli showed strong modulation of the VEGF activity, particularly in glomerular endothelial cells. To investigate this phenomenon we hypothesized that extracellular vesicles (EVs) produced by the AFSC could be responsible for the observed renoprotection. AFSC derived EVs presented exosomal and stem cell markers on their surface membrane, including VEGFR1 and VEGFR2. EVs were able to modulate VEGF in glomerular endothelial cells by effectively trapping the excess VEGF through VEGFR1-binding preventing cellular damage. In contrast, VEGFR1/sVEGFR1 knockout EVs failed to show similar protection, thus indicating that VEGF trapping is a potentially viable mechanism for AFSC-EV mediated renoprotection. Taken together, our findings establish that EVs secreted by AFSC could target a specific signaling pathway within the glomerulus, thus representing a new potential glomerulus-specific targeted intervention.
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Liebisch M, Bondeva T, Franke S, Hause S, Wolf G. Growth arrest specific 2-like protein 1 expression is upregulated in podocytes through advanced glycation end-products. Nephrol Dial Transplant 2017; 32:641-653. [PMID: 27638909 DOI: 10.1093/ndt/gfw313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/11/2016] [Indexed: 12/21/2022] Open
Abstract
Background Growth arrest specific 2-like protein 1 (GAS2L1) protein is a member of the GAS2 family of proteins, known to regulate apoptosis and cellular cytoskeleton reorganization in different cells. Recently we identified that Gas2l1 gene expression in podocytes is influenced by advanced glycation end product-bovine serum albumin(AGE-BSA). Methods The study was performed employing cultured podocytes and diabetic ( db/db ) mice, a model of type 2 diabetes. Akbuminuria as wellas urinary neutrophil gelatinase-associated lipocalin (NGAL) excretion as measured with specific ELISAs. Gene expression was analysed via semiquantitative and real-time polymerase chain reaction. The protein levels were determined by western blotting and immunostaining. Results We found that the Gas2l1 α isoform is expressed in podocytes. Treatment with AGE-BSA induced Gas2l1 α and Gas2 mRNA levels compared with controls incubated with non-glycated control BSA (Co-BSA). Moreover, application of the recombinant soluble receptor of AGEs (sRAGE), a competitor of cellular RAGE, reversed the AGE-BSA effect. Interestingly, AGE-BSA also increased the protein levels of GAS2L1α in a RAGE-dependent manner, but did not affect the GAS2 expression. Periodic acid-Schiff staining and albuminuria as well as urinary NGAL excretion revealed that db/db mice progressively developed diabetic nephropathy with renal accumulation of N ε -carboxy-methyl-lysine (immunohistochemistry, western blots). Analyses of GAS2L1α and GAS2 proteins in diabetic mice revealed that both were significantly elevated relative to their non-diabetic littermates. In addition, GAS2L1α and GAS2 proteins positively correlated with the accumulation of AGEs in the blood plasma of diabetic mice and the administration of sRAGE in diabetic mice reduced the glomerular expression of both proteins. Conclusions We show for the first time that the protein expression of GAS2L1α in vitro and in vivo is regulated by the AGE-RAGE axis. The suppression of AGE ligation with their RAGE in diabetic mice with progressive nephropathy reversed the GAS2L1α expression, thus suggesting a role of GAS2L1α in the development of diabetic disease, which needs to be further elucidated.
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Affiliation(s)
- Marita Liebisch
- Department of Internal Medicine III, Jena University Hospital, Erlanger Allee, Jena, Germany
| | - Tzvetanka Bondeva
- Department of Internal Medicine III, Jena University Hospital, Erlanger Allee, Jena, Germany
| | - Sybille Franke
- Department of Internal Medicine III, Jena University Hospital, Erlanger Allee, Jena, Germany
| | - Stephan Hause
- Department of Internal Medicine III, Jena University Hospital, Erlanger Allee, Jena, Germany
| | - Gunter Wolf
- Department of Internal Medicine III, Jena University Hospital, Erlanger Allee, Jena, Germany
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11
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Yang SH, Choi JW, Huh D, Jo HA, Kim S, Lim CS, Lee JC, Kim HC, Kwon HM, Jeong CW, Kwak C, Joo KW, Kim YS, Kim DK. Roles of fluid shear stress and retinoic acid in the differentiation of primary cultured human podocytes. Exp Cell Res 2017; 354:48-56. [PMID: 28320523 DOI: 10.1016/j.yexcr.2017.03.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 03/10/2017] [Accepted: 03/13/2017] [Indexed: 12/14/2022]
Abstract
Due to the distinct features that distinguish immortalized podocyte cell lines from their in vivo counterparts, primary cultured human podocytes might be a superior cell model for glomerular disease studies. However, the podocyte de-differentiation that occurs in culture remains an unresolved problem. Here, we present a method to differentiate primary cultured podocytes using retinoic acid (RA) and fluid shear stress (FSS), which mimic the in vivo environment of the glomerulus. RA treatment induced changes in the cell shape of podocytes from a cobblestone-like morphology to an arborized configuration with enhanced mobility. Moreover, the expression of synaptopodin and zonula occludens (ZO)-1 in RA-treated podocytes increased along with Krüppel-like factor 15 (KLF15) expression. Confocal microscopy revealed that RA increased the expression of cytoplasmic synaptopodin, which adopted a filamentous arrangement, and junctional ZO-1 expression, which showed a zipper-like pattern. To elucidate the effect of FSS in addition to RA, the podocytes were cultured in microfluidic devices and assigned to the static, static+RA, FSS, and FSS+RA groups. The FSS+RA group showed increased synaptopodin and ZO-1 expression with prominent spikes on the cell-cell interface. Furthermore, interdigitating processes were only observed in the FSS+RA group. Consistent with these data, the mRNA expression levels of synaptopodin, podocin, WT-1 and ZO-1 were synergistically increased by FSS and RA treatment. Additionally, the heights of the cells were greater in the FSS and FSS+RA groups than in the static groups, suggesting a restoration of the 3D cellular shape. Meanwhile, the expression of KLF15 increased in the RA-treated cells regardless of fluidic condition. Taken together, FSS and RA may contribute through different but additive mechanisms to the differentiation of podocytes. These cells may serve as a useful tool for mechanistic studies and the application of regenerative medicine to the treatment of kidney diseases.
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Affiliation(s)
- Seung Hee Yang
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Kidney Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Jin Woo Choi
- Interdisciplinary Program in Bioengineering Major, Graduate School, Seoul National University, Seoul, Republic of Korea
| | - Dongeun Huh
- Department of Bioengineering, University of Pennsylvania, Philadelphia, USA
| | - Hyung Ah Jo
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sejoong Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Chun Soo Lim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Kidney Research Institute, Seoul National University, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Jung Chan Lee
- Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Biomedical Engineering, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul, Republic of Korea
| | - Hee Chan Kim
- Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Biomedical Engineering, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul, Republic of Korea
| | - Hyug Moo Kwon
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Chang Wook Jeong
- Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Cheol Kwak
- Department of Urology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kwon Wook Joo
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Kidney Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Yon Su Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Kidney Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Dong Ki Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Kidney Research Institute, Seoul National University, Seoul, Republic of Korea.
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12
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Wang L, Yao X, Li Q, Sun S. Effect of Simvastatin on Lipid Accumulation and the Expression of CXCL16 and Nephrin in Podocyte Induced by Oxidized LDL. J INVEST SURG 2017. [PMID: 28635512 DOI: 10.1080/08941939.2016.1278057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To investigate the effect of simvastatin on lipid accumulation and the expression of CXCL16 and Nephrin in murine podocytes induced by oxidized LDL (OxLDL) in order to explore the mechanism of protection. METHODS Murine podocytes (MPC5) were incubated with OxLDL (80 μg/ml) at different concentrations of simvastatin (0, 1.0, and 2.0 μg/ml) for 48 hours. Oil red O staining was used for the assessment of lipid accumulation in podocytes, and colorimetric cholesterol detection kit was used for the quantitative measurement. CXCL16 and Nephrin expression were detected by using Western blot. RESULTS OxLDL-treated MPC5 cells exhibited significantly higher intracellular lipid accumulations compared with the untreated group. Colorimetric detection found that total cholesterol was 90.3 ± 30.1 μg/ml in untreated cells and 226.5 ± 21.6 μg/ml in OxLDL-treated cells. The difference was statistically significant (p < .01). While cells were treated with both OxLDL and simvastatin, we observed little lipid accumulation. Total cholesterol in OxLDL + simvastatin cells were 151.8 ± 6.8 μg/ml and 135.5 ± 26.9 μg/ml under 1.0 μg/ml or 2.0 μg/ml of simvastatin treatment, respectively. Both were statistically significantly lower than that of the OxLDL treated cells (p < .05). Western blot analysis showed that CXCL16 expression was significantly increased (p < .05) in OxLDL-treated cells compared with the untreated cells, and was significantly inhibited by application of simvastatin (p < .05). The analysis of nephrin expression showed that there were no changes in group simvastatin compared with that of control group (p > .05). Nephrin expression was significantly reduced by treatment with OxLDL (p < .01), and was significantly increased by application of simvastatin (p < .05). CONCLUSION Simvastatin treatment could significantly decrease lipid accumulation in murine podocytes and this protective effect was realized through inhibition of the expression of CXCL16 and increase in the expression of nephrin.
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Affiliation(s)
- Li Wang
- a Department of Pediatrics , Shandong Provincial Hospital Affiliated to Shandong University , 324 Jing Wu Road, Jinan 250021 , P. R. China
| | - Xiujun Yao
- a Department of Pediatrics , Shandong Provincial Hospital Affiliated to Shandong University , 324 Jing Wu Road, Jinan 250021 , P. R. China
| | - Qian Li
- a Department of Pediatrics , Shandong Provincial Hospital Affiliated to Shandong University , 324 Jing Wu Road, Jinan 250021 , P. R. China
| | - Shuzhen Sun
- a Department of Pediatrics , Shandong Provincial Hospital Affiliated to Shandong University , 324 Jing Wu Road, Jinan 250021 , P. R. China
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13
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Öhrvik H, Aaseth J, Horn N. Orchestration of dynamic copper navigation – new and missing pieces. Metallomics 2017; 9:1204-1229. [DOI: 10.1039/c7mt00010c] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A general principle in all cells in the body is that an essential metal – here copper – is taken up at the plasma membrane, directed through cellular compartments for use in specific enzymes and pathways, stored in specific scavenging molecules if in surplus, and finally expelled from the cells.
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Affiliation(s)
- Helena Öhrvik
- Medical Biochemistry and Microbiology
- Uppsala University
- Sweden
| | - Jan Aaseth
- Innlandet Hospital Trust and Inland Norway University of Applied Sciences
- Norway
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14
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Abstract
The glomerulus has 3 resident cells namely mesangial cells that produce the mesangial matrix, endothelial cells that line the glomerular capillaries, and podocytes that cover the outer surface of the glomerular basement membrane. Parietal epithelial cells (PrECs), which line the Bowman's capsule are not part of the glomerular tuft but may have an important role in the normal function of the glomerulus. A significant progress has been made in recent years regarding our understanding of the role and function of these cells in normal kidney and in kidneys with various types of glomerulopathy. In crescentic glomerulonephritis necrotizing injury of the glomerular tuft results in activation and leakage of fibrinogen which provides the trigger for excessive proliferation of PrECs giving rise to glomerular crescents. In cases of collapsing glomerulopathy, podocyte injury causes collapse of the glomerular capillaries and activation and proliferation of PrECs, which accumulate within the urinary space in the form of pseudocrescents. Many of the noninflammatory glomerular lesions such as focal segmental glomerulosclerosis and global glomerulosclerosis also result from podocyte injury which causes variable loss of podocytes. In these cases podocyte injury leads to activation of PrECs that extend on to the glomerular tuft where they cause segmental and/or global sclerosis by producing excess matrix, resulting in obliteration of the capillary lumina. In diabetic nephropathy, in addition to increased matrix production in the mesangium and glomerular basement membranes, increased loss of podocytes is an important determinant of long-term prognosis. Contrary to prior belief there is no convincing evidence for an active podocyte proliferation in any of the above mentioned glomerulopathies.
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15
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Guo Y, Deng X, Chen S, Yang L, Ni J, Wang R, Lin J, Bai M, Jia Z, Huang S, Zhang A. MicroRNA-30e targets BNIP3L to protect against aldosterone-induced podocyte apoptosis and mitochondrial dysfunction. Am J Physiol Renal Physiol 2016; 312:F589-F598. [PMID: 27974319 DOI: 10.1152/ajprenal.00486.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/07/2016] [Accepted: 12/07/2016] [Indexed: 12/20/2022] Open
Abstract
MicroRNAs are essential for the maintenance of podocyte homeostasis. Emerging evidence has demonstrated a protective role of microRNA-30a (miR-30a), a member of the miR-30 family, in podocyte injury. However, the roles of other miR-30 family members in podocyte injury are unclear. The present study was undertaken to investigate the contribution of miR-30e to the pathogenesis of podocyte injury induced by aldosterone (Aldo), as well as the underlying mechanism. After Aldo treatment, miR-30e was reduced in a dose-and time-dependent manner. Notably, overexpression of miR-30e markedly attenuated Aldo-induced apoptosis in podocytes. In agreement with this finding, miR-30e silencing led to significant podocyte apoptosis. Mitochondrial dysfunction (MtD) has been shown to be an early event in Aldo-induced podocyte injury. Here we found that overexpression of miR-30e improved Aldo-induced MtD while miR-30e silencing resulted in MtD. Next, we found that miR-30e could directly target the BCL2/adenovirus E1B-interacting protein 3-like (BNIP3L) gene. Aldo markedly enhanced BNIP3L expression in podocytes, and silencing of BNIP3L largely abolished Aldo-induced MtD and cell apoptosis. On the contrary, overexpression of BNIP3L induced MtD and apoptosis in podocytes. Together, these findings demonstrate that miR-30e protects mitochondria and podocytes from Aldo challenge by targeting BNIP3L.
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Affiliation(s)
- Yan Guo
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Xu Deng
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Shuang Chen
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Lingyun Yang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Jiajia Ni
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Rong Wang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Jiajuan Lin
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Mi Bai
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Zhanjun Jia
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Songming Huang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Aihua Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China; and .,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China
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16
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Marshall CB. Rethinking glomerular basement membrane thickening in diabetic nephropathy: adaptive or pathogenic? Am J Physiol Renal Physiol 2016; 311:F831-F843. [PMID: 27582102 DOI: 10.1152/ajprenal.00313.2016] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/21/2016] [Indexed: 12/12/2022] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of chronic kidney disease in the United States and is a major cause of cardiovascular disease and death. DN develops insidiously over a span of years before clinical manifestations, including microalbuminuria and declining glomerular filtration rate (GFR), are evident. During the clinically silent period, structural lesions develop, including glomerular basement membrane (GBM) thickening, mesangial expansion, and glomerulosclerosis. Once microalbuminuria is clinically apparent, structural lesions are often considerably advanced, and GFR decline may then proceed rapidly toward end-stage kidney disease. Given the current lack of sensitive biomarkers for detecting early DN, a shift in focus toward examining the cellular and molecular basis for the earliest structural change in DN, i.e., GBM thickening, may be warranted. Observed within one to two years following the onset of diabetes, GBM thickening precedes clinically evident albuminuria. In the mature glomerulus, the podocyte is likely key in modifying the GBM, synthesizing and assembling matrix components, both in physiological and pathological states. Podocytes also secrete matrix metalloproteinases, crucial mediators in extracellular matrix turnover. Studies have shown that the critical podocyte-GBM interface is disrupted in the diabetic milieu. Just as healthy podocytes are essential for maintaining the normal GBM structure and function, injured podocytes likely have a fundamental role in upsetting the balance between the GBM's synthetic and degradative pathways. This article will explore the biological significance of GBM thickening in DN by reviewing what is known about the GBM's formation, its maintenance during health, and its disruption in DN.
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Affiliation(s)
- Caroline B Marshall
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and Department of Veterans Affairs Medical Center, Birmingham, Alabama
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17
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Muthenna P, Raghu G, Kumar PA, Surekha M, Reddy GB. Effect of cinnamon and its procyanidin-B2 enriched fraction on diabetic nephropathy in rats. Chem Biol Interact 2014; 222:68-76. [DOI: 10.1016/j.cbi.2014.08.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 08/23/2014] [Accepted: 08/27/2014] [Indexed: 01/17/2023]
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18
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Bao L, Cai X, Dai X, Ding Y, Jiang Y, Li Y, Zhang Z, Li Y. Grape seed proanthocyanidin extracts ameliorate podocyte injury by activating peroxisome proliferator-activated receptor-γ coactivator 1α in low-dose streptozotocin-and high-carbohydrate/high-fat diet-induced diabetic rats. Food Funct 2014; 5:1872-80. [DOI: 10.1039/c4fo00340c] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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19
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Zhang YJ, Tian ZL, Yu XY, Zhao XX, Yao L. Activation of integrin β1-focal adhesion kinase-RasGTP pathway plays a critical role in TGF beta1-induced podocyte injury. Cell Signal 2013; 25:2769-79. [DOI: 10.1016/j.cellsig.2013.08.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 08/31/2013] [Indexed: 12/22/2022]
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20
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A compendium of urinary biomarkers indicative of glomerular podocytopathy. PATHOLOGY RESEARCH INTERNATIONAL 2013; 2013:782395. [PMID: 24327929 PMCID: PMC3845336 DOI: 10.1155/2013/782395] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/10/2013] [Indexed: 12/18/2022]
Abstract
It is well known that glomerular podocyte injury and loss are present in numerous nephropathies and that the pathophysiologic consecution of disease hinges upon the fate of the podocyte. While multiple factors play a hand in glomerulopathy progression, basic logic lends that if one monitors the podocyte's status, that may reflect the status of disease. Recent investigations have focused on what one can elucidate from the noninvasive collection of urine, and have proven that certain, specific biomarkers of podocytes can be readily identified via varying techniques. This paper has brought together all described urinary biomarkers of podocyte injury and is made to provide a concise summary of their utility and testing in laboratory and clinical theatres. While promising in the potential that they hold as tools for clinicians and investigators, the described biomarkers require further comprehensive vetting in the form of larger clinical trials and studies that would give their value true weight. These urinary biomarkers are put forth as novel indicators of glomerular disease presence, disease progression, and therapeutic efficacy that in some cases may be more advantageous than the established parameters/measures currently used in practice.
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21
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Petrakis I, Mavroeidi V, Stylianou K, Andronikidi E, Lioudaki E, Perakis K, Stratigis S, Vardaki E, Zafeiri M, Giannakakis K, Plaitakis A, Amoiridis G, Saraiva MJ, Daphnis E. Hsf-1 affects podocyte markers NPHS1, NPHS2 and WT1 in a transgenic mouse model of TTRVal30Met-related amyloidosis. Amyloid 2013; 20:164-72. [PMID: 23829269 DOI: 10.3109/13506129.2013.814046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Familial amyloid polyneuropathy is characterized by transthyretin (TTR) deposition in various tissues, including the kidneys. While deposition induces organ dysfunction, renal involvement in TTR-related amyloidosis could manifest from proteinuria to end-stage kidney failure. As proteinuria is considered result of glomerular filtration barrier injury we investigated whether TTR deposition affects either glomerular basement membrane (GBM) or podocytes. MATERIALS AND METHODS Immunohistochemistry, immunoblot and gene expression studies for nephrin, podocin and WT1 were run on renal tissue from human-TTRV30M transgenic mice hemizygous or homozygous for heat shock factor one (Hsf-1). Transmission electron microscopy was used for evaluation of podocyte foot process width (PFW) and GBM thickness in Hsf-1 hemizygous mice with or without TTRV30M or amyloid deposition. RESULTS Glomeruli of hsf-1 hemizygous transgenic mice showed lower nephrin and podocin protein levels but an increased podocyte number when compared to Hsf-1 homozygous transgenic mice. Nephrin, podocin and WT1 gene expression levels were unaffected by the Hsf-1 carrier status. TTRV30M deposition was associated with increased PFW and GBM thickness. CONCLUSIONS Under the effect of Hsf-1 hemizygosity, TTRV30M deposition has deleterious effects on GBM thickness, PFW and slit diaphragm composition, without affecting nephrin and podocin gene expression.
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22
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Pollinger K, Hennig R, Breunig M, Tessmar J, Ohlmann A, Tamm ER, Witzgall R, Goepferich A. Kidney podocytes as specific targets for cyclo(RGDfC)-modified nanoparticles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:3368-75. [PMID: 22888052 DOI: 10.1002/smll.201200733] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/04/2012] [Indexed: 05/08/2023]
Abstract
Renal nanoparticle passage opens the door for targeting new cells like podocytes, which constitute the exterior part of the renal filter. When cyclo(RGDfC)-modified Qdots are tested on isolated primary podocytes for selective binding to the αvβ3 integrin receptor a highly cell- and receptor-specific binding can be observed. In displacement experiments with free cyclo(RGDfC) IC(50) values of 150 nM for αvβ3 integrin over-expressing U87-MG cells and 60 nM for podocytes are measured. Confocal microscopy shows a cellular Qdot uptake into vesicle-like structures. Our ex vivo study gives clear evidence that, after renal filtration, nanoparticles can be targeted to podocyte integrin receptors in the future. This could be a highly promising approach for future therapy and diagnostics of podocyte-associated diseases.
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Affiliation(s)
- Klaus Pollinger
- Department of Pharmaceutical Technology, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
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23
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Activation of peroxisome proliferator-activated receptor-γ coactivator 1α ameliorates mitochondrial dysfunction and protects podocytes from aldosterone-induced injury. Kidney Int 2012; 82:771-89. [DOI: 10.1038/ki.2012.188] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Moysiadis DK, Perysinaki GS, Bertsias G, Stratakis S, Kyriacou K, Nakopoulou L, Boumpas DT, Daphnis E. Early treatment with glucocorticoids or cyclophosphamide retains the slit diaphragm proteins nephrin and podocin in experimental lupus nephritis. Lupus 2012; 21:1196-207. [DOI: 10.1177/0961203312451784] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Renal podocytes and their slit diaphragms ensure the integrity of renal basement membrane and prevent urinary protein loss. We have previously reported that decreases of the podocyte slit diaphragm proteins nephrin and podocin represent early events in the podocytopathy of lupus nephritis (LN). We asked whether immunosuppressive agents such as glucocorticoids and cyclophosphamide may have direct effects on podocytes. We assessed in New Zealand Black/New Zealand White (NZB/W) F1 LN mice glomerular nephrin and podocin expression and localization by the use of Western blot and immunofluorescence; mRNA levels were measured by real-time polymerase chain reaction (PCR) and renal histology by light and electron microscopy. Early treatment with glucocorticoids and cyclophosphamide halted the histologic alterations associated with LN, preserving podocyte foot processes. Nephrin and podocin protein expression significantly increased in both glucocorticoid and cyclophosphamide groups as early as after three months of therapy. Real-time PCR revealed similar enhancement in nephrin and podocin mRNA levels after three to six months of treatment. This study documents that early treatment in experimental LN with glucocorticoids or cyclophosphamide preserves slit diaphragm proteins in podocytes and halts histological changes of the glomeruli, thus raising the possibility of a direct protective effect of these drugs on podocytes.
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Affiliation(s)
- DK Moysiadis
- Laboratory of Nephrology, Medical Department, University of Crete, Greece
| | - GS Perysinaki
- Laboratory of Nephrology, Medical Department, University of Crete, Greece
| | - G Bertsias
- Rheumatology, Clinical Immunology and Allergy, Medical Department, University of Crete, Greece
| | - S Stratakis
- Laboratory of Nephrology, Medical Department, University of Crete, Greece
| | - K Kyriacou
- Department of Electron Microscopy/Molecular Pathology, The Cyprus Institute of Neurology and Genetics, Cyprus
| | - L Nakopoulou
- Pathology Department, Medical School, National Kapodistrian University of Athens, Greece
| | - DT Boumpas
- Rheumatology, Clinical Immunology and Allergy, Medical Department, University of Crete, Greece
| | - E Daphnis
- Laboratory of Nephrology, Medical Department, University of Crete, Greece
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Khurana S, Chakraborty S, Lam M, Liu Y, Su YT, Zhao X, Saleem MA, Mathieson PW, Bruggeman LA, Kao HY. Familial focal segmental glomerulosclerosis (FSGS)-linked α-actinin 4 (ACTN4) protein mutants lose ability to activate transcription by nuclear hormone receptors. J Biol Chem 2012; 287:12027-35. [PMID: 22351778 DOI: 10.1074/jbc.m112.345421] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mutations in α-actinin 4 (ACTN4) are linked to familial forms of focal segmental glomerulosclerosis (FSGS), a kidney disease characterized by proteinuria due to podocyte injury. The mechanisms underlying ACTN4 mutant-associated FSGS are not completely understood. Although α-actinins are better known to cross-link actin filaments and modulate cytoskeletal organization, we have previously shown that ACTN4 interacts with transcription factors including estrogen receptor and MEF2s and potentiates their transcriptional activity. Nuclear receptors including retinoic acid receptor (RAR) have been proposed to play a protective role in podocytes. We show here that ACTN4 interacts with and enhances transcriptional activation by RARα. In addition, FSGS-linked ACTN4 mutants not only mislocalized to the cytoplasm, but also lost their ability to associate with nuclear receptors. Consequently, FSGS-linked ACTN4 mutants failed to potentiate transcriptional activation by nuclear hormone receptors in podocytes. In addition, overexpression of these mutants suppressed the transcriptional activity mediated by endogenous wild-type ACTN4 possibly by a cytoplasmic sequestration mechanism. Our data provide the first link between FSGS-linked ACTN4 mutants and transcriptional activation by nuclear receptor such as RARα and peroxisome proliferator-activated receptor γ.
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Affiliation(s)
- Simran Khurana
- Department of Biochemistry, School of Medicine, Case Western Reserve University and Research Institute of University Hospitals of Cleveland, Cleveland, Ohio 44106, USA
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Liu Z, Blattner SM, Tu Y, Tisherman R, Wang JH, Rastaldi MP, Kretzler M, Wu C. Alpha-actinin-4 and CLP36 protein deficiencies contribute to podocyte defects in multiple human glomerulopathies. J Biol Chem 2011; 286:30795-30805. [PMID: 21680739 DOI: 10.1074/jbc.m111.255984] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Genetic alterations of α-actinin-4 can cause podocyte injury through multiple mechanisms. Although a mechanism involving gain-of-α-actinin-4 function was well described and is responsible for a dominantly inherited form of human focal segmental glomerulosclerosis (FSGS), evidence supporting mechanisms involving loss-of-α-actinin-4 function in human glomerular diseases remains elusive. Here we show that α-actinin-4 deficiency occurs in multiple human primary glomerulopathies including sporadic FSGS, minimal change disease, and IgA nephropathy. Furthermore, we identify a close correlation between the levels of α-actinin-4 and CLP36, which form a complex in normal podocytes, in human glomerular diseases. siRNA-mediated depletion of α-actinin-4 in human podocytes resulted in a marked reduction of the CLP36 level. Additionally, two FSGS-associated α-actinin-4 mutations (R310Q and Q348R) inhibited the complex formation between α-actinin-4 and CLP36. Inhibition of the α-actinin-4-CLP36 complex, like loss of α-actinin-4, markedly reduced the level of CLP36 in podocytes. Finally, reduction of the CLP36 level or disruption of the α-actinin-4-CLP36 complex significantly inhibited RhoA activity and generation of traction force in podocytes. Our studies reveal a critical role of the α-actinin-4-CLP36 complex in podocytes and provide an explanation as to how α-actinin-4 deficiency or mutations found in human patients could contribute to podocyte defects and glomerular failure through a loss-of-function mechanism.
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Affiliation(s)
- Zhongmin Liu
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | | | - Yizeng Tu
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Robert Tisherman
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - James H Wang
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Maria Pia Rastaldi
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico e Fondazione D'Amico per la Ricerca sulle Malattie Renali, Milano 20122, Italy
| | - Matthias Kretzler
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Chuanyue Wu
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261.
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