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Vallés-Saiz L, Peinado-Cahuchola R, Ávila J, Hernández F. Microtubule-associated protein tau in murine kidney: role in podocyte architecture. Cell Mol Life Sci 2022; 79:97. [PMID: 35084555 PMCID: PMC8794918 DOI: 10.1007/s00018-021-04106-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/29/2021] [Accepted: 12/19/2021] [Indexed: 12/25/2022]
Abstract
Tau is a cytoskeletal protein that is expressed mainly in neurons and is involved in several cellular processes, such as microtubule stabilization, axonal maintenance, and transport. Altered tau metabolism is related to different tauopathies being the most important Alzheimer's disease where aberrant hyperphosphorylated and aggregated tau is found in the central nervous system. Here, we have analyzed that function in kidney by using tau knockout mice generated by integrating GFP-encoding cDNA into exon 1 of MAPT (here referred to as TauGFP/GFP). IVIS Lumina from PerkinElmer demonstrated GFP expression in the kidney. We then demonstrated by qPCR that the main tau isoform in the kidney is Tau4R. The GFP reporter allowed us to demonstrate that tau is found in the glomeruli of the renal cortex, and specifically in podocytes. This was further confirmed by immunohistochemistry. TauGFP/GFP mice present a podocyte cytoskeleton more dynamic as they contain higher levels of detyrosinated tubulin than wild-type mice. In addition, transmission electron microscopy studies demonstrated glomerular damage with a decrease in urinary creatinine. Our results prove that tau has an important role in kidney metabolism under normal physiological conditions.
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Affiliation(s)
- Laura Vallés-Saiz
- Centro de Biología Molecular "Severo Ochoa", CSIC/UAM, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Rocio Peinado-Cahuchola
- Centro de Biología Molecular "Severo Ochoa", CSIC/UAM, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Jesús Ávila
- Centro de Biología Molecular "Severo Ochoa", CSIC/UAM, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Félix Hernández
- Centro de Biología Molecular "Severo Ochoa", CSIC/UAM, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
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Fang J, Yao X, Hou M, Duan M, Xing L, Huang J, Wang Y, Zhu B, Chen Q, Wang H. ApoL1 induces kidney inflammation through RIG-I/NF-κB activation. Biochem Biophys Res Commun 2020; 527:466-473. [PMID: 32336543 DOI: 10.1016/j.bbrc.2020.04.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/11/2020] [Indexed: 02/07/2023]
Abstract
The genetic variations of the apolipoprotein L1 (APOL1) gene are associated with non-diabetic kidney diseases. However, very little is known about the role of ApoL1 in glomerular damage. Here, we aimed to identify the function and mechanism of ApoL1 in glomerular damage. The mice were randomly divided into two groups: one group was intraperitoneally injected with phosphate buffer saline (PBS), while the other group was intraperitoneally injected with recombinant ApoL1 every other day for 3 months. Hematoxylin and eosin (HE) and periodic acid Schiff (PAS) staining were used to demonstrate the effects of ApoL1 on kidney inflammation and injury. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) analyses revealed that ApoL1-treated mice exhibited enhanced expression of various inflammation markers in the kidney and serum compared to the PBS-treated mice. Immunofluorescence staining revealed that ApoL1 accumulated in kidney podocytes. Treatment with ApoL1 dose-dependently increased the expression of inflammation markers and apoptotic markers. The abnormal gene expression associated with ApoL1-mediated podocyte inflammation was evaluated using microarray analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the upregulated genes were enriched in the inflammation-related processes, such as the RIG-I/NF-κB signaling pathway. Consistently, the knockdown of RIG-I significantly mitigated the ApoL1-induced upregulation of inflammatory and apoptotic markers in the human podocytes. Additionally, the ApoL1-induced glomerular damage was attenuated in AAV-shRIG-I mice. Therefore, the effects of ApoL1 on glomerular damage may be, at least partially, through inducing abnormal expression of inflammatory molecules, which may have important implications for treatment of kidney diseases.
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Affiliation(s)
- Ji Fang
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China
| | - Xingmei Yao
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China
| | - Mingqiang Hou
- Department of Urology, Xishui County People's Hospital, Guizhou Province, Guizhou, 564699, People's Republic of China
| | - Miao Duan
- Department of Urology, Xishui County People's Hospital, Guizhou Province, Guizhou, 564699, People's Republic of China
| | - Lina Xing
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China
| | - Jiebo Huang
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China
| | - Yunman Wang
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China
| | - Bingbing Zhu
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China
| | - Qiujing Chen
- Institute of Cardiovascular Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200025, People's Republic of China.
| | - Hao Wang
- Department of Nephrology, Laboratory of Renal Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200062, People's Republic of China.
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Bus P, Scharpfenecker M, Van Der Wilk P, Wolterbeek R, Bruijn JA, Baelde HJ. The VEGF-A inhibitor sFLT-1 improves renal function by reducing endothelial activation and inflammation in a mouse model of type 1 diabetes. Diabetologia 2017; 60. [PMID: 28620823 PMCID: PMC5552850 DOI: 10.1007/s00125-017-4322-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
AIMS/HYPOTHESIS Animal models of diabetic nephropathy show increased levels of glomerular vascular endothelial growth factor (VEGF)-A, and several studies have shown that inhibiting VEGF-A in animal models of diabetes can prevent albuminuria and glomerular hypertrophy. However, in those studies, treatment was initiated before the onset of kidney damage. Therefore, the aim of this study was to investigate whether transfecting mice with the VEGF-A inhibitor sFlt-1 (encoding soluble fms-related tyrosine kinase 1) can reverse pre-existing kidney damage in a mouse model of type 1 diabetes. In addition, we investigated whether transfection with sFlt-1 can reduce endothelial activation and inflammation in these mice. METHODS Subgroups of untreated 8-week-old female C57BL/6J control (n = 5) and diabetic mice (n = 7) were euthanised 5 weeks after the start of the experiment in order to determine the degree of kidney damage prior to treatment with sFLT-1. Diabetes was induced with three i.p. injections of streptozotocin (75 mg/kg) administered at 2 day intervals. Diabetic nephropathy was then investigated in diabetic mice transfected with sFlt-1 (n = 6); non-diabetic, non-transfected control mice (n = 5); non-diabetic control mice transfected with sFlt-1(n = 10); and non-transfected diabetic mice (n = 6). These mice were euthanised at the end of week 15. Transfection with sFlt-1 was performed in week 6. RESULTS We found that transfection with sFlt-1 significantly reduced kidney damage by normalising albuminuria, glomerular hypertrophy and mesangial matrix content (i.e. glomerular collagen type IV protein levels) (p < 0.001). We also found that transfection with sFlt-1 reduced endothelial activation (p < 0.001), glomerular macrophage infiltration (p < 0.001) and glomerular TNF-α protein levels (p < 0.001). Finally, sFLT-1 decreased VEGF-A-induced endothelial activation in vitro (p < 0.001). CONCLUSIONS/INTERPRETATION These results suggest that sFLT-1 might be beneficial in treating diabetic nephropathy by inhibiting VEGF-A, thereby reducing endothelial activation and glomerular inflammation, and ultimately reversing kidney damage.
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Affiliation(s)
- Pascal Bus
- Department of Pathology, Leiden University Medical Center, L1Q, Room P0-107, P.O. Box 9600, 2300 RC, Leiden, the Netherlands.
| | - Marion Scharpfenecker
- Department of Pathology, Leiden University Medical Center, L1Q, Room P0-107, P.O. Box 9600, 2300 RC, Leiden, the Netherlands
| | - Priscilla Van Der Wilk
- Department of Pathology, Leiden University Medical Center, L1Q, Room P0-107, P.O. Box 9600, 2300 RC, Leiden, the Netherlands
| | - Ron Wolterbeek
- Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, the Netherlands
| | - Jan A Bruijn
- Department of Pathology, Leiden University Medical Center, L1Q, Room P0-107, P.O. Box 9600, 2300 RC, Leiden, the Netherlands
| | - Hans J Baelde
- Department of Pathology, Leiden University Medical Center, L1Q, Room P0-107, P.O. Box 9600, 2300 RC, Leiden, the Netherlands
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