Abstract: SA-PO517
Parkin Accelerates Tubular Cell Senescence Through GATA4/GAS1 in Diabetic Nephropathy
Session Information
- Diabetic Kidney Disease: Basic - III
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 601 Diabetic Kidney Disease: Basic
Authors
- Chen, Kehong, Daping hospital, Chongqing, China
- Chen, Jia, Daping hospital, Chongqing, China
- He, Yani, Daping hospital, Chongqing, China
Background
Accelerated senescence of renal tubular epithelial cell (RTEC) plays a fundamental role in the pathogenesis of diabetic nephropathy (DN). Gene mutation of Parkin, an E3 ubiquitin ligase, can accelerate neuron degeneration in familial aging-related diseases. We investigated the role of Parkin in accelerating senescence of RTEC and its mechanism.
Methods
149 cases of patients with DN diagnosed by renal biopsy were recruited in our study. 32 normal kidney samples were obtained from renal carcinoma as control. Renal Parkin expression was detected by immunohistochemistry. In vivo, we used C57BL/6 Parkin-/- knockout mice, Parkin overexpression mice and wild-type controls with or without streptozotocin-induced diabetes over 5 months of follow-up. In vitro, mouse primary RTEC were exposed to high glucose (HG) for 48h. Moreover, co-immunoprecipitation and ubiquitination experiments were applied to evaluate the relationship of GATA4 with Parkin.
Results
Expression of Parkin was gradually decreased with development of tubulointerstitial injury and positively correlated with eGFR. Parkin KO+STZ mice showed significantly higher plasma BUN, SCr and urinary NAG than those in wild-type STZ mice. The degree of renal interstitial fibrosis in the STZ+Parkin overexpression group was significantly lower than that in STZ mice. The proportion of P16-positive renal tubular cells and renal P21 expression in Parkin overexpression + STZ group were significantly lower than those in STZ group. In vitro, overexpression of Parkin attenuates high glucose-induced tubular senescence and GATA4 accumulation. Parkin co-immunoprecipitated with GATA4 in renal biopsy samples of DN patients and mouse tubular cells. Furthermore, Parkin ubiquitinated GATA4 in vivo and in vitro. Parkin KO diabetic nephropathy mice have significantly higher GAS1 mRNA and protein levels in kidneys than WT mice. Overexpression of GATA4 enhanced GAS1 mRNA and protein levels in renal tubular cells. Overexpression of GAS1 can directly inhibit the expression of a key negative regulator of cell senescence, cyclin dependent kinase 2 (CDK2) and inhibit the anti-senescence effect of Parkin in mouse primary RTCs stimulated by high glucose.
Conclusion
Parkin inhibits RTEC senescence in diabetic nephropathy by inhibiting GATA4/GAS1 pathway. Parkin is a potential anti-senescence factor in the development of diabetic nephropathy.
Funding
- Government Support - Non-U.S.