Effects of overexpression of TRPC6 on angiotensin Ⅱ-induced apoptosis of mouse podocytes
- VernacularTitle:TRPC6高表达对血管紧张素Ⅱ诱导的小鼠足细胞凋亡的影响
- Author:
Xifeng SUN
;
Chun ZHANG
;
Xiuyan SHI
;
Zhan FANG
;
Zhonghua ZHU
;
Xiao YANG
;
Huajun JIANG
- Publication Type:Journal Article
- Keywords:
Angiotensin Ⅱ;
Apoptosis;
Calcium;
TRPC6;
Podocytes
- From:
Chinese Journal of Nephrology
2008;24(11):797-803
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the effect of overexpression of TRPC6 on Ang Ⅱ-induced apoptosis of mouse podocytes in vitro and to explore the possible mechanisms. Methods Mouse TRPC6 cDNA eukaryotie expression vector pEGFP-NI-mTRPC6 was transfected to conditionally immortalized routine podocyte cell line by liposome. The fluorescent microscopy was used to examine the expression of EGFP after 24 hours. The change of TRPC6 protein expression was observed by Western-blot. Podocytes were treated by different concentrations of Ang Ⅱ. The podocyte intracellular calcium concentration was measured with laser-scanning con_focal microscope. The expression of Bax and Bcl-2 mRNA was assessed by RT-PCR and the expression of Bax and Bcl-2 protein was measured by Western-blot. The apoptotic ratio of podocytes was monitored by flow cytometry and Hoechst staining. Results About 35% of the cells expressed EGFP. An up-regulation of protein expression of TRPC6 was detected in podocytes when transfected with pEGFP-N1-mTRPC6 (P<0.01). The overexpression of TRPC6 promoted the Ang Ⅱ-induced influx of extracellular calcium and elevated the expression of Bax but decreased the expression of Bcl-2 (P<0.01, P<0.05). The apoptotic ratio of podocyte was (2.50±0.72)% when treated by low-dose Ang Ⅱ (10-10 mol/L), and it was increased to (4.33±0.45)% when transfected with pEGFP-N1-mTRPC6 (P <0.05 ). Transfection with pEGFP-NI-mTRPC6 increased apoptosis rate from (15.46± 1.40)% to (18.33±0.87)%(P<0.01) by high-dose Ang Ⅱ (10-6 mol/L). Conclusion TRPC6 plays an important role in the Ang Ⅱ-induced apoptosis of podocytes by promoting the influx of extraeellular calcium, which leads to the apoptosis cascade initiation.
