Role of reactive oxygen species in podocytes apoptosis induced by aldosterone / 中华肾脏病杂志

ABSTRACT

Objective To access the effects of aldosterone (ALD) and its receptor antagonist- spironolactone (SPI) on the production of reactive oxygen species (ROS) and apoptosis in podocytes and to explore the possible mechanism involved. Methods Conditionally immortalized mouse podocytes were divided into control group, ALD group, SPI group and SPI +ALD group. The level of ROS production and the expression of nephrin protein were assayed by fluorescent spectrophotometry and indirect immunofluorescence technology. The apoptosis rate of podocytes was monitored by flow cytometry. The expression of bax and bcl-2 mRNA and protein was detected by RT-PCR and Western blotting methods. The anti-oxidant N-acetylcysteine (NAC)was applied to determine whether the effects of ALD on podocytes were mediated by ROS pathway.Results Compared with the control group, ALD significantly increased ROS production in podocytes (P＜0.05). SPI completely abolished the above-mentioned effect of ALD (P＜0.05). ALD induced the down-regulation of the expression of nephrin and the up-regulation of podocytes apoptosis (P＜0.05), which was accompanied with the elevated expression of bax mRNA and protein and the reduced expression of bcl-2 mRNA and protein (P＜0.05). SPI or NAC prevented the above-mentioned changes induced by ALD (P＜0.05). Conclusion ALD increases theexpression of pro-apoptotic factor (bax) but decreases the expression of anti-apoptotic factor (bcl-2)to induce podocytes apoptosis through the mineralocorticoid receptor (MR) possibly via the mechanisms involving ROS pathway.