The Effect Of Autophagy On The Apoptosis Of Mesangial Cells Treated By Aldosterone

BackgroundMesangial cell(MC)is a kind of glomerular cells.The MC conditions are contributed to the normal structure and function of kidney.Recently,the interest is growing in MC apoptosis as a potential contributor to the renal lesion.Studies have shown that aldosterone(ALD)can directly induce MC apoptosis,then damage the kidney,but the mechanism by which aldosterone regulates apoptosis remains unclear.In this study,we explored the relationship between autophagy and apoptosis in MC by observing the features of autophagy and apoptosis of aldosterone,Bufalin and autophagy inhibitor chloroquine(CQ)packet on rat mesangial cells.The results may provide the corresponding experimental foundation and theoretical basis for the clinical application of aldosterone receptor antagonist and Bufalin in the treatment of kidney disease.Methods1.Rat mesangial cells(MCs)were cultured in vitro and divided into six groups:control group(A),aldosterone group(B),Bufalin group(C),ALD+Bufalin group(D),ALD+CQ group(E),ALD+Bufalin+CQ group(F);2.Effects of toxicity on MC treated by different concentrations of aldosterone(10-7mol/L,10-6mol/L,10-5mol/L,10-4mol/L and 10-3mol/L)were detemined by Trypan blue method;3.The autophagosome of MCs in different groups was observed by transmission electron microscopy;4.The expression of proteins was detected by Western blot;5.Effect of apoptosis of mesangial cells in different groups were determined by flow cytometry.Results1.There was no significant cell toxicity observed when aldosterone was applied at the concentrations of 10-7mol/L,10-6mol/L and 10-5mol/L by Trypan blue method.2.Transmission electron microscopy showed that:No typical autophagosome could be found in control group and bufalin group;Typical autophagosomes could be found in ALD group;The number of Autophagosomes in group D is less then ALD group;The number of Autophagosomes in group E and group F is significantly higher than other groups.3.Western blot indicated that:Expression levels of LC3 and P62 in bufalin group and control group were basically the same;Compared with the control group and bufalin group,the expression level of ALD group increased significantly(P<0.05);Compared with the ALD group,the expression level of group D decreased significantly(P<0.05);Compared with other groups,the expression levels of group E and group F increased significantly(P<0.05).4.Flow cytometric analysis suggested that:Apoptosis rates of the bufalin group[(46.23±5.83)%]and control group[(46.10±3.49)%]were basically the same;Compared with the control group,the apoptosis rate of the aldosterone group[(76.47±3.03)%]increased significantly(P<0.05);The apoptosis rates of group D[(61.73±2.76)%],group E[(61.03±3.62)%]and group F[(60.50±1.95)%]were basically the same,and higher than control group,inferior to ALD group.ConclusionsAldosterone could induce autophagy as well as apoptosis in the mesangial cells,bufalin and chloroquine could attenuate the effects of aldosterone promote autophagy and apoptosis.The study showed that the autophagy of MCs could promote apoptsis,alosterone could increase the apoptsis of MCs by promoting autophagy.