Expression and significance of Pdlim2 in the glomerular podocyte of hyperlipidemic rats / 中华肾脏病杂志

ABSTRACT

Objective To investigate the expression changes and significance of Pdlim2 in the glomerular podocyte of hyperlipidemic rats.Methods Forty-five individuals of SD rats were divided randomly into 3 groups (n =15 in each group).The control group was fed with normal diet.The high fat group was fed with high fat diet.The simvastatin group was fed with high fat diet plus with simvastatin gavage (10 mg· kg-1 · d-1).Five rats were sampled randomly from each group at week 4,6,and 10 and the urinary protein excretion,the concentration of serum cholesterol,and the concentration of low density lipoprotein cholestorol were determined,the glomerular podocyte damage in rats was detected by electron microscope,the expression of Pdlim2 protein was determined by immunohistochemistry and by Western blotting.Results The levels of serum cholesterol and low density lipoprotein cholestorol increased significantly in high fat group and simvastatin group at week 4 compared to that in control group(P ＜ 0.05),and the level in simvastatin group was significantly decreased compared with that in high fat group(P ＜ 0.05).The urinary protein levels of high fat group and simvastatin group were significantly higher than that in control group at week 10,and the level in simvastatin group was significantly decreased in high fat group,there was significant difference in each group of comparison(P ＜ 0.05).Podocyte injury was detected by electronic microscopy in high fat group at week 4,and the injury became more serious as the treatment time increased.Podocyte injury in the simvastatin group was significantly less than that in the high fat group and the control group at week 10.The positive staining of Pdlim2 was mainly in the glomeruli and the expression of Pdlim2 of the high fat group was lower than the simvastatin group,and both were lower than the control group at week 10.The expression of Pdlim2 protein of high fat group was lower than that in the control group since week 4(P ＜0.05).The expression of Pdlim2 protein of high fat group was lower than that in the simvastatin group (P＜0.05),and both were lower than the control group at week 10(P＜0.05).Conclusions Hypedipidemia induces podocyte injury before urinary protein,which is suggested to be associated with the decrease of Pdlim2 protein.Simvastatin reduces podocyte toot processes of high fat induced fusion,which may be through protecting the expression of glomerular Pdlim2.