Expression and distribution of podocin in different pathological processes in adriamycin-induced nephrotic rat model

Objective To dynamicly observe the expression and distribution of podocin in different pathological mechanism of adriamycin-inducing nephrotic (ADN) rats,to explore the possible mechanisms of podocin during the occurrence and development of proteinuria.Methods The study had two groups,model group (n=24),control group (n=24).The changes of following indexes were observed at the 1st,2nd,4th,6th weeks.(1) Urine protein quantization of 24 hour,the levels of serum albumin and total cholesterol.(2) The histopathology detection by light microscope.(3) Protein expression of podocin in cortex of kidney detected by Western blot.(4) Examined mRNA expression of podocin in cortex of kidney by real time RT-PCR.(5) The localization of podocin in glomerular by immunofluorescence.Results (1) The model group was observed massive proteinuria,hypoproteinemia and hypercholesterolaemia.(2) In the model group minimal change disease was developed to focal segmental glomerulosclerosis observed by optical microscope and electron microscope.(3) In model group podocin protein expression increased at the 1st,2nd,4th,6th week,most obviously at the 4th week.(4) Compared with the control group,in the model group podocin mRNA expression increased at the 1st week,peaked at the 2nd week,decreased from the 4th week;(5) In model group podocin staining gradually shifted from a linear-like pattern along the capillary loops of glomerulus to a discontinuous coarse granular pattern.Conclusions During the pathological course of AND,it leads to the occurrence and development of the proteinuria and the adnormal expression and distribution of podocin may contribute to the pathological process.