Study On The Effect Of Qingretongluo Mixture On Podocyte Proteins Nephrin And Podocin In Rats With Diabetic Nephropathy

Objective:this research is to study the efficacy of Qingretongluo Mixture in treating proteinuria in rats with Diabetic Nephropathy(DN) and determine its molecular mechanism in intervening proteinuria and thus to provide theoretic basis for the prevention and treatment of DN proteinuria with traditional Chinese medicine (TCM) through experiments with Streptozotocin (STZ)-induced DN rat model.Methods:STZ-induced rat model for DN was produced, which was then randomly assigned to blank model control group (n=12), TCM group (n=12, Qingretongluo Mixture 21 ml/Kg.d) and Irbesartan control group (n=12, Irbesartan 50mg/Kg.d). When the experiment concluded twelve weeks later, each rat's weight and blood glucose level were measured; its 24-hour urine protein,urine creatihe, blood creatine and BUN were also determined through bio-chemical analysis; Immunohistochemical staining was used in glomerular slit diaphragm proteins nephrin and podocin, which was then analyzed through Computer Graphics; the expression of nephrin mRNA and podocin mRNA were also determined in real time through RT-PCR.Results:(1) 24-hour urine protein:its level in DN rats all increased significantly compared with that in the blank control group, (p<0.05); its level in both TCM group and Irbesartan group decreased noticeably after the intervention by Qingretongluo Mixture and Irbesartan respectively compared with that in the model control group(p<0.05), and its level in TCM group was noticeably lower than that in Irbesartan group(p<0.05). (2) protein nephrin and podocin expression:their expression in DN rats all became significantly weaker compared with that in the blank control group(p<0.05); their expression in both TCM group and Irbesartan group became stronger after the intervention by Qingretongluo Mixture and Irbesartan respectively compared with that in the model control group(p<0.05), and the expression of protein nephrin in TCM group was stronger than that in Irbesartan group(p<0.05) and the difference in the expression of protein podocin in the TCM group and Irbesartan group was not statistically significant (P>0.05). (3) nephrin mRNA and podocin mRNA expression:their expression in DN rats all became significantly weaker compared with that in the blank control group(p<0.05); their expression in both TCM group and Irbesartan group became stronger after the intervention by Qingretongluo Mixture and Irbesartan respectively compared with that in the model control group(p<0.05), and the expression of nephrin mRNA in TCM group was stronger than that in Irbesartan group(p<0.05) and the difference in the expression of podocin mRNA in the TCM group and Irbesartan group was not statistically significant (P>0.05). Changes in nephrin mRNA and podocin mRNA expression followed the same pattern as those in protein expression. (4) Correlation analysis:statistics showed that there was negative correlation between 24-hour urine protein and the expression of proteins nephrin and podocin and the expression of nephrin mRNA and podocin mRNA (P<0.01).Conclusions:(1) Qingretongluo Mixture is able to lower the 24-hour urine protein in the DN rats.(2) Qingretongluo Mixture is able to inhibit the weakening of nephrin and podocin expression caused by diabetes-induced renal damage.(3) There is negative correlation between 24-hour urine protein and the expression of nephrin,podocin mRNA and the expression of proteins nephrin and podocin in DN rats.