RESUMO
[ ABSTRACT] AIM: To explore whether autophagy is involved in the excessive death of renal tubular epithelial cells in subtotal nephrectomy ( SNx) rats and the relationship between autophagy and necroptosis in the kidney of SNx rats. METHODS:Male Sprague-Dawley rats were randomly assigned to control group ( n=6 ) and SNx group ( n=42 ) .The rats in SNx group were subjected to SNx.Sham surgery was performed in the rats in control group.The rats in SNx group were divided into subgroups at 0, 4, 8 and 12 weeks ( n=6) and the other rats in SNx group were divided into SNx+vehi-cle group, SNx+necrostatin-1 (Nec-1) group and SNx+3-methyladenine (3-MA) group.The expression of RIP1, RIP3, LC3 and beclin-1 at mRNA and protein levels was measured at 0, 4, 8 and 12 weeks by qPCR and immunohistochemistry. The effects of Nec-1 or 3-MA on the protein expression of LC3-I, LC3-II and beclin-1, and production of reactive oxygen species ( ROS) in the rat kidney were determined by Western blot and DCFH-DA staining.The death of renal tubular epi-thelial cells in the SNx rats was observed by TUNEL staining and electron microscopy.Finally, the effects of Nec-1 and 3-MA on blood urea nitrogen ( BUN) , serum creatinine ( SCr) and the pathological changes of the renal tissues were ana-lyzed.RESULTS:The highest mRNA and protein levels of RIP1, RIP3, LC3 and beclin-1 appeared at the 8th week after SNx (P cells were decreased in the SNx rats treated with Nec-1 and 3-MA (P<0.01), but 3-MA did not reduce the increased con-centration of ROS.In addition, treatment with Nec-1 and 3-MA obviously reduced BUN, SCr (P<0.05), glomeruloscle-rosis index and tubulointerstitial injury score (P<0.01).CONCLUSION:Autophagy participates in the excessive death of renal tubular epithelial cells in SNx rats.Inhibition of autograph prevents necroptotic cell death of renal tubular cells, and alleviates chronic renal injury in SNx rats.