Taurine Ameliorates Apoptosis via AKT Pathway in the Kidney of Diabetic Rats.

Diabetic nephropathy is one of the major diabetic complications which has become the major cause of end-stage renal disease. It has been demonstrated that apoptosis induced by hyperglycemia is a critical factor in the pathophysiology of diabetic nephropathy. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The protective effect of taurine against apoptosis in diabetic kidney deserves to be explored. In the present study, mRNA expression of cysteinyl aspartate-specific proteinase-3 (caspase-3) and caspase-9 was examined, and the activity of caspase-3 was also detected as the marker of apoptosis. The expression of Bax and Bcl-2 was detected by Western blot. In addition, the level of total Akt and phosphorylated Akt (p-Akt) was measured. We found that caspase-3 and caspase-9 mRNA expression was decreased in diabetic kidney, which was recovered by taurine treatment. The activity of caspase-3 was increased in diabetic kidney, while the increased activity was significantly attenuated after taurine treatment. We also found that the expressions of Bax and Bcl-2 were disturbed in diabetic kidney, which were reversed by taurine treatment. The decrease of the p-Akt level was also prevented by taurine treatment. These results indicated that taurine-ameliorated apoptosis in diabetic kidney may be through activating of the Akt signaling pathway.