Regulation of taurine in OTA-induced apoptosis and autophagy

Abstract

Ochratoxin A (OTA), one of the most deleterious mycotoxins, could cause a variety of toxicological effects especially nephrotoxicity in animals and humans. Taurine, a wide-distributed cytoprotective amino acid, plays an important role as a basic factor for maintaining cellular integrity homeostasis. However, the potential effect of taurine in OTA-induced nephrotoxicity remains unknown. In the present study, we demonstrated that OTA treatment at 4.0-8.0 μM increased apoptosis in PK-15 cells as shown by increased the ratio of apoptosis and protein expression of Bax and cleaved-caspase-3, decreased protein expression of Bcl-2. Meantime, OTA treatment triggered autophagy, as indicated by markedly increased the protein expression of LC3-II and fluorescence intensity of GFP-LC3 dots. Taurine supplementation decreased OTA-induced cytotoxicity and attenuated apoptosis as shown by the decreased Annexin V/PI staining and the decreased expression of apoptosis-related proteins including Bax and caspase-3. Meanwhile, taurine attenuated OTA-induced autophagy by decreased the protein expression of LC3-II and fluorescence intensity of GFP-LC3 dots to maintain cellular homeostasis. In conclusion, taurine treatment could alleviate OTA-induced apoptosis and inhibit the triggered autophagy in PK-15 cells. Our study provides supportive data for the potential roles of taurine in reducing OTA-induced renal toxicity.

Keywords: Apoptosis; Autophagy; Ochratoxin A; PK-15; Taurine.