The antagonistic effect of selenium on lead-induced apoptosis via mitochondrial dynamics pathway in the chicken kidney

Abstract

Selenium (Se) is known to have antagonistic effects against lead (Pb) toxicity in animal. The aim of this study was to evaluate the roles of mitochondrial dynamics on Pb-induced apoptosis in the chicken kidney and investigate the antagonistic effect of Se. In the present study, brown layer chickens were randomly allocated to four groups, and each group were exposed to a basic diet (0.2 mg kg^-1 Se and 0.5 mg kg^-1 Pb), a Se-adequate diet (1 mg kg^-1 Se and 0.5 mg kg^-1 Pb), a Se and Pb compound diet (1 mg kg^-1 Se and 350 mg kg^-1 Pb) or a Pb supplemented diet (0.2 mg kg^-1 Se and 350 mg kg^-1 Pb). On the 90^th day, the kidney was removed to determine the activities of mitochondrial respiratory chain complexes, ATPases and oxidative indexes. The expression levels of mitochondrial dynamics and apoptosis-related genes were also determined. The results showed that Pb treatment significantly decreased the activities of mitochondrial complexes and ATPases, and increased oxidative stress, and mitochondrial dynamics and anti-apoptosis-related genes had a lower expression, whereas mitochondrial pro-apoptosis related genes presented higher expressions in the Pb group compared with control group (P < 0.05). However, the co-treatment of Se and Pb significantly alleviated those changes compared with the Pb group (P < 0.05). In conclusion, we speculated that Pb could increase the oxidative stress and promote the apoptosis via regulating mitochondrial dynamics and apoptosis-related genes, and Se exhibited antagonistic roles against the Pb-induced apoptosis in the kidney of chickens.

Keywords: Apoptosis; Kidney; Lead; Mitochondrial dynamics; Selenium.