Mitochondrial respiratory chain damage and mitochondrial fusion disorder are involved in liver dysfunction of fluoride-induced mice

Our previous study showed that excessive fluoride (F) intake can induce liver dysfunction. The aim of this study was to investigate the mechanisms of F-induced mitochondrial damage resulting in liver dysfunction. Damaged mitochondrial ultrastructure and state of liver cells were estimated by TEM, TUNEL staining and BrdU measurement. The ROS level and ATP content in the liver tissue were measured by ELISA kit. Meanwhile, optic atrophy (OPA1), mitofusin-1 (Mfn1), NDUFV2, SDHA, CYC1, and COX Ⅳ expression levels were measured through real-time PCR and Western-blot. Results showed that the ROS level increased, thereby resulting in mitochondrial ultrastructure damage and abundant liver cells presented evident apoptotic characteristics after F treatment. Decreased ATP content and the abnormal expression of OPA1, Mfn1, NDUFV2, SDHA, CYC1, and COX Ⅳ of the liver tissue were observed. In conclusion, excessive F-induced mitochondrial respiratory chain damaged and mitochondrial fusion disorder resulted in liver dysfunction.