Non-cytotoxic concentrations of acetaminophen induced mitochondrial biogenesis and antioxidant response in HepG2 cells

Publication date: Available online 1 July 2016 Source:Environmental Toxicology and Pharmacology Author(s): Tingfen Zhang, Qiang zhang, Jiabin Guo, Haitao Yuan, Hui Peng, Lan Cui, Jian Yin, Li Zhang, Jun Zhao, Jin Li, Andrew White, Paul L. Carmichael, Carl Westmoreland, Shuangqing Peng Mitochondrial dysfunction has been implicated in acute, severe liver injury caused by overdose of acetaminophen (APAP). However, whether mitochondrial biogenesis is involved is unclear. Here we demonstrated that mitochondrial biogenesis, as indicated by the amounts of mitochondrial DNA and proteins, increased significantly in HepG2 cells exposed to low, non-cytotoxic concentrations of APAP. This heightened response was accompanied by upregulated expression of PGC-1α, NRF-1 and TFAM, which are key transcriptional regulators of mitochondrial biogenesis. Additionally, antioxidants including glutathione, MnSOD, HO-1, NQO1, and Nrf2 were also significantly upregulated. In contrast, for HepG2 cells exposed to high, cytotoxic concentration of APAP, mitochondrial biogenesis was inhibited and the expression of its regulatory proteins and antioxidants were concentration-dependently downregulated. In summary, our study indicated that mitochondrial biogenesis, along with antioxidant induction, may be an important cellular adaptive mechanism counteracting APAP-induced toxicity and overwhelming this cytoprotective capacity could result in liver injury.

Source: Environmental Toxicology and Pharmacology - July 1, 2016 Category: Environmental Health Source Type: research