Effects of PRELI in Oxidative-Stressed HepG2 Cells.

Protein of relevant evolutionary and lymphoid interest (PRELI) is known for preventing apoptosis by mediating intramitochondrial transport of phosphatidic acid. However, the role of PRELI remains unclear. This study has demonstrated functions of PRELI through PRELI-knockdown in hepatocellular carcinoma (HepG2) cells exposed to oxidative stress by hydrogen peroxide. Results show that PRELI has three functions in HepG2 cells with regard to oxidative stress. First, PRELI affects expressional regulation of SOD-1 and caspase-3 genes in HepG2 cells. PRELI knockdown HepG2 cells have shown up-regulation of caspase-3 and down-regulation of SOD-1. Second, PRELI suppresses mitochondrial apoptosis in HepG2 cells. Fluorescence intensity related to mitochondrial apoptosis in PRELI-knockdown HepG2 cells increased more than two-fold compared to normal HepG2 cells. Third, PRELI suppresses senescence of HepG2 cells with oxidative stress. PRELI knockdown HepG2 cells showed higher levels of senescence than normal HepG2 cells. These results suggest that PRELI is a crucial protein in the suppression of apoptosis in HepG2 cells in response to oxidative stress.