Lentivirus-mediated RNA Interference Targeting I2PP2A Attenuated Trichloroethylene-induced Cytotoxicity in Human L-02 Liver CeUs

摘要

Occupational exposure to trichloroethylene (TCE) could cause severe hepatotoxicity. However, the mechanisms of hepato-toxicity caused by TCE remained poorly understood. We have reported by proteomic study that TCE up-regulated the expression of the inhibitor 2 of protein phosphatase 2A (I2PP2A) in human L-02 liver cells. In order to further determine the potential role of I2PP2A in TCE-induced toxicity, we used the techniques of siRNA, Westem-blot analysis, protein phosphatase activity and apoptosis assay to explore whether I2PP2A is involved in TCEinduced cytotoxicity in L-02 liver cells. First, we constructed L-02 cells stably expressing shRNA against I2PP2A by using lentivirus transfection, and found that the activity of PP2A in the stable I2PP2A siRNA L-02 cells was increased by approximately 20% compared to the control cells. We treated the L-02 cells and the stable I2PP2A siRNA L-02 cells with 2. 0mol/L for 24h and found that increased apoptosis caused by TCE were partially attenuated in the stable I2PP2A siRNA L-02 cells. The inhibition of PP2A activity as well as increased activity of casapse-3 induced by TCE in L-02 cells was both partially reversed in the stable I2PP2A siRNA L-02 cells. These data for the first time demonstrated that upregulation of I2PP2A could mediate, at least in part, TCE-induced hepatotoxicity through inhibition of PP2A activity and caspase-3-mediated pathway, and suggested that I2PP2A could be a crucial molecule leading to TCE hepatotoxicity.