The Apoptosis Induced by PIG11 Protein in HepG2 Cells and the Discussion of its Mechanism

Objective Explore the effect of PIG11 gene expression on HepG2 cell line apoptosis with HepG2 cells line high expressing PIG11 gene.Mitochondrial dysfunction were researched to get the more information of apoptotic mechanism induced by PIG11.Methods The role of PIG11 in apoptosis was analyzed by the flow cytometer scans(FACS).Apoptotic cells were quantified by sub-G1DNA content.The fluorescent probe rhodamine 123 was used to analyze the mitochondrial transmembrane potential(Δψm) and the cellular fluorescence intensity was measured by FACS.Cytochrome C(Cyt C) protein was analyzed by western blot.Results Rh 123 fluorescence showed a decrease in pLXSN-PIG11-HepG2 cells(5.4±0.15),compared with HepG2 cells(14.7±0.56)and pLXSN-HepG2 cells(13.2±0.53)(P0.01),suggesting a loss of the Δψm in pLXSN-PIG11-HepG2 cells.The apoptosis was blocked visibly by CsA(an effective and specific inhibitor of mitochondrial permeability transition pore,mtPTP).Cyt c content extracted from HepG2 cells with pLXSN-PIG11 was decreased considerably in the mitochondria,whereas it increased in the cytosol.These demonstrated that loss of Δψm with the release of Cyt c in the apoptosis induced by PIG11.Conclusion These findings suggest that over-expression of PIG11 induce HepG2 cells apoptosis through mitochondrial pathway.