Effects of adenovirus-mediated shRNA targeting PTEN on proliferation and apoptosis of activated hepatic stellate cells in vitro

AIM:To investigate the down-regulation of phosphatase and tensin homolog deleted on chromosome 10(PTEN) gene by adenovirus-mediated short hairpin RNA(shRNA) on proliferation and apoptosis of activated hepatic stellate cells(HSCs) in vitro and the related signaling transduction pathways. METHODS:The activated HSCs were cultured in vitro and transfected with recombinant adenovirus expressing shRNA targeting PTEN. The proliferation of HSCs was measured by MTT assay and the apoptosis was assessed by TUNEL and flow cytometry. Western blotting was used to detect the protein levels of PTEN, Bax, Bcl-2, Akt, p-Akt, ERK1/2 and p-ERK1/2 in HSCs, and real-time fluorescent quantitative PCR was applied to detect the mRNA expression of Akt and ERK1. RESULTS:The recombinant adenovirus expressing shRNA targeting PTEN was successfully transfected into activated HSCs in vitro, and significantly promoted the proliferation of HSCs in a time-dependent manner within a certain extent. The apoptotic rate of HSCs was significantly decreased 72 h after transfection(P<0.05). Meanwhile, reduced expression of Bax and elevated expression of Bcl-2 were induced 72 h after transfection(P<0.05). Furthermore, the expression of p-Akt and p-ERK1/2 were increased significantly(P<0.05), while no significant difference in the expression of Akt and ERK1 at mRNA and protein levels was observed(P>0.05). CONCLUSION:Down-regulation of PTEN by adenovirus-mediated shRNA dramatically promotes the proliferation of activated HSCs, and inhibits the apoptosis through Bcl-2/Bax pathway. In addition, the phosphorylation of Akt and ERK1/2 is increased, indicating that PI3K/Akt and ERK1/2 signal transduction pathways may play an important role in the regulation of proliferation and apoptosis of HSCs.