tMfn 2 gene induces apoptosis of vascular smooth muscle cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Mitofusin2 (Mfn2) profoundly inhibits proliferation and induces apoptosis of vascular smooth muscle cells (VSMCs) through phosphatidylinositol 3 kinase/protein kinase B. Notably, tMfn2, with the transmembrane domain deleted, has a 41%-reduced molecular weight, which possibly exhibits a stronger effect on inducing apoptosis.OBJECTIVE: To investigate the effect of rat tMfn2 gene, with the transmembrane domain deleted, on promoting the apoptosis of VSMCs, and to determine related signal pathway.DESIGN, SETTING AND TIME A controlled observational study at a gene level was performed in the central laboratory, Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology between January and October in 2008.MATERIALS Rat VSMCs and the recombinant adenovirus containing LacZ, Mfn2 or tMfn2 was offered by Professor Chen as a gift.METHODS: The rat VSMCs cultured at 3-10 passages were divided into 4 groups. ①Blank control group No interventions. ② VSMCs were infected by adenovirus-mediated LacZ, Mfn2, and tMfn2, respectively.MAIN OUTCOME MEASURES: ①Expressions of Mfn2 and tMfn2 following the VSMCs were infected with recombinant adenovirus for 24 hours. ②The apoptosis of VSMCs was determined with flow cytometry and enzyme linked immunosorbent assay at 24, 48 and 72 hours following infection. ③Western blot was used to analyze the expression of phosphorylated AKT following the VSMCs were infected with recombinant adenovirus for 24 hours.RESULTS: ①Both Mfn2 and tMfn2 were expressed in the VSMCs. ②The tMfn2 was superior to Mfn2 in promoting the apoptosis of VSMCs in a time-dependent manner (P<0.01). ③The protein expression of phosphorylated AKT remarkably decreased two groups, especially significant in tMfn2-infected group (P<0,01).CONCLUSION: The tMfn2 can induce the apoptosis of VSMCs more effectively via the inhibition of phosphorylated AKT signaling pathway.