Testosterone suppresses rat vascular smooth muscle cell phenotypic transition and proliferation / 中华内分泌代谢杂志

ABSTRACT

Objective To investigate the inhibitory effect of testosterone on oxidized low-density lipoproteins ( ox-LDL)-stimulated phenotypic transition and proliferation of vascular smooth muscle cells ( VSMCs) in vitro, and to explore its possible mechanisms. Methods Rat VSMCs cultured in vitro were divided into control group, ox-LDL group(50μg/mlox-LDL),fetalbovineserum(FBS)group(10% FBS),andtestosteronegroups(5×10-8 or5×10-7 mol/L testosterone plus 50μg/ml ox-LDL) . The effect of testosterone on ox-LDL-induced proliferation of VSMCs was explored by WST-1 assay. The cell cycle distribution was determined using flow cytometry. Western blotting was used todetecttheexpressionsofmitofusin2(Mfn2),phosphorylatedextracellularsignal-regulatedkinases1/2(p-ERK1/2) , proliferating cell nuclear antigen ( PCNA) ,α-smooth muscle actin (α-SMA) ,and osteopontin ( OPN) . Results Compared with control group, the proliferation of VSMCs was promoted by ox-LDL, the number of VSMCs decreased in G0/G1 phase and increased in S phase significantly, the expression levels of Mfn2 and α-SMA were significantly reduced, and the expression levels of p-ERK1/2, PCNA, and OPN were significantly raised in ox-LDL group. Compared with ox-LDL group, the proliferation of VSMCs was inhibited, the number of VSMCs increased in G0/G1 phase and decreased in S phase in two testosterone groups, along with the increased expressions of Mfn2 andα-SMA, and the descended expressions of p-ERK1/2, PCNA, and OPN. Conclusions Testosterone inhibits phenotypic transition and proliferation of VSMCs induced by ox-LDL in vitro, which may be related to the up-regulated expression of Mfn 2 and the suppression of ERK1/2 pathway.