Homocysteine promotes rat VSMCs proliferation and phenotypic transformation

AIM: To provide evidence for the molecular mechanism of homocysteine (Hcy) as an independent risk factor in atherosclerosis (AS) by investigating the effect of Hcy on phenotype transformation and proliferation of vascular smooth muscle cells(VSMCs) in rats. METHODS: After treated with different concentrations of Hcy for 24 h, the cultured VSMCs were assayed for cell proliferation rate by MTT method, cell cycle by flow cytometry, the expression of SM22-α mRNA by semi-quantitative RT-PCR and the observation of morphological characteristics and the phenotype transformation by transmission electron microscopy.RESULTS: Hcy increased the cell proliferation rate and gradually reduced the proportion of the cells in G0/G1 phase. Hcy down-regulated the expression of SM22α mRNA and the most significant effect was observed at concentration of 1 000 μmol/L. The observations of transmission electron microscopy revealed an abundant endoplasmic reticulum, Golgis complex, loose nucleus and puffy chromatin in VSMCs treated with high concentration of Hcy. CONCLUSION: Hcy promotes the proliferation and phenotype transformation of VSMCs simultaneously.