同型半胱氨酸对大鼠血管平滑肌细胞增殖及胶原生成的影响

目的了解同型半胱氨酸(Hcy)的浓度与Ⅰ、Ⅲ、Ⅳ和Ⅵ型胶原的产生有无联系以及对大鼠血管平滑肌细胞(VSMC)增殖效应的影响。方法实验分为对照组,不同Hcy浓度组和空白孔组,用不同的Hcy浓度刺激VSMC,在不同的时间点以四甲基偶氮唑盐活细胞染色法检测Hcy对VSMC的活性影响;以5溴-2脱氧尿苷法检测Hcy对VSMC的DNA合成的作用及流式细胞仪观察细胞周期的变化;酶联免疫吸附法测定胶原的含量。结果在0.025-0.05 mmol/L的Hcy浓度刺激下,12-48 h VSMC增殖增加明显;流式细胞仪分析发现增殖细胞S期的百分含量较对照组和Hcy其他浓度组明显增加。细胞的Ⅰ型和Ⅳ型胶原分泌随着Hcy浓度的升高呈现剂量依赖性的增高模式。Ⅲ型胶原亦呈现轻度的升高,但无显著性意义。高浓度的Hcy会减少Ⅵ型胶原的分泌,并呈剂量依赖性。结论较低浓度的Hcy能使VSMC增殖加速,且Hcy导致了细胞分泌胶原类型及模式的改变,最终加速了粥样斑块的发生和发展。

Effects of homocysteine on proliferation and production of collagen in rat vascular smooth muscle cells

Objective To investigate the relationship between concentration of Hcy and production of collagen types Ⅰ,Ⅲ,Ⅳ,Ⅵ and cell proliferation.Methods Rat vascular smooth muscle cells(VSMCs) were treated with different concentrations of Hcy at different time points.Cell viability was evaluated by MTT,cell proliferation by BrdU and flow cytometery.Collagen was measured by ELISA.Results VSMCs in cultures proliferated significantly at Hcy concentrations of both 0.025 mmol/L and 0.5 mmol/L.Collagen types I and Ⅳ increased significantly in a dose-dependent manner with increasing concentrations of Hcy.Collagen type Ⅲ also increased,but had no statistical significance.The amount of type Ⅵ collagen was significantly reduced in a dose-dependent manner.Conclusion The present observation suggests that low concentration of Hcy can stimulate VSMCs to proliferate rapidly,meanwhile Hcy may contribute to accelerated progression of atherosclerotic lesions with collagen alteration which transforms the injury into fibrotic plaque.