致动脉粥样硬化不同因素对大鼠腹腔巨噬细胞和主动脉平滑肌细胞分泌表达Tenascin-C的影响

Effects of atherosclerosis-stimulating factors on Tenascin-C expression in rat aortic smooth muscle cells and peritoneal macrophages

目的 观察一些致动脉粥样硬化因素对培养的大鼠腹腔巨噬细胞和主动脉平滑肌细胞分泌表达Tenascin C的影响。方法 体外分离培养大鼠腹腔巨噬细胞和主动脉平滑肌细胞 ,同步后分别加入不同刺激因子采用Westernbolt及逆转录聚合酶链反应 (RT PCR)的方法检测Tenascin C蛋白和mRNA水平表达。结果 Tenascin C在两种细胞的对照组中均不表达 ,低密度脂蛋白刺激组只有少量表达 ,其余各刺激组均呈高水平表达。加入氧化修饰低密度脂蛋白 (oxLDL) 2h后即有Tenascin C的表达 ,6h时达高峰 ,可持续到 2 4h。oxLDL与Tenascin C蛋白的表达呈明显的浓度依赖性。结论 oxLDL等致动脉粥样硬化刺激因子可在转录水平上调Tenascin C基因的表达 ,从而促进血管平滑肌细胞和巨噬细胞分泌表达高水平的Tenascin C ,这可能是动脉粥样硬化中Tenascin

Objective To observe the effects of some atherosclerosis-stimulating factors on Tenascin-C expression in rat ao rtic smooth muscle cells and peritoneal macrophages.Methods The in vitro cultured rat aortic smooth muscle cells and peritoneal macrophages were harvested. The effects of stimulating factors on expression of Tenascin-C protein and mRNA in these cells were examined by Western blot and RT-PCR respectively.Results Tenascin-C was not detected in control group and only little expression was observed in low density lipoprotein stimulated group, but it was strongly upregulated in other simulated groups. Oxidized low density lipoprotein caused a dose-dependent progressive increase in steady-state levels of Tenascin-C protein in stimulated rat vascular smooth muscle cells and peritoneal macrophages. RT-PCR analysis showed that Tenascin-C mRNA levels increased within 2 hours of exposure to oxidized low density lipoprotein, reached a peak level of about 3-fold above control by 6 hours, and remained elevated for 24 hours.Conclusion Oxidized low density lipoprotein may regulate the expression of Tenascin-C gene at transcription level and increased the expression of Tenascin-C in rat vascular smooth muscle cells and macrophages.This may be the main reason of accumulation of Tenascin-C in atherosclerotic lesion.