内皮素A受体在oxLDL促血管平滑肌细胞增殖中的作用

Effect of endothelin subtype A receptor in vascular smooth muscle cells proliferation evoked by oxidized low-density lipoprotein

目的:研究氧化低密度脂蛋白(oxLDL)对培养血管平滑肌细胞(VSMC)增殖中内皮素受体A亚型(ETRA)mRNA表达水平的影响。方法:Cu2+氧化法制备oxLDL,观察oxLDL对大鼠主动脉VSMC增殖和ETRAmRNA表达的影响。将VSMC用非肽类ETRA拮抗剂BMS-182874预处理后,加入10μg/mloxLDL温育24h。采用非核素MTS吸光度法测定细胞增殖,RNA印迹法检测ETRAmRNA水平。结果:低浓度oxLDL促进VSMC增殖,高浓度引起细胞毒作用;oxLDL升高ETRAmRNA水平;ETRA拮抗剂BMS-182874明显抑制oxLDL引起的增殖作用。结论:动脉粥样硬化形成中有ETRA参与,ETRA拮抗剂可能具有临床应用价值。

Objective: To investigate the effects of endothelin and its receptors in the proliferation of vascular smooth muscle cells (VSMC) in the intima of arteries stimulated by oxidized low density lipoprotein (oxLDL). Methods: Aortic rabbit SMC were grown in 20% and then 0.5% newborn calf serum. Then cells were incubated with different concentrations of LDL or oxLDL (oxidation of LDL was induced by incubation with Cu 2+ ) for 24 h, and pretreated with different concentrations of selective non peptide ETR A antagonist BMS 182874 followed by incubation with 10 μg/ml oxLDL for 24 h. Cell proliferation was measured by non radioactive MTS absorbance at 490 nm. ETR A mRNA expression levels of VSMC incubated with oxLDL were also performed by Northern blot. Results: Low levels of oxLDL had significantly proliferative effect on VSMC, while high levels of which had cytotoxic effect. oxLDL increased ETR A mRNA expression levels of VSMC. BMS 182874 significantly inhibited the proliferative response of VSMC evoked by oxLDL. Conclusion: ETR A may be involved in atherogenesis. Selective non peptide ETR A antagonist BMS 182874 may potentially have clinical implication.