溶血磷脂酸受体3介导溶血磷脂酸诱导的血管平滑肌细胞表型转化

目的探讨溶血磷脂酸(LPA)受体在LPA诱导的血管平滑肌细胞(VSMC)表型转化中的作用及相关信号传导通路。方法培养SD大鼠分化表型VSMC,培养液加胰岛素样生长因子(IGF-1)为IGF-1组,加溶剂载体为空白组,以不同浓度水平LPA(0.1～10μmol/L)刺激,依次为LPA 0.1组、LPA 1组和LPA 10组,并在LPA(1μmol/L)条件下,以LPA受体1,3拮抗剂二辛烷甘油焦磷酸盐(DGPP 8:0)为DGPP 1组,RT-PCR法检测平滑肌肌动蛋白α(SMA-α)和骨桥蛋白mRNA表达,Western blot法检测p38分裂原活化蛋白激酶(p38MAPK),细胞外信号调节激酶(ERK)及其磷酸化蛋白水平。结果与空白组和IGF-1组比较,LPA 0.1组、LPA 1组和LPA 10组呈剂量依赖促进骨桥蛋白mRNA表达上升,SMA-αmR NA表达下降(P<0.01);与空白组比较,LPA 1组p38MAPK和ERK激活(P<0.01),DGPP 1组p38MAPK和ERK无明显变化(P>0.05)。结论与Gq蛋白偶联的LPA受体3介导了LPA诱导的VSMC表型转化,阻滞上述通路有可能成为控制与动脉粥样硬化和再狭窄等血管疾病相关的VSMC表型转化潜在的治疗干预靶点。

LPA receptor 3 mediates LPA-induced phenotype transformation of vascular smooth muscle cells

Objective To study the role of lysophosphatidic acid(LPA) receptors in LPA-induced phenotype transformation of vascular smooth muscle cells(VSMC) and its related signaling pathways. Methods Differentiated phenotypes of VSMC from SD rats were cultured.Cultured fluid containing IGF-1 served as an IGF-1 group and cultured fluid containing solvent carrier served as a control group.Different LPA concentrationsCO.1—10 jumol/L)-stimulated VSMC were divided into LPA 0.1 group,LP A 1.0 group,and LPA 10 group.LPA-1 and LPA-3 receptor 1 antagonist DGPP 8:0 1μmol/L served as DGPP 1 group.Expressions of LPA receptors,SMA-a and osteopontin mRNA were detected by RT-PCR.Expressions of p38MAPK and ERK and its phosphorylated protein were detected by Western blot.Results The expression level of osteopontin mRNA in VSMC was higher while the expression level of SMA-a was lower in LPA 0.1,LPA 1 and LPA 10 groups than in control group and IGF-1 group,the expression of p38MAPK and ERK was significantly higher in LPA 1 group than in control group(P<0.01).No significant difference was found DGPP 1 group and control group(P>0.05).PTX had no effect on phenotype transformation of VSMC.Conclusion LPA receptor 3 coupled with Gq protein mediates LPA-induced phenotype transformation of VSMC.Blocking these pathways may become the potential intervention target for the control of vascular diseases-related phenotype transformation of VSMC.