溶血磷脂酸通过蛋白激酶C-α/钙离子途径促进大鼠星形胶质细胞增殖

目的：了解溶血磷脂酸（LPA）对星形胶质细胞（AS）活化增殖的影响及其作用机制。方法:原代培养的新生SD大鼠前脑星形胶质细胞分为对照组、PKC-α激动剂（PMA）组、LPA组、PKC-α抑制剂（Ro31-8220）组、Ro31-8220＋PMA组和Ro31-8220＋LPA组，用二苯基四氮唑溴盐（MTT）比色法以及流式细胞仪（FCM）检测AS增殖。以Fura－2/AM标记细胞内钙离子，紫外分光光度计检测其浓度。用蛋白印迹法检测细胞内PKC-α表达。结果:LPA和PMA能明显促进AS的增殖，并增加细胞内PKC-α的表达以及细胞内钙离子（［Ca2+］i）浓度（P<0.01）；Ro31-8220预处理后，显著缓解LPA促AS增殖程度和［Ca2+］i浓度的增加（P<0.01），［Ca2+］i浓度的变化与PKC-α表达量的变化呈正相关。结论:LPA通过PKC-α/Ca2+途径促进AS的增殖活化。

Lysophosphatidic acid (LPA) induces the proliferation of astrocytes in rat via pathway of protein kinase C -α and calcium ion in vitro

AIM: To determine if lysophosphatidic acid (LPA) regulates the proliferation of astrocytes (AS) and to approach the mechanism of the process.METHODS: The cerebral AS of the neonatal SD rats were cultured in vitro and divided randomly into control group, PKC excitomotor (PMA) group, LPA group, PKC-α inhibitor (Ro31-8220) group, Ro31-8220+PMA group and Ro31-8220+LPA group. The proliferation of the cells was detected by MTT assay and flow cytometry (FCM). The concentration of intra-cellular calcium ion of the cells (［Ca2＋］i) which were labeled with Fura-2/AM was determined by ultraviolet spectrophotometer. The change of PKC-α inside the cells was observed by Western blotting.RESULTS: LPA and PMA stimulated the proliferation of AS, they also enhanced the expression of PKC-α and increased the concentration of ［Ca2＋］i. After pretreated with Ro31-8220, the abilities of LPA that mentioned above were decreased. The change of ［Ca2＋］i was associated with the diversity of PKC-α.CONCLUSION: LPA promotes the proliferation of AS via the way of PKC-α and Ca2＋.