大鼠蛛网膜下腔出血迟发性脑血管痉挛血小板衍生生长因子基因表达动态变化

Dynamic alteration of gene expression of the platelet-derived growth factor on SAH with late responseive cerebral vasospasm in rat

目的 探讨血小板衍生物因子 (PDGF)在蛛网膜下腔出血后迟发性脑血管痉挛(DCVS)发病中的作用。 方法 采用RT PCR和免疫组化方法检测PDGFmRNA在大鼠SAH后DCVS脑组织中基因转录和蛋白表达变化。 结果 正常对照及SAH后 30minPDGFmRNA的转录表达水平均很低 ,注血 3d后PDGFmRNA转录水平显著上调 ,较正常对照增强 (P <0 0 1) ,以血管为最强 ;注血 7d后PDGFmRNA转录水平仍高于正常对照组 (P <0 0 1) ;仍以血管为最强 ,次为海马、皮质及基底节区。免疫组化染色显示注血 3d后在皮质、海马、基底节、室管膜、血管均可见PDGF B免疫染色阳性细胞明显增多 ;注血 7d后海马CA1、CA2、CA3及齿状回神经细胞染色为强阳性 ,皮质、基底节阳性细胞数增多 ,阳性染色深度增强。各部位血管 ,特别是脑底部大动脉明显增生 ,管壁增厚 ,PDGF B强阳性反应。免疫组化结果经图像分析 ,注血 3d后和 7d后PDGF B阳性染色明显高于正常对照组及注血 30min组 (P <0 0 1) ,海马及血管亦高于皮质、基底节。 结论 PDGFmRNA转录和PDGF B蛋白表达增强与SAH后DCVS的血管增生性变化有关 ,可能是SAH后DCVS及其所致的迟发性神经功能缺损的原因之一。

Objective To investigate the effect of platelet-derived growth factor(PDGF) in DCVS diseases after SAH. Methods Alteration of PDGF gene and mRNA expression in DCVS brain tissues after SAH by RT-PCR and immunohistochemistry. Results To compare with the control group, transcription level of PDGF mRNA up-regulated evidently 3 days after transfusion (P<0.01) and kept in high level until 7 days after transfusion. Meanwhile it was tested by immunohistochemistry that the control group and group treated for 30 minute after transfusion displayed weak positive PDGF and interspersed in neural cells and neuroglia cells, but blood vessel not positively and evidently stained. PDGF positive cells of cortex, hippocampi, basal ganglia, ependyma and blood vessel increased evidently 3 days after transfusion. PDGF-B stained cell of hippocampi CA1, CA2, CA3 and dentate gyrus were strongly positive, blood vessles of the above areas proliferated obviously and were more in hippocampus and blood vessles than in cortex and basal ganglia 7 days after transfusion. Conclusions Enhancement of PDGF expression are related with the pathologic hypertrophic alteration of DCVS blood vessel, and it might be one the causes of the DCVS and the resulted delayed neurofunctional deficiency after SAH.