碱性成纤维细胞生长因子对脑微血管内皮细胞血管新生基因谱和环加氧酶-2表达的影响

本文研究了碱性成纤维细胞生长因子（basic fibroblast growth factor, bFGF）对小鼠脑微血管内皮细胞（microvascular endothelial cell, MVEC）株bEnd．3中血管新生相关基因表达谱的改变,并重点从mRNA、蛋白质和细胞水平检测bFGF对血管新生旁观分子环加氧酶-2（cyclooxygenase-2,COX-2）表达的影响。用特异性小鼠血管新生基因芯片高通量检测bEnd．3细胞基因谱表达的改变,分析促血管新生基因及抑制血管新生的基因表达谱的变化;用RT—PCR、Western blot、免疫细胞化学等方法分别从mRNA、蛋白质和细胞水平检测COX-2表达变化及细胞内的定位。结果发现用10ng／ml的bFGF刺激bEnd．3细胞2h后多种促血管新生基因表达明显上调,如Adamtsl、MMP-9、Ang-1、PDGFB、G—CSF、FGFl6、IGF-1等分别上调3、8、120、5．2、4．5、1．7、2．7倍。与此同时,多种抑制血管新生的基因表达相应下调,如TSP-3、TIMP-2、TGFβ1等表达分别下调3．4、1．5和3．5倍。RT-PCR和Western blot的结果证实,bFGF可以上调COX-2mRNA的表达和蛋白质的合成。免疫组化的结果表明,COX-2主要分布在胞浆。以上结果提示：bFGF具有上调促血管新生基因表达,下调抑制血管新生基因表达的作用,两者协同作用,促进血管新生。同时bFGF还可以明显促进血管新生旁观分子COX-2mRNA的表达和蛋白质的合成。本文讨论了bFGF引起MVEC内COX-2表达上调的意义。

Effects of basic fibroblast growth factor on the expressions of angiogenic gene profile and cyclooxygenase-2 in brain microvascular endothelial cells

The present study aimed to investigate the effects of basic fibroblast growth factor (bFGF) on the expressions of angioge-nesis-related genes in a mouse brain microvascular endothelial cell line, namely bEnd.3, using cDNA microarray. The effects of bFGF (10 ng/ml) on mRNA and protein expressions of cyclooxygenase-2 (COX-2), an angiogenesis bystander molecule, were further investigated. cDNA microarray was employed to study the effects of bFGF on the expressions of angiogenic genes in a high throughput pattern. RT-PCR was used to study the effect of bFGF on COX-2 mRNA expression. Western blot and immunocytochemistry were utilized to study the effect of bFGF on COX-2 protein expression. The results showed that, 2 h after bFGF treatment, pro-angiogenic genes (Adamtsl, MMP-9, Ang-1, PDGF B, G-CSF, FGF16, IGF-1, etc.) were significantly upregulated, whereas anti-angiogenic genes (TIMP-2. TSP-3, etc.) were significantly downregulated. The bystander molecule in angiogenic pathway COX-2 mRNA and protein expressions were significantly upregulated after bFGF treatment. It is suggested that triggering angiogensis switch through upregulating pro-angiogenic gene and downregulating anti-angiogenic gene expression is one of the major mechanisms of bFGF-induced angiogenesis. The expression change of COX-2, as a bystander molecule, was observed after bFGF treatment in bEnd.3 cells and the significance was discussed.