海分枝杆菌感染活化星形胶质细胞对VEGFA表达的研究

Astrocyte activation of VEGFA by priming signals derived from macrophages infected with mycobacteria

目的研究分枝杆菌感染巨噬细胞后的条件培养基活化星形胶质细胞表达血管内皮生长因子A(VEGFA)作用及其可能的机制。方法用海分枝杆菌感染小鼠腹腔巨噬细胞后的条件培养基感染星形胶质细胞,采用qRT-PCR及ELISA检测VEGFA mRNA和VEGFA蛋白的表达情况,采用Western blot检测低氧诱导因子(hypoxia inducible factor,HIF-1α)的表达,ELISA检测加入HIF-1α抑制剂后VEGFA的表达。结果海分枝杆菌感染巨噬细胞后的条件培养基能活化星形胶质细胞,并在感染后12h^24h诱导HIF-1α明显表达,同时随着感染时间的延长,VEGFA表达逐渐增多,24h达到峰值。使用HIF-1α的抑制剂不能完全阻断VEGFA的合成。结论 HIF-1α可能参与分枝杆菌感染后星形胶质细胞表达VEGFA,且还可能有其他转录因子参与这一过程。

Objectives To explore the effects that conditioned media from cultured macrophages infected with Mycobacterium marinumhad on expression of Vascular endothelial growth factor A（VEGFA）in primary murine astrocytes and the mechanisms for that action. Methods Astrocytes were treated with media from mouse peritoneal macrophages（MPM）that had been infected with M.marinumand cultured for different lengths of time.VEGFA mRNA and protein were quantified using qRT-PCR and enzyme-linked immunosorbent assay（ELISA）with or without use of hypoxia inducible factor（HIF）-1αinhibitor.HIF-1αexpression was detected using Western blotting. Results Twelve to 24 hafter macrophages were infected with M.marinum,media from cultured macrophages markedly induced HIF-1αin astrocytes.Significant VEGFA biosynthesis was observed 6hafter infection and the maximum response occurred 24 hafter infection.HIF-1αinhibitor did not markedly affect VEGFA expression. Conclusion There are other transcription factors besides HIF-1αthat mediate VEGFA expression in astrocytes treated with media from cultured macrophages infected with M.marinum.