【摘要】 目的探讨人类神经前体细胞中内源性人端粒酶反转录酶(hTERT)基因的转录活性及增殖与分化相关调控机制。方法采用系列hTERT基因启动子的荧光素酶报告载体和β-半乳苷酶表达载体,瞬时共转染HeLa细胞和hNPCs-G3细胞,检测不同长度启动子的活性。分析碱性成纤维细胞生长因子(bFGF)促进增殖过程中hTERT基因启动子活性,分析cAMP诱导分化过程中hTERT基因启动子活性。结果 hNPCs-G3神经前体细胞内源性hTERT基因的转录活性较低,主要依赖近端启动子区。bFGF上调hNPCs-G3神经前体细胞内源性hTERT基因的表达,其调控主要作用在-2 098～-1 099bp区域和-3 216bp～-2 098bp区域内;cAMP抑制hNPCs-G3神经前体细胞hTERT基因的转录,其调控主要作用在近端启动子区。结论神经前体细胞内源性hTERT基因的转录活性较低,bFGF可上调神经前体细胞内源性hTERT基因的表达,cAMP则可抑制hTERT基因的转录。更多还原

【Abstract】 Objective Using hTERT-immortalized human neural progenitor cell line,hNPCs-G3,it was studied on the transcription activity of endogenous human telomerase reverse transcriptase(hTERT) gene and the mechanisms of proliferation and differentiation in the human neural progenitor cells.Methods Transient co-transfection of hTERT promoter-luciferase constructs and pSV-β-Gal control vector into HeLa cells and hNPCs-G3 cells,and detection of the transcription activities of different hTERT promoter-luciferase constructs.After co-tansfection as above,hNPCs-G3 cells were induced by bFGF,and the transcription activities of different length of hTERT promoters responsive to proliferation were analyzed.After the co-tansfection as above,hNPCs-G3 cells were induced by cAMP,and the transcription activities of different length of hTERT promoters responsive to differentiation were analyzed.Results The transcription activity of endogenous hTERT gene was low in human neural progenitor cells,and activity of the proximal promoter was the highest.bFGF could up-regulate the activitiy of endogenous hTERT gene in human neural progenitor cells,which mainly depended on the stretch of-2 098bp to-1 099bp and-3 216bp to-2 098bp upstream of ATG.cAMP could down-regulate the transcription activity of endogenous hTERT gene in human neural progenitor cells,which inhibited the activity of proximal promoter.Conclusion The transcription activity of endogenous hTERT gene was low in human neural progenitor cells.bFGF could up-regulate the activitiy of endogenous hTERT gene in human neural progenitor cells and cAMP could down-regulate the transcription activity.更多还原