hTERT基因转染对人胚胎成纤维细胞端粒长度、端粒酶活性及其亚单位的影响

EFFECTS OF EXOGENOUS hTERT TRANSFECTION ON TELOMERIC RESTRICTION FRAGMENT,TELOMERASE ACTIVITY AND ITS SUBUNITS EXPRESSION OF HUMAN EMBROYNIC FIBROBLASTS

为了探讨外源性人端粒酶蛋白催化亚单位 (hTERT)基因转染对人胚胎成纤维细胞 (hEFs)端粒长度、端粒酶活性及其亚单位的影响 ,采用基因重组技术构建hTERT全长cDNA正义荧光真核表达载体 ,并采用脂质体法将正义重组质粒pIRES2 EGFP hTERT及空载质粒pIRES2 EGFP分别转染原代培养hEFs,检测转染细胞端粒长度、端粒酶活性及端粒酶亚单位的变化。结果显示 ,外源性hTERT基因转染细胞 (hEF hTERT)端粒酶活性较未转染细胞 (hEFs)及空载体转染细胞 (hEF EGFP)显著增加 (P <0 0 1) ,hEF hTERT、hEFs及hEF EGFP端粒长度分别为 6 0kb、5 3kb及 5 4kb ,端粒酶亚单位中除hTERT在mRNA和蛋白水平表达均增加外 ,hTR和TP1mRNA无明显变化。以上结果提示 ,外源性hTERT基因转染能使原代培养的hEFs端粒酶活化 ,端粒长度不再继续缩短 ,hTERT在mR

In order to explore the effects of exogenous human telomerase reverse transcriptase (hTERT/hTRT/hEST2) on telomeric restriction fragment (TRF), telomerase activity and its subunits expression in human embryonic fibroblasts (hEFs), hTERT sense eukaryotic expression vector pIRES2 EGFP hTERT was constructed with DNA recombinant technique and then transfected into primary hEFs by Lipofectin method. TRF length, telomerase activity and changes in telomerase subunits expression were examined and evaluated in transfected and untransfected cells. The results showed that telomerase activity in pIRES2 EGFP hTERT transfected cells (hEF EGFP) was significantly higher than that in untransfected hEFs and vacant vector transfected cells (hEF EGFP) ( P <0 01). TRF length in hEF hTERT, hEFs and hEF EGFP were 6 0kb, 5 3kb, and 5 4kb respectively. Among the three subunits of telomerase, only levels of mRNA and protein of hTERT expression were increased, whereas hTR and TP1 mRNAs remained unchanged. The results suggested that telomerase of hEFs could be activated and telomeric length could be lengthened by exogenous hTERT transfection.