Yang J, Chang E, Cherry A M, Bangs C D, Oei Y, Bodnar A, Bronstein A, Chiu C P, Herron G S
Department of Dermatology, Stanford University School of Medicine, Stanford, California 94305-5486, USA.
J Biol Chem. 1999 Sep 10;274(37):26141-8. doi: 10.1074/jbc.274.37.26141.
Normal human endothelial cells, like other somatic cells in culture, divide a limited number of times before entering a nondividing state called replicative senescence. Expression of the catalytic component of human telomerase, human telomerase reverse transcriptase (hTERT), extends the life span of human fibroblasts and retinal pigment epithelial cells beyond senescence without causing neoplastic transformation (Bodnar, A. G., Ouellette, M., Frolkis, M., Holt, S. E., Chiu, C. P., Morin, G. B., Harley, C. B., Shay, J. W., Lichtsteiner, S., and Wright, W. E. (1998) Science 279, 349-352; Jiang, X., Jimenez, G., Chang, E., Frolkis, M., Kusler, B., Sage, M., Beeche, M., Bodnar, A., Wahl, G., Tlsty, T., and Chiu, C.-P. (1999) Nat. Genet. 21, 111-114). Here, we show that both human large vessel and microvascular endothelial cells also bypass replicative senescence after introduction of hTERT. For the first time, we report that hTERT expression in these life-extended vascular cells does not affect their differentiated and functional phenotype and that these cells maintain their angiogenic potential in vitro. Furthermore, hTERT(+) microvascular endothelial cells have normal karyotype, and hTERT(+) endothelial cell strains do not exhibit a transformed phenotype. Relative to parental cells at senescence, hTERT-expressing endothelial cells exhibit resistance to induction of apoptosis by a variety of different conditions. Such characteristics are highly desirable for designing vascular transplantation and gene therapy delivery systems in vivo.
正常人类内皮细胞与培养中的其他体细胞一样，在进入一种称为复制性衰老的非分裂状态之前只能分裂有限次数。人端粒酶催化成分人端粒酶逆转录酶（hTERT）的表达可将人成纤维细胞和视网膜色素上皮细胞的寿命延长至衰老之后，且不会导致肿瘤转化（博德纳尔，A.G.，乌埃莱特，M.，弗罗尔基斯，M.，霍尔特，S.E.，邱，C.P.，莫林，G.B.，哈雷，C.B.，谢伊，J.W.，利希施泰纳，S.，和赖特，W.E.（1998年）《科学》279卷，349 - 352页；蒋，X.，希门尼斯，G.，张，E.，弗罗尔基斯，M.，库斯勒，B.，塞奇，M.，比奇，M.，博德纳尔，A.，瓦尔，G.，特尔斯特，T.，和邱，C.-P.（1999年）《自然遗传学》21卷，111 - 114页）。在此，我们表明，在导入hTERT后，人类大血管和微血管内皮细胞也能绕过复制性衰老。我们首次报道，在这些寿命延长的血管细胞中hTERT的表达不会影响它们的分化和功能表型，并且这些细胞在体外保持其血管生成潜力。此外，hTERT(+)微血管内皮细胞具有正常核型，hTERT(+)内皮细胞系不表现出转化表型。相对于衰老的亲本细胞，表达hTERT的内皮细胞对多种不同条件诱导的凋亡具有抗性。这些特性对于设计体内血管移植和基因治疗递送系统非常理想。
