Ide T, Tsuji Y, Ishibashi S, Mitsui Y, Toba M
Mech Ageing Dev. 1984 Apr-May;25(1-2):227-35. doi: 10.1016/0047-6374(84)90143-x.
A human diploid fibroblast strain, TIG -1, ceased to proliferate at about 60-62 population doubling level. The percentage of nuclei incorporating [3H]thymidine during 24-h culture in fresh medium containing 10% fetal bovine serum was less than 2% in the senescent cells used in this study. Infection of these cells with human cytomegalovirus (HCMV), strain AD-169, increased the percentage of [3H]thymidine-labeled cells by about ten-fold. Equilibrium density gradient centrifugation analysis of purified DNA from infected cells showed that cellular DNA synthesis was stimulated preceded by the viral DNA synthesis. Ultraviolet irradiation of HCMV reduced the ability to induce DNA synthesis. Equilibrium density gradient centrifugation analysis of DNA which was labeled with 5-bromodeoxyuridine indicated semiconservative replication rather than repair synthesis. These results suggested that in a considerable fraction of human senescent cells host DNA replication could be reinitiated by infection with HCMV, but not by the addition of fetal bovine serum.
一种人类二倍体成纤维细胞系TIG-1，在大约60-62个群体倍增水平时停止增殖。在含有10%胎牛血清的新鲜培养基中进行24小时培养期间，本研究中使用的衰老细胞中掺入[3H]胸腺嘧啶核苷的细胞核百分比不到2%。用人巨细胞病毒（HCMV）AD-169株感染这些细胞，使[3H]胸腺嘧啶核苷标记的细胞百分比增加了约10倍。对感染细胞纯化DNA的平衡密度梯度离心分析表明，细胞DNA合成在病毒DNA合成之后受到刺激。HCMV的紫外线照射降低了诱导DNA合成的能力。用5-溴脱氧尿苷标记的DNA的平衡密度梯度离心分析表明是半保留复制而非修复合成。这些结果表明，在相当一部分人类衰老细胞中，宿主DNA复制可通过感染HCMV重新启动，但不能通过添加胎牛血清重新启动。
