Dumont P, Burton M, Chen Q M, Gonos E S, Frippiat C, Mazarati J B, Eliaers F, Remacle J, Toussaint O
The University of Namur (FUNDP), Department of Biology, Laboratory of Cellular Biochemistry and Biology, Namur, Belgium.
Free Radic Biol Med. 2000 Feb 1;28(3):361-73. doi: 10.1016/s0891-5849(99)00249-x.
We tested the long-term effects of sublethal oxidative stresses on replicative senescence. WI-38 human diploid fibroblasts (HDFs) at early cumulative population doublings (CPDs) were exposed to five stresses with 30 microM tert-butylhydroperoxide (t-BHP). After at least 2 d of recovery, the cells developed biomarkers of replicative senescence: loss of replicative potential, increase in senescence-associated beta-galactosidase activity, overexpression of p21(Waf-1/SDI-1/Cip1), and inability to hyperphosphorylate pRb. The level of mRNAs overexpressed in senescent WI-38 or IMR-90 HDFs increased after five stresses with 30 microM t-BHP or a single stress under 450 microM H(2)O(2). These corresponding genes include fibronectin, osteonectin, alpha1(I)-procollagen, apolipoprotein J, SM22, SS9, and GTP-alpha binding protein. The common 4977 bp mitochondrial DNA deletion was detected in WI-38 HDFs at late CPDs and at early CPDs after t-BHP stresses. In conclusion, sublethal oxidative stresses lead HDFs to a state close to replicative senescence.
我们测试了亚致死性氧化应激对复制性衰老的长期影响。处于早期累积群体倍增（CPD）阶段的WI-38人二倍体成纤维细胞（HDF）用30微摩尔叔丁基过氧化氢（t-BHP）暴露于五种应激条件下。在至少2天的恢复后，细胞出现了复制性衰老的生物标志物：复制潜能丧失、衰老相关β-半乳糖苷酶活性增加、p21（Waf-1/SDI-1/Cip1）过表达以及无法使pRb过度磷酸化。在经30微摩尔t-BHP五次应激或450微摩尔H₂O₂单次应激后，衰老的WI-38或IMR-90 HDF中过表达的mRNA水平增加。这些相应的基因包括纤连蛋白、骨粘连蛋白、α1（I）-前胶原、载脂蛋白J、SM22、SS9和GTP-α结合蛋白。在晚期CPD阶段以及t-BHP应激后的早期CPD阶段的WI-38 HDF中检测到常见的4977碱基对线粒体DNA缺失。总之，亚致死性氧化应激导致HDF进入接近复制性衰老的状态。
