Merker K, Sitte N, Grune T
Clinics of Physical Medicine and Rehabilitation, Humboldt University Berlin, Berlin, D-10098, Germany.
Arch Biochem Biophys. 2000 Mar 1;375(1):50-4. doi: 10.1006/abbi.1999.1657.
It is suggested that the aging process is dependent on the action of free radicals. One of the highlights of age-related changes of cellular metabolism is the accumulation of oxidized proteins. The present investigation was undertaken to reveal the proliferation-related changes in the protein oxidation and proteasome activity during and after an acute oxidative stress. It could be demonstrated that the activity of the cytosolic proteasomal system declines during proliferative senescence of human MRC-5 fibroblasts and is not able to remove oxidized proteins in old cells efficiently. Whereas in young cells removal of oxidized proteins was accompanied by an increase in the overall protein turnover, this increase in protein turnover could not be seen in old MRC-5 fibroblasts. Therefore, our studies demonstrate that old fibroblasts are much more vulnerable to the accumulation of oxidized proteins after oxidative stress and are not able to remove these oxidized proteins as efficiently as young fibroblasts.
有人认为衰老过程取决于自由基的作用。细胞代谢与年龄相关变化的一个显著特点是氧化蛋白质的积累。本研究旨在揭示急性氧化应激期间及之后蛋白质氧化和蛋白酶体活性与增殖相关的变化。可以证明，在人MRC - 5成纤维细胞增殖性衰老过程中，胞质蛋白酶体系统的活性下降，且无法有效清除衰老细胞中的氧化蛋白质。在年轻细胞中，氧化蛋白质的清除伴随着总体蛋白质周转率的增加，而在衰老的MRC - 5成纤维细胞中则看不到这种蛋白质周转率的增加。因此，我们的研究表明，衰老的成纤维细胞在氧化应激后更容易受到氧化蛋白质积累的影响，并且不能像年轻成纤维细胞那样有效地清除这些氧化蛋白质。
