Mays P K, McAnulty R J, Campa J S, Laurent G J
Centre for Respiratory Research, University College London Medical School, Rayne Institute, U.K.
Int J Biochem Cell Biol. 1995 Sep;27(9):937-45. doi: 10.1016/1357-2725(95)00056-u.
The cultured fibroblast has been extensively used as a model system to study aging. However, few studies have examined the veracity of observations obtained in cultured fibroblasts aged in vitro to those made in animal tissues in vivo. This paper compares age-related alterations in collagen metabolism measured in cultured cells with previously reported results in the aging rat (Mays et al. (1991) Biochem. J. 276, 307-313). Age-related changes in collagen synthesis in rat skin fibroblasts in vitro over 30 population doublings were determined based on the production of hydroxy-[14C]proline. Degradation of newly synthesized collagen was based on the appearance of free hydroxy-[14C]proline in the culture system. Total protein synthesis rates were based on the incorporation of [14C]proline into proteins. In vitro rates of collagen synthesis decreased 5-fold over 30 population doublings (P < 0.05). Degradation of newly synthesized collagen increased from 33.0 +/- 0.8% (n = 4, SEM) to 45.2 +/- 1.1% (n = 4; P < 0.05) over the same period, with a maximum after 25 population doublings of 55.8 +/- 1.1% (n = 4). Total protein synthesis rates decreased by one-half over 30 population doublings (P < 0.05). The results indicated that collagen production decreased as cells aged in vitro and that this was due to both changes in synthesis and degradation. The results demonstrate that age-related alterations in collagen and total protein metabolism of skin fibroblasts in culture were similar to those reported previously for skin in vivo, suggesting that for studies of these processes, fibroblasts in culture provide an appropriate model.
培养的成纤维细胞已被广泛用作研究衰老的模型系统。然而，很少有研究检验在体外老化的培养成纤维细胞中获得的观察结果与在动物体内组织中所做观察结果的真实性。本文将培养细胞中测得的与年龄相关的胶原代谢变化与先前报道的衰老大鼠的结果进行了比较（Mays等人，(1991) Biochem. J. 276, 307 - 313）。基于羟化[14C]脯氨酸的产生，测定了大鼠皮肤成纤维细胞在体外超过30次群体倍增过程中与年龄相关的胶原合成变化。新合成胶原的降解基于培养系统中游离羟化[14C]脯氨酸的出现。总蛋白质合成率基于[14C]脯氨酸掺入蛋白质的情况。在30次群体倍增过程中，体外胶原合成率下降了5倍（P < 0.05）。在同一时期，新合成胶原的降解从33.0 +/- 0.8%（n = 4，标准误）增加到45.2 +/- 1.1%（n = 4；P < 0.05），在25次群体倍增后达到最大值55.8 +/- 1.1%（n = 4）。总蛋白质合成率在30次群体倍增过程中下降了一半（P < 0.05）。结果表明，随着细胞在体外老化，胶原产生减少，这是由于合成和降解的变化所致。结果表明，培养的皮肤成纤维细胞中与年龄相关的胶原和总蛋白质代谢变化与先前报道的体内皮肤变化相似，这表明对于这些过程的研究，培养的成纤维细胞提供了一个合适的模型。
