Chung J H, Youn S H, Kwon O S, Cho K H, Youn J I, Eun H C
Department of Dermatology, Seoul National University College of Medicine, South Korea.
J Dermatol Sci. 1997 Sep;15(3):188-200. doi: 10.1016/s0923-1811(97)00607-5.
Decreased collagen synthesis and loss of responsiveness to growth factors are well known phenomena in in vivo or in vitro aged cells. Ascorbic acid and some cytokines such as transforming growth factor-beta and interferon-gamma are important regulators of collagen synthesis. To investigate the responsiveness of fibroblasts with regard to the photoaging and aging process, we examined the effect of ascorbic acid, TGF-beta, and IFN-gamma on collagen synthesis in dermal fibroblasts from three newborn foreskins (1 day old) and in both exposed and unexposed skin fibroblasts from 4 old individuals (60-76 years old) cultured in monolayer and in collagen gel. We demonstrated that basal levels of collagen synthesis decreased with increasing age. Photoaged fibroblasts in collagen gel showed greater basal collagen synthesis than aged fibroblasts in the same individuals, but similar basal collagen synthesis in monolayer cultures. Even though basal levels of collagen synthesis in collagen gel are downregulated in a photoaging- and aging-dependent manner, collagen synthesis by ascorbic acid in collagen gel, and by TGF-beta and IFN-gamma in both monolayer culture and collagen gel were regulated in a photoaging- and aging-independent manner. In monolayer culture, however, the responsiveness to ascorbic acid in newborn fibroblasts was greater than in photoaged and aged fibroblasts. Our results suggest that there are differences in collagen synthesis between photoaged and aged cells, depending on culture conditions. Responsiveness to ascorbic acid, TGF-beta and IFN-gamma related to collagen synthesis in photoaged and aged fibroblasts in collagen gel appears to be the same as in newborn fibroblasts, even though basal levels of collagen synthesis are downregulated in a photoaging- or aging-dependent manner.
胶原蛋白合成减少以及对生长因子反应性丧失是体内或体外老化细胞中众所周知的现象。抗坏血酸和一些细胞因子，如转化生长因子-β和干扰素-γ，是胶原蛋白合成的重要调节因子。为了研究成纤维细胞对光老化和自然老化过程的反应性，我们检测了抗坏血酸、转化生长因子-β和干扰素-γ对来自三个新生儿包皮（1日龄）的真皮成纤维细胞以及来自4名老年个体（60 - 76岁）的暴露和未暴露皮肤成纤维细胞在单层培养和胶原凝胶培养中胶原蛋白合成的影响。我们证明胶原蛋白合成的基础水平随年龄增长而降低。胶原凝胶中的光老化成纤维细胞比同个体的老化成纤维细胞显示出更高的基础胶原蛋白合成，但在单层培养中基础胶原蛋白合成相似。尽管胶原凝胶中胶原蛋白合成的基础水平以光老化和自然老化依赖的方式下调，但胶原凝胶中抗坏血酸以及单层培养和胶原凝胶中转化生长因子-β和干扰素-γ所介导的胶原蛋白合成是以光老化和自然老化不依赖的方式调节的。然而，在单层培养中，新生成纤维细胞对抗坏血酸的反应性大于光老化和成纤维细胞。我们的结果表明，根据培养条件，光老化细胞和老化细胞在胶原蛋白合成方面存在差异。尽管胶原蛋白合成的基础水平以光老化或自然老化依赖的方式下调，但胶原凝胶中光老化和老化成纤维细胞中与胶原蛋白合成相关的对抗坏血酸、转化生长因子-β和干扰素-γ的反应性似乎与新生成纤维细胞相同。
