Gessin J C, Brown L J, Gordon J S, Berg R A
Department of Biochemistry, University of Medicine & Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854.
Exp Cell Res. 1993 Jun;206(2):283-90. doi: 10.1006/excr.1993.1148.
Ascorbic acid has been shown to stimulate collagen synthesis in monolayer cultures of human dermal fibroblasts. In the present studies, we examined whether the presence of a collagen matrix influences this response of dermal fibroblasts to ascorbic acid. Fibroblasts and collagen were mixed and allowed to gel and contract for 6 days to form a matrix prior to determining the concentration and time dependence for ascorbic acid to affect collagen synthesis by fibroblasts within the matrix. Collagen synthesis was stimulated at levels at or above 10 microM ascorbic acid and was maximal after 2 days of treatment. This concentration and time dependence is similar to that of cells grown in monolayer cultures. The effects of transforming growth factor-beta (TGF-beta) and fibroblast growth factor (FGF) were also examined in this model. TGF-beta increased and FGF inhibited collagen synthesis in the gels, as has been shown for cells in monolayer cultures. The effects of potential inhibitors of lipid peroxidation induced by ascorbic acid were also examined in these matrices and compared to previous results obtained in monolayer cultures. Propyl gallate, cobalt chloride, alpha,alpha-dipyridyl, and alpha-tocopherol inhibited the ascorbic acid-mediated stimulation of collagen synthesis while mannitol had no effect. Natural retinoids inhibited total protein synthesis without the specific effect on collagen synthesis that was seen in monolayer cultures. These results indicate that ascorbic acid stimulates collagen synthesis in fibroblasts grown in a collagen matrix in a manner similar to that found in monolayer cultures. In contracting collagen gels, however, the magnitude of the effect is less and retinoids do not specifically inhibit collagen synthesis.
已证明抗坏血酸可刺激人皮肤成纤维细胞单层培养物中的胶原蛋白合成。在本研究中，我们研究了胶原蛋白基质的存在是否会影响真皮成纤维细胞对抗坏血酸的这种反应。在确定抗坏血酸影响基质中成纤维细胞胶原蛋白合成的浓度和时间依赖性之前，将成纤维细胞和胶原蛋白混合，使其凝胶化并收缩6天以形成基质。当抗坏血酸浓度达到或高于10微摩尔时，可刺激胶原蛋白合成，且在处理2天后达到最大值。这种浓度和时间依赖性与单层培养的细胞相似。在该模型中还研究了转化生长因子-β（TGF-β）和成纤维细胞生长因子（FGF）的作用。如在单层培养细胞中所示，TGF-β增加了凝胶中的胶原蛋白合成，而FGF则抑制了这种合成。还研究了抗坏血酸诱导的脂质过氧化潜在抑制剂在这些基质中的作用，并与之前在单层培养中获得的结果进行了比较。没食子酸丙酯、氯化钴、α,α-联吡啶和α-生育酚抑制了抗坏血酸介导的胶原蛋白合成刺激，而甘露醇则无作用。天然类维生素A抑制总蛋白合成，但对单层培养中所见的胶原蛋白合成没有特异性影响。这些结果表明，抗坏血酸以类似于单层培养中发现的方式刺激在胶原蛋白基质中生长的成纤维细胞中的胶原蛋白合成。然而，在收缩的胶原蛋白凝胶中，这种作用的程度较小，并且类维生素A不会特异性抑制胶原蛋白合成。
