Lipid analysis of cell membranes in normal dermis, hypertrophic and keloidal scars

增生性瘢痕(HS)是伤口愈合异常的结果。HS形成的基本机制尚不清楚，但已发现与HS形成有关的许多因素：肥大细胞、转化生长因子-β和培养的成纤维细胞。与正常皮肤相比，HS中肥大细胞的数量增加了4倍。尽管HS会产生过量的胶原蛋白，但HS和正常皮肤的成纤维细胞具有相似的增殖率。HS来源的成纤维细胞的行为更像来自正常瘢痕的成纤维细胞，而不是来自瘢痕疙瘩的成纤维细胞，没有表现出对转化生长因子的夸大反应--我们专注于HS所涉及的脂肪酸，假设某些脂类影响HS的形成和维持。一些研究人员描述了脂质与瘢痕形成和伤口愈合之间的相互作用。我们检测了膜中含有的脂肪酸，并通过膜参与了每一反应；然后我们分析了去上皮化的正常真皮(ND)和HS中脂肪酸的百分比组成。体内HS样本取自6例手术切除患者，ND样本取自5例超量植皮患者。体外培养的HS和ND成纤维细胞也进行了分析。分析了所有样品中提取的脂肪酸的百分比组成。在体内，从整个组织和细胞膜的磷脂中，HS组的花生四烯酸(20：4)显著高于ND组。在体外，ND、HS和10%胎牛血清(FCS)之间的差异不显著。结果表明，HS的形成不一定涉及20：4-酸的简单过量，但ND和HS在20：4-酸的百分比组成上有很大的差异。花生四烯酸可能参与HS的形成和维持，而体外培养的成纤维细胞受FCS的影响较大。

Hypertrophic scars (HS) are the consequence of abnormal wound healing. The basic mechanism of HS formation is still unknown; however; a number of factors involved in HS formation have been revealed: the mast cells, TGF-beta, and cultured fibroblasts. Compared with normal skin, HS demonstrate four-fold increase in the numbers of mast cells. Although HS produce excess collagen, fibroblasts from HS and normal skin have similar proliferation rates. Fibroblasts derived from HS behave more like those from normal scars than those from keloids by not exhibiting an exaggerated response to TGF-□ We focused on fatty acids involved in HS on the hypothesis that some lipids influence HS formation and maintenance. Several investigators have described the interactions between lipids and scarring and wound healing. We examined fatty acids that are contained within, and participate in every reaction through membrane; then we analyzed the percentage composition of the fatty acids in de-epithelialized normal dermis (ND) and HS. In vivo HS samples were obtained from 6 patients undergoing surgical excision, and ND samples from 5 patients undergoing skin grafting surgery for excess. In vitro, cultured fibroblasts from HS and ND were also analyzed. The percentage composition of fatty acids extracted from all the samples was analyzed. In vivo, arachidonic acid (20:4) was significantly more abundant in HS than in ND, in the phospholipids from both whole tissue and cell membrane. In vitro, there were no significant difference among ND, HS, and 10% fetal calf serum (FCS). The results suggest that HS formation does not necessarily involve simple excess of 20:4-acid; however, there are considerable differences in percentage composition of 20:4-acid between ND and HS. Arachidonic acid probably participates in the formation and maintenance of HS, whereas in vitro cultured fibroblasts are affected largely by FCS.