烧伤后瘢痕组织中成纤维细胞ET-1表达及血管新生和胶原分布研究

目的 研究烧伤后不同时期瘢痕组织中成纤维细胞内皮素1(ET-1)表达以及新生血管形成和胶原纤维分布情况.方法 收集烧伤创面愈合后不同时期瘢痕组织标本(发生早期、增生期、消退期、成熟期各8例)和正常皮肤组织标本(正常对照,n=8)作为研究对象.体外分离培养成纤维细胞,RT-PCR半定量检测成纤维细胞中ET-1 mRNA的表达情况;新生血管标志物CD34免疫组织化学染色检测瘢痕组织内新生血管形成(CD34阳性细胞面积百分率);Masson三色染色法观察瘢痕组织胶原纤维分布.结果 瘢痕组织的发生早期,成纤维细胞ET-1 mRNA的表达水平逐渐升高,并于增生期达到高峰,消退期逐步降低,成熟期下降至最低水平.发生早期、增生期、消退期、成熟期瘢痕组织及正常对照组织中CD34阳性细胞面积百分比分别为(1.961±0.159)%、(3.432±0.237)%、(0.412±0.026)%、(0.354±0.025)%和(0.1917±0.018)%,不同时期瘢痕组织间及其与正常对照比较差异均有统计学意义(P＜0.05).Masson三色染色观察发现,增生期瘢痕组织胶原纤维显著增加,排列致密.结论 烧伤后瘢痕发生和演变过程中,成纤维细胞ET-1表达水平呈现发生早期逐步升高、增生期达到高峰、消退期下降的变化,与不同时期瘢痕组织中新生血管形成及胶原纤维分布变化趋势一致.

Expression of ET-1 in fibroblasts, angiogenesis and collagen distributions in scars after burn injury

Objective To investigate the expression of endothelin-1 (ET-1), angiogenesis and collagen fiber distributions in scars of different stages after burn. Methods Scar samples of different stages after wound healing of burn (early stage, proliferative stage, regressive stage and mature stage, n=8 for each stage) and normal skin tissue samples (normal controls, n=8) were collected. Fibroblasts were isolated and cultured in vitro, and semi-quantitative RT-PCR was employed to detect the expression of ET-1 mRNA in fibroblasts. Angiogenesis in scars was detected by immunohistochemical staining with angiogenesis marker CD34 (percentage of area with CD34 positive cells), and collagen fiber distributions in scars were observed by Masson staining. Results The expression of ET-1 mRNA in fibroblasts increased gradually in the scars of early stage, reached the peak in the proliferative stage, gradually decreased in the regressive stage and recovered to the level of normal controls in the mature stage. The percentages of area with CD34 positive cells of scars of early stage, proliferative stage, regressive stage, mature stage and normal controls were (1.961±0.159)%, (3.432±0.237)%, (0.412±0.026)%, (0.354±0.025)% and (0.1917±0.018)%, respectively, and there were significant differences among scars of different stages and normal controls (P<0.05). It was revealed by Masson staining that the collagen fibers significantly increased in number and densely lined in the proliferative stage of scars. Conclusion In the development and progression of scars after burn, the expression of ET-1 in fibroblasts gradually increases in the early stage, reaches the peak in the proliferative stage, and decreases in the regressive stage, which is well correlated with the changes of angiogenesis and collagen fiber distributions in scars of different stages.