正常皮肤和瘢痕组织表达β1整和素与系列角蛋白特征的比较性研究

Expression of stem cell markers in scars is different in children and adults

目的:采用特殊染色法研究幼儿与成人大面积重度烧伤后瘢痕组织表皮细胞表达β1整和素和角蛋白19、14以及10的特征与规律,并在此基础上确定表皮干细胞及短暂扩充细胞分布、数量的差异以及这些改变与瘢痕愈合关系。方法:分别取幼儿及成人健康皮肤与大面积深度烧伤后瘢痕组织。采用免疫组化方法检测表皮干细胞、短暂扩充细胞特异表达β1整和素和角蛋白19(K19)以及分化表皮细胞表达的角蛋白14与10(K14、K10)。结果:瘢痕组织表皮基底层表达β1整和素与K19的阳性细胞数较健康皮肤明显减少,阳性强度降低。瘢痕组织表皮中表达K14的阳性细胞仅位于表皮底部2～3层,明显少于健康皮肤,而K10表达阳性细胞则较健康皮肤分布广泛。结论:实验结果提示,瘢痕组织表皮基底层具有增殖能力的表皮干细胞和短暂扩充细胞明显少于健康皮肤,且瘢痕组织表皮干细胞的分化过程与健康皮肤不同,处于有丝分裂后细胞阶段的细胞比例降低,而终末分化细胞的比例明显增高。提示瘢痕组织表皮的增殖能力下降,细胞的分化行为紊乱,这可能是瘢痕组织表皮结构与功能改变、愈合能力下降的原因之一。

Objective: To study the expression characteristics of epidermal stem cells, transit amplifying cells, post-mitotic cells and terminally-differentiated cells in normal skin and scar epidermis from children and adults, and to explore the mechanisms of abilities of self-renewal and wound healing in scar. Methods: β1 integrin and keratin 19 (K19) were used as the biochemical markers for stem cell and transit amplifying cell identification, and keratin 14 (K14) and keratin (K10) were used as the marker for post-mitotic cells and terminally-differentiated cells, respectively. Normal skin and scar were taken from children (4-10yrs) and adults (35-51yrs). Immunohistoehemistry was used to determine the expression of different stem cell markers. Results: It was shown that β1 integrin and K19 positive expression cells were less in scar than in normal skin. The proportion of K14 positive cells was decreased, and K10 expression cells were observed in all epidermal cells except basal layer in scar tissue. Conclusion: These results indicated that stem cells and transit amplifying cells in scar epidermis were less than those in normal skin, and proportions of post-mitotic cells and terminally-differentiated cells were abnormal, which might constitute the reason for the decreasing ability of self-renewal and wound healing in scar.