点阵CO_2激光作用皮肤光老化模型后表皮干细胞的分布特征

Distribution characteristics of epidermal stem cells after treatment with fractional CO_2 laser in a model of skin photoaging

背景:临床应用点阵CO2激光治疗面部光老化已取得显著疗效,但点阵CO2激光作用于皮肤光老化模型创面修复过程中表皮干细胞的变化规律尚无研究。目的:观察点阵CO2激光作用小鼠皮肤光老化模型后创面愈合过程中表皮干细胞数量及其在表皮中的分布变化规律。方法:将10只昆明小鼠以UVB紫外线照射,制备成皮肤光老化模型,行点阵CO2激光(DeepFX)干预,观察激光创面愈合情况,并且于干预前、干预后第1,3,7,15天取材,行免疫组织化学染色观察角蛋白19和基因物质P63阳性表达。结果与结论:干预后第15天,点阵CO2激光创面基本愈合。激光干预后第3天角蛋白19和基因物质P63阳性细胞率高于干预前及干预第1天,并出现阳性细胞分布范围扩大。第7天阳性细胞率明显高于第1,3天,为最高值,排列结构紊乱,分布到表皮各层。第15天阳性细胞率下降,仅集中于表皮的基底层和毛囊隆突,阳性表达与干预前及干预后第1天无明显差别。结果可见表皮干细胞参与了点阵CO2激光干预小鼠光老化皮肤的修复过程,可能在该过程中发挥重要作用。

BACKGROUND： There has been some progress in clinical application of fractional CO2 laser for treatment of facial photoaging. However, little is known about the change law of epidermal stem cells during wound healing process after treatment with fractional CO2 laser in a model of skin photoaging. OBJECTIVE： To investigate the quantity and distribution of epidermal stem cells during wound healing process after treatment with fractional CO2 laser in a mouse model of skin photoaging. METHODS： Ten Kunming mouse models of skin photoaging developed by exposure to ultraviolet radiation were treated with fractional CO2 laser （Deep FX）. Wound healing was monitored and samples were harvested for determination of keratin 19 ad P63expression by immunohistochemical staining before and 13, 7 and 15 days after fractional CO2 laser treatment. RESULTS AND CONCLUSION： The wounds almost healed at 15 days after treatment. Compared to before and day 1 treatment, Keratin 19 and P63 expression on day 3 were significantly increased, and keratin 19- and P63-positive cells were distributed in larger areas. Compared to days 1 and 3 of treatment, keratin 19- and P63-positive cells were significantly higher in quality and peaked on day 7 of treatment, and they were disorderly arranged in each epidermal layer. On day 15 of treatment, keratin 19- and P63-positive cells decreased in number and only accumulated in epidermal basal lamina and hair follicle eminence, and there was no significant difference in keratin 19- and P63-positive expression as compared with before and day 1 of treatment. These findings suggest that epidermal stem cells participate in the repair progress of skin photoaging in mice receiving fractional CO2 laser treatment and may play an important role in this process.