压应力对表皮干细胞增殖与分化的影响  

Effect of mechanical pressure stress on proliferation and differentiation of epidermal stem cells in vitro and in vivo

作　　者：刘文忠[1] 王瑶[1] 王志强[1] 李建福[2] 

机构地区：[1]内蒙古医学院解剖学教研室,内蒙古呼和浩特010059 [2]第三军医大学西南医院整形外科,重庆400038

出　　处：《感染．炎症．修复》2009年第1期34-37,F0003,共5页Infection Inflammation Repair

基　　金：国家自然科学基金资助项目(30772265;30570708);国家重点基础研究发展计划(973)项目(2005CB522603)

摘　　要：目的:初步观察压应力对表皮干细胞增殖分化的影响。方法:以大鼠的皮肤扩张动物模型为在体观察对象;4、8、12kPa的压应力予体外培养的大鼠表皮干细胞进行间歇加压(每天3次,每次2h,共1周)为离体观察对象。利用免疫组化染色、免疫荧光双染、细胞克隆形成率等技术与方法检测β1整合素、角蛋白19(K19)、角蛋白14(K14)、角蛋白10(K10)、α6整合素、CD71的表达特征,以及压应力对表皮干细胞增殖分化的影响。结果:组织学观察显示,扩张皮肤的表皮层明显增厚;表皮层的β1整合素、K19、K14阳性细胞数量于扩张的第5天开始增多,至15d达峰值后下降,扩张完成后20d趋于正常;棘层和颗粒层不仅可见上述阳性细胞,且出现α6整合素bri/CD71dim细胞的表达。体外培养的表皮干细胞,8kPa、12kPa的压应力作用1周后,细胞克隆形成率分别为48.67%、49.36%,明显高于4kPa组(23.17%)与对照组(23.00%),8kPa、12kPa组可见K10阳性细胞表达。结论:表皮干细胞具有压应力敏感性,适当的压应力可诱导表皮干细胞增殖与分化。Objective： To investigate the proliferation and differentiation of epidermal stem cells （ESCs） in vitro and in vivo under the influence of mechanical pressure. Methods： Seventy-two expanders were implanted on both sides of the back in 36 SD rats （2/rat）, and the expanders were randomly divided into two groups： expansion group and control group. In the animals of expansion group conventional intermittent skin expansion was executed. The skin samples were harvested within the area overlying the expander on days 5, 10, 15, and 20 during expanding process, and on 10 and 20 days intervals after the final injection, respectively. Keratin 19（K19）, β1 integrin, α6 integrin and CDT1 were employed to determine ESCs with immunostaining and immunofluorescence staining. ESCs isolated from neonatal rats were exposed to a steady cycle pressure of 4, 8, and 12 kPa for 2 h, 3 times a day for 7 days using a custom-made air controlled mechanical compression apparatus. As controls, these cells underwent sham pressure with identical technique but no stress. One week later, the cells were analyzed for β1 integrin, K19, α6 integrin, CD71 and K10 by immunohistochemical, immunofluorescence staining and colony forming efficiency （CFE）. Results：Epidermal thickness was histologically increased under the influence of expansion compared with non-expanded skin. Immunostaining positive cells for β1 integrin, K19, K14 and double immunofluorescence labeling for a6 integrin^bri/ CD71^dim commenced to increase on 5 days post-expansion and peaked on day 15. Then, the number of these positive cells began to gradually degraded, especially on 20 days after expansion. There was an apparent decrease in positive cell number, which was close to that of non-expanded skin. Importantly, few cells positive for β1 integrin, K19 and α6 integrin^bri/ CD71^dim were found scattering within the stratum spinosum and stratum granulosum of the epidermis during expansion process. Both 8 kPa and 12 kPa of intermittent pressure enhanced colo

关 键 词：压应力 表皮干细胞 增殖 分化 

分 类 号：R392.11[医药卫生—免疫学] R329.2[医药卫生—基础医学]