压应力对体外培养的表皮干细胞增殖分化的影响

目的： 初步观察间歇压应力对表皮干细胞增殖分化的影响并探讨其可能的作用机制。 方法： Ⅳ型胶原分离培养表皮干细胞，并用免疫组织化学PowervisionTM二步法和细胞周期分析进行鉴定；采用不同压应力（4 kPa、6 kPa、8 kPa、10 kPa、12 kPa）细胞培养体系装置培养表皮干细胞和进行细胞加压，利用表皮干细胞特异表达角蛋白19及终末分化细胞表达角蛋白10的特点和免疫组织化学PowervisionTM二步法检测加压前后表皮干细胞和终末分化细胞的变化。 结果： 分离、培养的表皮干细胞K19免疫组化染色阳性，细胞周期分析有84.80%的细胞处于G1期；8 kPa以上的间歇压应力作用粘附于硅胶膜上的表皮干细胞1周后，其数量明显增多，免疫组化染色发现其中有角蛋白10阳性细胞。 结论： 8 kPa以上的间歇压应力能诱导表皮干细胞增殖分化，表皮干细胞对机械应力的响应机制可能是其主要的生物学基础。

Effect of compressive stress on proliferation and differentiation of human epidermal stem cells cultured in vitro

AIM: To investigate the mechanism of proliferation and differentiation of human epidermal stem cells cultured in vitro under the influence of compressive stress.METHODS: Epidermal stem cells were isolated by adhering to type IV collagen and were cultured with conditioned medium,then were detected by Powervision~(TM) two-step immunohistochemical method with keratin 19 and cell cycle analysis.The cultured epidermal stem cells transplanted on silica gel membranes,which were put in a new apparatus,was designed to offer cell culture and intermittent compressive stress(4 kPa,6 kPa,8 kPa,10 kPa,12 kPa) for 2 h,3 times a day simultaneously.A week later,cells on silica gel membranes were identified with keratin 19 and 10 by Powervision~(TM) two-step immunohistochemical method.RESULTS: The new apparatus offered cell culture and intermittent compressive stress simultaneously.The isolated and cultured epidermal stem cells were identified with keratin 19 positive and 84.80 percent of them were showed in G_1 period with cell cycle analysis.Cells on silica gel membranes had been subjected intermittent compressive stress above 8 kPa for a week.The number of the cells was increased,which was more than that in control group.However,some cells identified by immunohistochemical staining with keratin 10 positive were detected among the disposed epidermal stem cells.CONCLUSION: The intermittent compressive stress above 8 kPa induces and promotes epidermal stem cells to proliferate and differentiate,indicating that epidermal stem cells respond to mechanical stress,probably is one of their major biological features.