骨髓间充质干细胞分化为皮肤附属器细胞的初步实验研究

目的探讨骨髓间充质干细胞(marrowmesenchymalstemcells,MSCs)分化为创面皮肤附属器细胞的可能性,及其参与创面修复的可能机制。方法无菌条件下取Wistar大鼠股骨骨髓细胞,密度梯度离心分离、纯化MSCs,体外培养扩增后,用BrdU标记细胞。另于同种雄性Wistar大鼠背部正中,制备1cm×1cm全厚皮肤缺损创面模型,将BrdU标记的1×106/mlMSCs从阴茎静脉输注,术后第3天与第7天切取创面组织,行BrdU免疫组织化学单染色,以及BrdU和广谱角蛋白免疫组织化学双染色。结果BrdU阳性细胞出现在创面皮下组织、皮脂腺、毛囊和骨髓腔中。免疫组织化学双染色结果显示,皮脂腺和毛囊有BrdU阳性细胞,同时表达广谱角蛋白。结论创面愈合过程中,MSCs归巢并参与创面修复;在实验性全身皮肤缺损创面微环境下,MSCs可分化为皮肤附属器细胞。

PRIMARY EXPERIMENTAL STUDIES ON DIFFERENTIATION OF MARROW MESENCHYMAL STEM CELLS INTO SKIN APPENDAGE CELLS IN VIVO

OBJECTIVE: To investigate the feasibility of differentiation of the marrow mesenchymal stem cells (MSCs) into the cells of the skin appendages and the mechanism of their involvement in the wound healing. METHODS: The bone marrow was collected from Wistar rats by the flushing of the femurs, MSCs were isolated and purified by the density gradient centrifugation. Then, the MSCs were amplified and labelled with 5-bromo-2'-deoxyuridine (BrdU). The full-thickness skin wounds with an area of 1 cm x 1 cm were made on the midback of the homogeneous male Wistar rats. At the same time, 1 x 10(6)/ml BrdU-labelled MSCs were infused from the penile vein. The specimens were harvested from the wound tissues on the 3rd day and the 7th day after operation and were immunohistochemically stained by either BrdU or BrdU and pan-keratin. RESULTS: The BrdU positive cells appeared in the hypodermia, the sebaceous glands, and the hair follicles of the wounds, as well as the medullary canal of the femurs. The double-staining showed the BrdU positive cells in the sebaceous glands and the hair follicles of the wounds expressed pan-keratin simultaneously. CONCLUSION: During the course of the wound healing, MSCs are involved in the wound repair and can differentiate into the cells of the skin appendages under the microenvironment of the wound.