人体脂肪基质细胞成肌潜能研究

目的　研究分离的人体脂肪基质细胞经过诱导培养后向骨骼肌细胞分化的潜能。方法　通过脂肪抽吸术获取健康成人脂肪,机械分割后用Ⅰ型胶原酶消化,得到脂肪基质细胞。将脂肪基质细胞在BGJb培养基中原代培养10 d,在DMEM/F12培养基中进行成肌诱导培养20 d,获得细胞爬片。细胞爬片经4%多聚甲醛固定后,用甲苯胺蓝、Mallory磷钨酸苏木素染色观察细胞形态;Myosin单克隆抗体免疫细胞化学染色观察肌球蛋白表达情况。结果　经过成肌诱导培养的细胞与常规培养的脂肪基质细胞在形态上有明显的差异,表现为细胞体积增大,单个核的细胞融合形成多核的肌管样结构,胞浆内细胞器发达,肌浆网扩张并形成肌原纤维骨骼肌特异性的Myosin表达阳性。未经诱导的脂肪基质细胞在相同时间点无此现象。结论　人类脂肪基质细胞中存在着成体干细胞,在成肌诱导培养条件下具有向骨骼肌细胞分化的潜能。

A Study on Myogenic Differentiation of Human Adipose Tissue-derived Stromal Cells

OBJECTIVE: To isolate human adipose tissue-derived stromal cells and study the potential of osteogenic differentiation after inductive culture. METHODS: Liposuction human adipose tissues were minced and digested with collagenase type I. The obtained stromal cells were plated in BGJb medium as primary culture for ten days. The second passage cells were harvested and plated in DMEM/F12 medium supplemented with 10% FBS, 5% horse serum and 50 micromol/L hydrocortisone for myogenic induction culture. The cell-anchored slips were removed and fixed in 4% formaldehydam polymerisatum. Toluidine blue, Mallory's phosphotungstic hematoxylin staining and monoclonal antibody to human skeletal muscle myosin heavy chain immunocytochemical methods were used to assay the differentiation of cells. RESULTS: It was observed that the size and shape of induced cells were much different from those of non-induced cells. Toluidine blue, Mallory's phosphotungstic hematoxylin staining demonstrated there were many basophilic striations within cytoplasm and multinucleated myotubes were formed. Immunocytochemical stain indicated that characterastic skeletal myosin heavy chain was positive in myogenic induced cells. CONCLUSION: It seems that human adipose tissue represents an abundant reservoir of adult stem cells that have multi-germline potential to differentiate into myoblasts. Adipose tissue derived stromal cells will be another alternative source for cell-based tissue engineering in skeletal muscle reconstruction.