人卵黄囊间质干细胞的分离纯化及诱导成脂的实验研究

目的:分离纯化及体外定向诱导人卵黄囊间质干细胞(YS-MSC)分化为脂肪细胞。方法:显微分离人卵黄囊, 经酶消化得到卵黄囊细胞, 卵黄囊细胞经贴壁培养、传代纯化得到人YS-MSC, 流式细胞仪检测YS-MSC表面抗原表达, 钙钴法测定碱性磷酸酶(AKP)活性;地塞米松、消炎痛、胰岛素定向诱导YS-MSC分化为脂肪细胞。油红O检测中性脂肪。结果:人卵黄囊间质干细胞易于分离、纯化, 体外培养增殖潜能大。卵黄囊间质干细胞CD29、CD44、CD166及CD105表达阳性, CD34、CD45和CD86为阴性;AKP弱阳性。卵黄囊间质干细胞经成脂诱导转化为大小不等的园形或椭圆形细胞, 可见胞浆内有少量微小脂滴形成, 随时间延长, 胞浆中脂滴相互融合, 胞核被挤于细胞的一侧, 经油红O染色脂滴染橘红色, 符合脂肪细胞的生物学特征。结论:人卵黄囊间质干细胞与成体间质干细胞表型一致, 在体外可以分化为脂肪细胞。

Purification and adipogenic differentiation of human yolk sac mesenchymal stem cells

AIM: To purify human yolk sac mesenchymal ste m cells (hYS-MSC) and investigate its adipogenic differentiation potential. METHODS: hYS-MSC were separated from yolk sac and purified via passa ged culture. Flow cytometric analysis was used to identify the phenotype of hYS- MSC and the alkaline phosphatase(AKP) expression of hYS-MSC was also tested. Adi pogenic differentiatio n of hYS-MSCs was induced by 10 mg/L insulin,10 -5 mol/L indomethacin and 1 0 -6 mol/L dexamethasone. Oil Red O was used for fat staining. RESUL TS: hYS-MSCs were purified at passages 2 or 3. Flow cytometric analysis showed the phenotype of purified YS-MSCs was uniformly positive for CD29, CD44, CD105, and CD166, and negative for reactivity to antigens CD34, CD45, or CD86. h YS-MSCs were weakly but clearly positive in AKP. Adipogenic differentiation of Y S-MSCs was induced by 10 mg/L insulin, 10 -5 mol/L indomethacin and 10 -6 mol/L dexamethasone. Accumulation of lipid-rich vacuoles positive in oil red O staining within the cells were appeared and nuclears were pushed to one side of th e cells during the period of induction. CONCLUSION: The phenotyp e of hYS-MSC is coincident with adult human mesenchymal stem cells. hYS-MSC can be induced to differentiate into adipocytes in vitro .