胰岛素样生长因子-1对骨骼肌源性干细胞的促增殖效应

PROLIFERATIVE EFFECT OF INSULIN-LIKE GROWTH FACTOR-1 ON MUSCLE-DERIVED STEM CELLS

目的观察胰岛素样生长因子-1(IGF-1)对骨骼肌源性干细胞(MDSCs)生长的影响。方法采用连续预贴壁法从新生小鼠后肢肌分离培养MDSCs;用含2%胎牛血清的DMEM培养基促进其向骨骼肌细胞分化。免疫细胞化学SP法检测干细胞标志Sca-1和骨骼肌细胞标志肌节(α-sarcomeric)肌动蛋白的表达情况;采用四甲基偶氮唑盐(MTT)比色法检测IGF-1对MDSCs增殖的影响,并分析IGF-1效应与培养时间以及与IGF-1浓度之间的关系。结果从新生小鼠后肢肌成功分离培养MDSCs,90%以上的MDSCs呈Sca-1阳性;在分化培养中MDSCs能够产生α-sarcomeric肌动蛋白阳性的肌管;IGF-1对MDSCs促增殖作用随细胞培养时间的延长逐渐明显;随IGF-1浓度的增加而增加,并逐渐趋于饱和。结论IGF-1对体外培养的MDSCs有促进增殖的作用。

Objective To explore the effect of insulin-like growth factor-1 （IGF-1） on the growth of muscle-derived stem cells （MDSCs）. Methods MDSCs were isolated from the hindlimb muscle of new born mice through serial preplates. DMEM with 2% fetal bovine serum was used to induce MDSCs to differentiate into skeletal muscle lineage. The expression of stem cell marker Sca-1 or skeletal muscle cell marker α-sarcomeric actin was examined by immunocytochemistry SP method. MTT colorimetric microassay was conducted to determine the effect of IGF-1 on MDSCs proliferation. The relationship between functioning and culture time and the relationship between functioning and IGF-1 concentration were studied. Results MDSCs were successfully isolated from the hindlimb of neonatal mice. Over 90% of the MDSCs showed Sca-1 positive immunoreactivity. MDSCs could give rise to α-sarcomeric actin positive myotubes in differentiation cultures. The proliferative effect of IGF-1 on MDSCs increased gradu ally with prolonged culture time. The elevation of IGF-1 concentration also increased the proliferative effect until it came to a saturation point. Conclusion IGF-1 can promote the proliferation of in vitro cultured MDSCs.