小鼠骨髓间充质干细胞体外诱导向平滑肌样细胞分化过程中myocardin的表达

The Expression of Myocardin in Differentiation of Mouse Bone Mesenchymal Stem Cell into Smooth Muscle-Like Cells in Vitro

目地探讨血小板源性生长因子BB联合高浓度胎牛血清体外诱导骨髓间充质干细胞定向分化为平滑肌细胞的可行性及myocardin在此过程中的表达变化。方法采用全骨髓贴壁法分离骨髓间充质干细胞,血小板源性生长因子BB(50μg/L)联合高浓度胎牛血清诱导骨髓间充质干细胞,分别于诱导前,及诱导4d和8d后用免疫细胞化学法检测细胞平滑肌肌动蛋白、平滑肌肌球蛋白重链和myocardin的表达。结果免疫组织化学显示,诱导前及诱导4d和8d时,平滑肌肌动蛋白、平滑肌肌球蛋白重链和myocardin三种蛋白的表达逐渐增强,平均灰度值逐渐降低,不同时间点之间比较差异有显著性(P<0.05)。结论血小板源性生长因子BB联合高浓度胎牛血清可有效诱导骨髓间充质干细胞向平滑肌样细胞分化。Myocardin在此分化过程中可能起了重要作用。

Aim To investigate the feasibility of differentiation of bone marrowmesenchymal stem cell （BMSC） into smooth muscle cell （SMC） in vitro under platelet-derived growth factor -BB （50 μg/L） and high concentrations of fetal bovine serum（FBS） （20%）, and the positive effect of myocardin on BMSC differentiating into SMC. Methods Mouse BMSCs were isolated and purifed from bone marrow, then 50 μg/L PDGF-BB and FBS（20% ）were added to the BMSCs. And the cells were cultuted for 4 and 8 days respectively. Immunohistochemistry assay and image analysis were used to value the exptession extent of α-smooth muscle actin（α-SMA）, smooth muscle myosin heavy chain（SM-MHC）and myocardin. Results Intensities of the three protein immunostaining significantlv increased after 4 antl 8 days. And Test of One-way ANOVA showed that there was statistically significance in different times （ P 〈 0. 05 ）. Conclusions BMSC could be induced to differetiate into smooth musclelike （SM-like） cells through adding PDGF-BB （50 μg/L） and FBS （20%） with BMSC in vitro. Myocardin may play an important role in this process.