骨髓间充质干细胞体外培养及肝向分化方案的优化

摘要

目的 优化一套简便、可靠、稳定的大鼠骨髓间充质干细胞分离、培养、鉴定及肝向分化的方案.方法 采用全骨髓差速贴壁法分离提取大鼠骨髓间充质干细胞,通过优化的1.5 h差速贴壁结合12 h首次全量换液方法,及体外改良培养方案实现细胞高效纯化扩增.流式细胞术表面标志物检测结合成脂、成骨、成软骨诱导分化鉴定细胞群.采用添加bFGF、HGF、EGF等多种生长因子的三步诱导法促使骨髓间充质干细胞向肝系分化,并进行形态学、免疫学、基因水平评估.结果 分离纯化的细胞群阳性表达CD29、CD44、CD90,阴性表达CD34、CD45,经成脂、成骨、成软骨诱导液作用后,油红O、茜素红、甲苯胺蓝染色均呈阳性.经三步法肝向诱导处理后,细胞群呈肝样细胞形态改变,表达肝脏特异性标志物ALB、AFP,肝系相关基因表达水平呈时间依赖性逐渐上升.结论 优化后的方案能够简便、可靠、稳定地获得高纯度的大鼠骨髓间充质干细胞,并能在特定微环境作用下实现肝向分化.%Objective To optimize the protocols for isolation, in vitro culture, identification and induction of hepatic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). Methods Rat BMSCs were separated and purified by differential adherent culture for 1.5 h with the first medium change at 12 h. The surface markers of BMSCs were detected by flow cytometry. The cells were induced to differentiate into adipogenic, osteogenic, and chondrogenesis lineages. A 3-step protocol including sequential addition of growth factors, cytokines and hormones was used to induce the BMSCs to differentiate into hepatocyte-like cells. Results The cells isolated using this protocol were positive for CD29, CD44, and CD90 and negative for CD29 and CD45. The adipogenic, osteogenic, and chondrogenic differentiation of the BMSCs were verified by Oil red, Alizarin red, and toluidine blue staining. The BMSCs induced with the 3-step protocol differentiated into hepatic-like cells that expressed hepatocyte-specific proteins (ALB and AFP) and genes. Conclusion The optimized protocol allows simple and efficient isolation of highly purified populations of BMSCs, which can be induced into hepatic lineages in specific microenvironment.