骨髓间充质干细胞体外分化为心肌样细胞过程中结构蛋白的发育

目的探讨体外经5-氮杂胞苷诱导后的骨髓间充质干细胞(MSCs)分化成心肌样细胞过程中肌联蛋白在心肌结构蛋白发育过程中的作用。方法构建针对Wistar大鼠TITINN2B区设计的重组质粒pSITITIN,将其分别转染入体外培养7d的新生大鼠心肌细胞和经5-aza诱导后2周的MSCs中,免疫荧光检测肌联蛋白、MHC、肌动蛋白、cTnT的表达。结果重组质粒pSITITIN转染入正常心肌细胞后,肌联蛋白的表达减弱(P<0.001);转染入经5-aza处理的MSCs后,肌联蛋白、cTnT的表达减弱,MHC、肌动蛋白的表达无明显变化。结论MSCs可以被5-aza诱导分化成心肌样细胞,但分化程度不高,尚不具备完整的收缩结构基础,肌联蛋白对心肌结构蛋白发育过程有重要的意义。

Research of structure protein development during mesenchymal stem cells induction into cardiac muscle cells in vitro

Objective To observe whether mesenchymal stem cells(MSCs) which have been induced by 5-azacytidine(5-aza) can differentiate into cardiac like cells. To find out the role of TITIN playing during the development of cardiomycytes among structure proteins. Methods To establish a recombinant plasmid vector involving a shRNA which matching the base pair of rat TITIN N2B region mRNA perfectly,transfect it into normal neonatal cardiomyocytes and MSCs which have been induced by 5-aza respectively and investigate the expression of TITIN Z band,MHC,ACTIN as well as cTnT by immunofluorescence. Results The expression of TITIN was weakened after recombinant plasmid has been transfected into neonatal cardiomyocytes.The same thing happened upon MSCs that have been induced by 5-aza. The expression of cTnT was weakened after TITIN been silenced by small interfering RNA (siRNA). But there was obvious change in MHC and ACTIN. Conclusion Our results demonstrate that MSCs can be induced into cardiomyocyte-like cells by 5-aza in vitro,although the degree of differentiation is still lower and can not form intact contractive structure. TITIN plays an important role in the development of structure proteins.