Rezaee Nasim, Tafazzoli-Shadpour Mohammad, Haghighipour Nooshin
Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran.
Cardiovascular Engineering Lab, Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran.
Prog Biomater. 2018 Dec;7(4):279-288. doi: 10.1007/s40204-018-0102-5. Epub 2018 Oct 26.
Differentiation of stem cells and functionality of target cells are regulated by microenvironmental stimuli to which the cells are exposed. Chemical agents such as growth factors and physical parameters including mechanical loadings are among major stimuli. In this study, equiaxial cyclic strain with two amplitudes was applied on rat adipose-derived mesenchymal stem cells (rAMSCs) with or without 5-azacytidine. The mRNA expression of cardiac-related genes was investigated through RT-PCR (polymerase chain reaction) method. Moreover, morphological features and the actin structure of the cells were studied. Results were indications of significant increase in mRNA expression among four target genes, which marked the increase in two principal cardiac markers of GATA4 and α-cardiac actin, and lesser increase in two other genes (NKX2-5, βMHC) in all experimental groups treated chemically and/or mechanically. Such effect was maximal when both treatments were applied describing the synergistic effect of combined stimuli. All treatments caused significant increase in cell area and cell shape index. The well spreading of cells was accompanied by enhanced actin structure, especially among samples subjected to mechanical stimulus. Both effects were among required features for functional muscle cells such as cardiac cells. It was concluded that the cyclic equiaxial strain enhanced cardiomyogenic induction among rat adipose-derived mesenchymal stem cells and such effect was strengthened when it was accompanied by application of chemical factor. Results can be considered among strategies for cardiomyogenic differentiation and can be employed in cardiac tissue engineering for production of functional cardiomyocytes to repair of damaged myocardium.
干细胞的分化和靶细胞的功能受细胞所接触的微环境刺激调控。主要刺激因素包括生长因子等化学试剂以及机械负荷等物理参数。在本研究中，对有或无5-氮杂胞苷的大鼠脂肪来源间充质干细胞（rAMSCs）施加两种幅度的等轴循环应变。通过逆转录聚合酶链反应（RT-PCR）方法研究心脏相关基因的mRNA表达。此外，还研究了细胞的形态特征和肌动蛋白结构。结果表明，在所有化学和/或机械处理的实验组中，四个靶基因的mRNA表达显著增加，这标志着两个主要心脏标志物GATA4和α-心肌肌动蛋白的增加，另外两个基因（NKX2-5、βMHC）的增加较少。当同时应用两种处理时，这种效果最大，表明联合刺激具有协同作用。所有处理均导致细胞面积和细胞形状指数显著增加。细胞的良好铺展伴随着肌动蛋白结构的增强，尤其是在受到机械刺激的样本中。这两种效应都是功能性肌肉细胞（如心肌细胞）所需的特征。得出的结论是，等轴循环应变增强了大鼠脂肪来源间充质干细胞的心肌生成诱导作用，当伴有化学因子应用时，这种作用会增强。这些结果可被视为心肌生成分化策略之一，并可用于心脏组织工程中生产功能性心肌细胞以修复受损心肌。
