School of Chemical and Biological Engineering, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul 151-744, Republic of Korea.
Biotechnol Appl Biochem. 2010 Apr 7;55(4):191-7. doi: 10.1042/BA20090307.
Cardiomyocytes in the heart reside in mechanically dynamic environments, such as those subject to cyclic mechanical strain. TGF-beta1 (transforming growth factor-beta1) stimulates cardiomyogenic marker expression of BMMSCs (bone-marrow-derived mesenchymal stem cells). In the present study, we tested the hypothesis that cyclic mechanical strain promotes TGF-beta1-mediated cardiomyogenic marker expression in BMMSCs in vitro. The mRNA expression of cardiac-specific genes was more up-regulated in BMMSCs cultured with a TGF-beta1 supplement and subjected to cyclic strain for 1 week than in BMMSCs cultured statically with a TGF-beta1 supplement. Immunocytochemical analyses and flow cytometric analysis showed that the proportions of cardiac troponin-I-positive cells and cardiac MHC (myosin heavy chain)-positive cells and the proportions of cells expressing tropomyosin respectively were increased to a greater extent by TGF-beta1with cyclic strain than by TGF-beta1 alone. These results showed that cyclic strain promotes TGF-beta1mediated cardiomyogenic marker expression in BMMSCs in vitro.
心肌细胞位于机械动态环境中，例如那些受到循环机械应变的环境。TGF-β1（转化生长因子-β1）刺激 BMMSCs（骨髓间充质干细胞）的心肌生成标志物表达。在本研究中，我们检验了这样一个假设，即循环机械应变促进 BMMSCs 中 TGF-β1 介导的心肌生成标志物表达。在 TGF-β1 补充剂培养下并接受 1 周循环应变的 BMMSCs 中，心脏特异性基因的 mRNA 表达比 TGF-β1 单独培养的 BMMSCs 更高地上调。免疫细胞化学分析和流式细胞术分析表明，与 TGF-β1 单独处理相比，循环应变和 TGF-β1 联合处理可更大程度地增加心肌肌钙蛋白 I 阳性细胞、心肌 MHC（肌球蛋白重链）阳性细胞和表达原肌球蛋白的细胞的比例。这些结果表明，循环应变促进 BMMSCs 中 TGF-β1 介导的心肌生成标志物表达。
