5-氮杂胞苷通过PI3K/Akt/mTOR通路介导人脂肪间充质干细胞向心肌细胞定向分化的研究

5-Azacytidine induces differentiation of adult adipose-derived mesenchymal stem cells to cardiomyocyte-like cells through PI3K/Akt/mTOR signaling pathway

目的:研究磷脂酰肌醇3激酶(PI3K)及其下游分子丝氨酸/苏氨酸激酶(Akt)和雷帕霉素靶蛋白(mTOR)所组成的信号通路在5-氮杂胞苷(5-aza)诱导人脂肪间充质干细胞(ADMSCs)向心肌细胞定向分化中的作用,探讨其信号转导机制。方法:利用胶原酶法分离、培养ADMSCs,并用10μmol/L的5-aza诱导其向心肌细胞定向分化,采用Western blot的方法分析5-aza诱导前后Akt通路相关蛋白的表达情况。结果:5-aza诱导前ADMSCs内Akt通路相关蛋白的表达水平较低,诱导后增强。PI3K抑制剂Ly294002处理后,Western blot结果显示,细胞内PI3K的磷酸化受到抑制和TnT的表达水平显著降低,具有统计学意义。结论:5-aza能诱导ADMSCs向心肌细胞分化,PI3K/Akt/mTOR信号通路在5-aza诱导ADMSCs向心肌细胞分化中发挥重要的调控作用。

Objective：To investigate the regulating effects of PI3K/Akt signaling pathway on the differentiation of the adult adipose-derived mesenchymal stem cells（ADMSCs）induced with 5-Azacytidine（5-aza）toward cardiomyocytes and to determine the possible mechanisms in signal transduction on differentiation of ADMSCs toward cardiomyocytes. Methods：ADMSCs were isolated and cultured in vitro.The differentiation of ADMSCs into cardiomyocytes was induced with 10μmol/L of 5-aza.After induction with 5-aza,the morphological alterations to the cells were examined under a phase contrast microscope,and changes in the proteins related with Akt in ADMSCs were examined with Western blot. Results：Before induction with 5-aza,the p-Akt level in ADMSCs was low.After induction with 5-aza,the levels of proteins related with Akt in ADMSCs were increased.After treatment with the PI3 Kinhibitor Ly294002,p-Akt level of the cells and the expression of TnT were decreased significantly. Conclusion：5-aza may induce differentiation of ADMSCs into cardiomyocytes,and the PI3K/Akt/mTOR signaling pathway plays an important role in mediating the differentiation of ADMSCs induced with 5-aza into cardiomyocytes.