Institute of Catholic Integrative Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Incheon 403-720, Republic of Korea.
Biochem Biophys Res Commun. 2012 Aug 10;424(4):740-6. doi: 10.1016/j.bbrc.2012.07.022. Epub 2012 Jul 15.
To achieve effective regeneration of injured myocardium, it is important to find physiological way of improving the cardiogenic differentiation of stem cells. Previous studies demonstrated that cardiomyocytes from bone marrow-derived mesenchymal stem cells (BMSCs) activated with phorbolmyristate acetate (PMA), a protein kinase C (PKC) activator, restore electromechanical function in infarcted rat hearts. In this study, we investigated the effect of PMA on cardiogenic differentiation of adipose-derived MSCs (ASCs) for clinical applications. To confirm the effect of PMA, ASCs treated with 1μM PMA were grown for nine days. The expression of cardiac-specific markers (cardiac troponin T, myosin light chain, myosin heavy chain) in PMA-treated MSCs was demonstrated by immunocytochemistry. Alhough few α(1A) receptors exist in ASCs, α(1)-adrenergic receptor subtypes were preferentially expressed in PMA-treated ASCs. Moreover, expression of the β-adrenergic and muscarinic receptors increased in PMA-treated ASCs compared to normal cells. The mRNA levels of Ca(2+)-related factors (SERCA 2a; sarcoplasmic reticulum Ca(2+)-ATPase, LTCC; L-type Ca(2+) channel) in treated ASCs were similar to the levels in cardiomyocytes. Following the transplantation of chemically activated cardiogenic ASCs into infarcted myocardium, histological analysis showed that infarct size, interstitial fibrosis, and apoptotic index were markedly decreased and cardiac function was restored. In conclusion, PMA might induce the cardiogenic differentiation of human ASCs as well as BMSCs. This result suggests successful use of human ASCs in cardiac regeneration therapy.
为了实现受损心肌的有效再生，找到能够提高干细胞心脏生成分化能力的生理方法非常重要。先前的研究表明，用佛波醇肉豆蔻酸酯（PMA）激活的骨髓间充质干细胞（BMSCs）产生的心肌细胞可恢复梗死大鼠心脏的机电功能，PMA 是蛋白激酶 C（PKC）激活剂。在这项研究中，我们研究了 PMA 对脂肪来源的间充质干细胞（ASCs）的心脏生成分化的影响，以便将其应用于临床。为了证实 PMA 的作用，用 1μM PMA 处理 ASC 并培养 9 天。通过免疫细胞化学显示 PMA 处理的 MSC 中心脏特异性标志物（心肌肌钙蛋白 T、肌球蛋白轻链、肌球蛋白重链）的表达。尽管 ASCs 中存在少量的α(1A)受体，但 PMA 处理的 ASCs 中优先表达α(1)-肾上腺素能受体亚型。此外，与正常细胞相比，PMA 处理的 ASCs 中β-肾上腺素能和毒蕈碱能受体的表达增加。处理的 ASCs 中与 Ca(2+)相关的因子（肌浆网 Ca(2+) -ATP 酶，SERCA 2a；肌浆网 Ca(2+) -ATP 酶，LTCC；L 型 Ca(2+)通道）的 mRNA 水平与心肌细胞相似。化学激活的心脏生成性 ASCs 移植到梗死心肌后，组织学分析显示梗死面积、间质纤维化和细胞凋亡指数明显减少，心脏功能得到恢复。总之，PMA 可能诱导人 ASCs 及 BMSCs 的心脏生成分化。这一结果表明，人类 ASC 可成功应用于心脏再生治疗。
