Universidade Federal de Viçosa, Viçosa, MG, Brasil.
Arq Bras Cardiol. 2013 Jan;100(1):82-9. doi: 10.1590/s0066-782x2012005000114. Epub 2012 Dec 11.
Cardiomyocytes have small potential for renovation and proliferation in vivo. Consequently, the heart muscle has limited capacity of self-renewal. Mesenchymal stem cells (MSC) therapy, as well as MSC differentiated into cardiomyocytes, has been used in the attempt to minimize the effects of ischemic-hypoxic lesions and those affecting the electrical conduction system of the heart.
The present study compared three distinct protocols for induced differentiation of MSC into cardiomyocytes aimed at finding a viable method for producing a large number of functional cells expressing cardiomyogenic phenotype.
Mesenchymal stem cells were obtained from the adipose tissue of young transgenic Lewis rats expressing green fluorescent protein (GFP), and submitted to three distinct differentiation-inducing media: 1) Planat-Bérnard, 2) 5-azacytidine, and 3) Planat-Bérnard + 5-azacytidine; further, these cells were identified based on the expression of cardiac cell markers.
All three protocols detected the expression of sarcomeric-alpha-actinin protein in the exoskeleton of cells, expression of connexin-43 in the nuclear and cytoplasmic membrane, and formation of gap junctions, which are necessary for electrical impulse propagation in the myocardium. However, no spontaneous cell contraction was observed with any of the tested protocols.
Induction with 5-azacytidine provided an effective cadiomyogenic cellular differentiation similar to that obtained with Planat-Bénard media. Therefore, 5-azacytidine was the method of choice for being the simplest, fastest and lowest-cost protocol for cell differentiation.
心肌细胞在体内的更新和增殖潜力较小。因此，心肌的自我更新能力有限。间充质干细胞（MSC）治疗以及分化为心肌细胞的 MSC 已被用于尝试最小化缺血缺氧损伤以及影响心脏电传导系统的影响。
本研究比较了三种不同的 MSC 向心肌细胞诱导分化方案，旨在寻找一种可行的方法来产生大量表达心肌表型的功能性细胞。
从小鼠的脂肪组织中分离出表达绿色荧光蛋白（GFP）的间充质干细胞，并将其置于三种不同的诱导分化培养基中：1）Planat-Bérnard 培养基，2）5-氮杂胞苷培养基，3）Planat-Bérnard+5-氮杂胞苷培养基；进一步，根据心肌细胞标志物的表达来鉴定这些细胞。
所有三种方案都检测到细胞外骨骼中肌节-α-肌动蛋白蛋白的表达、核和细胞质膜中连接蛋白 43 的表达以及间隙连接的形成，这是心肌中电脉冲传播所必需的。然而，在任何测试的方案中都没有观察到自发的细胞收缩。
5-氮杂胞苷诱导提供了一种有效的心肌细胞分化，类似于 Planat-Bénard 培养基获得的结果。因此，5-氮杂胞苷是最简单、最快和成本最低的细胞分化方案。
