Oliveira Taissa Neustadt, Possidonio Ana Claudia, Soares Carolina Pontes, Ayres Rodrigo, Costa Manoel Luis, Quintas Luis Eduardo Menezes, Mermelstein Cláudia
Laboratório de Diferenciação Muscular e Citoesqueleto, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Laboratório de Farmacologia Bioquímica e Molecular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
PLoS One. 2015 Mar 16;10(3):e0120940. doi: 10.1371/journal.pone.0120940. eCollection 2015.
The formation of a vertebrate skeletal muscle fiber involves a series of sequential and interdependent events that occurs during embryogenesis. One of these events is myoblast fusion which has been widely studied, yet not completely understood. It was previously shown that during myoblast fusion there is an increase in the expression of Na+/K+-ATPase. This fact prompted us to search for a role of the enzyme during chick in vitro skeletal myogenesis. Chick myogenic cells were treated with the Na+/K+-ATPase inhibitor ouabain in four different concentrations (0.01-10 μM) and analyzed. Our results show that 0.01, 0.1 and 1 μM ouabain did not induce changes in cell viability, whereas 10 μM induced a 45% decrease. We also observed a reduction in the number and thickness of multinucleated myotubes and a decrease in the number of myoblasts after 10 μM ouabain treatment. We tested the involvement of MEK-ERK and p38 signaling pathways in the ouabain-induced effects during myogenesis, since both pathways have been associated with Na+/K+-ATPase. The MEK-ERK inhibitor U0126 alone did not alter cell viability and did not change ouabain effect. The p38 inhibitor SB202190 alone or together with 10 μM ouabain did not alter cell viability. Our results show that the 10 μM ouabain effects in myofiber formation do not involve the MEK-ERK or the p38 signaling pathways, and therefore are probably related to the pump activity function of the Na+/K+-ATPase.
脊椎动物骨骼肌纤维的形成涉及胚胎发育过程中一系列连续且相互依存的事件。其中一个事件是成肌细胞融合，这一过程已得到广泛研究，但尚未完全理解。先前的研究表明，在成肌细胞融合过程中，Na+/K+-ATP酶的表达会增加。这一事实促使我们探寻该酶在鸡体外骨骼肌生成过程中的作用。用四种不同浓度（0.01 - 10 μM）的Na+/K+-ATP酶抑制剂哇巴因处理鸡的成肌细胞并进行分析。我们的结果显示，0.01、0.1和1 μM的哇巴因未引起细胞活力的变化，而10 μM的哇巴因则导致细胞活力下降了45%。我们还观察到，在10 μM哇巴因处理后，多核肌管的数量和厚度减少，成肌细胞数量也减少。由于MEK-ERK和p38信号通路都与Na+/K+-ATP酶有关，我们测试了它们在哇巴因诱导的肌生成效应中的作用。单独使用MEK-ERK抑制剂U0126不会改变细胞活力，也不会改变哇巴因的效应。单独使用p38抑制剂SB202190或与10 μM哇巴因一起使用都不会改变细胞活力。我们的结果表明，10 μM哇巴因对肌纤维形成的影响不涉及MEK-ERK或p38信号通路，因此可能与Na+/K+-ATP酶的泵活性功能有关。
