肌生成是控制骨骼肌发育和稳态的关键过程。铅(Pb)暴露会损害骨骼的发育和健康,这减缓了儿童的成长。然而,铅对骨骼肌发育的确切影响尚不清楚。在这项研究中,C2C12细胞通常用作肌肉再生的体外模型,因为它们能够从增殖期转变为分化的肌纤维。采用1、5和10μMPb的剂量来研究Pb对C2C12增殖和分化的毒性。首先,检测到Pb对细胞活力的影响,结果表明,5μM和10μMPb暴露会降低细胞活力,1μMPb暴露对细胞活力无明显影响。然后,1-10μMPb暴露严重降低了C2C12成肌细胞的分化,随着成肌分化标记基因表达的减少,包括肌肉肌酸激酶(MCK),肌球蛋白重链4(MYH4),Myogenin(MYOG),肌源性分化(MYOD)。更重要的是,发现表观遗传修饰组蛋白脱乙酰酶-2(HDAC2)在Pb暴露于C2C12成肌细胞后上调。进一步的研究最终表明,HDAC2的敲除改善了Pb损伤的C2C12成肌细胞的分化,表明HDAC2在Pb诱导的C2C12成肌细胞分化缺陷中起着至关重要的作用。总之,这些结果表明,铅暴露通过调节HDAC2抑制C2C12成肌细胞的分化。
Myogenesis is a crucial process governing skeletal muscle development and homeostasis. Lead (Pb) exposure impaired the development and the health of bones, which slows the growth of children. However, it is far from clear what exactly the effects of Pb on skeletal muscle development are. In this study, C2C12 cells are commonly used as an in vitro model of muscle regeneration due to their ability to transition from a proliferative phase into differentiated myofibers. The dose of 1, 5, and 10 μM Pb were adopted to study the toxicity of Pb on C2C12 proliferation and differentiation. First, the effects of Pb on cell viability were detected and the results demonstrated that 5 μM and 10 μM Pb exposure decreased cell viability, while 1 μM Pb exposure has no obvious effects on cell viability. Then, 1-10 μM Pb exposure seriously reduced the C2C12 myoblasts differentiation, with the decrease of myogenic differentiation marker genes expression, including Muscle creatine kinase (MCK), Myosin Heavy Chain 4 (MYH4), Myogenin (MYOG), Myogenic Differentiation (MYOD). What\'s more, it was found that the epigenetic modifier histone deacetylase-2 (HDAC2) was upregulated after Pb exposure on C2C12 myoblasts. Further studies conclusively showed knockdown of HDAC2 ameliorated Pb-damaged C2C12 myoblasts differentiation, indicating HDAC2 plays a vital role in the Pb-induced C2C12 myoblasts differentiation deficits. In summary, these results demonstrated that Pb exposure inhibited C2C12 myoblasts differentiation by regulating HDAC2.