Effects of estrogen and phytoestrogen on myogenesis

骨骼肌是人体内最丰富的组织。男性和女性的身体成分和体型是不同的。性激素被认为是造成骨骼肌质量性别差异的原因，但其具体影响的特征仍不明确。雌激素受体(ER)α和ERβ已在骨骼肌中被发现。虽然雌激素似乎通过ER亚型作用于骨骼肌，但E2和这两种ER亚型在骨骼肌中的作用尚不清楚。在本研究中，我证明了在体外和体内，E2抑制了小鼠C2C12成肌细胞和小鼠卫星细胞的成肌分化，并增加了USP19在骨骼肌中的表达。此外，我证明了USP19是由核ERa诱导的，并通过作为脱泛素酶来抑制肌肉生成。我还分析了两个ERs和ERbeta激动剂在USP19表达中的作用。

Skeletal muscle is the most abundant tissue in the body. Body composition and body size are different between males and females. Sex hormones are thought to be responsible for gender-specific differences in skeletal muscle mass, but their specific effects remain poorly characterized. Estrogen receptor (ER) alpha and ERbeta have been identified in skeletal muscle. Although estrogens seem to act on skeletal muscle through ER isoforms, the roles of E2 and the two ER isoforms in skeletal muscle remain unclear. In this study, I demonstrate that E2 inhibits myogenic differentiation of mouse C2C12 myoblasts and mouse satellite cells and increases the expression of USP19 in skeletal muscle in vitro and in vivo. Furthermore, I demonstrate that USP19 is induced by the nuclear ERalpha and inhibits myogenesis by acting as a deubiquitinating enzyme. I also analyzed the roles of the two ERs and ERbeta agonist in USP19 expression.