Zhang Zhenhe, Zhao Lidan D, Johnson Sally E, Rhoads Michelle L, Jiang Honglin, Rhoads Robert P
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA.
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA.
Domest Anim Endocrinol. 2019 Jan;66:1-13. doi: 10.1016/j.domaniend.2018.07.003. Epub 2018 Aug 3.
Sex steroid hormones are used in the meat industry due to their ability to regulate muscle hypertrophy. However, the mechanisms underlying their action are not fully elucidated. Recent reports demonstrate that steroid hormones increase oxytocin (OXT) expression in skeletal muscle, indicating that OXT may play a role in satellite cell activity. This hypothesis was tested using steroid hormones (17β-estradiol [E2]; trenbolone acetate [TBA]), tamoxifen (TAM), OXT, and atosiban (A: OXT receptor inhibitor) applied to bovine satellite cells (BSCs) to investigate BSC regulation by OXT. Oxytocin alone increased fusion index (P < 0.05) but not BSC proliferation. Oxytocin reduced (P < 0.05) apoptotic nuclei and stimulated migration rate (P < 0.05). Similarly, E2 and TBA increased (P < 0.05) BSC proliferation rate, fusion index, and migration and decreased (P < 0.05) apoptotic nuclei. 17β-Estradiol or TBA supplemented with A had lower (P < 0.05) BSC proliferation rate, fusion index, and migration and more (P < 0.05) apoptotic nuclei compared with E2 or TBA alone. Furthermore, OXT expression increased (P < 0.05) in E2 or TBA-treated proliferating BSC. Oxytocin, E2, and TBA increased (P < 0.05) MyoD and MyoG expression in proliferating BSC. During BSC differentiation, OXT expression increased (P < 0.05) with E2 or TBA treatments. MyoG expression increased (P < 0.05) in OXT, E2, and TBA compared with control. However, A, OXT + A, TAM, TAM + OXT, E2 + TAM, E2 + A, and TBA + A decreased (P < 0.05) MyoG expression during BSC differentiation. These results indicate that OXT is involved in steroid hormone-stimulated BSC activity.
由于具有调节肌肉肥大的能力，性类固醇激素被用于肉类行业。然而，其作用的潜在机制尚未完全阐明。最近的报告表明，类固醇激素会增加骨骼肌中催产素（OXT）的表达，这表明OXT可能在卫星细胞活性中发挥作用。本研究使用类固醇激素（17β-雌二醇 [E2]；醋酸群勃龙 [TBA]）、他莫昔芬（TAM）、OXT和阿托西班（A：OXT受体抑制剂）作用于牛卫星细胞（BSC），以研究OXT对BSC的调节作用，从而验证这一假设。单独使用OXT可增加融合指数（P < 0.05），但对BSC增殖无影响。OXT可减少（P < 0.05）凋亡细胞核数量并刺激迁移率（P < 0.05）。同样，E2和TBA可增加（P < 0.05）BSC增殖率、融合指数和迁移率，并减少（P < 0.05）凋亡细胞核数量。与单独使用E2或TBA相比，添加A的17β-雌二醇或TBA的BSC增殖率、融合指数和迁移率较低（P < 0.05），凋亡细胞核数量更多（P < 0.05）。此外，在E2或TBA处理的增殖性BSC中，OXT表达增加（P < 0.05）。OXT、E2和TBA可增加（P < 0.05）增殖性BSC中MyoD和MyoG的表达。在BSC分化过程中，E2或TBA处理可使OXT表达增加（P < 0.05）。与对照组相比，OXT、E2和TBA处理组中MyoG表达增加（P < 0.05）。然而，在BSC分化过程中，A、OXT + A、TAM、TAM + OXT、E2 + TAM、E2 + A和TBA + A可降低（P < 0.05）MyoG表达。这些结果表明，OXT参与了类固醇激素刺激的BSC活性。
