活化T细胞核因子3(Nuclear factor of activated T cells 3,NFATc3)是NFAT家族的重要成员,在肌纤维类型转换中具有重要的作用。为探讨NFATc3 mRNA在不同品种鸡不同类型肌肉中的表达情况,以生长速度具有较大差异的清远麻鸡和隐性白羽鸡...活化T细胞核因子3(Nuclear factor of activated T cells 3,NFATc3)是NFAT家族的重要成员,在肌纤维类型转换中具有重要的作用。为探讨NFATc3 mRNA在不同品种鸡不同类型肌肉中的表达情况,以生长速度具有较大差异的清远麻鸡和隐性白羽鸡为材料,采用实时荧光定量PCR方法,检测不同发育时期趾长伸肌和比目鱼肌中NFATc3 mRNA的表达情况。结果发现,NFATc3 mRNA在两个品种骨骼肌的变化趋势基本一致,1日龄时,NFATc3在趾长伸肌和比目鱼肌中的表达量都较高,7日龄时显著下降,21日龄时出现上升,之后表达量趋于平稳;品种间比较,比目鱼肌中在21、49日龄时,清远麻鸡的基因表达量显著高于隐性白羽鸡(P<0.05),趾长伸肌中则在1、21日龄时,清远麻鸡的基因表达量显著高于隐性白羽鸡(P<0.05);同一品种不同类型肌肉间比较,总体上都是趾长伸肌的表达量高于比目鱼肌。提示,鸡骨骼肌中NFATc3 mRNA表达变化规律不存在品种差异,NFATc3可能在鸡不同类型肌肉肌纤维的发育中起重要作用。展开更多
ABSTRACT The molecular signaling pathway linked to hyper-trophy of the anti-gravity/postural soleus muscle af-ter mechanical overloading has not been identified. Using Western blot and immunohistochemical analy-ses, w...ABSTRACT The molecular signaling pathway linked to hyper-trophy of the anti-gravity/postural soleus muscle af-ter mechanical overloading has not been identified. Using Western blot and immunohistochemical analy-ses, we investigated whether the amounts of NFATc3, GSK-3?, NFATc1, and neonatal MHC change in the mechanically overloaded soleus muscle after cyc-losporine A (CsA) treatment. Adult male ICR mice were subjected to a surgical ablation of the gas-trocnemius muscle and treated with either CsA (25 mg/Kg) or vehicle once daily. They were sacrificed at 2, 4, 7, 10, and 14 days post-injury. Mechanical over-loading resulted in a significant increase in the wet weight and the cross-sectional area of slow and fast fibers of the soleus muscle in placebo-treated mice but not CsA-treated mice. After 4 days of mechanical overloading, we observed a similar co-localization of neonatal MHC and NFATc3 in several myotubes of both mice. The placebo-treated mice possessed larger myotubes with neonatal MHC than CsA-treated mice. At 7 days, mechanical overloading induced marked expression of neonatal MHC in myotubes and/or myofibers. Such neonatal MHC-positive fibers emerged less often in the hypertrophied soleus mus-cle subjected to treatment with CsA. CsA treatment did not significantly change the amount of GSK-3? protein in the soleus muscle. The modulation of growth in neonatal MHC-positive myofibers by CsA treatment may inhibit the hypertrophic process in the soleus muscle after mechanical overloading.展开更多
文摘ABSTRACT The molecular signaling pathway linked to hyper-trophy of the anti-gravity/postural soleus muscle af-ter mechanical overloading has not been identified. Using Western blot and immunohistochemical analy-ses, we investigated whether the amounts of NFATc3, GSK-3?, NFATc1, and neonatal MHC change in the mechanically overloaded soleus muscle after cyc-losporine A (CsA) treatment. Adult male ICR mice were subjected to a surgical ablation of the gas-trocnemius muscle and treated with either CsA (25 mg/Kg) or vehicle once daily. They were sacrificed at 2, 4, 7, 10, and 14 days post-injury. Mechanical over-loading resulted in a significant increase in the wet weight and the cross-sectional area of slow and fast fibers of the soleus muscle in placebo-treated mice but not CsA-treated mice. After 4 days of mechanical overloading, we observed a similar co-localization of neonatal MHC and NFATc3 in several myotubes of both mice. The placebo-treated mice possessed larger myotubes with neonatal MHC than CsA-treated mice. At 7 days, mechanical overloading induced marked expression of neonatal MHC in myotubes and/or myofibers. Such neonatal MHC-positive fibers emerged less often in the hypertrophied soleus mus-cle subjected to treatment with CsA. CsA treatment did not significantly change the amount of GSK-3? protein in the soleus muscle. The modulation of growth in neonatal MHC-positive myofibers by CsA treatment may inhibit the hypertrophic process in the soleus muscle after mechanical overloading.
