NFATc1通过Wnt/β-catenin信号通路调控猪骨骼肌纤维类型决定的分子机理

Skeletal muscle fiber types are regulated by many factors and signaling pathways. Studies show that NFATc1 and Wnt/β-catenin signaling pathway are both involved in the regulation of muscle fiber types, and NFATc1 may exert its functions through Wnt/beta-catenin signaling pathway. In present study, we use satellite cells as experimental material. We will study the effects on skeletal muscle fiber types by increasing or reducing the expression of NFATc1 and β-catenin. Next, we will try to analysis the effects of NFATc1 on the expression, distribution and transcription activity of β-catenin by the means of western blotting and immunocytochemistry. Further, we will study the interaction between NFATc1 and the key components of Wnt/β-catenin signaling pathway via luciferase assay and the GST-pulldown technology. Finally, our results would contribute to illustrating the mechanism of NFATc1 and Wnt/β-catenin in regulating muscle fiber types for pork quality improvement.

骨骼肌纤维类型受多种因子和信号通路的调节。研究发现NFATc1与Wnt/β-catenin信号通路均参与肌纤维类型的调控，并且NFATc1可能通过Wnt/β-catenin信号通路来发挥作用。本项目拟以猪骨骼肌卫星细胞为材料，通过高表达或干扰NFATc1及β-catenin分别研究其对肌纤维类型的影响；采用Western blotting、细胞免疫化学方法确定NFATc1对β-catenin表达、分布及转录活性的影响；利用荧光素酶报告基因和GST-pulldown等技术验证NFATc1与Wnt/β-catenin信号通路关键因子的相互作用。揭示NFATc1与 Wnt/β-catenin信号通路调控猪骨骼肌纤维类型决定的分子机理，为改善肉品质提供理论依据。

骨骼肌纤维类型受多种因子和信号通路的调节。研究发现NFATc1与Wnt/β-catenin信号通路均参与肌纤维类型的调控，并且NFATc1可能通过Wnt/β-catenin信号通路来发挥作用。本项目以猪骨骼肌卫星细胞为材料，通过高表达或干扰NFATc1及β-catenin分别研究其对骨骼肌卫星细胞及肌纤维类型的影响；采用Western blotting、细胞免疫化学方法确定NFATc1对β-catenin表达、分布及转录活性的影响。获得以下研究结果:证实了骨骼肌中，NFATc1的表达量与肌纤维类型有密切联系; 阻断CaN/NFAT信号通路抑制了猪骨骼肌卫星细胞的分化，降低MyHC I而提高MyHC IIb mRNA的表达水平; 成功构建NFATc1慢病毒干扰载体和腺病毒超表达载体; 干扰NFATc1，激活了Wnt/β-catenin通路，抑制慢肌分化; 超表达NFATc1抑制Wnt/β-catenin通路，提高MyHC1的表达而降低MyHC2B mRNA的表达; 激活Wnt/ β- catenin 信号通路促进骨骼肌卫星细胞成肌分化，并且诱导其向慢肌分化; EGCG 通过抑制Wnt / β -catenin 信号通路抑制猪骨骼肌卫星细胞的增殖，促进其分化;miR-199a-3p通过抑制AKT/mTOR信号通路抑制C2C12细胞分化。以上结果揭示NFATc1与Wnt/β-catenin信号通调控猪骨骼肌纤维类型决定的分子机理，为改善肉品质提供了理论依据。