IRX3对猪骨骼肌卫星细胞增殖和分化的作用及其机理研究

The number of myofibers is closely related with the potential of meat yield. The number of muscle fibers in animal skeletal muscle is determined by the degree of satellite cell proliferation and differentiation. In addition to be associated with the regulation of energy metabolism, mitochondria is involved in the muscle cell proliferation and differentiation, signal transduction and cell apoptosis process. IRX3 is a member of the Iroquois homeobox gene family，which represses energy dissipation of primary adipocytes by negatively regulating mitochondrial energy metabolism . However, the effect of IRX3 on skeletal muscle has not reported. In this project, IRX3 over-expressing and knocking-down satellite cells will be established to to explore the effect of IRX3 on satellite cell proliferation and differentiation, mitochondrial development and energy metabolism , myogenic factors expression with the methods of MTT,flow cytometry,mitochondrial enzyme activity and energy metabolism measurement, Real-time PCR and western blot.In addition, efforts will be focused on the elucidation of molecular action mechanism of IRX3 during myogenesis by regulating mitochondrial development and energy metabolism , which would improve our understanding of the theoretical basis for the genetic in pigs and nutritional regulation to enhance the meat production potential.

肌纤维数量与猪的产肉潜力及生长速度密切相关。骨骼肌卫星细胞的分裂与增殖程度决定了骨骼肌纤维生长总量的变化。线粒体除了调控肌肉组织能量代谢外，还参与肌细胞的增殖与分化、信号传导及细胞程序化凋亡等过程。易洛魁族同源盒3(iroquois homeobox 3，IRX3)作为脂肪细胞的能量开关，能够负调控线粒体的能量代谢降低细胞中的能量消耗，但在骨骼肌中的作用却未见报道。本项目通过在猪骨骼肌卫星细胞中超表达和沉默IRX3基因，采用MTT法、流式细胞术、线粒体酶活及能量代谢测定法、荧光定量PCR和western blot等技术手段，研究IRX3对猪骨骼肌卫星细胞增殖与分化、线粒体发育与能量代谢及生肌因子的表达量的影响，并着重从调节线粒体发育及其能量代谢的角度探讨IRX3在生肌过程中的分子作用机制，为以提高产肉潜力为目标的遗传改良和营养调控提供理论依据。