Molecular dynamics to restore/remodel neuromuscular connections during muscle growth and regeneration

神经肌肉连接的成功再生和重塑是恢复肌纤维收缩生理功能特性的关键。虽然协调这些过程与肌生成本身的时空调节机制尚不清楚，但各种神经因素，包括吸引和排斥轴突引导线索配体及其受体可能参与其中。最近，我们发现卫星细胞，通常位于成熟肌纤维基底层的常驻肌源性干细胞，在体内急性肌肉损伤时，在早期分化期上调分泌的神经化学反应信号蛋白3A (Sema3A) （Tatsumi et al., 2009）。目前的研究表明，在再生肌肉组织中，细胞外上调因子（HGF和FGF2）和下调因子（TGF-β3）浓度的时间协调流行可能会调节Sema3A的表达。通过理解这种生长因子配体驱动的场景，我们将能够设计出专门针对再生运动神经生成的新程序，以确保肌肉的生长和修复，为肉类动物生产、人类运动和健康科学做出贡献，旨在提高身体表现，并为神经肌肉疾病和与年龄相关的肌肉萎缩提供医学治疗

Successful regeneration and remodeling of the neuromuscular connections are critical for restoring functional properties of contractile physiology of muscle fibers. While the spatiotemporal regulatory mechanisms coordinating these processes with myogenesis itself remain unclear, various neural factors including attractive and repulsive axon-guidance cue ligands and their receptors may be involved. Recently, we found that satellite cells, resident myogenic stem cells normally positioned beneath the basal lamina of mature muscle fibers, up-regulate a secreted neural chemorepellent semaphorin 3A (Sema3A) during early-differentiation period, upon acute muscle injury in vivo(Tatsumi et al., 2009). The current study encouraged the possible regulation of Sema3A expression by time-coordinated prevalence of extracellular up-regulator (HGF and FGF2) and down-regulator (TGF-β3) concentrations bathing differentiating satellite cells (myoblasts) in regenerating muscle tissue. By understanding this growth factor ligand-driving scenario, we will be able to design new procedures that specifically target regenerative motoneuritogenesis to ensure muscle growth and repair, contributing to the meat-animal production and human sports and health sciences aimed to enhance physical performance and medical therapies for neuromuscular disorders and age-related muscle atrophy