Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
Gen Comp Endocrinol. 2010 Jul 1;167(3):344-51. doi: 10.1016/j.ygcen.2010.04.009. Epub 2010 Apr 18.
The insulin-like growth factor (IGF) signaling pathway consists of multiple IGF ligands, IGF receptors, and IGF-binding proteins (IGFBPs). Studies in a variety of animal and cellular systems suggest that the IGF signaling pathway plays a key role in regulating skeletal muscle growth, differentiation, and in maintaining homeostasis of the adult muscle tissues. Intriguingly, IGFs stimulate both myoblast proliferation and differentiation, which are two mutually exclusive biological events during myogenesis. Both of these actions are mediated through the same IGF-1 receptor. Recent studies have shed new insights into the molecular mechanisms underlying these paradoxical actions of IGFs in muscle cells. In this article, we provide a brief review of our current understanding of the IGF signaling system and discuss recent findings on how local oxygen availability and IGFBPs act to specify IGF actions in muscle cells.
胰岛素样生长因子 (IGF) 信号通路由多种 IGF 配体、IGF 受体和 IGF 结合蛋白 (IGFBPs) 组成。在多种动物和细胞系统中的研究表明，IGF 信号通路在调节骨骼肌生长、分化以及维持成年肌肉组织的内稳态方面发挥着关键作用。有趣的是，IGFs 既能刺激成肌细胞增殖，又能刺激其分化，而这两个过程在成肌发生过程中是相互排斥的。这两种作用都是通过相同的 IGF-1 受体介导的。最近的研究为 IGF 在肌肉细胞中的这些矛盾作用的分子机制提供了新的见解。本文简要综述了我们目前对 IGF 信号系统的认识，并讨论了最近关于局部氧供应和 IGFBPs 如何作用以特异性调节 IGF 在肌肉细胞中的作用的发现。
