IGF-Ⅰ能够促进细胞的增殖分化和代谢过程,而其表达是受STAT介导的,该通路最终受到生长激素(GH)的调控。生长激素与生长激素受体结合激活JAK家族,使得STAT家族成员,特别是STAT5磷酸化。磷酸化的STAT5进入细胞核内,与IGF-Ⅰ基因上的STAT5结合位点结合,激活胰岛素样生长因子-Ⅰ(IGF-Ⅰ)的表达,IGF-Ⅰ再通过血液循环到达机体的局部组织,促进组织细胞的生长和分化。作者对动物生长轴中STAT和IGF-Ⅰ的组成、功能以及STAT调控IGF-Ⅰ表达的分子机理的研究进展作一综述。
Insulin-like growth factor-Ⅰ(IGF-Ⅰ) is an important endocrine and paracrine regulator of cell proliferation and metabolism.GH signaling is initiated by binding of two distinct sites of the GH molecule to two GHR monomers,which is followed by receptor dimerization and activation of Janus kinase 2(JAK-2) tyrosine kinase,then induces MAPKs,tyrosine phosphorylation of GHR and other intracellular proteins such as insulin receptor substrate-1 and signal transducers and activators of transcription(STAT1,STAT3,and STAT5).The activated STAT proteins accumulate in the nucleus to drive the transcription of IGFs,and IGFs translocate to local tissue by blood circulation and promote the development and differentiation of tissues and cells.GH mediated by IGF-Ⅰ regulates animal growth and cell differentiation.We will discuss the constitution and function of STAT and IGF-Ⅰ and relationship between both of them in animal's growth axis in this review.