Schmid C
Department of Medicine, University Hospital, Zurich, Switzerland.
Cell Biol Int. 1995 May;19(5):445-57. doi: 10.1006/cbir.1995.1088.
The insulin-like growth factors I and II are single chain polypeptides homologous to proinsulin. IGF I and IGF II contribute to cell regulation and stimulate protein synthesis via signaling through type 1 receptors which are homologous to insulin receptors and activate phosphorylation cascades. IGFs enhance the proliferation of chondocytes and the proliferation of their collagen and proteoglycan matrix; IGFs stimulate longitudinal (endochondral) bone growth. Throughout life, IGFs are constitutively expressed ubiquitous factors which help to maintain the survival of differentiated cells, Increased expression is found during growth and tissue repair, Six specific binding proteins, IGFBP 1-6, allow additional tissue compartment specific control of IGF activity; IGFBP production favours storage and IGFBP cleavage leads to activation.
胰岛素样生长因子I和II是与胰岛素原同源的单链多肽。胰岛素样生长因子I和II通过与胰岛素受体同源的1型受体发出信号，激活磷酸化级联反应，从而参与细胞调节并刺激蛋白质合成。胰岛素样生长因子可增强软骨细胞及其胶原蛋白和蛋白聚糖基质的增殖；刺激纵向（软骨内）骨生长。在整个生命过程中，胰岛素样生长因子是组成性表达的普遍存在的因子，有助于维持分化细胞的存活，在生长和组织修复过程中表达增加。六种特异性结合蛋白，即胰岛素样生长因子结合蛋白1-6，可对胰岛素样生长因子的活性进行额外的组织区室特异性控制；胰岛素样生长因子结合蛋白的产生有利于储存，而胰岛素样生长因子结合蛋白的裂解则导致激活。
