IGF-I/insulin hybrid receptors in human endothelial cells
2005 (English)In: Molecular and Cellular Endocrinology, ISSN 0303-7207, E-ISSN 1872-8057, Vol. 229, no 1-2, 31-37 p.Article in journal (Refereed) Published
Vascular complications are common in diabetes. IGF-I receptors (IGF-IR) and insulin receptors (IR) in endothelial cells might respond to altered levels of IGF-I and insulin, resulting in altered endothelial function in diabetes. We therefore studied IGF-IR and IR gene expression, ligand binding, receptor protein, and phosphorylation in human umbilical vein endothelial cells (HUVEC). IGF-IR mRNA was more abundant than IRmRNAin freshly isolatedHUVEC(IGF-IR/IR ratio 7.1±1.5) and in culturedHUVEC(ratio 3.5±0.51). Accordingly, specific binding of 125I-IGF-I (0.64±0.25%) was higher than that of 125I-insulin (0.25±0.09%). Protein was detected for both eceptors and IGF-I/insulin hybrid receptors. IGF-IR phosphorylation was stimulated by 10−10 to 10−8M IGF-I. IR were activated by 10−9 to 10−8M insulin and IGF-I. We conclude that HUVEC express more IGF-IR than IR, and also express hybrid receptors. Both IGF-I and insulin phosphorylate their own receptors but only IGF-I seems to phosphorylate hybrid receptors.
Place, publisher, year, edition, pages
2005. Vol. 229, no 1-2, 31-37 p.
IGF-I receptor; Insulin receptor; Insulin/IGF-I hybrid receptor; Endothelial cells; Human
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-12553DOI: 10.1016/j.mce.2004.10.003ISI: 000226596400005OAI: oai:DiVA.org:liu-12553DiVA: diva2:1692