| Human aortic smooth muscle cells are insulin resistant at the receptor level but sensitive to IGF1 and IGF2. | |
| | |
MedLine Citation:
|
PMID: 19589910 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Whether insulin, at physiological concentrations, has direct effects on vascular smooth muscle cells (VSMCs) remains controversial. Our aim was to characterize the mechanism for insulin resistance in VSMCs. For comparison, the effects of IGF1 and IGF2 were also studied. Cultured human aortic smooth muscle cells (HASMC) were used. Receptor mRNA was analyzed by quantitative reverse transcription PCR and receptor protein by ELISA and western blot. Biological effects were studied by thymidine incorporation and glucose accumulation. In HASMC, both mRNA and protein expression of IGF1 receptors (IGF1R) were fivefold higher compared to insulin receptor (IR). IR isoform A mRNA was 13-fold more expressed than IR isoform B. IR and IGF1R co-precipitated, indicating the presence of hybrid IR/IGF1R. Phosphorylation of the IGF1R beta-subunit was obtained by IGF1 10(-9)-10(-8) mol/l and IGF2 10(-8) mol/l. IR beta-subunit was phosphorylated by IGF1 10(-8) mol/l but not by insulin. IGF1 stimulated IR substrate-1 and AKT at 10(-8) mol/l and extracellular signal-regulated kinases 1 and 2 at 10(-9)-10(-8) mol/l respectively. IGF1 and 2 at a concentration of 10(-8)-10(-7) mol/l significantly stimulated (3)H-thymidine incorporation, whereas insulin did not. (14)C-Glucose accumulation was stimulated by IGF1 or IGF2 10(-8)-10(-7) mol/l, and also by insulin 10(-7) mol/l. Our results suggest that IGF1R and hybrid IR/IGF1R are activated by physiological concentrations of IGF1 and 2 in HASMC and this propagates downstream signaling and biological effects, while insulin has no effect on its receptor or downstream signaling probably due to a preponderance of IGF1R and incorporation of IR into hybrid IR/IGF1R. |
| | |
Authors:
|
S I Chisalita; G S Johansson; E Liefvendahl; K B??ck; H J Arnqvist |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2009-07-09 |
Journal Detail:
|
Title: Journal of molecular endocrinology Volume: 43 ISSN: 1479-6813 ISO Abbreviation: J. Mol. Endocrinol. Publication Date: 2009 Dec |
Date Detail:
|
Created Date: 2009-11-20 Completed Date: 2010-02-01 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 8902617 Medline TA: J Mol Endocrinol Country: England |
Other Details:
|
Languages: eng Pagination: 231-9 Citation Subset: IM |
Affiliation:
|
Division of Cell Biology, Faculty of Health Sciences, Diabetes Research Centre and Department of Clinical and Experimental Medicine, Link??ping University, 10th Floor, S-581 85 Link??ping, Sweden. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Aorta
/
cytology* Blotting, Western Cells, Cultured Electrophoresis, Polyacrylamide Gel Enzyme-Linked Immunosorbent Assay Humans Insulin / pharmacology* Insulin-Like Growth Factor I / pharmacology* Insulin-Like Growth Factor II / pharmacology* Models, Genetic Muscle, Smooth, Vascular / cytology* Myocytes, Smooth Muscle / drug effects*, metabolism* Phosphorylation / drug effects Protein Isoforms / genetics, metabolism Receptor, IGF Type 1 / genetics, metabolism Receptor, Insulin / genetics, metabolism Reverse Transcriptase Polymerase Chain Reaction |
| Chemical | |
Reg. No./Substance:
|
0/Protein Isoforms; 11061-68-0/Insulin; 67763-96-6/Insulin-Like Growth Factor I; 67763-97-7/Insulin-Like Growth Factor II; EC 2.7.10.1/Receptor, IGF Type 1; EC 2.7.10.1/Receptor, Insulin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The beta104-109 sequence is essential for the secretion of correctly folded single-chain beta alpha ...
Next Document: High incidence of low O6-methylguanine DNA methyltransferase expression in invasive macroadenomas of...