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Differentiated Mouse Adipocytes in Primary Culture: A Model of Insulin Resistance
Published on: February 17, 2023
Global IRS-1 phosphorylation analysis in insulin resistance
P Langlais1, Z Yi, J Finlayson
1Center for Metabolic and Vascular Biology, School of Life Science, Arizona State University, ISTB1, 550 E. Orange St, Tempe, AZ 85287, USA.
Diabetologia
|August 19, 2011
Summary
Insulin receptor substrate-1 (IRS-1) phosphorylation in human muscle reveals altered basal levels in type 2 diabetes. Insulin
Area of Science:
- Metabolic research
- Molecular biology
- Human physiology
Background:
- Insulin resistance is linked to elevated IRS-1 serine phosphorylation in models, but human in vivo data is scarce.
- Understanding IRS-1 phosphorylation in human muscle is crucial for elucidating insulin resistance mechanisms.
Purpose of the Study:
- To investigate in vivo IRS-1 phosphorylation patterns in human muscle from lean healthy, obese non-diabetic, and type 2 diabetic individuals.
- To assess the impact of insulin infusion on IRS-1 phosphorylation sites in different metabolic states.
Main Methods:
- Utilized high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS).
- Quantified IRS-1 phosphorylation at various sites basally and post-insulin infusion.
- Analyzed vastus lateralis muscle samples from distinct human cohorts.
Main Results:
- Type 2 diabetic patients exhibited increased basal Ser323 and decreased Thr495 IRS-1 phosphorylation.
- Insulin infusion stimulated Ser527 and Ser531 phosphorylation in lean controls.
- Insulin suppressed phosphorylation at Ser348, Thr446, Ser1100, and Ser1142 in a time-dependent manner.
Conclusions:
- The capacity of insulin to modulate specific IRS-1 phosphorylation sites remains largely intact in human insulin resistance.
- Certain IRS-1 phosphorylation sites show altered basal levels in type 2 diabetes.
- Insulin signaling pathways involving IRS-1 phosphorylation are complex and exhibit site-specific regulation in metabolic health and disease.
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