1. Novel Paracrine Action of Endothelium enhances Glucose Uptake in Muscle and Fat
- Author
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Karen E Hemmings, Natalie J Haywood, Katherine I Bridge, Andrew Walker, Hema Viswambharan, Katie J. Simmons, Richard M Cubbon, Karen E. Porter, Ajay M. Shah, Jane Brown, David J. Beech, Emily R. Clark, Natallia Makava, Mark T. Kearney, Yilizila Abudushalamu, Khalid M. Naseem, Stephen B. Wheatcroft, Helen Imrie, Anna Skromna, V Kate Gatenby, Naima Endesh, Nadira Yuldasheva, Piruthivi Sukumar, T. Simon Futers, and Paul A. Cordell
- Subjects
Physiology ,medicine.medical_treatment ,Glucose uptake ,Type 2 diabetes ,030204 cardiovascular system & hematology ,Receptor, IGF Type 1 ,Mice ,0302 clinical medicine ,Insulin-Like Growth Factor I ,glucose ,Cells, Cultured ,Original Research ,0303 health sciences ,NADPH oxidase ,biology ,Chemistry ,catalase ,3. Good health ,microRNAs ,Endothelial stem cell ,medicine.anatomical_structure ,Adipose Tissue ,NADPH Oxidase 4 ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,muscles ,Cardiology and Cardiovascular Medicine ,medicine.medical_specialty ,insulin ,Endothelium ,endothelium ,fasting ,03 medical and health sciences ,Insulin resistance ,Internal medicine ,Paracrine Communication ,medicine ,Animals ,Humans ,Muscle, Skeletal ,030304 developmental biology ,Insulin ,Hydrogen Peroxide ,medicine.disease ,Mice, Inbred C57BL ,Insulin receptor ,Endocrinology ,Diabetes Mellitus, Type 2 ,biology.protein ,Endothelium, Vascular - Abstract
Supplemental Digital Content is available in the text., Rationale: A hallmark of type 2 diabetes is insulin resistance, which leads to increased endothelial cell (EC) production of superoxide and a simultaneous reduction in the availability of the vasoprotective signaling radical NO. We recently demonstrated in preclinical models that type 2 diabetes simultaneously causes resistance to IGF-1 (insulin-like growth factor-1)–mediated glucose lowering and endothelial NO release. Objective: To examine the effect of insulin and IGF-1 resistance specifically in ECs in vivo. Methods and Results: We generated mice expressing mIGF-1Rs (mouse IGF-1 receptors), which form nonfunctioning hybrid receptors with native IRs (insulin receptors) and IGF-1R, directed to ECs under control of the Tie2 promoter-enhancer. Despite EC insulin and IGF-1 resistance, mIGFREO (mutant IGF-1R EC overexpressing) mice had enhanced insulin and IGF-1–mediated systemic glucose disposal, lower fasting free fatty acids, and triglycerides. In hyperinsulinemic-euglycemic clamp studies, mIGFREO had increased glucose disposal and increased glucose uptake into muscle and fat, in response to insulin. mIGFREO had increased Nox (NADPH oxidase)-4 expression due to reduced expression of the microRNA, miR-25. Consistent with increased Nox4, mIGFREO ECs generated increased hydrogen peroxide (H2O2), with no increase in superoxide. Treatment with catalase—a H2O2 dismutase—restored insulin tolerance to WT (wild type) levels in mIGFREO. Conclusions: Combined insulin and IGF-1 resistance restricted to the endothelium leads to a potentially favorable adaptation in contrast to pure insulin resistance, with increased Nox4-derived H2O2 generation mediating enhanced whole-body insulin sensitivity.
- Published
- 2021