Hema Viswambharan1, Nadira Y Yuldasheva2, Anshuman Sengupta2, Helen Imrie2, Matthew C Gage2, Natalie Haywood2, Andrew M N Walker2, Anna Skromna2, Natallia Makova2, Stacey Galloway2, Pooja Shah2, Piruthivi Sukumar2, Karen E Porter2, Peter J Grant2, Ajay M Shah2, Celio X C Santos2, Jing Li2, David J Beech2, Stephen B Wheatcroft2, Richard M Cubbon2, Mark T Kearney2. 1. From the Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, United Kingdom (H.V., N.Y.Y., A.S., H.I., N.H., A.M.N.W., A.S., N.M., S.G., P. Shah, P. Sukumar, K.E.P., P.J.G., J.L., D.J.B., S.B.W., R.M.C., M.T.K.); Division of Medicine, Department of Metabolism & Experimental Therapeutics, University College London, United Kingdom (M.C.G.); and British Heart Foundation Centre of Research Excellence, King's College London, United Kingdom (A.M.S., C.X.C.S.). h.viswambharan@leeds.ac.uk. 2. From the Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, United Kingdom (H.V., N.Y.Y., A.S., H.I., N.H., A.M.N.W., A.S., N.M., S.G., P. Shah, P. Sukumar, K.E.P., P.J.G., J.L., D.J.B., S.B.W., R.M.C., M.T.K.); Division of Medicine, Department of Metabolism & Experimental Therapeutics, University College London, United Kingdom (M.C.G.); and British Heart Foundation Centre of Research Excellence, King's College London, United Kingdom (A.M.S., C.X.C.S.).
Abstract
RATIONALE: In the endothelium, insulin stimulates endothelial NO synthase (eNOS) to generate the antiatherosclerotic signaling radical NO. Insulin-resistant type 2 diabetes mellitus is associated with reduced NO availability and accelerated atherosclerosis. The effect of enhancing endothelial insulin sensitivity on NO availability is unclear. OBJECTIVE: To answer this question, we generated a mouse with endothelial cell (EC)-specific overexpression of the human insulin receptor (hIRECO) using the Tie2 promoter-enhancer. METHODS AND RESULTS: hIRECO demonstrated significant endothelial dysfunction measured by blunted endothelium-dependent vasorelaxation to acetylcholine, which was normalized by a specific Nox2 NADPH oxidase inhibitor. Insulin-stimulated phosphorylation of protein kinase B was increased in hIRECO EC as was Nox2 NADPH oxidase-dependent generation of superoxide, whereas insulin-stimulated and shear stress-stimulated eNOS activations were blunted. Phosphorylation at the inhibitory residue Y657 of eNOS and expression of proline-rich tyrosine kinase 2 that phosphorylates this residue were significantly higher in hIRECO EC. Inhibition of proline-rich tyrosine kinase 2 improved insulin-induced and shear stress-induced eNOS activation in hIRECO EC. CONCLUSIONS: Enhancing insulin sensitivity specifically in EC leads to a paradoxical decline in endothelial function, mediated by increased tyrosine phosphorylation of eNOS and excess Nox2-derived superoxide. Increased EC insulin sensitivity leads to a proatherosclerotic imbalance between NO and superoxide. Inhibition of proline-rich tyrosine kinase 2 restores insulin-induced and shear stress-induced NO production. This study demonstrates for the first time that increased endothelial insulin sensitivity leads to a proatherosclerotic imbalance between NO and superoxide.
RATIONALE: In the endothelium, insulin stimulates endothelial NO synthase (eNOS) to generate the antiatherosclerotic signaling radical NO. Insulin-resistant type 2 diabetes mellitus is associated with reduced NO availability and accelerated atherosclerosis. The effect of enhancing endothelial insulin sensitivity on NO availability is unclear. OBJECTIVE: To answer this question, we generated a mouse with endothelial cell (EC)-specific overexpression of the human insulin receptor (hIRECO) using the Tie2 promoter-enhancer. METHODS AND RESULTS: hIRECO demonstrated significant endothelial dysfunction measured by blunted endothelium-dependent vasorelaxation to acetylcholine, which was normalized by a specific Nox2 NADPH oxidase inhibitor. Insulin-stimulated phosphorylation of protein kinase B was increased in hIRECO EC as was Nox2 NADPH oxidase-dependent generation of superoxide, whereas insulin-stimulated and shear stress-stimulated eNOS activations were blunted. Phosphorylation at the inhibitory residue Y657 of eNOS and expression of proline-rich tyrosine kinase 2 that phosphorylates this residue were significantly higher in hIRECO EC. Inhibition of proline-rich tyrosine kinase 2 improved insulin-induced and shear stress-induced eNOS activation in hIRECO EC. CONCLUSIONS: Enhancing insulin sensitivity specifically in EC leads to a paradoxical decline in endothelial function, mediated by increased tyrosine phosphorylation of eNOS and excess Nox2-derived superoxide. Increased EC insulin sensitivity leads to a proatherosclerotic imbalance between NO and superoxide. Inhibition of proline-rich tyrosine kinase 2 restores insulin-induced and shear stress-induced NO production. This study demonstrates for the first time that increased endothelial insulin sensitivity leads to a proatherosclerotic imbalance between NO and superoxide.
Authors: Guy Eelen; Pauline de Zeeuw; Lucas Treps; Ulrike Harjes; Brian W Wong; Peter Carmeliet Journal: Physiol Rev Date: 2018-01-01 Impact factor: 37.312
Authors: Samuel J Turvey; Martin J McPhillie; Mark T Kearney; Stephen P Muench; Katie J Simmons; Colin W G Fishwick Journal: RSC Med Chem Date: 2022-02-21
Authors: Anshuman Sengupta; Peysh A Patel; Nadira Y Yuldasheva; Romana S Mughal; Stacey Galloway; Hema Viswambharan; Andrew M N Walker; Amir Aziz; Jessica Smith; Noman Ali; Ben N Mercer; Helen Imrie; Piruthivi Sukumar; Stephen B Wheatcroft; Mark T Kearney; Richard M Cubbon Journal: Endocrinology Date: 2018-08-01 Impact factor: 4.736
Authors: Azhar Maqbool; Nicole T Watt; Natalie Haywood; Hema Viswambharan; Anna Skromna; Natalia Makava; Asjad Visnagri; Heba M Shawer; Katherine Bridge; Shovkat K Muminov; Kathryn Griffin; David J Beech; Stephen B Wheatcroft; Karen E Porter; Katie J Simmons; Piruthivi Sukumar; Ajay M Shah; Richard M Cubbon; Mark T Kearney; Nadira Y Yuldasheva Journal: Am J Physiol Cell Physiol Date: 2020-05-13 Impact factor: 4.249