Field Marshal Earl Alexander Professor of Cardiovascular Medicine
- Director, NIHR Oxford Biomedical Research Centre
- Associate Head of Medical Sciences Division (Clinical Research)
Nitric oxide and redox signalling in cardiovascular disease
We aim to understand how early changes in the endothelium and vascular wall are related to the initiation and development of vascular diseases, with a particular focus on nitric oxide signalling.
Diabetes, high cholesterol, smoking and high blood pressure are all associated with abnormalities in the function of the endothelium, the single-cell lining of blood vessels. Of particular significance are abnormalities in the action of nitric oxide (NO), one of several important molecules produced in the endothelium that help to maintain the health of the blood vessel wall. These abnormalities accelerate the processes that lead to vascular disease, including inflammation, thrombosis and atherosclerotic plaque formation.
Production of NO, by nitric oxide synthase enzymes, is highly regulated and depends on the co-factor tetrahydrobiopterin, which is made within endothelial cells. Once NO is produced, it interacts with molecular targets in the cell, but is rapidly inactivated by reactive oxygen species (ROS). Nitric oxide synthases can produce ROS as well as NO, the balance between the two determining the biological actions and pathological importance of these pathways.
In previous work, we have used both clinical studies and experimental models to explore the role of endothelial nitric oxide synthase and its regulation by tetrahydrobiopterin in vascular disease, in particular the inflammation associated with atherosclerotic plaque formation. We have developed transgenic models to increase tetrahydrobiopterin levels in the endothelium and other cell types, by overexpression of GTP cyclohydrolase 1 (GTPCH), the rate-limiting enzyme in its synthesis. We have also generated targeted knockouts of GTPCH, to work out how tetrahydrobiopterin is involved in normal function in the cardiovascular system elsewhere.
In studies of patients with diabetes and coronary artery disease, we have examined changes in endothelial function, and nitric oxide and tetrahydrobiopterin levels, and how these relate to the clinical features of disease. We have carried out clinical trials of treatments to increase tetrahydrobiopterin levels and improve endothelial function.
Tracking Monocyte Recruitment and Macrophage Accumulation in Atherosclerotic Plaque Progression Using a Novel hCD68GFP/ApoE-/- Reporter Mouse-Brief Report.
McNeill E. et al, (2017), Arterioscler Thromb Vasc Biol, 37, 258 - 263
A Key Role for Tetrahydrobiopterin-Dependent Endothelial NOS Regulation in Vascular Resistance Arteries: Studies in Endothelial Cell Tetrahydrobiopterin-Deficient Mice
Chuaiphichai S. et al, (2017), British Journal of Pharmacology
A Novel Role for Endothelial Tetrahydrobiopterin in Mitochondrial Redox Balance
Bailey JD. et al, (2017), Free Radical Biology and Medicine
Dual quantitative coronary angiography accurately quantifies intracoronary thrombotic burden in patients with acute coronary syndrome: Comparison with optical coherence tomography imaging.
Vergallo R. et al, (2019), Int J Cardiol, 292, 25 - 31
Adipose tissue-derived WNT5A regulates vascular redox signaling in obesity via USP17//RAC1-mediated activation of NADPH oxidases
AKOUMIANAKIS I. et al, (2019), Science Translational Medicine
A novel machine learning-derived radiotranscriptomic signature of perivascular fat improves cardiac risk prediction using coronary CT angiography
OIKONOMOU E. et al, (2019), European Heart Journal
Safety of Rotational Atherectomy Using the Radial Access in Patients With Severe Aortic Stenosis.
Kotronias RA. et al, (2019), Am J Cardiol, 124, 381 - 388
THYMOSIN B4 MEDIATES VASCULAR PROTECTION VIA REGULATION OF LOW DENSITY LIPOPROTEIN RECEPTOR RELATED PROTEIN 1 (LRP1)
Munshaw S. et al, (2019), ATHEROSCLEROSIS, 287, E3 - E4