NADPH Oxidase Mechanisms in Cardiovascular Dysfunction

NADPH oxidases (NOX enzymes) are dedicated generators of reactive oxygen species (ROS) whose regulated activity underpins normal vascular signalling yet, when dysregulated, drives cardiovascular pathology. In endothelial cells, NOX-derived ROS modulate nitric oxide bioavailability, influencing vasodilation, barrier integrity and inflammatory responses. In vascular smooth muscle cells (VSMCs), isoform-specific activation of NOX1, NOX2 and NOX4 orchestrates redox-sensitive pathways that control proliferation, migration and extracellular matrix remodelling. Excessive ROS production fosters endothelial dysfunction, promotes VSMC hyperplasia and facilitates neointimal formation, ultimately contributing to hypertension, atherosclerosis and restenosis. Recent structural and biochemical advances have elucidated the conformational transitions and electron-transfer pathways that underpin NOX activation, calcium-dependent regulation and substrate specificity. These insights have opened routes to isoform-targeted therapies aimed at restoring redox balance without impairing physiological ROS signalling.

Research from Nature Portfolio

Structural studies using cryogenic electron microscopy have captured full-length human NOX5 in apo and calcium-bound states, revealing how calcium binding to the EF-hand domains enhances NADPH dynamics and facilitates electron flow through FAD to the oxygen-reducing centre. A zinc-binding motif was identified as critical for stabilising the active conformation and fine-tuning superoxide output. Complementary work on a bacterial homologue, SpNOX, has provided high-resolution snapshots of substrate-free, NADH- and NADPH-bound forms, elucidating a hydride-transfer mechanism regulated by key aromatic residues. These bacterial structures serve as simplified models for the electron-transfer pathway, highlighting conserved catalytic features and informing the design of inhibitors that may translate to mammalian NOX isoforms implicated in cardiovascular dysfunction.

NADPH Oxidase Mechanisms in Cardiovascular Dysfunction publication trend

The graph below shows the total number of articles in nadph oxidase mechanisms in cardiovascular dysfunction across all publications each year (not limited to Nature Index journals).

Technical terms

NADPH oxidase: A family of membrane-associated enzymes that transfer electrons from NADPH to molecular oxygen, producing superoxide or hydrogen peroxide.

Reactive oxygen species (ROS): Chemically reactive molecules derived from oxygen, including superoxide and hydrogen peroxide, involved in cell signalling and oxidative damage.

Endothelial dysfunction: Impairment of the vascular endothelium characterised by reduced nitric oxide bioavailability, enhanced permeability and a pro-inflammatory state.

Vascular smooth muscle cell (VSMC) hyperplasia: Pathological proliferation and accumulation of VSMCs within the vessel wall, contributing to neointima formation and vessel narrowing.

Electron-transfer pathway: Series of redox steps within NOX enzymes whereby electrons move from NADPH through flavin and haem cofactors to molecular oxygen.

References

1. Structural basis of human NOX5 activation. Nature Communications (2024).
2. Phospholipase C-β3 is dispensable for vascular constriction but indispensable for vascular hyperplasia. Experimental & Molecular Medicine (2024).
3. Structural and mechanistic insights into Streptococcus pneumoniae NADPH oxidase. Nature Structural & Molecular Biology (2024).
4. Endothelial Dysfunction: Is There a Hyperglycemia-Induced Imbalance of NOX and NOS?. International Journal of Molecular Sciences (2019).