by Mahmoud H. Elbatreek, Sepideh Sadegh, Elisa Anastasi, Emre Guney, Cristian Nogales, Tim Kacprowski, Ahmed A. Hassan, Andreas Teubner, Po-Hsun Huang, Chien-Yi Hsu, Paul M. H. Schiffers, Ger M. Janssen, Pamela W. M. Kleikers, Anil Wipat, Jan Baumbach, Jo G. R. De Mey, Harald H. H. W. Schmidt
Hypertension is the most important cause of death and disability in the elderly. In 9 out of 10 cases, the molecular cause, however, is unknown. One mechanistic hypothesis involves impaired endothelium-dependent vasodilation through reactive oxygen species (ROS) formation. Indeed, ROS forming NADPH oxidase (Nox) genes associate with hypertension, yet target validation has been negative. We re-investigate this association by molecular network analysis and identify NOX5, not present in rodents, as a sole neighbor to human vasodilatory endothelial nitric oxide (NO) signaling. In hypertensive patients, endothelial microparticles indeed contained higher levels of NOX5—but not NOX1, NOX2, or NOX4—with a bimodal distribution correlating with disease severity. Mechanistically, mice expressing human Nox5 in endothelial cells developed—upon aging—severe systolic hypertension and impaired endothelium-dependent vasodilation due to uncoupled NO synthase (NOS). We conclude that NOX5-induced uncoupling of endothelial NOS is a causal mechanism and theragnostic target of an age-related hypertension endotype. Nox5 knock-in (KI) mice represent the first mechanism-based animal model of hypertension.