LAUSR

The common aldehyde dehydrogenase 2 (ALDH2) alcohol flushing variant known as ALDH2*2 affects ∼8% of the world’s population. Even in heterozygous carriers, this missense variant leads to a severe loss of ALDH2 enzymatic activity and has been linked to an increased risk of coronary artery disease (CAD). Endothelial cell (EC) dysfunction plays a determining role in all stages of CAD pathogenesis, including early-onset CAD. However, the contribution of ALDH2*2 to EC dysfunction and its relation to CAD are not fully understood. In a large genome-wide association study (GWAS) from Biobank Japan, ALDH2*2 was found to be one of the strongest single-nucleotide polymorphisms associated with CAD. Clinical assessment of endothelial function showed that human participants carrying ALDH2*2 exhibited impaired vasodilation after light alcohol drinking. Using human induced pluripotent stem cell–derived ECs (iPSC-ECs) and CRISPR-Cas9–corrected ALDH2*2 iPSC-ECs, we modeled ALDH2*2-induced EC dysfunction in vitro, demonstrating an increase in oxidative stress and inflammatory markers and a decrease in nitric oxide (NO) production and tube formation capacity, which was further exacerbated by ethanol exposure. We subsequently found that sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin mitigated ALDH2*2-associated EC dysfunction. Studies in ALDH2*2 knock-in mice further demonstrated that empagliflozin attenuated ALDH2*2-mediated vascular dysfunction in vivo. Mechanistically, empagliflozin inhibited Na+/H+-exchanger 1 (NHE-1) and activated AKT kinase and endothelial NO synthase (eNOS) pathways to ameliorate ALDH2*2-induced EC dysfunction. Together, our results suggest that ALDH2*2 induces EC dysfunction and that SGLT2i may potentially be used as a preventative measure against CAD for ALDH2*2 carriers. Description ALDH2*2 iPSC-ECs recapitulate endothelial dysfunction in ALDH2*2 carriers, and SGLT2i could be a preventative therapy. Sobering up the endothelium Endothelial dysfunction is a well-known contributor to coronary artery disease (CAD), the leading cause of mortality worldwide. Guo et al. now show that the aldehyde dehydrogenase 2 genetic polymorphism ALDH2*2 contributes to impaired vascular function in humans by increasing oxidative stress and inflammation in the endothelium. They also report that alcohol consumption can exacerbate these effects. In contrast, the diabetes drug empagliflozin (a sodium-glucose transporter 2 inhibitor) improved endothelial function in ALDH2*2 human iPSC and mouse models of alcohol exposure and diabetes. These findings suggest that alcohol consumption should be considered with caution in ALDH2*2 carriers and that empagliflozin might potentially mitigate risk for CAD in this population.—AW