Hu_2021_Am.J.Physiol.Heart.Circ.Physiol__

Arterial stiffness, a consequence of smoking, is an underlying risk factor of cardiovascular diseases. Epoxyeicosatrienoic acids (EETs), hydrolyzed by soluble epoxide hydrolase (sEH), have beneficial effects against vascular dysfunction. However, the role of sEH knockout in nicotine-induced arterial stiffness was not characterized. We hypothesized that sEH knockout could prevent nicotine-induced arterial stiffness. In the present study, Ephx2 (the gene encodes sEH enzyme) null (Ephx2(-/-)) mice and wild-type (WT) littermate mice were infused with or without nicotine and administered with or without nicotinamide (NAM, SIRT1 inhibitor) simultaneously for four weeks. Nicotine treatment increased sEH expression and activity in the aortas of WT mice. Nicotine infusion significantly induced vascular remodeling, arterial stiffness, and SIRT1 deactivation in WT mice, which was attenuated in Ephx2(-/-) mice without NAM treatment. However, the arterial protective effects were gone in Ephx2(-/-) mice with NAM treatment. In vitro, 11,12-EET treatment attenuated nicotine-induced MMP2 upregulation via SIRT1-mediated YAP deacetylation. In conclusion, sEH knockout attenuated nicotine-induced arterial stiffness and vascular remodeling via SIRT1-induced YAP deacetylation.