Voluntary exercise training caused deleterious effects, including elevated reactive oxygen species production and eNOS uncoupling, in mice lacking endothelial α1AMPK compared to wild-type mice.
Endothelial α1AMPK acts as a critical master switch determining whether the effects of exercise on the vasculature are protective or detrimental.
Voluntary exercise training is an effective way to prevent cardiovascular disease, since it results in increased NO bioavailability and decreased reactive oxygen species (ROS) production. AMP-activated protein kinase (AMPK), especially its α1AMPK subunit, modulates ROS-dependent vascular homeostasis. Since endothelial cells play an important role in exercise-induced changes of vascular signaling, we examined the consequences of endothelial-specific α1AMPK deletion during voluntary exercise training. We generated a mouse strain with specific deletion of α1AMPK in endothelial cells (α1AMPKflox/flox x TekCre+). While voluntary exercise training improved endothelial function in wild-type mice, it had deleterious effects in mice lacking endothelial α1AMPK indicated by elevated reactive oxygen species production (measured by dihydroethidum fluorescence and 3-nitrotyrosine staining), eNOS uncoupling and endothelial dysfunction. Importantly, the expression of the phagocytic NADPH oxidase isoform (NOX-2) was down-regulated by exercise in control mice, whereas it was up-regulated in exercising α1AMPKflox/flox x TekCre+ animals. In addition, nitric oxide bioavailability was decreased and the antioxidant/protective nuclear factor erythroid 2-related factor 2 (Nrf-2) response via heme oxygenase 1 and uncoupling protein-2 (UCP-2) was impaired in exercising α1AMPKflox/flox x TekCre+ mice. Our results demonstrate that endothelial α1AMPK is a critical component of the signaling events that enable vascular protection in response to exercise. Moreover, they identify endothelial α1AMPK as a master switch that determines whether the effects of exercise on the vasculature are protective or detrimental.
Jansen et al. (Fri,) conducted a other in Endothelial dysfunction. Voluntary exercise training vs. Wild-type mice undergoing voluntary exercise training was evaluated on Endothelial function, reactive oxygen species production, and eNOS uncoupling. Voluntary exercise training caused deleterious effects, including elevated reactive oxygen species production and eNOS uncoupling, in mice lacking endothelial α1AMPK compared to wild-type mice.