(849.21) Activating P2Y1 receptors improves function in arteries with repressed autophagy

Poster Board Number: E21

Jae Min Cho (University of Utah), Seul-Ki Park (University of Utah), Oh Sung Kwon (University of Connecticut), D. La Salle (University of Utah), James Cerbie (University of Utah), Caitlin Fermoyle (University of Utah), David Morgan (University of Utah), Ashley Nelson (George E. Whalen Veterans Affairs Medical Center), Amber Bledsoe (University of Utah), Leena Bharath (University of Utah), Megan Tandar (University of Utah), Satya Kunapuli (Temple University), Russell Richardson (University of Utah), Pon Velayutham Anandh Babu (University of Utah), Sohom Mookherjee (University of Utah), Bellamkonda Kishore (University of Utah), Fei Wang (University of Utah), Tianxin Yang (University of Utah), Sihem Boudina (University of Utah), Joel Trinity (University of Utah), J. Symons (University of Utah)

Objective and hypothesis. The importance of endothelial cell (EC) autophagy to vascular homeostasis in the context of health and disease is evolving. Earlier we reported that intact EC autophagy is requisite to maintain shear-stress-induced nitric oxide (NO) generation via glycolysis-dependent purinergic signaling to eNOS. Here we illustrate the translational and functional significance of these findings. Methods and Results. First, we assessed translational relevance using older male humans and mice that exhibit blunted EC autophagy and impaired arterial function vs. adult controls. Active hyperemia evoked by rhythmic handgrip exercise elevated radial artery shear rate similarly from baseline in adult (23±1 y) and older (68±2 y) subjects for 60-min. Compared to baseline, indexes of autophagy initiation, p-eNOSS1177 activation, and NO generation, occurred in radial artery ECs obtained from adult but not older volunteers. Regarding mice, indexes of autophagy and p-eNOSS1177 activation were robust in ECs from adult (7 ± 1 months) but not older (23 ± 1 months) animals that completed 60-min treadmill-running. Further, results concerning the extracellular acidification rate (ECAR; Seahorse Bioanalyzer) indicate glycolysis and glycolytic capacity were elevated in response to 20 dyn/cm2 laminar shear stress x 45-min in primary arterial ECs obtained from adult but not older mice. We next questioned whether the inability to initiate EC autophagy, glycolysis, and p-eNOSS1177 precipitates dysfunction in arteries from older vs. adult mice. Compromised intraluminal flow-mediated vasodilation displayed by arteries from older vs. adult mice was recapitulated in vessels from adult mice by: (i) NO synthase inhibition; (ii) acute autophagy impairment using 3-methyladenine (3-MA); (iii) EC Atg3 depletion (Atg3EC-/- mice); (iv) purinergic 2Y1-receptor (P2Y1-R) blockade; and (v) germline depletion of P2Y1-Rs. Importantly, P2Y1-R activation using 2-methylthio-ADP (2-Me-ADP) improved vasodilatory capacity in arteries from: (i) adult mice treated with 3-MA; (ii) adult Atg3EC-/- mice; and (iii) older animals with repressed EC autophagy. Conclusions. Arterial dysfunction concurrent with pharmacological, genetic, and age-associated EC autophagy disruption is improved by activating P2Y1-Rs.

Jae Min Cho: AHA Predoctoral Fellowship: 20PRE35110066, UU Graduate Research Fellowship
Seul-Ki Park: AHA Postdoctoral Fellowship, 17POST33670663
J David Symons: RO1: NIHRO1HL141540, AHA16GRNT31050004, NIH RO3AGO52848