Presentation description

With the prevalence of cardiovascular disease (CVD) increasing world wide and the precise mechanisms responsible for CVD remaining elusive, the need for novel therapeutic interventions is urgent. Autophagy is a conserved process whereby damaged and dysregulated intracellular proteins are identified, tethered, and escorted to the lysosome for degradation and recycling. Emerging evidence indicates that autophagy is important in maintaining endothelial cell (EC) proteostasis and function. My laboratory showed that: (i) autophagy repression specifically in adult mice ECs produces arterial dysfunction; and (ii) indexes of autophagy are repressed in ECs of older mice and humans that display concurrent EC dysfunction. Sequestosome 1 (p62) tethers proteins targeted for degradation and enables their entry into the autophagic pathway. The contribution from EC p62 to cardiovascular and metabolic function is unknown and experiments are needed to investigate this. Thus, p62 will be depleted from ECs of adult male and female mice (KO) via tamoxifen regimen, and results will be compared to animals wherein EC p62 is intact (CON). The efficacy and specificity of EC p62 depletion will be evaluated in both groups by measuring p62k mRNA (qPCR) and protein (immunoblotting) expression in ECs and vascular smooth muscle. Three adjacent 1 mm thoracic aorta sections will be obtained 14 days after the tamoxifen regimen. The center aorta section will be used to measure intrinsic mechanical stiffness by wire myography, with the other two used to find lumen diameter and intimal medial thickness. The aortic ring diameter will be increased incrementally by 50 µM every 3 minutes until failure. The elastic modulus will be estimated from the stress vs strain curve, lumen diameter, and intimal medial thickness and then compared between the groups to show the differences caused by p62 deletion. We expect p62 deletion from ECs to increase intrinsic aortic stiffness.|This project is supported by: NIH RO1 HL141540 (JDS); AHA23PRE1025910 (SM); and the|RUUTE (CG) and PIRIP (LG) Summer Research Programs.