Abstract P3091: Suppression Of Myeloid Yap Antagonizes Adverse Cardiac Remodeling During Pressure Overload Stress

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Inflammation is an integral component of cardiovascular disease and is thought to contribute to cardiac dysfunction and heart failure. While ischemia-induced inflammation has been extensively studied in the heart, relatively less is known regarding cardiac inflammation during non-ischemic stress. Recent work has implicated a role for Yes-associated protein (YAP) in modulating inflammation in response to ischemic injury; however, whether YAP influences inflammation in the heart during non-ischemic stress is not described. We hypothesized that YAP mediates a pro-inflammatory response during pressure overload (PO)-induced non-ischemic injury, and that targeted YAP inhibition in the myeloid compartment is cardioprotective. In mice, PO elicited myeloid YAP activation, and myeloid-specific YAP knockout mice (YAP F/F ;LysM Cre ) subjected to PO stress had preserved systolic function, and attenuated pathological remodeling compared to control mice. Inflammatory indicators were also significantly attenuated, while pro-resolving genes including Vegfa were enhanced, in the myocardium of myeloid YAP KO mice after PO. Experiments using bone marrow-derived macrophages (BMDMs) from YAP KO and control mice demonstrated that YAP suppression shifted polarization toward a resolving phenotype. We also observed attenuated NLRP3 inflammasome priming and function in YAP deficient BMDMs, as well as in myeloid YAP KO hearts following PO, indicating disruption of inflammasome induction. Studies in RAW264.7 cells demonstrated the effectiveness of pharmacological YAP inhibition using verteporfin to attenuate pro-inflammatory gene expression, and augment VEGFA levels. Finally, we leveraged nanoparticle-mediated delivery of verteporfin and observed attenuated PO-induced pathological remodeling and inflammation compared to DMSO nanoparticle control treatment. These data implicate myeloid YAP as an important molecular nodal point that facilitates cardiac inflammation and fibrosis during PO stress and suggest that selective inhibition of YAP may prove a novel therapeutic target in non-ischemic heart disease.