Involvement of pyroptosis pathway in epicardial adipose tissue - myocardium axis in experimental heart failure with preserved ejection fraction.

Epicardial adipose tissue (EAT) is a metabolically active organ which generates inflammatory cytokines. Thickness of EAT is associated with onset and development of heart failure with preserved ejection fraction (HFpEF). However, it is still unclear the specific mechanisms and pharmacological targets on EAT induced inflammation in HFpEF. A two-hit protocol with western diet and Nω-nitrol-arginine methyl ester (L-NAME) was used to establish HFpEF mouse model. In HFpEF mice, inflammatory biomarkers, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and von willebrand factor (vWF) elevated in myocardium compared to control. Inflammatory cell infiltration in myocardium was increased. In HFpEF mice, inflammasome-mediated pyroptosis pathway was activated in the EAT. Suppression of pyroptosis-related protein gasdermin D (GSDMD) in cultured EAT could lower cardiomyocyte inflammation and autophagy. Furthermore, spironolactone and rosuvastatin, the two-hit anti-inflammatory agents, reduced NLR family pyrin domain containing 3 (NLRP3)/GSDMD pyroptosis in EAT and autophagy in myocardium of HFpEF mouse. The combination treatment also enhanced exercise tolerance and appeased inflammatory injuries in HFpEF mice. CONCLUSION: Pyroptosis signaling is involved in EAT-myocardium axis in mouse model of HFpEF. Targeting adipocyte-derived inflammation in EAT bears potential to treatment HFpEF.