Fibroblast-Restricted Inflammasome Activation Promotes Atrial Fibrillation and Heart Failure With Diastolic Dysfunction.

Atrial fibrillation (AF) often coexists with heart failure, both involving inflammatory signaling and cardiac fibroblasts. To understand the role of fibroblast NLR family pyrin domain containing 3 (NLRP3) inflammasome in cardiac function, we found that NLRP3 was up-regulated in atrial fibroblasts from AF patients. Fibroblast-specific activation of NLRP3 in mice induced AF-promoting atrial myopathy and heart failure with diastolic dysfunction, accompanied by increased fibrosis, and reduced conduction velocity. Knockdown of NLRP3 prevented the AF-promoting atrial substrate and cardiomyopathy in the context of NLRP3 activation in fibroblasts. We identify the fibroblast NLRP3 inflammasome as a key pathway governing the promotion of proarrhythmic fibrosis in AF and cardiomyopathy.