Interferon regulatory factor 7 functions as a novel negative regulator of pathological cardiac hypertrophy.

ABSTRACT: Cardiac hypertrophy is a complex pathological process that involves multiple factors including inflammation and apoptosis. Interferon regulatory factor 7 (IRF7) is a multifunctional regulator that participates in immune regulation, cell differentiation, apoptosis, and oncogenesis. However, the role of IRF7 in cardiac hypertrophy remains unclear. We performed aortic banding in cardiac-specific IRF7 transgenic mice, IRF7 knockout mice, and the wild-type littermates of these mice. Our results demonstrated that IRF7 was downregulated in aortic banding-induced animal hearts and cardiomyocytes that had been treated with angiotensin II or phenylephrine for 48 hours. Accordingly, heart-specific overexpression of IRF7 significantly attenuated pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of IRF7 led to opposite effects. Moreover, IRF7 protected against angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, we identified that IRF7-dependent cardioprotection was mediated through IRF7 binding to inhibitor of ?B kinase-?, and subsequent nuclear factor-?B inactivation. In fact, blocking nuclear factor-?B signaling with cardiac-specific inhibitors of ?B?(S32A/S36A) super-repressor transgene counteracted the adverse effect of IRF7 deficiency. Conversely, activation of nuclear factor-?B signaling via a cardiac-specific conditional inhibitor of ?B kinase-?(S177E/S181E) (constitutively active) transgene negated the antihypertrophic effect of IRF7 overexpression. Our data demonstrate that IRF7 acts as a novel negative regulator of pathological cardiac hypertrophy by inhibiting nuclear factor-?B signaling and may constitute a potential therapeutic target for pathological cardiac hypertrophy.

SUBMITTER: Jiang DS 

PROVIDER: S-EPMC5349187 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature