Rosmarinic acid attenuates cardiac fibrosis following long-term pressure overload via AMPK?/Smad3 signaling.
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ABSTRACT: Agonists of peroxisome proliferator-activated receptor gamma (PPAR-?) can activate 5' AMP-activated protein kinase alpha (AMPK?) and exert cardioprotective effects. A previous study has demonstrated that rosmarinic acid (RA) can activate PPAR-?, but its effect on cardiac remodeling remains largely unknown. Our study aimed to investigate the effect of RA on cardiac remodeling and to clarify the underlying mechanism. Mice were subjected to aortic banding to generate pressure overload induced cardiac remodeling and then were orally administered RA (100?mg/kg/day) for 7 weeks beginning 1 week after surgery. The morphological examination, echocardiography, and molecular markers were used to evaluate the effects of RA. To ascertain whether the beneficial effect of RA on cardiac fibrosis was mediated by AMPK?, AMPK?2 knockout mice were used. Neonatal rat cardiomyocytes and fibroblasts were separated and cultured to validate the protective effect of RA in vitro. RA-treated mice exhibited a similar hypertrophic response as mice without RA treatment, but had an attenuated fibrotic response and improved cardiac function after pressure overload. Activated AMPK? was essential for the anti-fibrotic effect of RA via inhibiting the phosphorylation and nuclear translocation of Smad3 in vivo and in vitro, and AMPK? deficiency abolished RA-mediated protective effects. Small interfering RNA against Ppar-? (siPpar-?) and GW9662, a specific antagonist of PPAR-?, abolished RA-mediated AMPK? phosphorylation and alleviation of fibrotic response in vitro. RA attenuated cardiac fibrosis following long-term pressure overload via AMPK?/Smad3 signaling and PPAR-? was required for the activation of AMPK?. RA might be a promising therapeutic agent against cardiac fibrosis.
SUBMITTER: Zhang X
PROVIDER: S-EPMC5833382 | biostudies-literature | 2018 Jan
REPOSITORIES: biostudies-literature
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