Pristimerin protects against pathological cardiac hypertrophy through improvement of PPARα pathway

Pristimerin (PM), serving as a biological component mainly obtained from Celastraceae and Hippocrateaceae families, has been extensively explored for its numerous pharmacological activities, especially anti-cancer activity. However, the function of PM on pathological cardiac hypertrophy is poorly understood. This work was intended to investigate the effects of PM on pressure-overload induced myocardial hypertrophy and its potential pathways. Mouse model of pathological cardiac hypertrophy was generated by transverse aortic constriction (TAC) or minipump administration of the β-adrenergic agonist ISO for 4 weeks, and PM (0.5 mg/Kg/d, i.p.) was treated for 2 weeks. PPARα-/- mice received TAC surgery were used for mechanism exploration. Moreover, neonatal rat cardiomyocytes (NRCMs) were utilized to explore the effect of PM following Angiotensin II (Ang II, 1.0 μM) administration. We found that PM attenuated pressure-overload induced cardiac dysfunction, myocardial hypertrophy and fibrosis in mice. Likewise, PM incubation dramatically reversed Ang II-mediated cardiomyocytes hypertrophy in NRCMs. RNA-Sequence showed that PM selectively contributed to improvement of PPARα/PGC1 signaling, while silencing PPARα abrogated the beneficial effects of PM on Ang II-treated NRCMs. Importantly, PM ameliorated Ang II-induced mitochondrial dysfunction and decrease in metabolic genes, whereas knockdown of PPARα eliminated these alterations in NRCMs. Similarly, PM presented limited protective effects on pressure-overload induced systolic dysfunction and myocardial hypertrophy in PPARα deficient mice. Overall, this study revealed that PM exerted protective activity against pathological cardiac hypertrophy through improvement of PPARα/PGC1 pathway.