Small-molecule 7,8-dihydroxyflavone counteracts compensated and decompensated cardiac hypertrophy via AMPK activation

BACKGROUND Pathological cardiac hypertrophy is a compensated response to various stimuli and is considered a key risk factor for heart failure. 7,8-Dihydroxyflavone (7,8-DHF) is a flavonoid derivative that acts as a small-molecule brain-derived neurotrophic factor mimetic. The present study aimed to explore the potential role of 7,8-DHF in cardiac hypertrophy. METHODS Kunming mice and H9c2 cells were exposed to transverse aortic constriction or isoproterenol (ISO) with or without 7,8-DHF, respectively. F-actin staining was performed to calculate the cell area. Transcriptional levels of hypertrophic markers, including ANP, BNP, and beta-MHC, were detected. Echocardiography, hematoxylin-eosin staining, and transmission electron microscopy were used to examine the cardiac function, histology, and ultrastructure of ventricles. Protein levels of mitochondria-related factors, such as adenosine monophosphate-activated protein kinase (AMPK), and peroxisome proliterator-activated receptor gamma coactivator-1 alpha (PGC-1 alpha), were detected. RESULTS 7,8-DHF inhibited compensated and decompensated cardiac hypertrophy, diminished the cross-sectional area, and alleviated the mitochondrial disorders of cardiomyocytes. Meanwhile, 7,8-DHF reduced the cell size and repressed the mRNA levels of the hypertrophic markers of ISO-treated cardiomyocytes. In addition, 7,8-DHF activated AMPK and PGC-1 alpha signals without affecting the protein levels of mitochondrial dynamics-related molecules. The effects of 7,8-DHF were eliminanted by Compound C, an AMPK inhibitor. CONCLUSIONS These findings suggest that 7,8-DHF inhibited cardiac hypertrophy and mitochondrial dysfunction by activating AMPK signaling, providing a potential agent for the treatment of pathological cardiac hypertrophy.

Automated summary

This study found that 7,8-DHF can inhibit cardiac hypertrophy and mitochondrial dysfunction by activating the AMPK signaling pathway, providing a potential agent for the treatment of pathological cardiac hypertrophy.