Cyclovirobuxine D ameliorates cardiac hypertrophy by enhancing mitochondrial function via miR-30b-5p/ALCAT1 Pathway

It is well known that cardiac hypertrophy has been reported as an independent risk factor for cardiac dysfunction and heart failure involving in mitochondrial dysfunction. Cyclovirobuxine D (CVB-D), as a natural alkaloid extracted from the traditional Chinese herb Buxus sinica, has demonstrated therapeutic effects in ameliorating cardiac hypertrophy and mitochondrial dysfunction. However, the related mechanism remains to be investigated in depth.

At present, the protection properties and mechanism of CVB-D is to be investigated on mitochondrial dysfunction in cardiomyocytes of during cardiac hypertrophy.

The model of cardiac hypertrophy was reproduced in C57BL / 6 mice by treated with the subcutaneous injection of aldosterone (Ald) and high salt water. The primary rat cardiomyocytes (NRCMs) and mouse cardiac muscle cell (HL-1) lines were exposed to Ald for cardiomyocytes hypertrophy. Blood samples of patients with heart failure were obtained. The pharmacological properties of CVB-D and its mechanism in mitochondrial dysfunction and cardiac hypertrophy progression were investigated in the successful models with miRNA-seq, bioinformatics analysis, the dual-luciferase reporter assay, miR-30b-5p agonist/inhibitor, and genetic interventions in vivo and in vitro.

CVB-D attenuated Ald-induced cardiac hypertrophy, as evidenced by a decreased heart weight-to-body weight ratio, improved myocardial fibrosis and cardiac function, inhibited cardiomyocyte hypertrophy, and relieved mitochondrial fusion and fission abnormalities. In cardiomyocytes, adenovirus-mediated ALCAT1 overexpression exacerbated Ald-induced cardiomyocyte hypertrophy and mitochondrial dysfunction, and weakened the protective effect of CVB-D against cardiac hypertrophy. ALCAT1 knockdown significantly repressed Ald-induced cardiac dysfunction, cardiomyocyte hypertrophy, and mitochondrial dysfunction in vivo and in vitro. Furthermore, ALCAT1 was identified as a downstream target gene of miR-30b-5p miR-30b-5p mimics transfection could suppress Ald-induced mitochondrial dysfunction and cardiac hypertrophy progression, whereas miR-30b-5p inhibitor exerted opposite effects and abolished the protective effect of CVB-D. In vivo validation via tail vein injection of miR-30b-5p agomir or antagomir into mice yielded results consistent with in vitro experiments.

our findings demonstrate for the first time that the miR-30b-5p/ALCAT1 pathway is a novel regulator of mitochondrial dysfunction in the progression of cardiac hypertrophy. CVB-D ameliorates Ald-induced cardiac hypertrophy by protecting mitochondrial function via the miR-30b-5p/ALCAT1 pathway.