Abstract
OBJECTIVES: To investigate whether ophiopogonin D (OD) alleviates doxorubicin (Dox)‑induced myocardial hypertrophy in mice by regulating the β‑catenin/FUNDC1/mitophagy signaling axis. METHODS: Thirty C57BL/6J mice were randomized equally into control group, Dox treatment group, Dox with OD treatment group, Dox treatment group with injection of adeno-associated virus (AAV) vector carrying β‑catenin, and Dox treatment group with injection of AAV vector. RNA sequencing analysis was used to identify differentially expressed genes in cultured mouse cardiac cells following Dox treatment. Western blotting was performed to examine the protein levels of β‑catenin, active β‑catenin, FUNDC1, LC3, p62, β‑myosin heavy chain (β-MHC), and α‑actin; immunohistochemistry and immunofluorescence staining were used to assess the localization and expression of β-catenin and FUNDC1. Transmission electron microscopy was employed to evaluate mitochondrial damage in the cardiac myocytes. Chromatin immunoprecipitation and dual-luciferase reporter gene assays were used to investigate the transcriptional regulation of FUNDC1 by β‑catenin. RESULTS: Dox treatment significantly inhibited β‑catenin signaling and FUNDC1-mediated mitophagy, leading to cardiomyocyte hypertrophy and mitochondrial damage. OD treatment obviously reversed these effects, restored β‑catenin signaling, enhanced FUNDC1 transcription and expression, and promoted mitophagy. Overexpression of β‑catenin or FUNDC1 mimicked the cardioprotective effect of OD, while knockdown of β‑catenin aggravated myocardial hypertrophy, which was reversed by FUNDC1 overexpression. Mechanistically, β‑catenin directly bound to the FUNDC1 promoter and activated its transcription. CONCLUSIONS: OD alleviates Dox-induced myocardial hypertrophy in mice by activating the β‑catenin/FUNDC1/mitophagy axis and enhancing mitochondrial quality control.