Xin-Ji-Er-Kang alleviates chronic heart failure by suppressing mtDNA/cGAS-STING signaling through NR3C1-mediated MFN2 upregulation.

Abstract

BACKGROUND: cGAS/STING signaling activation driven by mitochondrial DNA (mtDNA) release contributes to chronic heart failure (CHF) pathogenesis. Although the traditional Chinese medicine Xin-Ji-Er-Kang (XJEK) shows cardioprotective potential, its regulation of mtDNA dynamics remains unclear. PURPOSE: To elucidate how XJEK inhibits mtDNA/cGAS/STING-driven inflammation and improves CHF. METHODS: Murine myocardial ischemia-reperfusion (MIR) injury models and cardiomyocyte hypoxia/reoxygenation (H/R) models were used to evaluate the cardioprotective effects of XJEK in vivo and in vitro. High-throughput sequencing identified potential therapeutic targets of XJEK. Network pharmacology and bioinformatic analyses were then applied for target prediction and pathway enrichment. Integrated experimental approaches including RT-qPCR, immunofluorescence, immunoblotting, dual-luciferase reporter assays, and ChIP-qPCR were implemented to elucidate XJEK-mediated regulatory mechanisms governing cGAS/STING signaling in both models. RESULTS: XJEK treatment significantly ameliorated myocardial fibrosis and attenuated ventricular remodeling in mice with MIR-induced heart failure. High-throughput sequencing identified mitofusin 2 (MFN2) as a key regulator mediating XJEK's cardioprotective effects. XJEK rescued MIR- and H/R-induced downregulation of MFN2, thereby suppressing mtDNA release and the consequent excessive activation of the cGAS/STING signaling and downstream inflammatory responses. Furthermore, integrated network pharmacology and bioinformatic analyses revealed nuclear receptor subfamily 3 group C member 1 (NR3C1) as the transcription factor promoting MFN2 expression. Mechanistically, XJEK facilitated the nuclear translocation of NR3C1, enabling this process. CONCLUSION: XJEK attenuates CHF progression by facilitating NR3C1 nuclear translocation, enhancing its binding to the MFN2 promoter to upregulate transcription and expression, thereby suppressing mtDNA/cGAS/STING signaling activation and inflammatory responses.