Background: Doxorubicin (DOX) is an effective broad-spectrum antitumor drug, but its clinical application is limited due to the side effects of cardiac damage. Astragaloside IV (AS-IV) is a significant active component of Astragalus membranaceus that exerts cardioprotective effects through various pathways. However, whether AS-IV exerts protective effects against DOX-induced myocardial injury by regulating the pyroptosis is still unknown and is investigated in this study. Methods: The myocardial injury model was constructed by intraperitoneal injection of DOX, and AS-IV was administered via oral gavage to explore its specific protective mechanism. Cardiac function and cardiac injury indicators, including lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase isoenzyme (CK-MB), and brain natriuretic peptide (BNP), and histopathology of the cardiomyocytes were assessed 4 weeks post DOX challenge. Serum levels of IL-1β, IL-18, superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH) and the expression of pyroptosis and signaling proteins were also determined. Results: Cardiac dysfunction was observed after the DOX challenge, as evidenced by reduced ejection fraction, increased myocardial fibrosis, and increased BNP, LDH, cTnI, and CK-MB levels (p < 0.05, N = 3–10). AS-IV attenuated DOX-induced myocardial injury. The mitochondrial morphology and structure were also significantly damaged after DOX treatment, and these changes were restored after AS-IV treatment. DOX induced an increase in the serum levels of IL-1β, IL-18, SOD, MDA and GSH as well as an increase in the expression of pyroptosis-related proteins (p < 0.05, N = 3–6). Besides, AS-IV depressed myocardial inflammatory-related pyroptosis via activation of the expressions of nuclear factor E2-related factor 2 (Nrf-2) and heme oxygenase 1 (HO-1) (p < 0.05, N = 3). Conclusions: Our results showed that AS-IV had a significant protective effect against DOX-induced myocardial injury, which may be associated with the activation of Nrf-2/HO-1 to inhibit pyroptosis.

Chronic alcohol intake contributes to high mortality rates due to ethanol-induced cardiac hypertrophy and contractile dysfunction, which are accompanied by increased oxidative stress and disrupted mitophagy. Alpha-lipoic acid (α-LA), a well-known antioxidant, has been shown to protect against cardiac hypertrophy and inflammation. However, little is known about its role and mechanism in the treatment of alcoholic cardiomyopathy. Here, we evaluated the role of α-LA in alcohol-induced cardiac damage by feeding mice a 4.8% (v/v) alcohol diet with or without α-LA for 6 w. Our results suggested that chronic alcohol consumption increased mortality, blood alcohol concentrations, and serum aldehyde levels, but a-LA attenuated the elevations in mortality and aldehydes. Chronic alcohol intake also induced cardiac dysfunction, including enlarged left ventricles, reduced left ventricular ejection fraction, enhanced cardiomyocyte size, and increased serum levels of brain natriuretic peptide, lactate dehydrogenase, and creatine kinase myocardial isoenzyme. Moreover, alcohol intake led to the accumulation of collagen fiber and mitochondrial dysfunction, the effects of which were alleviated by α-LA. In addition, α-LA intake also prevented the increase in reactive oxygen species production and the decrease in mitochondrial number that were observed after alcohol consumption. Chronic alcohol exposure activated PINK1/Parkin-mediated mitophagy. These effects were diminished by α-LA intake by the activation of aldehyde dehydrogenase 2. Our data indicated that α-LA helps protect cardiac cells against the effects of chronic alcohol intake, likely by inhibiting PINK1/Parkin-related mitophagy through the activation of aldehyde dehydrogenase 2.

This study aimed to investigate liraglutide's protective effects against doxorubicin (DOX)-induced cardiotoxicity and ferroptosis, and to elucidate the underlying mechanisms involving signal transducer and activator of transcription 3 (STAT3) signaling and its post-translational palmitoylation. In vivo models of chronic DOX-induced cardiotoxicity were established in male C57BL/6 J mice. Cardiac function was assessed via echocardiography. Ferroptosis markers such as malondialdehyde (MDA), glutathione (GSH), iron (Fe²⁺), reactive oxygen species (ROS), mitochondrial ultrastructure) were evaluated in myocardial tissue and H9c2 cardiomyocytes. Bioinformatics analysis of the GSE193861 dataset identified ferroptosis-related differentially expressed genes. STAT3 and DHHC7 were modulated using short hairpin RNA (shRNA) knockdown and cardiomyocyte-specific adeno-associated virus 9 (AAV9)-mediated overexpression. Molecular interactions were assessed via co-immunoprecipitation, acyl-biotin exchange assays, and western blotting. Liraglutide administration significantly attenuated DOX-induced cardiac dysfunction and cardiomyocyte ferroptosis. Bioinformatics identified STAT3 as a central regulator, with liraglutide restoring DOX-impaired STAT3 phosphorylation and nuclear translocation, thereby enhancing transcription of the anti-ferroptotic enzyme glutathione peroxidase 4 (GPX4). STAT3 knockdown abolished liraglutide's protection. Mechanistically, liraglutide upregulated the palmitoyltransferase DHHC7, rescuing DOX-suppressed STAT3 palmitoylation. DHHC7 knockdown and palmitoylation inhibition abrogated liraglutide-mediated STAT3 phosphorylation and anti-ferroptotic effects. Crucially, cardiomyocyte-specific DHHC7 overexpression replicated liraglutide's cardioprotection, mitigating DOX-induced ferroptosis and dysfunction. We demonstrate a novel cardioprotective axis wherein liraglutide enhances DHHC7-dependent STAT3 palmitoylation, facilitating its phosphorylation, nuclear translocation, and transcriptional activation of GPX4 to suppress ferroptosis. This study provides the first evidence that DHHC7-mediated STAT3 palmitoylation is essential for liraglutide's efficacy, identifying a promising therapeutic target for DOX cardiotoxicity.

Circular noncoding RNAs (circRNAs) are implicated in many human diseases, but their role in atrial fibrillation (AF) is poorly understood. In this study, we performed bioinformatics analysis of circRNA sequencing data to identify AF-related circRNAs. Left atrial appendage (LAA) samples were obtained from patients with valvular heart disease and were categorised into the sinus rhythm (SR; n = 4) and AF (n = 4) groups. CircRNA sequencing analysis was performed to identify differentially expressed (DE) circRNAs in AF patients. Functional enrichment analysis of DE circRNAs was performed to identify enriched Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We identified 3338 DE circRNAs, including 2147 upregulated and 1191 downregulated circRNAs, in AF patients. A ceRNA network of 16 DE circRNAs, 11 DE miRNAs, and 15 DE mRNAs was constructed. Functional enrichment analyses revealed that the AF-related DE circRNAs were enriched in response to vitamin D, the potassium channel complex, delayed rectifier potassium channel activity, osteoclast differentiation, primary immunodeficiency, endocrine and other factor-regulated calcium reabsorption and other processes. ROC curve analysis identified circRNA_00324, circRNA_17225, circRNA_16305, circRNA_10233, circRNA_05499, circRNA_03183, circRNA_14211, and circRNA_18422 as potential predictive biomarkers for distinguishing AF patients from SR patients, with AUC values of 0.9138, 0.7370, 0.8526, 0.6803, 0.8163, 0.8662, 0.7664, and 0.9320, respectively. In this study, we constructed an AF-related ceRNA network and identified eight circRNAs as potential predictive biomarkers of AF.