Identifying the Oxidative Stress-related Hub Genes in Dilated Cardiomyopathy by Bioinformatics Analysis

Introduction: Characterized as an idiopathic primary myocardial disorder, dilated cardiomyopathy (DCM) predominantly affects children and elderly adults. However, a lack of specific clinical symptoms and reliable biomarkers impedes timely diagnosis and rational clinical management of DCM. Methods: Whole-genome expression profiles (GSE120895, GSE9800) were retrieved from the Gene Expression Omnibus database via the GEOquery R package. A series of bioinformatic methods were employed, including DEG, GSVA, WGCNA, GO/KEGG enrichment, PPI, and immune infiltration analysis. Key biomarkers were validated by qRT-PCR in a Doxorubicin (DOX)-induced DCM model. Results: In total, 629 differentially expressed genes (DEGs) were screened out between DCM and control groups. Combined analysis of DEGs and WGCNA outputs identified 13 hub genes overlapping with oxidative stress-associated gene modules. Receiver Operating Characteristic (ROC) curve analyses confirmed that these hub genes exhibit favorable diagnostic efficiency for DCM. Functional enrichment results showed that these genes are mainly enriched in transmembrane transport and nucleotide metabolism pathways. Immune infiltration analysis indicated significantly elevated infiltration levels of five immune cell subsets in DCM myocardial tissues. In vivo experiments verified the significant upregulation of five core hub genes in DOX-induced DCM mice. By screening hub genes with diagnostic potency based on public transcriptome datasets and validating their expression alterations in a DOX-induced DCM animal model, this study provides partial experimental evidence to support the above bioinformatic outcomes. discussion: DCM is a heterogeneous cardiomyopathy characterized by ventricular enlargement and reduced myocardial contractile function[43,44]. Due to the lack of early diagnostic indicators, patients with DCM often lose the best opportunity for treatment, resulting in a poor prognosis. Oxidative stress is a critical factor in the development of DCM[45–47]. It significantly influences the progression of heart damage and remodeling by triggering the expression of numerous genes[48]. Therefore, analyzing and identifying the oxidative stress-related biomarkers has significant implications for improving prognosis for DCM patients[49,50]. In this study, 13 oxidative stress-related DEGs were identified by the intersection of WGCNA module genes and DEGs, which laid a foundation for subsequent mechanism studies. Further validation in a mouse DCM model confirmed the potential value of MVP, WISP1, FCN1, AMPD3, RARRES1, FTL, KRT14, these hub genes as biomarkers. Based on the expression of PCR and pathway enrichment, MVP, WISP1, FTL, and FCN1 genes were selected as the focus of in-depth study. MVP(Major Vault Protein) is the main component of cellular ribonucleoprotein particles located in the cytoplasm[51]. MVP is known to regulate several cellular processes including nucleocytoplasmic transport, signal transduction, cellular differentiation, cell survival, and immune responses[52]. MVP in macrophages specifically can promote SR-A-mediated TNF-α synthesis and apoptosis[53], and it can also prevent metabolic diseases via NF-κB signaling[54]. In this study, MVP performance showed its value as a potential biomarker. The ROC curve analysis showed that MVP had an AUC value of 0.812, indicating that MVP had a good ability to distinguish between patients with DCM and healthy controls, suggesting that MVP may play an important role in the early diagnosis of DCM. Further analysis showed that MVP expression was closely related to the infiltration of specific immune cells, especially with CD56dim natural killer cells (correlation coefficient R=0.683, p