Integrated Bioinformatic and Experimental Identification of DHCR24 and NRG1 as Key Cellular Aging Genes in Diabetic Cardiomyopathy

PURPOSE: Cell aging (CA) is increasingly recognized as a determinant in the pathogenesis of diabetic cardiomyopathy (DCM), yet the molecular mechanisms underlying this process remain unclear. This study aimed to identify aging-associated targets in diabetic cardiac cells and analyze alterations in intercellular ligand-receptor communication. METHODS: Integrative bioinformatic analysis and single-cell transcriptomics were employed. Differentially expressed genes (DEGs) were extracted from a DCM-related dataset and intersected with 543 aging-associated genes, yielding five candidate genes (NRG1, IGFBP5, IL6, DHCR24, and CDKN1A). These candidates were further screened through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Subsequent validation involved TF-mRNA-miRNA network construction. The expression and functional roles of the final key genes were investigated using both in vivo (DCM mouse model) and in vitro (myocardial microvascular endothelial cells) models. RESULTS: Exploratory single-cell transcriptomic profiling suggested NRG1 upregulation in monocytes from the DCM sample, while DHCR24 showed a trend of enrichment in endothelial cells in the single DCM sample analyzed. These preliminary observations, derived from a limited sample without biological replicates, serve to generate hypotheses regarding cell type-specific expression patterns that warrant validation in independent cohorts. In monocytes from DCM samples, while DHCR24 was primarily enriched in endothelial cells of the DCM group. In DCM mouse hearts, qRT-PCR and Western blot analyses confirmed that DHCR24 mRNA and protein levels were significantly downregulated (by approximately 2.89-fold and 1.82-fold, respectively), whereas NRG1 showed an upward trend. In vitro, silencing DHCR24 with siRNA in myocardial microvascular endothelial cells under high-glucose/high-lipid stress significantly reduced cell viability (eg, by 50% in CCK-8 assay) and exacerbated cellular aging phenotypes, including increased senescence-associated β-galactosidase (SA-β-Gal) activity and elevated expression of p21/p16, confirming its protective functional role in DCM pathogenesis. CONCLUSION: DHCR24 contributes to the fundamental molecular mechanisms driving DCM and represents a potential therapeutic target for diabetes-related cardiac microvascular injury. These findings, derived from a comprehensive approach spanning bioinformatics to in vivo and in vitro validation, provide robust experimental evidence advancing the understanding of DCM pathogenesis.