Identification of miRNAs Expression Characteristics and Biomarkers in Serum-Derived Exosomes of Wilson's Disease Patients.

Background: Wilson's disease (WD), caused by mutations in the ATP7B gene, leads to copper accumulation and multi-organ damage. Exosomal microRNAs (miRNAs) play a crucial role in cell-to-cell communication and the pathogenesis of diseases, yet their study in WD remains unreported. This study aims to characterize the serum exosomal miRNA signature in WD patients and investigate its potential as a source of biomarkers and therapeutic targets. Methods: Serum exosomes from WD patients and healthy controls were isolated for RNA sequencing to identify differentially expressed miRNAs (DE-miRNAs). An integrated bioinformatics approach was employed, encompassing Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, and Disease Ontology (DO) analyses to systematically decipher the functional roles, pathway involvements, and disease associations of the DE-miRNAs. Selected DE-miRNAs were validated by RT-qPCR. Results: We identified 59 DE-miRNAs (23 upregulated, 34 downregulated) in WD patient serum exosomes. GO analysis revealed their significant involvement in signal transduction, metal ion binding, and metabolic pathways. KEGG analysis highlighted alterations in key signaling cascades, including Ras, PI3K-Akt, and Hippo pathways. Reactome analysis further uncovered disruptions in specific biological modules, notably ubiquitin-mediated proteolysis, GPCR signaling, and spliceosome assembly. DO enrichment demonstrated significant associations with hepatocellular carcinoma, neuropsychiatric disorders, and metabolic diseases. RT-qPCR validation confirmed the reliability of DE-miRNA expression patterns (p  < 0.05). Conclusions: This study establishes the first comprehensive landscape of serum exosomal miRNAs in WD, revealing their involvement in an interconnected network of pathological processes. Our findings provide a novel conceptual framework for understanding WD pathophysiology and pinpoint promising candidates for biomarker development.