Integrative In Silico Analysis of miRNA–mRNA Regulatory Networks in the Prefrontal Cortex of Individuals with Psychiatric Disorders Who Died by Suicide

To explore the regulatory aspects of mRNAs and miRNAs in suicide, we integrated transcriptomic data from GEO datasets. The analysis of mRNA expression in the prefrontal cortex of suicide victims with major depressive disorder revealed a differential profile with 27 downregulated mRNAs, including HSPA1A, HSPA1B, DNAJB1, NR4A1, and GADD45B, which are involved in proteostasis, transcriptional regulation, and apoptosis. Functional enrichment analysis using KEGG and Gene Ontology (GO) revealed significant associations with synaptic plasticity, neuronal survival, and signaling pathways, including MAPK, TGF-β, Wnt, p53, and neurotrophins. Subsequently, using the GSE34120 GEO dataset of miRNAs from the frontal cortex of suicide victims, 105 dysregulated miRNAs were identified. The networks revealed compact regulatory modules with hsa-miR-576-3p, hsa-miR-493, and hsa-miR-550, as well as highly connected central nodes such as hsa-miR-30b, hsa-miR-16a-5p, hsa-miR-181a-5p, and hsa-miR-184. The integration of both profiles allowed the elaboration of miRNA–mRNA regulatory networks in which TP53, FOXO3, RELA, and FOS interact with multiple dysregulated miRNAs. These findings support the notion that suicide involves complex post-transcriptional dysregulation, particularly related to astrocytic function and neurotrophic signaling, with potential diagnostic and therapeutic applications.