Identification of inflammation‑associated circulating long non‑coding RNAs and genes in intracranial aneurysm rupture‑induced subarachnoid hemorrhage.

Ruptured intracranial aneurysm (IA)‑induced subarachnoid hemorrhage (SAH) triggers a series of immune responses and inflammation in the brain and body. The present study was conducted to identify additional circulating biomarkers that may serve as potential therapeutic targets for SAH‑induced inflammation. Differentially expressed (DE) long non‑coding RNAs (lncRNAs; DElncRNAs) and genes (DEGs) in the peripheral blood mononuclear cells between patients with IA rupture‑induced SAH and healthy controls were identified in the GSE36791 dataset. DEGs were used for weighted gene co‑expression network analysis (WGCNA), and SAH‑associated WGCNA modules were identified. Subsequently, an lncRNA‑mRNA regulatory network was constructed using the DEGs in SAH‑associated WGCNA modules. A total of 25 DElncRNAs and 1,979 DEGs were screened from patients with IA‑induced SAH in the GSE36791 dataset compared with the controls. A total of 11 WGCNA modules, including four upregulated modules significantly associated with IA rupture‑induced SAH were obtained. The DEGs in the SAH‑associated modules were associated with Gene Ontology biological processes such as 'regulation of programmed cell death', 'apoptosis' and 'immune response'. The subsequent lncRNA‑mRNA regulatory network included seven upregulated lncRNAs [HCG27, ZNFX1 antisense RNA 1, long intergenic non‑protein coding RNA (LINC)00265, murine retrovirus integration site 1 homolog‑antisense RNA 1, cytochrome P450 1B1‑AS1, LINC01347 and LINC02193] and 375 DEGs. Functional enrichment analysis and screening in the Comparative Toxicogenomics Database demonstrated that SAH‑associated DEGs, including neutrophil cytosolic factor (NCF)2 and NCF4, were enriched in 'chemokine signaling pathway' (hsa04062), 'leukocyte transendothelial migration' (hsa04670) and 'Fc gamma R‑mediated phagocytosis' (hsa04666). The upregulated lncRNAs and genes, including NCF2 and NCF4, in patients with IA rupture‑induced SAH indicated their respective potentials as anti‑inflammatory therapeutic targets.