Upregulation of lncRNA CASC2 alleviates neuroinflammation in acute ischemic stroke and exhibits protective effects by targeting miR-155 (CASC2 role in AIS).

BACKGROUND: This study investigated the effects of dysregulated lncRNA CASC2 (CASC2) and miR-155 on clinical prognosis and neuronal cell activity in patients with acute ischemic stroke (AIS), as well as identified potential biomarkers that mediate inflammation levels and prognostic outcomes in AIS. METHODS: AIS cell models were established by inducing HT22 and BV-2 cells with OGD/R treatment. RT-qPCR quantified CASC2 and miR-155 expression. The levels of IL-1β, IL-6, IL-8 and TNF-α were detected by ELISA. Pearson correlation analysis was applied to assess the relationships between CASC2, miR-155 and NIHSS scores. ROC curve and binary Logistic analysis reflected the relevant indicators mediating the outcome of AIS patients. The targeting relationship between CASC2 and miR-155 was confirmed by DLR assay. The biological function of the cells was determined by CCK8 and FCM. RESULTS: CASC2 expression was significantly decreased in the serum of AIS patients, while miR-155 showed a positive trend, and this result was also reflected in the AIS patients with poor prognosis. CASC2 and miR-155 have reference value in predicting the prognosis of AIS patients. Functionally, CASC2 overexpression attenuated neuroinflammation and improved neuronal cell and microglia viability, whereas co-overexpression of miR-155 reversed these protective effects. CONCLUSIONS: CASC2 exerts a protective effect in AIS by sponging miR-155, thereby attenuating neuroinflammation and ameliorating clinical outcomes. CASC2 and miR-155 may serve as valuable prognostic biomarkers in AIS patients.