Indobufen ameliorates ischemic stroke by suppressing the signal transducer and activator of transcription 1/NIMA-related kinase 7/NOD-like receptor family pyrin domain-containing 3 signaling axis

Background: The neuronal Pyroptosis exacerbated neurological injury in ischemic stroke. Indobufen (IND), a clinically used agent for reducing ischemic stroke risk, was shown to suppress neuronal Pyroptosis in ischemic stroke. This study aimed to elucidate the precise mechanism by which IND regulates NOD-like Receptor family pyrin domain-containing 3 (NLRP3) inflammasome-mediated neuronal Pyroptosis.

Methods: SH-SY5Y cells underwent oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate ischemic damage. The binding of signal transducer and activator of transcription 1 (STAT1) at the NIMA-related kinase 7 (NEK7) promoter was assessed via chromatin immunoprecipitation and dual-luciferase reporter assay. Cell counting kit-8 was used to determine cell viability. The levels of inflammatory cytokines [interleukin (IL)-1β and IL-18] were evaluated using ELISA. Flow cytometry was employed to determine the rate of Pyroptosis. The expression of NLRP3 was assessed by immunofluorescence. Quantitative Real-Time PCR or Western blot was utilized to detect the expression of STAT1, NEK7, GSDMD-N, cleaved Caspase-1, and NLRP3.

Results: Treatment with IND significantly attenuated OGD/R-induced NLRP3 inflammasome activation and Pyroptosis in neurons. STAT1 served as the direct molecular target through which IND exerted its antipyroptotic effects in ischemic stroke. Mechanistically, STAT1 transcriptionally activated NEK7 expression under the ischemic stroke condition. IND suppressed neuronal Pyroptosis in ischemic stroke by inhibiting the STAT1/NEK7/NLRP3 signaling axis.

Conclusion: IND downregulated STAT1 to inhibit STAT1-mediated transcriptional activation of NEK7, thereby reducing NLRP3 inflammasome activation and ultimately mitigating neuronal Pyroptosis in ischemic stroke.

NIMA-related kinase 7; NOD-like receptor family pyrin domain-containing 3 inflammasome; ischemic stroke; pyroptosis; signal transducer and activator of transcription 1.