LncRNA AP000654.1 attenuates cerebral ischemia-reperfusion injury by regulating mitophagy-mediated NLRP3 inflammasome activation

BACKGROUND: Ischemic stroke (IS) remains a leading cause of disability worldwide, and its therapeutic window is very narrow. Ischemia-reperfusion injury exacerbates secondary brain damage. Microglial NLRP3 inflammasome activation drives neuroinflammation, yet its upstream regulation requires further elucidation. We previously identified lncRNA AP000654.1 as significantly downregulated in the peripheral blood of stroke patients, prompting our investigation into its potential role in microglial biology. METHODS: Using an in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model in HMC3 human microglial cells, we investigated the role of lncRNA AP000654.1-previously identified as significantly downregulated in peripheral blood of stroke patients-in regulating microglial inflammatory responses. RESULTS: OGD/R treatment upregulated NLRP3 inflammasome-related genes, induced pyroptosis-associated changes, and altered mitophagy markers. LncRNA AP000654 0.1 overexpression suppressed this excessive mitophagy by inhibiting the PINK1-Parkin pathway, thereby improving mitochondrial function. This suppression subsequently attenuated NLRP3 inflammasome assembly and pyroptosis. Crucially, enforcing mitophagy with rapamycin exacerbated the injury, which was effectively rescued by lncRNA AP000654. CONCLUSION: LncRNA AP000654.1 is associated with suppression of excessive mitophagy-assocated mitochondrial stress and NLRP3 inflammasome activation in microglia, suggesting its potential relevance as a therapeutic target in ischemic stroke.