LncRNA Tug1 Regulates Post-Stroke Microglial Pyroptosis via PINK1/Parkin-Mediated Mitophagy

Microglia, the central nervous system's primary immune cells, play a key role in the progression of cerebral ischemic stroke, particularly through their involvement in pyroptosis. The long non-coding RNA taurine up-regulated gene 1 (Tug1) is elevated during ischemic stroke and is critical in driving post-stroke neuroinflammation. However, the underlying molecular mechanisms remain unclear. This study explores the biological role of Tug1 and its potential mechanisms in regulating pyroptosis in microglia. We utilized an in vivo photothrombosis (PT) mice model and an in vitro oxygen-glucose deprivation and reperfusion (OGD/R) BV2 cell model to explore the mechanisms underlying ischemic stroke. Initially, we assessed the expression levels of Tug1 in the OGD/R model in vitro and the PT model in vivo. Subsequently, we investigated the impact of Tug1 on microglial pyroptosis by knocking down Tug1, silencing the PTEN-induced putative kinase 1 (Pink1) expression, and employing the mitophagy inhibitor mdivi-1. Tug1 exacerbated microglial pyroptosis by inhibiting mitophagy in both in vivo and in vitro models. The increase in mitophagy observed following Tug1 knockdown was reversed by either silencing Pink1 expression or using the mitophagy inhibitor mdivi-1. This reversal resulted in exacerbated pyroptosis and worsened neurological damage. Further mechanistic studies revealed that Tug1 knockdown significantly reduced microglial pyroptosis and alleviated neuronal damage by enhancing PINK1/Parkin-mediated mitophagy. For the first time, this study reveals that Tug1 promotes hypoxia-induced microglial pyroptosis by inhibiting PINK1/Parkin-mediated mitophagy, potentially providing a promising therapeutic target for ischemic inflammatory injury.