Seipin is involved in oxygen-glucose deprivation/reoxygenation induced neuroinflammation by regulating the TLR3/TRAF3/NF-κB pathway

Abstract

Seipin plays a crucial role in lipid metabolism and is involved in neurological disorders. However, the function and mechanism of action of seipin in acute ischemic stroke have not yet been elucidated. Here, we aimed to investigate the effect of seipin on neuroinflammation induced by oxygen-glucose deprivation/reoxygenation (OGD/R) and further explore the molecular mechanism by functional experiments. Our results revealed a significant decrease in seipin mRNA levels, accompanied by enhanced expression of TNF-α in patients with AIS, and a significant negative correlation between seipin and TNF-α was observed. Additionally, there was a negative correlation between seipin levels and the National Institutes of Health Stroke Scale (NIHSS) score. Furthermore, seipin levels were also decreased in middle cerebral artery occlusion/reperfusion (MCAO/R) mice and OGD/R-treated BV2 cells. RNA sequencing analysis showed that seipin knockdown altered the Toll-like receptor 3 (TLR3) signaling pathway. It was further confirmed in vitro that seipin knockdown caused significantly increased secretion of inflammatory factors including TNF-α, interleukin (IL)-1β, and interferon (IFN)-β. Meanwhile, seipin knockdown activated the Tlr3 signal pathway while this effect could be reversed by Tlr3 inhibitor in OGD/R treated BV2 cells. Furthermore, neuroinflammation induced by OGD/R was significantly reduced by seipin overexpression. Overall, our study demonstrate that seipin deficiency aggravates neuroinflammation by activating the TLR3/TRAF3/NF-κB signaling pathway after OGD/R stimuli, and suggest that seipin may be a potential therapeutic target for AIS.