The activation of microglia is an important cause of central nervous system (CNS) inflammatory cell infiltration and inflammatory demyelination in experimental autoimmune encephalomyelitis (EAE). Furthermore, the proinflammatory response induced by the NLR family pyrin domain containing 3 (NLRP3) inflammasome can be amplified in microglia after NLRP3 inflammasome activation. Autophagy is closely related to the inflammatory response. Caffeine exerts anti-inflammatory and autophagy-stimulating effects, but the specific mechanism remains unclear. This study examined the mechanism underlying the anti-inflammatory effect of caffeine on EAE. In this study, C57BL/6 mice were immunized to induce EAE and treated with caffeine to observe its effect on prognosis. The effects of caffeine on autophagy and inflammation were also analysed in mouse primary microglia (PM) and the BV2 cell line. The data demonstrated that caffeine reduced the clinical score, the infiltration of inflammatory cells, the demyelination level, and the activation of microglia in EAE mice. Furthermore, caffeine increased the LC3-II/LC3-I levels and decreased the NLRP3 and P62 levels in EAE mice, whereas the autophagy inhibitor 3-methylamine (3-MA) blocked these effects. In vitro, caffeine promoted autophagy by suppressing the mechanistic target of rapamycin (mTOR) pathway and inhibited activation of the NLRP3 inflammasome. However, autophagy-related gene 5 (ATG5)-specific siRNA abolished the anti-inflammatory effect of caffeine treatment in PM and BV2 cells. Taken together, these data suggest that caffeine exerts a newly discovered effect on EAE by reducing NLRP3 inflammasome activation via the induction of autophagy in microglia.

小胶质细胞的激活是实验性自身免疫性脑脊髓炎 (EAE) 中中枢神经系统 (CNS) 炎性细胞浸润和炎性脱髓鞘的重要原因。此外，在 NLRP3 炎症小体激活后，由 NLR 家族 pyrin 结构域 3 (NLRP3) 炎症小体诱导的促炎反应可以在小胶质细胞中放大。自噬与炎症反应密切相关。咖啡因具有抗炎和自噬刺激作用，但具体机制尚不清楚。本研究探讨了咖啡因对 EAE 抗炎作用的潜在机制。在本研究中，对 C57BL/6 小鼠进行免疫诱导 EAE 并用咖啡因处理以观察其对预后的影响。还在小鼠原代小胶质细胞 (PM) 和 BV2 细胞系中分析了咖啡因对自噬和炎症的影响。数据表明，咖啡因降低了 EAE 小鼠的临床评分、炎症细胞的浸润、脱髓鞘水平和小胶质细胞的活化。此外，咖啡因增加了 EAE 小鼠的 LC3-II/LC3-I 水平并降低了 NLRP3 和 P62 水平，而自噬抑制剂 3-甲胺 (3-MA) 阻止了这些作用。在体外，咖啡因通过抑制雷帕霉素 (mTOR) 通路的机制靶点和抑制 NLRP3 炎症小体的激活来促进自噬。然而，自噬相关基因 5 (ATG5) 特异性 siRNA 消除了咖啡因处理对 PM 和 BV2 细胞的抗炎作用。综合起来，