Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, China.
Department of Neurology, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, 610500, China.
Curr Neurovasc Res. 2023;20(2):197-206. doi: 10.2174/1567202620666230522155944.
BACKGROUND: NOD like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis is strongly related to cerebral ischemia/reperfusion (I/R) injury. DDX3X, the DEAD-box family's ATPase/RNA helicase, promotes NLRP3 inflammasome activation. However, whether DDX3X deficiency attenuates NLRP3 inflammasome-mediated pyroptosis induced by cerebral I/R injury. OBJECTIVES: This study investigated whether DDX3X deficiency attenuates NLRP3 inflammasomemediated pyroptosis in N2a cells after oxygen-glucose deprivation/ reoxygenation (OGD/R) treatment. METHODS: In vitro model of cerebral I/R injury, mouse neuro2a (N2a) cells subjected to OGD/R were treated with the knockdown of DDX3X. Cell counting kit-8 (CCK-8) assay and Lactate dehydrogenase (LDH) cytotoxicity assay were conducted to measure cell viability and membrane permeability. Double immunofluorescence was performed to determine the pyroptotic cells. Transmission electron microscopy (TEM) was used to observe morphological changes of pyroptosis. Pyroptosis-associated proteins were analyzed by Western blotting. RESULTS: The OGD/R treatment reduced cell viability, increased pyroptotic cells and released LDH compared to the control group. TEM showed membrane pore formation of pyroptosis. Immunofluorescence showed that GSDMD was translocated from the cytoplasm to the membrane after OGD/R treatment. Western blotting showed that the expression of DDX3X, and pyroptosis-related proteins (NLRP3, cleaved-Caspase1, and GSDMD-N) were increased after OGD/R treatment. Nevertheless, DDX3X knockdown markedly improved cell viability and reduced LDH release, expression of pyroptosis-related proteins, and N2a cells pyroptosis. DDX3X knockdown significantly inhibited membrane pore formation and GSDMD translocation from cytoplasm to membrane. CONCLUSION: This research demonstrates for the first time that DDX3X knockdown attenuates OGD/R induced NLRP3 inflammasome activation and pyroptosis, which implies that DDX3X may become a potential therapeutic target for cerebral I/R injury.
背景:核苷酸结合寡聚化结构域样受体蛋白 3(NLRP3)炎性小体介导的细胞焦亡与脑缺血再灌注(I/R)损伤密切相关。DEAD 盒家族的 ATP 酶/RNA 解旋酶 DDX3X 可促进 NLRP3 炎性小体的激活。然而,DDX3X 缺乏是否能减轻脑 I/R 损伤诱导的 NLRP3 炎性小体介导的细胞焦亡尚不清楚。
目的:本研究旨在探讨 DDX3X 缺乏是否能减轻氧葡萄糖剥夺/复氧(OGD/R)处理后的 N2a 细胞中 NLRP3 炎性小体介导的细胞焦亡。
方法:采用体外脑 I/R 损伤模型,用 DDX3X 敲低处理 N2a 细胞的 OGD/R。用细胞计数试剂盒-8(CCK-8)检测和乳酸脱氢酶(LDH)细胞毒性检测评估细胞活力和细胞膜通透性。双免疫荧光法检测焦亡细胞。透射电镜(TEM)观察焦亡细胞的形态变化。用 Western blot 法分析焦亡相关蛋白。
结果:与对照组相比,OGD/R 处理降低了细胞活力,增加了焦亡细胞数,并释放了 LDH。TEM 显示了焦亡的膜孔形成。免疫荧光显示,OGD/R 处理后 GSDMD 从细胞质转位到膜上。Western blot 显示,OGD/R 处理后 DDX3X 及其相关蛋白(NLRP3、切割的 Caspase1 和 GSDMD-N)的表达增加。然而,DDX3X 敲低显著改善了细胞活力,降低了 LDH 释放,减少了焦亡相关蛋白的表达,并减轻了 N2a 细胞的焦亡。DDX3X 敲低显著抑制了膜孔形成和 GSDMD 从细胞质向膜的转位。
结论:本研究首次证明,DDX3X 敲低可减轻 OGD/R 诱导的 NLRP3 炎性小体激活和细胞焦亡,提示 DDX3X 可能成为脑 I/R 损伤的潜在治疗靶点。
Eur J Pharmacol. 2024-1-5