乙醇诱导的小胶质细胞TLR4/NLRP3神经炎症反应促进白细胞穿越血脑屏障浸润
Ethanol-Induced TLR4/NLRP3 Neuroinflammatory Response in Microglial Cells Promotes Leukocyte Infiltration Across the BBB.
作者信息
Alfonso-Loeches Silvia, Ureña-Peralta Juan, Morillo-Bargues M José, Gómez-Pinedo Ulises, Guerri Consuelo
机构信息
Molecular and Cellular Pathology of Alcohol, Prince Felipe Research Center, Eduardo Primo Yúfera 3, 46012, Valencia, Spain.
Department of Regenerative Medicine/Neurology and Neurosurgery, Neuroscience Institute, Clinic San Carlos Hospital, IdISSC, Profesor Martín Lagos, S/N, 28040, Madrid, Spain.
出版信息
Neurochem Res. 2016 Feb;41(1-2):193-209. doi: 10.1007/s11064-015-1760-5. Epub 2015 Nov 11.
We reported that the ethanol-induced innate immune response by activating TLR4 signaling triggers gliosis and neuroinflammation. Ethanol also activates other immune receptors, such as NOD-like-receptors, and specifically NLRP3-inflammasome in astroglial cells, to stimulate caspase-1 cleavage and IL-1β and IL-18 cytokines production. Yet, whether microglia NLRs are also sensitive to the ethanol effects that contribute to neuroinflammation is uncertain. Using cerebral cortexes of the chronic alcohol-fed WT and TLR4(-/-) mice, we demonstrated that chronic ethanol treatment enhanced TLR4 mediated-NLRP3/Caspase-1 complex activation, and up-regulated pro-inflammatory cytokines and chemokines levels. Ethanol-induced NLRP3-inflammasome activation and mitochondria-ROS generation were also observed in cultured microglial cells. The up-regulation of CD45(high)/CD11b(+) cell populations and matrix metalloproteinase-9 levels was also noted in the cortexes of the ethanol-treated WT mice. Notably, elimination of the TLR4 function abolished most ethanol-induced neuroinflammatory effects. Thus, our results demonstrate that ethanol triggers TLR4-mediated NLRP3-inflammasome activation in glial cells, and suggest that microglia stimulation may compromise the permeability of blood-brain barrier events to contribute to ethanol-induced neuroinflammation and brain damage.
我们报道,乙醇通过激活Toll样受体4(TLR4)信号通路诱导先天性免疫反应,引发神经胶质增生和神经炎症。乙醇还可激活其他免疫受体,如NOD样受体,特别是星形胶质细胞中的NLRP3炎性小体,以刺激半胱天冬酶-1的切割以及白细胞介素-1β(IL-1β)和白细胞介素-18(IL-18)细胞因子的产生。然而,小胶质细胞NLRs是否也对导致神经炎症的乙醇效应敏感尚不确定。利用慢性酒精喂养的野生型(WT)和TLR4基因敲除(-/-)小鼠的大脑皮层,我们证明慢性乙醇处理增强了TLR4介导的NLRP3/半胱天冬酶-1复合物的激活,并上调了促炎细胞因子和趋化因子的水平。在培养的小胶质细胞中也观察到乙醇诱导的NLRP3炎性小体激活和线粒体活性氧生成。在乙醇处理的野生型小鼠的大脑皮层中还发现CD45(高表达)/CD11b(+)细胞群和基质金属蛋白酶-9水平上调。值得注意的是,消除TLR4功能消除了大多数乙醇诱导的神经炎症效应。因此,我们的结果表明,乙醇在胶质细胞中触发TLR4介导的NLRP3炎性小体激活,并提示小胶质细胞的刺激可能损害血脑屏障的通透性,从而导致乙醇诱导的神经炎症和脑损伤。