Lipopolysaccharide-Activated Microglia Induce Dysfunction of the Blood-Brain Barrier in Rat Microvascular Endothelial Cells Co-Cultured with Microglia
Lipopolysaccharide-Activated Microglia Induce Dysfunction of the Blood-Brain Barrier in Rat Microvascular Endothelial Cells Co-Cultured with Microglia
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DOI：
10.1007/s10571-009-9446-7
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发表时间：
2010-03-01
影响因子：
4
通讯作者：
Kataoka, Yasufumi
中科院分区：
文献类型：
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作者：
Sumi, Noriko;Nishioku, Tsuyoshi;Kataoka, Yasufumi
血脑屏障（BBB）由脑毛细血管内皮细胞、星形胶质细胞、周细胞、小胶质细胞和神经元形成。在神经退行性疾病和炎症等病理条件下观察到BBB破坏与小胶质细胞激活平行。为了测试小胶质细胞的激活是否与BBB功能障碍有关，我们在体外与大鼠脑微血管内皮细胞（RBEC）和小胶质细胞共培养系统中评估了脂多糖（LPS）对BBB功能的影响。当LPS加入到RBEC/小胶质细胞共培养物的近腔侧6小时，浓度显示对RBEC单层没有影响时，跨内皮电阻降低，RBEC中对钠-荧光素的渗透性增加。紧密连接蛋白的免疫荧光染色表明，在LPS激活的小胶质细胞的存在下，RBEC的细胞间边界处的闭锁小带-1-，claudin-5-和occludin样免疫反应性被片段化。这些功能的变化诱导的LPS激活的小胶质细胞被阻断的烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶抑制剂，氯化二苯碘。目前的研究结果表明，LPS激活小胶质细胞，通过NADPH氧化酶产生活性氧引起BBB功能障碍。
The blood-brain barrier (BBB) is formed by brain capillary endothelial cells, astrocytes, pericytes, microglia, and neurons. BBB disruption under pathological conditions such as neurodegenerative disease and inflammation is observed in parallel with microglial activation. To test whether activation of microglia is linked to BBB dysfunction, we evaluated the effect of lipopolysaccharide (LPS) on BBB functions in an in vitro co-culture system with rat brain microvascular endothelial cells (RBEC) and microglia. When LPS was added for 6 h to the abluminal side of RBEC/microglia co-culture at a concentration showing no effects on the RBEC monolayer, transendothelial electrical resistance was decreased and permeability to sodium-fluorescein was increased in RBEC. Immunofluorescence staining for tight junction proteins demonstrated that zonula occludens-1-, claudin-5-, and occludin-like immunoreactivities at the intercellular borders of RBEC were fragmented in the presence of LPS-activated microglia. These functional changes induced by LPS-activated microglia were blocked by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, diphenyleneiodonium chloride. The present findings suggest that LPS activates microglia to induce dysfunction of the BBB by producing reactive oxygen species through NADPH oxidase.