Xia Niange, Hua Yingjie, Li Jia, Chen Yanyan, Li Xueying, Lin Jiahe, Xu Huiqin, Xie Chenglong, Wang Xinshi
Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, South Baixiang, Ouhai District, Wenzhou, 325003, Zhejiang, China.
Neurochem Res. 2021 Jul;46(7):1674-1685. doi: 10.1007/s11064-021-03304-2. Epub 2021 Mar 27.
Blood-brain barrier (BBB) disruption has been recognized as an early hallmark of multiple sclerosis (MS) pathology. Our previous studies have shown that 2-(2-Benzofuranyl)-2-imidazoline (2-BFI) protected against experimental autoimmune encephalomyelitis (EAE), a classic animal model of MS. However, the potential effects of 2-BFI on BBB permeability have not yet been evaluated in the context of EAE. Herein, we aimed to investigate the effect of 2-BFI on BBB permeability in both an animal model and an in vitro BBB model using TNF-α to imitate the inflammatory damage to the BBB in MS. In the animal model, 2-BFI reduced neurological deficits and BBB permeability in EAE mice compared with saline treatment. The Western blot results indicated that 2-BFI not only alleviated the loss of the tight junction protein occludin caused by EAE but also inhibited the activation of the NR1-ERK signaling pathway. In an in vitro BBB model, 2-BFI (100 μM) alleviated the TNF-α-induced increase in permeability and reduction in expression of occludin in monolayer bEnd.3 cells. Similar protective effects were also observed after treatment with the NMDAR antagonist MK801. The Western blot results showed that the TNF-α-induced BBB breakdown and increase in NMDAR subunit 1 (NR1) levels and ERK phosphorylation could be blocked by pretreatment with 2-BFI or MK801. However, no additional effect was observed on BBB permeability or the expression of occludin and p-ERK after pretreatment with both 2-BFI and MK801. Our study indicates that 2-BFI alleviates the disruption of BBB in the context of inflammatory injury similar to that of MS by targeting NMDAR1, as well as by likely activating the subsequent ERK signaling pathway. These results provide further evidence for 2-BFI as a potential drug for the treatment of MS.
血脑屏障（BBB）破坏已被公认为是多发性硬化症（MS）病理的早期标志。我们之前的研究表明，2-（2-苯并呋喃基）-2-咪唑啉（2-BFI）可预防实验性自身免疫性脑脊髓炎（EAE），这是一种经典的MS动物模型。然而，尚未在EAE背景下评估2-BFI对BBB通透性的潜在影响。在此，我们旨在使用肿瘤坏死因子-α（TNF-α）模拟MS中BBB的炎性损伤，研究2-BFI在动物模型和体外BBB模型中对BBB通透性的影响。在动物模型中，与盐水处理相比，2-BFI降低了EAE小鼠的神经功能缺损和BBB通透性。蛋白质印迹结果表明，2-BFI不仅减轻了EAE引起的紧密连接蛋白闭合蛋白的丢失，还抑制了NR1-ERK信号通路的激活。在体外BBB模型中，2-BFI（100μM）减轻了TNF-α诱导的单层bEnd.3细胞通透性增加和闭合蛋白表达减少。在用N-甲基-D-天冬氨酸受体（NMDAR）拮抗剂MK801处理后也观察到了类似的保护作用。蛋白质印迹结果显示，用2-BFI或MK801预处理可阻断TNF-α诱导的BBB破坏以及NMDAR亚基1（NR1）水平升高和ERK磷酸化。然而，用2-BFI和MK801预处理后，在BBB通透性或闭合蛋白和磷酸化ERK的表达上未观察到额外的影响。我们的研究表明，2-BFI通过靶向NMDAR1以及可能激活随后的ERK信号通路减轻了类似于MS的炎性损伤背景下的BBB破坏。这些结果为2-BFI作为治疗MS的潜在药物提供了进一步的证据。
