Department of Neurosurgery, University of Maryland School of Medicine, 22 S. Greene St., Suite S12D, Baltimore, MD, 21201-1595, USA.
Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
J Neuroinflammation. 2017 Sep 2;14(1):177. doi: 10.1186/s12974-017-0953-z.
In multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), inflammation is perpetuated by both infiltrating leukocytes and astrocytes. Recent work implicated SUR1-TRPM4 channels, expressed mostly by astrocytes, in murine EAE. We tested the hypothesis that pharmacological inhibition of SUR1 during the chronic phase of EAE would be beneficial.
EAE was induced in mice using myelin oligodendrocyte glycoprotein (MOG) 35-55. Glibenclamide (10 μg/day) was administered beginning 12 or 24 days later. The effects of treatment were determined by clinical scoring and tissue examination. Drug within EAE lesions was identified using bodipy-glibenclamide. The role of SUR1-TRPM4 in primary astrocytes was characterized using patch clamp and qPCR. Demyelinating lesions from MS patients were studied by immunolabeling and immunoFRET.
Administering glibenclamide beginning 24 days after MOG immunization, well after clinical symptoms had plateaued, improved clinical scores, reduced myelin loss, inflammation (CD45, CD20, CD3, p65), and reactive astrocytosis, improved macrophage phenotype (CD163), and decreased expression of tumor necrosis factor (TNF), B-cell activating factor (BAFF), chemokine (C-C motif) ligand 2 (CCL2) and nitric oxide synthase 2 (NOS2) in lumbar spinal cord white matter. Glibenclamide accumulated within EAE lesions, and had no effect on leukocyte sequestration. In primary astrocyte cultures, activation by TNF plus IFNγ induced de novo expression of SUR1-TRPM4 channels and upregulated Tnf, Baff, Ccl2, and Nos2 mRNA, with glibenclamide blockade of SUR1-TRPM4 reducing these mRNA increases. In demyelinating lesions from MS patients, astrocytes co-expressed SUR1-TRPM4 and BAFF, CCL2, and NOS2.
SUR1-TRPM4 may be a druggable target for disease modification in MS.
在多发性硬化症（MS）和实验性自身免疫性脑脊髓炎（EAE）中，浸润的白细胞和星形胶质细胞都会使炎症持续存在。最近的研究表明，SUR1-TRPM4 通道（主要由星形胶质细胞表达）在小鼠 EAE 中起作用。我们验证了这样一个假说，即在 EAE 的慢性期用 SUR1 的药理学抑制剂进行治疗会有好处。
使用髓鞘少突胶质细胞糖蛋白（MOG）35-55 诱导 EAE。在第 12 或 24 天后开始给予格列本脲（10μg/天）进行治疗。通过临床评分和组织检查确定治疗效果。使用 bodipy-格列本脲鉴定 EAE 病变内的药物。使用膜片钳和 qPCR 来研究原发性星形胶质细胞中的 SUR1-TRPM4 作用。通过免疫标记和免疫荧光共振能量转移（immunoFRET）研究 MS 患者的脱髓鞘病变。
在 MOG 免疫后 24 天开始给予格列本脲治疗，此时临床症状已经稳定，这改善了临床评分，减少了脱髓鞘、炎症（CD45、CD20、CD3、p65）和反应性星形胶质细胞增生，改善了巨噬细胞表型（CD163），并降低了肿瘤坏死因子（TNF）、B 细胞激活因子（BAFF）、趋化因子（C-C 基序）配体 2（CCL2）和一氧化氮合酶 2（NOS2）在腰髓白质中的表达。格列本脲在 EAE 病变内积累，对白细胞的隔离没有影响。在原代星形胶质细胞培养物中，TNF 加 IFNγ的激活诱导 SUR1-TRPM4 通道的新表达，并上调 Tnf、Baff、Ccl2 和 Nos2mRNA，格列本脲阻断 SUR1-TRPM4 减少了这些 mRNA 的增加。在 MS 患者的脱髓鞘病变中，星形胶质细胞共表达 SUR1-TRPM4 和 BAFF、CCL2 和 NOS2。
SUR1-TRPM4 可能是 MS 疾病修饰的一个有治疗潜力的靶点。
