METHODS: Monoclonal anti-NMDAR antibodies or control antibodies were infused into the lateral ventricle of MyD88 knockout mice (MyD88-/-) and control C56BL/6J mice (wild type [WT]) via osmotic minipumps for 2 weeks. Seizure responses were measured by electroencephalography. Upon completion of the infusion, the motor, anxiety, and memory functions of the mice were assessed. Astrocytic (glial fibrillary acidic protein [GFAP]) and microglial (ionized calcium-binding adaptor molecule 1 [Iba-1]) activation and transcriptional activation for the principal inflammatory mediators involved in seizures were determined using immunohistochemistry and quantitative real-time polymerase chain reaction, respectively.
RESULTS: As shown before, 80% of WT mice infused with anti-NMDAR antibodies (n = 10) developed seizures (median = 11, interquartile range [IQR] = 3-25 in 2 weeks). In contrast, only three of 14 MyD88-/- mice (21.4%) had seizures (0, IQR = 0-.25, p = .01). The WT mice treated with antibodies also developed memory loss in the novel object recognition test, whereas such memory deficits were not apparent in MyD88-/- mice treated with anti-NMDAR antibodies (p = .03) or control antibodies (p = .04). Furthermore, in contrast to the WT mice exposed to anti-NMDAR antibodies, the MyD88-/- mice had a significantly lower induction of chemokine (C-C motif) ligand 2 (CCL2) in the hippocampus (p = .0001, Sidak tests). There were no significant changes in the expression of GFAP and Iba-1 in the MyD88-/- mice treated with anti-NMDAR or control antibodies.
CONCLUSIONS: These findings suggest that MyD88-mediated signaling contributes to the seizure and memory phenotype in anti-NMDAR encephalitis and that CCL2 activation may participate in the expression of these features. The removal of MyD88 inflammation may be protective and therapeutically relevant.
方法:通过渗透微型泵将单克隆抗NMDAR抗体或对照抗体注入MyD88敲除小鼠(MyD88-/-)和对照C56BL/6J小鼠(野生型[WT])的侧脑室2周。癫痫反应通过脑电图测量。输液完成后,电机,焦虑,并评估小鼠的记忆功能。使用免疫组织化学和定量实时聚合酶链反应确定与癫痫发作有关的主要炎症介质的星形胶质细胞(神经胶质原纤维酸性蛋白[GFAP])和小胶质细胞(离子化钙结合衔接分子1[Iba-1])激活和转录激活。分别。
结果:如前所述,80%输注抗NMDAR抗体的WT小鼠(n=10)出现癫痫发作(中位数=11,四分位距[IQR]=2周内3-25)。相比之下,14只MyD88-/-小鼠中只有3只(21.4%)出现癫痫发作(0,IQR=0-.25,p=.01)。用抗体处理的WT小鼠在新的物体识别测试中也出现了记忆丧失,而在用抗NMDAR抗体(p=.03)或对照抗体(p=.04)治疗的MyD88-/-小鼠中,这种记忆缺陷并不明显。此外,与暴露于抗NMDAR抗体的WT小鼠相反,MyD88-/-小鼠对海马中趋化因子(C-C基序)配体2(CCL2)的诱导显着降低(p=.0001,Sidak测试)。在用抗NMDAR或对照抗体处理的MyD88-/-小鼠中,GFAP和Iba-1的表达没有显著变化。
结论:这些研究结果表明,MyD88介导的信号传导有助于抗NMDAR脑炎的癫痫发作和记忆表型,CCL2激活可能参与这些特征的表达。MyD88炎症的去除可以是保护性和治疗相关的。