小鼠脑实质注射水通道蛋白4抗体所致的病理损伤

Lesions Caused by Intracerebral Injection of Aquaporin-4 Immunoglobulin G

【目的】探讨小鼠脑实质注射视神经脊髓炎谱系疾病(NMOSD)患者来源水通道蛋白4(AQP4)抗体(AQP4-IgG)造成的病理损伤,以及全身免疫状态对局部病灶的影响。【方法】于C57BL/6小鼠诱导实验性自身免疫性脑脊髓炎(EAE),在发病高峰期脑实质局部注射AQP4-IgG阳性患者血清来源的IgG和健康人补体(hC)(EAE+AQP4-IgG+hC组,n=5),以单纯脑实质注射IgG和hC(AQP4-IgG+hC组,n=5)与EAE小鼠脑实质注射生理盐水(NS;EAE+NS组,n=5)为对照组。通过免疫荧光方法,比较3组病灶中AQP4、星形胶质细胞胶质纤维酸性蛋白(GFAP)、少突胶质细胞髓鞘碱性蛋白(MBP),以及炎性细胞(T淋巴细胞、中性粒细胞和巨噬细胞)浸润等指标的异常。【结果】AQP4-IgG联合hC注射可以造成小鼠局灶性脑实质病理损伤,包括星形胶质细胞损伤,脱髓鞘以及炎性细胞浸润。与单纯AQP4-IgG+hC组相比,EAE+AQP4-IgG+hC组脑实质AQP4缺失面积(P=0.008)及GFAP缺失面积(P=0.016)显著增大,MBP缺失面积呈增大趋势;CD3+T细胞浸润的血管套数量、中性粒细胞浸润的血管套数量以及巨噬细胞浸润面积改变未达统计学差异。EAE+NS组亦可见注射周边星形胶质细胞增生,但无AQP4、GFAP与MBP缺失,炎性细胞主要分布在注射针道周围。【结论】小鼠脑实质注射AQP4-IgG联合hC可致显著局灶性病理损伤,而诱导EAE造成的全身免疫激活状态可加重该损伤;EAE联合AQP4-IgG局部注射能更好模拟NMOSD临床发病机制。

【Objective】To investigate the pathological damage caused by aquaporin-4antibody extracted from patients with neuromyelitis optica spectrum disorders(NMOSD)and the influence of systemic immune status on the local disease focus.【Methods】The C57BL/6mice were chose for establishing experimental autoimmune encephalomyelitis(EAE).During the peak at onset,serum-derived immunoglobulin G(IgG)from aquaporin-4(AQP4)IgG positive patients and healthy human complement(hC)were injected in the brain parenchyma(EAE+AQP4-IgG+hC group,n=5).The EAE induced mice injected with normal saline(EAE+NS group,n=5)and mice without EAE injected with AQP4-IgGand hC from healthy volunteers(AQP4-IgG+hC group,n=5)were served as control groups.The dramatic loss of AQP4,astrocyte glial fibrillary acidic protein(GFAP),oligodendrocyte myelin basic protein(MBP)and the infiltrationof inflammatory cells(T lymphocytes,neutrophils and macrophages)were compared with each group by using immunofluorescence,in order to find abnormal changes.【Results】Intracerebral injection of AQP4-IgG together with hC can cause NMO-like lesions,including astrocyte injury,demyelination and inflammatory cell infiltration.However,EAE mice model with intracerebral injection of AQP4-IgG and hC represented more significant loss of AQP4and GFAP(P=0.008and P=0.016,respectively)compared with mice without EAE induced.The area of MBP loss was also increased,while there′s no statistical difference.No statistical difference was also found in the number of vessels infiltrated with CD3+T cell,neutrophils and the area infiltrated with macrophage.Astrocyte proliferation existed in all groups,but no loss of AQP4,GFAP and MBP was found in EAE mice injected with NS.【Conclusion】Intracerebral injection of AQP4-IgG and hC can cause distinct pathological damage and the pathology can be promoted by immune system activated by EAE.Intracerebral injection of AQP4-IgG and hC can mimic the pathogenesis of NMOSD better in EAE mice model.