The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami 1095 NW 14th Terrace, Miami, FL 33136, USA.
Brain. 2011 Sep;134(Pt 9):2736-54. doi: 10.1093/brain/awr199.
Tumour necrosis factor is linked to the pathophysiology of various neurodegenerative disorders including multiple sclerosis. Tumour necrosis factor exists in two biologically active forms, soluble and transmembrane. Here we show that selective inhibition of soluble tumour necrosis factor is therapeutic in experimental autoimmune encephalomyelitis. Treatment with XPro1595, a selective soluble tumour necrosis factor blocker, improves the clinical outcome, whereas non-selective inhibition of both forms of tumour necrosis factor with etanercept does not result in protection. The therapeutic effect of XPro1595 is associated with axon preservation and improved myelin compaction, paralleled by increased expression of axon-specific molecules (e.g. neurofilament-H) and reduced expression of non-phosphorylated neurofilament-H which is associated with axon damage. XPro1595-treated mice show significant remyelination accompanied by elevated expression of myelin-specific genes and increased numbers of oligodendrocyte precursors. Immunohistochemical characterization of tumour necrosis factor receptors in the spinal cord following experimental autoimmune encephalomyelitis shows tumour necrosis factor receptor 1 expression in neurons, oligodendrocytes and astrocytes, while tumour necrosis factor receptor 2 is localized in oligodendrocytes, oligodendrocyte precursors, astrocytes and macrophages/microglia. Importantly, a similar pattern of expression is found in post-mortem spinal cord of patients affected by progressive multiple sclerosis, suggesting that pharmacological modulation of tumour necrosis factor receptor signalling may represent an important target in affecting not only the course of mouse experimental autoimmune encephalomyelitis but human multiple sclerosis as well. Collectively, our data demonstrate that selective inhibition of soluble tumour necrosis factor improves recovery following experimental autoimmune encephalomyelitis, and that signalling mediated by transmembrane tumour necrosis factor is essential for axon and myelin preservation as well as remyelination, opening the possibility of a new avenue of treatment for multiple sclerosis.
肿瘤坏死因子与多种神经退行性疾病的病理生理学有关，包括多发性硬化症。肿瘤坏死因子有两种具有生物活性的形式，可溶性和跨膜型。在这里，我们表明，选择性抑制可溶性肿瘤坏死因子在实验性自身免疫性脑脊髓炎中具有治疗作用。用 XPro1595（一种选择性可溶性肿瘤坏死因子阻滞剂）治疗可改善临床结果，而用依那西普（etanercept）非选择性抑制两种形式的肿瘤坏死因子则不能提供保护。XPro1595 的治疗效果与轴突保存和髓鞘压缩改善有关，这与轴突特异性分子（如神经丝-H）的表达增加和与轴突损伤相关的非磷酸化神经丝-H 的表达减少有关。XPro1595 治疗的小鼠表现出明显的髓鞘再生，伴随着髓鞘特异性基因的表达升高和少突胶质细胞前体数量的增加。实验性自身免疫性脑脊髓炎后脊髓中肿瘤坏死因子受体的免疫组织化学特征表明，肿瘤坏死因子受体 1 在神经元、少突胶质细胞和星形胶质细胞中表达，而肿瘤坏死因子受体 2 则定位于少突胶质细胞、少突胶质细胞前体、星形胶质细胞和巨噬细胞/小胶质细胞。重要的是，在受进展性多发性硬化症影响的患者的脊髓死后组织中发现了类似的表达模式，这表明药物调节肿瘤坏死因子受体信号可能不仅是影响实验性自身免疫性脑脊髓炎小鼠病程的重要靶点，而且也是影响人类多发性硬化症的重要靶点。总之，我们的数据表明，选择性抑制可溶性肿瘤坏死因子可改善实验性自身免疫性脑脊髓炎后的恢复，跨膜肿瘤坏死因子介导的信号对于轴突和髓鞘保存以及髓鞘再生是必要的，为多发性硬化症的治疗开辟了新的途径。
