Copray J C V M, Küst B M, Mantingh-Otter I, Boddeke H W G M
Department of Medical Physiology, University of Groningen, Groningen, the Netherlands.
Neuropathol Appl Neurobiol. 2005 Dec;31(6):600-9. doi: 10.1111/j.1365-2990.2005.00656.x.
Feeding C57Bl/6 J mice the copper chelator cuprizone leads to selective apoptosis of mature oligodendrocytes and concomitant demyelination predominantly in the corpus callosum. The process of oligodendrocyte apoptosis in this animal model for multiple sclerosis (MS) involves early microglial activation, but no infiltration of T-lymphocytes. Therefore, this model could mimic early stages of oligodendrocyte degeneration Affected oligodendrocytes express the common neurotrophin receptor, p75(NTR), a 'stress-receptor' which under certain circumstances can induce apoptosis. Only affected oligodendrocytes in MS lesions and MS animal models express this receptor. In order to study the significance of p75(NTR) in the fate of oligodendrocytes, we have exposed wild-type as well as p75(NTR)-knockout mice to a 0.2% (w/w) cuprizone diet and performed a comparative immunohistochemical analysis of the corpus callosum at various time points. Surprisingly, our results show that the absence of p75(NTR) did not alter cuprizone-induced oligodendrocyte death (and subsequent de- or remyelination). Apparently, intracellular apoptosis pathways in adult oligodendrocytes do not require p75(NTR) activated signal transduction in the absence of T-lymphocytes and T-lymphocyte derived cytokines.
给C57Bl/6 J小鼠喂食铜螯合剂曲吡酮会导致成熟少突胶质细胞选择性凋亡,并伴随主要在胼胝体的脱髓鞘。在这个多发性硬化症(MS)动物模型中,少突胶质细胞凋亡过程涉及早期小胶质细胞激活,但没有T淋巴细胞浸润。因此,这个模型可以模拟少突胶质细胞变性的早期阶段。受影响的少突胶质细胞表达常见的神经营养因子受体p75(NTR),这是一种“应激受体”,在某些情况下可以诱导凋亡。只有MS病变和MS动物模型中受影响的少突胶质细胞表达这种受体。为了研究p75(NTR)在少突胶质细胞命运中的意义,我们将野生型以及p75(NTR)基因敲除小鼠暴露于0.2%(w/w)曲吡酮饮食中,并在不同时间点对胼胝体进行了比较免疫组织化学分析。令人惊讶的是,我们的结果表明p75(NTR)的缺失并没有改变曲吡酮诱导的少突胶质细胞死亡(以及随后的脱髓鞘或再髓鞘化)。显然,在没有T淋巴细胞和T淋巴细胞衍生细胞因子的情况下,成年少突胶质细胞的细胞内凋亡途径不需要p75(NTR)激活的信号转导。