TNF-α-induced optic nerve degeneration and nuclear factor-κB p65
TNF-α-induced optic nerve degeneration and nuclear factor-κB p65
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DOI：
10.1167/iovs.05-0299
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发表时间：
2006-04-01
影响因子：
4.4
通讯作者：
Lam, TT
中科院分区：
文献类型：
--
作者：
Kitaoka, Y;Kitaoka, Y;Lam, TT
目的.目的：建立肿瘤坏死因子（TNF）-α诱导的视神经轴突变性模型，探讨核因子（NF）-κ B B p65在轴突变性中的作用。在玻璃体内注射TNF-α后1天、1周或2周、或1个月或2个月对各组大鼠实施安乐死。进行神经丝或Thy-1阳性细胞、视网膜神经节细胞（用甲酚紫染色或用神经示踪剂逆行标记的扁平制剂）、轴突数量、髓鞘碱性蛋白免疫染色和TUNEL测定的形态学分析。Western blot和免疫组化检测视网膜和视神经NF-κ B B p65蛋白的表达。通过计数轴突数目来确定针对NF-κ B p65的反义寡核苷酸（AS ODN）和NF-κ B p65激活的抑制剂helenalin对TNF-α诱导的视神经变性的影响。玻璃体内注射TNF-α诱导明显的轴突损失和广泛的变性的轴突从2周到2个月后注射，而显着的视网膜神经节细胞损失仅在注射后2个月。NF-κ B p65在视神经中增加，但在视网膜中不增加，并且发现与小胶质细胞的标记物艾德-1和Iba 1共定位。用AS ODN或helenalin抑制NF-κ B p65可显著改善TNF-α介导的轴突丢失。TNF-α引起轴突变性，可能伴有视网膜神经节细胞体的延迟丢失。NF-κ B p65可能在轴突变性中起关键作用，可能涉及小胶质细胞。
PURPOSE. To characterize a model of optic nerve axonal degeneration induced by tumor necrosis factor (TNF)-alpha and to determine the role of nuclear factor (NF)-kappa B p65 in axonal degeneration.METHODS. Groups of rats were euthanatized at 1 day, 1 or 2 weeks, or 1 or 2 months after intravitreal injection of TNF-alpha. Morphometric analyses of neurofilament- or Thy-1-positive cells, retinal ganglion cells (flat preparations stained with cresyl violet or retrograde labeling with a neurotracer), the number of axons, immunostaining for myelin basic protein, and TUNEL assays were performed. Levels of NF-kappa B p65 protein in retina and optic nerve were determined by Western blot analysis and immunohistochemistry. The effects of antisense oligodeoxynucleotide (AS ODN) against NF-kappa B p65 and helenalin, an inhibitor of NF-kappa B p65 activation, on TNF-alpha-induced optic nerve degeneration were determined by counting the number of axons.RESULTS. Intravitreal injections of TNF-alpha induced obvious axonal loss and extensive degeneration of the axons from 2 weeks to 2 months after injection, whereas significant retinal ganglion cell loss was noted only at 2 months after injection. NF-kappa B p65 was increased in the optic nerve but not in the retina and was found to colocalize with ED-1 and Iba1, markers of microglia. Inhibition of NF-kappa B p65 with AS ODN or helenalin significantly ameliorated the effects of TNF-alpha-mediated axonal loss.CONCLUSIONS. TNF-alpha causes axonal degeneration with probable delayed loss of retinal ganglion cell bodies. NF-kappa B p65 may play a pivotal role in axonal degeneration, with the possible involvement of microglial cells.