肿瘤坏死因子-α诱导的视神经变性与核因子-κB p65

TNF-alpha-induced optic nerve degeneration and nuclear factor-kappaB p65.

作者信息

Kitaoka Yasushi, Kitaoka Yuka, Kwong Jacky M K, Ross-Cisneros Fred N, Wang Jiantao, Tsai Rong Kung, Sadun Alfredo A, Lam Tim T

机构信息

Department of Ophthalmology, Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

出版信息

Invest Ophthalmol Vis Sci. 2006 Apr;47(4):1448-57. doi: 10.1167/iovs.05-0299.

DOI:10.1167/iovs.05-0299

PMID:16565378

Abstract

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)-kappaB 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-kappaB p65 protein in retina and optic nerve were determined by Western blot analysis and immunohistochemistry. The effects of antisense oligodeoxynucleotide (AS ODN) against NF-kappaB p65 and helenalin, an inhibitor of NF-kappaB 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-kappaB 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-kappaB 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-kappaB p65 may play a pivotal role in axonal degeneration, with the possible involvement of microglial cells.

摘要

目的

表征由肿瘤坏死因子（TNF）-α诱导的视神经轴突变性模型，并确定核因子（NF）-κB p65在轴突变性中的作用。

方法

在玻璃体内注射TNF-α后1天、1或2周、或1或2个月对大鼠组实施安乐死。进行神经丝或Thy-1阳性细胞、视网膜神经节细胞（用甲酚紫染色的扁平制剂或用神经示踪剂进行逆行标记）的形态计量分析、轴突数量、髓鞘碱性蛋白免疫染色以及TUNEL检测。通过蛋白质印迹分析和免疫组织化学测定视网膜和视神经中NF-κB p65蛋白的水平。通过计数轴突数量来确定针对NF-κB p65的反义寡脱氧核苷酸（AS ODN）和NF-κB p65激活抑制剂海伦alin对TNF-α诱导的视神经变性的影响。

结果

玻璃体内注射TNF-α后2周至2个月诱导明显的轴突损失和轴突广泛变性，而仅在注射后2个月观察到明显的视网膜神经节细胞损失。视神经中NF-κB p65增加，但视网膜中未增加，且发现其与小胶质细胞标志物ED-1和Iba1共定位。用AS ODN或海伦alin抑制NF-κB p65可显著改善TNF-α介导的轴突损失的影响。