Neuroprotective effect of sulfhydryl reduction in a rat optic nerve crush model
Neuroprotective effect of sulfhydryl reduction in a rat optic nerve crush model
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DOI：
10.1167/iovs.05-0155
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发表时间：
2005-10-01
影响因子：
4.4
通讯作者：
Levin, LA
中科院分区：
文献类型：
--
作者：
Swanson, KI;Schlieve, CR;Levin, LA
目的.视网膜神经节细胞（retinal ganglion cell，RGC）在轴突损伤后死亡的信号转导部分依赖于活性氧的产生。在轴突切断的分离混合视网膜培养模型中，将RGC氧化还原状态向还原方向转移具有保护作用。本研究假设巯基还原剂三（2-羧乙基）膦（TCEP）对大鼠视神经损伤模型的RGCs具有保护作用。用荧光示踪剂DiI逆行标记出生后第4 ~ 5天Long-Evans大鼠的RGCs。在大约8周龄时，用镊子压碎每只大鼠的左视神经，然后立即将4 μ L TCEP（或单独的载体）注射到睫状体平坦部的玻璃体中，至最终浓度为6或60 μ M。右眼作为对照。在挤压后8或14天，处死动物，制备视网膜全标本，并对DiI标记的RGC进行计数。采用Bandeiraea simplicifolia凝集素（BSL-1）鉴定小胶质细胞。在用60 μ M TCEP处理的眼睛中，第8天存活的RGC的平均数量显著高于溶剂组（1250 +/- 156 vs. 669 +/- 109 cells/mm（2）; P = 0.0082）。在第14天记录了类似的结果。标记不是小胶质细胞吞噬垂死的RGC的结果。单独注射TCEP对RGC存活无毒性作用。巯基还原剂TCEP在视神经挤压模型中对RGCs具有神经保护作用。巯基氧化修饰可能是轴突损伤后活性氧介导RGC死亡的最终共同信号通路。
PURPOSE. The signaling of retinal ganglion cell (RGC) death after axotomy is partly dependent on the generation of reactive oxygen species. Shifting the RGC redox state toward reduction is protective in a dissociated mixed retinal culture model of axotomy. The hypothesis for the current study was that tris(2-carboxyethyl) phosphine (TCEP), a sulfhydryl reductant, would protect RGCs in a rat optic nerve crush model of axotomy.METHODS. RGCs of postnatal day 4 to 5 Long-Evans rats were retrogradely labeled with the fluorescent tracer DiI. At approximately 8 weeks of age, the left optic nerve of each rat was crushed with forceps and, immediately after, 4 mu L of TCEP (or vehicle alone) was injected into the vitreous at the pars plana to a final concentration of 6 or 60 mu M. The right eye served as the control. Eight or 14 days after the crush, the animals were killed, retinal wholemounts prepared, and DiI-labeled RGCs counted. Bandeiraea simplicifolia lectin (BSL-1) was used to identify microglia.RESULTS. The mean number of surviving RGCs at 8 days in eyes treated with 60 mu M TCEP was significantly greater than in the vehicle group (1250 +/- 156 vs. 669 +/- 109 cells/mm(2); P = 0.0082). Similar results were recorded at 14 days. Labeling was not a result of microglia phagocytosing dying RGCs. No toxic effect on RGC survival was observed with TCEP injection alone.CONCLUSIONS. The sulfhydryl-reducing agent TCEP is neuroprotective of RGCs in an optic nerve crush model. Sulfhydryl oxidative modification may be a final common pathway for the signaling of RGC death by reactive oxygen species after axotomy.