Tumor Necrosis Factor-α Antagonist Reduces Apoptosis of Neurons and Oligodendroglia in Rat Spinal Cord Injury
Tumor Necrosis Factor-α Antagonist Reduces Apoptosis of Neurons and Oligodendroglia in Rat Spinal Cord Injury
复制标题
DOI：
10.1097/brs.0b013e3181f014ec
复制
发表时间：
2011-08-01
期刊：
影响因子：
3
通讯作者：
Baba, Hisatoshi
中科院分区：
文献类型：
--
作者：
Chen, Ke-Bing;Uchida, Kenzo;Baba, Hisatoshi
研究设计。研究肿瘤坏死因子(TNF)- α拮抗剂依那西普对大鼠脊髓损伤的作用，并探讨其可能的作用机制。目的：探讨依那西普在脊髓损伤病理级联反应中的作用及其对神经元和少突胶质细胞凋亡的抑制作用。背景资料摘要。依那西普最近被成功地用于治疗炎症性疾病。然而，关于其在脊髓损伤中抑制神经元和少突胶质细胞凋亡中的作用的研究很少。大鼠胸脊髓损伤后1小时腹腔注射依那西普或生理盐水（对照组）。采用免疫印迹和免疫组织化学方法检测TNF- α、TNF受体1 （TNFR1）和TNF受体2 （TNFR2）的表达和定位。在苏木精-伊红和luxol耐晒蓝（LFB）染色后，比较盐水组和依那西普组的脊髓组织损伤。应用Basso-Beattie-Bresnahan （BBB）量表评价依那西普给药后大鼠运动功能。计数末端脱氧核苷酸转移酶（TdT）介导的dutp -生物素缺口末端标记（TUNEL）阳性细胞，检测依那西普给药后对活性caspase-3和caspase-8的免疫反应性。免疫印迹和双免疫荧光染色显示，在脊髓损伤急性期给予依那西普后，tnf - α、TNFR1和TNFR2的表达受到抑制。脊髓损伤后2周，LFB染色显示依那西普治疗组可能有髓鞘形成，同时血脑屏障运动评分增加。双免疫荧光染色显示，依那西普给药后12小时至1周，灰质和白质tunel阳性神经元和少突胶质细胞明显减少。免疫印迹分析显示，脊髓损伤后活化的caspase-3和caspase-8过表达，依那西普明显抑制caspase-8的表达。结果表明依那西普能减轻脊髓损伤相关组织损伤，改善后肢运动功能，促进髓鞘再生。依那西普对脊髓损伤的积极作用可能是由于抑制tnf - α、TNFR1、TNFR2，激活caspase-3和caspase-8过表达，抑制神经元和少突胶质细胞凋亡。
Study Design. To examine the effects of a tumor necrosis factor (TNF)-alpha antagonist (etanercept) on rat spinal cord injury and identify a possible mechanism for its action.Objective. To elucidate the contribution of etanercept to the pathologic cascade in spinal cord injury and its possible suppression of neuronal and oligodendroglial apoptosis.Summary of Background Data. Etanercept has been recently used successfully for treatment of inflammatory disorders. However, only a few studies have examined its role in suppressing neuronal and oligodendroglial apoptosis in spinal cord injury.Methods. Etanercept or saline (control) was administered by intraperitoneal injection 1 hour after thoracic spinal cord injury in rats. The expressions and localizations of TNF-alpha, TNF receptor 1 (TNFR1), and TNF receptor 2 (TNFR2) were examined by immunoblot and immunohistochemical analyses. Spinal cord tissue damage between saline- and etanercept-treated groups was also compared after hematoxylin-eosin and luxol fast blue (LFB) staining. The Basso-Beattie-Bresnahan (BBB) scale was used to evaluate rat locomotor function after etanercept administration. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells were counted and the immunoreactivity to active caspase-3 and caspase-8 was examined after etanercept administration.Results. Immunoblot and double immunofluorescence staining revealed suppression of TNF-alpha, TNFR1, and TNFR2 expression after administration of etanercept in the acute phase of spinal cord injury. LFB staining demonstrated potential myelination in the etanercept-treated group from 2 week after spinal cord injury, together with an increased BBB locomotor score. Double immunofluorescence staining showed a significant decrease in TUNEL-positive neurons and oligodendroglia from 12 hour to 1 week in the gray and white matters after etanercept administration. Immunoblot analysis demonstrated overexpression of activated caspase-3 and caspase-8 after spinal cord injury, which was markedly inhibited by etanercept.Conclusion. Our results indicated that etanercept reduces the associated tissue damage of spinal cord injury, improves hindlimb locomotor function, and facilitates myelin regeneration. This positive effect of etanercept on spinal cord injury is probably attributable to the suppression of TNF-alpha, TNFR1, TNFR2, and activated caspase-3 and caspase-8 overexpressions, and the inhibition of neuronal and oligodendroglial apoptosis.