TNFα拮抗剂减少脊髓损伤大鼠神经元和少突胶质细胞的凋亡

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Spine (Phila Pa 1976). 2011 Jan 8. [Epub ahead of print] Tumor Necrosis Factor-Alpha Antagonist Reduces Apoptosis of Neurons and Oligodendroglia in Rat Spinal Cord Injury. Chen KB, Uchida K, Nakajima H, Yayama T, Hirai T, Watanabe S, Guerrero AR, Kobayashi S, Ma WY, Liu SY, Baba H. *Department of Orthopaedics and Rehabilitation Medicine, Faculty of Medical Sciences, The University of Fukui, Fukui 910-1193, Japan; †Department of Spinal Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, People's Republic of China; ‡Servicio de Neurocirugia, Hospital Nacional Rosales, Universidad de El Salvador, San Salvador, El Salvador; ∫Department of Anaesthesiology, The Second Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510120, People's Republic of China. Abstract ABSTRACT: Study Design. To examine the effects of a tumor necrosis factor (TNF)-α antagonist (etanercept) on rat spinal cord injury and identify a possible mechanism for its action. Objective. To elucidate the contribution of etanercept to the pathological 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-α, 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 following haematoxylin-eosin and luxol fast blue (LFB) staining. The Basso-Beattie-Bresnahan (BBB) scale was used to evaluate rat locomotor function following 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 following etanercept administration. Results. Immunoblot and double immunofluorescence staining revealed suppression of TNF-α, 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 weeks 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 hours 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. Conclusions. 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-α, TNFR1, TNFR2, and activated caspase-3 and caspase-8 overexpressions, as well as the inhibition of neuronal and oligodendroglial apoptosis.

TNFα拮抗剂减少脊髓损伤大鼠神经元和少突胶质细胞的凋亡 Chen KB,et al.Spine (Phila Pa 1976). 2011 Jan 8.   研究设计：检验TNFα拮抗剂对大鼠脊髓损伤的作用，探讨可能机制。   目的：阐明依那西普在脊髓损伤中的病理作用，及其对神经元和少突胶质细胞凋亡的抑制作用。 背景资料简述：依那西普能成功治疗炎性疾病，但少有研究探讨其对脊髓损伤中神经元和少突胶质细胞凋亡的抑制作用。   方法：大鼠胸髓损伤后1小时，腹腔注射依那西普或生理盐水（对照）。采用免疫印迹法和免疫组化检测TNFα、TNF受体1（TNFR1）、TNF受体2（TNFR2）的表达和定位。通过HE染色和LFB染色，比较两组间脊髓组织损伤情况。采用Basso-Beattie-Bresnahan (BBB)评分评估注射依那西普后的运动功能。注射依那西普后，计数TUNEL阳性细胞，检测活动性caspase-3和caspase-8的免疫反应性。   结果：免疫印迹和双重免疫荧光染色显示在脊髓损伤急性期注射依那西普后，TNF-α、TNFR1和TNFR2表达受抑。LFB染色显示脊髓损伤2周后，依那西普治疗组表现出髓鞘形成的可能性，BBB运动评分升高。双重免疫荧光染色显示注射依那西普后12小时至1周，灰质和白质中TUNEL阳性神经元和少突胶质细胞显著减少。免疫印迹分析显示脊髓损伤后，活化的caspase-3和caspase-8过表达，而依那西普对其有明显抑制作用。   结论：本研究结果提示依那西普能减少脊髓损伤的相关组织损害，改善后肢运动功能，促进髓磷脂再生。依那西普对脊髓损伤的可能作用机制包括抑制TNF-α、TNFR1、TNFR2和活化的caspase-3、caspase-8过表达，抑制神经元和少突胶质细胞凋亡。