环孢素A对大鼠急性脊髓损伤后炎症反应的影响

The Effect of Cyclosporin A on the Neuroinflammation Following Rat Spinal Cord Injury

目的探讨环孢素A(CsA)在大鼠急性脊髓损伤后神经炎症反应中的作用,为CsA合理地用于脊髓损伤的临床治疗提供理论依据。方法成年雄性SD大鼠75只,随机分为假手术组(sham组)、环孢素A治疗组(CsA组)、生理盐水治疗组(NS组)。采用行为学评估、H-E染色、qRT-PCR及免疫组织化学技术检测脊髓损伤大鼠的后肢运动功能恢复、组织损伤面积、促炎因子[白细胞介素(IL)-1β,IL-6,肿瘤坏死因子-α(TNF-α)]的表达。结果行为学评估显示,随着观察时间点推移,CsA组和NS组大鼠的BBB评分逐渐升高,后肢运动功能逐渐恢复,但CsA组大鼠的BBB评分自脊髓损伤后14 d起均显著高于NS组(P<0.01)。H-E染色显示,脊髓损伤后28 d CsA组的损伤面积百分比显著低于NS组(P<0.01)。qRT-PCR显示,脊髓损伤后6 h和1 d CsA组脊髓的IL-1β,IL-6及TNF-α的mRNA水平显著低于NS组(P<0.01)。免疫组织化学显示,CsA组脊髓损伤后6 h和1 d的IL-1β,IL-6及TNF-α在脊髓灰质神经元及神经胶质细胞的胞质表达的相对蛋白水平显著低于NS组(P<0.01)。结论CsA可能通过减轻脊髓损伤后局部炎症反应而减缓继发性脊髓损伤的进展。

Objective To investigate the role of cyclosporine A on neuroinflammation following rat spinal cord injury,to provide theoretical basis for the rational use of CsA in the clinical treatment of spinal cord injury.Methods Seventy-five adult male Sprague-Dawley(SD)rats were randomly assigned to sham-operated rats(sham group),CsA-treated SCI rats(CsA group),and normal saline-treated SCI rats(NS group).Behavioral assessment,H-E staining,qRT-PCR and immunohistochemistry were used to evaluate SCI rats′motor function,lesion tissue and expression of IL-1β,IL-6,and TNF-α.Results During the observation period,as illustrated by increased BBB scores,hindlimb locomotor activity gradually improved in CsA group and NS group.In addition,compared with NS group,BBB scores from CsA group significantly increased starting from day-14 after SCI(P<0.01).Transverse sections stained by H-E from CsA group and NC group revealed obvious various size cystic cavities,and glia scar formation surrounded cavity.More importantly,compared with NC group,the lesioned volume of epicenter from CsA group significantly decreased(P<0.01).qRT-PCR data from injured spinal cord 6 h and 1 d post SCI showed that the mRNA levels of IL-1β,IL-6,and TNF-αwere significantly reduced by CsA treatment in comparison to NS group(P<0.01).Similarly,immunohistochemistry data 6 h and 1d post-injury revealed that IL-1β,IL-6,and TNF-αwere mainly localized in the cytoplasm of gray matter neurons and glial cells.Moreover,the percentage of positive cells in CsA group demonstrated a significant decrease in comparison to NS group(P<0.01).Conclusion CsA may attenuate spinal cord injury via neuroinflammation reduction.