兔脊髓缺血再灌注后小胶质细胞活化及炎性细胞因子变化的研究

Investigation of Microglia Activation and Inflammatory Cytokine Changes in Experimental Rabbits After Spinal Cord Ischemia Reperfusion

目的:观察兔脊髓缺血再灌注后小胶质细胞活化及炎性细胞因子白细胞介素(IL)-6、IL-10、核转录因子(NF)-κB的变化规律,为后处理干预时机提供理论依据。方法:采用胸主动脉球囊阻断法建立兔脊髓缺血再灌注损伤模型。36周健康成年雄性新西兰大白兔54只,假手术组(n=6只)只置入球囊不阻断;48只脊髓缺血再灌注家兔按再灌注时间点分为8组:再灌注0h组、再灌注1h组、再灌注2h组、再灌注3h组、再灌注8h组、再灌注24h组、再灌注48h组、再灌注72h组,每组6只。分别于再灌注后0h、1h、2h、3h、8h、24h、48h和72h检测缺血段脊髓组织中正常神经元、凋亡神经元以及离子钙结合接头分子-1(Iba-1)、IL-6、IL-10、NF-κB的表达水平。结果:正常神经元数量随再灌注时间延长而减少;脊髓缺血再灌注损伤后8h原位末端转移酶标记(TUNEL)阳性神经元开始增多,再灌注24h组的TUNEL阳性神经元达高峰。再灌注2h组的Iba-1表达开始增多,再灌注8h组Iba-1表达达高峰;NF-κB于再灌注3h组开始增高,再灌注8h组NF-κB表达高峰;IL-6和IL-10表达均在再灌注24h组达高峰。脊髓缺血再灌注后NF-κB、IL-6、IL-10的表达水平与Iba-1呈相近的变化趋势。结论:脊髓缺血再灌注后小胶质细胞激活呈动态变化。NF-κB、IL-6、IL-10的表达水平与小胶质细胞激活显著正相关,在小胶质细胞激活前给予后处理可降低神经元损伤。

Objective： To observe the activation of microglia and the changing rule of inflammatory cytokine as IL-6, IL-10 and nuclear factor-κB （NF-κB） in experimental rabbits after spinal cord ischemia reperfusion （SCIR） injury in order to provide theoretical basis for post-conditioning time. Methods： Rabbit SCIR injury model was established by thoracic aorta balloon occlusion. 54 New Zealand male adult white rabbits were divided into 9 groups： Sham group （the animals received balloon implantation without occlusion）, SCIR-0h group （reperfusion was conducted at 0 hour of spinal cord ischemia）, SCIR-1h, -2h, -3h, -8h, -24h,-48h and -72h groups. n=6 in each group. The number of normal and apoptosis neurons, the levels of Iba-1, IL-6, IL-10 and NF-κB in spinal tissue were examined and compared among different groups respectively. Results： The number of normal neuron was decreasing with the extended reperfusion time, TUNEL-positive neuron began to increasing in SCIR-8h group and the peak was reached in SCIR-24h group. The expression of Iba-1 began to elevating in SCIR-2h group and the peak was obtained in SCIR-8h group; NF-κB began to rising in SCIR-3h group and the peak was observed in SCIR-8h group; both IL-6 and IL-10 arrived the peak in SCIR-24h group. The expressions of NF-κB, IL-6 and IL-10 were positively related to Iba-1 level. Conclusion： Microglia activation had dynamic changes in experimental SCIR rabbits and the expression levels of NF-κB, IL-6 and IL-10 were positively to microglia activation; post-conditioning time at front and back to microglia activation may reduce neuron injury.