骨髓单个核细胞对脑梗死大鼠炎症反应的影响

The effect of bone marrow mononuclear cells on inflammatory response after cerebral infarction in rats

目的探讨骨髓单个核细胞(BMMNCs)是否通过抑制脑梗死大鼠脑内的炎症反应来发挥神经保护作用。方法选择健康雄性SD大鼠,体质量为250~300 g,线栓法制备永久性大脑中动脉闭塞模型(p MCAO),造模成功后,随机分为4组:假手术组(Sham组)、模型组(Model组)、溶剂组(Vehicle组)、骨髓单个核细胞组(BMMNCs组)。其中BMMNCs组于造模24 h后经尾静脉注射含1×107BMMNCs的PBS细胞悬液200μl;溶剂组注射等量的PBS溶液,分别于24 h、72 h、7 d采用Zea-Longa法进行神经功能评分;干湿重法检测脑组织含水量;TTC法测定脑梗死体积;免疫组化、Western blot技术检测炎性介质环氧化酶-2(COX-2)、白介素-1β(IL-1β)的表达情况。结果 (1)各时间点模型组Zea-Longa评分、脑组织含水量和脑梗死体积均明显高于假手术组(P<0.05),BMMNCs组低于模型组,高于假手术组(P<0.05),模型组与溶剂组相比无差异(P>0.05);(2)各时间点模型组COX-2和IL-1β水平明显均高于假手术组(P<0.05),BMMNCs组低于模型组,高于假手术组(P<0.05),模型组与溶剂组相比无差异(P>0.05)。结论骨髓单个核细胞移植可通过抑制梗死后脑内免疫炎症反应,显著改善脑梗死大鼠的神经功能,这一治疗作用可能与下调COX-2、IL-1β的表达有关。

Objective To investigate whether the bone marrow mononuclear cells（ BMMNCs） exert neuroprotective effects by inhibiting the inflammatory response in rats with cerebral infarction. Methods All SD rats,weighted 250 ~300 g,was established a permanent occlusion of middle cerebral artery（ p MCAO） model by using the suture method. The successful models were randomly divided into four groups： Sham group,Model group,Vehicle group,BMMNCs group. At the time of 24 h after the successful modeling,200 μl PBS solution containing 1 × 107 BMMNCs was injected into BMMNCs group via the tail vein,vehicle group was injected the same amount of PBS. At the time points of 24 h,72 h and 7 d,ZeaLonga method was used to evaluate the neurological function,and the brain water content and cerebral infarction volume were also measured by dry-wet weight method and TTC method,the expression of COX-2 and IL-1β were detected by immunohistochemistry and Western blot technique. Results（ 1） At each time point,the Zea Longa,brain water content and infarct volume in the model group were significantly higher than those in the sham operation group（ P〈0. 05）,while the ZeaLonga,brain water content and infarct volume in the BMMNCs group were lower than those in the model group,higher than those in the sham operation group（ P〈0. 05）. There was no difference in comparison between the model group and vehicle group（ P〈0. 05）.（ 2） At each time point,the levels of COX-2 and IL-1β in the model group were significantly higher than those in the sham operation group（ P〈0. 05）. While the COX-2 and IL-1β expression levels in the BMMNCs group were lower than those in the model group,higher than those in the sham operation group（ P〈0. 05）. There was no difference in comparison between the model group and the vehicle group（ P〉0. 05）. Conclusion The neuroprotective effect of BMMNCs transplantation on cerebral infarction may inhibit inflammatory reaction in brain immune,significantly improve the neurological functions of rats with cerebral infarction,the treatment effect may be associated with the down-regulation of COX-2 and IL-1β expression.