PD98059对心肺复苏后大鼠脑组织炎症因子及星形胶质细胞的影响

Effects of PD98059 on the cerebral inflammation cytokines and astrocyte in rats after cardiopulmonary resuscitation

目的探索PD98059对心脏骤停/心肺复苏(CA/CPR)后大鼠脑组织炎症因子及星形胶质细胞活性的影响。方法在24只健康SD大鼠中随机抽取8只仅进行麻醉和血管分离而不诱导CA(假手术组,Sham组)。其余16只大鼠麻醉后使用经食管电刺激诱导CA,自诱导起6 min后进行常规CPR。恢复自主循环的大鼠采用随机数字表法分成2组,分别注射PD98059(0.3 mg/kg,PD组,n=8)或者等体积的生理盐水(NS组,n=8)。24 h后对大鼠进行神经功能缺失评分(NDS);采用Western blot法检测大鼠脑皮质磷酸化细胞外调节激酶(p-ERK)表达及酸性胶质纤维蛋白(GFAP)表达水平;采用GFAP免疫组化染色计算脑组织切片中星形胶质细胞数目并观察其细胞形态及活性;ELISA法测定各组大鼠脑组织白细胞介素(IL)-6、IL-1β及肿瘤坏死因子(TNF)-α含量。结果与Sham组对比,NS组NDS评分明显降低,GFAP表达水平降低,星形胶质细胞数及活性减少,p-ERK/ERK比值明显升高,GFAP表达量明显降低,IL-6、IL-1β及TNF-α含量明显升高;与NS组对比,PD组NDS评分明显提高,GFAP表达水平升高,星形胶质细胞数增加,p-ERK/ERK比值明显降低,IL-6、IL-1β及TNF-α含量明显降低(P<0.05)。结论 PD98059可下调CA/CPR后脑组织炎症因子IL-6、IL-1β及TNF-α水平并恢复脑组织中星形胶质细胞的数量及活性。

Objective To explore the effect of PD98059 on the content of inflammatory cytokines in brain and the vitality of astrocyte after cardiac arrest/cardiopulmonary resuscitation(CA/CPR).Methods Eight rats were selected randomly in 24 healthy SD rats,only subjected to anesthesia and vascular separation without CA induction(Sham group),and the remaining 16 rats were given CA induction by trans-esophageal electrical stimulation after anesthesia.CPR was performed until 6 min later after the induction.The rats that recovered their spontaneous circulation were randomly divided into two groups,receiving the injection with either PD98059(0.3 mg/kg,PD group,n=8) or normal saline of the same volume(NS group,n=8).After 24 hours,neural function was assessed by neural defect scores(NDS).The expression of p-ERK and GFAP were detected by Western blot assay.The number and vitality of astrocyteon brain slices were assessed by GFAP immunohistochemical staining.The contents of IL-6,IL-1β and TNF-α were measured by relevant ELISA assay kits.Results Compared to the Sham group,NS group showed a significantly decreased NDS,both the expression levels of pERK and GFAP were decreased,and the number and vitality of astrocytes also decreased while the content of inflammation cytokines was increased.Compared to the NS group,the PD group showed a significantly increased NDS,both the expression levels of p-ERK and GFAP were increased,the number and vitality of astrocytes were increased while the content of inflammation cytokines was decreased(P <0.01).Conclusion PD98059 can down-regulate the levels of inflammatory cytokines IL-6,IL-1β and TNF-α in brain after CA/CPR,and resume the number and vitality of astrocytes in brain.