栝楼桂枝汤调节小胶质细胞活化后的表型转化缓解脑缺血再灌注大鼠模型的神经损伤

Gualou Guizhi Decoction Regulates Phenotypic Transformation of Activated Microgliaand Alleviates Neural Injury in a Rat Model of Cerebral Ischemia Reperfusion

目的基于小胶质细胞活化后的表型转化探讨栝楼桂枝汤缓解脑缺血再灌注大鼠模型的神经损伤。方法将SD大鼠随机分为假手术组10只和造模组20只。造模组建立脑缺血再灌注大鼠模型,假手术组仅钝性分离颈部肌肉血管,不插入线栓。Longa评分1~3分视为造模成功,采用抽签法将造模成功的大鼠分成模型组和栝楼桂枝汤组各10只。于造模成功后第2天开始灌胃,栝楼桂枝汤组按0.15 mg/(kg·d)给予栝楼桂枝汤药液灌胃,假手术组和模型组按10 mL/(kg·d)给予生理盐水灌胃,每日1次,持续灌胃1周。采用Longa评分进行神经功能评估;ELISA检测血清白细胞介素-1(IL-1)含量;HE染色法观察脑组织病理变化;Western blot检测M1表型标志物脑组织相容性复合物Ⅱ(MHC-Ⅱ)及M2表型标志物精氨酸酶1(Arg-1)蛋白表达量;免疫组化法检测脑组织离子钙接头蛋白(Iba-1)、微管相关蛋白2(MAP-2)的蛋白表达水平。结果与假手术组比较,模型组Longa评分明显提高(P<0.05),血清IL-1含量和脑组织MHC-Ⅱ、Iba-1蛋白表达均明显提高(P<0.05),Arg-1、MAP-2蛋白表达均明显降低(P<0.05)。与模型组比较,栝楼桂枝汤组Longa评分明显降低(P<0.05),血清IL-1含量和脑组织MHC-Ⅱ、Iba-1蛋白表达均明显降低(P<0.05),Arg-1、MAP-2蛋白表达均明显提高(P<0.05)。结论栝楼桂枝汤可能通过调控小胶质细胞活化后的表型,即上调M2表型,下调M1表型,抑制炎症反应,改善脑缺血再灌注后的神经细胞损伤。

Objective:To explore the effect of Gualou Guizhi decoction(GLGZD)on alleviating neural injury in a rat model of cerebral ischemia reperfusion based on phenotypic transformation of activated microglia.Methods:A total of 30 SD rats were randomly divided into sham surgery group(n=10)and modeling group(n=20).The modeling group established a rat model of cerebral ischemia reperfusion,while the sham surgery group only blunt-separated the cervical muscle vessels without suture insertion.The Longa scores of 1 to 3 were considered as successful modeling,and the successfully modeled rats were divided into model group(n=10)and GLGZD group(n=10)by drawing lots.On the second day after the successful modeling,the GLGZD group was given 0.15 mg/(kg·d)of GLGZD by gavage,the sham surgery group and model group were given 10 mL/(kg·d)of normal saline by gavage.The intervention in all groups was administered once daily,for one week.After the intervention,the Longa score was used to assess neurological function;the serum content of interleukin-1(IL-1)was measured by ELISA;the pathological changes of cerebral tissue was assessed by HE staining;the protein expression of major histocompatibility complex classⅡ(MHCⅡ)and arginase-1(Arg-1)was detected by Western blot;the protein expression level of ionized calcium binding adaptor molecule 1(Iba-1)and microtubule-associated protein-2(MAP-2)was detected by immunohistochemistry.Results:Compared with the sham surgery group,the Longa score of the model group significantly increased(P<0.05),and the serum content of IL-1 and the protein expression level of MHCⅡand Iba-1 in brain tissue significantly increased(P<0.05),while the protein expression of Arg-1 and MAP-2 significantly decreased(P<0.05).Compared with the model group,the Longa score of the GLGZD group significantly decreased(P<0.05),and the serum content of IL-1 and the protein expression level of MHCⅡand Iba-1 in brain tissue significantly decreased(P<0.05),while the protein expression of Arg-1 and MAP-2 significantly increased(P<0.05).Conclusion:GLGZD may inhibit inflammatory response and decrease neuronal damage after cerebral ischemia-reperfusion by regulating the activated phenotype of microglia by upregulating M2 phenotype and downregulating M1 phenotype.