局灶性脑缺血对腹部手术后大鼠海马星形胶质细胞活化和表皮生长因子受体表达的影响

Effects of focal cerebral ischemia on hippocampal astrocytes activation and epidermal growth factor receptor expression in rats undergoing abdominal surgery

目的探讨围术期急性缺血性卒中后,大鼠海马星形胶质细胞活化程度和表皮生长因子受体(EGFR)表达水平。方法30只18月龄雄性SD大鼠分为3组,假手术组(Sham)、腹部手术组(Surg)、腹部手术+局灶性脑缺血组(Surg+FCI),每组10只。分别予以仅麻醉不手术、麻醉下腹部手术、麻醉下腹部手术同时颈内动脉结扎处理。处理后24 h,大鼠心脏灌流处死全脑剥离,分离海马,固定切片后,进行免疫荧光染色和共聚焦观察,Image J计数IL-1R1阳性的神经元和小胶质细胞个数。组间比较采用单因素方差分析(ANOVA),两两比较采用独立样本t检验。结果Sham组、Surg组和Surg+FCI组大鼠海马DG区神经细胞核DAPI阳性染色数目分别为(76.80±9.51)、(74.80±11.66)、(77.10±5.55)个;同Sham组比较,Surg组阳性染色数目差异无统计学意义(F=0.66,P>0.05)。Sham组、Surg组和Surg+FCI组大鼠海马DG区胶质纤维酸性蛋白(GFAP)染色阳性的星形胶质细胞数目分别为(54.30±9.56)、(46.70±11.73)、(18.60±5.64)个,差异无统计学意义(F=2.52,P>0.05),Surg+FCI组阳性染色数目显著减少(F=103.48,P<0.05);同Surg组比较,Surg+FCI组阳性染色数目亦显著减少(F=46.62,P<0.05)。Sham组、Surg组和Surg+FCI组大鼠海马DG区EGFR阳性染色数目分别为(18.80±3.22)、(19.60±7.23)、(47.5±4.43)个。同Sham组比较,Surg组阳性染色数目差异无统计学意义(F=2.52,P>0.05),Surg+FCI组阳性染色数目显著升高(F=103.48,P<0.05);同Surg组比较,Surg+CI组阳性染色数目亦显著升高(F=46.62,P<0.05)。结论围术期急性缺血性卒中后,大鼠海马的星形胶质细胞活化程度降低,活化的星形胶质细胞上EGFR表达增多。

Objective To investigate the level of activation of astrocytes and the expression of epidermal growth factor receptor(EGFR)in the hippocampus of rats following acute ischemic stroke in the perioperative period.Methods A total of 3018-month-old male Sprague-Dawley rats were divided into three groups:a sham-operated group(Sham),an abdominal surgery group(Surg),and an abdominal surgery+focal cerebral ischemia group(Surg+FCI).The treatments involved anesthesia without surgery,anesthesia with abdominal surgery,and anesthesia with abdominal surgery plus internal carotid artery ligation,respectively.At 24th h post-surgery,the rats were perfused through the heart,the brains were extracted,and the hippocampi were isolated.Fixed sections underwent immunofluorescent staining and confocal observation.The number of IL-1R1 positive neurons and microglia were counted using Image J.Group comparisons were made using one-way ANOVA,with pairwise comparisons made using independent sample t-tests.Results The number of DAPI positive neuronal nuclei in the hippocampal DG region of the Sham,Surg,and Surg+FCI was(76.80±9.51),(74.80±11.66),and(77.10±5.55),respectively.No significant difference was observed between the Surg and the Sham(F=0.66,P>0.05),or between the Surg+FCI and the Sham(F=2.94,P>0.05).Similarly,no significant difference was found between the Surg+FCI and the Surg(F=4.42,P>0.05).The number of glial fibrillary acidic protein(GFAP)positive astrocytes in the hippocampal DG region was(54.30±9.56),(46.70±11.73),and(18.60±5.64)for the Sham,Surg,and Surg+FCI,respectively.No significant difference was found between the Surg and Sham(F=2.52,P>0.05),while a significant decrease was observed in the Surg+FCI compared to both the Sham(F=103.48,P<0.05)and Surg(F=46.62,P<0.05).The number of EGFR positive staining in the hippocampal DG region was(18.80±3.22),(19.60±7.23),and(47.5±4.43)for the Sham,Surg,and Surg+FCI,respectively.No significant difference was noted between the Surg and the Sham(F=2.52,P>0.05),whereas a significant increase was observed in the Surg+FCI compared to both the Sham(F=103.48,P<0.05)and Surg(F=46.62,P<0.05).Conclusion After acute ischemic stroke in the perioperative period,the activation level of astrocytes in the rat hippocampus decreased,and the expression of EGFR in activated astrocytes increased.