氯离子转运蛋白NKCC1在老年小鼠术后认知功能障碍中的作用  

Role of chloride transporter NKCC1 in postoperative cognitive dysfunction in aged mice

作　　者：史翠娜 王雷原 吴鑫淼 纪木火 SHI Cuina;WANG Leiyuan;WU Xinmiao;JI Muhuo(Department of Anesthesiology,the Second Affiliated Hospital of Nanjing Medical University,Nanjing 210011,China)

机构地区：[1]南京医科大学第二附属医院麻醉科,210011

出　　处：《临床麻醉学杂志》2022年第9期971-975,共5页Journal of Clinical Anesthesiology

基　　金：国家自然科学基金(81772126,81971892)。

摘　　要：目的探讨氯离子转运蛋白钠离子钾离子氯共转运体1(NKCCl)在老年小鼠术后认知功能障碍(POCD)中的作用。方法选择老年雄性C57BL/6小鼠40只,18~20月龄,体重28~32 g。将小鼠随机分为四组:对照+生理盐水组(N组),对照+布美他尼(NKCC1抑制剂)组(B组),POCD模型+生理盐水组(M组)和POCD模型+布美他尼组(MB组),每组10只。采用异氟醚麻醉和剖腹探查术建立POCD动物模型,于术后3~7 d行旷场与条件恐惧实验评估认知功能;行为学结束后采用Western blot法检测海马组织NKCC1、钾离子氯离子共转运体2(KCC2)、脑源性神经营养因子(BDNF)及突触后密度蛋白95(PSD95)的蛋白含量,免疫组织荧光检测海马组织CA1、CA3、DG区NKCC1免疫荧光强度。结果与N组比较,M组场景僵直时间明显缩短(P<0.05),海马NKCC1蛋白含量明显升高(P<0.05),BDNF、PSD95蛋白含量明显降低(P<0.05),海马组织CA1、CA3、DG区NKCC1免疫荧光强度明显增强(P<0.05)。N组和B组各指标差异均无统计学意义。与M组比较,MB组场景僵直时间明显延长(P<0.05),海马NKCC1蛋白含量明显降低(P<0.05),BDNF、PSD95蛋白含量明显升高(P<0.05),海马组织CA1、CA3、DG区NKCC1免疫荧光强度明显减弱(P<0.05)。结论NKCC1可能在老年小鼠POCD中发挥关键作用,其机制可能与突触相关蛋白BDNF与PSD95表达水平下调有关。Objective To explore the role of chloride transporter NKCC1 in postoperative cognitive dysfunction(POCD)in elderly mice.Methods Forty male C57BL/6 mice,aged 18-20 months,weighing 28-32 g,were used to establish POCD animal model by isoflurane anesthesia and exploratory laparotomy.Mice were randomly divided into four groups:control+normal saline group(group N),control+bumetanide(NKCC1 antagonist)group(group B),POCD model+saline group(group M)and POCD model+bumetanide group(group MB),10 mice in each group.The POCD model was assessed by open field test and fear conditioning test on 3-7 days after operation.Western blot was used to evaluate the protein content of hippocampal NKCC1,potassium-chloride cotransporter-2(KCC2),brain-derived neurotrophic factor(BDNF)and postsynaptic density protein 95(PSD95).The expression of NKCC1 in hippocampus was detected by immunofluorescence.Results Compared with group N,the freezing time was significantly shortened in group M(P<0.05),the expression of NKCC1 in hippocampus was significantly increased while the expressions of BDNF and PSD95 were decreased significantly in group M(P<0.05),the immunofluorescence intensity of NKCC1 in CA1,CA3 and DG areas of hippocampus were significantly increased in group M(P<0.05).There were no significantly differences in the above indexes between the two groups.Compared with group M,the freezing time was significantly prolonged in group MB(P<0.05),the expressions of NKCC1 was significantly decreased while BDNF and PSD95 increased significantly in group MB(P<0.05),the immunofluorescence intensity of NKCC1 in CA1,CA3 and DG areas of hippocampus were significantly decreased in group MB(P<0.05).Conclusion NKCC1 might play a key role in POCD in elderly mice,which may be related to the decreased synaptic associated protein BDNF and PSD95.

关 键 词：氯离子转运蛋白 钠离子钾离子氯共转运体1 术后认知功能障碍 老年 

分 类 号：R614[医药卫生—麻醉学]