二氢杨梅素通过JAK2/STAT3通路调控小胶质细胞活化对异氟醚所致成年小鼠早期认知功能障碍的影响

Effect of dihydromyricetin on isoflurane-induced early cognitive dysfunction in adult mice by regulating microglia activation through JAK2/STAT3 pathway

目的:探究二氢杨梅素(DMY)通过蛋白酪氨酸激酶2(JAK2)/信号转导和转录活化因子3(STAT3)通路调控小胶质细胞活化对异氟醚所致成年小鼠早期认知功能障碍的影响。方法:将50只雄性C57BL/6小鼠分为对照组、异氟醚组、DMY-L组(100 mg/kg DMY)、DMY-H组(200 mg/kg DMY)、DMY-H+AG490组(JAK2抑制剂AG490 0.4 mg/kg),DMY-L组、DMY-H组、DMY-H+AG490组小鼠灌胃相应剂量DMY或AG490,对照组、异氟醚组灌胃等量生理盐水,为时1周(1次/d);通过旷场实验、新旧事物识别实验及水迷宫实验观察各组小鼠行为学变化情况;免疫组化法测定海马组织离子钙结合衔接分子1(Iba1)表达;ELISA检测海马组织IL-10及IL-1β水平;Western blot检测海马组织CD68、诱导型一氧化氮合酶(iNOS)、精氨酸酶蛋白及JAK2/STAT3通路蛋白水平。结果:与对照组相比,异氟醚组小鼠站立次数、运动路程、穿越平台次数、IL-10水平、精氨酸酶表达显著减少,逃避潜伏期、海马组织Iba1阳性细胞数、IL-1β水平、CD68、iNOS、p-STAT3/STAT3及p-JAK2/JAK2表达显著增加(P<0.05);与异氟醚组相比,DMY-L组、DMY-H组小鼠站立次数、运动路程、穿越平台次数、IL-10水平、精氨酸酶表达显著增加,逃避潜伏期、海马组织Iba1阳性细胞数、IL-1β水平、CD68、iNOS、p-STAT3/STAT3及p-JAK2/JAK2表达显著减少(P<0.05);与DMY-H组相比,DMY-H+AG490组站立次数、运动路程、穿越平台次数、IL-10水平、精氨酸酶表达显著增加,逃避潜伏期、海马组织Iba1阳性细胞数、IL-1β水平、CD68、iNOS、p-STAT3/STAT3、p-JAK2/JAK2表达显著减少(P<0.05)。结论:DMY可能通过抑制JAK2/STAT3通路抑制小胶质细胞活化,从而改善异氟醚所致的成年小鼠早期认知功能障碍。

Objective:To explore the effect of dihydromyricetin(DMY)on isoflurane-induced early cognitive dysfunction in adult mice by regulating microglia activation through Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)pathway.Methods:A total of 50 male C57BL/6 mice were divided into control group,isoflurane group,DMY-L group(100 mg/kg DMY),DMY-H group(200 mg/kg DMY)and DMY-H+AG490 group(JAK2 inhibitor AG4900.4 mg/kg),mice in DMY-L group,DMY-H group and DMY-H+AG490 group were given corresponding dose of DMY or AG490 by gavage,control group and isoflurane group were given the same amount of normal saline,for 1 week(1 time/d);open field experiment,new and old object recognition experiment and water maze experiment were used to observe behavioral changes of mice in each group;immunohistochemical method was used to measure expression of ionized calcium binding adapter molecule 1(Iba1)in hippocampus;ELISA was used to detect levels of IL-10 and IL-1βin hippocampus;Western blot was used to detect levels of CD68,inducible nitric oxide synthase(iNOS),Arginase protein and JAK2/STAT3 pathway proteins in hippocampal tissues.Results:Compared with control group,the number of standing times,exercise distance,the number of crossing platform times,IL-10 level,and Arginase expressions were reduced significantly in isoflurane group,the escape latency,the number of Iba1 positive cells in hippocampus,IL-1βlevel,CD68,iNOS,p-STAT3/STAT3 and p-JAK2/JAK2 expressions were increased significantly(P<0.05);compared with isoflurane group,the number of standing times,exercise distance,the number of crossing platform times,IL-10 level,and Arginase expression were increased significantly in DMY-L and DMY-H groups,the escape latency,the number of Iba1 positive cells in hippocampus,IL-1βlevel,CD68,iNOS,p-STAT3/STAT3 and p-JAK2/JAK2 expressions were reduced significantly(P<0.05);compared with DMY-H group,the number of standing times,exercise distance,the number of crossing platform times,IL-10 level,and Arginase expression were increased significantly in DMY-H+AG 490 group,the escape latency,the number of Iba 1 positive cells in hippocampus,IL-1βlevel,CD 68,iNOS,p-STAT 3/STAT 3 and p-JAK 2/JAK 2 expressions were reduced significantly(P<0.05).Conclusion:DMY may reduce the activation of microglia by inhibiting JAK 2/STAT 3 pathway,thereby improving isoflurane-induced early cognitive dysfunction in adult mice.