NADPH氧化酶2活化介导脑内微清蛋白表达下降在小鼠脓毒症相关性脑病中的作用

Role of NOX2 activation-mediated decreased expression of parvalbumin in the sepsis associated encephalopathy

目的观察脑内NADPH氧化酶2(NOX2)介导微清蛋白(PV)表达变化在脓毒症相关性脑病(SAE)中的作用,并探讨其可能机制。方法采用盲肠结扎穿孔法(CLP)建立SAE模型。60只成年雄性C57BL/6小鼠随机分为四组:对照+溶剂组(A组,n=10)、对照+夹竹桃麻素(apocynin,APO)组(B组,n=10)、CLP+溶剂组(C组,n=20)及CLP+夹竹桃麻素组(D组,n=20)。B、D组术后1h腹腔注射APO 5mg/kg,以后每天注射一次直至术后第10天;其余两组注射等容溶剂。术后第13天行旷场实验测试及条件性恐惧实验训练,第14天行条件性恐惧测试。行为学测试后2h取小鼠皮层及海马,采用Western blot检测其PV和NOX2两个亚基gp91phox、p22phox的表达。结果旷场实验中,四组小鼠总探索路程差异无统计学意义。与A、B组比较,C组中央格停留时间和僵直反应时间明显缩短,并伴有皮层及海马PV表达明显下降,而gp91phox及p22phox表达明显增高(P<0.05);与C组比较,D组中央格停留时间和僵直反应时间明显延长,并伴有皮层及海马PV表达明显上升,而gp91phox及p22phox表达明显降低(P<0.05)。结论脑内NOX2活化介导PV表达降低可能参与SAE发病。

Objective To observe the role of parvalbumin（PV）expression in a mouse model of sepsis associated encephalopathyand to explore the possible mechanism.Methods Cecal ligation and puncture（CLP）was applied to establish the sepsis model.Sixty adult male C57BL/6mice were randomized into four groups：control＋vehicle group（group A,n=10）,control＋APO group（group B,n=10）,CLP＋vehicle group（group C,n=20）,and CLP＋APO group（group D,n=20）.In groups B and D,mice were treated with apocynin（APO,5mg/kg）by intraperitoneal injection beginning at 1h after the surgery and once a day for consecutive 10 d.The animals in the other two groups received the equal volume of vehicle.Open field and the training of fear conditioning were performed 13 dafter the surgery,while the contextual and cued fear conditioning tests were assessed 14 dafter the surgery.The brain tissues were collected 2hafter the behavioral tests.The expressions of PV andtwo essential subunits of NOX2,i.e.gp91 phox and p22 phoxin the cortex and hippocampus tissues were detected by the Western blot.Results In the open field test,no significant difference was observed in the total travel distance.Compared with groups A and B,the time spent in the center of the arena,the freezing time to cued and contextual fear conditioning,and the PV level were significantly decreased while the expressions of gp91 phox and p22 phox were significantly increased in group D（P〈0.05）.Compared with group C,the time spent in the center of the arena,the freezing time to cued and contextual fear conditioning,and the PV level were significantly increased while the expressions of gp91 phox and p22 phox were significantly decreased in group D（P〈0.05）.Conclusion The decreased expression of PV mediated by NOX2 activation in the brain may be involved in the sepsis associated encephalopathy.