海马亲环素D在大鼠脓毒症相关性脑病中的作用

Role of hippocampal cyclophilin D in sepsis-associated encephalopathy in rats

目的 探讨海马亲环素D（CypD）在大鼠脓毒症相关性脑病中的作用.方法 成年雄性SD大鼠36只,3～4月龄,体重300～400 g,采用随机数字表法分为3组（n=12）：假手术组（Sham组）、脓毒症组（S组）、脓毒症＋亲环素D抑制剂环孢素A组（CsA组）.采用盲肠结扎穿孔法建立脓毒症模型,CsA组于造模前30 min腹腔注射环孢索A 6 mg/kg.于造模后第4天行Morris水迷宫实验.行为学测试后处死大鼠,取海马组织,采用Western blot法检测海马细胞色素c（Cyt c）、CypD、caspase-3、脑源性神经营养因子（BDNF）、磷酸化蛋白激酶A（p-PKA）和磷酸化环磷腺苷效应元件结合蛋白（p-CREB）的表达.结果 与Sham组比较,S组和CsA组逃避潜伏期延长,空间探索时间缩短,海马Cyt c、CypD、caspase-3、p-PKA和p-CREB表达上调,BDNF表达下调（P＜0.05）;与S组比较,CsA组逃避潜伏期缩短,空间探索时间延长,海马Cyt c、CypD、caspase-3、p-PKA和p-CREB表达下调,BDNF表达上调（P＜0.05）.结论 海马CypD可能参与了大鼠脓毒症相关性脑病的病理生理机制,其下游机制可能与促进PKA/CREB信号通路激活有关.

Objective To investigate the role of hippocampal cyclophilin D （CypD） in sepsis-associated encephalopathy in rats.Methods A total of 36 adult male Sprague-Dawley rats,aged 3-4 months,weighing 300-400 g,were randomly divided into 3 groups （n =12 each） using a random number table：sham operation group （Sham group）,sepsis group （S group）,and sepsis ＋ CypD inhibitor cyclosporin A group （CsA group）.Sepsis was induced by cecal ligation and puncture （CLP）.Cyclosporin A 6 mg/kg was injected intraperitoneally at 30 min before CLP in group CsA.All the animals underwent Morris water maze test on 4th day after CLP.The animals were sacrificed after the test,and the hippocampus was isolated for determination of the expression of cytochrome c （Cyt c）,CypD,caspase-3,brain-derived neurotrophic factor （BDNF）,phosphorylated protein kinase A （p-PKA）,and phosphorylated cyclic adenosine monophosphate response element-binding protein （p-CREB）.Results Compared with group Sham,the escape latency was significantly prolonged,the space exploration time was shortened,the expression of Cyt c,CypD,caspase-3,p-PKA and p-CREB was up-regulated,and the expression of BDNF was down-regulated in S and CsA groups （P〈0.05）.Compared with group S,the escape latency was significantly shortened,the space exploration time was prolonged,the expression of Cyt c,CypD,caspase-3,p-PKA and p-CREB was down-regulated,and the expression of BDNF was up-regulated in group CsA （P〈0.05）.Conclusion Hippocampal CypD may be involved in the pathophysiological mechanism of sepsis-associated encephalopathy,and the downstream mechanism is probably related to promotion of activation of PKA/CREB signaling pathway in rats.