摘要
目的 评价间歇性禁食对老龄大鼠术后认知功能的影响及Janus激酶2(JAK2)/信号转导和转录激活因子3(STAT3)信号通路在其中的作用.方法 SPF级健康雄性SD大鼠80只,20月龄,体质量600～650 g,采用随机数字表法分为4组(n=20):对照组(C组)、术后认知功能障碍(POCD)组(P组)、间歇性禁食+POCD组(IF+P组)和间歇性禁食+JAK2/STAT3信号通路激动剂C-A1+POCD组(IF+A+P组).IF+P组和IF+A+P组接受为期4周的间歇性禁食:禁食24 h而后自由进食24 h,全程不限制水的摄入;IF+A+P组大鼠于间歇性禁食期间每天腹腔注射C-A1 100μg/kg.P组、IF+P组和IF+A+P组大鼠在七氟烷麻醉下行剖腹探查术制备POCD模型.术后3 d时行旷场实验评估大鼠自主运动功能,术后3～7 d时行Morris水迷宫实验评估大鼠认知功能.水迷宫实验结束后处死大鼠取海马CA1区,采用Western blot法测定JAK2、磷酸化JAK2(p-JAK2)、STAT3、磷酸化STAT3(p-STAT3)的表达,采用ELISA法检测1L-6、IL-1β和TNF-α的含量,HE染色观察海马CA1区病理学结果.结果 4组旷场实验运动速度、路程以及旷场中心停留时间比较差异无统计学意义(P＞0.05).与C组比较,P组逃避潜伏期延长,穿越原平台位置次数减少,海马CA1区p-JAK2/JAK2比值和p-STAT3/STAT3比值、IL-6、IL-1β和TNF-α含量升高(P＜0.05),海马CA1区出现病理学损伤.与P组比较,IF+P组逃避潜伏期缩短,穿越原平台位置次数增加,海马CA1区p-JAK2/JAK2比值和p-STAT3/STAT3比值、IL-6、IL-1β和TNF-α含量降低(P＜0.05),海马CA1区病理学损伤减轻.与IF+P组比较,IF+A+P组逃避潜伏期延长,穿越原平台位置次数减少,海马CA1区p-JAK2/JAK2比值和p-STAT3/STAT3比值、IL-6、IL-1β和TNF-α含量升高(P＜0.05),海马CA1区病理学损伤加重.结论 间歇性禁食可改善老龄大鼠术后认知功能,其机制可能与抑制JAK2/STAT3信号通路激活,减轻海马CA1区神经炎症反应有关.
Abstract
Objective To evaluate the effect of intermittent fasting on postoperative cognitive func-tion in aged rats and the role of Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)signaling pathway in it.Methods Eighty SPF healthy male Sprague-Dawley rats,aged 20 months,weighing 600-650 g,were divided into 4 groups(n=20 each)using a random number table meth-od:control group(group C),postoperative cognitive dysfuction(POCD)group(group P),intermittent fasting+POCD group(group IF+P),and intermittent fasting+JAK2/STAT3 signaling pathway agonist C-A1+POCD group(group IF+A+P).IF+P group and IF+A+P group underwent a 4-week intermittent fast-ing procedure:fasting for 24 h followed by free eating for 24 h,without limiting water intake throughout the entire process,in addition C-A1 100 μg/kg was intraperitoneally injected daily during intermittent fasting in IF+A+P group.Rats underwent exploratory laparotomy under sevoflurane anesthesia to prepare POCD mod-els in P group,IF+P group and IF+A+P group.Three days after surgery,open field tests were conducted to evaluate the autonomous motor function of rats,and Morris water maze tests were conducted to evaluate the cognitive function of rats on 3-7 days after surgery.After the Morris water maze tests,the rats were sacri-ficed and the hippocampal CA1 area was removed for determination of the expression of JAK2,phosphoryla-ted JAK2(p-JAK2),STAT3,and phosphorylated STAT3(p-STAT3)(by Western blot)and contents of interleukin-6(IL-6),IL-1β and tumor necrosis factor-alpha(TNF-α)(by enzyme-linked immunosorbent assay)and for microscopic examination of pathological changes of hippocampal CA1 region(using HE stai-ning).Results There was no statistically significant difference in the speed,distance and duration of stay at the center of the open field test among the four groups(P＞0.05).Compared with group C,the escape la-tency was significantly prolonged,the number of crossing the original platform was reduced,and the p-JAK2/JAK2 ratio,p-STAT3/STAT3 ratio and contents of IL-6,IL-1β and TNF-α in the hippocampal CA1 region were increased(P＜0.05),and the pathological damage occurred in the hippocampal CA1 region in group P.Compared with P group,the escape latency was significantly shortened,the number of crossing the original platform was increased,and the p-JAK2/JAK2 ratio,p-STAT3/STAT3 ratio and contents of IL-6,IL-1β and TNF-α in the hippocampal CA1 region were decreased(P＜0.05),and the pathological damage in the hippocampal CA1 area was significantly alleviated in IF+P group.Compared with IF+P group,the es-cape latency was significantly prolonged,the number of crossing the original platform was reduced,and the p-JAK2/JAK2 ratio,p-STAT3/STAT3 ratio and contents of IL-6,IL-1β and TNF-α in the hippocampal CA1 region were increased(P＜0.05),and the pathological damage in the hippocampal CA1 area was aggravated in group IF+A+P.Conclusions Intermittent fasting can improve postoperative cognitive function in aged rats,and the mechanism may be related to inhibiting the JAK2/STAT3 signaling pathway and reducing the neuroinflammatory responses in the hippocampal CA1 region.
基金项目
国家自然科学基金面上项目(82071220)
国家自然科学基金面上项目(82371205)
天津市医学重点学科(专科)建设项目(TJYXZDXK-072C)
天津市医学重点学科专项(TJWJ2023XK019)
NETL
NSTL
万方数据