DEX调控Nrf2/ARE通路对大鼠离体肺缺血-再灌注损伤的作用机制

Role mechanism of DEX on isolated rat lung ischemia-reperfusion injury by regulating Nrf2/ARE pathway

[目的]探究右美托咪定(dexmedetomidine,DEX)通过调控NF-E2相关因子2(NF-E2-related factor-2,Nrf2)/抗氧化反应元件(antioxidant response element,ARE)对大鼠离体肺缺血再灌注损伤(lung ischemia-reperfusion injury,LIRI)的作用机制。[方法]将60只大鼠分为对照组、LIRI组、LIRI+DEX低剂量、LIRI+DEX高剂量组(N=15)。构建离体LIRI模型(灌流15 min,停止60 min,再灌流75 min),在灌流液中加入DEX,剂量分别为5 nmol/L和10 nmol/L。检测各组大鼠湿/干比、肺组织损伤、炎性细胞因子、凋亡、氧化应激指标、Nrf2和ARE mRNA和蛋白水平。[结果]4组的上述指标比较差异显著(P<0.05)。LIRI组的W/D比值(8.14±0.62)、肺损伤评分为(7.74±0.48分)、凋亡细胞数目(23.45±1.95)、IL-1β(12.72±1.28 pg/mg)、TNF-α(57.32±4.07 pg/mg)、MDA(3.82±0.34 nmol/mg)水平显著高于对照组,SOD(42.78±4.38 U/mg)、Nrf2和ARE mRNA和蛋白水平显著低于对照组(P<0.05)。用DEX干预后,上述指标均显著缓解(P<0.05),并且LIRI+DEX高剂量组的W/D比值(6.25±0.55)、肺损伤评分(4.01±0.52分)、凋亡细胞数目(11.24±1.17)、IL-1β(8.57±0.89 pg/mg)、TNF-α(40.27±3.74 pg/mg)和MDA(2.95±0.28 nmol/mg)显著低于LIRI+DEX低剂量组,SOD(65.95±4.05 U/mg)、Nrf2和ARE mRNA和蛋白水平显著高于LIRI+DEX低剂量组(P<0.05)。[结论]DEX可通过提高Nrf2/ARE通路缓解氧化应激反应,抑制炎症和细胞凋亡,进而缓解LIRI。

[Objective] To explore the role mechanism of dexmedetomidine(DEX) on rat isolated lung ischemia–reperfusion injury(LIRI) through regulation of NF-E2-related factor-2(NF-E2-related factor-2,Nrf2)/antioxidant response element(ARE) pathway.[Method] Sixty rats were divided into control group,LIRI group,LIRI+DEX low-dose group,LIRI+DEX high-dose group(N=15).The in vitro LIRI model(perfusion for 15 minutes,stop for 60 minutes,and reperfusion for 75 minutes) was constructed.DEX was added to the perfusate at doses of 5 nmol/L and 10 nmol/L.The wet/dry ratio,lung tissue damage,inflammatory cytokines,apoptosis,oxidative stress indicators,Nrf2 and ARE mRNA and protein levels were detected in each group of rats.[Result] The above indicators of the four groups were significantly different(P<0.05).The W/D ratio(8.14±0.62),lung injury score(7.74±0.48 points),number of apoptotic cells(23.45±1.95),IL-1β(12.72±1.28 pg/mg),TNF-α(57.32±4.07 pg/mg),MDA(3.82±0.34 nmol/mg) levels in the LIRI group were significantly higher than those in the control group,SOD(42.78±4.38 U/mg),Nrf2 and ARE mRNA and protein levels were significantly lower than those in the control group(P<0.05).After the use of DEX intervention,the above indicators were significantly relieved(P<0.05).The W/D ratio(6.25±0.55),lung injury score(4.01±0.52 points),number of apoptotic cells(11.24±1.17),IL-1β(8.57±0.89 pg/mg),TNF-α(40.27±3.74 pg/mg) and MDA(2.95±0.28 nmol/mg) in the LIRI+DEX high dose group were significantly lower than those in the LIRI+DEX low-dose group,SOD(65.95±4.05 U/mg),Nrf2 and ARE mRNA and protein levels were significantly higher than those in the LIRI +DEX low-dose group(P<0.05).[Conclusion] DEX may alleviate the oxidative stress response,inhibit inflammation and cell apoptosis by increasing the Nrf2/ARE pathway,therebyalleviating LIRI.