Nrf2在富氢液减轻小鼠脓毒症氧化损伤中的作用

Effect of Nrf2 in hydrogen-rich saline to reduce the oxidative damage in septic mice

目的：探讨富氢液对小鼠脓毒症氧化损伤的影响及核因子E2相关因子2（Nrf2）的具体作用机制。方法：雄性C57BL/6野生型小鼠64只,体质量20-25 g,5周龄,采用随机数字表法,将其随机分为4组（n=16）：假手术组（A组）、盲肠结扎穿孔（CLP）组（B组）、CLP＋富氢液组（C组）、CLP＋富氢液＋全反式维甲酸（ATRA）组（D组）。采用CLP制备脓毒症模型。ATRA处理为CLP实验前1周,每天腹腔注射ATRA,10 mg/kg。各组于CLP或假手术后1、6 h时分别给予富氢液（HS）或生理盐水,5 mL/kg。每组取10只小鼠,观察CLP后7 d内生存情况。剩余24只动物,于手术后24 h下腔静脉采血,检测血清丙二醛（MDA）、抑制羟自由基（·OH）能力、超氧化物酶（SOD）和过氧化氢酶（CAT）水平,取肺检测Nrf2的表达。结果：与A组比较,B组小鼠7 d生存率降低,肺组织Nrf2表达增加,血清MDA含量增加,抑制·OH能力、SOD和CAT活性降低（P〈0.05）;与B组比较,C组小鼠7 d生存率升高（P〈0.05）,肺组织Nrf2表达进一步增加,血清MDA含量降低,抑制·OH能力、SOD和CAT活性增加（P〈0.05）;与C组比较,D组小鼠7 d生存率显著下降（P〈0.05）,肺组织Nrf2表达降低,血清MDA含量增加,抑制·OH能力、SOD和CAT活性降低（P〈0.05）。结论：富氢液对脓毒症氧化损伤具有治疗作用,可能与调节内源性抗氧化系统关键分子Nrf2有关。

Objective： To investigate the effects of Nrf2 in hydrogen-rich saline on sepsis in mice and the associated mechanism. Methods： Sixty four mice, aged 5 weeks, weighing 20-25 g were randomly divided into four groups （n=16 each）： sham operation group （group A）, cecal ligation and puncture （CLP） group （group B）, CLP ＋ hydrogen-rich saline group （group C）, CLP ＋ hydrogen-rich saline ＋ ATRA group （group D）. Severe sepsis was induced by CLP operation. ATRA was given i.p. daily at 10 mg/kg for 1 week before CLP. 5 mL/kg of hydrogen-rich saline was given at 1 and 6 h after CLP or sham operation, respectively. The survival rates of four groups （40 animals） were observed in 7 day. In additional 24 animals, blood was collected to test malondialdehyde（MDA）, inhibited ability of hydroxyl radical, activity of superoxide dismutase （SOD） and catalase （CAT） at 24 h after operation, then lung were collected to measure the Nrf2 protein expression. Results Compared with group A, survival rate of severe septic mice, the inhibited ability of hydroxyl radical, the activity of SOD and CAT were significantly decreased and the MDA was increased, the Nrf2 expression was increased in group B （P〈0.05）. Compared with group B, survival rate of severe septic mice, the inhibited ability of hydroxyl radical, SOD and CAT activities were significantly elevated and the MDA was decreased in serum of septic mice, the Nrf2 expression was further increased in group C（P〈0.05）. Compared with group C, survival rate of severe septic mice, the inhibited ability of hydroxyl radical, the activity of SOD and CAT were obviously decreased and the MDA was increased, the Nrf2 expression was reduced in group D （P〈0.05）. Conclusion： Hydrogen-rich saline can alleviate sever sepsis in mice via regulating Nrf2 protein expression.