Maresin 1对肝缺血再灌注损伤的影响及机制研究

Effect of Maresin 1 on hepatic ischemia-reperfusion injury and its mechanism

目的 探讨Maresin 1(MaR1)对肝缺血再灌注损伤的影响及机制。方法 将24只Wistar大鼠采用随机数字表法分为假手术组(Sham组)、肝缺血再灌注损伤组(I/R组)、MaR1治疗组(I/R+MaR1组)、抗磷脂酰肌醇-3激酶(PI3K)抑制剂LY294002组(I/R+MaR1+LY294002组),每组6只。I/R组、I/R+MaR1组及I/R+MaR1+LY294002组大鼠通过阻断肝左叶及中叶血流60 min,再灌注6 h建立肝缺血再灌注损伤模型。Sham组仅开腹和关腹,不阻断血流,I/R+MaR1组在肝缺血再灌注前1 h腹腔注射4 mg/kg MaR1,I/R+MaR1+LY294002组在肝缺血再灌注前30 min腹腔注射LY294002 0.5 mg/kg,其余处理同I/R+MAR1组。检测各组小鼠肝组织病理学改变,血肝功能、炎性反应和氧化应激反应的指标。Western blot法检测肝组织磷酸化磷脂酰肌醇-3激酶(p-PI3K)、磷酸化蛋白激酶B(p-Akt)、转录因子NF-E2相关因子2(Nrf2)、血红素氧合酶-1(HO-1)蛋白表达。结果 与Sham组比较,I/R组肝损伤明显,而I/R+MaR1组肝损伤明显减轻。与Sham组比较,I/R组血清中ALT、AST、乳酸脱氢酶(LDH)、TNF-α、IL-1β、IL-6、IL-10水平均升高,肝组织中丙二醛(MDA)水平升高,而超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽(GSH)水平均降低(均P<0.05)。与I/R组比较,I/R+MaR1组血清中ALT、AST、LDH、TNF-α、IL-1β、IL-6水平均降低(均P<0.05),肝组织MDA水平均降低,而IL-10、SOD、CAT、GSH水平升高(均P<0.05)。与Sham组比较,I/R组p-PI3K、p-Akt、Nrf2、HO-1蛋白表达均升高(均P<0.05),而I/R+MaR1组p-PI3K、p-Akt、Nrf2、HO-1蛋白表达进一步增加(均P<0.05)。然而,上述MaR1的治疗作用被PI3K抑制剂LY294002逆转。结论 MaR1通过上调PI3K/Akt/Nrf2/HO-1通路抑制炎性反应及氧化应激反应,进而减轻肝缺血再灌注损伤。

Objective To investigate the effect of Maresin1(MaR1) on liver ischemia/reperfusion(I/R) injury and the underlying mechanisms. Methods Twenty-four Wistar rats were randomly divided into Sham, I/R, I/R + MaR1 and I/R +MaR1 + LY294002 groups. Liver I/R injury model was established in I/R, I/R + MaR1 and I/R + MaR1 + LY294002 groups by blocking the left lobe and middle lobe blood flow for 60 min and reperfusion for 6 h. The abdomen was opened and closed without blocking blood flow in the sham group. I/R+MaR1 group was intraperitoneally injected with 4 mg/kg MaR1 1 h before hepatic I/R. I/R+MaR1+ LY294002 group was intraperitoneally injected with LY294002(0.5 mg/kg) 30 min before liver I/R,and the other treatments were the same as the MaR1 group. Hepatic histopathologic changes, function, inflammatory response and oxidative stress response was detected. The expression of relevant proteins were evaluated by Western blot.Results Compared with Sham group, I/R induced marked hepatic histological injury, which were less pronounced in I/R+MaR1 group. Compared with sham group, the levels of ALT, AST, LDH, TNF-α, IL-1β, IL-6 and IL-10 in serum were increased in the I/R group, and the level of MDA in liver tissue was increased, while the levels of SOD, CAT and GSH were decreased in the I/R group(all P<0.05). Compared with I/R group, the levels of ALT, AST, LDH, TNF-α, IL-1β and IL-6 in serum were decreased(all P<0.05), and the level of MDA in liver tissue was decreased, while the levels of IL-10, SOD, CAT and GSH were increased(all P<0.05). Compared with Sham group, the expression of p-PI3K, p-Akt, Nrf2, HO-1 were increased in I/R group, MaR1 treatment further increased the expression of p-PI3K, p-Akt, Nrf2 and HO-1(all P<0.05).However, these results were reversed by LY294002. Conclusion MaR1 alleviates liver I/R injury by inhibiting inflammatory response and oxidative stress response via up-regulating PI3K/Akt/Nrf2/HO-1 pathway.