Protectin DX对小鼠急性肝损伤的作用及相关机制

The protective effect of Protectin DX on acute liver injury induced by sepsis in mice and the underlying mechanism

目的 探讨炎症消退介质保护素DX(protectin DX,PDX)对脓毒症小鼠急性肝损伤的保护作用.方法 雄性C57BL/6小鼠30只,6~8周龄,体质量20~25 g,采用随机数字表法分为三组(均n=10):假手术组(Sham组)、脓毒症组(CLP组)和脓毒症+PDX干预组(CLP+PDX组).采用盲肠结扎穿孔(CLP)法制备脓毒症模型.于CLP后1 h时,CLP+PDX组腹腔注射PDX 1μg,Sham组和CLP组均腹腔注射等容量生理盐水.三组均在CLP后24 h时收集血清、肝组织,采用苏木精-伊红(HE)染色观察肝组织病理变化;采用全自动生化分析仪检测血清中谷丙转氨酶(ALT)和谷草转氨酶(AST)水平;ELISA检测血清中的TNF-α、IL-6、IFN-γ 和IL-10水平;Western blot检测肝组织中NF-κB活性;比色法检测肝组织中髓过氧化物酶(MPO)活性.应用SPSS 18.0软件,采用双侧t检验的统计学方法,对结果进行统计学分析.结果 与Sham组相比,CLP组HE染色显示:肝索排列紊乱,肝细胞肿胀坏死,炎性细胞浸润,可见淤血及出血,肝损伤评分显著增加;血清中的ALT、AST、TNF-α、IL-6、IFN-γ 和IL-10水平均明显升高(均P<0.05);肝组织中NF-κB、MPO活性显著增强(均P<0.05).CLP+PDX组与CLP组相比,肝组织结构形态损伤明显较轻;血清中的ALT、AST、TNF-α、IL-6和IFN-γ 水平均降低,抗炎因子IL-10水平升高,肝组织NF-κB、MPO活性明显被抑制(均P<0.05).结论 PDX可通过抑制NF-κB活性,进而减轻小鼠脓毒症导致的急性肝损伤.

Objective To explore the effect of Protectin DX(PDX) on acute liver injury(ALI) induced by sepsis in mice and the underlying mechanism. Methods Mice received cecum ligation and puncture(CLP) to induce sepsis-associated acute liver injury. Male C57BL/6 mice were randomly (random number) divided into 3 groups (n=10 each group): (1) sham group (S group), (2) CLP group and (3) CLP +PDX group (PDX group ). Mice in the PDX group were received PDX 1 μg (intraperitoneal injection). One hour after CLP operation, mice in the S and CLP groups were received equal amounts of saline. The serum and liver tissues were collected at 24 h after CLP. The histological changes of the liver were observed by HE staining. The ALT and AST levels in the serum were assessed by using the automatic biochemical analyzer. The levels of cytokines (TNF-α, IL-6, IFN-γ and IL-10) in the serum were quantified by ELISA. MPO activity in the liver tissues were assessed. Western blot was used to detect the expression of pNF-kB p65 and NF-kB p65 in liver tissues. Results Compared with the S group, HE staining in the CLP group showed disordered hepatic cords, hepatocyte swelling and necrosis, infiltrations of inflammatory cells, congestion and bleeding, and the score of liver injury was increased significantly (P<0.05). Levels of ALT, AST, TNF-α, IL-6, IFN-γ, and IL-10 were increased in the CLP group (P<0.05). The activities of NF-κB and MPO in the liver tissues were obviously enhanced (P<0.05). The levels of liver injury, cytokines (TNF-α, IL-6, IFN-γ), MPO and activities of NF-κB in the CLP+PDX group were significantly decreased when compared with those in the CLP group (P<0.05),while the concentration of IL-10 was significantly increased (P<0.05). Conclusions PDX can alleviate sepsis-induced acute liver injury through inhibiting NF-KB activity in the liver tissues.