米诺环素对大鼠肝缺血再灌注损伤的保护作用

Protective effect of minocycline on hepatic ischemiareperfusion injury in rats

目的:探讨米诺环素对大鼠肝缺血再灌注损伤的保护作用及其分子机制。方法:54只雄性SD大鼠随机分成假手术对照组、缺血再灌注组和米诺环素组,每组18只。米诺环素组在缺血再灌注模型的基础上,自手术前36 h开始给予米诺环素灌胃给药(45 mg/kg),以后每12 h给药1次(22.5 mg/kg)。再灌注后2,6,24 h检测血清谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate aminotransferase,AST)、乳酸脱氢酶(lactate dehydrogenase,L D H)水平;肝组织行H E染色,观察病理组织学改变并计算评分(根据S u z u k i标准);肝组织匀浆检测丙二醛(malondialdehyde,MDA)、髓过氧化物酶(myeloperoxidase,MPO)水平;real-time PCR检测肝组织肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)、白介素1β(interleukin-1 beta,IL-1β)m RNA的表达;Western印迹测定Dickkopf-1(DKK-1)和β-连环蛋白(β-catenin)的表达。结果:再灌注2,6,24 h后,与缺血再灌注组比较,米诺环素处理组血清ALT,AST,LDH水平,以及肝组织病理学半定量评分、肝组织中TNF-α和IL-1βm RNA水平的表达均降低(均P<0.05);氧化损伤指标MDA和MPO在肝组织中的含量减少(均P<0.05);米诺环素组DKK-1的蛋白表达下调(P<0.05),β-catenin蛋白表达上调(P<0.05)。结论:米诺环素可减轻缺血再灌注对肝的损伤,其机制可能是通过激活Wnt/β-catenin信号通路而减轻肝氧化应激,并抑制促炎性细胞因子的释放。

Objective: To explore the protective effect of minocycline on hepatic ischemia-reperfusion injury (IRI) in rats and the underlying mechanisms. Methods: A total of 54 male Sprague-Dawley rats were randomly divided into 3 groups: the sham-operated group (control group), the ischemic–reperfusion (IR group), and the minocycline preconditioning group (n=18 per group). The rats in the minocycline preconditioning group were given minocycline (45 mg/kg) by gastric irrigation at 36 h before operation and then were subsequently administered with minocycline (22.5 mg/kg) at every 12 h. hTe rats were sacriifcedat 2, 6, 24 h after reperfusion. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured. HE staining of liver tissues was performed to detect the histological changes, and the degree of liver IRI according to Suzuki score were calculated. hTe levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were determined by spectrophotometer; the mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) in the liver were measured by real-time PCR; Dickkopf-1 (DKK-1) and beta-catenin (β-catenin) protein expression in the liver were detected by Western blot. Results: Atfer 2, 6, 24 h reperfusion, compared with the IR group, the liver function (ALT, AST and LDH) in the minocycline group was signiifcantly improved (allP<0.05); the Suzuki’s scores and the levels of hepatic TNF-α and IL-1β mRNA were signiifcantly decreased (allP<0. 05); the MDA and MPO levels the liver were decreased (bothP<0.05); the protein expression of hepatic DKK-1 was decreased (P<0.05), while the protein expression of β-catenin was increased (P<0.05). Conclusion: Minocycline can alleviate the ischemic-reperfusion injury mainly through reducing oxidative stress and inhibiting the release of pro-inlfammatory cytokines depends on the activation of the Wnt/β-catenin signaling pathway in the liver.