摘要
目的:探讨齐墩果酸(oleanolic acid,OA)预处理对大鼠肝脏缺血再灌注损伤(hepatic ischemic/reperfusion injury,HIRI)过程中IKK/I-κB/NF-κB信号转导通路的影响。方法:将128只SD大鼠随机分为假手术组(SH组)、缺血再灌注组(IR组)、0.5%羧甲基纤维素钠组(CM组)和齐墩果酸预处理组(OA组)。OA组以100 mg/kg的齐墩果酸混悬液,SH和IR组以相同容积的水,CM组以相同容积的0.5%CMC-Na分别每日灌胃1次,连续7天。第8天建立70%肝脏缺血模型,缺血60 min后再灌注。于术前、再灌注0、3、6 h取肝组织。用Western blot法测定肝脏细胞内IKK2,I-κBα及细胞核内NF-κB p65蛋白含量。结果:术前、0 h,各组胞浆未检测到IKK2,核内仅检测到极少量NF-κB,各组I-κBα蛋白量之间没有统计学差异。3、6 h时,SH组胞浆IKK2和核内NF-κB的蛋白含量均分别明显低于其余3组(P<0.05);此时OA组该两个蛋白含量分别明显低于CM组和IR组(P<0.05)。3、6 h时,SH组I-κBα的蛋白含量均分别明显高于其余3组(P<0.05),OA组此值分别明显高于CM组和IR组(P<0.05),CM组和IR组各时点之间的细胞内IKK2,I-κBα及细胞核内NF-κB p65蛋白量均无统计学差异(P>0.05)。结论:HIRI能促进胞浆内IKK2蛋白的表达,使I-κB磷酸化水解,NF-κB活化进入细胞核内介导炎症反应,损伤肝细胞。缺血前使用OA可抑制IKK/I-κB/NF-κB信号传导通路的激活,这可能是OA预处理减轻HIRI的机制之一。
Objective：To investigate the influence of oleanolic acid（OA） pretreatment to rat’s IKK/I-κB/NF-κB signaling pathway around its hepatic ischemic/reperfusion injury（HIRI）.Methods：One hundred and twenty eight male Sprague-Dawley（SD） rats were randomly divided into sham group（SH）,ischemic/reperfusion group（IR）,0.5% sodium carboxymethycellulose（CMC-Na） group（CM） and OA＋0.5% CMC-Na group（OA）.Before the operation,the rats of each group received intragastric administration of corresponding solution once a day for seven days（OA group with 100 mg/kg of OA dissolved in 0.5% CMC-Na,SH group and IR group with water of the same volume,CM group with 0.5% CMC-Na of the same volume）.At the 8th day,rats were suffered from segmental（70%） hepatic ischemia for 60 min and then followed with different periods of reperfusion.The hepatic tissue were obtained at 0 h,3 h,and 6 h after the reperfusion.The expression of IKK2 and I-κBα in the cytoplasm and NF-κB p65 in the nucleus were evaluated by the method of Western blotting.Results：There was no IKK2 expression in the cytoplasm,and only few of NF-κB p65 was detected in the nucleus before operation or 0h after reperfusion in each group.Meanwhile,the volume of I-κBα detected in the cytoplasm has no significant difference among four groups at the same point of time.The expression of IKK2 in the cytoplasm and NF-κB p65 in the nucleus in the SH group was much lower than those in other three groups（P 〈 0.05）,while those proteins detected in OA group is less than those in CM group and IR group（P 〈 0.05）at 3h or 6 h after reperfusion.At these two points of time,the expression of I-κBα in SH group was higher than that in the other three groups（P 〈 0.05）,and this protein detected in OA group is more than that in CM group and IR group（P 〈 0.05）.The expressions of IKK2 and I-κBα in the cytoplasm and NF-κB p65 in nucleus between CM group and IR group had no significant difference at each point of time（P 〉 0.05）.Conclusion：HIRI would increase the expression of IKK2 in the cytoplasm,leading to the phosphorylation of I-κB,activating NF-κB and making it to translocate into the nucleus,and then the activated NF-κB which could mediate inflammatory response eventually caused damage of liver cells.The pretreatment of OA can inhibit the activating of the signaling pathway of IKK/I-κB/NF-κB,which may be one of the mechanisms for OA alleviating HIRI.
出处
《南京医科大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第5期697-701,共5页
Journal of Nanjing Medical University(Natural Sciences)
基金
国家自然科学基金资助(30672523)
