Limb Remote Ischemic Postconditioning Reduces Ischemia-Reperfusion Injury by Inhibiting NADPH Oxidase Activation and MyD88-TRAF6-P38MAP-Kinase Pathway of Neutrophils
Limb Remote Ischemic Postconditioning Reduces Ischemia-Reperfusion Injury by Inhibiting NADPH Oxidase Activation and MyD88-TRAF6-P38MAP-Kinase Pathway of Neutrophils
复制标题
肢体远程缺血后处理通过抑制中性粒细胞 NADPH 氧化酶激活和 MyD88-TRAF6-P38MAP-激酶途径减少缺血再灌注损伤
DOI：
10.3390/ijms17121971
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发表时间：
2016-12-01
影响因子：
5.6
通讯作者：
Kou, Junping
中科院分区：
文献类型：
--
作者：
Chen, Gangling;Ye, Xinyi;Kou, Junping
肢体远端缺血后处理（Limb remote ischemic postconditioning，LRIP）已被证实可减轻缺血再灌注损伤，但其机制尚不清楚。本研究从中性粒细胞的烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶和髓样分化因子88（MyD 88）-肿瘤坏死因子（TNF）受体相关因子6（TRAF 6）-P38通路阐明了LRIP的作用机制。本研究采用大鼠大脑中动脉阻塞（MCAO）模型。采用MCAO 1.5h再灌注24 h的方法造成缺血再灌注损伤。分别于再灌注0、1、3 h行左股动脉LRIP术。行为学测试，包括姿势反射测试、触须诱发前肢放置测试和悬尾测试，表明再灌注0 h操作LRIP可显著改善这些行为学评分。病理学检查、脑梗死面积、髓过氧化物酶（MPO）活性检测结果显示，再灌注0 h LRIP可明显改善病理学评分，减少脑梗死面积，降低脑组织MPO活性，增加左腿MPO活性。应用中性粒细胞计数、免疫荧光和实时荧光PCR技术，我们发现再灌注0 h的LRIP可降低外周血中性粒细胞计数，下调外周血和大鼠脑内中性粒细胞的活化。Western blot结果显示，LRIP可下调中性粒细胞MyD 88、TRAF 6、p38丝裂原活化蛋白激酶（p38-MAPK）和p47 phox（Ser 304和Ser 345）的磷酸化水平。我们的研究表明，LRIP抑制大鼠脑和外周血中中性粒细胞的数量和活化与MyD 88/TRAF 6/p38-MAPK通路下调中性粒细胞中NADPH氧化酶的活化有关。
Limb remote ischemic postconditioning (LRIP) has been confirmed to reduce the ischemia-reperfusion injury but its mechanisms are still not clear. This study clarified the mechanism of LRIP based on the nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase and Myeloid differentiation factor 88 (MyD88)-Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6)-P38 pathway of neutrophils. Rat middle cerebral artery occlusion (MCAO) model was used in this study. Ischemia-reperfusion injury was carried out by MCAO 1.5 h followed by 24 h reperfusion. LRIP operation was performed to the left femoral artery at 0, 1 or 3 h after reperfusion. Behavioral testing, including postural reflex test, vibrissae-elicited forelimb placing test and tail hang test, showed that LRIP operated at 0 h of reperfusion could significantly ameliorate these behavioral scores. Pathological examinations, infarct size, Myeloperoxidase (MPO) activity showed that LRIP operated at 0 h of reperfusion could significantly ameliorate the pathological scores, reduce the infarct size and MPO activity in the brain and increase the MPO activity in the left leg. By using Neutrophil counting, immunofluorescence and real-time PCR techniques, we found that LRIP operated at 0 h of reperfusion could reduce neutrophil counts in the peripheral blood and downregulate the activation of neutrophil in the peripheral blood and rat brain. Western blots revealed that MyD88, TRAF6, p38 mitogen-activated protein kinase (p38-MAPK) in neutrophils and the phosphorylation of p47phox (Ser 304 and Ser 345) in neutrophil could be downregulated by LRIP. Our study suggests that LRIP inhibits the number and activation of neutrophils in the rat brain and peripheral blood linked to down-regulating the activation of NADPH oxidase in neutrophils by MyD88/TRAF6/p38-MAPK pathway.