Liu Anding, Fang Haoshu, Wei Weiwei, Dirsch Olaf, Dahmen Uta
1Experimental Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. 2Experimental Transplantation Surgery, Department of General, Visceral and Vascular Surgery, University Hospital of Jena, Friedrich-Schiller-University Jena, Jena, Germany. 3Department of Pathophysiology, Anhui Medical University, Hefei, China. 4Institute for Pathology, University Hospital of Jena, Friedrich-Schiller-University Jena, Jena, Germany.
Crit Care Med. 2014 Dec;42(12):e762-71. doi: 10.1097/CCM.0000000000000659.
Ischemic preconditioning exerts a protective effect in hepatic ischemia/reperfusion injury. The exact mechanism of ischemic preconditioning action remains largely unknown. Recent studies suggest that autophagy plays an important role in protecting against ischemia/reperfusion injury. However, the role of autophagy in ischemic preconditioning-afforded protection and its regulatory mechanisms in liver ischemia/reperfusion injury remain poorly understood. This study was designed to determine whether ischemic preconditioning could protect against liver ischemia/reperfusion injury via heme oxygenase-1-mediated autophagy.
Laboratory investigation.
University animal research laboratory.
Male inbred Lewis rats and C57BL/6 mice.
Ischemic preconditioning was produced by 10 minutes of ischemia followed by 10 minutes of reperfusion prior to 60 minutes of ischemia. In a rat model of hepatic ischemia/reperfusion injury, rats were pretreated with wortmannin or rapamycin to evaluate the contribution of autophagy to the protective effects of ischemic preconditioning. Heme oxygenase-1 was inhibited with tin protoporphyrin IX. In a mouse model of hepatic ischemia/reperfusion injury, autophagy or heme oxygenase-1 was inhibited with vacuolar protein sorting 34 small interfering RNA or heme oxygenase-1 small interfering RNA, respectively.
Ischemic preconditioning ameliorated liver ischemia/reperfusion injury, as indicated by lower serum aminotransferase levels, lower hepatic inflammatory cytokines, and less severe ischemia/reperfusion-associated histopathologic changes. Ischemic preconditioning treatment induced autophagy activation, as indicated by an increase of LC3-II, degradation of p62, and accumulation of autophagic vacuoles in response to ischemia/reperfusion injury. When ischemic preconditioning-induced autophagy was inhibited with wortmannin in rats or vacuolar protein sorting 34-specific small interfering RNA in mice, liver ischemia/reperfusion injury was worsened, whereas rapamycin treatment increased autophagy and mimicked the protective effects of ischemic preconditioning. Furthermore, ischemic preconditioning increased heme oxygenase-1 expression. The inhibition of heme oxygenase-1 with tin protoporphyrin IX in rats or heme oxygenase-1-specific small interfering RNA in mice decreased ischemic preconditioning-induced autophagy and diminished the protective effects of ischemic preconditioning against ischemia/reperfusion injury.
Ischemic preconditioning protects against liver ischemia/reperfusion injury, at least in part, via heme oxygenase-1-mediated autophagy.
缺血预处理对肝缺血/再灌注损伤具有保护作用。缺血预处理作用的确切机制在很大程度上仍不清楚。最近的研究表明，自噬在预防缺血/再灌注损伤中起重要作用。然而，自噬在缺血预处理所提供的保护中的作用及其在肝缺血/再灌注损伤中的调节机制仍知之甚少。本研究旨在确定缺血预处理是否可通过血红素加氧酶-1介导的自噬来预防肝缺血/再灌注损伤。
实验室研究。
大学动物研究实验室。
雄性近交系Lewis大鼠和C57BL/6小鼠。
在60分钟缺血之前，通过10分钟缺血然后10分钟再灌注产生缺血预处理。在肝缺血/再灌注损伤大鼠模型中，用渥曼青霉素或雷帕霉素预处理大鼠，以评估自噬对缺血预处理保护作用的贡献。用锡原卟啉IX抑制血红素加氧酶-1。在肝缺血/再灌注损伤小鼠模型中，分别用液泡蛋白分选34小干扰RNA或血红素加氧酶-1小干扰RNA抑制自噬或血红素加氧酶-1。
缺血预处理改善了肝缺血/再灌注损伤，表现为血清转氨酶水平降低、肝脏炎性细胞因子水平降低以及缺血/再灌注相关组织病理学变化减轻。缺血预处理诱导了自噬激活，表现为LC3-II增加、p62降解以及对缺血/再灌注损伤的自噬空泡积累。当用渥曼青霉素在大鼠中或液泡蛋白分选34特异性小干扰RNA在小鼠中抑制缺血预处理诱导的自噬时，肝缺血/再灌注损伤加重，而雷帕霉素治疗增加了自噬并模拟了缺血预处理的保护作用。此外，缺血预处理增加了血红素加氧酶-1的表达。用锡原卟啉IX在大鼠中或血红素加氧酶-1特异性小干扰RNA在小鼠中抑制血红素加氧酶-1可减少缺血预处理诱导的自噬，并减弱缺血预处理对缺血/再灌注损伤的保护作用。
缺血预处理至少部分通过血红素加氧酶-1介导的自噬来预防肝缺血/再灌注损伤。
