title: Heme oxygenase-1 protects rat liver against warm ischemia/reperfusion injury via TLR2/TLR4-triggered signaling pathways.
abstract: OBJECTIVE
  To investigate the efficacy and molecular mechanisms of induced heme oxygenase (HO)-1 in protecting liver from warm ischemia/reperfusion (I/R) injury.
  
  
  METHODS
  Partial warm ischemia was produced in the left and middle hepatic lobes of SD rats for 75 min, followed by 6 h of reperfusion. Rats were treated with saline, cobalt protoporphyrin (CoPP) or zinc protoporphyrin (ZnPP) at 24 h prior to the ischemia insult. Blood and samples of ischemic lobes subjected to ischemia were collected at 6 h after reperfusion. Serum transaminases level, plasma lactate dehydrogenase and myeloperoxidase activity in liver were measured. Liver histological injury and inflammatory cell infiltration were evaluated by tissue section and liver immunohistochemical analysis. We used quantitative reverse transcription polymerase chain reaction to analyze liver expression of inflammatory cytokines and chemokines. The cell lysates were subjected to immunoprecipitation with anti-Toll-IL-1R-containing adaptor inducing interferon-β (TRIF) and anti-myeloid differentiation factor 88 (MyD88), and then the immunoprecipitates were analyzed by SDS-PAGE and immunoblotted with the indicated antibodies.
  
  
  RESULTS
  HO-1 protected livers from I/R injury, as evidenced by diminished liver enzymes and well-preserved tissue architecture. In comparison with ZnPP livers 6 h after surgery, CoPP treatment livers showed a significant increase inflammatory cell infiltration of lymphocytes, plasma cells, neutrophils and macrophages. The Toll-like receptor (TLR)-4 and TANK binding kinase 1 protein levels of rats treated with CoPP significantly reduced in TRIF-immunoprecipitated complex, as compared with ZnPP treatment. In addition, pretreatment with CoPP reduced the expression levels of TLR2, TLR4, IL-1R-associated kinase (IRAK)-1 and tumor necrosis factor receptor-associated factor 6 in MyD88-immunoprecipitated complex. The inflammatory cytokines and chemokines mRNA expression rapidly decreased in CoPP-pretreated liver, compared with the ZnPP-treated group. However, the expression of negative regulators Toll-interacting protein, suppressor of cytokine signaling-1, IRAK-M and Src homology 2 domain-containing inositol-5-phosphatase-1 in CoPP treatment rats were markedly up-regulated as compared with ZnPP-treated rats.
  
  
  CONCLUSIONS
  HO-1 protects liver against I/R injury by inhibiting TLR2/TLR4-triggered MyD88- and TRIF-dependent signaling pathways and increasing expression of negative regulators of TLR signaling in rats.
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Han-Fei
authors.initials: HF
authors.lastname: Huang
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Kun-Hua
authors.initials: KH
authors.lastname: Wang
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Zhang
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Wen-Xiang
authors.initials: WX
authors.lastname: Zhou
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Zhan-Bo
authors.initials: ZB
authors.lastname: Wang
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Wang-Gang
authors.initials: WG
authors.lastname: Xu
authors.affiliation: Han-Fei Huang, Zhong Zeng, Kun-Hua Wang, Hai-Yan Zhang, Shuai Wang, Wen-Xiang Zhou, Zhan-Bo Wang, Wang-Gang Xu, Jian Duan, Organ Transplantation Center, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Duan
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D000818:Animals; D019610:Cytoprotection; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D008297:Male; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D011524:Protoporphyrins / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology / Q000209:etiology / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects*; D051195:Toll-Like Receptor 2 / Q000187:drug effects* / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000187:drug effects* / Q000378:metabolism; D052096:Warm Ischemia / Q000009:adverse effects*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D004791:Enzyme Inhibitors; C507781:Myd88 protein, rat; D053594:Myeloid Differentiation Factor 88; D011524:Protoporphyrins; C523075:Ticam1 protein, rat; C495343:Tlr2 protein, rat; C495347:Tlr4 protein, rat; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; C017803:zinc protoporphyrin; C007095:cobaltiprotoporphyrin; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat
keywords: Heme oxygenase-1; Ischemia reperfusion injury; Liver; Myeloid differentiation factor 88; Toll-like receptor