Toll-Like Receptor 4 Mediates Lung Ischemia-Reperfusion Injury Akira Shimamoto, MD, PhD, Timothy H. Pohlman, MD, Shin Shomura, MD, Tomohito Tarukawa, MD, Motoshi Takao, MD, PhD, Hideto Shimpo, MD, PhD  The Annals of Thoracic Surgery  Volume 82, Issue 6, Pages 2017-2023 (December 2006) DOI: 10.1016/j.athoracsur.2006.06.079 Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions

Fig 1 Toll-like receptor 4 (TLR4) deficiency reduces lung ischemia-reperfusion injury. Lungs from either wild-type (WT) mice (open bars) or TLR4−/− (KO) mice (closed bars) were subjected to ischemia-reperfusion (IR) injury, as described in Methods. At the completion of lung ischemia-reperfusion injury, lung tissue was obtained to determine the following: (A) lung vascular permeability (values represent mean ± SE of 8 animals in each group; *p < 0.001 versus sham; †p = 0.001 versus WT); (B) tissue myeloperoxidase (MPO) activity as an indirect measure of neutrophil infiltration (values represent mean ± SE of 6 animals in each group; *p < 0.05 versus sham; †p = 0.006 versus WT); and (C) bronchoalveolar lavage (BAL) cell counts (values represent mean ± SE of 6 animals in each group; *p < 0.005 versus sham; †p = 0.00001 versus WT). The Annals of Thoracic Surgery 2006 82, 2017-2023DOI: (10.1016/j.athoracsur.2006.06.079) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions

Fig 2 The activity of c-Jun NH2-terminal kinase (JNK) during lung ischemia-reperfusion injury (LIRI) is diminished in Toll-like receptor 4 (TLR4) deficient mice. After LIRI, lung tissue from either wild-type mice (WT) or TLR4−/− mice (KO) were obtained and examined by Western immunoblotting analysis (A, B, C) for both phosphorylated and total amounts of mitogen-activated protein kinases (MAPKs): p38, JNK, and extracellular signal-regulated kinase (ERK). (D) Densitometry was used to quantify the ratio of phospho- to total-MAPK immunoreactivity for each sample from either WT mice (open bars) or KO mice (closed bars); the results are expressed as fold-increase of phospho-MAPK amount over total MAPK quantity. (Values represent mean ± SE of 4 animals in each group; *p < 0.005 versus sham; †p = 0.02 versus WT.) The Annals of Thoracic Surgery 2006 82, 2017-2023DOI: (10.1016/j.athoracsur.2006.06.079) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions

Fig 3 Lung ischemia-reperfusion injury (LIRI)–induced nuclear factor (NF)-κB and activator protein (AP)-1 nuclear translocations are blocked in Toll-like receptor 4 (TLR4) deficient mice. (A, B) Electrophoretic mobility shift assays were performed on nuclear proteins isolated from tissue samples obtained from lungs subjected to LIRI in either wild-type mice (WT) or TLR4−/− mice (KO). (C) Shifted band strength was quantified by densitometry for each sample from either WT mice (open bars) or KO mice (closed bars). (Values represent mean ± SE of 4 animals in each group; *p < 0.0005 versus sham; †p < 0.001 versus WT.) The Annals of Thoracic Surgery 2006 82, 2017-2023DOI: (10.1016/j.athoracsur.2006.06.079) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions

Fig 4 Absence of Toll-like receptor 4 (TLR4) signal transduction is associated with decreased inflammatory cytokine expression in bronchoalveolar lavage during lung ischemia-reperfusion injury. Enzyme-linked immunosorbent assays were performed, as described in Methods, on lung samples from either wild-type (WT) mice (open bars) or TLR4−/− (KO) mice (closed bars) for keratinocyte chemoattractant (KC [a murine functional homologue of interleukin-8]) and other selected chemokines and cytokines identified on the x-axis. (Values represent mean ± SE of 8 animals in each group; *p < 0.05 versus sham; †p < 0.05 versus WT.) (MCP = monocyte chemoattractant protein; MIP = macrophage inflammatory protein; TNF = tumor necrosis factor.) The Annals of Thoracic Surgery 2006 82, 2017-2023DOI: (10.1016/j.athoracsur.2006.06.079) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions