TY - JOUR
T1 - Mechanisms of toll-like receptor 4 (TLR4)-mediated inflammation after cold ischemia/reperfusion in the heart
AU - Kaczorowski, David J.
AU - Nakao, Atsunori
AU - Vallabhaneni, Raghuveer
AU - Mollen, Kevin P.
AU - Sugimoto, Ryujiro
AU - Kohmoto, Junichi
AU - Zuckerbraun, Brian S.
AU - McCurry, Kenneth R.
AU - Billiar, Timothy R.
PY - 2009/5/27
Y1 - 2009/5/27
N2 - BACKGROUND.: Toll-Like Receptor 4 (TLR4) signaling mediates early inflammation after cold ischemia-reperfusion (I/R). We hypothesized that the TLR4 coreceptor CD14, the intracellular adaptor proteins myeloid differentiation factor 88 (MyD88) and TIR domain-containing-adaptor inducing IFNβ (TRIF) would be required for cold I/R induced inflammation. High mobility group box 1 (HMGB1) is a putative endogenous activator of TLR4. Therefore, we also assessed the contribution of HMGB1 in cold I/R induced inflammation. METHODS.: Syngeneic heart transplants were performed in mice deficient in CD14, MyD88, TRIF, or wild-type mice. In other experiments, anti-HMGB1 neutralizing antibody or control IgG was administered at reperfusion. Donor hearts were subjected to 2 hr of cold ischemia and retrieved after 3 hr of reperfusion. RESULTS.: After cold I/R, grafts revealed striking translocation of HMGB1 out of the nucleus in cardiac myocytes. Administration of an anti-HMGB1 neutralizing antibody resulted in reduced systemic interleukin (IL)-6, tumor necrosis factor alpha (TNFα), and intercellular adhesion molecule-1 (ICAM-1) messenger RNA (mRNA) levels (Pĝ‰Currency sign0.05). Compared with controls, CD14 knock-out (KO) mice exhibited significantly lower (Pĝ‰Currency sign0.05) systemic IL-6 and JE/monocyte chemotractant protein-1 levels after cold I/R. Intragraft TNFα and IL-1β mRNA levels were also significantly lower (Pĝ‰Currency sign0.05) in CD14 KO grafts. MyD88 KO mice exhibited significantly lower (P≥0.05) systemic IL-6 levels compared with control mice after cold I/R. Intragraft TNFα, IL-6, and ICAM-1 mRNA levels were also significantly lower (Pĝ‰Currency sign0.05) in MyD88 KO grafts. Significantly lower levels (Pĝ‰Currency sign0.05) of serum IL-6, monocyte chemotractant protein-1 as well as intragraft TNFβ, IL-6, IL-1β, and ICAM-1 were observed after cold I/R in TRIF deficient animals compared with controls. CONCLUSIONS.: CD14, MyD88, TRIF, and HMGB1 contribute to the inflammatory response that occurs after cold I/R. These results provide insight into the mechanisms of TLR4-mediated inflammation after cold I/R.
AB - BACKGROUND.: Toll-Like Receptor 4 (TLR4) signaling mediates early inflammation after cold ischemia-reperfusion (I/R). We hypothesized that the TLR4 coreceptor CD14, the intracellular adaptor proteins myeloid differentiation factor 88 (MyD88) and TIR domain-containing-adaptor inducing IFNβ (TRIF) would be required for cold I/R induced inflammation. High mobility group box 1 (HMGB1) is a putative endogenous activator of TLR4. Therefore, we also assessed the contribution of HMGB1 in cold I/R induced inflammation. METHODS.: Syngeneic heart transplants were performed in mice deficient in CD14, MyD88, TRIF, or wild-type mice. In other experiments, anti-HMGB1 neutralizing antibody or control IgG was administered at reperfusion. Donor hearts were subjected to 2 hr of cold ischemia and retrieved after 3 hr of reperfusion. RESULTS.: After cold I/R, grafts revealed striking translocation of HMGB1 out of the nucleus in cardiac myocytes. Administration of an anti-HMGB1 neutralizing antibody resulted in reduced systemic interleukin (IL)-6, tumor necrosis factor alpha (TNFα), and intercellular adhesion molecule-1 (ICAM-1) messenger RNA (mRNA) levels (Pĝ‰Currency sign0.05). Compared with controls, CD14 knock-out (KO) mice exhibited significantly lower (Pĝ‰Currency sign0.05) systemic IL-6 and JE/monocyte chemotractant protein-1 levels after cold I/R. Intragraft TNFα and IL-1β mRNA levels were also significantly lower (Pĝ‰Currency sign0.05) in CD14 KO grafts. MyD88 KO mice exhibited significantly lower (P≥0.05) systemic IL-6 levels compared with control mice after cold I/R. Intragraft TNFα, IL-6, and ICAM-1 mRNA levels were also significantly lower (Pĝ‰Currency sign0.05) in MyD88 KO grafts. Significantly lower levels (Pĝ‰Currency sign0.05) of serum IL-6, monocyte chemotractant protein-1 as well as intragraft TNFβ, IL-6, IL-1β, and ICAM-1 were observed after cold I/R in TRIF deficient animals compared with controls. CONCLUSIONS.: CD14, MyD88, TRIF, and HMGB1 contribute to the inflammatory response that occurs after cold I/R. These results provide insight into the mechanisms of TLR4-mediated inflammation after cold I/R.
KW - Cold storage
KW - Inflammation
KW - Ischemia-reperfusion
KW - Toll-like receptors
KW - Transplant
UR - http://www.scopus.com/inward/record.url?scp=67649613033&partnerID=8YFLogxK
U2 - 10.1097/TP.0b013e3181a36e5e
DO - 10.1097/TP.0b013e3181a36e5e
M3 - Article
C2 - 19461481
AN - SCOPUS:67649613033
SN - 0041-1337
VL - 87
SP - 1455
EP - 1463
JO - Transplantation
JF - Transplantation
IS - 10
ER -