Toll-Like Receptors in Hepatic Ischemia/Reperfusion and Transplantation

Figure 1

Role of TLR4 in hepatic I/R injury. Signaling through the pattern recognition receptor TLR4 mediates multiple inflammatory pathways following hepatic I/R. The activation of TLR4 signaling is dependent, in part, on circulating DAMPs. Downstream signaling events include the TRIF-dependent activation of IRF3, the production of Type I IFN, and upregulation of CXCL10. Additionally, TLR4 activation of IRF1 promotes release of the DAMP, HMGB1. Lastly, TLR4 activation is thought to suppress the cytoprotective HO-1 pathway.