Figure 5

Response of Toll-like receptor 4 (TLR4)-deficient mice to recombinant human high-mobility group box 1 (rhHMGB1) administration. (A) Pancreatic histopathological changes in wild-type (WT) and TLR4-deficient mice 48 h after the administration of a high dose of rhHMGB1. Representative H&E-stained micrographs (original magnification, ×200) from the (a) WT and (b) TLR4−/− groups. The pancreatic tissues in the wild-type group exhibited marked edema, infiltration of inflammatory cells, a mass of necrotic acinar cells and the disappearance of the normal lobe structure in the pancreas; there was a significant reduction in the TLR4-deficient group. (B-a) Histological scores of the pancreas and (b) serum amylase and lipase changes in the WT and TLR4−/− groups. (C) The activation of nuclear factor-κB (NF-κB) was assessed from the nuclear p65 [(a) western blot analysis] and its downstream, relative levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) [(b) ELISA] in the pancreatic tissue from the WT and TLR4−/− groups. *P<0.01 compared to the WT group. The relative levels of nuclear p65 protein compared to the control group are normalized to histone 3 (H3). The relative levels of TNF-α and IL-1β compared to the control group are normalized to the total protein concentration of each sample. Data are expressed as the means ± SD (n=6/group). Blots shown are from a representative experiment that was repeated 3 times with similar results (n=6/group). WT, WT mice given a high dose of rhHMGB1; TLR4−/−, TLR4-deficient mice administered a high dose of rhHMGB1.