The Role of CD14 and Toll-Like Receptor 4 of Kupffer Cells in Hepatic Ischemia-Reperfusion Injury in Rats

Objective. The objective of this study was to study the role of CD14 and Toll-like receptor 4 (TLR4) in Kupffer cells (KCs) on ischemia reperfusion injury (IRI) in rat liver grafts. Methods. Isolated KCs were obtained from control, IRI, and IRI plus anti-CD14 antibody groups. We measured messenger RNA (mRNA) and protein expression of the lipopolysaccharide receptor CD14 and TLR4, nuclear factor kappa B (NF-kappa beta) activity, and TNF-alpha levels. Results. mRNA and protein expressions of CD14 and TLR4 were significantly higher in the IRI than in the control group, as were protein expressions of CD14 and TLR4 by flow cytometry and by Western blots. NF-kappa beta activity and tumor necrosis factor-alpha level in the IRI group were significantly higher than in the control group (3.17 +/- 0.21 and 0.28 +/- 0.03 vs 654.2 +/- 3.6 pg/mL and 147.4 +/- 1.1 pg/mL; t value = 4.11 and 4.29 for each; P < .01). Compared with the IRI group they were greatly decreased after anti-CD14 antibody treatment: 2.14 +/- 0.17 vs 3.17 +/- 0.21, 298.7 +/- 1.8 pg/mL vs 654.2 +/- 3.6 pg/mL (t value = 2.52 and 2.92 for each; P < .05). They were still significantly higher than the control group (t values of 3.01 and 3.27 for each; P < .01). Conclusion. IRI up-regulated CD14 and TLR4 gene expression in KCs, and subsequently activated NF-kappa beta to produce cytokines.