OBJECTIVE: To assess the effect of lipopolysaccharides (LPS) on the expression of CD14 and TLR4 in rat Kupffer cells (KCs).
METHODS: In rat KCs induced by LPS, the changes of CD14 and TLR4 expression were measured by RT-PCR and immunohistochemistry, and the expressions of TNF-αmRNA, IL-6mRNA or the concentrations of TNF-α, IL-6 were estimated by in situ hybridization, radioimmunoassay, and others.
RESULTS: The expressions of CD14 and TLR4 in KCs induced by LPS were markedly increased in a dose-dependent manner (10 mg/L-1 μg/L) or in a time-dependent manner (0.5 h-24 h), with the peaked expression of CD14 at 3-6 hours. The expressions of CD14 and TLR4 in KCs stimulated by the active mediators from KCs which had been exposed to LPS for 1 hour were obviously increased.
CONCLUSIONS: There is a close relationship between LPS or the active mediators from KCs induced by LPS and the expressions of CD14, TLR4. It is implied that the increase of TLR4, CD14 expression may be induced by LPS within 1-3 hours, and further increase of TLR4, CD14 expression may be correlated with the cytokines produced by KCs.