Abstract: Objective To investigate the expression of toll-like receptors in astrocytes administrated with lipopolysaccharide (LPS). Methods LPS was administrated to rat astrocytes for 24h, and the expression of toll-like receptors and NF-κB p65 in astrocytes was detected by immunofluorescence and western blotting. At the same time, the effect of inhibitor of NF-κB signal pathway was investigated. Results Astrocytes expressed both cell surface and intracellular TLR3, low-level TLR4 in normal circumstance. LPS up-regulated the expression of TLR4 and NF-κB p65 in astrocytes in a concentration-dependent manner, while the expression of TLR3 kept constant. Pretreatment with SN90 (inhibitor of NF-κB) could block the increase of the expression of TLR4. Conclusion The expression of toll-like receptors in astrocytes was not homogeneous but rather tailored environmental signal. The molecular mechanism of the changes may be related to the expression of NF-κB p65.

Key words: lipopolysaccharide, astrocyte, TLR3, TLR4, NF-κB p65.