[The change in Toll-like receptor 4 gene expression in skeleton of endotoxemia mice].

OBJECTIVE: To explore the changes in gene expression of bone in endotoxemia in mice. METHODS: Lipopolysaccharide (LPS) was injected intraperitoneally to reproduce an endotoxemia model in mice. Forty-eight mice were randomly divided into eight groups: normal group, 4, 6, 8, 12, 24, 48 and 72 hours after LPS injection groups, with 6 mice in each group. To evaluate endotoxemia whole blood was collected for leukocytic count, eye sockets blood was obtained for liver and renal functions tests. mRNA expression level of Toll-like receptor 4 (TLR4) in bone was determined by reverse transcription-polymerase chain reaction (RT-PCR) assay. The pathological changes of bone and tissue slides were prepared with hematoxylin and eosin (HE) staining for observing under microscope. RESULTS: Compared with normal group, leukocyte count of 4-hour LPS-treated group was significantly decreased (P 0.05). Blood urea nitrogen (BUN) was increased at 6 hours (P 0.05). Six hours after LPS treatment, the expression of TLR4 mRNA was enhanced (P<0.01) and reached the peak at 24 hours (P<0.01), and it remained at a high level at 72 hours (P<0.05). However, there were no significant pathological changes in bone structure after LPS treatment. CONCLUSION: Expression level of TLR4 mRNA in bone is significantly increased in endotoxemia mice.