ABSTRACT
Objective:To investigate the effects of Porhyromonas endodontalis(P.e)liopolysaccharide(LPS)on the expression of IL-23mRNA and protein in mouse osteoblasts MC3T3-E1 and the role of phosphatidylinositol 3-Kinases (PI3K)signaling pathway in this process.Methods:MC3T3-E1 cells were treated with different concentrations of P.e LPS for different hours,or pretreated with LY294002,a special PI3K inhibitor.The IL-23 mRNA and protein expression levels were detected by real-time PCR and Western blot respectively.Results:The level of IL-23 mRNA increased in MC3T3-E1 cells with the increase of concentration and the treatment time of P.e LPS(P <0.05).The IL-23 protein expression was increased by P.e LPS in a time dependent manner(P <0.05).The mRNA and protein of IL-23 decreased(P <0.05)after pretreatment with LY294002.Conclusion:P.e LPS can induce the expression of IL-23 mRNA and protein in MC3T3-E1 cells,and the PI3K signaling pathway may play a part in this process.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis (Pe) on the expression of macrophage colony stimulating factor (M-CSF) mRNA and protein in MC3T3-E1 cells and the role of nucler factor-κB (NF-κB) in the process.</p><p><b>METHODS</b>MC3T3-E1 cells were treated with different concentrations of Pe-LPS (0-50 mg/L) and 10 mg/L Pe-LPS for different hours (0-24 h). The expression of M-CSF mRNA and protein was detected by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunoadsordent assay (ELISA). The cells untreated by Pe-LPS served as control. The expression of M- CSF mRNA and protein was also detected in 10 mg/L Pe- LPS treated MC3T3-E1 cells after pretreated with BAY 11-7082 for 1 h, a special NF-κB inhibitor. The groups were divided as follows, control group, BAY group (10 µmol/L BAY 11-7082 treated alone MC3T3-E1 cells), Pe-LPS group (10 mg/L Pe-LPS stimulated MC3T3-E1 cells for 6 h), BAY combine with Pe-LPS group (10 µmol/L BAY 11-7082 pretreated cells for 1 h and 10 mg/L of Pe-LPS stimulated MC3T3-E1 cells for 6 h).</p><p><b>RESULTS</b>The level of M- CSF mRNA and protein increased significantly after treatment with different concentrations of Pe-LPS (0-50 mg/L), which indicated that Pe-LPS induced osteoblasts to express M-CSF mRNA and protein in dose dependent manners. The expression of M-CSF protein increased from (35 ± 2) ng/L (control group) to (170 ± 8) ng/L (50 mg/L group). Maximal induction of M-CSF mRNA expression was found in the MC3T3- E1 cells treated with 10 mg/L Pe-LPS for 6 h. After 6 h, the expression of M-CSF mRNA decreased gradually. The expression of M-CSF protein also increased with the treatment of 10 mg/L Pe-LPS for 10 h [(122 ± 4) ng/L]. After 10 h, the expression of M-CSF protein decreased gradually. The mRNA and proteins of M-CSF decreased significantly after pretreatment with 10 µmol/L BAY 11-7082 for 1 h. There was no significant difference between BAY group and the control.</p><p><b>CONCLUSIONS</b>Pe-LPS may induce the expression of M-CSF mRNA and protein in MC3T3-E1 cells through the signaling of NF-κB.</p>