| 2883 Dental Pulp Cells Express Lipopolysaccharides Receptors | ||
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T.M. BOTERO1, C.E. SHELBURNE2, T. JIN2, C.T. HANKS2, and J.E. NOR2, 1University of Michigan, Assistent Professor, Ann Arbor, USA, 2University of Michigan, Ann Arbor, USA Dental pulp cells express lipopolysaccharides receptors BOTERO T. M.*, SHELBURNE C. E., JIN T., HANKS C. T., NÖR J.E. University of Michigan, School of Dentistry, Ann Arbor, Michigan, USA. CD14 and TLR4 are lipopolysacharides's membrane receptors, which activate intracellular signaling pathways for protein expression. We previously found that LPS induced up-regulation of vascular endothelial growth factor by odontoblast-like cells, but the mechanisms are unknown. “Objectives:” To evaluate the expression of CD14 and TLR4 in mouse odontoblasts-like (MDPC-23) and undifferentiated dental pulp cells (OD-21). “Methods:” Cells were cultured in DMEM/10% FBS at 37°C. RNA from cells exposed for 30 min to 0-20 ?g/ml E. coli LPS, was extracted for RT-PCR and Real time PCR. Alternatively cells were exposed to anti-mouse CD14, TLR4, or IgG antibody as controls and analyzed by flowcytometry and immunohistochemistry. Macrophages (Raw 264.7 ATCC) and gingival fibroblasts were used as controls. Three independent experiments were done in triplicate and data were analyzed by one-way ANOVA or Student's t-test (p<0.05). “Results:” RT-PCR analysis reveled that MDPC-23, OD-21, macrophages and fibroblasts expressed CD14 and TLR4. However OD-21 expressed very low levels of TLR4. Real time PCR, confirmed RT-PCR data. When the cells were exposed to 0.2 ?g/ml E. coli LPS, CD14 expression was increased in all cells except for OD-21. At 20 ?g/ml E. coli LPS, TLR4 expression was increased in comparison with untreated cells in MDPC-23 and macrophages. By immunohistochemistry and flowcytometry, CD14 and TLR4 were highly expressed in MDPC-23 and macrophages, but not in OD-21 or fibroblasts. “Conclusion:” Odontoblast-like cells express both CD14 and TLR4, two important mediators of lipopolysaccharides signaling. In contrast, undifferentiated dental pulp cells express TLR4 but low levels of CD14. Supported by CRSE grant, School of Dentistry, University of Michigan and American Association of Endodontics grant. | ||
| Seq #320 - Pulp Biology and Physiology II 2:00 PM-4:00 PM, Saturday, 12 March 2005 Baltimore Convention Center Exhibit Hall E-F | ||
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