Bacterial LPS enhances VEGF expression in dental pulp cells and macrophages

*1083 Bacterial LPS enhances VEGF expression in dental pulp cells and macrophages*
T.M. BOTERO, M.G. MANTELLINI, W. SONG, C.T. HANKS, and J.E. NÖR, University of Michigan, Ann Arbor, USA Aberrant pulp neovascularization is observed in caries-induced pulpitis and might be involved in increased intrapulpal pressure and pain. Vascular Endothelial Growth Factor (VEGF) is one of the major regulators of neovascular responses throughout the body, but little is known about its function in the dental pulp. Objectives: The purpose of this in vitro study was to examine the effect of a bacterial lipopolysacharide (LPS) on the expression of VEGF in dental pulp cells and macrophages (Mų). Methods: Mouse Mų (Raw), odontoblast-like cells (MDPC-23) and undifferentiated dental pulp cells (OD-21) were cultured in 12-well plates, and grown in DMEM/10% FBS at 37°C. After 24 h, the culture medium was changed and 0, 1, 10 or 20 µg/ml LPS from escherichia coli (055:B5) were added. VEGF expression in the conditioned medium (CM) was determined in triplicate wells by ELISA (mouse VEGF Quantikine Elisa Kit, R&D Systems). The percentage of viable cells in each group was determined by Trypan Blue exclusion. The statistical significance of the data was determined at (p<0.05) with one-way ANOVA or t-test. Results: CM from Mų exposed to 20 µg/ml LPS expressed a 10-fold increase in VEGF expression compared to untreated Mų (54±27.5 and 4.7±2.9 pg/ml respectively). The baseline VEGF expression level was high in CM from MDPC-23 cells (300±17.5 pg/ml), and exposure to LPS upregulated VEGF expression in these cells (475±88.9 pg/ml) (p=0.04). In contrast, dental pulp cells (OD-21) showed a high baseline level of VEGF expression (495±57.13 pg/ml), but did not show upregulation of VEGF expression upon exposure to LPS (p>0.05). The survival of Mų, MDPC-23, or OD-21 cells was not affected by exposure to LPS. Conclusions: These results demonstrate that LPS upregulates VEGF expression in macrophages and in MDPC-23 odontoblast-like cells, but not in OD-21 undifferentiated dental pulp cells. Supported by Dept. of Cariology, Rest. Sciences, Endodontics.
Seq #112 - Growth Factors; Regulation of Cell Function; Forensic Dentistry 3:45 PM-5:00 PM, Thursday, 7 March 2002 San Diego Convention Center Exhibit Hall C
Back to the Pulp Biology Program Back to the IADR/AADR/CADR 80th General Session (March 6-9, 2002)
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