Effect of lipopolysaccharides on vascular endothelial growth factor expression in mouse pulp cells and macrophages

Abstract

Vascular endothelial growth factor (VEGF), a potent pro-angiogenic factor, might regulate the neovascularization observed in the pulp of teeth with deep caries. The purpose of this in vitro study was to evaluate the effect of bacterial lipopolysaccharides (LPS) on VEGF expression in dental pulp cells. Mouse odontoblast-like cells (MDPC-23) or undifferentiated pulp cells (OD-21) were exposed to 0-20 microg ml-1Escherichia coli LPS or 0-80 microg ml-1Prevotella intermedia LPS. As controls, mouse macrophages or gingival fibroblasts were exposed to LPS, since these cells are known to secrete VEGF. The VEGF expression was evaluated by reverse transcriptase polymerase chain reaction or enzyme-linked immunosorbent assay. The baseline expression levels of VEGF protein were higher in MDPC-23 and OD-21 than in fibroblasts or macrophages. Vascular endothelial growth factor protein expression was upregulated in MDPC-23 and macrophages exposed to E. coli LPS, but not in OD-21 cells or fibroblasts. Higher concentrations of P. intermedia LPS were required to induce VEGF expression in MDPC-23 cells. Treatment with LPS did not affect VEGF expression at the mRNA level in any of the cells evaluated. These results demonstrate that bacterial LPS upregulates VEGF expression in odontoblast-like cells and macrophages, and suggest that the regulation of VEGF expression occurs primarily at a post-transcriptional level.

Potential role of odontoblasts in the innate immune response of the dental pulp

“…32 The expression of the proangiogenic chemokine, CXCL2, is strongly up-regulated in LTA-stimulated odontoblasts, suggesting that CXCL2 might thus contribute to the increased vascularization by binding to CXCR2 that is highly expressed on endothelial cells. 30 An in vitro study by Bofero et al 33 has revealed that odontoblast-like cells stimulated by LPS up-regulate vascular endothelial growth factor (VEGF) expression suggesting a novel role for odontoblasts in the regulation of pulpal angiogenesis. Up-regulated VEGF synthesis by odontoblasts stimulated with LPS might increase the permeability of existing pulp blood vessels, thus facilitating the process of diapedesis of neutrophils, lymphocytes, and monocytes.…”

MicroRNA 665 Regulates Dentinogenesis through MicroRNA-Mediated Silencing and Epigenetic Mechanisms

“…HEK-293T, rat dental pulp MDPC-23, and rat odontoblast OD-21 cells (57) were cultured at 37°C, and mouse odontoblast-like M06-G3 cells (58) were maintained at 33°C, all in 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) supplemented with 4.5 g/liter glucose, L-glutamine, sodium pyruvate (Cellgro, VA), 10% fetal bovine serum (Atlanta Biologicals, GA), 100 g/ml streptomycin, 100 units/ml penicillin (Gibco, NY), and 250 g/ml amphotericin B (Cellgro, VA). To induce differentiation, medium was further supplemented with 50 g/ml ascorbic acid, 10 mM ␤-glycerophosphate, and 1 ϫ 10 Ϫ7 M dexamethasone (Sigma-Aldrich, St. Louis, MO) for up to 21 days.…”

Expression of Angiogenic Factors in Rat Periapical Lesions

“…Vascular endothelial growth factor (VEGF) is considered a key regulator of vascular permeability and one of the major inducers of angiogenesis (12)(13)(14). VEGF-initiated signals may play a critical role in the development of pulp inflammation because cariogenic bacteria induce VEGF up-regulation in dental pulp cells that express VEGFR2 (15,16).…”