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Figure 3. Effects of soluble factors secreted by pulp fibroblasts on the tubular perimeters of capillary-like structures formed by endothelial cells. The quantitative evaluation was done by measurment of the tubular perimeters in 30 fields of view per group in 3 independent experiments. Results are expressed as mean ± SD. Endothelial cells were seeded on the 24-well culture plate on Matrigel and cultured in conditioned media obtained from intact or injured pulp fibroblasts. Control medium (not in contact with pulp fibroblasts) was also used. After endothelial cells were incubated with these media, the formation of the capillary network was observed by phase-contrast microscopy. (A) The perimeters of tubular structures formed by endothelial cells were measured and expressed as a percentage of the perimeters obtained after the incubation of endothelial cells with the control medium. A significant increase in tube perimeter was observed with the conditioned media from intact and injured pulp fibroblasts. There was a significant increase in the tubular perimeter with the conditioned medium obtained from injured as compared with that obtained from intact fibroblasts (*p < 0.05). (B) The addition of FGF-2 or VEGF neutralizing antibodies to the conditioned media obtained from injured pulp fibroblasts resulted in a reduction in the tubular perimeters as compared with those observed without neutralizing antibodies. This difference was statistically significant when both neutralizing antibodies were used. The tubular perimeters were measured and expressed as a percentage of those obtained from injured pulp cells without neutralizing antibodies (*p < 0.05).
