IADR Abstract Archives
Autocrine Pulp Fibroblast Function Modulation via Complement C3a Local Production
Objectives: Local Complement activation in dental tissues plays a major role, not only in eliminating bacteria but also in the initial steps of dental tissue regeneration. C3a is the first active molecule secreted by pulp fibroblasts after Complement activation. Recent data demonstrated that this active molecule mobilizes pulp stem cells (DPSCs) and provides a gradient for pulp fibroblast recruitment. This work was designed to investigate C3a autocrine modulatory effect on pulp fibroblasts growth factors secretion and, subsequently, on fibroblast proliferation and DPSCs recruitment.
Methods: Human pulp cells were isolated from third molars. DPSCs were separated from fibroblasts using magnetic cell sorting with STRO-1. Pulp fibroblasts were either stimulated with C3a (200ng/ml) or incubated with 1µg/ml Lipoteichoic Acid (LTA) to simulate a carious lesion. After 48h, the secretion of FGF2, TGFb1 and VEGF by pulp fibroblasts (± C3a specific antagonist) was quantified by ELISA. After this stimulation, the resulting supernatants were harvested and used to investigate their effects on unstimulated pulp fibroblasts proliferation with the MTT test. DPSCs recruitment towards the stimulated fibroblasts was investigated in Boyden chambers.
Results: Both cell incubation with LTA or stimulation with C3a significantly increased FGF2, TGFb1 and VEGF secretion. The supernatants obtained after both stimulation methods significantly induced fibroblast proliferation as compared to unstimulated cell supernatants or after cell incubation of with the C3a antagonist. An important level of DPSCs recruitment was observed with LTA-stimulated and C3a-stimulated fibroblast supernatants as compared with the unstimulated and with supernatants of fibroblasts incubated with the C3a antagonist.
Conclusions: Within the limits of this investigation, C3a complement fragment stimulate growth factor secretion by pulp fibroblasts and modulate fibroblast proliferation and DPSC recruitment. This autocrine stimulation of pulp fibroblasts is a new step in understanding the link between pulp tissue injury/inflammation and regeneration.
Methods: Human pulp cells were isolated from third molars. DPSCs were separated from fibroblasts using magnetic cell sorting with STRO-1. Pulp fibroblasts were either stimulated with C3a (200ng/ml) or incubated with 1µg/ml Lipoteichoic Acid (LTA) to simulate a carious lesion. After 48h, the secretion of FGF2, TGFb1 and VEGF by pulp fibroblasts (± C3a specific antagonist) was quantified by ELISA. After this stimulation, the resulting supernatants were harvested and used to investigate their effects on unstimulated pulp fibroblasts proliferation with the MTT test. DPSCs recruitment towards the stimulated fibroblasts was investigated in Boyden chambers.
Results: Both cell incubation with LTA or stimulation with C3a significantly increased FGF2, TGFb1 and VEGF secretion. The supernatants obtained after both stimulation methods significantly induced fibroblast proliferation as compared to unstimulated cell supernatants or after cell incubation of with the C3a antagonist. An important level of DPSCs recruitment was observed with LTA-stimulated and C3a-stimulated fibroblast supernatants as compared with the unstimulated and with supernatants of fibroblasts incubated with the C3a antagonist.
Conclusions: Within the limits of this investigation, C3a complement fragment stimulate growth factor secretion by pulp fibroblasts and modulate fibroblast proliferation and DPSC recruitment. This autocrine stimulation of pulp fibroblasts is a new step in understanding the link between pulp tissue injury/inflammation and regeneration.