Differential Angiogenesis between Skin and Gingival Fibroblasts During Wound Healing

Clinical observations and several evidences suggest that oral gingiva wounds heal faster and with less scarring than skin wounds. Objectives: We hypothesized that there are differences in angiogenesis pattern between skin and gingiva fibroblasts. Methods: Using a model of angiogenesis in vitro, we compared the angiogenic capacity of these cells and investigated the secretion of angiogenic growth factors by two types of fibroblasts during wound healing. Results: While both cell types promoted angiogenesis by means of soluble factors, injured gingiva fibroblasts showed an angiogenic capacity leading to the formation of capillary-like networks more important than their skin counterparts. Skin and gingival fibroblasts, either intact or after injury, were found to secrete a differential level of VEGF, FGF-2 and PDGF-AB. Intact gingival fibroblasts were found to secrete about 46 times more VEGF than their dermal counterparts.Interestingly, 5 hours after injury of gingival fibroblasts, VEGF level increased by 21% and returned to its initial value within the first day while no change was observed on its level in skin fibroblasts over 3 days. No change was observed in the secretion level of PDGF-AB after injury in both cell types. Major differences were observed with FGF-2 secretion level. Five hours after injury, gingival fibroblasts increased their secretion level by 115% while this increase in skin fibroblasts was of 291%. Conclusions: We demonstrate that there are site-specific differences in angiogenesis pattern between skin and gingival fibroblasts. Our work focuses on the role of mesenchyme in angiogenesis and its role in wound healing versus regeneration.