Differential expression of collagen integrin receptor on fetal vs. adult skin fibroblasts: implication in wound contraction during healing.

BACKGROUND: Fetal skin wound healing is characterized by an absence of contraction and scar formation, two important observations associated with adult healing often leading to pathological problems.
OBJECTIVES: We have studied the capacity of adult and fetal human skin fibroblasts to contract collagen gels, collagen being the major structural component of dermal matrix.
METHODS: In parallel with collagen gel contraction studies, we have used fluorescence-activated cell sorter analysis to study the levels of collagen receptors expressed at the surface of fibroblasts derived from fetal or adult skin samples.
RESULTS: Strong differences were detected between freshly isolated fetal and adult fibroblasts. Fetal fibroblasts had a very low capacity to contract collagen gel, whereas adult cells significantly contracted gels in the same conditions. The expression of alpha1, alpha2 and alpha3 integrin subunits was also significantly different depending of the donor age: alpha1 and alpha3 integrin subunit expression was lower in fetal cells compared with adult cells, whereas alpha2 integrin subunit expression was higher. When grown in monolayers, adult cells showed rapid changes in their contractile capacity and integrin expression while fetal cells were only affected after several passages.
CONCLUSIONS: These observations indicate that intrinsic differences between fetal and adult fibroblasts can strongly influence the quality of wound repair.