Attachment of intrinsically and extrinsically aged fibroblasts on collagen and fibronectin.
In the present study we compare human dermal fibroblasts from donors of different age and from sites differing in sun exposure for their capacity to adhere to collagen or fibronectin. Attachment of cells was not dependent on the collagen concentration but was clearly dependent on the fibronectin concentration used for the coating of the plastic surfaces. Attachment of fibroblasts to collagen and fibronectin is dominated by specific integrin binding: only few cells were able to attach to collagen after inhibition with an anti-VLA 2 antibody, or to attach to fibronectin after inhibition with an anti-VLA 5 antibody. On unexposed sites, cells from old donors showed a significantly increased adhesion capacity on collagen (plus 50.7%) and on fibronectin (plus 62.4%) and an increased staining pattern of VLA 2 and VLA 5 integrins in immunohistochemistry in comparison with young donors. In contrast fibroblasts of chronically sun-exposed skin had a significantly decreased adhesion capacity both on collagen (minus 55.3%) and on fibronectin (minus 46.5%) and a poor staining pattern of the above integrins in comparison with cells from solely aged skin (unexposed sites of old donors). Adhesion of all cells could be inhibited by specific integrin antibodies showing that the employed antibodies were able to detect the epitopes responsible for attachment. Intrinsic and extrinsic aging are able to alter cellular properties of mesenchymal cells, such as adhesion to physiologically relevant macromolecules of the extracellular matrix.