CELL BEHAVIOR AND CELL-MATRIX INTERACTIONS OF HUMAN PALMAR APONEUROTIC CELLS IN-VITRO

The present investigation has been performed to better characterize, i n vitro, normal aponeurotic cells in comparison with dermal fibroblast s and with cells derived from Dupuytren's affected aponeuroses. Cells were cultured in monolayer and/or into three-dimensional collagen gels . Cell structure, adhesion, and spreading capability on different subs trates, as well as integrin expression were investigated by light and electron microscopy and by flow cytometry. Cell-matrix interactions we re also analyzed by gel retraction experiments in the presence, or abs ence, of RGD peptides and anti-integrin antibodies. Normal aponeurotic cells, compared with dermal fibroblasts, exhibited in vitro peculiar structural features, which were substantially maintained in Dupuytren' s aponeurotic cells, irrespective of the substrate they were grown on. By contrast, the aponeurotic cell behavior was different in normal an d diseased cells, these latter approaching that of dermal fibroblasts. Normal aponeurotic cells, in fact, were characterized by low efficien cy in retracting the collagen gel, low alpha(2), alpha(1) and alpha(5) integrin subunit expression and low adhesion properties onto collagen and fibronectin, whereas cells isolated from the aponeuroses of Dupuy tren's patients exhibited higher capability of retracting the collagen gel, increased adhesion properties toward collagen and fibronectin, a nd higher levels of integrin expression. No differences were observed between dermal fibroblasts from Dupuytren's patients or from normal su bjects. These in vitro results are consistent with those previously ob tained in situ, suggesting that palmar aponeurotic cells have a peculi ar phenotype and that changes in cell-matrix interactions occur in Dup uytren's contracture. Moreover, by comparing data obtained from the re tracted fibrotic cords and the still clinically unaffected aponeuroses of the same patients, it may be noted that Dupuytren's disease is not only confined to the clinically involved branches, but includes the w hole aponeurosis of the affected hand. (C) 1997 Wiley-Liss, Inc.