COORDINATE EXPRESSION OF ALPHA5 BETA1 INTEGRIN AND FIBRONECTIN IN DUPUYTRENS DISEASE

The expression of alpha5 beta1 (alpha 5 beta 1) integrin and its extra cellular ligand fibronectin was studied immunohistochemically in 23 ca ses of Dupuytren's disease using an immunoperoxidase method for light microscopic visualization. All cases consisted of multiple nodules sho wing a variable degree of cellularity and fibrosis. Depending on the h istological appearance of these nodules, each case was assigned to the three following phases: proliferative, involutional and residual. Alp ha5 beta 1 integrin was detected in the highly cellular areas of both proliferative and involutional phases where fibronectin was simultaneo usly expressed in the extracellular matrix (ECM). Diversely alpha 5 be ta 1 and fibronectin disappeared from the hypocellular areas of involu tional phase, undergoing fibrotic transformation, and from the fibroti c connective tissue of residual phases. These findings indicate that t he expression pattern of alpha 5 beta 1 integrin correlates with the p resence in the ECM of the corresponding ligand fibronectin during the different phases of Dupuytren's disease. We suggest that alpha 5 beta 1 integrin, linking fibronectin to stromal cells of both proliferative and involutional phases, may be involved in the contractile processes occuring in Dupuytren's disease.