CORRELATION OF ALPHA-SMOOTH MUSCLE ACTIN EXPRESSION AND CONTRACTION IN DUPUYTRENS DISEASE FIBROBLASTS

We studied 11 nodules from patients with Dupuytren's contracture to de termine whether alpha-smooth muscle actin expression in Dupuytren's fi broblasts is related to the generation of contractile force. Tissue wa s placed into explant culture and fibroblast strains were obtained. Th e mean percent of cultured Dupuytren's fibroblasts expressing alpha-sm ooth muscle actin, as determined by immunofluorescence, was 14 +/- 8 a nd ranged from 1% to 26%. The ability of Dupuytren's fibroblasts to ge nerate contractile force was determined by using a previously describe d collagen lattice contraction assay. We observed a significant positi ve correlation between the expression of alpha-smooth muscle actin and the generation of contractile force in cell strains of Dupuytren's fi broblasts. In addition, six fibroblast strains from palmar fascia of i ndividuals undergoing carpal tunnel release were examined. In six stra ins of palmar fibroblasts the mean percent of cells expressing alpha-s mooth muscle actin was 5 +/- 3 and ranged from 1% to 9%. Six Dupuytren 's fibroblast strains, in which more than 15% of the cells expressed a lpha-smooth muscle actin, were significantly more contractile than the palmar fibroblasts. These results suggest that Dupuytren's fibroblast s can acquire smooth muscle characteristics and that the acquisition o f a smooth muscle-like phenotype correlates with increased contractili ty.