Pseudosyndactyly - an inflammatory and fibrotic wound healing disorder in recessive dystrophic epidermolysis bullosa.

Abstract

A genetic blistering skin disease, recessive dystrophic epidermolysis bullosa (RDEB), is marked by severe wound healing defects and finger contractures. The purpose of this investigation was to elucidate the mechanisms of impaired wound healing and pseudosyndactyly occurring in RDEB patients by studying the role of known inflammation and fibrosis markers in RDEB pseudosyndactyly tissue. We studied the expression of the fibrosis and/or inflammation markers tenascin-C, α-smooth muscle actin, transforming growth factor-β1, interleukin-1β, and interleukin-6 in scarring and nonscarring tissue from healthy donors and RDEB patients by semiquantitative real time-PCR and, where applicable, by immunoblots. Furthermore, the distribution pattern of α-smooth muscle actin and tenascin-C were assessed by immunofluorescence microscopy. Based on mRNA and protein analysis, we found upregulation of tenascin-C, interleukin-1β, and interleukin-6 - but not of transforming growth factor-β1 - in recessive dystrophic epidermolysis bullosa scar samples taken from pseudosyndactyly hands. Unexpectedly, α-smooth muscle actin was not upregulated. Our results confirm inflammation and fibrosis in recessive dystrophic epidermolysis bullosa, especially in scars, suggesting major roles for these processes in pseudosyndactyly. Our data therefore suggests the potential use of antiinflammatory and antifibrotic drugs in the prevention of pseudosyndactyly.