The Role of Fibroblasts in Dystrophic Epidermolysis Bullosa Pathogenesis and Current Treatment Approaches

Abstract

Dystrophic epidermolysis bullosa (DEB) is a hereditary skin fragility disease characterized by the loss or dysfunction of collagen VII, predisposing patients to dermal–epidermal separation. This disease is highly associated with the development of progressive fibrosis of the skin and other organs and the occurrence of lethal cutaneous squamous cell carcinomas (cSCCs). These are not only caused by chronic wounding but also by collagen VII deficiency, which may directly alter cellular responses. This review focuses on the role of fibroblasts in DEB pathogenesis. In addition to keratinocytes, fibroblasts contribute to collagen VII production. Fibroblasts in injured DEB skin are activated and profibrotic and have a propensity to alter tissue homeostasis. Disease progression in DEB follows the trajectory of cancer injury through inflammation and fibrosis. Fibroblast activation and extracellular matrix remodeling that occur in advancing DEB may be directly linked to the aggressive biological behavior of DEB cSCCs. In contrast, the mechanisms underlying chronic itching and pain in DEB and the potential contribution of fibroblasts to these symptoms are only partially understood. The first therapies for DEB recently received regulatory approval, which is a major milestone toward a cure. However, to successfully treat DEB, systemic therapies to mitigate chronic inflammation and fibrosis are likely required, in addition to local collagen VII replacement.