Dystrophic epidermolysis bullosa (DEB) is a severe skin fragility disorder associated with trauma-induced blistering, progressive soft tissue scarring, and increased risk of skin cancer. DEB is caused by mutations in type VII collagen. In this study, we describe the generation of a collagen VII hypomorphic mouse that serves as an immunocompetent animal model for DEB. These mice expressed collagen VII at about 10% of normal levels, and their phenotype closely resembled characteristics of severe human DEB, including mucocutaneous blistering, nail dystrophy, and mitten deformities of the extremities. The oral blistering experienced by these mice resulted in growth retardation, and repeated blistering led to excessive induction of tissue repair, causing TGF-β1-mediated contractile fibrosis generated by myofibroblasts and pseudosyndactyly in the extremities. Intradermal injection of WT fibroblasts resulted in neodeposition of collagen VII and functional restoration of the dermal-epidermal junction. Treated areas were also resistant to induced frictional stress. In contrast, untreated areas of the same mouse showed dermal-epidermal separation following induced stress. These data demonstrate that fibroblast-based treatment can be used to treat DEB in a mouse model and suggest that this approach may be effective in the development of clinical therapeutic regimens for patients with DEB. IntroductionSkin integrity and resistance to mechanical stress rely on the function of the dermal-epidermal junction zone (DEJZ), which anchors the epidermis to the underlying dermal matrix. The supramolecular cell adhesion complexes at the DEJZ mediate interactions of the cytoskeleton in basal keratinocytes with the basement membrane and the extracellular anchoring fibrils, which emanate from the basement membrane into the dermis and entrap dermal collagen bundles, thus establishing stable dermal-epidermal cohesion (1).The main component of the anchoring fibrils is collagen VII, a homotrimeric collagen synthesized by keratinocytes and fibroblasts (2). Fibril formation and deposition at the DEJZ requires proteolytic processing of procollagen VII to mature collagen (3). Loss of collagen VII functions in dystrophic epidermolysis bullosa (DEB) leads to absence or anomalies of the anchoring fibrils and to dermal-epidermal tissue separation. DEB refers to a clinically heterogeneous group of disorders including recessively and dominantly inherited subtypes (4, 5). All forms of DEB are allelic and caused by mutations in the collagen VII gene, COL7A1. Early investigations demonstrated reduced amounts of anchoring fibrils and collagen VII in the skin of patients with mild and moderate, reces-
Collagen XVII/BP180, an epidermal adhesion molecule, exists as a full-length transmembrane protein and as a soluble 120-kd ectodomain that is shed from the keratinocyte surface by furin-mediated proteolysis. Despite a number of studies on autoantibody targets in blistering skin diseases, it has remained unclear whether the physiologically shed ectodomain of collagen XVII plays a role as an autoantigen. Here we isolated the authentic, soluble form of human collagen XVII and showed that it is an autoantigen recognized by IgG and IgA autoantibodies in different blistering skin diseases and is, in some cases, the preferential target. The ectodomain was isolated from the epidermis, keratinocyte media, amniotic fluid, and pemphigoid blister fluid, and autoantibodies affinity-purified with this ectodomain bound to the proximal surface of the epidermis in normal skin but not in collagen XVII-deficient skin. The antibody reactivity was not dependent on the native conformation or the N-glycosylation of the soluble ectodomain, but was abolished by collagenase treatment. Sera of 81 patients with a clinically active blistering skin disease were reacted with full-length collagen XVII, the authentic soluble ectodomain, and recombinant fragments. In bullous and cicatricial pemphigoid, IgG reactive with full-length collagen XVII also recognized the soluble ectodomain. In linear IgA dermatosis and chronic bullous dermatosis of childhood, IgA targeted the soluble ectodomain more efficiently than the full-length protein. The use of recombinant fragments demonstrated that epitopes were present in several noncollagenous and collagenous subdomains of the molecule, and that a significant portion of the sera targeted Col15 domain, a hitherto unrecognized epitope region.
Compression bandaging is a major cornerstone in the treatment of chronic venous insufficiency. Its efficacy considerably depends on the applied pressure and it is therefore largely dependent on the individual applying the system. The sub-bandage pressure was measured under three consecutive compression bandages applied by 21 nurses before and after training and the introduction of a pressure monitor (Kikuhime, MediTrade, Denmark). A questionnaire was used to evaluate the self-rating before and after the intervention. Before intervention, a questionnaire showed the confidence of the nurses in reaching sufficient sub-bandage pressure levels. However, 34.9% of all bandages were shown to be insufficient before intervention (< 20 or > or = 60 mmHg) and only 17.5% after intervention, representing a statistically significant improvement through intervention. Of the insufficient bandages, 77.3% were applied by nurses with more than 10 years of working experience. Furthermore, the mean sub-bandage pressure in active standing position, a marker for the working pressure, was improved form 38.7 to 64.3 mmHg after intervention. Continuous awareness and training are necessary to maintain sufficient compression bandaging. The availability of a pressure monitor was helpful to reach this goal. Long work experience and self-rating alone is not sufficient to maintain adequate quality in compression bandaging.
Background Junctional epidermolysis bullosa (JEB), a group of hereditary skin fragility
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