ABSTRACT
BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a rare skin blistering disease with a prevalence of 0.2/ million people. EBA is characterized by autoantibodies against type VII collagen. Type VII collagen builds anchoring fibrils that are essential for the dermal-epidermal junction. The pathogenic relevance of antibodies against type VII collagen subdomains has been demonstrated both in vitro and in vivo. Despite the multitude of clinical and immunological data, no information on metabolic changes exists. METHODS: We used an animal model of EBA to obtain insights into metabolomic changes during EBA. Sera from mice with immunization-induced EBA and control mice were obtained and metabolites were isolated by filtration. Proton nuclear magnetic resonance (NMR) spectra were recorded and analyzed by principal component analysis (PCA), partial least squares discrimination analysis (PLS-DA) and random forest. RESULTS: The metabolic pattern of immunized mice and control mice could be clearly distinguished with PCA and PLS-DA. Metabolites that contribute to the discrimination could be identified via random forest. The observed changes in the metabolic pattern of EBA sera, i.e. increased levels of amino acid, point toward an increased energy demand in EBA. CONCLUSIONS: Knowledge about metabolic changes due to EBA could help in future to assess the disease status during treatment. Confirming the metabolic changes in patients needs probably large cohorts.
Subject(s)
Autoantibodies/blood , Collagen Type VII/immunology , Epidermolysis Bullosa Acquisita/metabolism , Epidermolysis Bullosa Acquisita/physiopathology , Metabolomics/methods , Animals , Autoantibodies/immunology , Blood Glucose/analysis , Collagen Type VII/administration & dosage , Dermis/immunology , Dermis/metabolism , Dermis/pathology , Epidermis/immunology , Epidermis/metabolism , Epidermolysis Bullosa Acquisita/etiology , Epidermolysis Bullosa Acquisita/immunology , Humans , Isoleucine/blood , Lactose/blood , Magnetic Resonance Spectroscopy/methods , Mice , Proline/blood , Skin/immunology , Skin/metabolism , Skin/pathologyABSTRACT
Type VII collagen as component of anchoring fibrils plays an important role in skin architecture, however, no detailed structural information is available. Here, we describe the recombinant expression, isotope labeling, and (1)H, (15)N, (13)C chemical shift assignment of a subdomain of the murine type VII collagen - the von-Willebrand-factor-A-like domain 2 (mvWFA2). vWFA2 interacts with type I collagen and plays a central role in certain skin blistering diseases. Based on these assignments a secondary structure prediction was performed showing a properly folded protein. An interaction of mvWFA2 with its neighboring domain mFNIII-9 was characterized with NMR spectroscopy and SPR.
