Engineered natural extracellular matrix platform for modelling skin diseases and therapeutic targets discovery

INTRODUCTION: Dysregulation of the dermal extracellular matrix (ECM) drives skin pathologies by influencing tissue mechanics, dermal-epidermal adhesion, and disease progression. However, current in vitro models often fail to replicate native ECM complexity or disease-specific alterations, limiting mechanistic studies and therapeutic target discovery. This gap is particularly critical for untreatable skin fragility disorders, where abnormal dermal ECM underlies severe clinical manifestations. OBJECTIVES: This study aimed to develop and validate an engineered natural ECM (NatECM) platform that recapitulates key compositional and biomechanical features of fibroblast-derived dermal ECM. As a proof-of-concept, we applied NatECM to model clinically distinct variants of dystrophic epidermolysis bullosa (DEB), the skin fragility disorders prototype, to identify ECM-related and disease-specific alterations and to interrogate candidate therapeutic targets. METHODS: Primary fibroblasts from healthy donors and DEB patients were cultured to self-assemble their ECM, generating NatECM dermal equivalents. ECM organization was evaluated by immunostaining and ultrastructural analyses, nano- and macro-scale mechanical properties were measured by atomic force microscopy and uniaxial tensile testing, and ECM composition was characterized by proteomics. Functional relevance was evaluated by keratinocyte adhesion assays and fibulin-5 supplementation experiments. RESULTS: NatECM reproduced intrinsic fibroblast-derived dermal ECM features and captured disease-associated mechanical and structural impairments characteristic of DEB. Across DEB variants, NatECM unveiled subtype-specific proteomic alterations that affect ECM structure and elastic fiber formation. We identified a "fragility quartet" - fibulin-5, decorin, and collagens III and V - consistently downregulated across all variants and linked to defective ECM mechanics. Fibulin-5 supplementation restored ECM elastic behavior and strengthened keratinocytes adhesion, supporting its role as a candidate ECM regulator. CONCLUSION: The NatECM platform faithfully models fibroblast-derived dermal ECM and enables the identification and functional investigation of key molecular ECM regulators in DEB. Its tunability and physiological relevance position NatECM as a robust tool for studying ECM-driven skin disorders and for accelerating the identification of candidate therapeutic targets.