Deciphering the role of laminin β4 in basement membrane function

• Applicant: Dr. Manuela Pigors
• Subject Area: Dermatology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567306702

Laminin β4 has recently been identified as a key structural component of the dermal-epidermal junction and an autoantigen in anti-p200 pemphigoid, a rare autoimmune disease characterized by skin blistering and, less frequently, mucosal lesions, primarily in the oral cavity. Our previous research has shown that epidermal keratinocytes are the main source of laminin β4, which likely forms complexes with laminin α3 and either the γ1 and/or γ2 chains. However, the precise biological function of laminin β4 remains poorly understood. This project aims to investigate the structural and functional role of laminin β4 in the skin and oral mucosa, particularly within the basement membrane zone. We will employ high-throughput protein-protein interaction mapping in human keratinocytes and skin extracts to identify additional binding partners of laminin β4. Furthermore, functional studies using knockdown and overexpression experiments in two-dimensional keratinocyte cultures will assess the effects of altered laminin β4 expression on keratinocyte function, interactions with other laminin chains, and newly identified binding proteins. These experiments will also provide insights into the localization and distribution of laminin β4 within cells and the extracellular matrix. To further elucidate laminin β4-associated molecular networks, we will apply omics-based approaches, including transcriptome, proteome, and kinome profiling, as well as multiplex immunoassays. Additionally, three-dimensional organotypic co-culture models of skin and oral mucosa will be developed to study laminin β4’s role in tissue organization, basement membrane integrity, and extracellular matrix dynamics. Using laminin β4-deficient keratinocytes and single/double knockdowns of validated binding partners, we will analyze molecular pathways through transcriptomic and proteomic profiling, histological and immunofluorescence staining, electron microscopy, and wound healing assays. These experiments will distinguish functional and physical interactions of laminin β4, identify compensatory pathways, and provide deeper insights into its role in skin and mucosal cell-matrix interfaces.

• DFG Programme: Research Grants