This work area extends the investigations from simple polarized epithelia to the multilayered epidermis. The epidermis consists of a basement membrane-anchored regenerative compartment and multiple non-polarized suprabasal cell layers with distinct differentiation features. In analogy to project area A, the goal of this work area is to map forces within epidermal organoids/equivalents. We further investigate (i) how the force balance is affected upon disruptive intervention and in genetic diseases of the cytoskeleton and (ii) how forces are sensed by nociceptive neurons.
B1 compares the confluent keratinocyte monolayers and epidermal equivalents to measure forces at the cellular and subcellular level and their perturbations upon stretching and wounding.
B2 uses 2D and 3D keratinocyte culture systems to study differences in mechanoresponses of keratinocytes obtained from patients with either blistering or hyperproliferative skin diseases.
B3 will combine the epidermal equivalents with novel biomaterials and nerve cells to build a co-culture system from primary keratinocytes and iPSC-derived mechanosensitive neurons obtained from healthy individuals or patients with genetic mutations leading to defective mechanosensation.
Together, the projects aim to contribute to our understanding of the effects of mechanical stress, wounding and genetic diseases on epidermal mechanoresponses and mechanosensation.
Impact: The expected results will identify hitherto unknown mechanisms of epidermal responses to disruption of the force equilibrium with very high spatial and temporal resolution (B1, B2). These insights will help to positively influence mechanoresponses and tissue reorganization upon extensive stress, wounding and in genetic skin diseases. The established systems will also facilitate future "omics" approaches for pathway identification. The co-culture system in B3 extends the approach to include a consideration of the multicellular nature of the epidermis focusing on neuronal mechanosensation, which is the most debilitating aspect of epidermal wounding and keratinopathies.