Institute of Biological Information Processing (IBI-2): Mechanobiology, Forschungszentrum Jülich (FZJ)
3D-mapping of epidermal tissue mechanobiology during growth and upon wounding
Project overview. Simplified epidermal equivalents are prepared from primary and immortalized healthy keratinocytes or mutated keratinocyte cell lines. They are preconditioned by cyclic mechanical stretching in a self-made device. Subsequently, mechanical, and molecular properties are quantified under external strain and during healing of model wounds. Parallel experiments on skin ensure physiological relevance.
Institute of Molecular and Cellular Anatomy (MOCA), Uniklinik RWTH Aachen
Consequences of keratin mutations on epidermal tissue mechanics and mechanoresponses
Project overview. (A) shows the high throughput compression devise designed and constructed by the team of Horst Fisher (project area D). (B) highlights the altered response in Pachyonychia congenita (PC)-derived epidermal equivalents. The fluorescence micrographs show sections of wild-type (WT)- and PC-derived (K6aN171del) skin models that were subjected to cyclic compression (47 mbar, 150 mHz, 1h/day, 5 days) or not. The epidermal equivalents were immunostained 4 days after mechanical stress with antibodies against laminin 332 (magenta) to delineate the basement membrane and against keratin 10 (green) to indicate vital suprabasal epidermal layers. Nuclei are stained with Hoechst 33258 (blue). The outermost border of the stratum corneum is demarcated by a dashed line. Scale bars, 50 µm. The histogram at right quantifies the mechanical stress-induced enlargement of the epidermal compartment (including the stratum corneum) in the PC-derived model (mean ± SD). (C) summarizes aspects that are addressed experimentally in the project.
Institute of Neurophysiology, Uniklinik RWTH Aachen
Mechanical triggers in painful skin diseases
Project overview. (A) Diseases selected for studies on mechanically-induced pain. (B) Neurites from mouse dorsal root ganglions (DRGs) are are guided in the vertical direction by microgels in an Anisogel (left). Presence of peripheral neuronal stem cells (green) improves overall DRG neurite growth (cyan; right). (C) depicts the different components used for keratinocyte-neuron co-cultures: (Left) Fibronectin coating (red) covalently linked to the top of a 3D PEG-based hydrogel. (Middle) Keratinocytes forming a continuous monolayer (green) on top of the fibronectin coated PEG gel. (Right) Co-culture of a mouse DRG (red) with keratinocyte (green)/fibronectin layers on top. Note the neurites approaching the epithelial monolayer. (D) Schemes of methods used to apply mechanical stimulation. (E) shows patch-clamped neurons cultured on top of a patterned light-responsive hydrogel at left. A change in membrane potential is detected when neurites are mechanically stimulated by light-actuated hydrogel deformation pulse (middle). Co-culture of neurons with keratinocytes on top of these hydrogels shows the formation of contact points between neurites and keratinocytes (right).
Institute of Molecular Pharmacology, Division of Pharmacology in Inflammation, Uniklinik RWTH Aachen
Role of ion channels and ADAM-family metalloproteinases in mechanobiology
Project overview. (A) The scheme depicts a model for activation of ADAM10/17-mediated shedding events by mechanical activation of Piezo-1 and TRPV4 in HaCaT cells. The photograph below shows the stretch chamber (from the Merkel team) used for mechanical stimulation at left and a scheme of the co-culture system at right. (B) Piezo-1 is activated by Yoda 1 or mechanical stretch and, in turn, enhances ADAM activity. Conversely, ADAM activity is suppressed by knockdown of Piezo-1 (grey bars). (C) Activation of TRPV4 by GSK1016790A or mechanical stretch induces ADAM activity, which is suppressed by the TRPV4 inhibitor HC067047 (grey bar). The project aims to translate these findings into (patho) physiological settings and functions using primary keratinocytes and organotypic skin models.
