Mechanobiological cross-talk between epithelia and their immediate environment

Project Area C
Is to study the interaction of epithelia with their surroundings. Epithelia as boundary-forming tissues are interacting with other tissue types. For example, epithelial-endothelial, and epithelial-inflammatory cell cross-talk is at the core of many pulmonary diseases, and epithelial-connective tissue cross-talk determines epithelial pathophysiological differentiation and aging. The involvement of mechanical signals in these processes is poorly understood, despite its high clinical relevance. The goal of project area C is to investigate modes of different types of cross-talk at the single cell and tissue level and to identify the underlying molecular pathways to facilitate tissue engineering and disease management. The selected paradigms address these questions in the respiratory system that is involved in breathing (inspiration and expiration) and gas exchange. Here, mechanical forces act on the topological outside, i.e., ventilation, as well as on the inside via capillaries, i.e., blood flow (C1, C2, C3), all of which are coupled to connective tissue. The new project C4 adds another degree of complexity by dealing with the retinal pigment epithelium, which interfaces connective tissue at its basal side and neuronal tissue at its apical side.

Teams

Institute of Molecular Pharmacology, Division of Pharmacology in Inflammation, Uniklinik RWTH Aachen

Role of ion channels and ADAM-family metalloproteinases in mechanobiology

Andras Ludwig
Principal Investigator
Alessa Pabst
Doctoral Researcher
Thesis Title
Overview of project B4/C1.  (A) The scheme depictsa 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 R. Merkel; B1) 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.
Institute of Pharmacology and Toxicology, Uniklinik RWTH Aachen

Interaction of the alveolar epithelium and macrophages under mechanical strain

Stefan Uhlig
Principal Investigator
Sarah Bringezu
Doctoral Researcher
Interaction of the Alveolar Epithelium and Macrophages under Mechanical Strain
Overview of project C2. Hypothesis: mechanical ventilation causes cyclic strain that hinders the resolution of alveolar inflammation by inhibiting the conversion of pro-inflammatory M1 (red) into anti-inflammatory M2 (blue) macrophages (MΦ) and influences the interaction of macrophages with the epithelium (grey). Model: Differentiated monolayers of hAELVI cells showing typical epithelial cell-matrix and cell-cell junctions after 14 days of maturation in co-culture with primary human MΦ. Approach: uniaxial and equibiaxial cyclic strain on elastomeric substrates.
Department of Biohybrid & Medical Textiles (BioTex), AME-Institute of Applied Medical Engineering, RWTH Aachen University

Modeling the small airway mucosa in vitro to study mechanobiological effects on tissue remodeling

Stefan Jockenhövel
Principal Investigator
Hannah Kubiza
Doctoral Researcher
Thesis Title
Background and aim of project C3. (A) In vitro tri-culture model of the airway mucosa. PAS and IHC staining presenting an epithelial layer on top and an underlying fibrin gel seeded with endothelial and supporting cells [64]. (B) Induced differentiation and tissue remodeling of the airway mucosa model after exposure to (patho-)physiological mechanical strain (stretch, pressure, compression, stiffness, wall shear stress) and involvement of mechanosensitive channels/mechano-responsive proteins will be investigated.
Interdisciplinary Centre for Clinical Research (IZKF), RWTH Aachen University Hospital

Dissecting the mechanobiological contribution of Bruch’s membrane for the stability of neural retinal adhesion: a bottom-up approach

Jacopo Di Russo
Principal Investigator
Aleksandra Kozyrina
Associated Doctoral Researcher
Thesis Title
Teodora Piskova
Associated Doctoral Researcher
Thesis Title
Vasudha Turukverkere Krishnamurthy
Doctoral Researcher
Thesis Title
Vasudha Turukverkere Krishnamurthy
Doctoral Researcher
Thesis Title
Schematic representation of the approaches in C4. In WP1 we will differentiate photoreceptors from human induced pluripotent stem cells (hiPSC) and combine them with hiPSC-RPE to create a 3D co-culture system for studying RPE-photoreceptor interaction. The use of the Anisogel-containing magnetically-responsive, rod-shaped microgels (green rods) will create a scaffold to support the elongation of the photoreceptor outer segments. In WP2 the effect of BrM cues on RPE adhesion strength to the neurosensory retina will be probed using phantom-photoreceptors microgels (blue rods). The RPE microvilli-induced deformation will be visualized by confocal microscopy and analyzed via finite element modeling.