Third party funded individual grant
Start date : 01.01.2018
End date : 31.12.2019
Mechanical signaling is a fundamental mechanism of cell-environment interaction and is sensed by cellular mechano-biosensors to be transformed into cellular remodeling of shape and connectivity with the surrounding tissue matrix. This involves mechanosensors, such as mechanosensitive ion channels, but also intracellular strain dissipation elements of the cytoskeleton. On the effector side, cellular anchorage with the surrounding matrix is established via focal adhesion complex (FAC) molecules, such as integrins and vinculin, which are fundamentally conserved in many tissues. In particular in the cardiovascular system, mechanical strain is a permanent companion, as the heart is compressed and dilated on a beat-to-beat basis. Thus, endothelial, vascular and cardiac myocytes experience varying strain-stress profiles that must be decoded and translated into FAC remodeling to respond to overt stress, e.g. in pathological conditions. Since stretch in hollow organs is multidirectional, technologies to mimic such complex strain profiles are urgently needed and only scarcely available on the market. We recently developed a so-called IsoStretcher to apply isotropic strain profiles to cells adhered on elastomer substrates or embedded in hydrogels for live-cell imaging in mechanobiology.
Among the very recently new mechano-sensors in mammals is the family of Piezo-proteins that represent ‘force-from-lipids’ biosensors of membrane strain or bending. Although there has been very recent novel information on Piezo channels in migratory action of immune or tumor cells, and expression in the cardiovascular system has been confirmed, their function and biophysical role in cellular mechanosensing and cellular remodeling, in particular in the heart, is totally unclear.
This international collaborative project is a continuation of a very successful, DAAD-funded liaison and will involve novel state-of-the art bioengineered technology to address the following scientific goals:
1) To determine and characterize stretch-induced Ca2+ entry and FAC remodeling in Piezo-1 overexpressing HEK293 cells coated on polydimethylsiloxane substrates and isotropically stretched with IsoStretcher technology for various durations (short, long-term).
2) To determine stretch-induced Ca2+ entry and FAC remodeling in ventricular murine cardiomyocytes (CM) embedded in porous polyvinyl-alcohol hydrogels and stretched isotropically (IsoStretcher) for various durations
3) To delineate the contribution of mechanosensitive channels (MSC) from intracellular cytoskeleton in mechanosensing by application of channel blockers and depolymerisation of cytoskeletal components
To screen for novel organic compounds potent to block Piezo-1 proteins (ferrocene, trioxanes, marine compounds, etc.)