Oral Presentation 2014 International Biophysics Congress

Transactivation of TRPV4 by GPCR activation, hypotonic stress and shear stress (#97)

Peter McIntyre 1
  1. RMIT University, Bundoora, VIC, Australia

Mechanical sensation is important in a range of mammalian systems, including hearing, touch, osmotic homeostasis and regulation of blood flow. Mechano-sensitive cellular activation mechanisms play an important sensory role in neuronal, epithelial and endothelial cells. Whilst much is known about bacterial mechanosensation and the ion channels that mediate it, comparatively little is known about the mammalian sensors and ion channels. Several candidate mammalian ion channels have been identified, including Piezo channels, two-pore potassium (K2P) channels and ENaC channels. The TRP non specific cation channels, TRPC6 and TRPV4 have been implicated and they are ideally suited to trigger signaling because of their high calcium permeability and ability to depolarize cells. In the present study, we have investigated mechanical activation of TRPV4. TRPV4 opens in response to shear stress and hypo-osmolarity in HEK293 cells and vascular endothelial cells. We find that signaling to TRPV4 plays a crucial role in the opening this ion channel in response to mechanical stimulation, hypotonic stress and activation of some GPCRs. Shear stress can potentiate the TRPV4 response the agonist GSK1016790A and this effect is dependent on the membrane translocation of TRPV4.