TREK-1 channels regulate pressure sensitivity and calcium signaling in trabecular meshwork cells

J Gen Physiol. 2018 Dec 3;150(12):1660-1675. doi: 10.1085/jgp.201812179. Epub 2018 Nov 16.


Mechanotransduction by the trabecular meshwork (TM) is an essential component of intraocular pressure regulation in the vertebrate eye. This process is compromised in glaucoma but is poorly understood. In this study, we identify transient receptor potential vanilloid isoform 4 (TRPV4) and TWIK-related potassium channel-1 (TREK-1) as key molecular determinants of TM membrane potential, pressure sensitivity, calcium homeostasis, and transcellular permeability. We show that resting membrane potential in human TM cells is unaffected by "classical" inhibitors of voltage-activated, calcium-activated, and inwardly rectifying potassium channels but is depolarized by blockers of tandem-pore K+ channels. Using gene profiling, we reveal the presence of TREK-1, TASK-1, TWIK-2, and THIK transcripts in TM cells. Pressure stimuli, arachidonic acid, and TREK-1 activators hyperpolarize these cells, effects that are antagonized by quinine, amlodipine, spadin, and short-hairpin RNA-mediated knockdown of TREK-1 but not TASK-1. Activation and inhibition of TREK-1 modulates [Ca2+]TM and lowers the impedance of cell monolayers. Together, these results suggest that tensile homeostasis in the TM may be regulated by balanced, pressure-dependent activation of TRPV4 and TREK-1 mechanotransducers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arachidonic Acid
  • Calcium Signaling*
  • Humans
  • Mechanotransduction, Cellular*
  • Membrane Potentials
  • Middle Aged
  • Potassium Channels, Tandem Pore Domain / physiology*
  • Pressure
  • Primary Cell Culture
  • TRPV Cation Channels / physiology
  • Trabecular Meshwork / cytology
  • Trabecular Meshwork / metabolism*


  • Potassium Channels, Tandem Pore Domain
  • TRPV Cation Channels
  • TRPV4 protein, human
  • potassium channel protein TREK-1
  • Arachidonic Acid