Emergent temporal signaling in human trabecular meshwork cells: role of TRPV4-TRPM4 interactions
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Published version
Author(s)
Yarishkin, Oleg
Phuong, Tam TT
Vazquez-Chona, Felix
Bertrand, Jacques
van Battenburg-Sherwood, Joseph
Type
Journal Article
Abstract
Trabecular meshwork (TM) cells are phagocytic cells that employ mechanotransduction to actively regulate intraocular pressure. Similar to macrophages, they express scavenger receptors and participate in antigen presentation within the immunosuppressive milieu of the anterior eye. Changes in pressure deform and compress the TM, altering their control of aqueous humor outflow but it is not known whether transducer activation shapes temporal signaling. The present study combines electrophysiology, histochemistry and functional imaging with gene silencing and heterologous expression to gain insight into Ca2+ signaling downstream from TRPV4 (Transient Receptor Potential Vanilloid 4), a stretch-activated polymodal cation channel. Human TM cells respond to the TRPV4 agonist GSK1016790A with fluctuations in intracellular Ca2+ concentration ([Ca2+]i) and an increase in [Na+]i. [Ca2+]i oscillations coincided with monovalent cation current that was suppressed by BAPTA, Ruthenium Red and the TRPM4 (Transient Receptor Potential Melastatin 4) channel inhibitor 9-phenanthrol. TM cells expressed TRPM4 mRNA, protein at the expected 130-150 kDa and showed punctate TRPM4 immunoreactivity at the membrane surface. Genetic silencing of TRPM4 antagonized TRPV4-evoked oscillatory signaling whereas TRPV4 and TRPM4 co-expression in HEK-293 cells reconstituted the oscillations. Membrane potential recordings suggested that TRPM4-dependent oscillations require release of Ca2+ from internal stores. 9-phenanthrol did not affect the outflow facility in mouse eyes and eyes from animals lacking TRPM4 had normal intraocular pressure. Collectively, our results show that TRPV4 activity initiates dynamic calcium signaling in TM cells by stimulating TRPM4 channels and intracellular Ca2+ release. It is possible that TRPV4-TRPM4 interactions downstream from the tensile and compressive impact of intraocular pressure contribute to homeostatic regulation and pathological remodeling within the conventional outflow pathway.
Date Issued
2022-03-31
Date Acceptance
2022-03-02
Citation
Frontiers in Immunology, 2022, 13, pp.1-15
ISSN
1664-3224
Publisher
Frontiers Media
Start Page
1
End Page
15
Journal / Book Title
Frontiers in Immunology
Volume
13
Copyright Statement
Copyright © 2022 Yarishkin, Phuong, Vazquez-Chona, Bertrand, van Battenburg-Sherwood, Redmon, Rudzitis, Lakk, Baumann, Freichel, Hwang, Overby and Križaj. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
License URL
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000788681100001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Subjects
Science & Technology
Life Sciences & Biomedicine
Immunology
Trabecular meshwork
TRPV4
TRPM4
calcium oscillations
glaucoma
conventional outflow facility
GSK1016790
immune
NONSELECTIVE CATION CHANNEL
OPERATED CALCIUM-ENTRY
INTRAOCULAR-PRESSURE
TRPV4 CHANNEL
RECEPTOR 4
9-PHENANTHROL
OSCILLATIONS
HOMEOSTASIS
ACTIVATION
Publication Status
Published
Article Number
ARTN 805076
Date Publish Online
2022-03-31