RT Journal Article
SR Electronic
T1 Stimulation of the EP<sub>3</sub> receptor causes lung oedema by activation of TRPC6 in pulmonary endothelial cells
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 2102635
DO 10.1183/13993003.02635-2021
VO 60
IS 4
A1 Tian Jiang
A1 Rudi Samapati
A1 Sergej Klassen
A1 Disi Lei
A1 Lasti Erfinanda
A1 Vera Jankowski
A1 Szandor Simmons
A1 Jun Yin
A1 Christoph Arenz
A1 Alexander Dietrich
A1 Thomas Gudermann
A1 Dieter Adam
A1 Michael Schaefer
A1 Joachim Jankowski
A1 Veit Flockerzi
A1 Rolf Nüsing
A1 Stefan Uhlig
A1 Wolfgang M. Kuebler
YR 2022
UL http://erj.ersjournals.com/content/60/4/2102635.abstract
AB Background Prostaglandin E2 (PGE2) increases pulmonary vascular permeability by activation of the PGE2 receptor 3 (EP3), which may explain adverse pulmonary effects of the EP1/EP3 receptor agonist sulprostone in patients. In addition, PGE2 contributes to pulmonary oedema in response to platelet-activating factor (PAF). PAF increases endothelial permeability by recruiting the cation channel transient receptor potential canonical 6 (TRPC6) to endothelial caveolae via acid sphingomyelinase (ASMase). Yet, the roles of PGE2 and EP3 in this pathway are unknown. We hypothesised that EP3 receptor activation may increase pulmonary vascular permeability by activation of TRPC6, and thus, synergise with ASMase-mediated TRPC6 recruitment in PAF-induced lung oedema.Methods In isolated lungs, we measured increases in endothelial calcium (ΔCa2+) or lung weight (Δweight), and endothelial caveolar TRPC6 abundance as well as phosphorylation.Results PAF-induced ΔCa2+ and Δweight were attenuated in EP3-deficient mice. Sulprostone replicated PAF-induced ΔCa2+ and Δweight which were blocked by pharmacological/genetic inhibition of TRPC6, ASMase or Src-family kinases (SrcFK). PAF, but not sulprostone, increased TRPC6 abundance in endothelial caveolae. Immunoprecipitation revealed PAF- and sulprostone-induced tyrosine-phosphorylation of TRPC6 that was prevented by inhibition of phospholipase C (PLC) or SrcFK. PLC inhibition also blocked sulprostone-induced ΔCa2+ and Δweight, as did inhibition of SrcFK or inhibitory G-protein (Gi) signalling.Conclusions EP3 activation triggers pulmonary oedema via Gi-dependent activation of PLC and subsequent SrcFK-dependent tyrosine phosphorylation of TRPC6. In PAF-induced lung oedema, this TRPC6 activation coincides with ASMase-dependent caveolar recruitment of TRPC6, resulting in rapid endothelial Ca2+ influx and barrier failure.EP3 activation triggers pulmonary oedema via Gi-dependent activation of PLC and subsequent tyrosine phosphorylation of TRPC6. In PAF-induced lung oedema this TRPC6 activation coincides with ASMase-dependent caveolar recruitment of TRPC6. https://bit.ly/34P3d13