Abstract
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.
Abstract
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
Footnotes
Conflict of interest: T. Jiang has nothing to disclose.
Conflict of interest: R. Samapati has nothing to disclose.
Conflict of interest: S. Klassen has nothing to disclose.
Conflict of interest: D. Lei has nothing to disclose.
Conflict of interest: V. Jankowski has nothing to disclose.
Conflict of interest: S. Simmons has nothing to disclose.
Conflict of interest: J. Yin has nothing to disclose.
Conflict of interest: C. Arenz has nothing to disclose.
Conflict of interest: A. Dietrich has nothing to disclose.
Conflict of interest: T. Gudermann has nothing to disclose.
Conflict of interest: D. Adam has nothing to disclose.
Conflict of interest: M. Schaefer has nothing to disclose.
Conflict of interest: J. Jankowski has nothing to disclose.
Conflict of interest: V. Flockerzi has nothing to disclose.
Conflict of interest: R. Nüsing has nothing to disclose.
Conflict of interest: S. Uhlig has nothing to disclose.
Conflict of interest: W.M. Kuebler has nothing to disclose.
Support statement: V. Jankowski is supported by Deutsche Forschungsgemeinschaft (DFG) SFB TR-R219 project #322900939 – subproject S-03, INST 948/4S-1 FU6.6. S. Simmons is supported by the German Centre for Cardiovascular Research (DZHK) and the German Foundation for Heart Research (F-09-19). C. Arenz is supported by DFG AR 376/12-2. A. Dietrich is supported by DFG SFB TRR152, project 16 and GRK 2338, project 04. T. Gudermann is supported by DFG SFB TR-R152, project 15 and GRK 2338, project 10. D. Adam is supported by DFG project #125440785 – SFB 877 project B02. M. Schaefer is supported by DFG SFB TR-R152, project 18. J. Jankowski is supported by DFG SFB TR-R219 project #322900939. V. Flockerzi is supported by DFG TRR-152, project 01. S. Uhlig is supported by DFG UH 88/9-1. W.M. Kuebler is supported by DFG KU 1218/9-1, KU 1218/11-1, KU 1218/12-1, SFB TR84 project A02 and project C09, SFB 1449 project B01, SFB 1470 project A04, the German Ministry of Education and Research (BMBF) in the framework of SYMPATH (01ZX1906A) and PROVID (01KI20160A), and the DZHK. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received October 4, 2021.
- Accepted February 17, 2022.
- Copyright ©The authors 2022. For reproduction rights and permissions contact permissions{at}ersnet.org
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