Evidence map›Paper›PMID 23461720›Full record

ArticleBritish journal of pharmacology2013

A GPR18-based signalling system regulates IOP in murine eye.

Meggie D Caldwell, Sherry Shu-Jung Hu, Suresh Viswanathan, Heather Bradshaw, Melanie E M Kelly, Alex Straiker

Open access · bronzeAbstract read
In one paragraph

Article in British journal of pharmacology, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 37 papers.

0numbers the graph read from it
0cells of the map it votes in
37citing papers in PubMed
7.0field-weighted citation impact, top 3% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

37 citing papers in PubMed, 67 citations in OpenAlex.

  1. Article
  2. Review
  3. Review
  4. Therapeutic Potential of Cannabinoids in Glaucoma.Pharmaceuticals (Basel, Switzerland) · 2023
    Review
  5. Review
  6. GPR18-Mediated Relaxation of Human Isolated Pulmonary Arteries.International journal of molecular sciences · 2022
    Article
  7. Article
  8. Article
  9. Review
  10. Cannabidiol Signaling in the Eye and Its Potential as an Ocular Therapeutic Agent.Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology · 2021
    Article
  11. Article
  12. Article
  13. Article
  14. Article
  15. Article
  16. Article
  17. GPR55 deficiency is associated with increased adiposity and impaired insulin signaling in peripheral metabolic tissues.FASEB journal : official publication of the Federation of American Societies for Experimental Biology · 2019
    Article
  18. Article
  19. Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 3 institutions in 3 countries.

Meggie D CaldwellDepartment of Clinical Vision Science, Dalhousie University, Halifax, NS, Canada.
Sherry Shu-Jung Hu
Suresh Viswanathan
Heather Bradshaw
Melanie E M Kelly
Alex Straiker
Indiana University Bloomington · USDalhousie University · CANational Cheng Kung University · TW

Funding

Microglial activation by N-arachidonoyl glycineR21DA032150 · NIDA · TRUSTEES OF INDIANA UNIVERSITY · PI BRADSHAW, HEATHER BRYTE · 2011 to 2012
$424k
GPR119: A novel means to lower intraocular pressure?R21EY021831 · NEI · TRUSTEES OF INDIANA UNIVERSITY · PI STRAIKER, ALEXANDER J · 2011 to 2012
$424k
Identification and characterization of two novel cannabinoid receptorsR21DA024122 · NIDA · TRUSTEES OF INDIANA UNIVERSITY · PI STRAIKER, ALEXANDER J · 2007 to 2008
$299k
CIHR FRN 97768NEI NIH HHS EY021831NEI NIH HHS R21 EY021831NIDA NIH HHS DA24122NIDA NIH HHS R21 DA024122NIDA NIH HHS R21 DA032150
6 · The paper itself

Abstract

background and purposeGPR18 is a recently deorphaned lipid receptor that is activated by the endogenous lipid N-arachidonoyl glycine (NAGly) as well the behaviourally inactive atypical cannabinoid, abnormal cannabidiol (Abn-CBD). The presence and/or function of any GPR18-based ocular signalling system remain essentially unstudied. The objectives of this research are: (i) to determine the disposition of GPR18 receptors and ligands in anterior murine eye, (ii) examine the effect of GPR18 activation on intraocular pressure (IOP) in a murine model, including knockout mice for CB₁, CB₂ and GPR55. EXPERIMENTAL APPROACH: IOP was measured in mice following topical application of Abn-CBD, NAGly or the GPR55/GPR18 agonist O-1602, alone or with injection of the GPR18 antagonist, O-1918. GPR18 protein localization was assessed with immunohistochemistry. Endocannabinoids were measured using LC/MS-MS. KEY

resultsGPR18 protein was expressed most prominently in the ciliary epithelium and the corneal epithelium and, interestingly, in the trabecular meshwork. The GPR18 ligand, NAGly, was also detected in mouse eye at a level comparable to that seen in the brain. Abn-CBD and NAGly, but not O-1602, significantly reduced IOP in all mice tested. The antagonist, O-1918, blocked the effects of Abn-CBD and NAGly. CONCLUSIONS AND IMPLICATIONS: We present evidence for a functional GPR18-based signalling system in the murine anterior eye, including receptors and ligands. GPR18 agonists, Abn-CBD and NAGly, reduce IOP independently of CB₁, CB₂ or GPR55. These findings suggest that GPR18 may serve as a desirable target for the development of novel ocular hypotensive medications.

Indexed as

Intraocular PressureSignal TransductionAdministration, OphthalmicAnimalsAnterior Eye SegmentArachidonic AcidsCannabinoid Receptor AgonistsCannabinoid Receptor AntagonistsCiliary BodyEndocannabinoidsEpithelium, CornealEye ProteinsGlycineLigandsMaleMice4-(3-3,4-p-menthadien-(1,8)-yl)olivetolArachidonic AcidsCannabinoid Receptor AgonistsCannabinoid Receptor AntagonistsCNR1 protein, mouseCnr2 protein, mouseEndocannabinoidsEye ProteinsGlycineGPR18 protein, mouseGPR55 protein, mouseLigandsN-arachidonylglycineReceptor, Cannabinoid, CB1Receptor, Cannabinoid, CB2Receptors, CannabinoidReceptors, G-Protein-CoupledResorcinols

Identifiers

PMID23461720
PMCPMC3687663
OpenAlexW1670044449

What OpenQuestion holds

Textmetadata
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.