Evidence map›Paper›PMID 25451639›Full record

ArticleFree radical biology & medicine2015

Regulation of iNOS function and cellular redox state by macrophage Gch1 reveals specific requirements for tetrahydrobiopterin in NRF2 activation.

Eileen McNeill, Mark J Crabtree, Natasha Sahgal, Jyoti Patel, Surawee Chuaiphichai, Asif J Iqbal, Ashley B Hale, David R Greaves, Keith M Channon

Open access · hybridAbstract read
In one paragraph

Article in Free radical biology & medicine, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 89 papers.

0numbers the graph read from it
0cells of the map it votes in
89citing papers in PubMed
5.7field-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

89 citing papers in PubMed, 151 citations in OpenAlex.

  1. Article
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  5. Inducible EndothelialHypertension (Dallas, Tex. : 1979) · 2026
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  9. Article
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  12. Review
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  15. Article
  16. Anti-Inflammatory Activity of BiotransformedJournal of microbiology and biotechnology · 2024
    Article
  17. Review
  18. Review
  19. Article
  20. Article

29 more citing papers are in PubMed but not listed here.

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

9 authors at 4 institutions in 1 country.

Eileen McNeillDivision of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
Mark J CrabtreeDivision of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
Natasha SahgalWellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
Jyoti PatelDivision of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
Surawee ChuaiphichaiDivision of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
Asif J IqbalSir William Dunn School of Pathology University of Oxford, Oxford, UK.
Ashley B HaleDivision of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
David R GreavesSir William Dunn School of Pathology University of Oxford, Oxford, UK.
Keith M ChannonDivision of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK. Electronic address: keith.channon@cardiov.ox.ac.uk.
University of Oxford · GBCentre for Human Genetics · GBJohn Radcliffe Hospital · GBBritish Heart Foundation · GB

Funding

British Heart Foundation FS/14/56/31049British Heart Foundation RG/10/15/28578British Heart Foundation RG/12/5/29576Wellcome Trust 090532Wellcome Trust 090532/Z/09/ZWellcome Trust 091504/Z/10/Z
6 · The paper itself

Abstract

Inducible nitric oxide synthase (iNOS) is a key enzyme in the macrophage inflammatory response, which is the source of nitric oxide (NO) that is potently induced in response to proinflammatory stimuli. However, the specific role of NO production, as distinct from iNOS induction, in macrophage inflammatory responses remains unproven. We have generated a novel mouse model with conditional deletion of Gch1, encoding GTP cyclohydrolase 1 (GTPCH), an essential enzyme in the biosynthesis of tetrahydrobiopterin (BH4) that is a required cofactor for iNOS NO production. Mice with a floxed Gch1 allele (Gch1(fl/fl)) were crossed with Tie2cre transgenic mice, causing Gch1 deletion in leukocytes (Gch1(fl/fl)Tie2cre). Macrophages from Gch1(fl/fl)Tie2cre mice lacked GTPCH protein and de novo biopterin biosynthesis. When activated with LPS and IFNγ, macrophages from Gch1(fl/fl)Tie2cre mice induced iNOS protein in a manner indistinguishable from wild-type controls, but produced no detectable NO, as judged by L-citrulline production, EPR spin trapping of NO, and by nitrite accumulation. Incubation of Gch1(fl/fl)Tie2cre macrophages with dihydroethidium revealed significantly increased production of superoxide in the presence of iNOS expression, and an iNOS-independent, BH4-dependent increase in other ROS species. Normal BH4 levels, nitric oxide production, and cellular redox state were restored by sepiapterin, a precursor of BH4 production by the salvage pathway, demonstrating that the effects of BH4 deficiency were reversible. Gch1(fl/fl)Tie2cre macrophages showed only minor alterations in cytokine production and normal cell migration, and minimal changes in basal gene expression. However, gene expression analysis after iNOS induction identified 78 genes that were altered between wild-type and Gch1(fl/fl)Tie2cre macrophages. Pathway analysis identified decreased NRF2 activation, with reduced induction of archetypal NRF2 genes (gclm, prdx1, gsta3, nqo1, and catalase) in BH4-deficient Gch1(fl/fl)Tie2cre macrophages. These findings identify BH4-dependent iNOS regulation and NO generation as specific requirements for NRF2-dependent responses in macrophage inflammatory activation.

Indexed as

AnimalsBiopterinsGTP CyclohydrolaseMacrophagesMiceNF-E2-Related Factor 2Nitric OxideNitric Oxide Synthase Type IIOxidation-ReductionBiopterinsGch1 protein, mouseGTP CyclohydrolaseNfe2l2 protein, mouseNF-E2-Related Factor 2Nitric OxideNitric Oxide Synthase Type IIsapropterinAs3MTBH4GCH1GTPCHiNOSMacrophageNitric oxideNOS2Tetrahydrobiopterin

Identifiers

PMID25451639
PMCPMC4344222
OpenAlexW1983460652

What OpenQuestion holds

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LicenceCC BY
Read underepoch 390

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.