Evidence map›Paper›PMID 39211001›Full record

ArticleFrontiers in ophthalmology2024

Time of day differences in the regulation of glutathione levels in the rat lens.

Bo Li, Haruna Suzuki-Kerr, Renita M Martis, Christopher J J Lim, Zhou-Ai Wang, Tai X Nguyen, Paul J Donaldson, Raewyn C Poulsen, Julie C Lim

Abstract read
In one paragraph

Article in Frontiers in ophthalmology, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
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

1 citing paper in PubMed.

  1. 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

9 authors.

Bo LiDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Haruna Suzuki-KerrDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Renita M MartisDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Christopher J J LimDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Zhou-Ai WangDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Tai X NguyenDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Paul J DonaldsonDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Raewyn C PoulsenDepartment of Pharmacology, University of Auckland, Auckland, New Zealand.
Julie C LimDepartment of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Evidence in non-ocular tissues indicate that the antioxidant glutathione (GSH) may be regulated in a circadian manner leading to the idea that GSH levels in the lens may also be controlled in a circadian manner to anticipate periods of oxidative stress. Methods: Male rat Wistar lenses (6 weeks) were collected every 4 hours over a 24-hour period at 6am, 10am, 2pm, 6pm, 10pm and 2am and quantitative-PCR, western blotting and immunohistochemistry performed to examine the expression of core clock genes and proteins (BMAL1, CLOCK, CRY1-2, PER 1-3) and their subcellular localisation over a 24-hour period. Western blotting of lenses was also performed to examine the expression of NRF2, a transcription factor involved in regulating genes involved in GSH homeostasis and GSH related enzymes (GCLC, GS and GR) over the 24-hour period. Finally, HLPC was used to measure GSH levels in the aqueous humour and lenses every 4 hours over a 24-hour period. Results: The rat lens contains the core molecular components of a circadian clock with the expression of core clock proteins, NRF2 and GSH related enzymes fluctuating over a 24-hour period. BMAL1 expression was highest during the day, with BMAL1 localised to the nuclei at 10am. NRF2 expression remained constant over the 24-hour period, although appeared to move in and out of the nuclei every 4 hours. GSH related enzyme expression tended to peak at the start of night which correlated with high levels of GSH in the lens and lower levels of GSH in the aqueous humour. Conclusion: The lens contains the key components of a circadian clock, and time-of-day differences exist in the expression of GSH and GSH related enzymes involved in maintaining GSH homeostasis. GSH levels in the rat lens were highest at the start of night which represents the active phase of the rat when high GSH levels may be required to counteract oxidative stress induced by cellular metabolism. Future work to directly link the clock to regulation of GSH levels in the lens will be important in determining whether the clock can be used to help restore GSH levels in the lens.

Indexed as

antioxidantcircadian clockglutathionelensNRF2

Identifiers

PMID39211001
PMCPMC11358124

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