Evidence map›Paper›PMID 34184090›Full record

ArticleMolecular medicine reports2021

Nuclear PKR in retinal neurons in the early stage of diabetic retinopathy in streptozotocin‑induced diabetic rats.

Viviane Aline Oliveira Silva, Nayara Delgado André, Thaís Amaral E Sousa, Vâni Maria Alves, Isis Do Carmo Kettelhut, Fernando Luiz De Lucca

Open access · bronzeAbstract read
In one paragraph

Article in Molecular medicine reports, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
0.6field-weighted citation impact, top 36% 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

2 citing papers in PubMed, 7 citations in OpenAlex.

  1. Review
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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 4 institutions in 1 country.

Viviane Aline Oliveira SilvaMolecular Oncology Research Center, Barretos Cancer Hospital, Barretos, São Paulo 14784‑400, Brazil.
Nayara Delgado AndréUniversity of São João Del Rei, Divinópolis, Minas Gerais 35501‑296, Brazil.
Thaís Amaral E SousaFederal Institute of Education, Science and Technology of Goiás, Formosa, Goiás 73813‑816, Brazil.
Vâni Maria AlvesDepartment of Biochemistry and Immunology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo 14049‑900, Brazil.
Isis Do Carmo KettelhutDepartment of Biochemistry and Immunology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo 14049‑900, Brazil.
Fernando Luiz De LuccaDepartment of Biochemistry and Immunology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo 14049‑900, Brazil.
Universidade de São Paulo · BRFederal University of São João del-Rei · BRHospital de Câncer de Barretos · BRInstituto Federal de Goiás · BR

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Retinal neuron apoptosis is a key component of diabetic retinopathy (DR), one of the most common complications of diabetes. Stress due to persistent hyperglycaemia and corresponding glucotoxicity represents one of the primary pathogenic mechanisms of diabetes and its complications. Apoptosis of retinal neurons serves a critical role in the pathogenesis of DR observed in patients with diabetes and streptozotocin (STZ)‑induced diabetic rats. Retinal neuron apoptosis occurs one month after STZ injection, which is considered the early stage of DR. The molecular mechanism involved in the suppression of retinal neuron apoptosis during the early stage of DR remains unclear. RNA‑dependent protein kinase (PKR) is a stress‑sensitive pro‑apoptotic kinase. Our previous study indicated that PKR‑associated protein X, a stress‑sensitive activator of PKR, is upregulated in the early stage of STZ‑induced diabetes. In order to assess the role of PKR in DR prior to apoptosis of retinal neurons, immunofluorescence and western blotting were performed to investigate the cellular localization and expression of PKR in the retina in the early stage of STZ‑induced diabetes in rats. PKR activity was indirectly assessed by expression levels of phosphorylated eukaryotic translation initiation factor 2α (p‑eIF2‑α) and the presence of apoptotic cells in the retina was investigated by TUNEL assay. The findings revealed that PKR was localized in the nucleus of retinal ganglion and inner nuclear layer cells from normal and diabetic rats. To the best of our knowledge, the present study is the first to demonstrate nuclear localization of PKR in retinal neurons. Immunofluorescence analysis demonstrated that PKR was expressed in the nuclei of retinal neurons at 3 and 6 days and its expression was decreased at 15 days after STZ treatment. In addition, p‑eIF2‑α expression and cellular localization followed the trend of PKR, suggesting that this pro‑apoptotic kinase was active in the nuclei of retinal neurons. These findings are consistent with the hypothesis that nuclear translocation of PKR may be a mechanism to sequester active PKR, thus preventing upregulation of cytosolic signalling pathways that induce apoptosis in retinal neurons. Apoptotic cells were not detected in the retina in the early stage of DR. A model was proposed to explain the mechanism by which apoptosis of retinal neurons by PKR is suppressed in the early stage of DR. The possible role of mitochondrial RNA (mtRNA) and

Indexed as

AnimalsApoptosisDiabetes Mellitus, ExperimentalDiabetic RetinopathyDown-RegulationeIF-2 KinaseEukaryotic Initiation Factor-2MaleRatsRats, WistarRetinal NeuronsStreptozocineIF-2 KinaseEukaryotic Initiation Factor-2Streptozocinapoptosisdiabetic retinopathynuclear PKRretinal neuron

Identifiers

PMID34184090
PMCPMC8258468
OpenAlexW3175084873

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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.