Prolonged glutamate excitotoxicity increases GluR1 immunoreactivity but decreases mRNA of GluR1 and associated regulatory proteins in dissociated rat retinae in vitro

Challenor, Michael; Doig, Ryan O'Hare; Fuller, Paula I.; Giacci, Marcus K.; Bartlett, Carole A.; Wale, Celeste H.; Cozens, Greg; Hool, Livia C.; Dunlop, Sarah; Iyer, K. Swaminathan; Rodger, Jennifer; Fitzgerald, Maria

doi:10.1016/j.biochi.2015.03.008

Cited by 11 publications

(6 citation statements)

References 107 publications

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“…Similar results have been found by others studying glutamate receptor activity in the rat retina, where improper regulation of the GluR1 AMPA receptor subunit and other associated proteins had low mRNA levels, high protein levels, and increased reactive oxygen species associated with excitotoxicity and cell death (Challenor et al, 2015). Therefore, aberrant Fyn protein expression levels could be a result of misregulation of a protein that modifies Fyn activity, such as STEP (Boehm, 2013; Kaufman et al, 2015; Nygaard et al, 2014).…”

Section: Discussionsupporting

confidence: 88%

Regulatory region genetic variation is associated with FYN expression in Alzheimer's disease

Zahratka

Shao

Shaw

et al. 2017

Neurobiology of Aging

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Neurofibrillary tangles (NFTs), composed of hyperphosphorylated tau, are a key pathologic feature of Alzheimer’s disease (AD). Tau phosphorylation is under the control of multiple kinases and phosphatases, including Fyn. Previously, our group found an association between two regulatory single nucleotide polymorphisms (SNPs) in the FYN gene with increased tau levels in the CSF. In this study, we hypothesized that Fyn expression in the brain is influenced by AD status and genetic content. We found that Fyn protein, but not mRNA, levels were increased in AD patients compared to cognitively normal controls and are associated with regulatory region SNPs. Additionally, expression of the FYN 3’ UTR can decrease expression in multiple cell lines, suggesting this regulatory region plays an important role in FYN expression. Taken together, these data suggest that FYN expression is regulated according to AD status and regulatory region haplotype, and genetic variants may be instrumental in the development of NFTs in AD and other tauopathies.

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Section: Discussionsupporting

confidence: 88%

Regulatory region genetic variation is associated with FYN expression in Alzheimer's disease

Zahratka

Shao

Shaw

et al. 2017

Neurobiology of Aging

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“…87 The difference in the observations between mRNA levels and protein levels of GLUA1-4, suggest changes in expression levels for mRNA and protein may be transient and difficult to pinpoint. It also is possible that protein expression of AMPAR subunits may not correlate with mRNA expressions 88 at early time points, where AMPAR are constantly cycled from reserve pools of intracellular vesicles. 89,90 AMPAR are permeable to Na þ and K þ ions, whereas the permeability to Ca 2þ is dependent on the integration of GLUA2 subunits into the receptors.…”

Section: Discussionmentioning

confidence: 99%

Involvement of AMPA Receptor and Its Flip and Flop Isoforms in Retinal Ganglion Cell Death Following Oxygen/Glucose Deprivation

Park

Broyles

et al. 2016

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. The a-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptors (AMPAR) subunits can be posttranscriptionally modified by alternative splicing forming flip and flop isoforms. We determined if an ischemia-like insult to retinal ganglion cells (RGCs) increases AMPAR susceptibility to s-AMPA-mediated excitotoxicity through changes in posttranscriptional modified isoforms. METHODS.Purified neonatal rat RGCs were subjected to either glucose deprivation (GD) or oxygen/glucose deprivation (OGD) conditions followed by treatment with either 100 lM s-AMPA or Kainic acid. A live-dead assay and caspase 3 assay was used to assess cell viability and apoptotic changes, respectively. We used JC-1 dye and dihydroethidium to measure mitochondria depolarization and reactive oxygen species (ROS), respectively. Calcium imaging with fura-2AM was used to determine intracellular calcium, while the fluorescentlylabeled probe, Nanoprobe1, was used to detect calcium-permeable AMPARs. Quantitative PCR (qPCR) analysis was done to determine RNA editing sites AMPAR isoforms.RESULTS. Glucose deprivation, as well as an OGD insult followed by AMPAR stimulation, produced a significant increase in RGC death. Retinal ganglion cell death was independent of caspase 3/7 activity, but was accompanied by increased mitochondrial depolarization and increased ROS production. This was associated with an elevated intracellular Ca 2þ and calcium permeable-AMPARs. The mRNA expression of GLUA2 and GLUA3 flop isoform decreased significantly, while no appreciable changes were found in the corresponding flip isoforms. There were no changes in the Q/R editing of GLUA2, while R/G editing of GLUA2 flop declined under these conditions. CONCLUSIONS. Following oxidative injury, RGCs become more susceptible to AMPAR-mediated excitotoxicity. RNA editing and changes in alternative spliced flip and flop isoforms of AMPAR subunits may contribute to increased RGC death.

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“…* and ¥ correspond to RE1 sequences previously reported by Kashiwagi et al (2012) [ 18 ] and Schoenherr et al (1996) [ 19 ], respectively, while ± corresponds to RE1 sequences reported in this study. ( B ) List of oligonucleotides used in this study [ 20 , 21 , 22 , 23 , 24 ]. F: Forward; R: Reverse.…”

Section: Figurementioning

confidence: 99%

“…F: Forward; R: Reverse. * Oligonucleotides used in this study; Oligonucleotides reported by: Ortuño-Pineda et al, [ 3 ]; α Chteinberg et al, 2018 [ 20 ]; β Janitzky et al, 2014 [ 21 ]; + Bo et al, 2014 [ 22 ]; λ Challenor et al, 2015 [ 23 ]; Wang et al, 2015 [ 24 ] ( C ) REST silencing and RT–PCR of the REST targets. The upper panel labeled WB corresponds to Western blot for REST, and the lower panel corresponds to RT–PCR for REST target genes.…”

Section: Figurementioning

confidence: 99%

REST/NRSF Silencing Modifies Neuronal Gene Expression in siRNA-Treated HeLa Cells: A Preliminary Exploration in the Search for Neuronal Biomarkers of Cervical Cancer

et al. 2023

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Background and Objectives: REST (RE1-silencing transcription factor) diminution is associated with transcriptional relaxation, neuropeptide overexpression, and phenotype redefinition in neuroendocrine cancers, but this effect has barely been studied in cervical cancer (CC). We previously reported reduced expressions of REST in samples with premalignant lesions and CC; however, the transcriptional consequences for neural genes associated with reduced REST expression in CC are unknown. Therefore, the objective of this work was to evaluate the expression of neuronal genes in cancerous cells with reduced expression levels of REST. Materials and Methods: Here, we monitored levels of REST by immunostaining along the premalignant lesions and in invasive cervical squamous cell carcinoma (SCC) and endocervical adenocarcinoma (ADC) in tissue samples from female patients from southern Mexico and the derivative cell lines SiHa and HeLa, respectively. Next, we selected REST target genes in silico and explored the effect of REST silencing by RT-PCR in siRNA-treated HeLa cells. Results: The results show a REST diminution in premalignant lesions, SCC, ADC, and cancerous cell lines. Further REST silencing in HeLa cells altered the expression of genes containing the RE1 (Restrictive Element 1) sequence, including CgA (chromogranin A), CHRNβ2 (cholinergic receptor nicotinic β 2 subunit), BDNF (brain-derived neurotrophic factor), CRF (corticotropin-releasing factor), and RASSF1A (Ras association domain family 1). Conclusions: This work provides preliminary evidence of the role of REST loss in the transcriptional regulation of its target genes in HeLa cells, which could have positive implications for the search for new biomarkers of cervical cancer.

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Prolonged glutamate excitotoxicity increases GluR1 immunoreactivity but decreases mRNA of GluR1 and associated regulatory proteins in dissociated rat retinae in vitro

Cited by 11 publications

References 107 publications

Regulatory region genetic variation is associated with FYN expression in Alzheimer's disease

Regulatory region genetic variation is associated with FYN expression in Alzheimer's disease

Involvement of AMPA Receptor and Its Flip and Flop Isoforms in Retinal Ganglion Cell Death Following Oxygen/Glucose Deprivation

REST/NRSF Silencing Modifies Neuronal Gene Expression in siRNA-Treated HeLa Cells: A Preliminary Exploration in the Search for Neuronal Biomarkers of Cervical Cancer

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