Glutamate activation of Oct-2 in cultured chick Bergmann glia cells: Involvement of NFκB

Méndez, José Alfredo Tirado; López-Bayghen, Esther; Ortega, Arturo

doi:10.1002/jnr.20519

Cited by 4 publications

(10 citation statements)

References 64 publications

(90 reference statements)

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“…On the other hand, in BGC, the construct was not responsive either to Glu or to the overexpression of Oct‐1 or Oct‐2 isoforms, marking a sharp contrast between these two radial glial cell types. Additional elements may be needed for Oct‐2 to fully repress transcriptional activity under Glu treatment in BGC, as we have already reported for the chkbp promoter (Mendez et al . 2005).…”

Section: Resultsmentioning

confidence: 66%

“…We have recently reported that Oct‐1 and Oct‐2 are present in cultured BGC from chick cerebellum. Interestingly, following Glu receptor stimulation, Oct‐2 is activated and down‐regulates the chkbp promoter (Mendez et al . 2004, 2005).…”

Section: Resultsmentioning

confidence: 99%

“…Interestingly, the three iGluR subtypes are expressed and mediate multiple signaling events in both cell types (Lopez et al 1994(Lopez et al , 1998Lopez-Colome et al 1995. For instance, in BGC, AMPA receptor activation mediates transcriptional responses effected through transcription factors such as the activator protein-1 (AP-1), the cAMP response-element binding protein (CREB), the inducible nuclear factor kappa B (NF-jB) dimer and POU domain proteins (Pit-1, Oct-1 and Oct-2, Unc86) (Sanchez and Ortega 1994;Lopez-Colome et al 1995;Aguirre et al 2000;Mendez et al 2004Mendez et al , 2005. These factors are activated and modulate gene expression after Glu exposure; for example, Fos and Jun are involved in kainate binding protein (KBP) and Na + -dependent glutamate/aspartate transporter (GLAST) transcriptional regulation (Aguirre et al 2000(Aguirre et al , 2002Espinoza-Rojo et al 2000;Lopez-Bayghen et al 2003a;Lopez-Bayghen et al 2003b;Lopez-Bayghen and Ortega 2004).…”

mentioning

confidence: 99%

“…Neuronal isoforms, like Oct-2.5, are typically repressors Lillycrop et al 1991). In BGC, activation of Oct-2 by glutamate through AMPA receptor activation negatively regulates the chkbp promoter via a signaling pathway that includes protein kinase C (PKC) and NF-jB (Mendez et al 2005).…”

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confidence: 99%

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Glutamate‐induced octamer DNA binding and transcriptional control in cultured radial glia cells

López-Bayghen

Cruz-Solis

Corona

et al. 2006

Journal of Neurochemistry

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Glutamate, the main excitatory neurotransmitter in the vertebrate brain, is critically involved in gene expression regulation in neurons and in glia cells. Neuron-glia interactions provide the framework for synaptic plasticity. Retinal and cerebellar radial glia cells surround glutamatergic excitatory synapses and sense synaptic activity through glutamate receptors expressed in their membranes. Several glutamatedependent membrane to nuclei signaling cascades have been described in these cells. Octamer DNA binding factors, namely Oct-1 and Oct-2 recognize similar DNA sequences on regulatory regions, but their final transcriptional effect depends on several factors. By these means, different responses can be achieved in different cell types. Here, we describe a comparison between the glutamate-induced DNA binding of octamer factors and their functional activities in two important types of radial glia, retinal Mü ller and cerebellar Bergmann glial cells. While Oct-1 is expressed in both cell types and in both glutamate treatments results in an increase in Oct-1 DNA binding, this complex is capable of transactivating a reporter gene only in Mü ller glia cells. In contrast, Oct-2 expression is restricted to Bergmann glia cells in which glutamate treatment results in an augmentation of Oct-2 DNA binding complexes and the repression of kainate binding protein gene transcription. Our present findings demonstrate a differential role for Oct-1 and Oct-2 transcription factors in glial glutamate signaling, and further strengthen the notion of an important role for glial cells in glutamatergic transactions in the central nervous system.

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Section: Resultsmentioning

confidence: 66%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Glutamate‐induced octamer DNA binding and transcriptional control in cultured radial glia cells

López-Bayghen

Cruz-Solis

Corona

et al. 2006

Journal of Neurochemistry

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“…The reorganization of the actin cytoskeleton depends on PI3-K, FAK, PKC, and external calcium The activation of RhoA requires the interchange of the bound GDP for GTP, this is carried out by the GEFs. Activation of Bergmann glia AMPA receptors triggers signal pathways, that in the short time include PI3-K (Millan et al 2004), FAK (Millan et al 2001(Millan et al , 2004 and PKC (Mendez et al 2005), Fig. 3 The reorganization of the actin cytoskeleton of Bergmann fibers depends on alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors and RhoA.…”

Section: Rhoa Modulates the Actin Cytoskeleton In Bergmann Fibersmentioning

confidence: 99%

AMPA receptors modulate the reorganization of F‐actin in Bergmann glia cells through the activation of RhoA

Rosas‐Hernández¹,

Bastián

Tello³

et al. 2019

Journal of Neurochemistry

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Alpha‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid glutamate receptors have been shown to modulate the morphology of the lamelar processes of Bergmann glia cells in the molecular layer of the cerebellum. Here we suggest that reorganization of F‐actin may underlay the changes in the morphology of the lamelar processes. Using the fluorescent staining of F‐actin with Phalloidin and the quantification of RhoA activation through immunoprecipitation or pull‐down assays, we show that RhoA is activated after stimulation of alpha‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid receptors and leads to the reorganization of the actin cytoskeleton of Bergmann fibers. This reorganization of the actin cytoskeleton is reflected in the form of an increase in the intensity of the F‐actin staining as well as in the loss of the number of Bergmann fibers stained with Phalloidin. Moreover, using a pharmacological approach, we show that activation of RhoA and the change in the intensity of the F‐actin staining depends on the activation of PI3‐K, focal adhesion kinase, and protein kinase C, whereas changes in the number of Bergmann fibers depend on external calcium in a RhoA independent manner. Our findings show that glutamate may induce a form of structural plasticity in Bergmann glia cells through the reorganization of the actin cytoskeleton. This may have implications in the way the synaptic transmission is processed in the cerebellum.

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An Acute Glutamate Exposure Induces Long-Term Down Regulation of GLAST/EAAT1 Uptake Activity in Cultured Bergmann Glia Cells

et al. 2013

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Glutamate, the major excitatory neurotransmitter in the vertebrate brain, is a potent neurotoxin therefore its extracellular levels have to be tightly regulated by means of sodium-dependent glutamate uptake systems of the slc1A family. The glial glutamate/aspartate transporter (GLAST/EAAT1) and the glutamate transporter 1 carry most of the uptake activity in cerebellum and in the forebrain, respectively. In the cerebellar cortex, GLAST is profusely expressed in Bergmann glia cells, which completely enwrap the parallel fiber-Purkinje cells synapses. Glutamate exposure in these cells, down regulates the activity as well as the expression levels of this transporter. In order to characterize the persistence of a single glutamate exposure, we followed the [(3)H]-D-aspartate uptake activity as a function of time after the removal of the glutamatergic stimulus. We were able to demonstrate that a single 30 min exposure to glutamate reduces the uptake activity for up to 3 h. This effect is dose-dependent and it is not reproduced neither by ionotropic nor metabotropic glutamate receptors agonists. In contrast, transporter specific ligands such as D-aspartate or L-(-)-threo-3-Hydroxyaspartic acid fully reproduce the glutamate effect. Equilibrium binding experiments revealed a decrease in [(3)H]-D-aspartate Bmax without a significant change in affinity, clearly suggesting that a reduction in the availability of plasma membrane glutamate transporters is the molecular basis of this effect. Interestingly, neither Glast mRNA nor its protein levels were significantly reduced upon the single glutamate exposure. Taken together, these results favor the notion of a transporter-mediated tight control of the uptake process.

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Glutamate activation of Oct-2 in cultured chick Bergmann glia cells: Involvement of NFκB

Cited by 4 publications

References 64 publications

Glutamate‐induced octamer DNA binding and transcriptional control in cultured radial glia cells

Glutamate‐induced octamer DNA binding and transcriptional control in cultured radial glia cells

AMPA receptors modulate the reorganization of F‐actin in Bergmann glia cells through the activation of RhoA

An Acute Glutamate Exposure Induces Long-Term Down Regulation of GLAST/EAAT1 Uptake Activity in Cultured Bergmann Glia Cells

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