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Title: Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid

Abstract

Highlights: {yields} NGFI-B and RXR translocate out of the nucleus after glutamate treatment. {yields} Arresting NGFI-B/RXR in the nucleus protects neurons from excitotoxicity. {yields} Late protection by 9-cis RA is possible due to a delayed translocation of NGFI-B/RXR. -- Abstract: Nuclear receptor and apoptosis inducer NGFI-B translocates out of the nucleus as a heterodimer with RXR in response to different apoptosis stimuli, and therefore represents a potential pharmacological target. We found that the cytosolic levels of NGFI-B and RXR{alpha} were increased in cultures of cerebellar granule neurons 2 h after treatment with glutamate (excitatory neurotransmitter in the brain, involved in stroke). To find a time-window for potential intervention the neurons were transfected with gfp-tagged expressor plasmids for NGFI-B and RXR. The default localization of NGFI-Bgfp and RXRgfp was nuclear, however, translocation out of the nucleus was observed 2-3 h after glutamate treatment. We therefore hypothesized that the time-window between treatment and translocation would allow late protection against neuronal death. The RXR ligand 9-cis retinoic acid was used to arrest NGFI-B and RXR in the nucleus. Addition of 9-cis retinoic acid 1 h after treatment with glutamate reduced the cytosolic translocation of NGFI-B and RXR{alpha}, the cytosolic translocation of NGFI-Bgfp observedmore » in live neurons, as well as the neuronal death. However, the reduced translocation and the reduced cell death were not observed when 9-cis retinoic acid was added after 3 h. Thus, late protection from glutamate induced death by addition of 9-cis retinoic acid is possible in a time-window after apoptosis induction.« less

Authors:
; ; ; ;  [1];  [1]
  1. Department of Pharmaceutical Biosciences, University of Oslo, P.O. Box 1068, Blindern, N-0316 Oslo (Norway)
Publication Date:
OSTI Identifier:
22207518
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 414; Journal Issue: 1; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; APOPTOSIS; BRAIN; DEATH; FLUORESCENCE; GROWTH FACTORS; LIGANDS; NERVE CELLS; PLASMIDS; RECEPTORS; RETINOIC ACID; TRANSLOCATION

Citation Formats

Mathisen, Gro H., Fallgren, Asa B., Strom, Bjorn O., Boldingh Debernard, Karen A., Mohebi, Beata U., and Paulsen, Ragnhild E., E-mail: r.e.paulsen@farmasi.uio.no. Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid. United States: N. p., 2011. Web. doi:10.1016/J.BBRC.2011.09.028.
Mathisen, Gro H., Fallgren, Asa B., Strom, Bjorn O., Boldingh Debernard, Karen A., Mohebi, Beata U., & Paulsen, Ragnhild E., E-mail: r.e.paulsen@farmasi.uio.no. Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid. United States. doi:10.1016/J.BBRC.2011.09.028.
Mathisen, Gro H., Fallgren, Asa B., Strom, Bjorn O., Boldingh Debernard, Karen A., Mohebi, Beata U., and Paulsen, Ragnhild E., E-mail: r.e.paulsen@farmasi.uio.no. Fri . "Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid". United States. doi:10.1016/J.BBRC.2011.09.028.
@article{osti_22207518,
title = {Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid},
author = {Mathisen, Gro H. and Fallgren, Asa B. and Strom, Bjorn O. and Boldingh Debernard, Karen A. and Mohebi, Beata U. and Paulsen, Ragnhild E., E-mail: r.e.paulsen@farmasi.uio.no},
abstractNote = {Highlights: {yields} NGFI-B and RXR translocate out of the nucleus after glutamate treatment. {yields} Arresting NGFI-B/RXR in the nucleus protects neurons from excitotoxicity. {yields} Late protection by 9-cis RA is possible due to a delayed translocation of NGFI-B/RXR. -- Abstract: Nuclear receptor and apoptosis inducer NGFI-B translocates out of the nucleus as a heterodimer with RXR in response to different apoptosis stimuli, and therefore represents a potential pharmacological target. We found that the cytosolic levels of NGFI-B and RXR{alpha} were increased in cultures of cerebellar granule neurons 2 h after treatment with glutamate (excitatory neurotransmitter in the brain, involved in stroke). To find a time-window for potential intervention the neurons were transfected with gfp-tagged expressor plasmids for NGFI-B and RXR. The default localization of NGFI-Bgfp and RXRgfp was nuclear, however, translocation out of the nucleus was observed 2-3 h after glutamate treatment. We therefore hypothesized that the time-window between treatment and translocation would allow late protection against neuronal death. The RXR ligand 9-cis retinoic acid was used to arrest NGFI-B and RXR in the nucleus. Addition of 9-cis retinoic acid 1 h after treatment with glutamate reduced the cytosolic translocation of NGFI-B and RXR{alpha}, the cytosolic translocation of NGFI-Bgfp observed in live neurons, as well as the neuronal death. However, the reduced translocation and the reduced cell death were not observed when 9-cis retinoic acid was added after 3 h. Thus, late protection from glutamate induced death by addition of 9-cis retinoic acid is possible in a time-window after apoptosis induction.},
doi = {10.1016/J.BBRC.2011.09.028},
journal = {Biochemical and Biophysical Research Communications},
number = 1,
volume = 414,
place = {United States},
year = {Fri Oct 14 00:00:00 EDT 2011},
month = {Fri Oct 14 00:00:00 EDT 2011}
}
  • Human inducible nitric oxide synthase (hiNOS) catalyzes nitric oxide (NO) which has a significant effect on tumor suppression and cancer therapy. Here we revealed the detailed molecular mechanism involved in the regulation of hiNOS expression induced by retinoic acid (RA). We showed that RAR{alpha}/RXR{alpha} heterodimer was important in hiNOS promoter activation, hiNOS protein expression, and NO production. Serial deletion and site-directed mutation analysis revealed two half-sites of retinoic acid response element (RARE) spaced by 5 bp located at -172 to -156 in the hiNOS promoter. EMSA and ChIP assays demonstrated that RAR{alpha}/RXR{alpha} directly bound to this RARE of hiNOS promoter.more » Our results suggested the identification of a novel RARE in the hiNOS promoter and the roles of the nuclear receptors (RAR{alpha}/RXR{alpha}) in the induction of hiNOS by RA.« less
  • Although a crystal structure and a pharmacophore model are available for cytochrome P450 2C8, the role of protein flexibility and specific ligand-protein interactions that govern substrate binding are poorly understood. X-ray crystal structures of P450 2C8 complexed with montelukast (2.8 {angstrom}), troglitazone (2.7 {angstrom}), felodipine (2.3 {angstrom}), and 9-cis-retinoic acid (2.6 {angstrom}) were determined to examine ligand-protein interactions for these chemically diverse compounds. Montelukast is a relatively large anionic inhibitor that exhibits a tripartite structure and complements the size and shape of the active-site cavity. The inhibitor troglitazone occupies the upper portion of the active-site cavity, leaving a substantial partmore » of the cavity unoccupied. The smaller neutral felodipine molecule is sequestered with its dichlorophenyl group positioned close to the heme iron, and water molecules fill the distal portion of the cavity. The structure of the 9-cis-retinoic acid complex reveals that two substrate molecules bind simultaneously in the active site of P450 2C8. A second molecule of 9-cis-retinoic acid is located above the proximal molecule and can restrain the position of the latter for more efficient oxygenation. Solution binding studies do not discriminate between cooperative and noncooperative models for multiple substrate binding. The complexes with structurally distinct ligands further demonstrate the conformational adaptability of active site-constituting residues, especially Arg-241, that can reorient in the active-site cavity to stabilize a negatively charged functional group and define two spatially distinct binding sites for anionic moieties of substrates.« less
  • Highlights: ► We examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1. ► 9-cis-RA inhibited lipid accumulation in adipogenetically-induced 3T3-L1 cells. ► A RXR pan-antagonist suppressed the inhibitory effects of 9-cis-RA on adipogenesis. ► This antagonist had no effects on RXRα and PPARγ levels in 9-cis-RA-treated cells. ► 9-cis-RA-induced decrease in both RXRα and PPARγ was independent of RXR activation. -- Abstract: Retinoic acid (RA) signaling is mediated by specific nuclear hormone receptors. Here we examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1 cells. 9-cis-RA inhibits the lipid accumulation of adipogenetically induced 3T3-L1 cells. Themore » complex of retinoid X receptor α (RXRα) with peroxisome proliferator-activated receptor γ (PPARγ) is a major transcription factor in the process of adipogenesis, and the levels of these molecules were decreased by 9-cis-RA treatment. A RXR pan-antagonist suppressed 9-cis-RA’s inhibitory effects on adipogenesis, but not on the intracellular levels of both RXRα and PPARγ. These results suggest that 9-cis-RA could inhibit adipogenesis by activating RXR, and decrease both RXR and PPARγs levels in a RXR activation-independent manner.« less
  • No abstract prepared.
  • In primary cultures of cerebellar granule cells, protein kinase C (PKC) translocation and activation can be triggered by the stimulation of excitatory amino acid neurotransmitter receptors. Glutamate evokes a dose-related translocation of 4-..beta..-(/sup 3/H)phorbol 12,13-dibutyrate /(/sup 3/H)-P(BtO)/sub 2// binding sites from the cytosol to the neuronal membrane and stimulates the incorporation of /sup 32/P into a number of membrane proteins, particularly protein bands in the range of 80, 50, and 40 kDa. The glutamate-evoked PKC translocation is Mg/sup 2 +/ sensitive, is prevented by 2-amino-5-phosphonovalerate and phencyclidine, is not inhibited by nitrendipine (a voltage-dependent Ca/sup 2 +/-channel-blocker) but is abolishedmore » by the removal of Ca/sup 2 +/ from the incubation medium, suggesting that glutamate-mediated Ca/sup 2 +/ influx is operative in the redistribution of PKC. Exposure of granule cells to the gangliosides trisialosylgangliotetraglycosylceramide (GT1b) of monosialosylgangliotetraglycosylceramide (GM1) inhibits the translocation and activation of PKC evoked by glutamate. These glycosphingolipids fail to interfere with glutamate binding to its high-affinity recognition site of with the (/sup 3/H)P(BtO)/sub 2/ binding, nor do they affect the Ca/sup 2 +/ influx. These gangliosides may prevent PKC translocation by interfering with the PKC binding to the neuronal membrane phosphatidylserine.« less