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Jiang SZ, Shahoha M, Zhang HY, Brancaleone W, Elkahloun A, Tejeda HA, Ashery U, Eiden LE. The guanine nucleotide exchange factor RapGEF2 is required for ERK-dependent immediate-early gene (Egr1) activation during fear memory formation. Cell Mol Life Sci 2024; 81:48. [PMID: 38236296 PMCID: PMC11071968 DOI: 10.1007/s00018-023-04999-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 09/16/2023] [Accepted: 10/04/2023] [Indexed: 01/19/2024]
Abstract
The MAP kinase ERK is important for neuronal plasticity underlying associative learning, yet specific molecular pathways for neuronal ERK activation are undetermined. RapGEF2 is a neuron-specific cAMP sensor that mediates ERK activation. We investigated whether it is required for cAMP-dependent ERK activation leading to other downstream neuronal signaling events occurring during associative learning, and if RapGEF2-dependent signaling impairments affect learned behavior. Camk2α-cre+/-::RapGEF2fl/fl mice with depletion of RapGEF2 in hippocampus and amygdala exhibit impairments in context- and cue-dependent fear conditioning linked to corresponding impairment in Egr1 induction in these two brain regions. Camk2α-cre+/-::RapGEF2fl/fl mice show decreased RapGEF2 expression in CA1 and dentate gyrus associated with abolition of pERK and Egr1, but not of c-Fos induction, following fear conditioning, impaired freezing to context after fear conditioning, and impaired cAMP-dependent long-term potentiation at perforant pathway and Schaffer collateral synapses in hippocampal slices ex vivo. RapGEF2 expression is largely eliminated in basolateral amygdala, also involved in fear memory, in Camk2α-cre+/-::RapGEF2fl/fl mice. Neither Egr1 nor c-fos induction in BLA after fear conditioning, nor cue-dependent fear learning, are affected by ablation of RapGEF2 in BLA. However, Egr1 induction (but not that of c-fos) in BLA is reduced after restraint stress-augmented fear conditioning, as is freezing to cue after restraint stress-augmented fear conditioning, in Camk2α-cre+/-::RapGEF2fl/fl mice. Cyclic AMP-dependent GEFs have been genetically associated as risk factors for schizophrenia, a disorder associated with cognitive deficits. Here we show a functional link between one of them, RapGEF2, and cognitive processes involved in associative learning in amygdala and hippocampus.
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Affiliation(s)
- Sunny Zhihong Jiang
- Section On Molecular Neuroscience, NIMH Intramural Research Program, 9000 Rockville Pike, Building 49, Room 5A38, Bethesda, MD, 20892, USA
| | - Meishar Shahoha
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, and Sagol School of Neuroscience, Tel Aviv University, Sherman Building Rm 719, Ramat Aviv, 69978, Tel Aviv, Israel
| | - Hai-Ying Zhang
- Section On Molecular Neuroscience, NIMH Intramural Research Program, 9000 Rockville Pike, Building 49, Room 5A38, Bethesda, MD, 20892, USA
| | - William Brancaleone
- Section On Molecular Neuroscience, NIMH Intramural Research Program, 9000 Rockville Pike, Building 49, Room 5A38, Bethesda, MD, 20892, USA
| | | | - Hugo A Tejeda
- Unit on Neuromodulation and Synaptic Integration, NIMH-IRP, Bethesda, MD, USA
| | - Uri Ashery
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, and Sagol School of Neuroscience, Tel Aviv University, Sherman Building Rm 719, Ramat Aviv, 69978, Tel Aviv, Israel.
| | - Lee E Eiden
- Section On Molecular Neuroscience, NIMH Intramural Research Program, 9000 Rockville Pike, Building 49, Room 5A38, Bethesda, MD, 20892, USA.
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Xu W, Dahlke SP, Sung M, Samal B, Emery AC, Elkahloun A, Eiden LE. ERK-dependent induction of the immediate-early gene Egr1 and the late gene Gpr50 contribute to two distinct phases of PACAP Gs-GPCR signaling for neuritogenesis. J Neuroendocrinol 2022; 34:e13182. [PMID: 35841324 PMCID: PMC9529758 DOI: 10.1111/jne.13182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/28/2022]
Abstract
Gs-coupled GPCR-stimulated neuritogenesis in PC12 and NS-1 - cells depends on activation of the MAP kinase ERK. Here, we examine changes in ERK activation (phosphorylation), and the time course of ERK-dependent gene induction, to seek transcriptional determinants for this process. Quenching of ERK activation by inhibition of MEK with U0126 at any time point for at least 24 h following addition of PACAP resulted in arrest of neurite formation. Changes in the transcriptome profile throughout this time period revealed at least two phases of gene induction: an early phase dominated by induction of immediate-early genes, and a later phase of gene induction after 4-6 h of exposure to PACAP with persistent elevation of phospho-ERK levels. Genes induced by PACAP in both phases consisted in those whose induction was dependent on ERK (i.e., blocked by U0126), and some whose induction was blocked by the protein kinase A inhibitor H89. ERK-dependent "late gene" transcripts included Gpr50, implicated earlier in facilitation of NGF-induced neurite formation in NS-1 cells. Gpr50 induction by PACAP, but not NGF, was dependent on the guanine nucleotide exchange factor RapGEF2, which has been shown to be required for PACAP-induced neuritogenesis in NS-1 cells. Expression of a Gpr50-directed shRNA lowered basal levels of Gpr50 mRNA and attenuated Gpr50 mRNA and GPR50 protein induction by PACAP, with a corresponding attenuation of PACAP-induced neuritogenesis. Gs-GPCR-stimulated neuritogenesis first requires immediate-early gene induction, including that of Egr1 (Zif268/NGF1A/Krox24) as previously reported. This early phase of gene induction, however, is insufficient to maintain the neuritogenic process without ERK-dependent induction of additional late genes, including Gpr50, upon continuous exposure to neurotrophic neuropeptide. Early (Egr1) and late (Gpr50) gene induction by NGF, like that for PACAP, was inhibited by U0126, but was independent of RapGEF2, confirming distinct modes of ERK activation by Gs-coupled GPCRs and neurotrophic tyrosine receptor kinases, converging on a final common ERK-dependent signaling pathway for neuritogenesis.
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Affiliation(s)
- Wenqin Xu
- Section on Molecular Neuroscience, National Institute of Mental Health-Intramural Research Program
| | - Sam P. Dahlke
- Section on Molecular Neuroscience, National Institute of Mental Health-Intramural Research Program
| | - Michelle Sung
- Section on Molecular Neuroscience, National Institute of Mental Health-Intramural Research Program
| | - Babru Samal
- Section on Molecular Neuroscience, National Institute of Mental Health-Intramural Research Program
| | - Andrew C. Emery
- Section on Molecular Neuroscience, National Institute of Mental Health-Intramural Research Program
| | - Abdel Elkahloun
- Microarray Core, National Human Genome Research Institute, Bethesda, MD, USA
| | - Lee E. Eiden
- Section on Molecular Neuroscience, National Institute of Mental Health-Intramural Research Program
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Shahoha M, Cohen R, Ben-Simon Y, Ashery U. cAMP-Dependent Synaptic Plasticity at the Hippocampal Mossy Fiber Terminal. Front Synaptic Neurosci 2022; 14:861215. [PMID: 35444523 PMCID: PMC9013808 DOI: 10.3389/fnsyn.2022.861215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/23/2022] [Indexed: 11/24/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a crucial second messenger involved in both pre- and postsynaptic plasticity in many neuronal types across species. In the hippocampal mossy fiber (MF) synapse, cAMP mediates presynaptic long-term potentiation and depression. The main cAMP-dependent signaling pathway linked to MF synaptic plasticity acts via the activation of the protein kinase A (PKA) molecular cascade. Accordingly, various downstream putative synaptic PKA target proteins have been linked to cAMP-dependent MF synaptic plasticity, such as synapsin, rabphilin, synaptotagmin-12, RIM1a, tomosyn, and P/Q-type calcium channels. Regulating the expression of some of these proteins alters synaptic release probability and calcium channel clustering, resulting in short- and long-term changes to synaptic efficacy. However, despite decades of research, the exact molecular mechanisms by which cAMP and PKA exert their influences in MF terminals remain largely unknown. Here, we review current knowledge of different cAMP catalysts and potential downstream PKA-dependent molecular cascades, in addition to non-canonical cAMP-dependent but PKA-independent cascades, which might serve as alternative, compensatory or competing pathways to the canonical PKA cascade. Since several other central synapses share a similar form of presynaptic plasticity with the MF, a better description of the molecular mechanisms governing MF plasticity could be key to understanding the relationship between the transcriptional and computational levels across brain regions.
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Affiliation(s)
- Meishar Shahoha
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ronni Cohen
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Ben-Simon
- Department of Neurophysiology, Vienna Medical University, Vienna, Austria
- *Correspondence: Yoav Ben-Simon,
| | - Uri Ashery
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Uri Ashery,
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Nishimoto-Kusunose S, Sawa M, Inaba Y, Ushiyama A, Ishii K, Hattori K, Ogasawara Y. Exposure to aerosol extract from heated tobacco products causes a drastic decrease of glutathione and protein carbonylation in human lung epithelial cells. Biochem Biophys Res Commun 2022; 589:92-99. [PMID: 34896781 DOI: 10.1016/j.bbrc.2021.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/02/2021] [Indexed: 12/20/2022]
Abstract
Heated tobacco products (HTPs) are an emerging class of tobacco goods that claim to have lower health risks than those of smoking combustible tobacco products. In this study, we exposed human lung epithelial cell lines to extracts prepared from HTP aerosols and combustible cigarette smoke to compare cytotoxicity. We focused on the effects of aldehydes present in the aerosols of HTPs at levels close to those in combustible cigarette smoke. Significant toxicity was confirmed for the HTP extract, albeit to a lesser extent than that with the combustible cigarette extract. When redox balance was evaluated by the oxidative loss of low-molecular-weight thiols in the cells, we found that total glutathione (GSH) contents and low-molecular-weight thiol levels were significantly decreased after exposure to the aerosol extract of HTPs. These results indicated that GSH is rapidly consumed during the detoxification of xenobiotics, such as aldehydes from tobacco extracts. Accordingly, exposure to the aerosol extract of HTPs resulted in the enhanced carbonylation of many proteins. In a simple comparison, the results for HTPs were significantly different from those obtained with combustible cigarette smoke, suggesting reduced toxicity of HTPs. However, we found significant and harmful effects after exposing lung epithelial cells to the aerosol extract of HTPs. Thus, a further comprehensive study is needed to clarify the lung damage induced via the long-term inhalation of aerosols from HTPs.
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Affiliation(s)
- S Nishimoto-Kusunose
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan
| | - M Sawa
- Department of Environmental Science, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Y Inaba
- Department of Environmental Health, National Institute of Public Health. Minami, Wako-shi, Saitama, 351-0197, Japan
| | - A Ushiyama
- Department of Environmental Health, National Institute of Public Health. Minami, Wako-shi, Saitama, 351-0197, Japan
| | - K Ishii
- Department of Environmental Science, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - K Hattori
- Department of Environmental Science, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Y Ogasawara
- Department of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan.
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Mendieta I, Rodríguez-Nieto M, Nuñez-Anita RE, Menchaca-Arredondo JL, García-Alcocer G, Berumen LC. Ultrastructural changes associated to the neuroendocrine transdifferentiation of the lung adenocarcinoma cell line A549. Acta Histochem 2021; 123:151797. [PMID: 34688180 DOI: 10.1016/j.acthis.2021.151797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 09/29/2021] [Accepted: 10/05/2021] [Indexed: 12/13/2022]
Abstract
The neuroendocrine transdifferentiation has been found in many cancer cell types, such as prostate, lung and gastrointestinal cells and is accompanied by a lower patient life expectancy. The transdifferentiation process has been induced in vitro by the exposure to different stimuli in human lung adenocarcinoma. The aim of this work was to identify the morphological characteristics of the neuroendocrine phenotype in a human lung cancer cell line, induced by two cAMP elevating agents (IBMX and FSK). Our results showed two phenotypes, one produced by IBMX with higher volume, cell size and increased number of secondary projections, and the other produced by FSK with higher area, roughness of the membrane, cell neurite percentage, number of outgrowths per cell and increased number of primary projections. In conclusion, we describe some morphological and ultrastructural characteristics of the neuroendocrine phenotype in A549 human lung cancer cell line promoted by IBMX and FSK to contribute to the understanding of the autocrine or paracrine signaling within the tumor microenvironment.
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Affiliation(s)
- Irasema Mendieta
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario S/N, Cerro de las Campanas 76010, Querétaro, Mexico
| | - Maricela Rodríguez-Nieto
- Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia 58060, Michoacán, Mexico
| | - Rosa Elvira Nuñez-Anita
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás Hidalgo, Tarímbaro Municipio de Morelia 58920, Michoacán, Mexico
| | - Jorge Luis Menchaca-Arredondo
- Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, Centro de Investigación en Ciencias Físico Matemáticas, San Nicolás de los Garza 66455, Nuevo León, Mexico
| | - Guadalupe García-Alcocer
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario S/N, Cerro de las Campanas 76010, Querétaro, Mexico
| | - Laura Cristina Berumen
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario S/N, Cerro de las Campanas 76010, Querétaro, Mexico.
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Xu W, Dahlke SP, Emery AC, Sung M, Chepurny OG, Holz GG, Eiden LE. Cyclic AMP-dependent activation of ERK via GLP-1 receptor signalling requires the neuroendocrine cell-specific guanine nucleotide exchanger NCS-RapGEF2. J Neuroendocrinol 2021; 33:e12974. [PMID: 33960038 PMCID: PMC8571116 DOI: 10.1111/jne.12974] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 01/27/2023]
Abstract
Cyclic AMP activation of the Rap-Braf-MEK-ERK pathway after signalling initiated by the neuropeptide pituitary adenylate cyclase-activating peptide (PACAP), via the Gs -protein coupled receptor (Gs PCR) PAC1, occurs uniquely through the neuritogenic cAMP sensor Rap guanine nucleotide exchange factor 2 (NCS-RapGEF2) in Neuroscreen-1 (NS-1) neuroendocrine cells. We examined the expression of other Family B Gs PCRs in this cell line and assessed cAMP elevation and neuritogenesis after treatment with their cognate peptide ligands. Exposure of NS-1 cells to the VIPR1/2 agonist vasoactive intestinal polypeptide, or the GLP1R agonist exendin-4, did not induce neuritogenesis, or elevation of cAMP, presumably as a result of insufficient receptor protein expression. Vasoactive intestinal polypeptide and exendin-4 did induce neuritogenesis after transduction of human VIPR1, VIPR2 and GLP1R into NS-1 cells. Exendin-4/GLP1R-stimulated neuritogenesis was MEK-ERK-dependent (blocked by U0126), indicating its use of the cAMP→RapGEF2→ERK neuritogenic signalling pathway previously identified for PACAP/PAC1 signalling in NS-1 cells. NCS-RapGEF2 is expressed in the rodent insulinoma cell lines MIN6 and INS-1, as well as in human pancreatic islets. As in NS-1 cells, exendin-4 caused ERK phosphorylation in INS-1 cells. Reduction in RapGEF2 expression after RapGEF2-shRNA treatment reduced exendin-4-induced ERK phosphorylation. Transcriptome analysis of INS-1 cells after 1 hour of exposure to exendin-4 revealed an immediate early-gene response that was composed of both ERK-dependent and ERK-independent signalling targets. We propose that cAMP signalling initiated by glucagon-like peptide 1 (GLP-1) in pancreatic beta cells causes parallel activation of multiple cAMP effectors, including NCS-RapGEF2, Epac and protein kinase A, to separately control various facets of GLP-1 action, including insulin secretion and transcriptional modulation.
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Affiliation(s)
- Wenqin Xu
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Sam P. Dahlke
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Andrew C. Emery
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Michelle Sung
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
| | - Oleg G. Chepurny
- Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA
| | - George G. Holz
- Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA
| | - Lee E. Eiden
- Section on Molecular Neuroscience, National Institute of Mental Health – Intramural Research Program, Bethesda, MD, USA
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Cocaine-Dependent Acquisition of Locomotor Sensitization and Conditioned Place Preference Requires D1 Dopaminergic Signaling through a Cyclic AMP, NCS-Rapgef2, ERK, and Egr-1/Zif268 Pathway. J Neurosci 2020; 41:711-725. [PMID: 33268547 DOI: 10.1523/jneurosci.1497-20.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/08/2020] [Accepted: 11/15/2020] [Indexed: 11/21/2022] Open
Abstract
Elucidation of the mechanism of dopamine signaling to ERK that underlies plasticity in dopamine D1 receptor-expressing neurons leading to acquired cocaine preference is incomplete. NCS-Rapgef2 is a novel cAMP effector, expressed in neuronal and endocrine cells in adult mammals, that is required for D1 dopamine receptor-dependent ERK phosphorylation in mouse brain. In this report, we studied the effects of abrogating NCS-Rapgef2 expression on cAMP-dependent ERK→Egr-1/Zif268 signaling in cultured neuroendocrine cells; in D1 medium spiny neurons of NAc slices; and in either male or female mouse brain in a region-specific manner. NCS-Rapgef2 gene deletion in the NAc in adult mice, using adeno-associated virus-mediated expression of cre recombinase, eliminated cocaine-induced ERK phosphorylation and Egr-1/Zif268 upregulation in D1-medium spiny neurons and cocaine-induced behaviors, including locomotor sensitization and conditioned place preference. Abrogation of NCS-Rapgef2 gene expression in mPFC and BLA, by crossing mice bearing a floxed Rapgef2 allele with a cre mouse line driven by calcium/calmodulin-dependent kinase IIα promoter also eliminated cocaine-induced phospho-ERK activation and Egr-1/Zif268 induction, but without effect on the cocaine-induced behaviors. Our results indicate that NCS-Rapgef2 signaling to ERK in dopamine D1 receptor-expressing neurons in the NAc, but not in corticolimbic areas, contributes to cocaine-induced locomotor sensitization and conditioned place preference. Ablation of cocaine-dependent ERK activation by elimination of NCS-Rapgef2 occurred with no effect on phosphorylation of CREB in D1 dopaminoceptive neurons of NAc. This study reveals a new cAMP-dependent signaling pathway for cocaine-induced behavioral adaptations, mediated through NCS-Rapgef2/phospho-ERK activation, independently of PKA/CREB signaling.SIGNIFICANCE STATEMENT ERK phosphorylation in dopamine D1 receptor-expressing neurons exerts a pivotal role in psychostimulant-induced neuronal gene regulation and behavioral adaptation, including locomotor sensitization and drug preference in rodents. In this study, we examined the role of dopamine signaling through the D1 receptor via a novel pathway initiated through the cAMP-activated guanine nucleotide exchange factor NCS-Rapgef2 in mice. NCS-Rapgef2 in the NAc is required for activation of ERK and Egr-1/Zif268 in D1 dopaminoceptive neurons after acute cocaine administration, and subsequent enhanced locomotor response and drug seeking behavior after repeated cocaine administration. This novel component in dopamine signaling provides a potential new target for intervention in psychostimulant-shaped behaviors, and new understanding of how D1-medium spiny neurons encode the experience of psychomotor stimulant exposure.
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Wang P, Luchowska-Stańska U, van Basten B, Chen H, Liu Z, Wiejak J, Whelan P, Morgan D, Lochhead E, Barker G, Rehmann H, Yarwood SJ, Zhou J. Synthesis and Biochemical Evaluation of Noncyclic Nucleotide Exchange Proteins Directly Activated by cAMP 1 (EPAC1) Regulators. J Med Chem 2020; 63:5159-5184. [PMID: 32340447 DOI: 10.1021/acs.jmedchem.9b02094] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Exchange proteins directly activated by cAMP (EPAC) play a central role in various biological functions, and activation of the EPAC1 protein has shown potential benefits for the treatment of various human diseases. Herein, we report the synthesis and biochemical evaluation of a series of noncyclic nucleotide EPAC1 activators. Several potent EPAC1 binders were identified including 25g, 25q, 25n, 25u, 25e, and 25f, which promote EPAC1 guanine nucleotide exchange factor activity in vitro. These agonists can also activate EPAC1 protein in cells, where they exhibit excellent selectivity toward EPAC over protein kinase A and G protein-coupled receptors. Moreover, 25e, 25f, 25n, and 25u exhibited improved selectivity toward activation of EPAC1 over EPAC2 in cells. Of these, 25u was found to robustly inhibit IL-6-activated signal transducer and activator of transcription 3 (STAT3) and subsequent induction of the pro-inflammatory vascular cell adhesion molecule 1 (VCAM1) cell-adhesion protein. These novel EPAC1 activators may therefore act as useful pharmacological tools for elucidation of EPAC function and promising drug leads for the treatment of relevant human diseases.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Boy van Basten
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jolanta Wiejak
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Padraic Whelan
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Emma Lochhead
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Holger Rehmann
- Department of Molecular Cancer Research, Centre of Biomedical Genetics and Cancer Genomics Centre, University Medical Centre Utrecht, Utrecht 3584 CX, Netherlands
| | - Stephen J Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, U.K
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
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Richard SA. EPAC2: A new and promising protein for glioma pathogenesis and therapy. Oncol Rev 2020; 14:446. [PMID: 32395202 PMCID: PMC7204831 DOI: 10.4081/oncol.2020.446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 04/16/2020] [Indexed: 01/02/2023] Open
Abstract
Gliomas are prime brain cancers which are initiated by malignant modification of neural stem cells, progenitor cells and differentiated glial cells such as astrocyte, oligodendrocyte as well as ependymal cells. Exchange proteins directly activated by cAMP (EPACs) are crucial cyclic adenosine 3’,5’-monophosphate (cAMP)-determined signaling pathways. Cyclic AMP-intermediated signaling events were utilized to transduce protein kinase A (PKA) leading to the detection of EPACs or cAMP-guanine exchange factors (cAMP-GEFs). EPACs have been detected as crucial proteins associated with the pathogenesis of neurological disorders as well as numerous human diseases. EPAC proteins have two isoforms. These isoforms are EPAC1 and EPAC2. EPAC2 also known as Rap guanine nucleotide exchange factor 4 (RAPGEF4) is generally expression in all neurites. Higher EAPC2 levels was detected in the cortex, hippocampus as well as striatum of adult mouse brain. Activation as well as over-secretion of EPAC2 triggers apoptosis in neurons and EPAC-triggered apoptosis was intermediated via the modulation of Bcl-2 interacting member protein (BIM). EPAC2 secretory levels has proven to be more in low-grade clinical glioma than high-grade clinical glioma. This review therefore explores the effects of EPAC2/RAPGEF4 on the pathogenesis of glioma instead of EPAC1 because EPAC2 and not EPAC1 is predominately expressed in the brain. Therefore, EPAC2 is most likely to modulate glioma pathogenesis rather than EPAC1.
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Affiliation(s)
- Seidu A Richard
- Department of Medicine, Princefield University, Ho, Ghana, West Africa
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Ramos-Alvarez I, Lee L, Jensen RT. Cyclic AMP-dependent protein kinase A and EPAC mediate VIP and secretin stimulation of PAK4 and activation of Na +,K +-ATPase in pancreatic acinar cells. Am J Physiol Gastrointest Liver Physiol 2019; 316:G263-G277. [PMID: 30520694 PMCID: PMC6397337 DOI: 10.1152/ajpgi.00275.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rat pancreatic acinar cells possess only the p21-activated kinase (PAKs), PAK4 of the group II PAK, and it is activated by gastrointestinal hormones/neurotransmitters stimulating PLC and by a number of growth factors. However, little is known generally of cAMP agents causing PAK4 activation, and there are no studies with gastrointestinal hormones/neurotransmitters activating cAMP cascades. In the present study, we examined the ability of VIP and secretin, which stimulate cAMP generation in pancreatic acini, to stimulate PAK4 activation, the signaling cascades involved, and their possible role in activating sodium-potassium adenosine triphosphatase (Na+,K+-ATPase). PAK4 activation was compared with activation of the well-established cAMP target, cyclic AMP response element binding protein (CREB). Secretin-stimulated PAK4 activation was inhibited by KT-5720 and PKA Type II inhibitor (PKI), protein kinase A (PKA) inhibitors, whereas VIP activation was inhibited by ESI-09 and HJC0197, exchange protein directly activated by cAMP (EPAC) inhibitors. In contrast, both VIP/secretin-stimulated phosphorylation of CREB (pCREB) via EPAC activation; however, it was inhibited by the p44/42 inhibitor PD98059 and the p38 inhibitor SB202190. The specific EPAC agonist 8-CPT-2- O-Me-cAMP as well 8-Br-cAMP and forskolin stimulated PAK4 activation. Secretin/VIP activation of Na+,K+-ATPase, was inhibited by PAK4 inhibitors (PF-3758309, LCH-7749944). These results demonstrate PAK4 is activated in pancreatic acini by stimulation of both VIP-/secretin-preferring receptors, as is CREB. However, they differ in their signaling cascades. Furthermore, PAK4 activation is needed for Na+,K+ATPase activation, which mediates pancreatic fluid secretion. These results, coupled with recent studies reporting PAKs are involved in both pancreatitis/pancreatic cancer growth/enzyme secretion, show that PAK4, similar to PAK2, likely plays an important role in both pancreatic physiological/pathological responses. NEW & NOTEWORTHY Pancreatic acini possess only the group II p21-activated kinase, PAK4, which is activated by PLC-stimulating agents/growth factors and is important in enzyme-secretion/growth/pancreatitis. Little information exists on cAMP-activating agents stimulating group II PAKs. We studied ability/effect of cyclic AMP-stimulating agents [vasoactive intestinal polypeptide (VIP), secretin] on PAK4 activity in rat pancreatic-acini. Both VIP/secretin activated PAK4/CREB, but the cAMP signaling cascades differed for EPAC, MAPK, and PKA pathways. Both hormones require PAK4 activation to stimulate sodium-potassium adenosine triphosphatase activity. This study shows PAK4 plays an important role in VIP-/secretin-stimulated pancreatic fluid secretion and suggests it plays important roles in pancreatic acinar physiological/pathophysiological responses mediated by cAMP-activating agents.
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Affiliation(s)
- Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - R. T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Zhuang Y, Xu H, Richard SA, Cao J, Li H, Shen H, Yu Z, Zhang J, Wang Z, Li X, Chen G. Inhibition of EPAC2 Attenuates Intracerebral Hemorrhage-Induced Secondary Brain Injury via the p38/BIM/Caspase-3 Pathway. J Mol Neurosci 2019; 67:353-363. [PMID: 30607901 DOI: 10.1007/s12031-018-1215-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 11/11/2018] [Indexed: 12/14/2022]
Abstract
Exchange proteins directly activated by cAMP (EPACs) are critical cAMP-dependent signaling pathway intermediaries that have been implicated in the pathogenesis of several human diseases, particularly neurological disorders. However, their pathogenic role in secondary brain injury (SBI) induced by intracranial hemorrhage (ICH) is unknown. The aim of this study was to examine the effects of EPAC2 on ICH-induced SBI and its underlying mechanisms. An in vivo ICH model was established in Sprague-Dawley rats by autologous blood injection. In addition, rat primary cortical neuronal cultures were exposed to oxyhemoglobin to simulate ICH in vitro. The function of EPAC2 in SBI induced by ICH was studied using the EPAC2-specific inhibitor ESI-05. In this study, we found that EPAC2 protein expression was significantly increased in the ICH models in vitro and in vivo. Furthermore, EPAC2 activation was inhibited by ESI-05 under ICH conditions. Inhibition of EPAC2 decreased the apoptosis rate of nerve cells in the cortex accompanied by a corresponding decrease in the protein expression of phosphorylated p38, Bcl-2-like protein 11 (BIM), and caspase-3. In summary, this study showed that inhibition of EPAC2 activation by ESI-05 suppressed SBI induced by ICH via the p38/BIM/caspase-3 signaling pathway.
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Affiliation(s)
- Yan Zhuang
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China.,Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, 438 Jiefang Road, Zhenjiang, 212001, Jiangsu Province, China
| | - Hui Xu
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China.,Department of Neurosurgery, The Sixth People's Hospital of Nantong, No. 500 Yonghe Road, Nantong, 226011, Jiangsu Province, China
| | - Seidu A Richard
- Department of Immunology, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, Jiangsu Province, China
| | - Jie Cao
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China
| | - Haiying Li
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China
| | - Haitao Shen
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China
| | - Zhengquan Yu
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China
| | - Jian Zhang
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China
| | - Zhong Wang
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China.
| | - Xiang Li
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China.
| | - Gang Chen
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, Jiangsu Province, China
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12
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Two ancient neuropeptides, PACAP and AVP, modulate motivated behavior at synapses in the extrahypothalamic brain: a study in contrast. Cell Tissue Res 2018; 375:103-122. [DOI: 10.1007/s00441-018-2958-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 11/05/2018] [Indexed: 01/24/2023]
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13
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Mayati A, Moreau A, Le Vée M, Bruyère A, Jouan E, Denizot C, Parmentier Y, Fardel O. Functional polarization of human hepatoma HepaRG cells in response to forskolin. Sci Rep 2018; 8:16115. [PMID: 30382126 PMCID: PMC6208432 DOI: 10.1038/s41598-018-34421-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/08/2018] [Indexed: 02/04/2023] Open
Abstract
HepaRG is an original human hepatoma cell line, acquiring highly differentiated hepatic features when exposed to dimethylsulfoxide (DMSO). To search alternatives to DMSO, which may exert some toxicity, we have analyzed the effects of forskolin (FSK), a cAMP-generating agent known to favor differentiation of various cell types. FSK used at 50 µM for 3 days was found to promote polarization of high density-plated HepaRG cells, i.e., it markedly enhanced the formation of functional biliary canaliculi structures. It also increased expressions of various hepatic markers, including those of cytochrome P-450 (CYP) 3A4, of drug transporters like NTCP, OATP2B1 and BSEP, and of metabolism enzymes like glucose 6-phosphatase. In addition, FSK-treated HepaRG cells displayed enhanced activities of CYP3A4, NTCP and OATPs when compared to untreated cells. These polarizing/differentiating effects of FSK were next shown to reflect not only the generation of cAMP, but also the activation of the xenobiotic sensing receptors PXR and FXR by FSK. Co-treatment of HepaRG cells by the cAMP analog Sp-5,6-DCl-cBIMPS and the reference PXR agonist rifampicin reproduced the polarizing effects of FSK. Therefore, FSK may be considered as a relevant alternative to DMSO for getting polarized and differentiated HepaRG cells, notably for pharmacological and toxicological studies.
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Affiliation(s)
- Abdullah Mayati
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France
| | - Amélie Moreau
- Centre de Recherche en Pharmacocinétique, Technologie Servier, F-45000, Orléans, France
| | - Marc Le Vée
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France
| | - Arnaud Bruyère
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France
| | - Elodie Jouan
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France
| | - Claire Denizot
- Centre de Recherche en Pharmacocinétique, Technologie Servier, F-45000, Orléans, France
| | - Yannick Parmentier
- Centre de Recherche en Pharmacocinétique, Technologie Servier, F-45000, Orléans, France
| | - Olivier Fardel
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France. .,Pôle Biologie, Centre Hospitalier Universitaire, F-35033, Rennes, France.
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AMPK Activation of PGC-1α/NRF-1-Dependent SELENOT Gene Transcription Promotes PACAP-Induced Neuroendocrine Cell Differentiation Through Tolerance to Oxidative Stress. Mol Neurobiol 2018; 56:4086-4101. [DOI: 10.1007/s12035-018-1352-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/13/2018] [Indexed: 12/19/2022]
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15
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Mendieta I, Nuñez-Anita RE, Pérez-Sánchez G, Pavón L, Rodríguez-Cruz A, García-Alcocer G, Berumen LC. Effect of A549 neuroendocrine differentiation on cytotoxic immune response. Endocr Connect 2018; 7:791-802. [PMID: 29700099 PMCID: PMC5987362 DOI: 10.1530/ec-18-0145] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 04/26/2018] [Indexed: 12/29/2022]
Abstract
The present study was designed to determine the effects of factors secreted by the lung adenocarcinoma cell line with the neuroendocrine phenotype, A549NED, on cytotoxic T lymphocytes (CTLs) activity in vitro A perspective that integrates the nervous, endocrine and immune system in cancer research is essential to understand the complexity of dynamic interactions in tumours. Extensive clinical research suggests that neuroendocrine differentiation (NED) is correlated with worse patient outcomes; however, little is known regarding the effects of neuroendocrine factors on the communication between the immune system and neoplastic cells. The human lung cancer cell line A549 was induced to NED (A549NED) using cAMP-elevating agents. The A549NED cells showed changes in cell morphology, an inhibition of proliferation, an overexpression of chromogranin and a differential pattern of biogenic amine production (decreased dopamine and increased serotonin [5-HT] levels). Using co-cultures to determine the cytolytic CTLs activity on target cells, we showed that the acquisition of NED inhibits the decrease in the viability of the target cells and release of fluorescence. Additionally, the conditioned medium of A549NED and 5-HT considerably decreased the viability and proliferation of the Jurkat cells after 24 h. Thus, our study successfully generated a neuroendocrine phenotype from the A549 cell line. In co-cultures with CTLs, the pattern of secretion by A549NED impaired the proliferation and cytotoxic activity of CTLs, which might be partly explained by the increased release of 5-HT.
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Affiliation(s)
- Irasema Mendieta
- Facultad de QuímicaUniversidad Autónoma de Querétaro, Querétaro, Mexico
| | - Rosa Elvira Nuñez-Anita
- Facultad de Medicina Veterinaria y ZootecniaUniversidad Michoacana de San Nicolás Hidalgo, Morelia, Michoacán, Mexico
| | - Gilberto Pérez-Sánchez
- Departmento de PsicoimunologíaInstituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico
| | - Lenin Pavón
- Departmento de PsicoimunologíaInstituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico
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16
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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17
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Mutations in THAP1/DYT6 reveal that diverse dystonia genes disrupt similar neuronal pathways and functions. PLoS Genet 2018; 14:e1007169. [PMID: 29364887 PMCID: PMC5798844 DOI: 10.1371/journal.pgen.1007169] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 02/05/2018] [Accepted: 12/25/2017] [Indexed: 12/14/2022] Open
Abstract
Dystonia is characterized by involuntary muscle contractions. Its many forms are genetically, phenotypically and etiologically diverse and it is unknown whether their pathogenesis converges on shared pathways. Mutations in THAP1 [THAP (Thanatos-associated protein) domain containing, apoptosis associated protein 1], a ubiquitously expressed transcription factor with DNA binding and protein-interaction domains, cause dystonia, DYT6. There is a unique, neuronal 50-kDa Thap1-like immunoreactive species, and Thap1 levels are auto-regulated on the mRNA level. However, THAP1 downstream targets in neurons, and the mechanism via which it causes dystonia are largely unknown. We used RNA-Seq to assay the in vivo effect of a heterozygote Thap1 C54Y or ΔExon2 allele on the gene transcription signatures in neonatal mouse striatum and cerebellum. Enriched pathways and gene ontology terms include eIF2α Signaling, Mitochondrial Dysfunction, Neuron Projection Development, Axonal Guidance Signaling, and Synaptic LongTerm Depression, which are dysregulated in a genotype and tissue-dependent manner. Electrophysiological and neurite outgrowth assays were consistent with those enrichments, and the plasticity defects were partially corrected by salubrinal. Notably, several of these pathways were recently implicated in other forms of inherited dystonia, including DYT1. We conclude that dysfunction of these pathways may represent a point of convergence in the pathophysiology of several forms of inherited dystonia. Dystonia is a brain disorder that causes disabling involuntary muscle contractions and abnormal postures. Mutations in THAP1, a zinc-finger transcription factor, cause DYT6, but its neuronal targets and functions are unknown. In this study, we sought to determine the effects of Thap1C54Y and ΔExon2 alleles on the gene transcription signatures at postnatal day 1 (P1) in the mouse striatum and cerebellum in order to correlate function with specific genes or pathways. Our unbiased transcriptomics approach showed that Thap1 mutants revealed multiple signaling pathways involved in neuronal plasticity, axonal guidance, and oxidative stress response, which are also present in other forms of dystonia, particularly DYT1. We conclude that dysfunction of these pathways may represent a point of convergence on the pathogenesis of unrelated forms of inherited dystonia.
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18
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Pituitary adenylate cyclase activating polypeptide induces long-term, transcription-dependent plasticity and remodeling at autonomic synapses. Mol Cell Neurosci 2017; 85:170-182. [DOI: 10.1016/j.mcn.2017.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/19/2017] [Accepted: 10/06/2017] [Indexed: 12/28/2022] Open
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19
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Gopalakrishna R, Gundimeda U, Zhou S, Bui H, Davis A, McNeill T, Mack W. Laminin-1 induces endocytosis of 67KDa laminin receptor and protects Neuroscreen-1 cells against death induced by serum withdrawal. Biochem Biophys Res Commun 2017; 495:230-237. [PMID: 29108990 DOI: 10.1016/j.bbrc.2017.11.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/02/2017] [Indexed: 02/03/2023]
Abstract
Although the function of laminin in the basement membrane is known, the function of soluble "neuronal" laminin is unknown. Since laminin is neuroprotective, we determined whether the soluble laminin-1 induces signaling for neuroprotection via its 67KDa laminin-1 receptor (67LR). Treatment of Neuroscreen-1 (NS-1) cells with laminin-1 or YIGSR peptide, which corresponds to a sequence in laminin-1 β1 chain that binds to 67LR, induced a decrease in the cell-surface expression of 67LR and caused its internalization. Furthermore, intracellular cAMP-elevating agents, dibutyryl-cAMP, forskolin, and rolipram, also induced this internalization. Both soluble laminin-1 and YIGSR induced a sustained elevation of intracellular cAMP under defined conditions, suggesting a causal role of cAMP in the endocytosis of 67LR. This endocytosis was not observed in cells deficient in protein kinase A (PKA) nor in cells treated with either SQ 22536, an inhibitor for adenylyl cyclase, or ESI-09, an inhibitor for the exchange protein directly activated by cAMP (Epac). In addition, when internalization occurred in NS-1 cells, 67LR and adenylyl cyclase were localized in early endosomes. Under conditions in which endocytosis had occurred, both laminin-1 and YIGSR protected NS-1 cells from cell death induced by serum withdrawal. However, under conditions in which endocytosis did not occur, neither laminin-1 nor YIGSR protected these cells. Conceivably, the binding of laminin-1 to 67LR causes initial signaling through PKA and Epac, which causes the internalization of 67LR, along with signaling enzymes, such as adenylyl cyclase, into early endosomes. This causes sustained signaling for protection against cell death induced by serum withdrawal.
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Affiliation(s)
- Rayudu Gopalakrishna
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA.
| | - Usha Gundimeda
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA
| | - Sarah Zhou
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA
| | - Helena Bui
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA
| | - Andrew Davis
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA
| | - Thomas McNeill
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA
| | - William Mack
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA
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NCS-Rapgef2, the Protein Product of the Neuronal Rapgef2 Gene, Is a Specific Activator of D1 Dopamine Receptor-Dependent ERK Phosphorylation in Mouse Brain. eNeuro 2017; 4:eN-NWR-0248-17. [PMID: 28948210 PMCID: PMC5611689 DOI: 10.1523/eneuro.0248-17.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/21/2017] [Accepted: 08/26/2017] [Indexed: 01/11/2023] Open
Abstract
The neuritogenic cAMP sensor (NCS), encoded by the Rapgef2 gene, links cAMP elevation to activation of extracellular signal-regulated kinase (ERK) in neurons and neuroendocrine cells. Transducing human embryonic kidney (HEK)293 cells, which do not express Rapgef2 protein or respond to cAMP with ERK phosphorylation, with a vector encoding a Rapgef2 cDNA reconstituted cAMP-dependent ERK activation. Mutation of a single residue in the cyclic nucleotide-binding domain (CNBD) conserved across cAMP-binding proteins abrogated cAMP-ERK coupling, while deletion of the CNBD altogether resulted in constitutive ERK activation. Two types of mRNA are transcribed from Rapgef2 in vivo. Rapgef2 protein expression was limited to tissues, i.e., neuronal and endocrine, expressing the second type of mRNA, initiated exclusively from an alternative first exon called here exon 1’, and an alternative 5’ protein sequence leader fused to a common remaining open reading frame, which is termed here NCS-Rapgef2. In the male mouse brain, NCS-Rapgef2 is prominently expressed in corticolimbic excitatory neurons, and striatal medium spiny neurons (MSNs). Rapgef2-dependent ERK activation by the dopamine D1 agonist SKF81297 occurred in neuroendocrine neuroscreen-1 (NS-1) cells expressing the human D1 receptor and was abolished by deletion of Rapgef2. Corticolimbic [e.g., dentate gyrus (DG), basolateral amygdala (BLA)] ERK phosphorylation induced by SKF81297 was significantly attenuated in CamK2α-Cre+/−; Rapgef2cko/cko male mice. ERK phosphorylation in nucleus accumbens (NAc) MSNs induced by treatment with SKF81297, or the psychostimulants cocaine or amphetamine, was abolished in male Rapgef2cko/cko mice with NAc NCS-Rapgef2-depleting AAV-Synapsin-Cre injections. We conclude that D1-dependent ERK phosphorylation in mouse brain requires NCS-Rapgef2 expression.
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21
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Differential Pharmacophore Definition of the cAMP Binding Sites of Neuritogenic cAMP Sensor-Rapgef2, Protein Kinase A, and Exchange Protein Activated by cAMP in Neuroendocrine Cells Using an Adenine-Based Scaffold. ACS Chem Neurosci 2017; 8:1500-1509. [PMID: 28290664 DOI: 10.1021/acschemneuro.6b00462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We recently reported that the adenylate cyclase (AC) inhibitor SQ22,536 (9-tetrahydrofuranyl-adenine) also has inhibitory activity against the neuroendocrine-specific neuritogenic cAMP sensor-Rapgef2 (NCS-Rapgef2), a guanine nucleotide exchanger and activator for the small effector GTPase Rap1. Cell-based assays that distinguish signaling through the three intracellular cAMP sensors NCS-Rapgef2, exchange protein activated by cAMP (Epac), and protein kinase A (PKA), as well as AC, were used. These, collectively, assess the activities of adenine (6-amino-purine) derivatives modified at several positions to enhance selectivity for NCS-Rapgef2 by decreasing affinity for adenylate cyclase (AC), without increasing affinity for PKA or Epac. Testing of each adenine derivative in whole-cell assays incorporates features of cell permeability, target selectivity, and intrinsic potency into a single EC50 or IC50, making robust extrapolation to compound activity in vivo more likely. N6-MBC-cAMP is a selective PKA activator (EC50 = 265 μM) with low efficacy at NCS-Rapgef2. 8-CPT-2'-O-Me-cAMP and ESI-09 are confirmed as Epac-selective, for stimulation and inhibition, respectively, versus both PKA and NCS-Rapgef2. The compound N6-Phe-cAMP is a full agonist of NCS-Rapgef2 (EC50 = 256 μM). It has little or no activity against Epac or PKA. The compound N6-phenyl-9-tetrahydrofuranyladenine is a novel and potent NCS-Rapgef2 inhibitor without activity at PKA, Epac, or ACs, as assayed in the neuroendocrine NS-1 cell line. This line has been engineered to allow high-content screening for activation and inhibition of AC, PKA, Epac, and NCS-Rapgef2 and the cellular activities initiated by these signaling pathway protein components.
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Emery AC, Xu W, Eiden MV, Eiden LE. Guanine nucleotide exchange factor Epac2-dependent activation of the GTP-binding protein Rap2A mediates cAMP-dependent growth arrest in neuroendocrine cells. J Biol Chem 2017; 292:12220-12231. [PMID: 28546426 DOI: 10.1074/jbc.m117.790329] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 05/23/2017] [Indexed: 11/06/2022] Open
Abstract
First messenger-dependent activation of MAP kinases in neuronal and endocrine cells is critical for cell differentiation and function and requires guanine nucleotide exchange factor (GEF)-mediated activation of downstream Ras family small GTPases, which ultimately lead to ERK, JNK, and p38 phosphorylation. Because there are numerous GEFs and also a host of Ras family small GTPases, it is important to know which specific GEF-small GTPase dyad functions in a given cellular process. Here we investigated the upstream activators and downstream effectors of signaling via the GEF Epac2 in the neuroendocrine NS-1 cell line. Three cAMP sensors, Epac2, PKA, and neuritogenic cAMP sensor-Rapgef2, mediate distinct cellular outputs: p38-dependent growth arrest, cAMP response element-binding protein-dependent cell survival, and ERK-dependent neuritogenesis, respectively, in these cells. Previously, we found that cAMP-induced growth arrest of PC12 and NS-1 cells requires Epac2-dependent activation of p38 MAP kinase, which posed the important question of how Epac2 engages p38 without simultaneously activating other MAP kinases in neuronal and endocrine cells. We now show that the small GTP-binding protein Rap2A is the obligate effector for, and GEF substrate of, Epac2 in mediating growth arrest through p38 activation in NS-1 cells. This new pathway is distinctly parcellated from the G protein-coupled receptor → Gs → adenylate cyclase → cAMP → PKA → cAMP response element-binding protein pathway mediating cell survival and the G protein-coupled receptor → Gs → adenylate cyclase → cAMP → neuritogenic cAMP sensor-Rapgef2 → B-Raf → MEK → ERK pathway mediating neuritogenesis in NS-1 cells.
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Affiliation(s)
- Andrew C Emery
- Section on Molecular Neuroscience, National Institute of Mental Health Intramural Research Program, Bethesda, Maryland 20892
| | - Wenqin Xu
- Section on Molecular Neuroscience, National Institute of Mental Health Intramural Research Program, Bethesda, Maryland 20892
| | - Maribeth V Eiden
- Office of the Scientific Director, National Institute of Mental Health Intramural Research Program, Bethesda, Maryland 20892
| | - Lee E Eiden
- Section on Molecular Neuroscience, National Institute of Mental Health Intramural Research Program, Bethesda, Maryland 20892.
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Isensee J, Schild C, Schwede F, Hucho T. Crosstalk from cAMP to ERK1/2 emerges during postnatal maturation of nociceptive neurons and is maintained during aging. J Cell Sci 2017; 130:2134-2146. [PMID: 28515230 DOI: 10.1242/jcs.197327] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 05/10/2017] [Indexed: 02/02/2023] Open
Abstract
Maturation of nociceptive neurons depends on changes in transcription factors, ion channels and neuropeptides. Mature nociceptors initiate pain in part by drastically reducing the activation threshold via intracellular sensitization signaling. Whether sensitization signaling also changes during development and aging remains so far unknown. Using a novel automated microscopy approach, we quantified changes in intracellular signaling protein expression and in their signaling dynamics, as well as changes in intracellular signaling cascade wiring, in sensory neurons from newborn to senescent (24 months of age) rats. We found that nociceptive subgroups defined by the signaling components protein kinase A (PKA)-RIIβ (also known as PRKAR2B) and CaMKIIα (also known as CAMK2A) developed at around postnatal day 10, the time of nociceptor maturation. The integrative nociceptor marker, PKA-RIIβ, allowed subgroup segregation earlier than could be achieved by assessing the classical markers TRPV1 and Nav1.8 (also known as SCN10A). Signaling kinetics remained constant over lifetime despite in part strong changes in the expression levels. Strikingly, we found a mechanism important for neuronal memory - i.e. the crosstalk from cAMP and PKA to ERK1 and ERK2 (ERK1/2, also known as MAPK3 and MAPK1, respectively) - to emerge postnatally. Thus, maturation of nociceptors is closely accompanied by altered expression, activation and connectivity of signaling pathways known to be central for pain sensitization and neuronal memory formation.
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Affiliation(s)
- Joerg Isensee
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, Cologne D-50931, Germany
| | - Cosimo Schild
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, Cologne D-50931, Germany
| | - Frank Schwede
- BIOLOG Life Science Institute, Flughafendamm 9A, Bremen D-28199, Germany
| | - Tim Hucho
- Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, University Hospital of Cologne, Robert Koch Str. 10, Cologne D-50931, Germany
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24
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Wang P, Liu Z, Chen H, Ye N, Cheng X, Zhou J. Exchange proteins directly activated by cAMP (EPACs): Emerging therapeutic targets. Bioorg Med Chem Lett 2017; 27:1633-1639. [PMID: 28283242 PMCID: PMC5397994 DOI: 10.1016/j.bmcl.2017.02.065] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/07/2017] [Accepted: 02/26/2017] [Indexed: 11/22/2022]
Abstract
Exchange proteins directly activated by cAMP (EPACs) are critical cAMP-dependent signaling pathway mediators. The discovery of EPAC proteins has significantly facilitated understanding on cAMP-dependent signaling pathway and efforts along this line open new avenues for developing novel therapeutics for cancer, diabetes, heart failure, inflammation, infections, neurological disorders and other human diseases. Over the past decade, important progress has been made in the identification of EPAC agonists, antagonists and their biological and pharmacological applications. In this review, we briefly summarize recently reported novel functions of EPACs and the discovery of their small molecule modulators. The challenges and future perspectives are also discussed.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX 77030, United States
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States.
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25
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Polysulfides protect SH-SY5Y cells from methylglyoxal-induced toxicity by suppressing protein carbonylation: A possible physiological scavenger for carbonyl stress in the brain. Neurotoxicology 2016; 55:13-19. [PMID: 27163164 DOI: 10.1016/j.neuro.2016.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 05/01/2016] [Accepted: 05/05/2016] [Indexed: 12/25/2022]
Abstract
The formation of advanced glycation end products (AGEs) is associated with various neurological disorders, such as Alzheimer's disease, Parkinson's disease and schizophrenia. Methylglyoxal (MG), a highly reactive dicarbonyl compound, is known to be a major precursor for AGEs in modified proteins. Thus, a scavenger of MG might provide beneficial effects by suppressing the accumulation of AGEs and the occurrence of diseases induced by carbonyl stress. Meanwhile, polysulfides, one of the typical bound sulfur species, are oxidized forms of hydrogen sulfide (H2S) and may play a variety of roles in the brain. Herein, we assessed the scavenging ability of polysulfides against neuronal carbonyl stress induced by MG. First, we showed that polysulfides could protect differentiated (df)-SH-SY5Y cells from MG-induced cytotoxicity. When cells were pretreated with polysulfides, MG-induced cytotoxicity was attenuated with a rapid decrease in intracellular MG levels. Moreover, we found that polysulfides significantly suppressed the formation of MG-modified proteins in df-SH-SY5Y cells. Although polysulfide treatment increased endogenous GSH levels in the neuronal cells, its effects on MG-induced cytotoxicity were not affected by GSH concentration. Our results demonstrated that polysulfides had the direct potentials to protect neuronal cells against MG separate to the enzymatic detoxification system that required GSH.
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26
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Delgado-González E, Sánchez-Tusie AA, Morales G, Aceves C, Anguiano B. Triiodothyronine Attenuates Prostate Cancer Progression Mediated by β-Adrenergic Stimulation. Mol Med 2016; 22:1-11. [PMID: 26928389 DOI: 10.2119/molmed.2015.00047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 02/19/2016] [Indexed: 01/10/2023] Open
Abstract
Prostate cancer cells are responsive to adrenergic and thyroid stimuli. It is well established that β-adrenergic activation (protein kinase A [PKA]/cAMP response element binding protein [CREB]) promotes cancer progression, but the role of thyroid hormones is poorly understood. We analyzed the effects of β-adrenergic stimulation (isoproterenol [ISO]) and/or thyroid hormone on neuroendocrine (NE) differentiation and cell invasion, using in vivo (LNCaP tumor) and in vitro models (LNCaP and DU145 human cells). Nude mice were inoculated with LNCaP cells and were treated for 6 wks with ISO (200 μg/d), triiodothyronine (T3, 2.5 μg/d) or both. ISO alone reduced tumor growth but increased tumor expression of cAMP response element (CRE)-dependent genes (real-time polymerase chain reaction, chromogranin A, neuron-specific enolase, survivin, vascular endothelial growth factor [VEGF], urokinase plasmin activator [uPA] and metalloproteinase-9 [MMP-9]) and some proteins related to NE differentiation and/or invasiveness (synaptophysin, VEGF, pCREB). T3 reduced tumor growth and prevented the overexpression of ISO-stimulated factors through a pCREB-independent mechanism. In low invasive LNCaP cells, 50 μmol/L ISO or 100 nmol/L thyroxine (T4) induced the acquisition of NE-like morphology (phase-contrast microscopy), increased VEGF secretion (ELISA) and invasive capacity (Transwell assay), but no synergistic effects were observed after the coadministration of ISO + T4. In contrast, 10 nmol/L T3 alone had no effect, but it prevented the NE-like morphology and invasiveness stimulated by ISO. None of these treatments had any effect on highly invasive DU145 cells. In summary, this study showed that ISO and T4 increase cancer progression, and T3 attenuates ISO-stimulated progression. Further studies are required to determine if changes in the ratio of T4/T3 could be relevant for prostate cancer progression.
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Affiliation(s)
- Evangelina Delgado-González
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, México
| | - Ana Alicia Sánchez-Tusie
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, México
| | - Giapsy Morales
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, México
| | - Carmen Aceves
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, México
| | - Brenda Anguiano
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, México
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27
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Jiang SZ, Eiden LE. PACAPergic Synaptic Signaling and Circuitry Mediating Mammalian Responses to Psychogenic and Systemic Stressors. CURRENT TOPICS IN NEUROTOXICITY 2016. [DOI: 10.1007/978-3-319-35135-3_41] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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28
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Sugawara K, Shibasaki T, Takahashi H, Seino S. Structure and functional roles of Epac2 (Rapgef4). Gene 2015; 575:577-83. [PMID: 26390815 DOI: 10.1016/j.gene.2015.09.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/13/2015] [Accepted: 09/15/2015] [Indexed: 10/24/2022]
Abstract
Epac (exchange protein activated by cyclic-AMP) 2 is a direct target of 3'-5'-cyclic adenosine monophosphate (cAMP) and is involved in cAMP-mediated signal transduction through activation of the Ras-like small GTPase Rap. Crystallographic analyses revealed that activation of Epac2 by cAMP is accompanied by dynamic structural changes. Epac2 is expressed mainly in brain, neuroendocrine and endocrine tissues, and is involved in diverse cellular functions in the tissues. In this review, we summarize the structure and function of Epac2. We also discuss the physiological and pathophysiological roles of Epac2, and the possibility of Epac2 as a therapeutic target.
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Affiliation(s)
- Kenji Sugawara
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tadao Shibasaki
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
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del Pino J, Moyano-Cires PV, Anadon MJ, Díaz MJ, Lobo M, Capo MA, Frejo MT. Molecular Mechanisms of Amitraz Mammalian Toxicity: A Comprehensive Review of Existing Data. Chem Res Toxicol 2015; 28:1073-94. [DOI: 10.1021/tx500534x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Javier del Pino
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Paula Viviana Moyano-Cires
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Maria Jose Anadon
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - María Jesús Díaz
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Margarita Lobo
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Miguel Andrés Capo
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - María Teresa Frejo
- Departament of Toxicology
and Pharmacology, Veterinary School, and ‡Department of
Toxicology and Legal Medicine, Medicine School, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
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30
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Mazzio E, Georges B, McTier O, Soliman KFA. Neurotrophic Effects of Mu Bie Zi (Momordica cochinchinensis) Seed Elucidated by High-Throughput Screening of Natural Products for NGF Mimetic Effects in PC-12 Cells. Neurochem Res 2015; 40:2102-12. [PMID: 25862192 DOI: 10.1007/s11064-015-1560-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 12/22/2022]
Abstract
Post-mitotic central nervous system (CNS) neurons have limited capacity for regeneration, creating a challenge in the development of effective therapeutics for spinal cord injury or neurodegenerative diseases. Furthermore, therapeutic use of human neurotrophic agents such as nerve growth factor (NGF) are limited due to hampered transport across the blood brain barrier (BBB) and a large number of peripheral side effects (e.g. neuro-inflammatory pain/tissue degeneration etc.). Therefore, there is a continued need for discovery of small molecule NGF mimetics that can penetrate the BBB and initiate CNS neuronal outgrowth/regeneration. In the current study, we conduct an exploratory high-through-put (HTP) screening of 1144 predominantly natural/herb products (947 natural herbs/plants/spices, 29 polyphenolics and 168 synthetic drugs) for ability to induce neurite outgrowth in PC12 dopaminergic cells grown on rat tail collagen, over 7 days. The data indicate a remarkably rare event-low hit ratio with only 1/1144 tested substances (<111.25 µg/mL) being capable of inducing neurite outgrowth in a dose dependent manner, identified as; Mu Bie Zi, Momordica cochinchinensis seed extract (MCS). To quantify the neurotrophic effects of MCS, 36 images (n = 6) (average of 340 cells per image), were numerically assessed for neurite length, neurite count/cell and min/max neurite length in microns (µm) using Image J software. The data show neurite elongation from 0.07 ± 0.02 µm (controls) to 5.5 ± 0.62 µm (NGF 0.5 μg/mL) and 3.39 ± 0.45 µm (138 μg/mL) in MCS, where the average maximum length per group extended from 3.58 ± 0.42 µm (controls) to 41.93 ± 3.14 µm (NGF) and 40.20 ± 2.72 µm (MCS). Imaging analysis using immunocytochemistry (ICC) confirmed that NGF and MCS had similar influence on 3-D orientation/expression of 160/200 kD neurofilament, tubulin and F-actin. These latent changes were associated with early rise in phosphorylated extracellular signal-regulated kinase (ERK) p-Erk1 (T202/Y204)/p-Erk2 (T185/Y187) at 60 min with mild changes in pAKT peaking at 5 min, and no indication of pMEK involvement. These findings demonstrate a remarkable infrequency of natural products or polyphenolic constituents to exert neurotrophic effects at low concentrations, and elucidate a unique property of MCS extract to do so. Future research will be required to delineate in depth mechanism of action of MCS, constituents responsible and potential for therapeutic application in CNS degenerative disease or injury.
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Affiliation(s)
- E Mazzio
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Room 104, Dyson Pharmacy Building, 1520 ML King Blvd, Tallahassee, FL, 32307, USA
| | - B Georges
- Department of Biology, Florida A&M University, Tallahassee, FL, 32307, USA
| | - O McTier
- Department of Biology, Florida A&M University, Tallahassee, FL, 32307, USA
| | - Karam F A Soliman
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Room 104, Dyson Pharmacy Building, 1520 ML King Blvd, Tallahassee, FL, 32307, USA.
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Emery AC, Liu XH, Xu W, Eiden MV, Eiden LE. Cyclic Adenosine 3',5'-Monophosphate Elevation and Biological Signaling through a Secretin Family Gs-Coupled G Protein-Coupled Receptor Are Restricted to a Single Adenylate Cyclase Isoform. Mol Pharmacol 2015; 87:928-35. [PMID: 25769305 DOI: 10.1124/mol.115.098087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/12/2015] [Indexed: 12/11/2022] Open
Abstract
PC12 cells express five adenylate cyclase (AC) isoforms, most abundantly AC6 and AC7. These two ACs were individually silenced using lentiviral short hairpin RNAs, which lead to a decrease (≥80%) of the protein product of each transcript. These stable PC12 sublines were then used to examine potential AC isoform preference for signaling through a family B G protein-coupled receptor (GPCR). Cells were challenged with the endogenous agonist of the pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1), pituitary adenylate cyclase-activating polypeptide (PACAP)-38, or the diterpene forskolin as an AC-proximal control. Intracellular cAMP levels were elevated by forskolin about equally in wild-type, AC6, and AC7 knockdown cells. The ability of PACAP-38 and forskolin to activate three cAMP sensors downstream of AC [protein kinase A (PKA), exchange protein activated by cAMP (Epac) 2/Rapgef4, and neuritogenic cAMP sensor (NCS)/Rapgef2] was examined by monitoring the phosphorylation status of their respective targets, cAMP response element-binding protein, p38, and extracellular signal-regulated kinase. Forskolin stimulation of each downstream target of cAMP was unaffected by knockdown of either AC6 or AC7. PACAP-38 activation of all downstream targets of cAMP was unaffected by AC7 knockdown, but abolished following AC6 knockdown. Membrane cholesterol depletion with methyl-β-cyclodextrin mimicked the effects of AC6 silencing on PACAP signaling, without attenuating forskolin signaling. These data suggest that vicinal constraint of the GPCR PAC1 and AC6 determines the exclusive requirement for this AC in PACAP signaling, but that the coupling of the cAMP sensors PKA, Epac2/Rapgef4, and NCS/Rapgef2, to their respective downstream signaling targets, determines how cAMP signaling is parcellated to physiologic responses, such as neuritogenesis, upon GPCR-Gs activation in neuroendocrine cells.
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Affiliation(s)
- Andrew C Emery
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Xiu-Huai Liu
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Wenqin Xu
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Maribeth V Eiden
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Lee E Eiden
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
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32
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Cytoskeletal and signaling mechanisms of neurite formation. Cell Tissue Res 2014; 359:267-78. [PMID: 25080065 DOI: 10.1007/s00441-014-1955-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
Abstract
The formation of a neurite, the basis for axons and dendrites, begins with the concerted accumulation and organization of actin and microtubules. Whereas much is known about the proteins that play a role in these processes, because they perform similar functions in axon branching and filopodia formation, much remains to be discovered concerning the interaction of these individual cytoskeletal regulators during neurite formation. Here, we review the literature regarding various models of filopodial formation and the way in which proteins that control actin organization and polymerization induce neurite formation. Although several different regulators of actin polymerization are involved in neurite initiation, redundancy occurs between these regulators, as the effects of the loss of a single regulator can be mitigated by the addition of neurite-promoting substrates and proteins. Similar to actin dynamics, both microtubule stabilizing and destabilizing proteins play a role in neurite initiation. Furthermore, interactions between the actin and microtubule cytoskeleton are required for neurite formation. Several lines of evidence indicate that the interactions between these two components of the cytoskeleton are needed for force generation and for the localization of microtubules at sites of nascent neurites. The general theme that emerges is the existence of several central regulatory pathways on which extracellular cues converge to control and organize both actin and microtubules to induce the formation of neurites.
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