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Effects of Pacap on Schwann Cells: Focus on Nerve Injury. Int J Mol Sci 2020; 21:ijms21218233. [PMID: 33153152 PMCID: PMC7663204 DOI: 10.3390/ijms21218233] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/23/2020] [Accepted: 11/02/2020] [Indexed: 12/27/2022] Open
Abstract
Schwann cells, the most abundant glial cells of the peripheral nervous system, represent the key players able to supply extracellular microenvironment for axonal regrowth and restoration of myelin sheaths on regenerating axons. Following nerve injury, Schwann cells respond adaptively to damage by acquiring a new phenotype. In particular, some of them localize in the distal stump to form the Bungner band, a regeneration track in the distal site of the injured nerve, whereas others produce cytokines involved in recruitment of macrophages infiltrating into the nerve damaged area for axonal and myelin debris clearance. Several neurotrophic factors, including pituitary adenylyl cyclase-activating peptide (PACAP), promote survival and axonal elongation of injured neurons. The present review summarizes the evidence existing in the literature demonstrating the autocrine and/or paracrine action exerted by PACAP to promote remyelination and ameliorate the peripheral nerve inflammatory response following nerve injury.
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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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Genaro-Mattos TC, Anderson A, Allen LB, Korade Z, Mirnics K. Cholesterol Biosynthesis and Uptake in Developing Neurons. ACS Chem Neurosci 2019; 10:3671-3681. [PMID: 31244054 PMCID: PMC7184320 DOI: 10.1021/acschemneuro.9b00248] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Brain cholesterol biosynthesis, a separate and distinct process from whole-body cholesterol homeostasis, starts during embryonic development. To gain a better understanding of the neuronal and glial contributions to the brain cholesterol pool, we studied this process in control, Dhcr7-/-, and Dhcr24-/- cell cultures. Our LC-MS/MS method allowed us to measure several different sterol intermediates and cholesterol during neuronal differentiation. We found that developing cortical neurons rely on endogenous cholesterol synthesis and utilize ApoE-complexed cholesterol and sterol precursors from their surroundings. Both developing neurons and astrocytes release cholesterol into their local environment. Our studies also uncovered that developing neurons produced significantly higher amounts of cholesterol per cell than the astrocytes. Finally, we established that both neurons and astroglia preferentially use the Bloch sterol biosynthesis pathway, where desmosterol is the immediate precursor to cholesterol. Overall, our studies suggest that endogenous sterol synthesis in developing neurons is a critical and complexly regulated homeostatic process during brain development.
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Affiliation(s)
- Thiago C. Genaro-Mattos
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68105, United States
| | - Allison Anderson
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68105, United States
| | - Luke B. Allen
- Department of Pediatrics, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Zeljka Korade
- Department of Pediatrics, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States,Corresponding Authors:.
| | - Károly Mirnics
- Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68105, United States,Corresponding Authors:.
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Jiang M, Zhuang Y, Zu WC, Jiao L, Richard SA, Zhang S. Overexpression of EPAC2 reduces the invasion of glioma cells via MMP-2. Oncol Lett 2019; 17:5080-5086. [PMID: 31186720 PMCID: PMC6507491 DOI: 10.3892/ol.2019.10200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/26/2019] [Indexed: 01/15/2023] Open
Abstract
Exchange proteins directly activated by cAMP (EPACs) are crucial cyclic adenosine 3′,5′-monophosphate- determined signaling pathway intercessors, which are associated with the pathogenesis of neurological disorders and numerous human diseases. To the best of our knowledge, the role of EPAC2 signaling via matrix metalloproteinase 2 (MMP-2) in the pathogenesis of glioma has not been studied. Therefore, the present study focused on the role of EPAC2 in glioma, and assessed the invasiveness of human glioma cell lines following EPAC2 overexpression. Expression levels of EPAC2 in normal brain tissues and clinical glioma specimens were detected by western blotting. An EPAC2 overexpression vector was transfected into U251 and U87 cell lines to increase the expression levels of EPAC2. Expression levels of MMP-2 were detected by western blotting, and the invasive abilities of glioma cells were detected by a Transwell assay. EPAC2 was relatively highly expressed in normal brain tissue, while EPAC2 expression was significantly decreased in clinical glioma specimens (P<0.01). In vitro transfection of EPAC2 overexpression vector significantly reduced the MMP-2 protein levels of glioma cells, and, at the same time, the invasive cell number was significantly decreased in a Transwell assay. The present study demonstrated that MMP-2 regulation via EPAC2 overexpression is a novel promising therapeutic route in malignant types of glioma.
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Affiliation(s)
- Ming Jiang
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China.,Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Yan Zhuang
- Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Wang-Cun Zu
- Department of Neurosurgery, Northern Jiangsu People's Hospital, Yangzhou University, Yangzhou, Jiangsu 225000, P.R. China
| | - Lei Jiao
- Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Seidu A Richard
- Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China.,Department of Immunology, Jiangsu University, Zhenjiang, Jiangsu 212013, P.R. China.,Department of Medicine, Princefield University, P.O. Box MA 128, Ho, Volta Region, Ghana
| | - Shiming Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
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Wang GY, Li L, Liu B, Han X, Wang CH, Wang JW. Integrated bioinformatic analysis unveils significant genes and pathways in the pathogenesis of supratentorial primitive neuroectodermal tumor. Onco Targets Ther 2018; 11:1849-1859. [PMID: 29670360 PMCID: PMC5894672 DOI: 10.2147/ott.s148776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Purpose This study aimed to explore significant genes and pathways involved in the pathogenesis of supratentorial primitive neuroectodermal tumor (sPNET). Materials and methods Gene expression profile of GSE14295 was downloaded from publicly available Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened out in primary sPNET samples compared with normal fetal and adult brain reference samples (sPNET vs fetal brain and sPNET vs adult brain). Pathway enrichment analysis of these DEGs was conducted, followed by protein–protein interaction (PPI) network construction and significant module selection. Additionally, transcription factors (TFs) regulating the common DEGs in the two comparison groups were identified, and the regulatory network was constructed. Results In total, 526 DEGs (99 up- and 427 downregulated) in sPNET vs fetal brain and 815 DEGs (200 up- and 615 downregulated) in sPNET vs adult brain were identified. DEGs in sPNET vs fetal brain and sPNET vs adult brain were associated with calcium signaling pathway, cell cycle, and p53 signaling pathway. CDK1, CDC20, BUB1B, and BUB1 were hub nodes in the PPI networks of DEGs in sPNET vs fetal brain and sPNET vs adult brain. Significant modules were extracted from the PPI networks. In addition, 64 upregulated and 200 downregulated overlapping DEGs were identified in both sPNET vs fetal brain and sPNET vs adult brain. The genes involved in the regulatory network upon overlapping DEGs and the TFs were correlated with calcium signaling pathway. Conclusion Calcium signaling pathway and several genes (CDK1, CDC20, BUB1B, and BUB1) may play important roles in the pathogenesis of sPNET.
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Affiliation(s)
| | - Ling Li
- Department of Pediatrics, Qilu Children's Hospital of Shandong University, Jinan, Shandong
| | - Bo Liu
- Department of Neurosurgery
| | | | | | - Ji-Wen Wang
- Department of Neurology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Pudong New District, Shanghai, People's Republic of China
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Rivnyak A, Kiss P, Tamas A, Balogh D, Reglodi D. Review on PACAP-Induced Transcriptomic and Proteomic Changes in Neuronal Development and Repair. Int J Mol Sci 2018; 19:ijms19041020. [PMID: 29596316 PMCID: PMC5979407 DOI: 10.3390/ijms19041020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 12/19/2022] Open
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread occurrence and diverse biological effects. Among its several different effects, of special importance is the action of PACAP on neuronal proliferation, differentiation and migration, and neuroprotection. The neuroprotective mechanism of PACAP is both direct and indirect, via neuronal and non-neuronal cells. Several research groups have performed transcriptomic and proteomic analysis on PACAP-mediated genes and proteins. Hundreds of proteins have been described as being involved in the PACAP-mediated neuroprotection. In the present review we summarize the few currently available transcriptomic data potentially leading to the proteomic changes in neuronal development and protection. Proteomic studies focusing on the neuroprotective role of PACAP are also reviewed and discussed in light of the most intriguing and promising effect of this neuropeptide, which may possibly have future therapeutic potential.
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Affiliation(s)
- Adam Rivnyak
- Department of Anatomy, MTA-PTE PACAP Research Team, Neuroscience Centre, University of Pecs Medical School, 7624 Pécs, Hungary.
| | - Peter Kiss
- Department of Anatomy, MTA-PTE PACAP Research Team, Neuroscience Centre, University of Pecs Medical School, 7624 Pécs, Hungary.
| | - Andrea Tamas
- Department of Anatomy, MTA-PTE PACAP Research Team, Neuroscience Centre, University of Pecs Medical School, 7624 Pécs, Hungary.
| | - Dorottya Balogh
- Department of Anatomy, MTA-PTE PACAP Research Team, Neuroscience Centre, University of Pecs Medical School, 7624 Pécs, Hungary.
| | - Dora Reglodi
- Department of Anatomy, MTA-PTE PACAP Research Team, Neuroscience Centre, University of Pecs Medical School, 7624 Pécs, Hungary.
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Seo H, Lee K. Epac2 contributes to PACAP-induced astrocytic differentiation through calcium ion influx in neural precursor cells. BMB Rep 2016; 49:128-33. [PMID: 26645637 PMCID: PMC4915117 DOI: 10.5483/bmbrep.2016.49.2.202] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 11/30/2022] Open
Abstract
Astrocytes play a critical role in normal brain functions and maintaining the brain microenvironment, and defects in astrocytogenesis during neurodevelopment could give rise to severe mental illness and psychiatric disorders. During neuro-embryogenesis, astrocytogenesis involves astrocytic differentiation of neural precursor cells (NPCs) induced by signals from ciliary neurotrophic factor (CNTF) or pituitary adenylate cyclase-activating peptide (PACAP). However, in contrast to the CNTF signaling pathway, the exact mechanism underlying astrocytic differentiation induced by PACAP is unknown. In the present study, we aimed to verify a signaling pathway specific to PACAP-induced astrocytogenesis, using exchange protein directly activated by cAMP2 (Epac2)-knockout mice. We found that PACAP could trigger astrocytic differentiation of NPCs via Epac2 activation and an increase in the intracellular calcium concentration via a calcium ion influx. Taken together, we concluded that astrocytogenesis stimulated by PACAP occurs through a novel signaling pathway independent from CNTF-JAK/STAT signaling, that is the well-known pathway of astrocytogenesis. [BMB Reports 2016; 49(2): 128-133]
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Affiliation(s)
- Hyunhyo Seo
- Department of Anatomy, Brain Science & Engineering Institute, Kyungpook National University Graduate School of Medicine, Daegu 41944, Korea
| | - Kyungmin Lee
- Department of Anatomy, Brain Science & Engineering Institute, Kyungpook National University Graduate School of Medicine, Daegu 41944, Korea
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Maduna T, Lelievre V. Neuropeptides shaping the central nervous system development: Spatiotemporal actions of VIP and PACAP through complementary signaling pathways. J Neurosci Res 2016; 94:1472-1487. [PMID: 27717098 DOI: 10.1002/jnr.23915] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/04/2016] [Accepted: 08/15/2016] [Indexed: 01/18/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are neuropeptides with wide, complementary, and overlapping distributions in the central and peripheral nervous systems, where they exert important regulatory roles in many physiological processes. VIP and PACAP display a large range of biological cellular targets and functions in the adult nervous system including regulation of neurotransmission and neuroendocrine secretion and neuroprotective and neuroimmune responses. As the main focus of the present review, VIP and PACAP also have been long implicated in nervous system development and maturation through their interaction with the seven transmembrane domain G protein-coupled receptors, PAC1, VPAC1, and VPAC2, initiating multiple signaling pathways. Compared with PAC1, which solely binds PACAP with very high affinity, VPACs exhibit high affinities for both VIP and PACAP but differ from each other because of their pharmacological profile for both natural accessory peptides and synthetic or chimeric molecules, with agonistic and antagonistic properties. Complementary to initial pharmacological studies, transgenic animals lacking these neuropeptides or their receptors have been used to further characterize the neuroanatomical, electrophysiological, and behavioral roles of PACAP and VIP in the developing central nervous system. In this review, we recapitulate the critical steps and processes guiding/driving neurodevelopment in vertebrates and superimposing the potential contribution of PACAP and VIP receptors on the given timeline. We also describe how alterations in VIP/PACAP signaling may contribute to both (neuro)developmental and adult pathologies and suggest that tuning of VIP/PACAP signaling in a spatiotemporal manner may represent a novel avenue for preventive therapies of neurological and psychiatric disorders. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Tando Maduna
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique UPR3212, Université de Strasbourg, Strasbourg, France
| | - Vincent Lelievre
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique UPR3212, Université de Strasbourg, Strasbourg, France.
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Kanski R, van Strien ME, van Tijn P, Hol EM. A star is born: new insights into the mechanism of astrogenesis. Cell Mol Life Sci 2014; 71:433-47. [PMID: 23907612 PMCID: PMC11113452 DOI: 10.1007/s00018-013-1435-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/10/2013] [Accepted: 07/22/2013] [Indexed: 12/22/2022]
Abstract
Astrocytes emerge as crucial cells for proper neuronal functioning in the developing and adult brain. Neurons and astrocytes are sequentially generated from the same pool of neural stem cells (NSCs). Tight regulation of the neuron-to-astrocyte switch is critical for (1) the generation of a balanced number of astrocytes and neurons and (2) neuronal circuit formation, since newborn astrocytes regulate synapse formation. This review focuses on signaling pathways that instruct astrogenesis, incorporating recently discovered intrinsic and extrinsic regulators. The canonical pathway of astrocytic gene expression, JAK/STAT signaling, is inhibited during neurogenesis to prevent premature astrocyte differentiation. At the onset of astrogenesis, Notch signaling induces epigenetic remodeling of astrocytic genes like glial fibrillary acidic protein to change NSC competence. In turn, astrogenesis is initiated by signals received from newborn neurons. We highlight how key molecular pathways like JAK/STAT and Notch are integrated in a complex network of environmental signals and epigenetic and transcriptional regulators to determine NSC differentiation. It is essential to understand NSC differentiation in respect to future NSC-based therapies for brain diseases, as transplanted NSCs preferentially become astrocytes. As emphasized in this review, many clues in this respect can be learned from development.
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Affiliation(s)
- Regina Kanski
- Astrocyte Biology and Neurodegeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Miriam E. van Strien
- Astrocyte Biology and Neurodegeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Paula van Tijn
- Astrocyte Biology and Neurodegeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
- Hubrecht Institute, an Institute of the Royal Netherlands Academy of Arts and Sciences, Utrecht, The Netherlands
| | - Elly M. Hol
- Astrocyte Biology and Neurodegeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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Tung YT, Wang BJ, Hsu WM, Hu MK, Her GM, Huang WP, Liao YF. Presenilin-1 regulates the expression of p62 to govern p62-dependent tau degradation. Mol Neurobiol 2013; 49:10-27. [PMID: 23794287 DOI: 10.1007/s12035-013-8482-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 06/04/2013] [Indexed: 12/23/2022]
Abstract
Mutations in presenilin-1 (PS1) are tightly associated with early-onset familial Alzheimer's disease (FAD), which is characterized by extracellular amyloid plaques and the accumulation of intracellular Tau. In addition to being the catalytic subunit of γ-secretase, PS1 has been shown to regulate diverse cellular functions independent of its proteolytic activity. We found that cells deficient in PS1 exhibit reduced levels of p62 protein, a cargo-receptor shuttling Tau for degradation. The downregulation of PS1 led to a significant decrease in both the protein and mRNA transcript of p62, concomitant with attenuated p62 promoter activity. This PS1-dependent regulation of p62 expression was mediated through an Akt/AP-1 pathway independent of the proteolytic activity of PS1/γ-secretase. This p62-mediated Tau degradation was significantly impaired in PS1-deficient cells, which can be rescued by ectopic expression of either p62 or wild-type PS1 but not mutant PS1 containing FAD-linked mutations. Our study suggests a novel function for PS1 in modulating p62 expression to control the proteostasis of Tau.
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Affiliation(s)
- Ying-Tsen Tung
- Laboratory of Molecular Neurobiology, Institute of Cellular and Organismic Biology, Academia Sinica, 128 Sec. 2 Academia Rd, Taipei, 11529, Taiwan
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11
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DREAM regulates insulin promoter activity through newly identified DRE element. Open Life Sci 2013. [DOI: 10.2478/s11535-013-0123-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AbstractDownstream regulatory element antagonist modulator (DREAM) protein is a 31 kDa Ca2+-regulated transcriptional repressor. It functions as a silencer of the gene transcription. In low intracellular free Ca2+ concentration DREAM tightly binds to the downstream regulatory element (DRE) of gene promoter and impedes the transcription. In higher Ca2+ concentrations DREAM binds Ca2+ and disconnects from DRE of the gene promoter enabling transcription. We report that DREAM is expressed in different human tissues including the pancreas, where it is located in the islets of Langerhans. Location of DREAM in RIN-F5 cells in cultures is restricted to the nucleus and membranes and changes after increased Ca2+-levels. The proteins dissociate from dimmers to monomers and translocate out of the nucleus. The expression of DREAM in β-cells in the islets of Langerhans regulates the promoter activity of the insulin gene by directly interacting with the sequence located between +52 bp and +81 bp downstream of the transcriptional start site of the promoter. Our results provide evidence for the existence of DRE sequence in the insulin gene promoter. It is suggested that DREAM is a repressor of insulin gene transcription, whose effect is mediated by direct binding to DRE sequence.
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Blechman J, Levkowitz G. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity. Front Endocrinol (Lausanne) 2013; 4:55. [PMID: 23734144 PMCID: PMC3659299 DOI: 10.3389/fendo.2013.00055] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 04/24/2013] [Indexed: 12/11/2022] Open
Abstract
Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.
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Affiliation(s)
- Janna Blechman
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
| | - Gil Levkowitz
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
- *Correspondence: Gil Levkowitz, Department of Molecular Cell Biology, Weizmann Institute of Science, P. O. Box 26, Rehovot 76100, Israel. e-mail:
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Hamdi Y, Kaddour H, Vaudry D, Bahdoudi S, Douiri S, Leprince J, Castel H, Vaudry H, Tonon MC, Amri M, Masmoudi-Kouki O. The octadecaneuropeptide ODN protects astrocytes against hydrogen peroxide-induced apoptosis via a PKA/MAPK-dependent mechanism. PLoS One 2012; 7:e42498. [PMID: 22927932 PMCID: PMC3424241 DOI: 10.1371/journal.pone.0042498] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 07/06/2012] [Indexed: 12/18/2022] Open
Abstract
Astrocytes synthesize and release endozepines, a family of regulatory peptides, including the octadecaneuropeptide (ODN) an endogenous ligand of both central-type benzodiazepine (CBR) and metabotropic receptors. We have recently shown that ODN exerts a protective effect against hydrogen peroxide (H2O2)-induced oxidative stress in astrocytes. The purpose of the present study was to determine the type of receptor and the transduction pathways involved in the protective effect of ODN in cultured rat astrocytes. We have first observed a protective activity of ODN at very low concentrations that was abrogated by the metabotropic ODN receptor antagonist cyclo1–8[DLeu5]OP, but not by the CBR antagonist flumazenil. We have also found that the metabotropic ODN receptor is positively coupled to adenylyl cyclase in astrocytes and that the glioprotective action of ODN upon H2O2-induced astrocyte death is PKA- and MEK-dependent, but PLC/PKC-independent. Downstream of PKA, ODN induced ERK phosphorylation, which in turn activated the expression of the anti-apoptotic gene Bcl-2 and blocked the stimulation by H2O2 of the pro-apoptotic gene Bax. The effect of ODN on the Bax/Bcl-2 balance contributed to abolish the deleterious action of H2O2 on mitochondrial membrane integrity and caspase-3 activation. Finally, the inhibitory effect of ODN on caspase-3 activity was shown to be PKA and MEK-dependent. In conclusion, the present results demonstrate that the potent glioprotective action of ODN against oxidative stress involves the metabotropic ODN receptor coupled to the PKA/ERK-kinase pathway to inhibit caspase-3 activation.
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Affiliation(s)
- Yosra Hamdi
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Hadhemi Kaddour
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - David Vaudry
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
- International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France
- Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), Institute for Medical Research and Innovation (IRIB), University of Rouen, Mont-Saint-Aignan, France
| | - Seyma Bahdoudi
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Salma Douiri
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Jérôme Leprince
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
- International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France
- Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), Institute for Medical Research and Innovation (IRIB), University of Rouen, Mont-Saint-Aignan, France
| | - Helene Castel
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
| | - Hubert Vaudry
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
- International Associated Laboratory Samuel de Champlain, Mont-Saint-Aignan, France
- Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), Institute for Medical Research and Innovation (IRIB), University of Rouen, Mont-Saint-Aignan, France
- * E-mail: (MA), (HV)
| | - Marie-Christine Tonon
- Inserm U982, Laboratory of Neuronal and Neuroendocrine Communication and Differentiation, University of Rouen, Mont-Saint-Aignan, France
| | - Mohamed Amri
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
- * E-mail: (MA), (HV)
| | - Olfa Masmoudi-Kouki
- Laboratory of Functional Neurophysiology and Pathology, Research Unit UR/11ES09, Department of Biological Sciences, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
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Abstract
Cholesterol is an essential membrane component enriched in plasma membranes, growth cones, and synapses. The brain normally synthesizes all cholesterol locally, but the contribution of individual cell types to brain cholesterol metabolism is unknown. To investigate whether cortical projection neurons in vivo essentially require cholesterol biosynthesis and which cell types support neurons, we have conditionally ablated the cholesterol biosynthesis in these neurons in mice either embryonically or postnatally. We found that cortical projection neurons synthesize cholesterol during their entire lifetime. At all stages, they can also benefit from glial support. Adult neurons that lack cholesterol biosynthesis are mainly supported by astrocytes such that their functional integrity is preserved. In contrast, microglial cells support young neurons. However, compensatory efforts of microglia are only transient leading to layer-specific neuronal death and the reduction of cortical projections. Hence, during the phase of maximal membrane growth and maximal cholesterol demand, neuronal cholesterol biosynthesis is indispensable. Analysis of primary neurons revealed that neurons tolerate only slight alteration in the cholesterol content and plasma membrane tension. This quality control allows neurons to differentiate normally and adjusts the extent of neurite outgrowth, the number of functional growth cones and synapses to the available cholesterol. This study highlights both the flexibility and the limits of horizontal cholesterol transfer in vivo and may have implications for the understanding of neurodegenerative diseases.
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Nitric Oxide Modulated the Expression of DREAM/Calsenilin/KChIP3 in Inflammatory Pain of Rats. Inflammation 2012; 35:1867-71. [DOI: 10.1007/s10753-012-9508-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Leclerc C, Néant I, Moreau M. The calcium: an early signal that initiates the formation of the nervous system during embryogenesis. Front Mol Neurosci 2012; 5:3. [PMID: 22593733 PMCID: PMC3351002 DOI: 10.3389/fnmol.2012.00064] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/25/2012] [Indexed: 01/19/2023] Open
Abstract
The calcium (Ca(2+)) signaling pathways have crucial roles in development from fertilization through differentiation to organogenesis. In the nervous system, Ca(2+) signals are important regulators for various neuronal functions, including formation and maturation of neuronal circuits and long-term memory. However, Ca(2+) signals are also involved in the earliest steps of neurogenesis including neural induction, differentiation of neural progenitors into neurons, and the neuro-glial switch. This review examines when and how Ca(2+) signals are generated during each of these steps with examples taken from in vivo studies in vertebrate embryos and from in vitro assays using embryonic and neural stem cells (NSCs). During the early phases of neurogenesis few investigations have been performed to study the downstream targets of Ca(2+) which posses EF-hand in their structure. This opens an entire field of research. We also discuss the highly specific nature of the Ca(2+) signaling pathway and its interaction with the other signaling pathways involved in early neural development.
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Affiliation(s)
- Catherine Leclerc
- Centre de Biologie du Développement, Université Toulouse III, CNRS UMR 5547Toulouse, France and GDRE n731, “Ca toolkit coded proteins as drug targets in animal and plant cells”
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Rasd1 modulates the coactivator function of NonO in the cyclic AMP pathway. PLoS One 2011; 6:e24401. [PMID: 21915321 PMCID: PMC3168489 DOI: 10.1371/journal.pone.0024401] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 08/08/2011] [Indexed: 11/19/2022] Open
Abstract
All living organisms exhibit autonomous daily physiological and behavioural rhythms to help them synchronize with the environment. Entrainment of circadian rhythm is achieved via activation of cyclic AMP (cAMP) and mitogen-activated protein kinase signaling pathways. NonO (p54nrb) is a multifunctional protein involved in transcriptional activation of the cAMP pathway and is involved in circadian rhythm control. Rasd1 is a monomeric G protein implicated to play a pivotal role in potentiating both photic and nonphotic responses of the circadian rhythm. In this study, we have identified and validated NonO as an interacting partner of Rasd1 via affinity pulldown, co-immunoprecipitation and indirect immunofluorescence studies. The GTP-hydrolysis activity of Rasd1 is required for the functional interaction. Functional interaction of Rasd1-NonO in the cAMP pathway was investigated via reporter gene assays, chromatin immunoprecipitation and gene knockdown. We showed that Rasd1 and NonO interact at the CRE-site of specific target genes. These findings reveal a novel mechanism by which the coregulator activity of NonO can be modulated.
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18
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Leclerc C, Néant I, Moreau M. Early neural development in vertebrates is also a matter of calcium. Biochimie 2011; 93:2102-11. [PMID: 21742011 DOI: 10.1016/j.biochi.2011.06.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 06/24/2011] [Indexed: 12/19/2022]
Abstract
The calcium (Ca(2+)) signaling pathways have crucial roles in development from fertilization through differentiation to organogenesis. In the nervous system, Ca(2+) signals are important regulators for various neuronal functions, including formation and maturation of neuronal circuits and long-term memory. However, Ca(2+) signals are mainly involved in the earliest steps of nervous system development including neural induction, differentiation of neural progenitors into neurons, and the neuro-glial switch. This review examines when and how Ca(2+) signals are generated during each of these steps with examples taken from in vivo studies in vertebrate embryos and from in vitro assays using embryonic and neural stem cells. Also discussed is the highly specific nature of the Ca(2+) signaling pathway and its interaction with the other signaling pathways involved in early neural development.
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Affiliation(s)
- Catherine Leclerc
- Centre de Biologie du Développement, UMR CNRS 5547 and GDR 2688, Université de Toulouse, 118 route de Narbonne, Toulouse, France.
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