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Ahmed J, Meszaros A, Lazar T, Tompa P. DNA-binding domain as the minimal region driving RNA-dependent liquid-liquid phase separation of androgen receptor. Protein Sci 2021; 30:1380-1392. [PMID: 33938068 PMCID: PMC8197421 DOI: 10.1002/pro.4100] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/19/2022]
Abstract
Androgen receptor (AR) is a nuclear hormone receptor that regulates the transcription of genes involved in the development of testis, prostate and the nervous system. Misregulation of AR is a major driver of prostate cancer (PC). The primary agonist of full-length AR is testosterone, whereas its splice variants, for example, AR-v7 implicated in cancer may lack a ligand-binding domain and are thus devoid of proper hormonal control. Recently, it was demonstrated that full-length AR, but not AR-v7, can undergo liquid-liquid phase separation (LLPS) in a cellular model of PC. In a detailed bioinformatics and deletion analysis, we have analyzed which AR region is responsible for LLPS. We found that its DNA-binding domain (DBD) can bind RNA and can undergo RNA-dependent LLPS. RNA regulates its LLPS in a reentrant manner, that is, it has an inhibitory effect at higher concentrations. As RNA binds DBD more weakly than DNA, while both RNA and DNA localizes into AR droplets, its LLPS depends on the relative concentration of the two nucleic acids. The region immediately preceding DBD has no effect on the LLPS propensity of AR, whereas the functional part of its long N-terminal disordered transactivation domain termed activation function 1 (AF1) inhibits AR-v7 phase separation. We suggest that the resulting diminished LLPS tendency of AR-v7 may contribute to the misregulation of the transcription function of AR in prostate cancer.
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Affiliation(s)
- Junaid Ahmed
- VIB‐VUB Center for Structural Biology, Vlaams Instituut voor BiotechnologyBrusselsBelgium
- Structural Biology Brussels (SBB), Bioengineering Sciences DepartmentVrije Universiteit Brussel (VUB)BrusselsBelgium
| | - Attila Meszaros
- VIB‐VUB Center for Structural Biology, Vlaams Instituut voor BiotechnologyBrusselsBelgium
- Structural Biology Brussels (SBB), Bioengineering Sciences DepartmentVrije Universiteit Brussel (VUB)BrusselsBelgium
| | - Tamas Lazar
- VIB‐VUB Center for Structural Biology, Vlaams Instituut voor BiotechnologyBrusselsBelgium
- Structural Biology Brussels (SBB), Bioengineering Sciences DepartmentVrije Universiteit Brussel (VUB)BrusselsBelgium
| | - Peter Tompa
- VIB‐VUB Center for Structural Biology, Vlaams Instituut voor BiotechnologyBrusselsBelgium
- Structural Biology Brussels (SBB), Bioengineering Sciences DepartmentVrije Universiteit Brussel (VUB)BrusselsBelgium
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
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2
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Ito K, Takizawa T. Nuclear Architecture in the Nervous System: Development, Function, and Neurodevelopmental Diseases. Front Genet 2018; 9:308. [PMID: 30127803 PMCID: PMC6087739 DOI: 10.3389/fgene.2018.00308] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 07/19/2018] [Indexed: 12/22/2022] Open
Abstract
Decades of study have shown that epigenetic regulation plays an important role in neural development and function. Several layers of epigenetic mechanisms control functions of the eukaryotic cell nucleus, a well-organized subcellular organelle with distinct compartments: chromatin, its related architectural proteins, and nuclear bodies. As these components function together in the epigenetic regulation of cellular development and functions, they are collectively termed nuclear architecture. In the nervous system, dynamic rearrangement of nuclear architecture correlates with alteration of transcription programs. During maturation and upon depolarization, neurons undergo a reorganization of nuclear architecture that alters gene expression programs. As such changes allow for specialized functions, including learning and memory, nuclear architecture is distinct among cell types. Studying nuclear architecture of neurons may uncover cell-division-independent mechanisms of global and local changes to nuclear architecture. We herein review recent research concerning nuclear architecture in the nervous system and will discuss its importance to the development, maturation, function, and diseases of the nervous system.
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Affiliation(s)
- Kenji Ito
- Department of Pediatrics, Graduate School of Medicine, Gunma University, Maebashi, Japan.,Division of Stem Cell Pathology, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Takumi Takizawa
- Department of Pediatrics, Graduate School of Medicine, Gunma University, Maebashi, Japan
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3
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Li N, Han J, Tang J, Ying Y. IGFBP-7 inhibits the differentiation of oligodendrocyte precursor cells via regulation of Wnt/β-Catenin signaling. J Cell Biochem 2018; 119:4742-4750. [PMID: 29280192 DOI: 10.1002/jcb.26654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 12/20/2017] [Indexed: 11/09/2022]
Abstract
Oligodendrocytes (OLs) are glial cells that form myelin sheaths in the central nervous system. Myelin sheath plays important role in nervous system and loss of it in neurodegenerative diseases can lead to impairment of movement. Understanding the signals and factors that regulate OL differentiation can help to address novel strategies for improving myelin repair in neurodegenerative diseases. The aim of this study was to investigate the role of insulin-like growth factor-binding proteins 7 (IGFBP-7) in differentiating OL precursor cells (OPCs). It was found that oligodendrocyte precursors undergoing differentiation were accompanied by selective expression of IGFBP-7. In addition, knockdown of IGFBP-7 promoted differentiation of oligodendrocytes and increased formation of myelin in cultured cells. In contrast, excessive expression of IGFBP-7 inhibited differentiation of oligodendrocytes. Furthermore, overexpression of IGFBP-7 in oligodendrocyte precursor cells increased transcription of Wnt target genes and promoted β-Catenin nuclear translocation. These findings suggest that IGFBP-7 negatively regulates differentiation of oligodendrocyte precursor cells via regulation of Wnt/β-Catenin signaling.
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Affiliation(s)
- Nan Li
- Department of Intensive Care Unit, The First Hospital of Jilin University, Changchun, China
| | - Jinfeng Han
- Department of Intensive Care Unit, The First Hospital of Jilin University, Changchun, China
| | - Jing Tang
- Jinzhou Maternal and Children Healthy Care Hospital, Jinzhou, China
| | - Yanqin Ying
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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4
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Cao J, Wang PK, Tiwari V, Liang L, Lutz BM, Shieh KR, Zang WD, Kaufman AG, Bekker A, Gao XQ, Tao YX. Short-term pre- and post-operative stress prolongs incision-induced pain hypersensitivity without changing basal pain perception. Mol Pain 2015; 11:73. [PMID: 26626404 PMCID: PMC4667457 DOI: 10.1186/s12990-015-0077-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/12/2015] [Indexed: 02/27/2024] Open
Abstract
BACKGROUND Chronic stress has been reported to increase basal pain sensitivity and/or exacerbate existing persistent pain. However, most surgical patients have normal physiological and psychological health status such as normal pain perception before surgery although they do experience short-term stress during pre- and post-operative periods. Whether or not this short-term stress affects persistent postsurgical pain is unclear. RESULTS In this study, we showed that pre- or post-surgical exposure to immobilization 6 h daily for three consecutive days did not change basal responses to mechanical, thermal, or cold stimuli or peak levels of incision-induced hypersensitivity to these stimuli; however, immobilization did prolong the duration of incision-induced hypersensitivity in both male and female rats. These phenomena were also observed in post-surgical exposure to forced swimming 25 min daily for 3 consecutive days. Short-term stress induced by immobilization was demonstrated by an elevation in the level of serum corticosterone, an increase in swim immobility, and a decrease in sucrose consumption. Blocking this short-term stress via intrathecal administration of a selective glucocorticoid receptor antagonist, RU38486, or bilateral adrenalectomy significantly attenuated the prolongation of incision-induced hypersensitivity to mechanical, thermal, and cold stimuli. CONCLUSION Our results indicate that short-term stress during the pre- or post-operative period delays postoperative pain recovery although it does not affect basal pain perception. Prevention of short-term stress may facilitate patients' recovery from postoperative pain.
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Affiliation(s)
- Jing Cao
- Department of Anatomy, College of Basic Medicine, Zhengzhou University, Zhengzhou, 450001, Henan, China. .,Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA.
| | - Po-Kai Wang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA. .,Department of Anesthesiology, Buddhist Tzu Chi General Hospital, Institute of Medical Sciences, School of Medicine, Tzu Chi University, Hualien, Taiwan.
| | - Vinod Tiwari
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
| | - Lingli Liang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA.
| | - Brianna Marie Lutz
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA.
| | - Kun-Ruey Shieh
- Department of Physiology, School of Medicine, Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.
| | - Wei-Dong Zang
- Department of Anatomy, College of Basic Medicine, Zhengzhou University, Zhengzhou, 450001, Henan, China.
| | - Andrew G Kaufman
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA.
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA.
| | - Xiao-Qun Gao
- Department of Anatomy, College of Basic Medicine, Zhengzhou University, Zhengzhou, 450001, Henan, China.
| | - Yuan-Xiang Tao
- Department of Anatomy, College of Basic Medicine, Zhengzhou University, Zhengzhou, 450001, Henan, China. .,Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, 185 S. Orange Ave., MSB, F-548, Newark, NJ, 07103, USA.
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5
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Tan W, Pu Y, Shao Q, Fang X, Han D, Zhao M, Cao L. Insulin-like growth factor-binding protein 7 is up-regulated during EAE and inhibits the differentiation of oligodendrocyte precursor cells. Biochem Biophys Res Commun 2015; 460:639-44. [PMID: 25819415 DOI: 10.1016/j.bbrc.2015.03.082] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 03/14/2015] [Indexed: 11/27/2022]
Abstract
Oligodendrocyte precursor cells (OPCs) differentiation failure is one of the leading causes for remyelination defects in the demyelinating lesions of multiple sclerosis (MS). In this study, we explored the roles of insulin-like growth factor-binding proteins 7 (IGFBP-7) on OPCs differentiation during experimental autoimmune encephalomyelitis (EAE). We first investigated the expression pattern of IGFBP-7 by real-time PCR and immunofluorescence staining. It showed that IGFBP-7 was expressed in astrocytes (ACs), oligodendrocytes (OLs) and neurons both in vitro and in vivo. The mRNA and protein level of IGFBP-7 was also increased in the spinal cord from mice at the peak of EAE disease. Next we found that IGFBP-7 acted as a negatively regulator of the OPCs differentiation. Together, these data suggest that IGFBP-7 was up regulated during EAE and inhibit the transition from OPCs to mature OLs, implying its use as a potential therapeutic target for the treatment of inflammatory demyelinating diseases.
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Affiliation(s)
- Weixing Tan
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China
| | - Yingyan Pu
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China
| | - Qi Shao
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China
| | - Xue Fang
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China
| | - Dunxin Han
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China
| | - Ming Zhao
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China
| | - Li Cao
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of the Ministry of Education, Second Military Medical University, Shanghai 200433, China.
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6
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Zhao CF, Liu Y, Que HP, Yang SG, Liu ZQ, Weng XC, Hui HD, Liu SJ. SCIRR39 Promotes Differentiation of Oligodendrocyte Precursor Cells and Regulates Expression of Myelin-Associated Inhibitory Factors. J Mol Neurosci 2013; 50:533-41. [DOI: 10.1007/s12031-013-9983-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 02/15/2013] [Indexed: 12/22/2022]
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7
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Berndt A, Wilkinson KA, Henley JM. Regulation of Neuronal Protein Trafficking and Translocation by SUMOylation. Biomolecules 2012; 2:256-68. [PMID: 24970136 PMCID: PMC4030841 DOI: 10.3390/biom2020256] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Revised: 04/24/2012] [Accepted: 04/24/2012] [Indexed: 01/15/2023] Open
Abstract
Post-translational modifications of proteins are essential for cell function. Covalent modification by SUMO (small ubiquitin-like modifier) plays a role in multiple cell processes, including transcriptional regulation, DNA damage repair, protein localization and trafficking. Factors affecting protein localization and trafficking are particularly crucial in neurons because of their polarization, morphological complexity and functional specialization. SUMOylation has emerged as a major mediator of intranuclear and nucleo-cytoplasmic translocations of proteins involved in critical pathways such as circadian rhythm, apoptosis and protein degradation. In addition, SUMO-regulated re-localization of extranuclear proteins is required to sustain neuronal excitability and synaptic transmission. Thus, SUMOylation is a key arbiter of neuronal viability and function. Here, we provide an overview of recent advances in our understanding of regulation of neuronal protein localization and translocation by SUMO and highlight exciting areas of ongoing research.
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Affiliation(s)
- Anja Berndt
- School of Biochemistry, Medical Research Council Centre for Synaptic Plasticity, Medical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Kevin A Wilkinson
- School of Biochemistry, Medical Research Council Centre for Synaptic Plasticity, Medical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Jeremy M Henley
- School of Biochemistry, Medical Research Council Centre for Synaptic Plasticity, Medical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK.
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8
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Reorganization of Cajal bodies and nucleolar targeting of coilin in motor neurons of type I spinal muscular atrophy. Histochem Cell Biol 2012; 137:657-67. [DOI: 10.1007/s00418-012-0921-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2012] [Indexed: 12/21/2022]
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9
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Salomoni P, Betts-Henderson J. The role of PML in the nervous system. Mol Neurobiol 2010; 43:114-23. [PMID: 21161613 DOI: 10.1007/s12035-010-8156-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Accepted: 11/24/2010] [Indexed: 11/25/2022]
Abstract
The promyeloctic leukemia protein PML is a tumor suppressor that was originally identified due to its involvement in the (15;17) translocation of acute promyelocytic leukemia. While the majority of early research has focused upon the role of PML in the pathogenesis of leukemia, more recent evidence has identified important roles for PML in tissues outside the hemopoietic system, including the central nervous system (CNS). Here, we review recent literature on the role of PML in the CNS, with particular focus on the processes of neurodevelopment and neurodegeneration, and propose new lines of investigation.
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Affiliation(s)
- Paolo Salomoni
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6BT, UK.
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10
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Takizawa T, Meshorer E. Chromatin and nuclear architecture in the nervous system. Trends Neurosci 2008; 31:343-52. [PMID: 18538423 DOI: 10.1016/j.tins.2008.03.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 03/28/2008] [Accepted: 03/28/2008] [Indexed: 01/24/2023]
Abstract
Neurons are arguably the most varied cell type both morphologically and functionally. Their fate during differentiation and development and the activity of mature neurons are significantly determined and regulated by chromatin. The nucleus is compartmentalized and the arrangement of these compartments, termed the nuclear architecture, distinguishes one cell type from another and dictates many nuclear processes. Nuclear architecture determines the arrangement of chromosomes, the positioning of genes within chromosomes, the distribution of nuclear bodies and the interplay between these different factors. Importantly, chromatin regulation has been shown to be the basis for a variety of central nervous system processes including grooming and nursing, depression and stress, and drug abuse, among others. Here we review the regulation and function of nuclear architecture and chromatin structure in the context of the nervous system and discuss the potential use of histone deacetylase inhibitors as chromatin-directed therapy for nervous system disorders.
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Affiliation(s)
- Takumi Takizawa
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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11
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SUMO-1 transiently localizes to Cajal bodies in mammalian neurons. J Struct Biol 2008; 163:137-46. [PMID: 18571432 DOI: 10.1016/j.jsb.2008.04.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 04/21/2008] [Accepted: 04/25/2008] [Indexed: 11/21/2022]
Abstract
Cajal bodies (CBs) are nuclear organelles involved in the maturation of small nuclear ribonucleoproteins required for the processing of pre-mRNAs. They concentrate coilin, splicing factors and the survival of motor neuron protein (SMN). By using immunocytochemistry and transfection experiments with GFP-SUMO-1, DsRed1-Ubc9, GFP-coilin and GFP-SMN constructs we demonstrate the presence of SUMO-1 and the SUMO conjugating enzyme (Ubc9) in a subset of CBs in undifferentiated neuron-like UR61 cells. Furthermore, SUMO-1 is transiently localized into neuronal CBs from adult nervous tissue in response to osmotic stress or inhibition of methyltransferase activity. SUMO-1-positive CBs contain coilin, SMN and small nuclear ribonucleoproteins, suggesting that they are functional CBs involved in pre-mRNA processing. Since coilin and SMN have several putative motifs of SUMO-1 modification, we suggest that the sumoylation of coilin and/or SMN might play a role in the molecular reorganization of CBs during the neuronal differentiation or stress-response.
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12
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Everett RD, Murray J, Orr A, Preston CM. Herpes simplex virus type 1 genomes are associated with ND10 nuclear substructures in quiescently infected human fibroblasts. J Virol 2007; 81:10991-1004. [PMID: 17670833 PMCID: PMC2045565 DOI: 10.1128/jvi.00705-07] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) genomes become associated with structures related to cellular nuclear substructures known as ND10 or promyelocytic leukemia nuclear bodies during the early stages of lytic infection. This paper describes the relationship between HSV-1 genomes and ND10 in human fibroblasts that maintain the viral genomes in a quiescent state. We report that quiescent HSV-1 genomes detected by fluorescence in situ hybridization (FISH) are associated with enlarged ND10-like structures, frequently such that the FISH-defined viral foci are apparently enveloped within a sphere of PML and other ND10 proteins. The number of FISH viral foci in each quiescently infected cell is concordant with the input multiplicity of infection, with each structure containing no more than a small number of viral genomes. A proportion of the enlarged ND10-like foci in quiescently infected cells contain accumulations of the heterochromatin protein HP1 but not other common markers of heterochromatin such as histone H3 di- or trimethylated on lysine residue 9. Many of the virally induced enlarged ND10-like structures also contain concentrations of conjugated ubiquitin. Quiescent infections can be established in cells that are highly depleted for PML. However, during the initial stages of establishment of a quiescent infection in such cells, other ND10 proteins (Sp100, hDaxx, and ATRX) are recruited into virally induced foci that are likely to be associated with HSV-1 genomes. These observations illustrate that the intimate connections between HSV-1 genomes and ND10 that occur during lytic infection also extend to quiescent infections.
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Affiliation(s)
- Roger D Everett
- MRC Virology Unit, Church Street, Glasgow G11 5JR, Scotland, United Kingdom.
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13
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Navascués J, Bengoechea R, Tapia O, Vaqué JP, Lafarga M, Berciano MT. Characterization of a new SUMO-1 nuclear body (SNB) enriched in pCREB, CBP, c-Jun in neuron-like UR61 cells. Chromosoma 2007; 116:441-51. [PMID: 17549507 DOI: 10.1007/s00412-007-0107-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 03/22/2007] [Accepted: 03/30/2007] [Indexed: 12/29/2022]
Abstract
The neuron-like UR61 cell is a stable PC12 subline that contains a mouse N-ras oncogene. Dexamethasone (Dex) treatment induces a neuron-like differentiation, which is associated with neuritogenesis and nuclear expression of the glucocorticoid receptor and c-Jun. In differentiated UR61 cells, small ubiquitin-like modifiers 1 (SUMO-1) is concentrated in a new category of SUMO-1 nuclear bodies (SNBs) distinct from promyelocytic leukemia (PML) bodies by their large size and absence of PML protein. SNBs are 1 to 3 mum in diameter and exhibit a fine granular texture by electron microscopy. They are free of splicing factors and transcription foci and show spatial associations with Cajal bodies. In addition to SUMO-1 and the E2-conjugating enzyme Ubc9, which is essential for sumoylation, SNBs concentrate the transcriptional regulators CBP, CREB, and c-Jun. Moreover, transfection experiments demonstrate that SNBs accumulate the active conjugating form of SUMO-1 but not the conjugation defective variant of SUMO-1, supporting that SNBs are sites of sumoylation. Our results suggest that SNBs play a role in the control of the nucleoplasmic concentration of transcription regulators involved in neuroprotection and survival of the UR61 cells.
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Affiliation(s)
- Joaquín Navascués
- Division of Gene Regulation and Expression, Wellcome Trust Biocentre, University of Dundee, DD1 5EH, Dundee, UK
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14
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Woulfe JM, Prichett-Pejic W, Rippstein P, Munoz DG. Promyelocytic leukaemia-immunoreactive neuronal intranuclear rodlets in the human brain. Neuropathol Appl Neurobiol 2007; 33:56-66. [PMID: 17239008 DOI: 10.1111/j.1365-2990.2006.00789.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In a previous study, we demonstrated immunoreactivity of a subset of neuronal intranuclear rodlets (INRs) in the human substantia nigra for promyelocytic leukaemia (PML) protein, the signature protein of PML bodies. In the present study, we extend these observations and describe the ultrastructural features, immunohistochemical staining characteristics, and topographical pattern of distribution of PML-immunoreactive intranuclear rodlets (PML-INRs). Consistent with a purported role for PML bodies in nuclear proteolysis and/or transcriptional regulation, PML-INRs are immunoreactive for components of the ubiquitin-proteasome system, the transcriptional regulator CREB-binding protein, acetylated histone H4, and the eukaryotic translation initiation factor eIF4E. Immunoelectron microscopy reveals that they all possess a filamentous core and, in some, this is surrounded by a granular shell. We further demonstrate that a proportion of INRs in extranigral sites also show partial immunoreactivity for PML. These observations indicate an intimate association between two neuronal nuclear bodies, PML bodies and INRs. Because both of these structures have been implicated in neurodegenerative disease, PML-INRs may provide a tool with which to study changes in nuclear substructure in disease.
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Affiliation(s)
- J M Woulfe
- Cancer Research Program, The Ottawa Health Research Institute, Ottawa, Ontario, Canada.
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15
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Berciano MT, Novell M, Villagra NT, Casafont I, Bengoechea R, Val-Bernal JF, Lafarga M. Cajal body number and nucleolar size correlate with the cell body mass in human sensory ganglia neurons. J Struct Biol 2006; 158:410-20. [PMID: 17275332 DOI: 10.1016/j.jsb.2006.12.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 12/21/2006] [Accepted: 12/21/2006] [Indexed: 12/29/2022]
Abstract
This paper studies the cell size-dependent organization of the nucleolus and Cajal bodies (CBs) in dissociated human dorsal root ganglia (DRG) neurons from autopsy tissue samples of patients without neurological disease. The quantitative analysis of nucleoli with an anti-fibrillarin antibody showed that all neurons have only one nucleolus. However, the nucleolar volume and the number of fibrillar centers per nucleolus significantly increase as a function of cell body size. Immunostaining for coilin demonstrated the presence of numerous CBs in DRG neurons (up to 20 in large size neurons). The number of CBs per neuron correlated positively with the cell body volume. Light and electron microscopy immunocytochemical analysis revealed the concentration of coilin, snRNPs, SMN and fibrillarin in CBs of DRG neurons. CBs were frequently associated with the nucleolus, active chromatin domains and PML bodies, but not with telomeres. Our results support the view that the nucleolar volume and number of both fibrillar centers and CBs depend on the cell body mass, a parameter closely related to transcriptional and synaptic activity in mammalian neurons. Moreover, the unusual large number of CBs could facilitate the transfer of RNA processing components from CBs to nucleolar and nucleoplasmic sites of RNA processing.
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Affiliation(s)
- Maria T Berciano
- Department of Anatomy and Cell Biology, and Biomedicine Unit (CSIC), University of Cantabria, Santander, Spain
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16
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Valero J, Berciano MT, Weruaga E, Lafarga M, Alonso JR. Pre-neurodegeneration of mitral cells in the pcd mutant mouse is associated with DNA damage, transcriptional repression, and reorganization of nuclear speckles and Cajal bodies. Mol Cell Neurosci 2006; 33:283-95. [PMID: 16978877 DOI: 10.1016/j.mcn.2006.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Revised: 07/04/2006] [Accepted: 08/01/2006] [Indexed: 01/01/2023] Open
Abstract
DNA damage and impairment of its repair underlie several neurodegenerative diseases. The Purkinje cell degeneration (pcd) mutation causes the loss of Nna1 expression and is associated with a selective and progressive degeneration of specific neuronal populations, including mitral cells in the olfactory bulb. Using an in situ transcription assay, molecular markers for both nuclear compartments and components of the DNA damage/repair pathway, and ultrastructural analysis, here we demonstrate that the pcd mutation induces the formation of DNA damage/repair foci in mitral cells. Furthermore, this effect is associated with transcriptional inhibition, heterochromatinization, nucleolar segregation and the reorganization of nuclear speckles of splicing factors and Cajal bodies. The most significant cytoplasmic alteration observed was a partial replacement of rough endoplasmic reticulum cisternae by a larger amount of free ribosomes, while other organelles were structurally preserved. The tools employed in this work may be of use for the early detection of predegenerative processes in neurodegenerative disorders and for validating rescue strategies.
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Affiliation(s)
- Jorge Valero
- Laboratorio de Plasticidad Neuronal y Neurorreparación, Instituto de Neurociencias de Castilla y León, Universidad de Salamanca. Avd. Alfonso X el Sabio s/n, E-37007 Salamanca, Spain
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17
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Villagra NT, Navascues J, Casafont I, Val-Bernal JF, Lafarga M, Berciano MT. The PML-nuclear inclusion of human supraoptic neurons: a new compartment with SUMO-1- and ubiquitin-proteasome-associated domains. Neurobiol Dis 2005; 21:181-93. [PMID: 16125395 DOI: 10.1016/j.nbd.2005.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 06/30/2005] [Accepted: 07/06/2005] [Indexed: 12/12/2022] Open
Abstract
It is well known that the cell nucleus is organized in structural and functional compartments involved in transcription, RNA processing and protein modifications such as conjugation with SUMO-1 and proteolysis. Promyelocytic leukaemia (PML) bodies are dynamic nuclear structures that concentrate PML protein, SUMO-1 and several sumoylated and non-sumoylated protein regulators of nuclear functions. PML bodies and their associated CBP has been involved in neuronal survival. By light and electron microscopy immunocytochemistry and in situ hybridization we reported the presence, in non-pathological conditions, of a large PML-nuclear inclusion (PML-NI) in human supraoptic neurons. This inclusion appears as a single nuclear structure composed of a capsule enriched in PML, SUMO-1 and CBP proteins and a central lattice of filaments immunoreactive for class III beta-tubulin, ubiquitinated proteins and proteasomes. Furthermore, the PML-NI concentrates the SUMO-conjugating enzyme E2 (UBC9). The PML-NI may be considered a nuclear factory involved in sumoylation and proteolysis via ubiquitin-proteasome system, two nuclear pathways engaged in the control of the nucleoplasmic concentration of active transcriptional regulators. Interestingly, the structural and molecular organization of the PML-NI is related to the Marinesco bodies, age-associated ubiquitinated intranuclear inclusions, and to the intranuclear rodlets enriched in class III beta-tubulin, which are nuclear structures markedly decreased in Alzheimer's disease.
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Affiliation(s)
- Nuria T Villagra
- Department of Anatomic Pathology, Marqués de Valdecilla University Hospital, University of Cantabria, Santander, Spain
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18
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Mi S, Miller RH, Lee X, Scott ML, Shulag-Morskaya S, Shao Z, Chang J, Thill G, Levesque M, Zhang M, Hession C, Sah D, Trapp B, He Z, Jung V, McCoy JM, Pepinsky RB. LINGO-1 negatively regulates myelination by oligodendrocytes. Nat Neurosci 2005; 8:745-51. [PMID: 15895088 DOI: 10.1038/nn1460] [Citation(s) in RCA: 470] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Accepted: 04/19/2005] [Indexed: 11/09/2022]
Abstract
The control of myelination by oligodendrocytes in the CNS is poorly understood. Here we show that LINGO-1 is an important negative regulator of this critical process. LINGO-1 is expressed in oligodendrocytes. Attenuation of its function by dominant-negative LINGO-1, LINGO-1 RNA-mediated interference (RNAi) or soluble human LINGO-1 (LINGO-1-Fc) leads to differentiation and increased myelination competence. Attenuation of LINGO-1 results in downregulation of RhoA activity, which has been implicated in oligodendrocyte differentiation. Conversely, overexpression of LINGO-1 leads to activation of RhoA and inhibition of oligodendrocyte differentiation and myelination. Treatment of oligodendrocyte and neuron cocultures with LINGO-1-Fc resulted in highly developed myelinated axons that have internodes and well-defined nodes of Ranvier. The contribution of LINGO-1 to myelination was verified in vivo through the analysis of LINGO-1 knockout mice. The ability to recapitulate CNS myelination in vitro using LINGO-1 antagonists and the in vivo effects seen in the LINGO-1 knockout indicate that LINGO-1 signaling may be critical for CNS myelination.
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MESH Headings
- Animals
- Cell Differentiation/drug effects
- Cell Differentiation/genetics
- Cells, Cultured
- Central Nervous System/embryology
- Central Nervous System/growth & development
- Central Nervous System/metabolism
- Coculture Techniques
- Down-Regulation/drug effects
- Down-Regulation/genetics
- Gene Expression Regulation, Developmental/drug effects
- Gene Expression Regulation, Developmental/genetics
- Humans
- Membrane Proteins
- Mice
- Mice, Knockout
- Microscopy, Electron, Transmission
- Myelin Sheath/genetics
- Myelin Sheath/metabolism
- Myelin Sheath/ultrastructure
- Myelin-Associated Glycoprotein/antagonists & inhibitors
- Myelin-Associated Glycoprotein/genetics
- Myelin-Associated Glycoprotein/metabolism
- Nerve Fibers, Myelinated/drug effects
- Nerve Fibers, Myelinated/metabolism
- Nerve Fibers, Myelinated/ultrastructure
- Nerve Tissue Proteins
- Oligodendroglia/drug effects
- Oligodendroglia/metabolism
- Oligodendroglia/ultrastructure
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-fyn
- RNA Interference/drug effects
- RNA Interference/physiology
- Ranvier's Nodes/genetics
- Ranvier's Nodes/metabolism
- Ranvier's Nodes/ultrastructure
- Rats
- Rats, Long-Evans
- Receptors, Cell Surface/antagonists & inhibitors
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- rhoA GTP-Binding Protein/metabolism
- src-Family Kinases/genetics
- src-Family Kinases/metabolism
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Affiliation(s)
- Sha Mi
- Department of Discovery Biology, Biogen Idec, Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142, USA.
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19
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Woulfe J, Gray D, Prichett-Pejic W, Munoz DG, Chretien M. Intranuclear Rodlets in the Substantia Nigra: Interactions with Marinesco Bodies, Ubiquitin, and Promyelocytic Leukemia Protein. J Neuropathol Exp Neurol 2004; 63:1200-7. [PMID: 15581187 DOI: 10.1093/jnen/63.11.1200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
There is growing appreciation that the nucleus is organized into an array of discrete structural domains, each subserving a specific function. These functional nuclear bodies are to be distinguished from pathological intranuclear inclusions which have been described in a variety of neurodegenerative diseases. Marinesco bodies (MBs) are eosinophilic ubiquitinated intranuclear inclusions found in pigmented neurons of the human substantia nigra and locus coeruleus. Traditionally considered non-pathological entities, more recent studies have indicated that MBs are associated with the age-associated degenerative changes in the substantia nigra and striatal loss of dopaminergic terminals. In the present morphological study of the human substantia nigra, we demonstrate colocalization, contiguity, and focally shared immunoreactivity between MBs and neuronal intranuclear rodlets (INRs). The latter nuclear structures of uncertain function are markedly decreased in the cortex of Alzheimer's disease, but not dementia with Lewy bodies. In addition, we demonstrate an interaction between INRs and promyelocytic leukemia (PML) protein, the signature protein of PML nuclear bodies. These results suggest that structures which subserve the functional compartmentalization of the neuronal nucleus may be relevant to elucidating cellular mechanisms of age-related motor dysfunction.
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Affiliation(s)
- John Woulfe
- The Ottawa Hospital, Ottawa, Ontario, Canada.
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