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Ozarkar SS, Patel RKR, Vulli T, Smith AL, Shen MD, Burette AC, Philpot BD, Styner MA, Hazlett HC. Comparative profiling of white matter development in the human and mouse brain reveals volumetric deficits and delayed myelination in Angelman syndrome. RESEARCH SQUARE 2024:rs.3.rs-4681861. [PMID: 39149488 PMCID: PMC11326408 DOI: 10.21203/rs.3.rs-4681861/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Background Angelman syndrome (AS), a severe neurodevelopmental disorder resulting from the loss of the maternal UBE3A gene, is marked by changes in the brain's white matter (WM). The extent of WM abnormalities seems to correlate with the severity of clinical symptoms, but these deficits are still not well characterized or understood. This study provides the first large-scale measurement of WM volume reduction in children with AS. Furthermore, we probed the underlying neuropathology by examining the progression of myelination in an AS mouse model. Methods We conducted magnetic resonance imaging (MRI) on children with AS (n=32) and neurotypical controls (n=99) aged 0.5-12 years. In parallel, we examined myelination in postnatal Ube3a maternal-null mice (Ube3a m-/p+; AS model), Ube3a paternal-null mice (Ube3a m+/p-), and wildtype controls (Ube3a m+/p+) using immunohistochemistry, Western blotting, and electron microscopy. Results Our data revealed that AS individuals exhibit significant reductions in brain volume by ~1 year of age, with WM reduced by 26% and gray matter by 21% by 6-12 years of age-approximately twice the reductions observed in the adult AS mouse model. In our AS mouse model, we saw a global delay in the onset of myelination, which normalized within days (likely corresponding to months or years in human development). This myelination delay is caused by the loss of UBE3A in neurons rather than UBE3A haploinsufficiency in oligodendrocytes. Interestingly, ultrastructural analyses did not reveal any abnormalities in myelinated or unmyelinated axons. Limitations It is difficult to extrapolate the timing and duration of the myelination delay observed in AS model mice to individuals with AS. Conclusions This study reveals WM deficits as a hallmark in children with AS, demonstrating for the first time that these deficits are already apparent at 1 year of age. Parallel studies in a mouse model of AS show that these deficits may be associated with delayed onset of myelination due to the loss of neuronal (but not glial) UBE3A. These findings emphasize the potential of WM as both a therapeutic target for interventions and a valuable biomarker for tracking the progression of AS and the effectiveness of potential treatments.
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Affiliation(s)
- Siddhi S Ozarkar
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Ridthi K-R Patel
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Tasmai Vulli
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Audrey L Smith
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mark D Shen
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Alain C Burette
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Benjamin D Philpot
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Martin A Styner
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel
| | - Heather C Hazlett
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC
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2
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Quintela-López T, Ortiz-Sanz C, Serrano-Regal MP, Gaminde-Blasco A, Valero J, Baleriola J, Sánchez-Gómez MV, Matute C, Alberdi E. Aβ oligomers promote oligodendrocyte differentiation and maturation via integrin β1 and Fyn kinase signaling. Cell Death Dis 2019; 10:445. [PMID: 31171765 PMCID: PMC6554322 DOI: 10.1038/s41419-019-1636-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/17/2019] [Accepted: 05/08/2019] [Indexed: 12/13/2022]
Abstract
Alzheimer´s disease (AD) is characterized by a progressive cognitive decline that correlates with the levels of amyloid β-peptide (Aβ) oligomers. Strong evidences connect changes of oligodendrocyte function with the onset of neurodegeneration in AD. However, the mechanisms controlling oligodendrocyte responses to Aβ are still elusive. Here, we tested the role of Aβ in oligodendrocyte differentiation, maturation, and survival in isolated oligodendrocytes and in organotypic cerebellar slices. We found that Aβ peptides specifically induced local translation of 18.5-kDa myelin basic protein (MBP) isoform in distal cell processes concomitant with an increase of process complexity of MBP-expressing oligodendrocytes. Aβ oligomers required integrin β1 receptor, Src-family kinase Fyn and Ca2+/CaMKII as effectors to modulate MBP protein expression. The pharmacological inhibition of Fyn kinase also attenuated oligodendrocyte differentiation and survival induced by Aβ oligomers. Similarly, using ex vivo organotypic cerebellar slices Aβ promoted MBP upregulation through Fyn kinase, and modulated oligodendrocyte population dynamics by inducing cell proliferation and differentiation. Importantly, application of Aβ to cerebellar organotypic slices enhanced remyelination and oligodendrocyte lineage recovery in lysolecithin (LPC)-induced demyelination. These data reveal an important role of Aβ in oligodendrocyte lineage function and maturation, which may be relevant to AD pathogenesis.
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Affiliation(s)
- Tania Quintela-López
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Carolina Ortiz-Sanz
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Mari Paz Serrano-Regal
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Adhara Gaminde-Blasco
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Jimena Baleriola
- Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain.,Department of Cell Biology and Histology, UPV/EHU, Leioa, 48940, Spain
| | - Maria Victoria Sánchez-Gómez
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Carlos Matute
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain. .,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain. .,CIBERNED, Leioa, 48940, Spain.
| | - Elena Alberdi
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain. .,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain. .,CIBERNED, Leioa, 48940, Spain.
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3
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Chaudhuri R, Khanna K, Koundinya D, Pattnaik B, Vatsa D, Agrawal A, Ghosh B. Novel nuclear translocation of inositol polyphosphate 4-phosphatase is associated with cell cycle, proliferation and survival. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2018; 1865:S0167-4889(18)30188-5. [PMID: 30071275 DOI: 10.1016/j.bbamcr.2018.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
Inositol polyphosphate 4 phosphatase type I enzyme (INPP4A) has a well-documented function in the cytoplasm where it terminates the phosphatidylinositol 3-kinase (PI 3-K) pathway by acting as a negative regulator. In this study, we demonstrate for the first time that INPP4A shuttles between the cytoplasm and the nucleus. Nuclear INPP4A is enzymatically active and in dynamic equilibrium between the nucleus and cytoplasm depending on the cell cycle stage, with highest amounts detected in the nucleus during the G0/G1 phase. Moreover, nuclear INPP4A is found to have direct proliferation suppressive activity. Cells constitutively overexpressing nuclear INPP4A exhibit massive apoptosis. In human tissues as well as cell lines, lower nuclear localization of INPP4A correlate with cancerous growth. Together, our findings suggest that nuclear compartmentalization of INPP4A may be a mechanism to regulate cell cycle progression, proliferation and apoptosis. Our results imply a role for nuclear-localized INPP4A in tumor suppression in humans.
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Affiliation(s)
- Rituparna Chaudhuri
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India.; Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Kritika Khanna
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India.; Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - D Koundinya
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India.; Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Bijay Pattnaik
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India.; Department of Pulmonary Medicine and Sleep Disorders, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Damini Vatsa
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India
| | - Anurag Agrawal
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India.; Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Balaram Ghosh
- Molecular Immunogenetics Laboratory and Centre of Excellence for Translational Research in Asthma & Lung disease, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007,India.; Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India..
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4
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Torvund-Jensen J, Steengaard J, Askebjerg LB, Kjaer-Sorensen K, Laursen LS. The 3'UTRs of Myelin Basic Protein mRNAs Regulate Transport, Local Translation and Sensitivity to Neuronal Activity in Zebrafish. Front Mol Neurosci 2018; 11:185. [PMID: 29946237 PMCID: PMC6006989 DOI: 10.3389/fnmol.2018.00185] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/14/2018] [Indexed: 02/04/2023] Open
Abstract
Formation of functional myelin sheaths within the central nervous system depends on expression of myelin basic protein (MBP). Following process extension and wrapping around axonal segments, this highly basic protein is required for compaction of the multi-layered membrane sheath produced by oligodendrocytes. MBP is hypothesized to be targeted to the membrane sheath by mRNA transport and local translation, which ensures that its expression is temporally and spatially restricted. The mechanistic details of how this might be regulated are still largely unknown, in particular because a model system that allows this process to be studied in vivo is lacking. We here show that the expression of the zebrafish MBP orthologs, mbpa and mbpb, is developmentally regulated, and that expression of specific mbpa isoforms is restricted to the peripheral nervous system. By analysis of transgenic zebrafish, which express a fluorescent reporter protein specifically in myelinating oligodendrocytes, we demonstrate that both mbpa and mbpb include a 3’UTR sequence, by which mRNA transport and translation is regulated in vivo. Further functional analysis suggests that: (1) the 3’UTRs delay the onset of protein expression; and that (2) several regulatory elements contribute to targeting of the mbp mRNA to the myelin sheath. Finally, we show that a pharmacological compound known to enhance neuronal activity stimulates the translation of Mbp in zebrafish in a 3’UTR-dependent manner. A similar effect was obtained following stimulation with a TrkB receptor agonist, and cell-based assays further confirmed that the receptor ligand, BDNF, in combination with other signals reversed the inhibitory effect of the 3’UTR on translation.
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Affiliation(s)
- Julie Torvund-Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jes Steengaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | | | - Lisbeth S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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5
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Hoch-Kraft P, White R, Tenzer S, Krämer-Albers EM, Trotter J, Gonsior C. Dual role of the RNA helicase DDX5 in post-transcriptional regulation of Myelin Basic Protein in oligodendrocytes. J Cell Sci 2018; 131:jcs.204750. [DOI: 10.1242/jcs.204750] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 03/28/2018] [Indexed: 01/11/2023] Open
Abstract
In the central nervous system, oligodendroglial expression of Myelin Basic Protein (MBP) is crucial for the assembly and structure of the myelin sheath. MBP synthesis is tightly regulated in space and time, particularly on the post-transcriptional level. We have identified the DEAD-box RNA helicase DDX5 (alias p68) in a complex with Mbp mRNA in oligodendroglial cells. Expression of DDX5 is highest in progenitor cells and immature oligodendrocytes, where it localizes to heterogeneous populations of cytoplasmic ribonucleoprotein (RNP) complexes associated with Mbp mRNA in the cell body and processes. Manipulation of DDX5 protein amounts inversely affects levels of MBP protein. We present evidence that DDX5 is involved in post-transcriptional regulation of MBP protein synthesis, with implications for oligodendroglial development. In addition, DDX5 knockdown results in an increased abundance of MBP exon 2-positive isoforms in immature oligodendrocytes, most likely by regulating alternative splicing of Mbp. Our findings contribute to the understanding of the complex nature of MBP post-transcriptional control in immature oligodendrocytes where DDX5 appears to affect the abundance of MBP proteins via distinct but converging mechanisms.
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Affiliation(s)
- Peter Hoch-Kraft
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
| | - Robin White
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg-University, Duesbergweg 6, 55128 Mainz, Germany
| | - Stefan Tenzer
- Institute for Immunology, University Medical Center Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Eva-Maria Krämer-Albers
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
| | - Jacqueline Trotter
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
| | - Constantin Gonsior
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
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6
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Mueller M, Oppliger B, Joerger-Messerli M, Reinhart U, Barnea E, Paidas M, Kramer BW, Surbek DV, Schoeberlein A. Wharton's Jelly Mesenchymal Stem Cells Protect the Immature Brain in Rats and Modulate Cell Fate. Stem Cells Dev 2016; 26:239-248. [PMID: 27842457 DOI: 10.1089/scd.2016.0108] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The development of a mammalian brain is a complex and long-lasting process. Not surprisingly, preterm birth is the leading cause of death in newborns and children. Advances in perinatal care reduced mortality, but morbidity still represents a major burden. New therapeutic approaches are thus desperately needed. Given that mesenchymal stem/stromal cells (MSCs) emerged as a promising candidate for cell therapy, we transplanted MSCs derived from the Wharton's Jelly (WJ-MSCs) to reduce the burden of immature brain injury in a murine animal model. WJ-MSCs transplantation resulted in protective activity characterized by reduced myelin loss and astroglial activation. WJ-MSCs improved locomotor behavior as well. To address the underlying mechanisms, we tested the key regulators of responses to DNA-damaging agents, such as cyclic AMP-dependent protein kinase/calcium-dependent protein kinase (PKA/PKC), cyclin-dependent kinase (CDK), ataxia-telangiectasia-mutated/ATM- and Rad3-related (ATM/ATR) substrates, protein kinase B (Akt), and 14-3-3 binding protein partners. We characterized WJ-MSCs using a specific profiler polymerase chain reaction array. We provide evidence that WJ-MSCs target pivotal regulators of the cell fate such as CDK/14-3-3/Akt signaling. We identified leukemia inhibitory factor as a potential candidate of WJ-MSCs' induced modifications as well. We hypothesize that WJ-MSCs may exert adaptive responses depending on the type of injury they are facing, making them prominent candidates for cell therapy in perinatal injuries.
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Affiliation(s)
- Martin Mueller
- 1 Department of Clinical Research, University of Bern , Bern, Switzerland .,2 Department of Obstetrics and Gynecology, University of Bern , Bern, Switzerland .,3 Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine , New Haven, Connecticut
| | - Byron Oppliger
- 1 Department of Clinical Research, University of Bern , Bern, Switzerland .,2 Department of Obstetrics and Gynecology, University of Bern , Bern, Switzerland
| | - Marianne Joerger-Messerli
- 1 Department of Clinical Research, University of Bern , Bern, Switzerland .,2 Department of Obstetrics and Gynecology, University of Bern , Bern, Switzerland
| | - Ursula Reinhart
- 1 Department of Clinical Research, University of Bern , Bern, Switzerland .,2 Department of Obstetrics and Gynecology, University of Bern , Bern, Switzerland
| | - Eytan Barnea
- 4 Society for the Investigation of Early Pregnancy and BioIncept LLC , Cherry Hill, New Jersey
| | - Michael Paidas
- 3 Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine , New Haven, Connecticut
| | - Boris W Kramer
- 5 Department of Pediatrics, Maastricht University Medical Center (MUMC) , Maastricht, the Netherlands .,6 Division Neuroscience, Department of Neuropsychology, School of Mental Health and Neuroscience (MHeNS), Maastricht University , Maastricht, the Netherlands
| | - Daniel V Surbek
- 1 Department of Clinical Research, University of Bern , Bern, Switzerland .,2 Department of Obstetrics and Gynecology, University of Bern , Bern, Switzerland
| | - Andreina Schoeberlein
- 1 Department of Clinical Research, University of Bern , Bern, Switzerland .,2 Department of Obstetrics and Gynecology, University of Bern , Bern, Switzerland
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Ozgen H, Baron W, Hoekstra D, Kahya N. Oligodendroglial membrane dynamics in relation to myelin biogenesis. Cell Mol Life Sci 2016; 73:3291-310. [PMID: 27141942 PMCID: PMC4967101 DOI: 10.1007/s00018-016-2228-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/14/2016] [Indexed: 12/12/2022]
Abstract
In the central nervous system, oligodendrocytes synthesize a specialized membrane, the myelin membrane, which enwraps the axons in a multilamellar fashion to provide fast action potential conduction and to ensure axonal integrity. When compared to other membranes, the composition of myelin membranes is unique with its relatively high lipid to protein ratio. Their biogenesis is quite complex and requires a tight regulation of sequential events, which are deregulated in demyelinating diseases such as multiple sclerosis. To devise strategies for remedying such defects, it is crucial to understand molecular mechanisms that underlie myelin assembly and dynamics, including the ability of specific lipids to organize proteins and/or mediate protein-protein interactions in healthy versus diseased myelin membranes. The tight regulation of myelin membrane formation has been widely investigated with classical biochemical and cell biological techniques, both in vitro and in vivo. However, our knowledge about myelin membrane dynamics, such as membrane fluidity in conjunction with the movement/diffusion of proteins and lipids in the membrane and the specificity and role of distinct lipid-protein and protein-protein interactions, is limited. Here, we provide an overview of recent findings about the myelin structure in terms of myelin lipids, proteins and membrane microdomains. To give insight into myelin membrane dynamics, we will particularly highlight the application of model membranes and advanced biophysical techniques, i.e., approaches which clearly provide an added value to insight obtained by classical biochemical techniques.
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Affiliation(s)
- Hande Ozgen
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Wia Baron
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
| | - Dick Hoekstra
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Nicoletta Kahya
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
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8
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MyelStones: the executive roles of myelin basic protein in myelin assembly and destabilization in multiple sclerosis. Biochem J 2015; 472:17-32. [DOI: 10.1042/bj20150710] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The classic isoforms of myelin basic protein (MBP, 14–21.5 kDa) are essential to formation of the multilamellar myelin sheath of the mammalian central nervous system (CNS). The predominant 18.5-kDa isoform links together the cytosolic surfaces of oligodendrocytes, but additionally participates in cytoskeletal turnover and membrane extension, Fyn-mediated signalling pathways, sequestration of phosphoinositides and maintenance of calcium homoeostasis. All MBP isoforms are intrinsically disordered proteins (IDPs) that interact via molecular recognition fragments (MoRFs), which thereby undergo local disorder-to-order transitions. Their conformations and associations are modulated by environment and by a dynamic barcode of post-translational modifications, particularly phosphorylation by mitogen-activated and other protein kinases and deimination [a hallmark of demyelination in multiple sclerosis (MS)]. The MBPs are thus to myelin what basic histones are to chromatin. Originally thought to be merely structural proteins forming an inert spool, histones are now known to be dynamic entities involved in epigenetic regulation and diseases such as cancer. Analogously, the MBPs are not mere adhesives of compact myelin, but active participants in oligodendrocyte proliferation and in membrane process extension and stabilization during myelinogenesis. A central segment of these proteins is pivotal in membrane-anchoring and SH3 domain (Src homology 3) interaction. We discuss in the present review advances in our understanding of conformational conversions of this classic basic protein upon membrane association, including new thermodynamic analyses of transitions into different structural ensembles and how a shift in the pattern of its post-translational modifications is associated with the pathogenesis and potentially onset of demyelination in MS.
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9
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Prindull G. Potential Gene Interactions in the Cell Cycles of Gametes, Zygotes, Embryonic Stem Cells and the Development of Cancer. Front Oncol 2015; 5:200. [PMID: 26442212 PMCID: PMC4585297 DOI: 10.3389/fonc.2015.00200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 08/31/2015] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES This review is to explore whether potential gene interactions in the cell cycles of gametes, zygotes, and embryonic stem (ES) cells are associated with the development of cancer. METHODS MEDPILOT at the Central Library of the University of Cologne, Germany (Zentralbibliothek Köln) that covers 5,800 international medical journals and 4,300 E-journals was used to collect data. The initial searches were done in December 2012 and additional searches in October 2013-May 2015. The search terms included "cancer development," "gene interaction," and "ES cells," and the time period was between 1998 and 2015. A total of 147 articles in English language only were included in this review. RESULTS Transgenerational gene translation is implemented in the zygote through interactions of epigenetic isoforms of transcription factors (TFs) from parental gametes, predominantly during the first two zygote cleavages. Pluripotent transcription factors may provide interacting links with mutated genes during zygote-to-ES cell switches. Translation of post-transcriptional carcinogenic genes is implemented by abnormally spliced, tumor-specific isoforms of gene-encoded mRNA/non-coding RNA variants of TFs employing de novo gene synthesis and neofunctionalization. Post-translationally, mutated genes are preserved in pre-neoplastic ES cell subpopulations that can give rise to overt cancer stem cells. Thus, TFs operate as cell/disease-specific epigenetic messengers triggering clinical expression of neoplasms. CONCLUSION Potential gene interactions in the cell cycle of gametes, zygotes, and ES cells may play some roles in the development of cancer.
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Affiliation(s)
- Gregor Prindull
- Medical Faculty, University of Göttingen , Göttingen , Germany
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10
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Intracellular Protein Shuttling: A Mechanism Relevant for Myelin Repair in Multiple Sclerosis? Int J Mol Sci 2015; 16:15057-85. [PMID: 26151843 PMCID: PMC4519887 DOI: 10.3390/ijms160715057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 06/23/2015] [Accepted: 06/25/2015] [Indexed: 12/15/2022] Open
Abstract
A prominent feature of demyelinating diseases such as multiple sclerosis (MS) is the degeneration and loss of previously established functional myelin sheaths, which results in impaired signal propagation and axonal damage. However, at least in early disease stages, partial replacement of lost oligodendrocytes and thus remyelination occur as a result of resident oligodendroglial precursor cell (OPC) activation. These cells represent a widespread cell population within the adult central nervous system (CNS) that can differentiate into functional myelinating glial cells to restore axonal functions. Nevertheless, the spontaneous remyelination capacity in the adult CNS is inefficient because OPCs often fail to generate new oligodendrocytes due to the lack of stimulatory cues and the presence of inhibitory factors. Recent studies have provided evidence that regulated intracellular protein shuttling is functionally involved in oligodendroglial differentiation and remyelination activities. In this review we shed light on the role of the subcellular localization of differentiation-associated factors within oligodendroglial cells and show that regulation of intracellular localization of regulatory factors represents a crucial process to modulate oligodendroglial maturation and myelin repair in the CNS.
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11
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Transcriptional expression of myelin basic protein in oligodendrocytes depends on functional syntaxin 4: a potential correlation with autocrine signaling. Mol Cell Biol 2014; 35:675-87. [PMID: 25512606 DOI: 10.1128/mcb.01389-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myelination of axons by oligodendrocytes is essential for saltatory nerve conduction. To form myelin membranes, a coordinated synthesis and subsequent polarized transport of myelin components are necessary. Here, we show that as part of the mechanism to establish membrane polarity, oligodendrocytes exploit a polarized distribution of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) machinery components syntaxins 3 and 4, localizing to the cell body and the myelin membrane, respectively. Our data further reveal that the expression of myelin basic protein (MBP), a myelin-specific protein that is synthesized "on site" after transport of its mRNA, depends on the correct functioning of the SNARE machinery, which is not required for mRNA granule assembly and transport per se. Thus, downregulation and overexpression of syntaxin 4 but not syntaxin 3 in oligodendrocyte progenitor cells but not immature oligodendrocytes impeded MBP mRNA transcription, thereby preventing MBP protein synthesis. The expression and localization of another myelin-specific protein, proteolipid protein (PLP), was unaltered. Strikingly, conditioned medium obtained from developing oligodendrocytes was able to rescue the block of MBP mRNA transcription in syntaxin 4-downregulated cells. These findings indicate that the initiation of the biosynthesis of MBP mRNA relies on a syntaxin 4-dependent mechanism, which likely involves activation of an autocrine signaling pathway.
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Ozgen H, Schrimpf W, Hendrix J, de Jonge JC, Lamb DC, Hoekstra D, Kahya N, Baron W. The lateral membrane organization and dynamics of myelin proteins PLP and MBP are dictated by distinct galactolipids and the extracellular matrix. PLoS One 2014; 9:e101834. [PMID: 25003183 PMCID: PMC4086962 DOI: 10.1371/journal.pone.0101834] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/12/2014] [Indexed: 01/03/2023] Open
Abstract
In the central nervous system, lipid-protein interactions are pivotal for myelin maintenance, as these interactions regulate protein transport to the myelin membrane as well as the molecular organization within the sheath. To improve our understanding of the fundamental properties of myelin, we focused here on the lateral membrane organization and dynamics of peripheral membrane protein 18.5-kDa myelin basic protein (MBP) and transmembrane protein proteolipid protein (PLP) as a function of the typical myelin lipids galactosylceramide (GalC), and sulfatide, and exogenous factors such as the extracellular matrix proteins laminin-2 and fibronectin, employing an oligodendrocyte cell line, selectively expressing the desired galactolipids. The dynamics of MBP were monitored by z-scan point fluorescence correlation spectroscopy (FCS) and raster image correlation spectroscopy (RICS), while PLP dynamics in living cells were investigated by circular scanning FCS. The data revealed that on an inert substrate the diffusion rate of 18.5-kDa MBP increased in GalC-expressing cells, while the diffusion coefficient of PLP was decreased in sulfatide-containing cells. Similarly, when cells were grown on myelination-promoting laminin-2, the lateral diffusion coefficient of PLP was decreased in sulfatide-containing cells. In contrast, PLP's diffusion rate increased substantially when these cells were grown on myelination-inhibiting fibronectin. Additional biochemical analyses revealed that the observed differences in lateral diffusion coefficients of both proteins can be explained by differences in their biophysical, i.e., galactolipid environment, specifically with regard to their association with lipid rafts. Given the persistence of pathological fibronectin aggregates in multiple sclerosis lesions, this fundamental insight into the nature and dynamics of lipid-protein interactions will be instrumental in developing myelin regenerative strategies.
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Affiliation(s)
- Hande Ozgen
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Waldemar Schrimpf
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität, Munich, Germany
| | - Jelle Hendrix
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität, Munich, Germany
| | - Jenny C. de Jonge
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Don C. Lamb
- Physical Chemistry, Department of Chemistry, Munich Center for Integrated Protein Science (CiPSM) and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität, Munich, Germany
| | - Dick Hoekstra
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nicoletta Kahya
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail: (NK) (WB)
| | - Wia Baron
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail: (NK) (WB)
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