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Yoshikawa K. Necdin: A purposive integrator of molecular interaction networks for mammalian neuron vitality. Genes Cells 2021; 26:641-683. [PMID: 34338396 PMCID: PMC9290590 DOI: 10.1111/gtc.12884] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 12/29/2022]
Abstract
Necdin was originally found in 1991 as a hypothetical protein encoded by a neural differentiation‐specific gene transcript in murine embryonal carcinoma cells. Virtually all postmitotic neurons and their precursor cells express the necdin gene (Ndn) during neuronal development. Necdin mRNA is expressed only from the paternal allele through genomic imprinting, a placental mammal‐specific epigenetic mechanism. Necdin and its homologous MAGE (melanoma antigen) family, which have evolved presumedly from a subcomplex component of the SMC5/6 complex, are expressed exclusively in placental mammals. Paternal Ndn‐mutated mice totally lack necdin expression and exhibit various types of neuronal abnormalities throughout the nervous system. Ndn‐null neurons are vulnerable to detrimental stresses such as DNA damage. Necdin also suppresses both proliferation and apoptosis of neural stem/progenitor cells. Functional analyses using Ndn‐manipulated cells reveal that necdin consistently exerts antimitotic, anti‐apoptotic and prosurvival effects. Necdin interacts directly with a number of regulatory proteins including E2F1, p53, neurotrophin receptors, Sirt1 and PGC‐1α, which serve as major hubs of protein–protein interaction networks for mitosis, apoptosis, differentiation, neuroprotection and energy homeostasis. This review focuses on necdin as a pleiotropic protein that integrates molecular interaction networks to promote neuronal vitality in modern placental mammals.
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Abstract
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hyperphagia, hypotonia, learning disability, as well as a range of psychiatric conditions. The conservation of the PWS genetic interval on chromosome 15q11-q13 in human, and a cluster of genes on mouse chromosome 7, has facilitated the use of mice as animal models for PWS. Some models faithfully mimic the loss of all gene expression from the paternally inherited PWS genetic interval, whereas others target smaller regions or individual genes. Collectively, these models have provided insight into the mechanisms, many of which lead to alterations in hypothalamic function, underlying the core symptoms of PWS, including growth retardation, hyperphagia and metabolism, reproductive maturation and endophenotypes of relevance to behavioral and psychiatric problems. Here we review and summarize these studies.
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Affiliation(s)
- Simona Zahova
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Anthony R Isles
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom.
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Thamban T, Agarwaal V, Khosla S. Role of genomic imprinting in mammalian development. J Biosci 2020; 45:20. [PMID: 31965998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Non-mendelian inheritance refers to the group of phenomena and observations related to the inheritance of genetic information that cannot be merely explained by Mendel's laws of inheritance. Phenomenon including Genomic imprinting, X-chromosome Inactivation, Paramutations are some of the best studied examples of non-mendelian inheritance. Genomic imprinting is a process that reversibly marks one of the two homologous loci, chromosome or chromosomal sets during development, resulting in functional non-equivalence of gene expression. Genomic imprinting is known to occur in a few insect species, plants, and placental mammals. Over the years, studies on imprinted genes have contributed immensely to highlighting the role of epigenetic modifications and the epigenetic circuitry during gene expression and development. In this review, we discuss the phenomenon of genomic imprinting in mammals and the role it plays especially during fetoplacental growth and early development.
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Affiliation(s)
- Thushara Thamban
- Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India
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Carias KV, Wevrick R. Preclinical Testing in Translational Animal Models of Prader-Willi Syndrome: Overview and Gap Analysis. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:344-358. [PMID: 30989085 PMCID: PMC6447752 DOI: 10.1016/j.omtm.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder causing endocrine, musculoskeletal, and neurological dysfunction. PWS is caused by the inactivation of contiguous genes, complicating the development of targeted therapeutics. Clinical trials are now underway in PWS, with more trials to be implemented in the next few years. PWS-like endophenotypes are recapitulated in gene-targeted mice in which the function of one or more PWS genes is disrupted. These animal models can guide priorities for clinical trials or provide information about efficacy of a compound within the context of the specific disease. We now review the current status of preclinical studies that measure the effect of therapeutics on PWS-like endophenotypes. Seven categories of therapeutics (oxytocin and related compounds, K+-ATP channel agonists, melanocortin 4 receptor agonists, incretin mimetics and/or GLP-1 receptor agonists, cannabinoids, ghrelin agents, and Caralluma fimbriata [cactus] extract) have been tested for their effect on endophenotypes in both PWS animal models and clinical trials. Many other therapeutics have been tested in clinical trials, but not preclinical models of PWS or vice versa. Fostering dialogs among investigators performing preclinical validation of animal models and those implementing clinical studies will accelerate the discovery and translation of therapies into clinical practice in PWS.
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Affiliation(s)
- K Vanessa Carias
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
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Matarazzo V, Caccialupi L, Schaller F, Shvarev Y, Kourdougli N, Bertoni A, Menuet C, Voituron N, Deneris E, Gaspar P, Bezin L, Durbec P, Hilaire G, Muscatelli F. Necdin shapes serotonergic development and SERT activity modulating breathing in a mouse model for Prader-Willi syndrome. eLife 2017; 6:32640. [PMID: 29087295 PMCID: PMC5711373 DOI: 10.7554/elife.32640] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 10/29/2017] [Indexed: 12/31/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a genetic neurodevelopmental disorder that presents with hypotonia and respiratory distress in neonates. The Necdin-deficient mouse is the only model that reproduces the respiratory phenotype of PWS (central apnea and blunted response to respiratory challenges). Here, we report that Necdin deletion disturbs the migration of serotonin (5-HT) neuronal precursors, leading to altered global serotonergic neuroarchitecture and increased spontaneous firing of 5-HT neurons. We show an increased expression and activity of 5-HT Transporter (SERT/Slc6a4) in 5-HT neurons leading to an increase of 5-HT uptake. In Necdin-KO pups, the genetic deletion of Slc6a4 or treatment with Fluoxetine, a 5-HT reuptake inhibitor, restored normal breathing. Unexpectedly, Fluoxetine administration was associated with respiratory side effects in wild-type animals. Overall, our results demonstrate that an increase of SERT activity is sufficient to cause the apneas in Necdin-KO pups, and that fluoxetine may offer therapeutic benefits to PWS patients with respiratory complications. Prader-Willi syndrome results from the disruption of a cluster of neighboring genes, including one called Necdin. Symptoms begin in early infancy and worsen with age. Affected children tend to develop an insatiable appetite, which often leads to obesity. They also experience serious problems with their breathing. Chest infections, high altitude and intense physical activity can be dangerous for children with Prader-Willi syndrome. This is because a slight shortage of oxygen may trigger breathing difficulties that could prove fatal. The brain cells that produce a chemical messenger called serotonin help to control breathing. Several lines of evidence suggest that loss of Necdin may trigger breathing difficulties in Prader-Willi syndrome via effects on the serotonin system. First, serotonin neurons produce the Necdin protein. Second, laboratory mice that lack the gene for Necdin have abnormally shaped serotonin neurons. Third, these mice show breathing difficulties like those of individuals with Prader-Willi syndrome. But while this implies a connection between serotonin, Necdin and breathing difficulties, it falls short of establishing a causal link. Matarazzo et al. now reveal an increase in the quantity and activity of a protein called the serotonin transporter in mutant mice that lacked the gene for Necdin compared to normal mice. Serotonin transporter proteins mop up the serotonin that neurons release when they signal to one another. Neurons in the mutant mice take up more serotonin than their counterparts in normal mice; this means they have less serotonin available for signaling. This may make it harder for the mutant mice to regulate their breathing. Drugs called selective serotonin-reuptake inhibitors (or SSRIs for short) can block the serotonin transporter. These drugs, which include Fluoxetine (also called Prozac), are antidepressants. Matarazzo et al. show that SSRIs temporarily restore normal breathing in young mice that lack the gene for Necdin. However, these drugs have harmful long-term effects on breathing in non-mutant mice. Further studies should test whether short-term use of SSRIs could offer immediate relief for breathing difficulties in infants and children with Prader-Willi syndrome.
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Affiliation(s)
| | | | | | - Yuri Shvarev
- Department of Women's and Children's Health, Karolinska Institute, Solna, Sweden
| | | | | | | | | | - Evan Deneris
- Department of Neurosciences, Case Western Reserve University, Cleveland, United States
| | - Patricia Gaspar
- UPMC Univ Paris 6, Institut du Fer à Moulin, INSERM, Paris, France
| | - Laurent Bezin
- Lyon Neuroscience Research Center, Université de Lyon, INSERM, CNRS, Lyon, France
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Fujimoto I, Hasegawa K, Fujiwara K, Yamada M, Yoshikawa K. Necdin controls EGFR signaling linked to astrocyte differentiation in primary cortical progenitor cells. Cell Signal 2015; 28:94-107. [PMID: 26655377 DOI: 10.1016/j.cellsig.2015.11.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/23/2015] [Accepted: 11/30/2015] [Indexed: 11/26/2022]
Abstract
Cellular signaling mediated by the EGF receptor (EGFR) plays a key role in controlling proliferation and differentiation of cortical progenitor cells (CPCs). However, regulatory mechanisms of EGFR signaling in CPCs remain largely unknown. Here we demonstrate that necdin, a MAGE (melanoma antigen) family protein, interacts with EGFR in primary CPCs and represses its downstream signaling linked to astrocyte differentiation. EGFR was autophosphorylated and interacted with necdin in EGF-stimulated CPCs. Necdin bound to autophosphorylated EGFR via its tyrosine kinase domain. EGF-induced phosphorylation of ERK was enhanced in necdin-null CPCs, where the interaction between EGFR and the adaptor protein Grb2 was strengthened, suggesting that endogenous necdin suppresses the EGFR/ERK signaling pathway in CPCs. In necdin-null CPCs, astrocyte differentiation induced by the gliogenic cytokine cardiotrophin-1 was significantly accelerated in the presence of EGF, and inhibition of EGFR/ERK signaling abolished the acceleration. Furthermore, necdin strongly suppressed astrocyte differentiation induced by overexpression of EGFR or its ligand binding-defective mutant equivalent to a glioblastoma-associated EGFR variant. These results suggest that necdin acts as an intrinsic suppressor of the EGFR/ERK signaling pathway in EGF-responsive CPCs to restrain astroglial development in a cell-autonomous manner.
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Affiliation(s)
- Izumi Fujimoto
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Koichi Hasegawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Kazushiro Fujiwara
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Masashi Yamada
- Laboratory of Extracellular Matrix Biochemistry, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Kazuaki Yoshikawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan.
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Reus L, Pillen S, Pelzer BJ, van Alfen-van der Velden JAAEM, Hokken-Koelega ACS, Zwarts M, Otten BJ, Nijhuis-van der Sanden MWG. Growth hormone therapy, muscle thickness, and motor development in Prader-Willi syndrome: an RCT. Pediatrics 2014; 134:e1619-27. [PMID: 25422026 DOI: 10.1542/peds.2013-3607] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To investigate the effect of physical training combined with growth hormone (GH) on muscle thickness and its relationship with muscle strength and motor development in infants with Prader-Willi syndrome (PWS). METHODS In a randomized controlled trial, 22 infants with PWS (12.9 ± 7.1 months) were followed over 2 years to compare a treatment group (n = 10) with a waiting-list control group (n = 12). Muscle thickness of 4 muscle groups was measured by using ultrasound. Muscle strength was evaluated by using the Infant Muscle Strength meter. Motor performance was measured with the Gross Motor Function Measurement. Analyses of variance were used to evaluate between-group effects of GH on muscle thickness at 6 months and to compare pre- and posttreatment (after 12 months of GH) values. Multilevel analyses were used to evaluate effects of GH on muscle thickness over time, and multilevel bivariate analyses were used to test relationships between muscle thickness, muscle strength, and motor performance. RESULTS A significant positive effect of GH on muscle thickness (P < .05) was found. Positive relationships were found between muscle thickness and muscle strength (r = 0.61, P < .001), muscle thickness and motor performance (r = 0.81, P < .001), and muscle strength and motor performance (r = 0.76, P < .001). CONCLUSIONS GH increased muscle thickness, which was related to muscle strength and motor development in infants with PWS. Catch-up growth was faster in muscles that are most frequently used in early development. Because this effect was independent of GH, it suggests a training effect.
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Affiliation(s)
- Linda Reus
- Department of Rehabilitation, Pediatric Physical Therapy, Scientific Institute for Quality of Healthcare,
| | - Sigrid Pillen
- Child Development and Exercise Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands
| | | | | | - Anita C S Hokken-Koelega
- Dutch Growth Research Foundation, Rotterdam, Netherlands; Department of Pediatric Endocrinology, Erasmus Medical Centre Rotterdam, Rotterdam, Netherlands; and
| | | | - Barto J Otten
- Department of Pediatric Endocrinology, Radboud University Medical Center, Nijmegen, Netherlands
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Gur I, Fujiwara K, Hasegawa K, Yoshikawa K. Necdin promotes ubiquitin-dependent degradation of PIAS1 SUMO E3 ligase. PLoS One 2014; 9:e99503. [PMID: 24911587 PMCID: PMC4049815 DOI: 10.1371/journal.pone.0099503] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 05/15/2014] [Indexed: 01/09/2023] Open
Abstract
Necdin, a pleiotropic protein that promotes differentiation and survival of mammalian neurons, is a member of MAGE (melanoma antigen) family proteins that share a highly conserved MAGE homology domain. Several MAGE proteins interact with ubiquitin E3 ligases and modulate their activities. However, it remains unknown whether MAGE family proteins interact with SUMO (small ubiquitin-like modifier) E3 ligases such as PIAS (protein inhibitor of activated STAT) family, Nsmce2/Mms21 and Cbx4/Pc2. In the present study, we examined whether necdin interacts with these SUMO E3 ligases. Co-immunoprecipitation analysis revealed that necdin, MAGED1, MAGEF1 and MAGEL2 bound to PIAS1 but not to Nsmce2 or Cbx4. These SUMO E3 ligases bound to MAGEA1 but failed to interact with necdin-like 2/MAGEG1. Necdin bound to PIAS1 central domains that are highly conserved among PIAS family proteins and suppressed PIAS1-dependent sumoylation of the substrates STAT1 and PML (promyelocytic leukemia protein). Remarkably, necdin promoted degradation of PIAS1 via the ubiquitin-proteasome pathway. In transfected HEK293A cells, amino- and carboxyl-terminally truncated mutants of PIAS1 bound to necdin but failed to undergo necdin-dependent ubiquitination. Both PIAS1 and necdin were associated with the nuclear matrix, where the PIAS1 terminal deletion mutants failed to localize, implying that the nuclear matrix is indispensable for necdin-dependent ubiquitination of PIAS1. Our data suggest that necdin suppresses PIAS1 both by inhibiting SUMO E3 ligase activity and by promoting ubiquitin-dependent degradation.
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Affiliation(s)
- Ibrahim Gur
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kazushiro Fujiwara
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Koichi Hasegawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kazuaki Yoshikawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
- * E-mail:
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CLAC-P/collagen type XXV is required for the intramuscular innervation of motoneurons during neuromuscular development. J Neurosci 2014; 34:1370-9. [PMID: 24453327 DOI: 10.1523/jneurosci.2440-13.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Formation of proper neuromuscular connections is a process coordinated by both motoneuron-intrinsic and target-dependent programs. Under these programs, motoneurons innervate target muscles, escape programmed cell death during fetal development, and form neuromuscular junctions (NMJ). Although a number of studies have revealed molecules involved in axon guidance to target muscles and NMJ formation, little is known about the molecular mechanisms linking intramuscular innervation and target-derived trophic factor-dependent prevention of motoneuron apoptosis. Here we studied the physiological function of CLAC-P/collagen XXV, a transmembrane-type collagen originally identified as a component of senile plaque amyloid of Alzheimer's disease brains, by means of generating Col25a1-deficient (KO) mice. Col25a1 KO mice died immediately after birth of respiratory failure. In Col25a1 KO mice, motor axons projected properly toward the target muscles but failed to elongate and branch within the muscle, followed by degeneration of axons. Failure of muscular innervation in Col25a1 KO mice led to excessive apoptosis during development, resulting in almost complete and exclusive loss of spinal motoneurons and immaturity in skeletal muscle development. Bax deletion in Col25a1 KO mice rescued motoneurons from apoptosis, although motor axons remained halted around the muscle entry site. Furthermore, these motoneurons were positive for phosphorylated c-Jun, an indicator of insufficient supply of target-derived survival signals. Together, these observations indicate that CLAC-P/collagen XXV is a novel essential factor that regulates the initial phase of intramuscular motor innervation, which is required for subsequent target-dependent motoneuron survival and NMJ formation during development.
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The linker histone h1.2 is an intermediate in the apoptotic response to cytokine deprivation in T-effectors. Int J Cell Biol 2014; 2014:674753. [PMID: 24688545 PMCID: PMC3943393 DOI: 10.1155/2014/674753] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/03/2014] [Accepted: 01/05/2014] [Indexed: 11/17/2022] Open
Abstract
Tissue homeostasis is a dynamic process involving proliferation and the removal of redundant or damaged cells. This is exemplified in the coordinated deletion—triggered by limiting trophic factors/cytokines in the extracellular milieu—of differentiated T cells overproduced during the mammalian immune response. However, mechanisms by which extracellular cues are perceived and transduced as apoptotic triggers remain incompletely understood. T-effectors are dependent on cytokines for survival and undergo apoptosis following cytokine withdrawal. Here we report that leptomycin B (LMB), an inhibitor of nuclear export machinery, protected T-effectors from apoptosis implicating a nuclear intermediate in the apoptotic pathway. Evidence is presented that the linker histone H1.2 localizes to the cytoplasm, by a mechanism sensitive to regulation by LMB, to activate apoptotic signaling culminating in nuclear and mitochondrial damage in T-effectors in response to cytokine deprivation. H1.2 is detected in a complex with the proapoptotic mitochondrial resident Bak and its subcellular localization regulated by Jun-N-terminal kinase (JNK), an intermediate in the apoptotic cascade in T-effectors. These data suggest that metabolic stressors may impinge on H1.2 dynamics favoring its activity at the mitochondrion, thereby functioning as a molecular switch for T-effector apoptosis.
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Minamide R, Fujiwara K, Hasegawa K, Yoshikawa K. Antagonistic interplay between necdin and Bmi1 controls proliferation of neural precursor cells in the embryonic mouse neocortex. PLoS One 2014; 9:e84460. [PMID: 24392139 PMCID: PMC3879318 DOI: 10.1371/journal.pone.0084460] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 11/21/2013] [Indexed: 01/07/2023] Open
Abstract
Neural precursor cells (NPCs) in the neocortex exhibit a high proliferation capacity during early embryonic development and give rise to cortical projection neurons after maturation. Necdin, a mammal-specific MAGE (melanoma antigen) family protein that possesses anti-mitotic and pro-survival activities, is expressed abundantly in postmitotic neurons and moderately in tissue-specific stem cells or progenitors. Necdin interacts with E2F transcription factors and suppresses E2F1-dependent transcriptional activation of the cyclin-dependent kinase Cdk1 gene. Here we show that necdin serves as a suppressor of NPC proliferation in the embryonic neocortex. Necdin is moderately expressed in the ventricular zone of mouse embryonic neocortex, in which proliferative cell populations are significantly increased in necdin-null mice. In the neocortex of necdin-null embryos, expression of Cdk1 and Sox2, a stem cell marker, is significantly increased, whereas expression of p16, a cyclin-dependent kinase inhibitor, is markedly diminished. Cdk1 and p16 expression levels are also significantly increased and decreased, respectively, in primary NPCs prepared from necdin-null embryos. Intriguingly, necdin interacts directly with Bmi1, a Polycomb group protein that suppresses p16 expression and promotes NPC proliferation. In HEK293A cells transfected with luciferase reporter constructs, necdin relieves Bmi1-dependent repression of p16 promoter activity, whereas Bmi1 counteracts necdin-mediated repression of E2F1-dependent Cdk1 promoter activity. In lentivirus-infected primary NPCs, necdin overexpression increases p16 expression, suppresses Cdk1 expression, and inhibits NPC proliferation, whereas Bmi1 overexpression suppresses p16 expression, increases Cdk1 expression, and promotes NPC proliferation. Our data suggest that embryonic NPC proliferation in the neocortex is regulated by the antagonistic interplay between necdin and Bmi1.
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Affiliation(s)
- Ryohei Minamide
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kazushiro Fujiwara
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Koichi Hasegawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kazuaki Yoshikawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
- * E-mail:
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Rieusset A, Schaller F, Unmehopa U, Matarazzo V, Watrin F, Linke M, Georges B, Bischof J, Dijkstra F, Bloemsma M, Corby S, Michel FJ, Wevrick R, Zechner U, Swaab D, Dudley K, Bezin L, Muscatelli F. Stochastic loss of silencing of the imprinted Ndn/NDN allele, in a mouse model and humans with prader-willi syndrome, has functional consequences. PLoS Genet 2013; 9:e1003752. [PMID: 24039599 PMCID: PMC3764186 DOI: 10.1371/journal.pgen.1003752] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/10/2013] [Indexed: 12/27/2022] Open
Abstract
Genomic imprinting is a process that causes genes to be expressed from one allele only according to parental origin, the other allele being silent. Diseases can arise when the normally active alleles are not expressed. In this context, low level of expression of the normally silent alleles has been considered as genetic noise although such expression has never been further studied. Prader-Willi Syndrome (PWS) is a neurodevelopmental disease involving imprinted genes, including NDN, which are only expressed from the paternally inherited allele, with the maternally inherited allele silent. We present the first in-depth study of the low expression of a normally silent imprinted allele, in pathological context. Using a variety of qualitative and quantitative approaches and comparing wild-type, heterozygous and homozygous mice deleted for Ndn, we show that, in absence of the paternal Ndn allele, the maternal Ndn allele is expressed at an extremely low level with a high degree of non-genetic heterogeneity. The level of this expression is sex-dependent and shows transgenerational epigenetic inheritance. In about 50% of mutant mice, this expression reduces birth lethality and severity of the breathing deficiency, correlated with a reduction in the loss of serotonergic neurons. In wild-type brains, the maternal Ndn allele is never expressed. However, using several mouse models, we reveal a competition between non-imprinted Ndn promoters which results in monoallelic (paternal or maternal) Ndn expression, suggesting that Ndn allelic exclusion occurs in the absence of imprinting regulation. Importantly, specific expression of the maternal NDN allele is also detected in post-mortem brain samples of PWS individuals. Our data reveal an unexpected epigenetic flexibility of PWS imprinted genes that could be exploited to reactivate the functional but dormant maternal alleles in PWS. Overall our results reveal high non-genetic heterogeneity between genetically identical individuals that might underlie the variability of the phenotype.
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Affiliation(s)
- Anne Rieusset
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - Fabienne Schaller
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - Unga Unmehopa
- Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Valery Matarazzo
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - Françoise Watrin
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - Matthias Linke
- Universitätsmedizin der Johannes Gutenberg-Universität Mainz Institut für Humangenetik, Mainz, Germany
| | - Beatrice Georges
- INSERM, U1028, CNRS, UMR5292, Université Claude Bernard Lyon 1, Lyon Neuroscience Center, Villeurbanne, France
| | - Jocelyn Bischof
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Femke Dijkstra
- Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Monique Bloemsma
- Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Severine Corby
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - François J. Michel
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Ulrich Zechner
- Universitätsmedizin der Johannes Gutenberg-Universität Mainz Institut für Humangenetik, Mainz, Germany
| | - Dick Swaab
- Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Keith Dudley
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
| | - Laurent Bezin
- INSERM, U1028, CNRS, UMR5292, Université Claude Bernard Lyon 1, Lyon Neuroscience Center, Villeurbanne, France
| | - Françoise Muscatelli
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED) U901, Marseille, France
- Aix-Marseille Université, INMED UMR901, Marseille, France
- * E-mail:
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Death Receptors in the Selective Degeneration of Motoneurons in Amyotrophic Lateral Sclerosis. JOURNAL OF NEURODEGENERATIVE DISEASES 2013; 2013:746845. [PMID: 26316997 PMCID: PMC4437334 DOI: 10.1155/2013/746845] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/28/2013] [Indexed: 12/13/2022]
Abstract
While studies on death receptors have long been restricted to immune cells, the last decade has provided a strong body of evidence for their implication in neuronal death and hence neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS). ALS is a fatal paralytic disorder that primarily affects motoneurons in the brain and spinal cord. A neuroinflammatory process, associated with astrocyte and microglial activation as well as infiltration of immune cells, accompanies motoneuron degeneration and supports the contribution of non-cell-autonomous mechanisms in the disease. Hallmarks of Fas, TNFR, LT-βR, and p75NTR signaling have been observed in both animal models and ALS patients. This review summarizes to date knowledge of the role of death receptors in ALS and the link existing between the selective loss of motoneurons and neuroinflammation. It further suggests how this recent evidence could be included in an ultimate multiapproach to treat patients.
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Recommendations for the investigation of animal models of Prader-Willi syndrome. Mamm Genome 2013; 24:165-78. [PMID: 23609791 DOI: 10.1007/s00335-013-9454-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/11/2013] [Indexed: 12/28/2022]
Abstract
Prader-Willi syndrome (PWS) occurs in about 1 in 15,000 individuals and is a contiguous gene disorder causing developmental disability, hyperphagia usually with obesity, and behavioral problems, including an increased incidence of psychiatric illness. The genomic imprinting that regulates allele-specific expression of PWS candidate genes, the fact that multiple genes are typically inactivated, and the presence of many genes that produce functional RNAs rather than proteins has complicated the identification of the underlying genetic pathophysiology of PWS. Over 30 genetically modified mouse strains that have been developed and characterized have been instrumental in elucidating the genetic and epigenetic mechanisms for the regulation of PWS genes and in discovering their physiological functions. In 2011, a PWS Animal Models Working Group (AMWG) was established to generate discussions and facilitate exchange of ideas regarding the best use of PWS animal models. Here, we summarize the goals of the AMWG, describe current animal models of PWS, and make recommendations for strategies to maximize the utility of animal models and for the development and use of new animal models of PWS.
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16
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Age-dependent modulation of cortical transcriptomes in spinal cord injury and repair. PLoS One 2012; 7:e49812. [PMID: 23236355 PMCID: PMC3517588 DOI: 10.1371/journal.pone.0049812] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/16/2012] [Indexed: 11/19/2022] Open
Abstract
Both injury and aging of the central nervous system reportedly produce profound changes in gene expression. Therefore, aging may interfere with the success of therapeutic interventions which were tailored for young patients. Using genome-scale transcriptional profiling, we identified distinct age-dependent expression profiles in rat sensorimotor cortex during acute, subacute and chronic phases of spinal cord injury (SCI). Aging affects the cortical transcriptomes triggered by transection of the corticospinal tract as there was only a small overlap between the significantly lesion-regulated genes in both age groups. Over-representation analysis of the lesion-regulated genes revealed that, in addition to biological processes in common, such as lipid metabolism, others, such as activation of complement cascade, were specific for aged animals. When a recently developed treatment to suppress fibrotic scarring (anti-scarring treatment AST) was applied to the injured spinal cord of aged (22 months) and young (2 months) rats, we found that the cortical gene expression in old rats was modulated to resemble regeneration-associated profiles of young animals including the up-regulation of known repair promoting growth and transcription factors at 35 dpo. In combination with recent immunohistochemical findings demonstrating regenerative axon growth upon AST in aged animals, the present investigation on the level of gene expression strongly supports the feasibility of a successful AST therapy in elderly patients.
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Lavi-Itzkovitz A, Tcherpakov M, Levy Z, Itzkovitz S, Muscatelli F, Fainzilber M. Functional consequences of necdin nucleocytoplasmic localization. PLoS One 2012; 7:e33786. [PMID: 22442722 PMCID: PMC3307762 DOI: 10.1371/journal.pone.0033786] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 02/19/2012] [Indexed: 02/02/2023] Open
Abstract
Background Necdin, a MAGE family protein expressed primarily in the nervous system, has been shown to interact with both nuclear and cytoplasmic proteins, but the mechanism of its nucleocytoplasmic transport are unknown. Methodology/Principal Findings We carried out a large-scale interaction screen using necdin as a bait in the yeast RRS system, and found a wide range of potential interactors with different subcellular localizations, including over 60 new candidates for direct binding to necdin. Integration of these interactions into a comprehensive network revealed a number of coherent interaction modules, including a cytoplasmic module connecting to necdin through huntingtin-associated protein 1 (Hap1), dynactin and hip-1 protein interactor (Hippi); a nuclear P53 and Creb-binding-protein (Crebbp) module, connecting through Crebbp and WW domain-containing transcription regulator protein 1 (Wwtr1); and a nucleocytoplasmic transport module, connecting through transportins 1 and 2. We validated the necdin-transportin1 interaction and characterized a sequence motif in necdin that modulates karyopherin interaction. Surprisingly, a D234P necdin mutant showed enhanced binding to both transportin1 and importin β1. Finally, exclusion of necdin from the nucleus triggered extensive cell death. Conclusions/Significance These data suggest that necdin has multiple roles within protein complexes in different subcellular compartments, and indicate that it can utilize multiple karyopherin-dependent pathways to modulate its localization.
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Affiliation(s)
- Anat Lavi-Itzkovitz
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Marianna Tcherpakov
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Zehava Levy
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Shalev Itzkovitz
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Francoise Muscatelli
- Institut de Neurobiologie de la Méditerranée, INSERM U901, Parc Scientifique de Luminy BP 13, Marseille, France
| | - Mike Fainzilber
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
- * E-mail:
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Mercer RE, Wevrick R. Energy homeostasis in Prader-Willi syndrome: how clinical research informs studies of animal models of genetic obesity: comment on "Nutritional phases in Prader-Willi syndrome," Miller et al., 2011. Am J Med Genet Part A, 155:1040-1049. Am J Med Genet A 2012; 158A:966-8. [PMID: 22419655 DOI: 10.1002/ajmg.a.35249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 12/26/2011] [Indexed: 11/06/2022]
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19
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Bush JR, Wevrick R. Loss of the Prader-Willi obesity syndrome protein necdin promotes adipogenesis. Gene 2012; 497:45-51. [PMID: 22305984 DOI: 10.1016/j.gene.2012.01.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 01/19/2012] [Indexed: 01/07/2023]
Abstract
We investigated the role of necdin during adipogenic differentiation. Necdin is one of several genes inactivated in children with Prader-Willi syndrome, who are predisposed to increased adiposity at the expense of lean mass. Necdin promotes neuronal and muscle differentiation and survival through interactions with a variety of proteins, including cell surface receptors, modifiers of protein stability, and transcription factors. In pre-adipocytes, necdin over-expression inhibits adipogenesis, while reducing necdin levels enhances adipogenic differentiation in tissue culture cells. We now directly demonstrate a role for necdin in inhibiting adipogenesis using cells derived from necdin deficient mice.
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Affiliation(s)
- Jason Russell Bush
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
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