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Silk T, Dipnall L, Wong YT, Craig JM. Epigenetics and ADHD. Curr Top Behav Neurosci 2022; 57:269-289. [PMID: 35505060 DOI: 10.1007/7854_2022_339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
There is robust evidence of genetic susceptibility to Attention-Deficit Hyperactivity Disorder (ADHD); however, there still remains significant variability that is not attributable to genetic factors. The emerging field of epigenetics is beginning to reveal how genotypic expression can be mediated by an array of variables including external environmental exposure, inter-individual developmental variation, and by the genome itself. Epigenetic modification plays a central role in neurobiological and developmental processes, and disturbances to these processes can have implications for a range of mental health problems. Although the field is still in its early days, this chapter will discuss the current standing of epigenetic research into ADHD. Firstly, key relevant epigenetic processes will be discussed. This will be followed by an overview of the key findings to date investigating the role of epigenetics in ADHD. Human studies have included the theory-driven approach of candidate-gene studies (CGS), as well as the increasingly popular exploratory approach of epigenome-wide association studies (EWAS). Overall, the findings are heterogeneous. However, it is possible that with more longitudinal studies and better characterised cohorts, both predictive and protective links between epigenetic processes and ADHD will be revealed.
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Affiliation(s)
- Timothy Silk
- Centre for Social and Early Emotional Development and School of Psychology, Deakin University, Geelong, VIC, Australia. .,Murdoch Children's Research Institute, Parkville, VIC, Australia.
| | - Lillian Dipnall
- Centre for Social and Early Emotional Development and School of Psychology, Deakin University, Geelong, VIC, Australia
| | - Yen Ting Wong
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Jeffrey M Craig
- Murdoch Children's Research Institute, Parkville, VIC, Australia.,Institute for Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Geelong, VIC, Australia
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Shojaeian S, Moazeni-Roodi A, Allameh A, Garajei A, Kazemnejad A, Kabir K, Zarnani AH. Methylation of TGM-3 Promoter and Its Association with Oral Squamous Cell Carcinoma (OSCC). Avicenna J Med Biotechnol 2021; 13:65-73. [PMID: 34012521 PMCID: PMC8112137 DOI: 10.18502/ajmb.v13i2.5523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background: Oral Squamous Cell Carcinoma (OSCC) is among the ten most common cancers worldwide. Hypermethylation of CpG sites in the promoter region and subsequent down-regulation of a tumor suppressor gene, TGM-3 has been proposed to be linked to different types of human cancers including OSCC. In this study, methylation status of CpG sites in the promoter region of TGM-3 has been evaluated in a cohort of patients with OSCC compared to normal controls. Methods: Forty fresh tissue samples were obtained from newly diagnosed OSCC patients and normal individuals referred to dentistry clinic for tooth extraction. DNA was extracted, bisulfite conversion was performed and it was subjected to PCR using bisulfite-sequencing PCR (BSP) primers. Prepared samples were sequenced on a DNA analyzer with both forward and reverse primers of the region of interest. The peak height values of cytosine and thymine were calculated and methylation levels for each CpG site within the DNA sequence was quantified. Results: Quantitative DNA methylation analyses in CpG islands revealed that it was significantly higher in OSCC patients compared to controls. DNA methylation at CpG1/CpG3/CpG5 (p=0.004–0.01) and CpG1/CpG3 (p=0.001–0.019) sites was associated with tumor stage and grade, respectively. Male OSCC patients had higher methylation rate at CpG3 (p=0.032), while smoker patients showed higher methylation rate at CpG6 (p=0.045). Conclusion: These results manifested the contribution of DNA methylation of TGM-3 in OSCC and its potential association with clinico-pathologic parameters in OSCC.
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Affiliation(s)
- Sorour Shojaeian
- Department of Biochemistry, Alborz University of Medical Sciences, Karaj, Iran
| | | | - Abdolamir Allameh
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ata Garajei
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.,Department of Head and Neck Surgical Oncology and Reconstructive Surgery, The Cancer Institute, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Anoshirvan Kazemnejad
- Department of Bio-statistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Kourosh Kabir
- Department of Community Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Amir-Hassan Zarnani
- Department of Immunology, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, Iran.,Reproductive Immunology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
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Transcription factor LSF-DNMT1 complex dissociation by FQI1 leads to aberrant DNA methylation and gene expression. Oncotarget 2018; 7:83627-83640. [PMID: 27845898 PMCID: PMC5347793 DOI: 10.18632/oncotarget.13271] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/13/2016] [Indexed: 12/19/2022] Open
Abstract
The transcription factor LSF is highly expressed in hepatocellular carcinoma (HCC) and promotes oncogenesis. Factor quinolinone inhibitor 1 (FQI1), inhibits LSF DNA-binding activity and exerts anti-proliferative activity. Here, we show that LSF binds directly to the maintenance DNA (cytosine-5) methyltransferase 1 (DNMT1) and its accessory protein UHRF1 both in vivo and in vitro. Binding of LSF to DNMT1 stimulated DNMT1 activity and FQI1 negated the methyltransferase activation. Addition of FQI1 to the cell culture disrupted LSF bound DNMT1 and UHRF1 complexes, resulting in global aberrant CpG methylation. Differentially methylated regions (DMR) containing at least 3 CpGs, were significantly altered by FQI1 compared to control cells. The DMRs were mostly concentrated in CpG islands, proximal to transcription start sites, and in introns and known genes. These DMRs represented both hypo and hypermethylation, correlating with altered gene expression. FQI1 treatment elicits a cascade of effects promoting altered cell cycle progression. These findings demonstrate a novel mechanism of FQI1 mediated alteration of the epigenome by DNMT1-LSF complex disruption, leading to aberrant DNA methylation and gene expression.
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Abstract
The role of DNA methylation in brain development is an intense area of research because the brain has particularly high levels of CpG and mutations in many of the proteins involved in the establishment, maintenance, interpretation, and removal of DNA methylation impact brain development and/or function. These include DNA methyltransferase (DNMT), Ten-Eleven Translocation (TET), and Methyl-CpG binding proteins (MBPs). Recent advances in sequencing breadth and depth as well the detection of different forms of methylation have greatly expanded our understanding of the diversity of DNA methylation in the brain. The contributions of DNA methylation and associated proteins to embryonic and adult neurogenesis will be examined. Particular attention will be given to the impact on adult hippocampal neurogenesis (AHN), which is a key mechanism contributing to brain plasticity, learning, memory and mood regulation. DNA methylation influences multiple aspects of neurogenesis from stem cell maintenance and proliferation, fate specification, neuronal differentiation and maturation, and synaptogenesis. In addition, DNA methylation during neurogenesis has been shown to be responsive to many extrinsic signals, both under normal conditions and during disease and injury. Finally, crosstalk between DNA methylation, Methyl-DNA binding domain (MBD) proteins such as MeCP2 and MBD1 and histone modifying complexes is used as an example to illustrate the extensive interconnection between these epigenetic regulatory systems.
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Affiliation(s)
- Emily M Jobe
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Xinyu Zhao
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI, USA.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
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5
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Abstract
Astrocytes abound in the human central nervous system (CNS) and play a multitude of indispensable roles in neuronal homeostasis and regulation of synaptic plasticity. While traditionally considered to be merely ancillary supportive cells, their complex yet fundamental relevance to brain physiology and pathology have only become apparent in recent times. Beyond their myriad canonical functions, previously unrecognised region-specific functional heterogeneity of astrocytes is emerging as an important attribute and challenges the traditional perspective of CNS-wide astrocyte homogeneity. Animal models have undeniably provided crucial insights into astrocyte biology, yet interspecies differences may limit the translational yield of such studies. Indeed, experimental systems aiming to understand the function of human astrocytes in health and disease have been hampered by accessibility to enriched cultures. Human induced pluripotent stem cells (hiPSCs) now offer an unparalleled model system to interrogate the role of astrocytes in neurodegenerative disorders. By virtue of their ability to convey mutations at pathophysiological levels in a human system, hiPSCs may serve as an ideal pre-clinical platform for both resolution of pathogenic mechanisms and drug discovery. Here, we review astrocyte specification from hiPSCs and discuss their role in modelling human neurological diseases.
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Sudo G, Kagawa T, Kokubu Y, Inazawa J, Taga T. Increase in GFAP-positive astrocytes in histone demethylase GASC1/KDM4C/JMJD2C hypomorphic mutant mice. Genes Cells 2016; 21:218-25. [PMID: 26805559 DOI: 10.1111/gtc.12331] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 11/27/2015] [Indexed: 01/06/2023]
Abstract
GASC1, also known as KDM4C/JMJD2C, is a histone demethylase for histone H3 lysine 9 (H3K9) and H3K36. In this study, we observed an increase of GFAP-positive astrocytes in the brain of Gasc1 hypomorphic mutant mice at 2-3 months of age, but not at postnatal day 14 and day 30 by immunohistochemistry. Increases of GFAP-positive astrocytes were widely observed in the forebrain and prominent in such regions as cerebral cortex, caudate putamen, amygdala and diencephalon, but not obvious in hippocampus. Taken together with our observations to be published elsewhere that Gasc1 hypomorphic mutant mice exhibit abnormal behaviors including hyperactivity, persistence and many types of learning and memory deficits and abnormal synaptic functions such as prolonged long-term potentiation, the increase in GFAP-positive astrocytes may help understand their phenotypes, because astrocytes are known to affect synaptic plasticity.
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Affiliation(s)
- Genki Sudo
- Department of Stem Cell regulation, Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Tetsushi Kagawa
- Department of Stem Cell regulation, Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Yasuhiro Kokubu
- Department of Stem Cell regulation, Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Johji Inazawa
- Department of Molecular Cytogenetics, Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Tetsuya Taga
- Department of Stem Cell regulation, Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
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7
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Skowronki K, Andrews J, Rodenhiser DI, Coomber BL. Genome-wide analysis in human colorectal cancer cells reveals ischemia-mediated expression of motility genes via DNA hypomethylation. PLoS One 2014; 9:e103243. [PMID: 25079072 PMCID: PMC4117527 DOI: 10.1371/journal.pone.0103243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/30/2014] [Indexed: 12/26/2022] Open
Abstract
DNA hypomethylation is an important epigenetic modification found to occur in many different cancer types, leading to the upregulation of previously silenced genes and loss of genomic stability. We previously demonstrated that hypoxia and hypoglycaemia (ischemia), two common micro-environmental changes in solid tumours, decrease DNA methylation through the downregulation of DNMTs in human colorectal cancer cells. Here, we utilized a genome-wide cross-platform approach to identify genes hypomethylated and upregulated by ischemia. Following exposure to hypoxia or hypoglycaemia, methylated DNA from human colorectal cancer cells (HCT116) was immunoprecipitated and analysed with an Affymetrix promoter array. Additionally, RNA was isolated and analysed in parallel with an Affymetrix expression array. Ingenuity pathway analysis software revealed that a significant proportion of the genes hypomethylated and upregulated were involved in cellular movement, including PLAUR and CYR61. A Matrigel invasion assay revealed that indeed HCT116 cells grown in hypoxic or hypoglycaemic conditions have increased mobility capabilities. Confirmation of upregulated expression of cellular movement genes was performed with qPCR. The correlation between ischemia and metastasis is well established in cancer progression, but the molecular mechanisms responsible for this common observation have not been clearly identified. Our novel data suggests that hypoxia and hypoglycaemia may be driving changes in DNA methylation through downregulation of DNMTs. This is the first report to our knowledge that provides an explanation for the increased metastatic potential seen in ischemic cells; i.e. that ischemia could be driving DNA hypomethylation and increasing expression of cellular movement genes.
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Affiliation(s)
- Karolina Skowronki
- Department of Biomedical Sciences; Ontario Veterinary College; University of Guelph; Guelph, ON, Canada
| | - Joseph Andrews
- Departments of Biochemistry, Oncology and Paediatrics; University of Western Ontario; London Regional Cancer Centre and Children’s Health Research Institute; London, ON, Canada
| | - David I. Rodenhiser
- Departments of Biochemistry, Oncology and Paediatrics; University of Western Ontario; London Regional Cancer Centre and Children’s Health Research Institute; London, ON, Canada
| | - Brenda L. Coomber
- Department of Biomedical Sciences; Ontario Veterinary College; University of Guelph; Guelph, ON, Canada
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Nwaobi SE, Lin E, Peramsetty SR, Olsen ML. DNA methylation functions as a critical regulator of Kir4.1 expression during CNS development. Glia 2014; 62:411-27. [PMID: 24415225 DOI: 10.1002/glia.22613] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 10/29/2013] [Accepted: 11/21/2013] [Indexed: 12/22/2022]
Abstract
Kir4.1, a glial-specific K+ channel, is critical for normal CNS development. Studies using both global and glial-specific knockout of Kir4.1 reveal abnormal CNS development with the loss of the channel. Specifically, Kir4.1 knockout animals are characterized by ataxia, severe hypomyelination, and early postnatal death. Additionally, Kir4.1 has emerged as a key player in several CNS diseases. Notably, decreased Kir4.1 protein expression occurs in several human CNS pathologies including CNS ischemic injury, spinal cord injury, epilepsy, ALS, and Alzheimer's disease. Despite the emerging significance of Kir4.1 in normal and pathological conditions, its mechanisms of regulation are unknown. Here, we report the first epigenetic regulation of a K+ channel in the CNS. Robust developmental upregulation of Kir4.1 expression in rats is coincident with reductions in DNA methylation of the Kir4.1 gene, KCNJ10. Chromatin immunoprecipitation reveals a dynamic interaction between KCNJ10 and DNA methyltransferase 1 during development. Finally, demethylation of the KCNJ10 promoter is necessary for transcription. These findings indicate DNA methylation is a key regulator of Kir4.1 transcription. Given the essential role of Kir4.1 in normal CNS development, understanding the regulation of this K+ channel is critical to understanding normal glial biology.
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Affiliation(s)
- Sinifunanya E Nwaobi
- Department of Cell, Developmental and Integrative Biology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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9
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Majumder A, Dhara SK, Swetenburg R, Mithani M, Cao K, Medrzycki M, Fan Y, Stice SL. Inhibition of DNA methyltransferases and histone deacetylases induces astrocytic differentiation of neural progenitors. Stem Cell Res 2013; 11:574-86. [PMID: 23644509 DOI: 10.1016/j.scr.2013.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/06/2013] [Accepted: 03/25/2013] [Indexed: 11/25/2022] Open
Abstract
Understanding how to specify rapid differentiation of human neural progenitor towards enriched non-transformed human astrocyte progenitors will provide a critical cell source to further our understanding of how astrocytes play a pivotal role in neural function and development. Human neural progenitors derived from pluripotent embryonic stem cells and propagated in adherent serum-free cultures provide a fate restricted renewable source for quick production of neural cells; however, such cells are highly refractive to astrocytogenesis and show a strong neurogenic bias, similar to neural progenitors from the early embryonic central nervous system (CNS). We found that several astrocytic genes are hypermethylated in such progenitors potentially preventing generation of astrocytes and leading to the proneuronal fate of these progenitors. However, epigenetic modification by Azacytidine (Aza-C) and Trichostatin A (TSA), with concomitant signaling from BMP2 and LIF in neural progenitor cultures shifts this bias, leading to expression of astrocytic markers as early as 5days of differentiation, with near complete suppression of neuronal differentiation. The resultant cells express major astrocytic markers, are amenable to co-culture with neurons, can be propagated as astrocyte progenitors and are cryopreservable. Although previous reports have generated astrocytes from pluripotent cells, the differentiation required extensive culture or selection based on cell surface antigens. The development of a label free and rapid differentiation process will expedite future derivation of astrocytes from various sources pluripotent cells including, but not limited to, human astrocytes associated with various neurological diseases.
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Affiliation(s)
- Anirban Majumder
- Regenerative Bioscience Center, University of Georgia, 425 River Rd, Athens, GA 30602, USA
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10
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Kumari S, Swaminathan A, Chatterjee S, Senapati P, Boopathi R, Kundu TK. Chromatin organization, epigenetics and differentiation: an evolutionary perspective. Subcell Biochem 2013; 61:3-35. [PMID: 23150244 DOI: 10.1007/978-94-007-4525-4_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Genome packaging is a universal phenomenon from prokaryotes to higher mammals. Genomic constituents and forces have however, travelled a long evolutionary route. Both DNA and protein elements constitute the genome and also aid in its dynamicity. With the evolution of organisms, these have experienced several structural and functional changes. These evolutionary changes were made to meet the challenging scenario of evolving organisms. This review discusses in detail the evolutionary perspective and functionality gain in the phenomena of genome organization and epigenetics.
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Affiliation(s)
- Sujata Kumari
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit (MBGU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur Post, Bangalore, 560064, India
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11
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Nagy C, Turecki G. Sensitive periods in epigenetics: bringing us closer to complex behavioral phenotypes. Epigenomics 2012; 4:445-57. [PMID: 22920183 PMCID: PMC5293543 DOI: 10.2217/epi.12.37] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Genetic studies have attempted to elucidate causal mechanisms for the development of complex disease, but genome-wide associations have been largely unsuccessful in establishing these links. As an alternative link between genes and disease, recent efforts have focused on mechanisms that alter the function of genes without altering the underlying DNA sequence. Known as epigenetic mechanisms, these include DNA methylation, chromatin conformational changes through histone modifications, ncRNAs and, most recently, 5-hydroxymethylcytosine. Although DNA methylation is involved in normal development, aging and gene regulation, altered methylation patterns have been associated with disease. It is generally believed that early life constitutes a period during which there is increased sensitivity to the regulatory effects of epigenetic mechanisms. The purpose of this review is to outline the contribution of epigenetic mechanisms to genomic function, particularly in the development of complex behavioral phenotypes, focusing on the sensitive periods.
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Affiliation(s)
- Corina Nagy
- McGill Group for Suicide Studies, Douglas Hospital University Institute, 6875 Lasalle boul, Montreal, QC, Canada
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12
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Abstract
The importance of adult neurogenesis has only recently been accepted, resulting in a completely new field of investigation within stem cell biology. The regulation and functional significance of adult neurogenesis is currently an area of highly active research. G-protein-coupled receptors (GPCRs) have emerged as potential modulators of adult neurogenesis. GPCRs represent a class of proteins with significant clinical importance, because approximately 30% of all modern therapeutic treatments target these receptors. GPCRs bind to a large class of neurotransmitters and neuromodulators such as norepinephrine, dopamine, and serotonin. Besides their typical role in cellular communication, GPCRs are expressed on adult neural stem cells and their progenitors that relay specific signals to regulate the neurogenic process. This review summarizes the field of adult neurogenesis and its methods and specifies the roles of various GPCRs and their signal transduction pathways that are involved in the regulation of adult neural stem cells and their progenitors. Current evidence supporting adult neurogenesis as a model for self-repair in neuropathologic conditions, adult neural stem cell therapeutic strategies, and potential avenues for GPCR-based therapeutics are also discussed.
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Affiliation(s)
- Van A Doze
- Department of Molecular Cardiology, NB50, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA
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13
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Shimozaki K, Zhang CL, Suh H, Denli AM, Evans RM, Gage FH. SRY-box-containing gene 2 regulation of nuclear receptor tailless (Tlx) transcription in adult neural stem cells. J Biol Chem 2011; 287:5969-78. [PMID: 22194602 DOI: 10.1074/jbc.m111.290403] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Adult neurogenesis is maintained by self-renewable neural stem cells (NSCs). Their activity is regulated by multiple signaling pathways and key transcription factors. However, it has been unclear whether these factors interplay with each other at the molecular level. Here we show that SRY-box-containing gene 2 (Sox2) and nuclear receptor tailless (TLX) form a molecular network in adult NSCs. We observed that both Sox2 and TLX proteins bind to the upstream region of Tlx gene. Sox2 positively regulates Tlx expression, whereas the binding of TLX to its own promoter suppresses its transcriptional activity in luciferase reporter assays. Such TLX-mediated suppression can be antagonized by overexpressing wild-type Sox2 but not a mutant lacking the transcriptional activation domain. Furthermore, through regions involved in DNA-binding activity, Sox2 and TLX physically interact to form a complex on DNAs that contain a consensus binding site for TLX. Finally, depletion of Sox2 revealed the potential negative feedback loop of TLX expression that is antagonized by Sox2 in adult NSCs. These data suggest that Sox2 plays an important role in Tlx transcription in cultured adult NSCs.
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Affiliation(s)
- Koji Shimozaki
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
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14
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Mohamed Ariff I, Mitra A, Basu A. Epigenetic regulation of self-renewal and fate determination in neural stem cells. J Neurosci Res 2011; 90:529-39. [DOI: 10.1002/jnr.22804] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 08/18/2011] [Accepted: 09/02/2011] [Indexed: 01/30/2023]
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15
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Byun CJ, Seo J, Jo SA, Park YJ, Klug M, Rehli M, Park MH, Jo I. DNA methylation of the 5'-untranslated region at +298 and +351 represses BACE1 expression in mouse BV-2 microglial cells. Biochem Biophys Res Commun 2011; 417:387-92. [PMID: 22166205 DOI: 10.1016/j.bbrc.2011.11.123] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 11/29/2011] [Indexed: 01/15/2023]
Abstract
BACE1, which cleaves the amyloid precursor protein, is the rate-limiting enzyme for β-amyloid peptide production, leading to the pathogenesis of Alzheimer's disease (AD). A high plasma level of homocysteine, acting as a potent methyltransferase inhibitor, is assumed to be a risk factor for AD onset. Using the demethylating drug 5-aza-2'-deoxycytidine (5-Aza), we tested whether and how BACE1 expression is regulated in mouse BV-2 microglial cells. 5-Aza increased both BACE1 mRNA and protein levels in a dose-dependent manner. Bisulfite-sequencing analysis revealed that two CpG sites at positions +298 and +351 in the 5'-untranslated region (5'-UTR) of the BACE1 gene were specifically demethylated in BV-2 cells treated with 5-Aza. In silico analysis showed that the +351 site is the STAT3/CTCF-binding site; the function of the +298 site has not been identified. To assess whether these two CpG sites play an important role in 5-Aza-induced transcriptional activation of BACE1, we constructed a BACE1 gene promoter including the 5'-UTR (-1136 to +500) fused to a CpG-free luciferase gene (pCpGL-BACE1) and its mutant pCpGL-BACE1-AA, which has substituted CG dinucleotides at the two CpG sites of pCpGL-BACE1 to AA. Promoter analysis showed a significant decrease (∼30%) in the activity of pCpGL-BACE1-AA compared with that of pCpGL-BACE1. Furthermore, in vitro methylation of these two reporter constructs showed a complete silencing of their promoter activities. Our data demonstrate that BACE1 gene expression is regulated by DNA methylation of at least two CpG sites at positions +298 and +351 in the 5'-UTR in BV-2 microglial cells.
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Georgi SA, Reh TA. Dicer is required for the maintenance of notch signaling and gliogenic competence during mouse retinal development. Dev Neurobiol 2011; 71:1153-69. [PMID: 21542136 PMCID: PMC5373852 DOI: 10.1002/dneu.20899] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
MicroRNAs (miRNAs) are 19-25 nucleotide RNAs that regulate messenger RNA translation and stability. Recently, we performed a conditional knockout (CKO) of the miRNA-processing enzyme Dicer during mouse retinal development and showed an essential role for miRNAs in the transition of retinal progenitors from an early to a late competence state (Georgi and Reh [2010]: J Neurosci 30:4048-4061). Notably, Dicer CKO progenitors failed to express Ascl1 and generated ganglion cells beyond their normal competence window. Because Ascl1 regulates multiple Notch signaling components, we hypothesized that Notch signaling is downregulated in Dicer CKO retinas. We show here that Notch signaling is severely reduced in Dicer CKO retinas, but that retinal progenitors still retain a low level of Notch signaling. By increasing Notch signaling in Dicer CKO progenitors through constitutive expression of the Notch intracellular domain (NICD), we show that transgenic rescue of Notch signaling has little effect on the competence of retinal progenitors or the enhanced generation of ganglion cells, suggesting that loss of Notch signaling is not a major determinant of these phenotypes. Nevertheless, transgenic NICD expression restored horizontal cells, suggesting an interaction between miRNAs and Notch signaling in the development of this cell type. Furthermore, while NICD overexpression leads to robust glial induction in control retinas, NICD overexpression was insufficient to drive Dicer-null retinal progenitors to a glial fate. Surprisingly, the presence of transgenic NICD expression did not prevent the differentiation of some types of retinal neurons, suggesting that Notch inactivation is not an absolute requirement for the initial stages of neuronal differentiation.
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Affiliation(s)
- Sean A Georgi
- Neurobiology and Behavior Program, Department of Biological Structure, School of Medicine, University of Washington, Seattle, USA
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17
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Alonso MM, Diez-Valle R, Manterola L, Rubio A, Liu D, Cortes-Santiago N, Urquiza L, Jauregi P, de Munain AL, Sampron N, Aramburu A, Tejada-Solís S, Vicente C, Odero MD, Bandrés E, García-Foncillas J, Idoate MA, Lang FF, Fueyo J, Gomez-Manzano C. Genetic and epigenetic modifications of Sox2 contribute to the invasive phenotype of malignant gliomas. PLoS One 2011; 6:e26740. [PMID: 22069467 PMCID: PMC3206066 DOI: 10.1371/journal.pone.0026740] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 10/02/2011] [Indexed: 11/18/2022] Open
Abstract
We undertook this study to understand how the transcription factor Sox2 contributes to the malignant phenotype of glioblastoma multiforme (GBM), the most aggressive primary brain tumor. We initially looked for unbalanced genomic rearrangements in the Sox2 locus in 42 GBM samples and found that Sox2 was amplified in 11.5% and overexpressed in all the samples. These results prompted us to further investigate the mechanisms involved in Sox2 overexpression in GBM. We analyzed the methylation status of the Sox2 promoter because high CpG density promoters are associated with key developmental genes. The Sox2 promoter presented a CpG island that was hypomethylated in all the patient samples when compared to normal cell lines. Treatment of Sox2-negative glioma cell lines with 5-azacitidine resulted in the re-expression of Sox2 and in a change in the methylation status of the Sox2 promoter. We further confirmed these results by analyzing data from GBM cases generated by The Cancer Genome Atlas project. We observed Sox2 overexpression (86%; N = 414), Sox2 gene amplification (8.5%; N = 492), and Sox 2 promoter hypomethylation (100%; N = 258), suggesting the relevance of this factor in the malignant phenotype of GBMs. To further explore the role of Sox2, we performed in vitro analysis with brain tumor stem cells (BTSCs) and established glioma cell lines. Downmodulation of Sox2 in BTSCs resulted in the loss of their self-renewal properties. Surprisingly, ectopic expression of Sox2 in established glioma cells was not sufficient to support self-renewal, suggesting that additional factors are required. Furthermore, we observed that ectopic Sox2 expression was sufficient to induce invasion and migration of glioma cells, and knockdown experiments demonstrated that Sox2 was essential for maintaining these properties. Altogether, our data underscore the importance of a pleiotropic role of Sox2 and suggest that it could be used as a therapeutic target in GBM.
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Affiliation(s)
- Marta M. Alonso
- Department of Neuro-oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Department of Oncology, University Hospital of Navarra, Pamplona, Spain
| | - Ricardo Diez-Valle
- Department of Neurosurgery, University Hospital of Navarra, Pamplona, Spain
| | - Lorea Manterola
- Division of Oncology, BioDonostia Institute, San Sebastian, Spain
| | - Angel Rubio
- Department of Biostatistics, Centro de Estudios e Investigaciones Técnicas de Guipuzcoa (CEIT), San Sebastian, Spain
| | - Dan Liu
- Department of Oncology, University Hospital of Navarra, Pamplona, Spain
| | - Nahir Cortes-Santiago
- Department of Neuro-oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Leire Urquiza
- Division of Oncology, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Patricia Jauregi
- Department of Oncology, University Hospital of Navarra, Pamplona, Spain
| | | | - Nicolás Sampron
- Division of Oncology, BioDonostia Institute, San Sebastian, Spain
| | - Ander Aramburu
- Department of Biostatistics, Centro de Estudios e Investigaciones Técnicas de Guipuzcoa (CEIT), San Sebastian, Spain
| | - Sonia Tejada-Solís
- Department of Neurosurgery, University Hospital of Navarra, Pamplona, Spain
| | - Carmen Vicente
- Division of Oncology, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - María D. Odero
- Division of Oncology, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Eva Bandrés
- Department of Oncology, University Hospital of Navarra, Pamplona, Spain
| | | | - Miguel A. Idoate
- Department of Pathology, University Hospital of Navarra, Pamplona, Spain
| | - Frederick F. Lang
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Juan Fueyo
- Department of Neuro-oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Candelaria Gomez-Manzano
- Department of Neuro-oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
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Restrepo A, Smith CA, Agnihotri S, Shekarforoush M, Kongkham PN, Seol HJ, Northcott P, Rutka JT. Epigenetic regulation of glial fibrillary acidic protein by DNA methylation in human malignant gliomas. Neuro Oncol 2010; 13:42-50. [PMID: 21075782 DOI: 10.1093/neuonc/noq145] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Glial fibrillary acidic protein (GFAP) is an intermediate filament expressed in glial cells that stabilizes and maintains the cytoskeleton of normal astrocytes. In glial tumors, GFAP expression is frequently lost with increasing grade of malignancy, suggesting that GFAP is important for maintaining glial cell morphology or regulating astrocytoma cell growth. Most permanent human glioma cell lines are GFAP negative by immunocytochemistry. Given that the GFAP gene is not mutated in human glioma specimens or glioma cell lines, we considered epigenetic mechanisms, such as promoter methylation, as a cause of silencing of GFAP in these tumors. In this study, we treated known GFAP-negative glioma cell lines with 5-aza-2'-deoxycytidine to examine GFAP promoter hypermethylation. Additionally, we performed bisulfite sequencing on primary glioma samples and glioma cell lines and showed an inverse relationship between GFAP promoter methylation status and GFAP expression. Using a gene reporter assay with the GFAP promoter cloned upstream of a luciferase gene, we showed that methylation of the GFAP promoter downregulates the expression of the luciferase gene. Our results suggest that epigenetic silencing of the GFAP gene through DNA methylation of its promoter region may be one mechanism by which GFAP is downregulated in human gliomas and glioma cell lines.
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Affiliation(s)
- Andres Restrepo
- Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumor Research Centre, Program in Cell Biology, Suite 1503, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, Canada M5G 1X8
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Juliandi B, Abematsu M, Nakashima K. Epigenetic regulation in neural stem cell differentiation. Dev Growth Differ 2010; 52:493-504. [DOI: 10.1111/j.1440-169x.2010.01175.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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20
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Rapid quantification of DNA methylation by measuring relative peak heights in direct bisulfite-PCR sequencing traces. J Transl Med 2010; 90:282-90. [PMID: 20010852 DOI: 10.1038/labinvest.2009.132] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Various technologies are currently available to quantify DNA methylation. However, rapid and simple methods for determining the DNA methylation status of CpG sites in genes still remain elusive. In this report, we describe a novel method for the rapid quantification of CpG methylation on the basis of direct bisulfite-PCR sequencing method. According to the principles of bisulfite-PCR, converting unmethylated cytosines to thymine while leaving methylated cytosines unchanged, we regard the CpG site as a SNP and estimate the methylation status of cytosines in the given CG dinucleotides by measuring the ratio of the cytosine peak height to the sum of cytosine and thymine peak heights in automated DNA sequencing traces. Furthermore, we take several effective measures to break through the 'bottleneck' problems that render the routine bisulfite sequencing method unsuitable for quantitative methylation. In comparison with pyrosequencing and bisulfite-cloning sequencing, our method is confirmed to be a simple, high-throughput and cost-effective technology for determining the methylation status of specific genes. Accordingly, this novel method is anticipated to be an efficient and economical alternative tool for rapid quantification of methylation patterns in screening large numbers of clinical samples across multiple genes.
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21
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Meyer MJ, Fleming JM, Ali MA, Pesesky MW, Ginsburg E, Vonderhaar BK. Dynamic regulation of CD24 and the invasive, CD44posCD24neg phenotype in breast cancer cell lines. Breast Cancer Res 2009; 11:R82. [PMID: 19906290 PMCID: PMC2815544 DOI: 10.1186/bcr2449] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/21/2009] [Accepted: 11/11/2009] [Indexed: 03/02/2023] Open
Abstract
Introduction The invasive, mesenchymal phenotype of CD44posCD24neg breast cancer cells has made them a promising target for eliminating the metastatic capacity of primary tumors. It has been previously demonstrated that CD44neg/lowCD24pos breast cancer cells lack the ability to give rise to their invasive CD44posCD24neg counterpart. Here we demonstrate that noninvasive, epithelial-like CD44posCD24pos cells readily give rise to invasive, mesenchymal CD44posCD24neg progeny in vivo and in vitro. This interconversion was found to be dependent upon Activin/Nodal signaling. Methods Breast cancer cell lines were sorted into CD44posCD24pos and CD44posCD24neg populations to evaluate their progeny for the expression of CD44, CD24, and markers of a mesenchymal phenotype. The populations, separated by fluorescence activated cell sorting (FACS) were injected into immunocompromised mice to evaluate their tumorigenicity and invasiveness of the resulting xenografts. Results CD24 expression was dynamically regulated in vitro in all evaluated breast cancer cell lines. Furthermore, a single noninvasive, epithelial-like CD44posCD24pos cell had the ability to give rise to invasive, mesenchymal CD44posCD24neg progeny. Importantly, this interconversion occurred in vivo as CD44posCD24pos cells gave rise to xenografts with locally invasive borders as seen in xenografts initiated with CD44posCD24neg cells. Lastly, the ability of CD44posCD24pos cells to give rise to mesenchymal progeny, and vice versa, was blocked upon ablation of Activin/Nodal signaling. Conclusions Our data demonstrate that the invasive, mesenchymal CD44posCD24neg phenotype is under dynamic control in breast cancer cell lines both in vitro and in vivo. Furthermore, our observations suggest that therapies targeting CD44posCD24neg tumor cells may have limited success in preventing primary tumor metastasis unless Activin/Nodal signaling is arrested.
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Affiliation(s)
- Matthew J Meyer
- Mammary Biology and Tumorigenesis Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Building 37, Room 1106, Bethesda, Maryland 20892-4254, USA.
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22
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Kumagai G, Okada Y, Yamane J, Nagoshi N, Kitamura K, Mukaino M, Tsuji O, Fujiyoshi K, Katoh H, Okada S, Shibata S, Matsuzaki Y, Toh S, Toyama Y, Nakamura M, Okano H. Roles of ES cell-derived gliogenic neural stem/progenitor cells in functional recovery after spinal cord injury. PLoS One 2009; 4:e7706. [PMID: 19893739 PMCID: PMC2768792 DOI: 10.1371/journal.pone.0007706] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 10/09/2009] [Indexed: 01/22/2023] Open
Abstract
Transplantation of neural stem/progenitor cells (NS/PCs) following the sub-acute phase of spinal cord injury (SCI) has been shown to promote functional recovery in rodent models. However, the types of cells most effective for treating SCI have not been clarified. Taking advantage of our recently established neurosphere-based culture system of ES cell-derived NS/PCs, in which primary neurospheres (PNS) and passaged secondary neurospheres (SNS) exhibit neurogenic and gliogenic potentials, respectively, here we examined the distinct effects of transplanting neurogenic and gliogenic NS/PCs on the functional recovery of a mouse model of SCI. ES cell-derived PNS and SNS transplanted 9 days after contusive injury at the Th10 level exhibited neurogenic and gliogenic differentiation tendencies, respectively, similar to those seen in vitro. Interestingly, transplantation of the gliogenic SNS, but not the neurogenic PNS, promoted axonal growth, remyelination, and angiogenesis, and resulted in significant locomotor functional recovery after SCI. These findings suggest that gliogenic NS/PCs are effective for promoting the recovery from SCI, and provide essential insight into the mechanisms through which cellular transplantation leads to functional improvement after SCI.
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Affiliation(s)
- Gentaro Kumagai
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Yohei Okada
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Neurology, Graduate School of Medicine, Nagoya University, Nagoya, Japan
- Kanrinmaru Project, Keio University School of Medicine, Tokyo, Japan
| | - Junichi Yamane
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Narihito Nagoshi
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Kazuya Kitamura
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masahiko Mukaino
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Osahiko Tsuji
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Kanehiro Fujiyoshi
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hiroyuki Katoh
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Seiji Okada
- Department of Research Super Star Program Stem Cell Unit, Graduate School of Medical Science, Kyusyu University, Fukuoka, Japan
| | - Shinsuke Shibata
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Yumi Matsuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Satoshi Toh
- Department of Orthopedic Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Yoshiaki Toyama
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masaya Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
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23
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MicroRNAs in adult and embryonic neurogenesis. Neuromolecular Med 2009; 11:141-52. [PMID: 19598002 DOI: 10.1007/s12017-009-8077-y] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Accepted: 06/30/2009] [Indexed: 12/22/2022]
Abstract
Neurogenesis is defined as a process that includes the proliferation of neural stem/progenitor cells (NPCs) and the differentiation of these cells into new neurons that integrate into the existing neuronal circuitry. MicroRNAs (miRNAs) are a recently discovered class of small non-protein coding RNA molecules implicated in a wide range of diverse gene regulatory mechanisms. More and more data demonstrate that numerous miRNAs are expressed in a spatially and temporally controlled manners in the nervous system, which suggests that miRNAs have important roles in the gene regulatory networks involved in both brain development and adult neural plasticity. This review summarizes the roles of miRNAs-mediated gene regulation in the nervous system with focus on neurogenesis in both embryonic and adult brains.
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Hutnick LK, Golshani P, Namihira M, Xue Z, Matynia A, Yang XW, Silva AJ, Schweizer FE, Fan G. DNA hypomethylation restricted to the murine forebrain induces cortical degeneration and impairs postnatal neuronal maturation. Hum Mol Genet 2009; 18:2875-88. [PMID: 19433415 DOI: 10.1093/hmg/ddp222] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
DNA methylation is a major epigenetic factor regulating genome reprogramming, cell differentiation and developmental gene expression. To understand the role of DNA methylation in central nervous system (CNS) neurons, we generated conditional Dnmt1 mutant mice that possess approximately 90% hypomethylated cortical and hippocampal cells in the dorsal forebrain from E13.5 on. The mutant mice were viable with a normal lifespan, but displayed severe neuronal cell death between E14.5 and three weeks postnatally. Accompanied with the striking cortical and hippocampal degeneration, adult mutant mice exhibited neurobehavioral defects in learning and memory in adulthood. Unexpectedly, a fraction of Dnmt1(-/-) cortical neurons survived throughout postnatal development, so that the residual cortex in mutant mice contained 20-30% of hypomethylated neurons across the lifespan. Hypomethylated excitatory neurons exhibited multiple defects in postnatal maturation including abnormal dendritic arborization and impaired neuronal excitability. The mutant phenotypes are coupled with deregulation of those genes involved in neuronal layer-specification, cell death and the function of ion channels. Our results suggest that DNA methylation, through its role in modulating neuronal gene expression, plays multiple roles in regulating cell survival and neuronal maturation in the CNS.
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Affiliation(s)
- Leah K Hutnick
- Department of Human Genetics, David Geffen School of Medicine, University of California at Los Angeles, 695 Charles Young Drive South, Los Angeles, CA 90095, USA
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25
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Committed neuronal precursors confer astrocytic potential on residual neural precursor cells. Dev Cell 2009; 16:245-55. [PMID: 19217426 DOI: 10.1016/j.devcel.2008.12.014] [Citation(s) in RCA: 244] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 12/01/2008] [Accepted: 12/30/2008] [Indexed: 12/31/2022]
Abstract
During midgestation, mammalian neural precursor cells (NPCs) differentiate only into neurons. Generation of astrocytes is prevented at this stage, because astrocyte-specific gene promoters are methylated. How the subsequent switch from suppression to expression of astrocytic genes occurs is unknown. We show in this study that Notch ligands are expressed on committed neuronal precursors and young neurons in mid-gestational telencephalon, and that neighboring Notch-activated NPCs acquire the potential to become astrocytes. Activation of the Notch signaling pathway in midgestational NPCs induces expression of the transcription factor nuclear factor I, which binds to astrocytic gene promoters, resulting in demethylation of astrocyte-specific genes. These findings provide a mechanistic explanation for why neurons come first: committed neuronal precursors and young neurons potentiate remaining NPCs to differentiate into the next cell lineage, astrocytes.
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Abstract
Two critical properties of stem cells are self-renewal and multipotency. The maintenance of their "stemness" state and commitment to differentiation are therefore tightly controlled by intricate molecular networks. Epigenetic mechanisms, including DNA methylation, chromatin remodeling and the noncoding RNA-mediated process, have profound regulatory roles in mammalian gene expression. Recent studies have shown that epigenetic regulators are key players in stem cell biology and their dysfunction can result in human diseases such as cancer and neurodevelopmental disorders. Here, we review the recent evidences that advance our knowledge in epigenetic regulations of mammalian stem cells, with focus on embryonic stem cells and neural stem cells.
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Affiliation(s)
- Xuekun Li
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, USA
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27
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Lederer CW, Santama N. Neural stem cells: mechanisms of fate specification and nuclear reprogramming in regenerative medicine. Biotechnol J 2009; 3:1521-38. [PMID: 19072908 DOI: 10.1002/biot.200800193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recently, intense interest in the potential use of neural stem cells (NSC) in the clinical therapy of brain disease and injury has resulted in rapid progress in research on the properties of NSC, their innate and directed differentiation potential and the induced reprogramming of differentiated somatic cells to revert to a pluripotent NSC-like state. The aim of this review is to give an overview of our current operational definitions of the NSC lineage, the growing understanding of extrinsic and intrinsic mechanisms, including heritable but reversible epigenetic chromatin modifications that regulate the maintenance and differentiation of NSC in vivo, and to emphasize ground-breaking efforts of cellular reprogramming with the view to generating patient-specific stem cells for cell replacement therapy. This is set against a summary of current practical procedures for the isolation, research and application of NSC, and of the state of the art in NSC-based regenerative medicine of the nervous system. Both provide the backdrop for the translation of recent findings into innovative clinical applications, with the hope of increasing the safety, efficiency and ethical acceptability of NSC-based therapies in the near future.
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Wen S, Li H, Liu J. Dynamic signaling for neural stem cell fate determination. Cell Adh Migr 2009; 3:107-17. [PMID: 19262166 DOI: 10.4161/cam.3.1.7602] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Central nervous system (CNS) development starts from neural stem cells (NSCs) which ultimately give rise to the three major cell types (neurons, oligodendrocytes and astrocytes) of the CNS. NSCs are specified in space- and time-related fashions, becoming spatially heterogeneous and generating a progressively restricted repertoire of cell types. Mammalian NSCs produce different cell types at different time points during development under the influence of multiple signaling pathways. These pathways act in a dynamic web mode to determine the fate of NSCs via modulating the expression and activity of distinct set of transcription factors which in turn trigger the transcription of neural fate-associated genes. This review thus introduces the major signal pathways, transcription factors and their cross-talks and coordinative interactions in NSC fate determination.
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Affiliation(s)
- Shu Wen
- Department of Cell Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
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Wen S, Li H, Liu J. Epigenetic background of neuronal fate determination. Prog Neurobiol 2008; 87:98-117. [PMID: 19007844 DOI: 10.1016/j.pneurobio.2008.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 09/03/2008] [Accepted: 10/15/2008] [Indexed: 01/07/2023]
Abstract
The development of the central nervous system (CNS) starts from neural stem cells (NSCs). During this process, NSCs are specified in space- and time-related fashions, becoming spatially heterogeneous and generating a progressively restricted repertoire of cell types: neurons, astrocytes and oligodendrocytes. The processes of neurodevelopment are determined reciprocally by intrinsic and external factors which interface to program and re-program the profiling of fate-determination gene expression. Multiple signaling pathways act in a dynamic web mode to determine the fate of NSCs through modulating the activity of a distinct set of transcription factors which in turn trigger the transcription of neural fate-determination genes. Accumulating evidence reveals that during CNS development, multiple epigenetic factors regulate the activities of extracellular signaling and corresponding transcription factors in a coordinative manner, leading to the formation of a system with sophisticated structure and magic functions. This review aims to introduce recent advances in the epigenetic background of neural cell fate determination.
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Affiliation(s)
- Shu Wen
- Department of Cell Biology, College of Basic Medical Sciences, Dalian Medical University, 116044 Dalian, Liaoning, PR China
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30
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Namihira M, Kohyama J, Abematsu M, Nakashima K. Epigenetic mechanisms regulating fate specification of neural stem cells. Philos Trans R Soc Lond B Biol Sci 2008; 363:2099-109. [PMID: 18375376 DOI: 10.1098/rstb.2008.2262] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neural stem cells (NSCs) possess the ability to self-renew and to differentiate along neuronal and glial lineages. These processes are defined by the dynamic interplay between extracellular cues including cytokine signalling and intracellular programmes such as epigenetic modification. There is increasing evidence that epigenetic mechanisms involving, for example, changes in DNA methylation, histone modification and non-coding RNA expression are closely associated with fate specification of NSCs. These epigenetic alterations could provide coordinated systems for regulating gene expression at each step of neural cell differentiation. Here we review the roles of epigenetics in neural fate specification in the mammalian central nervous system.
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Affiliation(s)
- Masakazu Namihira
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma 630-0101, Japan
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Okada Y, Matsumoto A, Shimazaki T, Enoki R, Koizumi A, Ishii S, Itoyama Y, Sobue G, Okano H. Spatiotemporal recapitulation of central nervous system development by murine embryonic stem cell-derived neural stem/progenitor cells. Stem Cells 2008; 26:3086-98. [PMID: 18757299 DOI: 10.1634/stemcells.2008-0293] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Neural stem/progenitor cells (NS/PCs) can generate a wide variety of neural cells. However, their fates are generally restricted, depending on the time and location of NS/PC origin. Here we demonstrate that we can recapitulate the spatiotemporal regulation of central nervous system (CNS) development in vitro by using a neurosphere-based culture system of embryonic stem (ES) cell-derived NS/PCs. This ES cell-derived neurosphere system enables the efficient derivation of highly neurogenic fibroblast growth factor-responsive NS/PCs with early temporal identities and high cell-fate plasticity. Over repeated passages, these NS/PCs exhibit temporal progression, becoming epidermal growth factor-responsive gliogenic NS/PCs with late temporal identities; this change is accompanied by an alteration in the epigenetic status of the glial fibrillary acidic protein promoter, similar to that observed in the developing brain. Moreover, the rostrocaudal and dorsoventral spatial identities of the NS/PCs can be successfully regulated by sequential administration of several morphogens. These NS/PCs can differentiate into early-born projection neurons, including cholinergic, catecholaminergic, serotonergic, and motor neurons, that exhibit action potentials in vitro. Finally, these NS/PCs differentiate into neurons that form synaptic contacts with host neurons after their transplantation into wild-type and disease model animals. Thus, this culture system can be used to obtain specific neurons from ES cells, is a simple and powerful tool for investigating the underlying mechanisms of CNS development, and is applicable to regenerative treatment for neurological disorders.
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Affiliation(s)
- Yohei Okada
- Department of Physiology, Keio University, School of Medicine, Shinjuku-ku, Tokyo, Japan
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32
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Sikorska M, Sandhu JK, Deb-Rinker P, Jezierski A, Leblanc J, Charlebois C, Ribecco-Lutkiewicz M, Bani-Yaghoub M, Walker PR. Epigenetic modifications of SOX2 enhancers, SRR1 and SRR2, correlate with in vitro neural differentiation. J Neurosci Res 2008; 86:1680-93. [PMID: 18293417 DOI: 10.1002/jnr.21635] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
SOX2 is a key neurodevelopmental gene involved in maintaining the pluripotency of stem cells and proliferation of neural progenitors and astroglia. Two evolutionally conserved enhancers, SRR1 and SRR2, are involved in controlling SOX2 expression during neurodevelopment; however, the molecular mechanisms regulating their activity are not known. We have examined DNA methylation and histone H3 acetylation at both enhancers in NT2-D1 progenitors, neurons and astrocytes, to establish the role of epigenetic mechanisms in cell-type-specific SOX2 expression. This study showed that 1) unmethylated DNA and acetylated histones at both enhancers correlated with a high level of SOX2 expression in proliferating neural progenitors and 2) reversible modifications of the SRR1 element were observed during gene reexpression in astrocytes, whereas permanent epigenetic marks on the SRR2 enhancer were seen in neurons where the gene was silenced. Taken together, these results are clear illustrations of cell-type-specific epigenomes and suggest mechanisms by which they may be created and maintained.
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Affiliation(s)
- Marianna Sikorska
- Neurogenesis and Brain Repair Group, Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario, Canada.
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Novikova SI, He F, Bai J, Cutrufello NJ, Lidow MS, Undieh AS. Maternal cocaine administration in mice alters DNA methylation and gene expression in hippocampal neurons of neonatal and prepubertal offspring. PLoS One 2008; 3:e1919. [PMID: 18382688 PMCID: PMC2271055 DOI: 10.1371/journal.pone.0001919] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Accepted: 02/11/2008] [Indexed: 02/03/2023] Open
Abstract
Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8–19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI2 microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression analysis, were evaluated in hippocampal pyramidal neurons excised by laser capture microdissection. Following maternal cocaine exposure, global DNA methylation was significantly decreased at P3 and increased at P30. Among the 492 CGIs whose methylation was significantly altered by cocaine at P3, 34% were hypermethylated while 66% were hypomethylated. Several of these CGIs contained promoter regions for genes implicated in crucial cellular functions. Endogenous expression of selected genes linked to the abnormally methylated CGIs was correspondingly decreased or increased by as much as 4–19-fold. By P30, some of the cocaine-associated effects at P3 endured, reversed to opposite directions, or disappeared. Further, additional sets of abnormally methylated targets emerged at P30 that were not observed at P3. Taken together, these observations indicate that maternal cocaine exposure during the second and third trimesters of gestation could produce potentially profound structural and functional modifications in the epigenomic programs of neonatal and prepubertal mice.
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Affiliation(s)
- Svetlana I. Novikova
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, Philadelphia, Pennsylvania, United States of America
| | - Fang He
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Jie Bai
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Nicholas J. Cutrufello
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Michael S. Lidow
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Ashiwel S. Undieh
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, Philadelphia, Pennsylvania, United States of America
- * To whom correspondence should be addressed. E-mail:
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Malup TK, Kobzev VF, Zhdanova LG, Slobodyanyuk SY, Sviridov SM. Methylation of CpG dinucleotides in the promoter region of the gene encoding the S100b protein in BALB/cLac mice. DOKL BIOCHEM BIOPHYS 2008; 412:1-3. [PMID: 17506341 DOI: 10.1134/s1607672907010012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- T K Malup
- Institute of Cytology and Genetics, Siberian Division, Russian Academy of Sciences, pr. Akademika Lavrent'eva 10, Novosibirsk 630090, Russia
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Allen ND. Temporal and epigenetic regulation of neurodevelopmental plasticity. Philos Trans R Soc Lond B Biol Sci 2008; 363:23-38. [PMID: 17311782 PMCID: PMC2605484 DOI: 10.1098/rstb.2006.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The anticipated therapeutic uses of neural stem cells depend on their ability to retain a certain level of developmental plasticity. In particular, cells must respond to developmental manipulations designed to specify precise neural fates. Studies in vivo and in vitro have shown that the developmental potential of neural progenitor cells changes and becomes progressively restricted with time. For in vitro cultured neural progenitors, it is those derived from embryonic stem cells that exhibit the greatest developmental potential. It is clear that both extrinsic and intrinsic mechanisms determine the developmental potential of neural progenitors and that epigenetic, or chromatin structural, changes regulate and coordinate hierarchical changes in fate-determining gene expression. Here, we review the temporal changes in developmental plasticity of neural progenitor cells and discuss the epigenetic mechanisms that underpin these changes. We propose that understanding the processes of epigenetic programming within the neural lineage is likely to lead to the development of more rationale strategies for cell reprogramming that may be used to expand the developmental potential of otherwise restricted progenitor populations.
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Affiliation(s)
- Nicholas D Allen
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3US, UK.
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Lee G, Kim H, Elkabetz Y, Al Shamy G, Panagiotakos G, Barberi T, Tabar V, Studer L. Isolation and directed differentiation of neural crest stem cells derived from human embryonic stem cells. Nat Biotechnol 2007; 25:1468-75. [PMID: 18037878 DOI: 10.1038/nbt1365] [Citation(s) in RCA: 397] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 11/08/2007] [Indexed: 02/07/2023]
Abstract
Vertebrate neural crest development depends on pluripotent, migratory precursor cells. Although avian and murine neural crest stem (NCS) cells have been identified, the isolation of human NCS cells has remained elusive. Here we report the derivation of NCS cells from human embryonic stem cells at the neural rosette stage. We show that NCS cells plated at clonal density give rise to multiple neural crest lineages. The human NCS cells can be propagated in vitro and directed toward peripheral nervous system lineages (peripheral neurons, Schwann cells) and mesenchymal lineages (smooth muscle, adipogenic, osteogenic and chondrogenic cells). Transplantation of human NCS cells into the developing chick embryo and adult mouse hosts demonstrates survival, migration and differentiation compatible with neural crest identity. The availability of unlimited numbers of human NCS cells offers new opportunities for studies of neural crest development and for efforts to model and treat neural crest-related disorders.
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Affiliation(s)
- Gabsang Lee
- Developmental Biology Program, Sloan-Kettering Institute, 1275 York Ave., New York, New York 10021, USA
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Nguyen S, Meletis K, Fu D, Jhaveri S, Jaenisch R. Ablation of de novo DNA methyltransferase Dnmt3a in the nervous system leads to neuromuscular defects and shortened lifespan. Dev Dyn 2007; 236:1663-76. [PMID: 17477386 DOI: 10.1002/dvdy.21176] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
DNA methylation is an epigenetic mechanism involved in gene regulation and implicated in the functioning of the nervous system. The de novo DNA methyltransferase Dnmt3a is expressed in neurons, but its specific role has not been clarified. Dnmt3a is activated around embryonic day 10.5 in mouse neuronal precursor cells and remains active in postmitotic neurons in the adult. We assessed the role of neuronal Dnmt3a by conditional gene targeting. Mice lacking functional Dnmt3a in the nervous system were born healthy, but degenerated in adulthood and died prematurely. Mutant mice were hypoactive, walked abnormally, and underperformed on tests of neuromuscular function and motor coordination. Loss of Dnmt3a also led to fewer motor neurons in the hypoglossal nucleus and more fragmented endplates in neuromuscular junctions of the diaphragm muscle. Our results implicate a role for Dnmt3a in the neuromuscular control of motor movement.
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Affiliation(s)
- Suzanne Nguyen
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA
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