1
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Pereira A, Diwakar J, Masserdotti G, Beşkardeş S, Simon T, So Y, Martín-Loarte L, Bergemann F, Vasan L, Schauer T, Danese A, Bocchi R, Colomé-Tatché M, Schuurmans C, Philpott A, Straub T, Bonev B, Götz M. Direct neuronal reprogramming of mouse astrocytes is associated with multiscale epigenome remodeling and requires Yy1. Nat Neurosci 2024; 27:1260-1273. [PMID: 38956165 PMCID: PMC11239498 DOI: 10.1038/s41593-024-01677-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 05/10/2024] [Indexed: 07/04/2024]
Abstract
Direct neuronal reprogramming is a promising approach to regenerate neurons from local glial cells. However, mechanisms of epigenome remodeling and co-factors facilitating this process are unclear. In this study, we combined single-cell multiomics with genome-wide profiling of three-dimensional nuclear architecture and DNA methylation in mouse astrocyte-to-neuron reprogramming mediated by Neurogenin2 (Ngn2) and its phosphorylation-resistant form (PmutNgn2), respectively. We show that Ngn2 drives multilayered chromatin remodeling at dynamic enhancer-gene interaction sites. PmutNgn2 leads to higher reprogramming efficiency and enhances epigenetic remodeling associated with neuronal maturation. However, the differences in binding sites or downstream gene activation cannot fully explain this effect. Instead, we identified Yy1, a transcriptional co-factor recruited by direct interaction with Ngn2 to its target sites. Upon deletion of Yy1, activation of neuronal enhancers, genes and ultimately reprogramming are impaired without affecting Ngn2 binding. Thus, our work highlights the key role of interactors of proneural factors in direct neuronal reprogramming.
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Affiliation(s)
- Allwyn Pereira
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
- Nantes Université, CHU Nantes, INSERM, TaRGeT - Translational Research in Gene Therapy, UMR 1089, Nantes, France
| | - Jeisimhan Diwakar
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Helmholtz Pioneer Campus, Helmholtz Center Munich, Neuherberg, Germany
| | - Giacomo Masserdotti
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
| | - Sude Beşkardeş
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Helmholtz Pioneer Campus, Helmholtz Center Munich, Neuherberg, Germany
| | - Tatiana Simon
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
| | - Younju So
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
| | - Lucía Martín-Loarte
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
| | - Franziska Bergemann
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
| | - Lakshmy Vasan
- Biological Science Platform, Sunnybrook Research Institute; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Tamas Schauer
- Biomedical Center Munich (BMC), Bioinformatic Core Facility, Faculty of Medicine, LMU Munich, Planegg, Germany
- Institute of Stem Cells and Epigenetics, Helmholtz Center Munich, Neuherberg, Germany
| | - Anna Danese
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
| | - Riccardo Bocchi
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | - Maria Colomé-Tatché
- Institute of Computational Biology, Helmholtz Center Munich, Neuherberg, Germany
- Biomedical Center Munich (BMC), Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg, Germany
| | - Carol Schuurmans
- Biological Science Platform, Sunnybrook Research Institute; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Anna Philpott
- Wellcome-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Tobias Straub
- Biological Science Platform, Sunnybrook Research Institute; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Boyan Bonev
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany.
- Helmholtz Pioneer Campus, Helmholtz Center Munich, Neuherberg, Germany.
| | - Magdalena Götz
- Biomedical Center Munich (BMC), Physiological Genomics, LMU Munich, Planegg, Germany.
- Institute of Stem Cell Research, Helmholtz Center Munich, BMC LMU Munich, Planegg, Germany.
- Excellence Cluster of Systems Neurology (SYNERGY), Munich, Germany.
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2
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Liang S, Zhou J, Yu X, Lu S, Liu R. Neuronal conversion from glia to replenish the lost neurons. Neural Regen Res 2024; 19:1446-1453. [PMID: 38051886 PMCID: PMC10883502 DOI: 10.4103/1673-5374.386400] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 08/16/2023] [Indexed: 12/07/2023] Open
Abstract
ABSTRACT Neuronal injury, aging, and cerebrovascular and neurodegenerative diseases such as cerebral infarction, Alzheimer's disease, Parkinson's disease, frontotemporal dementia, amyotrophic lateral sclerosis, and Huntington's disease are characterized by significant neuronal loss. Unfortunately, the neurons of most mammals including humans do not possess the ability to self-regenerate. Replenishment of lost neurons becomes an appealing therapeutic strategy to reverse the disease phenotype. Transplantation of pluripotent neural stem cells can supplement the missing neurons in the brain, but it carries the risk of causing gene mutation, tumorigenesis, severe inflammation, and obstructive hydrocephalus induced by brain edema. Conversion of neural or non-neural lineage cells into functional neurons is a promising strategy for the diseases involving neuron loss, which may overcome the above-mentioned disadvantages of neural stem cell therapy. Thus far, many strategies to transform astrocytes, fibroblasts, microglia, Müller glia, NG2 cells, and other glial cells to mature and functional neurons, or for the conversion between neuronal subtypes have been developed through the regulation of transcription factors, polypyrimidine tract binding protein 1 (PTBP1), and small chemical molecules or are based on a combination of several factors and the location in the central nervous system. However, some recent papers did not obtain expected results, and discrepancies exist. Therefore, in this review, we discuss the history of neuronal transdifferentiation, summarize the strategies for neuronal replenishment and conversion from glia, especially astrocytes, and point out that biosafety, new strategies, and the accurate origin of the truly converted neurons in vivo should be focused upon in future studies. It also arises the attention of replenishing the lost neurons from glia by gene therapies such as up-regulation of some transcription factors or down-regulation of PTBP1 or drug interference therapies.
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Affiliation(s)
- Shiyu Liang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Jing Zhou
- Department of Geriatric Rehabilitation, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Xiaolin Yu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Shuai Lu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Ruitian Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
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3
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Sonsalla G, Malpartida AB, Riedemann T, Gusic M, Rusha E, Bulli G, Najas S, Janjic A, Hersbach BA, Smialowski P, Drukker M, Enard W, Prehn JHM, Prokisch H, Götz M, Masserdotti G. Direct neuronal reprogramming of NDUFS4 patient cells identifies the unfolded protein response as a novel general reprogramming hurdle. Neuron 2024; 112:1117-1132.e9. [PMID: 38266647 PMCID: PMC10994141 DOI: 10.1016/j.neuron.2023.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/12/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024]
Abstract
Mitochondria account for essential cellular pathways, from ATP production to nucleotide metabolism, and their deficits lead to neurological disorders and contribute to the onset of age-related diseases. Direct neuronal reprogramming aims at replacing neurons lost in such conditions, but very little is known about the impact of mitochondrial dysfunction on the direct reprogramming of human cells. Here, we explore the effects of mitochondrial dysfunction on the neuronal reprogramming of induced pluripotent stem cell (iPSC)-derived astrocytes carrying mutations in the NDUFS4 gene, important for Complex I and associated with Leigh syndrome. This led to the identification of the unfolded protein response as a major hurdle in the direct neuronal conversion of not only astrocytes and fibroblasts from patients but also control human astrocytes and fibroblasts. Its transient inhibition potently improves reprogramming by influencing the mitochondria-endoplasmic-reticulum-stress-mediated pathways. Taken together, disease modeling using patient cells unraveled novel general hurdles and ways to overcome these in human astrocyte-to-neuron reprogramming.
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Affiliation(s)
- Giovanna Sonsalla
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Graduate School of Systemic Neurosciences, BMC, LMU Munich, Planegg-Martinsried 82152 Germany
| | - Ana Belen Malpartida
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; International Max Planck Research School (IMPRS) for Molecular Life Sciences, Planegg-Martinsried 82152, Germany
| | - Therese Riedemann
- Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - Mirjana Gusic
- Institute of Neurogenomics, Helmholtz Zentrum München, Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Ejona Rusha
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany
| | - Giorgia Bulli
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Graduate School of Systemic Neurosciences, BMC, LMU Munich, Planegg-Martinsried 82152 Germany
| | - Sonia Najas
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany
| | - Aleks Janjic
- Anthropology and Human Genomics, Faculty of Biology, LMU Munich, Planegg-Martinsried 82152, Germany
| | - Bob A Hersbach
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Graduate School of Systemic Neurosciences, BMC, LMU Munich, Planegg-Martinsried 82152 Germany
| | - Pawel Smialowski
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Biomedical Center Munich, Bioinformatic Core Facility, LMU Munich, Planegg-Martinsried 82152, Germany
| | - Micha Drukker
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Gorlaeus Building, 2333 CC RA, Leiden, the Netherlands
| | - Wolfgang Enard
- Anthropology and Human Genomics, Faculty of Biology, LMU Munich, Planegg-Martinsried 82152, Germany
| | - Jochen H M Prehn
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Holger Prokisch
- Institute of Neurogenomics, Helmholtz Zentrum München, Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany; Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Magdalena Götz
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany; Excellence Cluster of Systems Neurology (SYNERGY), Munich, Germany.
| | - Giacomo Masserdotti
- Institute for Stem Cell Research, Helmholtz Center Munich, Neuherberg 85764, Germany; Biomedical Center Munich, Physiological Genomics, LMU Munich, Planegg-Martinsried 82152, Germany.
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4
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Pushchina EV, Kapustyanov IA, Kluka GG. Adult Neurogenesis of Teleost Fish Determines High Neuronal Plasticity and Regeneration. Int J Mol Sci 2024; 25:3658. [PMID: 38612470 PMCID: PMC11012045 DOI: 10.3390/ijms25073658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/28/2024] [Accepted: 03/07/2024] [Indexed: 04/14/2024] Open
Abstract
Studying the properties of neural stem progenitor cells (NSPCs) in a fish model will provide new information about the organization of neurogenic niches containing embryonic and adult neural stem cells, reflecting their development, origin cell lines and proliferative dynamics. Currently, the molecular signatures of these populations in homeostasis and repair in the vertebrate forebrain are being intensively studied. Outside the telencephalon, the regenerative plasticity of NSPCs and their biological significance have not yet been practically studied. The impressive capacity of juvenile salmon to regenerate brain suggests that most NSPCs are likely multipotent, as they are capable of replacing virtually all cell lineages lost during injury, including neuroepithelial cells, radial glia, oligodendrocytes, and neurons. However, the unique regenerative profile of individual cell phenotypes in the diverse niches of brain stem cells remains unclear. Various types of neuronal precursors, as previously shown, are contained in sufficient numbers in different parts of the brain in juvenile Pacific salmon. This review article aims to provide an update on NSPCs in the brain of common models of zebrafish and other fish species, including Pacific salmon, and the involvement of these cells in homeostatic brain growth as well as reparative processes during the postraumatic period. Additionally, new data are presented on the participation of astrocytic glia in the functioning of neural circuits and animal behavior. Thus, from a molecular aspect, zebrafish radial glia cells are seen to be similar to mammalian astrocytes, and can therefore also be referred to as astroglia. However, a question exists as to if zebrafish astroglia cells interact functionally with neurons, in a similar way to their mammalian counterparts. Future studies of this fish will complement those on rodents and provide important information about the cellular and physiological processes underlying astroglial function that modulate neural activity and behavior in animals.
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Affiliation(s)
- Evgeniya Vladislavovna Pushchina
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far East Branch, Russian Academy of Sciences, 690041 Vladivostok, Russia; (I.A.K.); (G.G.K.)
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5
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Wei X, Tang J, Lin C, Jiang X. Review: Non-canonical role of Drosha ribonuclease III. Int J Biol Macromol 2023; 253:127202. [PMID: 37793530 DOI: 10.1016/j.ijbiomac.2023.127202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 09/28/2023] [Accepted: 09/30/2023] [Indexed: 10/06/2023]
Abstract
The typical function of Drosha is participating in cleaving pri-miRNA, the initial step of miRNA biogenesis, in the nucleus. Since Drosha has a double-stranded RNA-binding domain and two RNase III domains, when it binds and/or cleaves other RNA species other than pri-miRNA, Drosha is able to induce a variety of novel biological effects. Moreover, by interacting with other protein, Drosha is able to modify the function of other protein complexes. Recently, diverse non-classical functions of Drosha have been demonstrated, such as promoting DNA damage repair, transcriptional activation and inhibition, pre-mRNA splicing regulation, mRNA destabilization, and virus-host interaction. In this review, we describe these newly discovered functions of Drosha in order to present a panoramic picture of the novel biological processes that Drosha is involved in.
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Affiliation(s)
- Xuanshuo Wei
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Jin Tang
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Chuwen Lin
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Xuan Jiang
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China.
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6
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Frith TJR, Briscoe J, Boezio GLM. From signalling to form: the coordination of neural tube patterning. Curr Top Dev Biol 2023; 159:168-231. [PMID: 38729676 DOI: 10.1016/bs.ctdb.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
The development of the vertebrate spinal cord involves the formation of the neural tube and the generation of multiple distinct cell types. The process starts during gastrulation, combining axial elongation with specification of neural cells and the formation of the neuroepithelium. Tissue movements produce the neural tube which is then exposed to signals that provide patterning information to neural progenitors. The intracellular response to these signals, via a gene regulatory network, governs the spatial and temporal differentiation of progenitors into specific cell types, facilitating the assembly of functional neuronal circuits. The interplay between the gene regulatory network, cell movement, and tissue mechanics generates the conserved neural tube pattern observed across species. In this review we offer an overview of the molecular and cellular processes governing the formation and patterning of the neural tube, highlighting how the remarkable complexity and precision of vertebrate nervous system arises. We argue that a multidisciplinary and multiscale understanding of the neural tube development, paired with the study of species-specific strategies, will be crucial to tackle the open questions.
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Affiliation(s)
| | - James Briscoe
- The Francis Crick Institute, London, United Kingdom.
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7
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Pluta AJ, Studniarek C, Murphy S, Norbury CJ. Cyclin-dependent kinases: Masters of the eukaryotic universe. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 15:e1816. [PMID: 37718413 PMCID: PMC10909489 DOI: 10.1002/wrna.1816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/21/2023] [Accepted: 08/03/2023] [Indexed: 09/19/2023]
Abstract
A family of structurally related cyclin-dependent protein kinases (CDKs) drives many aspects of eukaryotic cell function. Much of the literature in this area has considered individual members of this family to act primarily either as regulators of the cell cycle, the context in which CDKs were first discovered, or as regulators of transcription. Until recently, CDK7 was the only clear example of a CDK that functions in both processes. However, new data points to several "cell-cycle" CDKs having important roles in transcription and some "transcriptional" CDKs having cell cycle-related targets. For example, novel functions in transcription have been demonstrated for the archetypal cell cycle regulator CDK1. The increasing evidence of the overlap between these two CDK types suggests that they might play a critical role in coordinating the two processes. Here we review the canonical functions of cell-cycle and transcriptional CDKs, and provide an update on how these kinases collaborate to perform important cellular functions. We also provide a brief overview of how dysregulation of CDKs contributes to carcinogenesis, and possible treatment avenues. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Processing > 3' End Processing RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | | | - Shona Murphy
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Chris J. Norbury
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
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8
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Kukreja K, Patel N, Megason SG, Klein AM. Global decoupling of cell differentiation from cell division in early embryo development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.29.551123. [PMID: 37546736 PMCID: PMC10402169 DOI: 10.1101/2023.07.29.551123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
As tissues develop, cells divide and differentiate concurrently. Conflicting evidence shows that cell division is either dispensable or required for formation of cell types. To determine the role of cell division in differentiation, we arrested the cell cycle in zebrafish embryos using two independent approaches and profiled them at single-cell resolution. We show that cell division is dispensable for differentiation of all embryonic tissues during initial cell type differentiation from early gastrulation to the end of segmentation. In the absence of cell division, differentiation slows down in some cell types, and cells exhibit global stress responses. While differentiation is robust to blocking cell division, the proportions of cells across cell states are not. This work simplifies our understanding of the role of cell division in development and showcases the utility of combining embryo-wide perturbations with single-cell RNA sequencing to uncover the role of common biological processes across multiple tissues.
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Affiliation(s)
- Kalki Kukreja
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Nikit Patel
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Sean G Megason
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Allon M Klein
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
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9
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Zabihi M, Lotfi R, Yousefi AM, Bashash D. Cyclins and cyclin-dependent kinases: from biology to tumorigenesis and therapeutic opportunities. J Cancer Res Clin Oncol 2023; 149:1585-1606. [PMID: 35781526 DOI: 10.1007/s00432-022-04135-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/13/2022] [Indexed: 12/20/2022]
Abstract
The discussion on cell proliferation cannot be continued without taking a look at the cell cycle regulatory machinery. Cyclin-dependent kinases (CDKs), cyclins, and CDK inhibitors (CKIs) are valuable members of this system and their equilibrium guarantees the proper progression of the cell cycle. As expected, any dysregulation in the expression or function of these components can provide a platform for excessive cell proliferation leading to tumorigenesis. The high frequency of CDK abnormalities in human cancers, together with their druggable structure has raised the possibility that perhaps designing a series of inhibitors targeting CDKs might be advantageous for restricting the survival of tumor cells; however, their application has faced a serious concern, since these groups of serine-threonine kinases possess non-canonical functions as well. In the present review, we aimed to take a look at the biology of CDKs and then magnify their contribution to tumorigenesis. Then, by arguing the bright and dark aspects of CDK inhibition in the treatment of human cancers, we intend to reach a consensus on the application of these inhibitors in clinical settings.
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Affiliation(s)
- Mitra Zabihi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ramin Lotfi
- Clinical Research Development Center, Tohid Hospital, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Amir-Mohammad Yousefi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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10
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Off the Clock: the Non-canonical Roles of Cyclin-Dependent Kinases in Neural and Glioma Stem Cell Self-Renewal. Mol Neurobiol 2022; 59:6805-6816. [PMID: 36042143 DOI: 10.1007/s12035-022-03009-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/18/2022] [Indexed: 10/14/2022]
Abstract
Glioma stem cells (GSCs) are thought to drive growth and therapy resistance in glioblastoma (GBM) by "hijacking" at least a subset of signaling pathways active in normal neural stem cells (NSCs). Though the origins of GSCs still remain elusive, uncovering the mechanisms of self-renewing division and cell differentiation in normal NSCs has shed light on their dysfunction in GSCs. However, the distinction between self-renewing division pathways utilized by NSC and GSC becomes critical when considering options for therapeutically targeting signaling pathways that are specifically active or altered in GSCs. It is well-established that cyclin-dependent kinases (CDKs) regulate the cell cycle, yet more recent studies have shown that CDKs also play important roles in the regulation of neuronal survival, metabolism, differentiation, and self-renewal. The intimate relationship between cell cycle regulation and the cellular programs that determine self-renewing division versus cell differentiation is only beginning to be understood, yet seems to suggest potential differential vulnerabilities in GSCs. In this timely review, we focus on the role of CDKs in regulating the self-renewal properties of normal NSCs and GSCs, highlighting novel opportunities to therapeutically target self-renewing signaling pathways specifically in GBM.
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11
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Ghazale H, Park E, Vasan L, Mester J, Saleh F, Trevisiol A, Zinyk D, Chinchalongporn V, Liu M, Fleming T, Prokopchuk O, Klenin N, Kurrasch D, Faiz M, Stefanovic B, McLaurin J, Schuurmans C. Ascl1 phospho-site mutations enhance neuronal conversion of adult cortical astrocytes in vivo. Front Neurosci 2022; 16:917071. [PMID: 36061596 PMCID: PMC9434350 DOI: 10.3389/fnins.2022.917071] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Direct neuronal reprogramming, the process whereby a terminally differentiated cell is converted into an induced neuron without traversing a pluripotent state, has tremendous therapeutic potential for a host of neurodegenerative diseases. While there is strong evidence for astrocyte-to-neuron conversion in vitro, in vivo studies in the adult brain are less supportive or controversial. Here, we set out to enhance the efficacy of neuronal conversion of adult astrocytes in vivo by optimizing the neurogenic capacity of a driver transcription factor encoded by the proneural gene Ascl1. Specifically, we mutated six serine phospho-acceptor sites in Ascl1 to alanines (Ascl1SA6) to prevent phosphorylation by proline-directed serine/threonine kinases. Native Ascl1 or Ascl1SA6 were expressed in adult, murine cortical astrocytes under the control of a glial fibrillary acidic protein (GFAP) promoter using adeno-associated viruses (AAVs). When targeted to the cerebral cortex in vivo, mCherry+ cells transduced with AAV8-GFAP-Ascl1SA6-mCherry or AAV8-GFAP-Ascl1-mCherry expressed neuronal markers within 14 days post-transduction, with Ascl1SA6 promoting the formation of more mature dendritic arbors compared to Ascl1. However, mCherry expression disappeared by 2-months post-transduction of the AAV8-GFAP-mCherry control-vector. To circumvent reporter issues, AAV-GFAP-iCre (control) and AAV-GFAP-Ascl1 (or Ascl1SA6)-iCre constructs were generated and injected into the cerebral cortex of Rosa reporter mice. In all comparisons of AAV capsids (AAV5 and AAV8), GFAP promoters (long and short), and reporter mice (Rosa-zsGreen and Rosa-tdtomato), Ascl1SA6 transduced cells more frequently expressed early- (Dcx) and late- (NeuN) neuronal markers. Furthermore, Ascl1SA6 repressed the expression of astrocytic markers Sox9 and GFAP more efficiently than Ascl1. Finally, we co-transduced an AAV expressing ChR2-(H134R)-YFP, an optogenetic actuator. After channelrhodopsin photostimulation, we found that Ascl1SA6 co-transduced astrocytes exhibited a significantly faster decay of evoked potentials to baseline, a neuronal feature, when compared to iCre control cells. Taken together, our findings support an enhanced neuronal conversion efficiency of Ascl1SA6 vs. Ascl1, and position Ascl1SA6 as a critical transcription factor for future studies aimed at converting adult brain astrocytes to mature neurons to treat disease.
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Affiliation(s)
- Hussein Ghazale
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - EunJee Park
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Lakshmy Vasan
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - James Mester
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Fermisk Saleh
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Andrea Trevisiol
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Dawn Zinyk
- Sunnybrook Research Institute, Toronto, ON, Canada
| | - Vorapin Chinchalongporn
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Mingzhe Liu
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Taylor Fleming
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | | | - Natalia Klenin
- Department of Medical Genetics, Cumming School of Medicine, Hotchkiss Brain Institute, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Deborah Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, Hotchkiss Brain Institute, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Maryam Faiz
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Bojana Stefanovic
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - JoAnne McLaurin
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- *Correspondence: Carol Schuurmans,
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12
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Schaberg E, Götz M, Faissner A. The extracellular matrix molecule tenascin-C modulates cell cycle progression and motility of adult neural stem/progenitor cells from the subependymal zone. Cell Mol Life Sci 2022; 79:244. [PMID: 35430697 PMCID: PMC9013340 DOI: 10.1007/s00018-022-04259-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 02/16/2022] [Accepted: 03/18/2022] [Indexed: 11/30/2022]
Abstract
Adult neurogenesis has been described in two canonical regions of the adult central nervous system (CNS) of rodents, the subgranular zone (SGZ) of the hippocampus and the subependymal zone (SEZ) of the lateral ventricles. The stem cell niche of the SEZ provides a privileged environment composed of a specialized extracellular matrix (ECM) that comprises the glycoproteins tenascin-C (Tnc) and laminin-1 (LN1). In the present study, we investigated the function of these ECM glycoproteins in the adult stem cell niche. Adult neural stem/progenitor cells (aNSPCs) of the SEZ were prepared from wild type (Tnc+/+) and Tnc knockout (Tnc−/−) mice and analyzed using molecular and cell biological approaches. A delayed maturation of aNSPCs in Tnc−/− tissue was reflected by a reduced capacity to form neurospheres in response to epidermal growth factor (EGF). To examine a potential influence of the ECM on cell proliferation, aNSPCs of both genotypes were studied by cell tracking using digital video microscopy. aNSPCs were cultivated on three different substrates, namely, poly-d-lysine (PDL) and PDL replenished with either LN1 or Tnc for up to 6 days in vitro. On each of the three substrates aNSPCs displayed lineage trees that could be investigated with regard to cell cycle length. The latter appeared reduced in Tnc−/− aNSPCs on PDL and LN1 substrates, less so on Tnc that seemed to compensate the absence of the ECM compound to some extent. Close inspection of the lineage trees revealed a subpopulation of late dividing aNSPCslate that engaged into cycling after a notable delay. aNSPCslate exhibited a clearly different morphology, with a larger cell body and conspicuous processes. aNSPCslate reiterated the reduction in cell cycle length on all substrates tested, which was not rescued on Tnc substrates. When the migratory activity of aNSPC-derived progeny was determined, Tnc−/− neuroblasts displayed significantly longer migration tracks. This was traced to an increased rate of migration episodes compared to the wild-type cells that rested for longer time periods. We conclude that Tnc intervenes in the proliferation of aNSPCs and modulates the motility of neuroblasts in the niche of the SEZ.
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Affiliation(s)
- Elena Schaberg
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, LMU, Planegg-Martinsried, Germany
- Institute of Stem Cell Research, Helmholtz Center Munich, Biomedical Center, LMU, Planegg-Martinsried, Germany
- Synergy, Excellence Cluster for Systems Neurology, BMC, LMU, Planegg-Martinsried, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
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13
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Soares DS, Homem CC, Castro DS. Function of Proneural Genes Ascl1 and Asense in Neurogenesis: How Similar Are They? Front Cell Dev Biol 2022; 10:838431. [PMID: 35252201 PMCID: PMC8894194 DOI: 10.3389/fcell.2022.838431] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/24/2022] [Indexed: 12/31/2022] Open
Abstract
Proneural genes were initially identified in Drosophila, where pioneer work on these important regulators of neural development was performed, and from which the term proneural function was coined. Subsequently, their counterparts in vertebrates were identified, and their function in neural development extensively characterized. The function of proneural transcription factors in flies and vertebrates is, however, very distinct. In flies, proneural genes play an early role in neural induction, by endowing neural competence to ectodermal cells. In contrast, vertebrate proneural genes are expressed only after neural specification, in neural stem and progenitor cells, where they play key regulatory functions in quiescence, proliferation, and neuronal differentiation. An exception to this scenario is the Drosophila proneural gene asense, which has a late onset of expression in neural stem cells of the developing embryo and larvae, similar to its vertebrate counterparts. Although the role of Asense remains poorly investigated, its expression pattern is suggestive of functions more in line with those of vertebrate proneural genes. Here, we revise our current understanding of the multiple activities of Asense and of its closest vertebrate homologue Ascl1 in neural stem/progenitor cell biology, and discuss possible parallels between the two transcription factors in neurogenesis regulation.
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Affiliation(s)
- Diogo S. Soares
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Catarina C.F. Homem
- CEDOC, Nova Medical School, Faculdade de Ciências Médicas da Universidade Nova de Lisboa, Lisboa, Portugal
- *Correspondence: Catarina C.F. Homem, ; Diogo S. Castro,
| | - Diogo S. Castro
- i3S Instituto de Investigação e Inovação em Saúde, IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- *Correspondence: Catarina C.F. Homem, ; Diogo S. Castro,
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14
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Alaiz Noya M, Berti F, Dietrich S. Comprehensive expression analysis for the core cell cycle regulators in the chicken embryo reveals novel tissue-specific synexpression groups and similarities and differences with expression in mouse, frog and zebrafish. J Anat 2022; 241:42-66. [PMID: 35146756 PMCID: PMC9178385 DOI: 10.1111/joa.13629] [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] [Received: 09/12/2021] [Revised: 12/07/2021] [Accepted: 01/05/2022] [Indexed: 11/29/2022] Open
Abstract
The core cell cycle machinery is conserved from yeast to humans, and hence it is assumed that all vertebrates share the same set of players. Yet during vertebrate evolution, the genome was duplicated twice, followed by a further genome duplication in teleost fish. Thereafter, distinct genes were retained in different vertebrate lineages; some individual gene duplications also occurred. To which extent these diversifying tendencies were compensated by retaining the same expression patterns across homologous genes is not known. This study for the first time undertook a comprehensive expression analysis for the core cell cycle regulators in the chicken, focusing in on early neurula and pharyngula stages of development, with the latter representing the vertebrate phylotypic stage. We also compared our data with published data for the mouse, Xenopus and zebrafish, the other established vertebrate models. Our work shows that, while many genes are expressed widely, some are upregulated or specifically expressed in defined tissues of the chicken embryo, forming novel synexpression groups with markers for distinct developmental pathways. Moreover, we found that in the neural tube and in the somite, mRNAs of some of the genes investigated accumulate in a specific subcellular localisation, pointing at a novel link between the site of mRNA translation, cell cycle control and interkinetic nuclear movements. Finally, we show that expression patterns of orthologous genes may differ in the four vertebrate models. Thus, for any study investigating cell proliferation, cell differentiation, tissue regeneration, stem cell behaviour and cancer/cancer therapy, it has to be carefully examined which of the observed effects are due to the specific model organism used, and which can be generalised.
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Affiliation(s)
- Marta Alaiz Noya
- Institute for Biomedical and Biomolecular Science (IBBS), School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK.,Instituto de Neurociencias de Alicante, Universidad Miguel Hernández - Consejo Superior de Investigaciones Científicas, Alicante, Spain
| | - Federica Berti
- Institute for Biomedical and Biomolecular Science (IBBS), School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK.,Life Sciences Solutions, Thermo Fisher Scientific, Monza, Italy
| | - Susanne Dietrich
- Institute for Biomedical and Biomolecular Science (IBBS), School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
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15
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Sato Y, Umesono Y, Kuroki Y, Agata K, Hashimoto C. Proliferation maintains the undifferentiated status of stem cells: The role of the planarian cell cycle regulator Cdh1. Dev Biol 2021; 482:55-66. [PMID: 34922934 DOI: 10.1016/j.ydbio.2021.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/29/2021] [Accepted: 12/12/2021] [Indexed: 11/03/2022]
Abstract
The coincidence of cell cycle exit and differentiation has been described in a wide variety of stem cells and organisms for decades, but the causal relationship is still unclear due to the complicated regulation of the cell cycle. Here, we used the planarian Dugesia japonica since they may possess a simple cell cycle regulation in which Cdh1 is one of the factors responsible for exiting the cell cycle. When cdh1 was functionally inhibited, the planarians could not maintain their tissue homeostasis and could not regenerate their missing body parts. While the knockdown of cdh1 caused pronounced accumulation of the stem cells, the progenitor and differentiated cells were decreased. Further analyses indicated that the stem cells with cdh1 knockdown did not undergo differentiation even though they received ERK signaling activation as an induction signal. These results suggested that stem cells could not acquire differentiation competence without cell cycle exit. Thus, we propose that cell cycle regulation determines the differentiation competence and that cell cycle exit to G0 enables stem cells to undergo differentiation.
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Affiliation(s)
| | | | - Yoshihito Kuroki
- Laboratory of Regeneration Biology, National Institute for Basic Biology, Japan; Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Japan
| | - Kiyokazu Agata
- Laboratory of Regeneration Biology, National Institute for Basic Biology, Japan
| | - Chikara Hashimoto
- JT Biohistory Research Hall, Japan; Department of Biology, Graduate School of Science, Osaka University, Japan.
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16
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Direct neuronal reprogramming: Fast forward from new concepts toward therapeutic approaches. Neuron 2021; 110:366-393. [PMID: 34921778 DOI: 10.1016/j.neuron.2021.11.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/25/2021] [Accepted: 11/19/2021] [Indexed: 12/21/2022]
Abstract
Differentiated cells have long been considered fixed in their identity. However, about 20 years ago, the first direct conversion of glial cells into neurons in vitro opened the field of "direct neuronal reprogramming." Since then, neuronal reprogramming has achieved the generation of fully functional, mature neurons with remarkable efficiency, even in diseased brain environments. Beyond their clinical implications, these discoveries provided basic insights into crucial mechanisms underlying conversion of specific cell types into neurons and maintenance of neuronal identity. Here we discuss such principles, including the importance of the starter cell for shaping the outcome of neuronal reprogramming. We further highlight technical concerns for in vivo reprogramming and propose a code of conduct to avoid artifacts and pitfalls. We end by pointing out next challenges for development of less invasive cell replacement therapies for humans.
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17
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Abstract
A fundamental challenge when studying biological systems is the description of cell state dynamics. During transitions between cell states, a multitude of parameters may change - from the promoters that are active, to the RNAs and proteins that are expressed and modified. Cells can also adopt different shapes, alter their motility and change their reliance on cell-cell junctions or adhesion. These parameters are integral to how a cell behaves and collectively define the state a cell is in. Yet, technical challenges prevent us from measuring all of these parameters simultaneously and dynamically. How, then, can we comprehend cell state transitions using finite descriptions? The recent virtual workshop organised by The Company of Biologists entitled 'Cell State Transitions: Approaches, Experimental Systems and Models' attempted to address this question. Here, we summarise some of the main points that emerged during the workshop's themed discussions. We also present examples of cell state transitions and describe models and systems that are pushing forward our understanding of how cells rewire their state.
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Affiliation(s)
- Carla Mulas
- Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
| | - Agathe Chaigne
- MRC, LMCB, University College London, Gower Street, London WC1E 6BT, UK
| | - Austin Smith
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Kevin J Chalut
- Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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18
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Mechanisms of Binding Specificity among bHLH Transcription Factors. Int J Mol Sci 2021; 22:ijms22179150. [PMID: 34502060 PMCID: PMC8431614 DOI: 10.3390/ijms22179150] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 12/25/2022] Open
Abstract
The transcriptome of every cell is orchestrated by the complex network of interaction between transcription factors (TFs) and their binding sites on DNA. Disruption of this network can result in many forms of organism malfunction but also can be the substrate of positive natural selection. However, understanding the specific determinants of each of these individual TF-DNA interactions is a challenging task as it requires integrating the multiple possible mechanisms by which a given TF ends up interacting with a specific genomic region. These mechanisms include DNA motif preferences, which can be determined by nucleotide sequence but also by DNA’s shape; post-translational modifications of the TF, such as phosphorylation; and dimerization partners and co-factors, which can mediate multiple forms of direct or indirect cooperative binding. Binding can also be affected by epigenetic modifications of putative target regions, including DNA methylation and nucleosome occupancy. In this review, we describe how all these mechanisms have a role and crosstalk in one specific family of TFs, the basic helix-loop-helix (bHLH), with a very conserved DNA binding domain and a similar DNA preferred motif, the E-box. Here, we compile and discuss a rich catalog of strategies used by bHLH to acquire TF-specific genome-wide landscapes of binding sites.
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19
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Sun X, Li L, Wu B, Ge J, Zheng Y, Yu T, Zhou L, Zhang T, Yang A, Liu Z. Cell type diversity in scallop adductor muscles revealed by single-cell RNA-Seq. Genomics 2021; 113:3582-3598. [PMID: 34425225 DOI: 10.1016/j.ygeno.2021.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 07/26/2021] [Accepted: 08/18/2021] [Indexed: 11/28/2022]
Abstract
Studies on cell atlas in marine invertebrates provide a better understanding of cell types, stem cell maintenance, and lineages of cell differentiation. To investigate the molecular features of various cell types in molluscan muscles, we performed single-cell RNA sequencing (scRNA-seq) to map cell types in scallop adductor muscles. We uncovered the cell type-specific features of 20 cell clusters defined by the expression of multiple specific molecular markers. These cell clusters are mainly classified into four broad classes, including mesenchymal stem cells, muscle cells, neurons, and haemolymph cells. In particular, we identified a diverse repertoire of neurons in the striated adductor muscle, but not in the smooth muscle. We further reconstructed the cell differentiation events using all the cell clusters by single-cell pseudotemporal trajectories. By integrating dual BrdU-PCNA immunodetection, neuron-specific staining and electron microscopy observation, we showed the spatial distribution of mesenchymal stem cells and neurons in striated adductor muscle of scallops. The present findings will not only be useful to address the cell type-specific gene expression profiles in scallop muscles, but also provide valuable resources for cross-species comparison of marine organisms.
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Affiliation(s)
- Xiujun Sun
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China
| | - Li Li
- Marine Biology Institute of Shandong Province, Qingdao 266104, China
| | - Biao Wu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China
| | - Jianlong Ge
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China
| | - Yanxin Zheng
- Changdao Enhancement and Experiment Station, Chinese Academy of Fishery Sciences, Yantai 265800, China
| | - Tao Yu
- Changdao Enhancement and Experiment Station, Chinese Academy of Fishery Sciences, Yantai 265800, China
| | - Liqing Zhou
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China
| | - Tianshi Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China
| | - Aiguo Yang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China
| | - Zhihong Liu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China.
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20
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Etman AM, Abdel Mageed SS, Ali MA, El Hassab MAEM. Cyclin-Dependent Kinase as a Novel Therapeutic Target: An Endless Story. CURRENT CHEMICAL BIOLOGY 2021; 15:139-162. [DOI: 10.2174/2212796814999201123194016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/03/2020] [Accepted: 09/16/2020] [Indexed: 09/02/2023]
Abstract
Cyclin-Dependent Kinases (CDKs) are a family of enzymes that, along with their Cyclin
partners, play a crucial role in cell cycle regulation at many biological functions such as proliferation,
differentiation, DNA repair, and apoptosis. Thus, they are tightly regulated by a number of inhibitory
and activating enzymes. Deregulation of these kinases’ activity either by amplification,
overexpression or mutation of CDKs or Cyclins leads to uncontrolled proliferation of cancer cells.
Hyperactivity of these kinases has been reported in a wide variety of human cancers. Hence, CDKs
have been established as one of the most attractive pharmacological targets in the development of
promising anticancer drugs. The elucidated structural features and the well-characterized molecular
mechanisms of CDKs have been the guide in designing inhibitors to these kinases. Yet, they remain
a challenging therapeutic class as they share conserved structure similarity in their active site.
Several inhibitors have been discovered from natural sources or identified through high throughput
screening and rational drug design approaches. Most of these inhibitors target the ATP binding
pocket, therefore, they suffer from a number of limitations. Here, a growing number of ATP noncompetitive
peptides and small molecules has been reported.
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Affiliation(s)
- Ahmed Mohamed Etman
- Department of Pharmacology, Faculty of Pharmacy, Tanta University, Tanta, 31111,Egypt
| | - Sherif Sabry Abdel Mageed
- Department of Pharmacology, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr city, Cairo, 11829,Egypt
| | - Mohamed Ahmed Ali
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr city, Cairo, 11829,Egypt
| | - Mahmoud Abd El Monem El Hassab
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr city, Cairo, 11829,Egypt
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21
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Philpott A. The Use of Xenopus for Cell Biology Applications. Cold Spring Harb Protoc 2021; 2021:pdb.top105528. [PMID: 33782096 DOI: 10.1101/pdb.top105528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Problems of cell biology and the molecular controls underpinning them have been studied in the remarkably versatile Xenopus systems for many years. This versatility is showcased in several accompanying protocols, which are introduced here. One protocol demonstrates how the Xenopus embryonic ectoderm can be used to study the effects of mechanical cell deformation; another illustrates how the developing eye can be used as a platform for determining cell-cycle length. Two protocols show how extracts from Xenopus embryos can be exploited to characterize the behavior of specific intracellular proteins-specifically, to determine protein phosphorylation status and the ability to bind to chromatin. Finally, because specific antibodies to Xenopus proteins are pivotal reagents for cell biology and biochemistry applications, four protocols describing how to generate, purify, and assay the specificity of antibodies raised against Xenopus proteins are included in hopes of stimulating the expansion of these critical resources across the Xenopus community.
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Affiliation(s)
- Anna Philpott
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, United Kingdom; .,Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge, CB2 0AW, United Kingdom
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22
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Muhr J, Hagey DW. The cell cycle and differentiation as integrated processes: Cyclins and CDKs reciprocally regulate Sox and Notch to balance stem cell maintenance. Bioessays 2021; 43:e2000285. [PMID: 34008221 DOI: 10.1002/bies.202000285] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 04/15/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022]
Abstract
Development and maintenance of diverse organ systems require context-specific regulation of stem cell behaviour. We hypothesize that this is achieved via reciprocal regulation between the cell cycle machinery and differentiation factors. This idea is supported by the parallel evolutionary emergence of differentiation pathways, cell cycle components and complex multicellularity. In addition, the activities of different cell cycle phases have been found to bias cells towards stem cell maintenance or differentiation. Finally, several direct mechanistic links between these two processes have been established. Here, we focus on interactions between cyclin-CDK complexes and differentiation regulators of the Notch pathway and Sox family of transcription factors within the context of pluripotent and neural stem cells. Thus, this hypothesis formalizes the links between these two processes as an integrated network. Since such factors are common to all stem cells, better understanding their interconnections will help to explain their behaviour in health and disease.
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Affiliation(s)
- Jonas Muhr
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Daniel W Hagey
- Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
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23
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Wu F, Bard JE, Kann J, Yergeau D, Sapkota D, Ge Y, Hu Z, Wang J, Liu T, Mu X. Single cell transcriptomics reveals lineage trajectory of retinal ganglion cells in wild-type and Atoh7-null retinas. Nat Commun 2021; 12:1465. [PMID: 33674582 PMCID: PMC7935890 DOI: 10.1038/s41467-021-21704-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 02/09/2021] [Indexed: 01/31/2023] Open
Abstract
Atoh7 has been believed to be essential for establishing the retinal ganglion cell (RGC) lineage, and Pou4f2 and Isl1 are known to regulate RGC specification and differentiation. Here we report our further study of the roles of these transcription factors. Using bulk RNA-seq, we identify genes regulated by the three transcription factors, which expand our understanding of the scope of downstream events. Using scRNA-seq on wild-type and mutant retinal cells, we reveal a transitional cell state of retinal progenitor cells (RPCs) co-marked by Atoh7 and other genes for different lineages and shared by all early retinal lineages. We further discover the unexpected emergence of the RGC lineage in the absence of Atoh7. We conclude that competence of RPCs for different retinal fates is defined by lineage-specific genes co-expressed in the transitional state and that Atoh7 defines the RGC competence and collaborates with other factors to shepherd transitional RPCs to the RGC lineage.
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Affiliation(s)
- Fuguo Wu
- Department of Ophthalmology/Ross Eye Institute, University at Buffalo, Buffalo, NY, USA
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jonathan E Bard
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Julien Kann
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Donald Yergeau
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Darshan Sapkota
- Department of Ophthalmology/Ross Eye Institute, University at Buffalo, Buffalo, NY, USA
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Yichen Ge
- Department of Ophthalmology/Ross Eye Institute, University at Buffalo, Buffalo, NY, USA
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Zihua Hu
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jie Wang
- Department of Biostatistics & Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Tao Liu
- Department of Biostatistics & Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Xiuqian Mu
- Department of Ophthalmology/Ross Eye Institute, University at Buffalo, Buffalo, NY, USA.
- New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, USA.
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24
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Oproescu AM, Han S, Schuurmans C. New Insights Into the Intricacies of Proneural Gene Regulation in the Embryonic and Adult Cerebral Cortex. Front Mol Neurosci 2021; 14:642016. [PMID: 33658912 PMCID: PMC7917194 DOI: 10.3389/fnmol.2021.642016] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/26/2021] [Indexed: 12/21/2022] Open
Abstract
Historically, the mammalian brain was thought to lack stem cells as no new neurons were found to be made in adulthood. That dogma changed ∼25 years ago with the identification of neural stem cells (NSCs) in the adult rodent forebrain. However, unlike rapidly self-renewing mature tissues (e.g., blood, intestinal crypts, skin), the majority of adult NSCs are quiescent, and those that become 'activated' are restricted to a few neurogenic zones that repopulate specific brain regions. Conversely, embryonic NSCs are actively proliferating and neurogenic. Investigations into the molecular control of the quiescence-to-proliferation-to-differentiation continuum in the embryonic and adult brain have identified proneural genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs) as critical regulators. These bHLH TFs initiate genetic programs that remove NSCs from quiescence and drive daughter neural progenitor cells (NPCs) to differentiate into specific neural cell subtypes, thereby contributing to the enormous cellular diversity of the adult brain. However, new insights have revealed that proneural gene activities are context-dependent and tightly regulated. Here we review how proneural bHLH TFs are regulated, with a focus on the murine cerebral cortex, drawing parallels where appropriate to other organisms and neural tissues. We discuss upstream regulatory events, post-translational modifications (phosphorylation, ubiquitinylation), protein-protein interactions, epigenetic and metabolic mechanisms that govern bHLH TF expression, stability, localization, and consequent transactivation of downstream target genes. These tight regulatory controls help to explain paradoxical findings of changes to bHLH activity in different cellular contexts.
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Affiliation(s)
- Ana-Maria Oproescu
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Sisu Han
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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25
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Ali FR, Marcos D, Chernukhin I, Woods LM, Parkinson LM, Wylie LA, Papkovskaia TD, Davies JD, Carroll JS, Philpott A. Dephosphorylation of the Proneural Transcription Factor ASCL1 Re-Engages a Latent Post-Mitotic Differentiation Program in Neuroblastoma. Mol Cancer Res 2020; 18:1759-1766. [PMID: 33046535 PMCID: PMC7614603 DOI: 10.1158/1541-7786.mcr-20-0693] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/11/2020] [Accepted: 10/07/2020] [Indexed: 11/16/2022]
Abstract
Pediatric cancers often resemble trapped developmental intermediate states that fail to engage the normal differentiation program, typified by high-risk neuroblastoma arising from the developing sympathetic nervous system. Neuroblastoma cells resemble arrested neuroblasts trapped by a stable but aberrant epigenetic program controlled by sustained expression of a core transcriptional circuit of developmental regulators in conjunction with elevated MYCN or MYC (MYC). The transcription factor ASCL1 is a key master regulator in neuroblastoma and has oncogenic and tumor-suppressive activities in several other tumor types. Using functional mutational approaches, we find that preventing CDK-dependent phosphorylation of ASCL1 in neuroblastoma cells drives coordinated suppression of the MYC-driven core circuit supporting neuroblast identity and proliferation, while simultaneously activating an enduring gene program driving mitotic exit and neuronal differentiation. IMPLICATIONS: These findings indicate that targeting phosphorylation of ASCL1 may offer a new approach to development of differentiation therapies in neuroblastoma. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/18/12/1759/F1.large.jpg.
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Affiliation(s)
- Fahad R Ali
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Center, Cambridge Biomedical Campus, Cambridge, United Kingdom
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Daniel Marcos
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Center, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Igor Chernukhin
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
| | - Laura M Woods
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Center, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Lydia M Parkinson
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Center, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Luke A Wylie
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
| | | | - John D Davies
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Center, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Jason S Carroll
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
| | - Anna Philpott
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom.
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Center, Cambridge Biomedical Campus, Cambridge, United Kingdom
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26
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Jirawatnotai S, Dalton S, Wattanapanitch M. Role of cyclins and cyclin-dependent kinases in pluripotent stem cells and their potential as a therapeutic target. Semin Cell Dev Biol 2020; 107:63-71. [PMID: 32417217 PMCID: PMC7554155 DOI: 10.1016/j.semcdb.2020.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/30/2020] [Accepted: 05/02/2020] [Indexed: 02/09/2023]
Abstract
Over the last 15 years connections between cell cycle control, maintenance of pluripotency, and control of cell fate decisions have been firmly established. With the emergence of powerful tools, such as highly-specific small molecule inhibitors for cyclin-dependent protein kinase (CDK) activity and single-cell imaging technologies, the mechanistic links between cyclins, CDKs and regulation in PSCs in mechanistic detail has been made possible. In this review, we discuss new developments that mechanistically link the CDK regulatory network to control of cell fate decisions, including maintenance of the pluripotent state. Overall, these findings have potential to impact the translational applications of stem cells in regenerative medicine, drug discovery and cancer treatment.
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Affiliation(s)
- Siwanon Jirawatnotai
- Siriraj Center of Research for Excellence for Systems Pharmacology, Department of Pharmacology, Faculty of Medicine, Siriraj Medical School, Mahidol University, Bangkok, 10700, Thailand
| | - Stephen Dalton
- Center for Molecular Medicine and Department of Biochemistry and Molecular Biology, 325 Riverbend Road, The University of Georgia, Athens, GA, 30602, USA
| | - Methichit Wattanapanitch
- Siriraj Center for Regenerative Medicine, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
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Robledinos-Antón N, Escoll M, Guan KL, Cuadrado A. TAZ Represses the Neuronal Commitment of Neural Stem Cells. Cells 2020; 9:cells9102230. [PMID: 33023162 PMCID: PMC7600930 DOI: 10.3390/cells9102230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/26/2020] [Accepted: 09/29/2020] [Indexed: 12/14/2022] Open
Abstract
The mechanisms involved in regulation of quiescence, proliferation, and reprogramming of Neural Stem Progenitor Cells (NSPCs) of the mammalian brain are still poorly defined. Here, we studied the role of the transcriptional co-factor TAZ, regulated by the WNT and Hippo pathways, in the homeostasis of NSPCs. We found that, in the murine neurogenic niches of the striatal subventricular zone and the dentate gyrus granular zone, TAZ is highly expressed in NSPCs and declines with ageing. Moreover, TAZ expression is lost in immature neurons of both neurogenic regions. To characterize mechanistically the role of TAZ in neuronal differentiation, we used the midbrain-derived NSPC line ReNcell VM to replicate in a non-animal model the factors influencing NSPC differentiation to the neuronal lineage. TAZ knock-down and forced expression in NSPCs led to increased and reduced neuronal differentiation, respectively. TEADs-knockdown indicated that these TAZ co-partners are required for the suppression of NSPCs commitment to neuronal differentiation. Genetic manipulation of the TAZ/TEAD system showed its participation in transcriptional repression of SOX2 and the proneuronal genes ASCL1, NEUROG2, and NEUROD1, leading to impediment of neurogenesis. TAZ is usually considered a transcriptional co-activator promoting stem cell proliferation, but our study indicates an additional function as a repressor of neuronal differentiation.
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Affiliation(s)
- Natalia Robledinos-Antón
- Instituto de Investigaciones Biomédicas “Alberto Sols” UAM-CSIC, 28029 Madrid, Spain; (N.R.-A.); (M.E.)
- Instituto de Investigación Sanitaria La Paz (IdiPaz), 28029 Madrid, Spain
- Department of Biochemistry, Faculty of Medicine, Autonomous University of Madrid, 28029 Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) ISCIII, 28031 Madrid, Spain
| | - Maribel Escoll
- Instituto de Investigaciones Biomédicas “Alberto Sols” UAM-CSIC, 28029 Madrid, Spain; (N.R.-A.); (M.E.)
- Instituto de Investigación Sanitaria La Paz (IdiPaz), 28029 Madrid, Spain
- Department of Biochemistry, Faculty of Medicine, Autonomous University of Madrid, 28029 Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) ISCIII, 28031 Madrid, Spain
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA;
| | - Antonio Cuadrado
- Instituto de Investigaciones Biomédicas “Alberto Sols” UAM-CSIC, 28029 Madrid, Spain; (N.R.-A.); (M.E.)
- Instituto de Investigación Sanitaria La Paz (IdiPaz), 28029 Madrid, Spain
- Department of Biochemistry, Faculty of Medicine, Autonomous University of Madrid, 28029 Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) ISCIII, 28031 Madrid, Spain
- Correspondence: ; Tel.: +34-915-854-383; Fax: +34-915-854-401
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28
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Urun FR, Moore AW. Visualizing Cell Cycle Phase Organization and Control During Neural Lineage Elaboration. Cells 2020; 9:E2112. [PMID: 32957483 PMCID: PMC7565168 DOI: 10.3390/cells9092112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 11/16/2022] Open
Abstract
In neural precursors, cell cycle regulators simultaneously control both progression through the cell cycle and the probability of a cell fate switch. Precursors act in lineages, where they transition through a series of cell types, each of which has a unique molecular identity and cellular behavior. Thus, investigating links between cell cycle and cell fate control requires simultaneous identification of precursor type and cell cycle phase, as well as an ability to read out additional regulatory factor expression or activity. We use a combined FUCCI-EdU labelling protocol to do this, and then applied it to the embryonic olfactory neural lineage, in which the spatial position of a cell correlates with its precursor identity. Using this integrated model, we find the CDKi p27KIP1 has different regulation relative to cell cycle phase in neural stem cells versus intermediate precursors. In addition, Hes1, which is the principle transcriptional driver of neural stem cell self-renewal, surprisingly does not regulate p27KIP1 in this cell type. Rather, Hes1 indirectly represses p27KIP1 levels in the intermediate precursor cells downstream in the lineage. Overall, the experimental model described here enables investigation of cell cycle and cell fate control linkage from a single precursor through to a lineage systems level.
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Affiliation(s)
- Fatma Rabia Urun
- Laboratory for Neurodiversity, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan;
- Graduate School of Science and Engineering, Saitama University, Sakura-ku, Saitama 338-8570, Japan
| | - Adrian W Moore
- Laboratory for Neurodiversity, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan;
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29
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Kuzmicz-Kowalska K, Kicheva A. Regulation of size and scale in vertebrate spinal cord development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e383. [PMID: 32391980 PMCID: PMC8244110 DOI: 10.1002/wdev.383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/25/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022]
Abstract
All vertebrates have a spinal cord with dimensions and shape specific to their species. Yet how species‐specific organ size and shape are achieved is a fundamental unresolved question in biology. The formation and sculpting of organs begins during embryonic development. As it develops, the spinal cord extends in anterior–posterior direction in synchrony with the overall growth of the body. The dorsoventral (DV) and apicobasal lengths of the spinal cord neuroepithelium also change, while at the same time a characteristic pattern of neural progenitor subtypes along the DV axis is established and elaborated. At the basis of these changes in tissue size and shape are biophysical determinants, such as the change in cell number, cell size and shape, and anisotropic tissue growth. These processes are controlled by global tissue‐scale regulators, such as morphogen signaling gradients as well as mechanical forces. Current challenges in the field are to uncover how these tissue‐scale regulatory mechanisms are translated to the cellular and molecular level, and how regulation of distinct cellular processes gives rise to an overall defined size. Addressing these questions will help not only to achieve a better understanding of how size is controlled, but also of how tissue size is coordinated with the specification of pattern. This article is categorized under:Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Signaling Pathways > Global Signaling Mechanisms Nervous System Development > Vertebrates: General Principles
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30
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Kimata Y, Leturcq M, Aradhya R. Emerging roles of metazoan cell cycle regulators as coordinators of the cell cycle and differentiation. FEBS Lett 2020; 594:2061-2083. [PMID: 32383482 DOI: 10.1002/1873-3468.13805] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 01/10/2023]
Abstract
In multicellular organisms, cell proliferation must be tightly coordinated with other developmental processes to form functional tissues and organs. Despite significant advances in our understanding of how the cell cycle is controlled by conserved cell-cycle regulators (CCRs), how the cell cycle is coordinated with cell differentiation in metazoan organisms and how CCRs contribute to this process remain poorly understood. Here, we review the emerging roles of metazoan CCRs as intracellular proliferation-differentiation coordinators in multicellular organisms. We illustrate how major CCRs regulate cellular events that are required for cell fate acquisition and subsequent differentiation. To this end, CCRs employ diverse mechanisms, some of which are separable from those underpinning the conventional cell-cycle-regulatory functions of CCRs. By controlling cell-type-specific specification/differentiation processes alongside the progression of the cell cycle, CCRs enable spatiotemporal coupling between differentiation and cell proliferation in various developmental contexts in vivo. We discuss the significance and implications of this underappreciated role of metazoan CCRs for development, disease and evolution.
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Affiliation(s)
- Yuu Kimata
- School of Life Science and Technology, ShanghaiTech University, China
| | - Maïté Leturcq
- School of Life Science and Technology, ShanghaiTech University, China
| | - Rajaguru Aradhya
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, Kerala, India
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31
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Chen M, Ahmadian M, Watson LT, Cao Y. Finding acceptable parameter regions of stochastic Hill functions for multisite phosphorylation mechanism. J Chem Phys 2020; 152:124108. [DOI: 10.1063/1.5143004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. Chen
- Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - M. Ahmadian
- Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - L. T. Watson
- Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Y. Cao
- Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061, USA
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32
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Xue Y, Theisen TC, Rastogi S, Ferrel A, Quake SR, Boothroyd JC. A single-parasite transcriptional atlas of Toxoplasma Gondii reveals novel control of antigen expression. eLife 2020; 9:e54129. [PMID: 32065584 PMCID: PMC7180058 DOI: 10.7554/elife.54129] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/16/2020] [Indexed: 12/21/2022] Open
Abstract
Toxoplasma gondii, a protozoan parasite, undergoes a complex and poorly understood developmental process that is critical for establishing a chronic infection in its intermediate hosts. Here, we applied single-cell RNA-sequencing (scRNA-seq) on >5,400 Toxoplasma in both tachyzoite and bradyzoite stages using three widely studied strains to construct a comprehensive atlas of cell-cycle and asexual development, revealing hidden states and transcriptional factors associated with each developmental stage. Analysis of SAG1-related sequence (SRS) antigenic repertoire reveals a highly heterogeneous, sporadic expression pattern unexplained by measurement noise, cell cycle, or asexual development. Furthermore, we identified AP2IX-1 as a transcription factor that controls the switching from the ubiquitous SAG1 to rare surface antigens not previously observed in tachyzoites. In addition, comparative analysis between Toxoplasma and Plasmodium scRNA-seq results reveals concerted expression of gene sets, despite fundamental differences in cell division. Lastly, we built an interactive data-browser for visualization of our atlas resource.
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Affiliation(s)
- Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, United States
| | - Terence C Theisen
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Suchita Rastogi
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Abel Ferrel
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, United States
- Department of Applied Physics, Stanford University, Stanford, United States
- Chan Zuckerberg Biohub, San Francisco, United States
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
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33
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Huilgol D, Venkataramani P, Nandi S, Bhattacharjee S. Transcription Factors That Govern Development and Disease: An Achilles Heel in Cancer. Genes (Basel) 2019; 10:E794. [PMID: 31614829 PMCID: PMC6826716 DOI: 10.3390/genes10100794] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/05/2019] [Accepted: 10/08/2019] [Indexed: 12/22/2022] Open
Abstract
Development requires the careful orchestration of several biological events in order to create any structure and, eventually, to build an entire organism. On the other hand, the fate transformation of terminally differentiated cells is a consequence of erroneous development, and ultimately leads to cancer. In this review, we elaborate how development and cancer share several biological processes, including molecular controls. Transcription factors (TF) are at the helm of both these processes, among many others, and are evolutionarily conserved, ranging from yeast to humans. Here, we discuss four families of TFs that play a pivotal role and have been studied extensively in both embryonic development and cancer-high mobility group box (HMG), GATA, paired box (PAX) and basic helix-loop-helix (bHLH) in the context of their role in development, cancer, and their conservation across several species. Finally, we review TFs as possible therapeutic targets for cancer and reflect on the importance of natural resistance against cancer in certain organisms, yielding knowledge regarding TF function and cancer biology.
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Affiliation(s)
- Dhananjay Huilgol
- Bungtown Road, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA.
| | | | - Saikat Nandi
- Bungtown Road, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA.
| | - Sonali Bhattacharjee
- Bungtown Road, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA.
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34
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The cell cycle in stem cell proliferation, pluripotency and differentiation. Nat Cell Biol 2019; 21:1060-1067. [PMID: 31481793 DOI: 10.1038/s41556-019-0384-4] [Citation(s) in RCA: 180] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 07/24/2019] [Indexed: 12/30/2022]
Abstract
Cyclins, cyclin-dependent kinases and other components of the core cell cycle machinery drive cell division. Growing evidence indicates that this machinery operates in a distinct fashion in some mammalian stem cell types, such as pluripotent embryonic stem cells. In this Review, we discuss our current knowledge of how cell cycle proteins mechanistically link cell proliferation, pluripotency and cell fate specification. We focus on embryonic stem cells, induced pluripotent stem cells and embryonic neural stem/progenitor cells.
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35
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McDowell GS, Philpott A. Calculating the Degradation Rate of Individual Proteins Using Xenopus Extract Systems. Cold Spring Harb Protoc 2019; 2019:pdb.prot103481. [PMID: 29769400 DOI: 10.1101/pdb.prot103481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Xenopus extract system has been used extensively as a simple, quick, and robust method for assessing the stability of proteins against proteasomal degradation. In this protocol, methods are provided for assessing the half-life of in vitro translated radiolabeled proteins using Xenopus egg or embryo extracts.
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Affiliation(s)
- Gary S McDowell
- Future of Research, Abington, Massachusetts 02351;
- Manylabs, San Francisco, California 94103
| | - Anna Philpott
- Department of Oncology, MRC/Hutchison Research Centre, Cambridge CB21XZ, United Kingdom;
- Wellcome Trust-Medical Research Centre Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB21QR, United Kingdom
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36
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Niapour A, Ghasemi Hamidabadi H, Niapour N, Mohammadi P, Sharifi Pasandi M, Malekzadeh V. Pharmacological Notch pathway inhibition leads to cell cycle arrest and stimulates ascl1 and neurogenin2 genes expression in dental pulp stem cells-derived neurospheres. Biotechnol Lett 2019; 41:873-887. [PMID: 31073804 DOI: 10.1007/s10529-019-02687-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 05/05/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Human dental pulp-derived stem cells (hDPSCs) are becoming an attractive source for cell-based neurorestorative therapies. As such, it is important to understand the molecular mechanisms that regulate the differentiation of hDPSCs toward the neuronal fate. Notch signaling plays key roles in neural stem/progenitor cells (NS/PCs) maintenance and prevention of their differentiation. The aim of this study was to address the effects of Notch signaling inhibition on neurosphere formation of hDPSCs and neuronal differentiation of hDPSCs-neurospheres. RESULTS hDPSCs were isolated from third molar teeth. The cultivated hDPSCs highly expressed CD90 and CD44 and minimally presented CD34 and CD45 surface markers. The osteo/adipogenic differentiation of hDPSCs was documented. hDPSCs were cultured in neural induction medium and N-[N-(3,5-difluorophenacetyl-L-alanyl)]-Sphenylglycine t-butyl ester (DAPT) was applied to impede Notch signaling during transformation into spheres or on the formed neurospheres. Our results showed that the size and number of neurospheres decreased and the expression profile of nestin, sox1 and pax6 genes reduced provided DAPT. Treatment of the formed neurospheres with DAPT resulted in the cleaved Notch1 reduction, G0/G1 arrest and a decline in L-lactate production. DAPT significantly reduced hes1 and hey1 genes, while ascl1 and neurogenin2 expressions augmented. The number of MAP2 positive cells improved in the DAPT-treated group. CONCLUSIONS Our findings demonstrated the Notch activity in hDPSCs-neurospheres. DAPT treatment positively regulated proneural genes expression and increased neuronal-like differentiation.
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Affiliation(s)
- Ali Niapour
- Research Laboratory for Embryology and Stem Cells, Department of Anatomical Sciences, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran.
| | - Hatef Ghasemi Hamidabadi
- Department of Anatomy and Cell Biology, Immunogenetic Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Anatomy & Cell Biology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Nazila Niapour
- Research Laboratory for Embryology and Stem Cells, Department of Anatomical Sciences, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Perham Mohammadi
- Department of Pharmacology and Toxicology, School of Pharmacy, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Marzieh Sharifi Pasandi
- Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Vadoud Malekzadeh
- Research Laboratory for Embryology and Stem Cells, Department of Anatomical Sciences, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
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37
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Urbach A, Witte OW. Divide or Commit - Revisiting the Role of Cell Cycle Regulators in Adult Hippocampal Neurogenesis. Front Cell Dev Biol 2019; 7:55. [PMID: 31069222 PMCID: PMC6491688 DOI: 10.3389/fcell.2019.00055] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 03/28/2019] [Indexed: 12/21/2022] Open
Abstract
The adult dentate gyrus continuously generates new neurons that endow the brain with increased plasticity, helping to cope with changing environmental and cognitive demands. The process leading to the birth of new neurons spans several precursor stages and is the result of a coordinated series of fate decisions, which are tightly controlled by extrinsic signals. Many of these signals act through modulation of cell cycle (CC) components, not only to drive proliferation, but also for linage commitment and differentiation. In this review, we provide a comprehensive overview on key CC components and regulators, with emphasis on G1 phase, and analyze their specific functions in precursor cells of the adult hippocampus. We explore their role for balancing quiescence versus self-renewal, which is essential to maintain a lifelong pool of neural stem cells while producing new neurons “on demand.” Finally, we discuss available evidence and controversies on the impact of CC/G1 length on proliferation versus differentiation decisions.
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Affiliation(s)
- Anja Urbach
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Otto W Witte
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
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38
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MacKenzie RK, Sankar PR, Bendall AJ. Dlx5 and Dlx6 can antagonize cell division at the G 1/S checkpoint. BMC Mol Cell Biol 2019; 20:8. [PMID: 31041891 PMCID: PMC6460778 DOI: 10.1186/s12860-019-0191-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 04/02/2019] [Indexed: 11/17/2022] Open
Abstract
Background Dlx5 and Dlx6 stimulate differentiation of diverse progenitors during embryonic development. Their actions as pro-differentiation transcription factors includes the up-regulation of differentiation markers but the extent to which differentiation may also be stimulated by regulation of the cell cycle has not been addressed. Results We document that expression of Dlx5 and Dlx6 antagonizes cell proliferation in a variety of cell types without inducing apoptosis or promoting cell cycle exit. Rather, a variety of evidence indicates that elevated Dlx5 and Dlx6 expression reduces the proportion of cells in S phase and affects the length of the cell cycle. Conclusions Antagonism of S-phase entry by Dlx5 and Dlx6 proteins likely represents a lineage-independent function to effect Dlx-mediated differentiation in multiple progenitor cell types.
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Affiliation(s)
- Rachel K MacKenzie
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd East, Guelph, Ontario, N1G 2W1, Canada
| | - Parvathy Ravi Sankar
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd East, Guelph, Ontario, N1G 2W1, Canada
| | - Andrew J Bendall
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd East, Guelph, Ontario, N1G 2W1, Canada.
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39
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Hardwick LJA, Davies JD, Philpott A. Multi-site phosphorylation controls the neurogenic and myogenic activity of E47. Biochem Biophys Res Commun 2019; 511:111-116. [PMID: 30773262 PMCID: PMC6405440 DOI: 10.1016/j.bbrc.2019.02.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/08/2019] [Indexed: 11/17/2022]
Abstract
The superfamily of basic-Helix-Loop-Helix (bHLH) transcription factors influence cell fate in all three embryonic germ layers, and the tissue-specific class II factors have received prominent attention for their potent ability to direct differentiation during development and in cellular reprogramming. The activity of many class II bHLH proteins driving differentiation, and the inhibitory class VI bHLH factor Hes1, is controlled by phosphorylation on multiple sites by Cyclin-dependent kinases (Cdks). As class II proteins are generally thought to be active through hetero-dimerisation with the ubiquitously expressed class I E proteins, regulation of class I transcription factors such as E47 may influence the activity of multiple tissue-specific bHLH proteins. Using differentiation of nerve and muscle in Xenopus frog embryos as a model system, we set out to explore whether with the ubiquitously expressed class I E protein E47 that hetero-dimerises with Class II bHLHs to control their activity, is also regulated by multi-site phosphorylation. We demonstrate that E47 can be readily phosphorylated by Cdks on multiple sites in vitro, while ectopically-expressed E47 exists in multiple phosphorylated forms in Xenopus embryos. Preventing multi-site phosphorylation using a phospho-mutant version of E47 enhances the neurogenic and myogenic activity of three different class II bHLH reprogramming factors, and also when E47 acts in hetero-dimerisation with endogenous proteins. Mechanistically, unlike phospho-regulation of class II bHLH factors, we find that preventing phosphorylation of E47 increases the amount of chromatin-bound E47 protein but without affecting its overall protein stability. Thus, multi-site phosphorylation is a conserved regulatory mechanism across the bHLH superfamily that can be manipulated to enhance cellular differentiation. E47 is phosphorylated in Xenopus embryos on up to 13 conserved SP/TP sites. In vitro, E47 protein can be phosphorylated by Cyclin-dependent-kinases. Under-phosphorylated E47 enhances activity of 3 bHLH reprogramming factors. Under-phosphorylated E47 enhances neuronal differentiation by hetero-dimerisation. E47 phospho-status alters chromatin binding but not overall protein stability.
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Affiliation(s)
- Laura J A Hardwick
- Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK; Peterhouse, University of Cambridge, Trumpington Street, Cambridge, CB2 1RD, UK.
| | - John D Davies
- Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK; Wellcome Trust/MRC Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK.
| | - Anna Philpott
- Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK; Wellcome Trust/MRC Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK.
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40
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Xue Y, Zhan X, Sun S, Karuppagounder SS, Xia S, Dawson VL, Dawson TM, Laterra J, Zhang J, Ying M. Synthetic mRNAs Drive Highly Efficient iPS Cell Differentiation to Dopaminergic Neurons. Stem Cells Transl Med 2019; 8:112-123. [PMID: 30387318 PMCID: PMC6344911 DOI: 10.1002/sctm.18-0036] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 08/03/2018] [Accepted: 09/07/2018] [Indexed: 12/18/2022] Open
Abstract
Proneural transcription factors (TFs) drive highly efficient differentiation of pluripotent stem cells to lineage-specific neurons. However, current strategies mainly rely on genome-integrating viruses. Here, we used synthetic mRNAs coding two proneural TFs (Atoh1 and Ngn2) to differentiate induced pluripotent stem cells (iPSCs) into midbrain dopaminergic (mDA) neurons. mRNAs coding Atoh1 and Ngn2 with defined phosphosite modifications led to higher and more stable protein expression, and induced more efficient neuron conversion, as compared to mRNAs coding wild-type proteins. Using these two modified mRNAs with morphogens, we established a 5-day protocol that can rapidly generate mDA neurons with >90% purity from normal and Parkinson's disease iPSCs. After in vitro maturation, these mRNA-induced mDA (miDA) neurons recapitulate key biochemical and electrophysiological features of primary mDA neurons and can provide high-content neuron cultures for drug discovery. Proteomic analysis of Atoh1-binding proteins identified the nonmuscle myosin II (NM-II) complex as a new binding partner of nuclear Atoh1. The NM-II complex, commonly known as an ATP-dependent molecular motor, binds more strongly to phosphosite-modified Atoh1 than the wild type. Blebbistatin, an NM-II complex antagonist, and bradykinin, an NM-II complex agonist, inhibited and promoted, respectively, the transcriptional activity of Atoh1 and the efficiency of miDA neuron generation. These findings established the first mRNA-driven strategy for efficient iPSC differentiation to mDA neurons. We further identified the NM-II complex as a positive modulator of Atoh1-driven neuron differentiation. The methodology described here will facilitate the development of mRNA-driven differentiation strategies for generating iPSC-derived progenies widely applicable to disease modeling and cell replacement therapy. Stem Cells Translational Medicine 2019;8:112&12.
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Affiliation(s)
- Yingchao Xue
- Department of Immunology, Research Center on Pediatric Development and DiseasesInstitute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular BiologyBeijingPeople's Republic of China
- Hugo W. Moser Research Institute at Kennedy KriegerBaltimoreMarylandUSA
| | - Xiping Zhan
- Department of Physiology and BiophysicsHoward UniversityWashingtonDistrict of ColumbiaUSA
| | - Shisheng Sun
- College of Life Sciences, Northwest UniversityXi'anPeople's Republic of China
| | - Senthilkumar S. Karuppagounder
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of MedicineBaltimoreMarylandUSA
- Adrienne Helis Malvin Medical Research FoundationNew OrleansLouisianaUSA
| | - Shuli Xia
- Hugo W. Moser Research Institute at Kennedy KriegerBaltimoreMarylandUSA
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Valina L. Dawson
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of MedicineBaltimoreMarylandUSA
- Adrienne Helis Malvin Medical Research FoundationNew OrleansLouisianaUSA
- Department of NeuroscienceJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of PhysiologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Ted M. Dawson
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of MedicineBaltimoreMarylandUSA
- Adrienne Helis Malvin Medical Research FoundationNew OrleansLouisianaUSA
- Department of NeuroscienceJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of Pharmacology and Molecular SciencesJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - John Laterra
- Hugo W. Moser Research Institute at Kennedy KriegerBaltimoreMarylandUSA
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of NeuroscienceJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of OncologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Jianmin Zhang
- Department of Immunology, Research Center on Pediatric Development and DiseasesInstitute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular BiologyBeijingPeople's Republic of China
| | - Mingyao Ying
- Hugo W. Moser Research Institute at Kennedy KriegerBaltimoreMarylandUSA
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
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N-terminal phosphorylation of xHes1 controls inhibition of primary neurogenesis in Xenopus. Biochem Biophys Res Commun 2018; 509:557-563. [PMID: 30600182 PMCID: PMC6363968 DOI: 10.1016/j.bbrc.2018.12.135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 12/18/2018] [Indexed: 11/23/2022]
Abstract
The processes of cell proliferation and differentiation are intimately linked during embryogenesis, and the superfamily of (basic) Helix-Loop-Helix (bHLH) transcription factors play critical roles in these events. For example, neuronal differentiation is promoted by class II bHLH proneural proteins such as Ngn2 and Ascl1, while class VI Hes proteins act to restrain differentiation and promote progenitor maintenance. We have previously described multi-site phosphorylation as a key regulator of tissue specific class II bHLH proteins in all three embryonic germ layers, and this enables coordination of differentiation with the cell cycle. Hes1 homologues also show analogous conserved proline directed kinase sites. Here we have used formation of Xenopus primary neurons to investigate the effects of xHes1 multi-site phosphorylation on both endogenous and ectopic proneural protein-induced neurogenesis. We find that xHes1 is phosphorylated in vivo, and preventing phosphorylation on three conserved SP/TP sites in the N terminus of the protein enhances xHes1 protein stability and repressor activity. Mechanistically, compared to wild-type xHes1, phospho-mutant xHes1 exhibits greater repression of Ngn2 transcription as well as producing a greater reduction in Ngn2 protein stability and chromatin binding. We propose that cell cycle dependent phosphorylation of class VI Hes proteins may act alongside similar regulation of class II bHLH proneural proteins to co-ordinate their activity. xHes1 is phosphorylated in Xenopus embryos on conserved N terminal SP/TP sites. In vitro, xHes1 protein can be phosphorylated by Cyclin-dependent-kinases. Under-phosphorylated xHes1 has increased protein stability relative to WT xHes1. Under-phosphorylated xHes1 has enhanced inhibitory activity during neurogenesis. xHes1 reduces Ngn2 expression, protein stability and chromatin binding.
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42
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Hardwick LJ, Philpott A. Interaction between opposing modes of phospho-regulation of the proneural proteins Ascl1 and Ngn2. Wellcome Open Res 2018; 3:129. [PMID: 30430141 PMCID: PMC6206610 DOI: 10.12688/wellcomeopenres.14848.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2018] [Indexed: 12/17/2022] Open
Abstract
From the relatively simple nervous system of Drosophila to the elaborate mammalian cortex, neurogenesis requires exceptional spatial and temporal precision to co-ordinate progenitor cell proliferation and subsequent differentiation to a diverse range of neurons and glia. A limited number of transiently expressed proneural basic-helix-loop-helix (bHLH) transcription factors, for example achaete-scute-complex (as-c) and atonal (ato) in Drosophila and the vertebrate homologues Ascl1 and Neurogenin2 (Ngn2), are able to orchestrate the onset of neuronal determination, context-dependent subtype selection and even influence later aspects of neuronal migration and maturation. Within the last decade, two models have emerged to explain how the temporal activity of proneural determination factors is regulated by phosphorylation at distinct sites. One model describes how cell-cycle associated phosphorylation on multiple sites in the N and C termini of vertebrate proneural proteins limits neuronal differentiation in cycling progenitor cells. A second model describes phosphorylation on a single site in the bHLH domain of Drosophila atonal that acts as a binary switch, where phosphorylation terminates proneural activity. Here we combine activating mutations of phosphorylation sites in the N- and C- termini with an inhibitory phospho-mimetic mutation in the bHLH domain of Ascl1 and Ngn2 proteins, and test their functions in vivo using Xenopus embryos to determine which mode of phospho-regulation dominates. Enhancing activity by preventing N- and C terminal phosphorylation cannot overcome the inhibitory effect of mimicking phosphorylation of the bHLH domain. Thus we have established a hierarchy between these two modes of proneural protein control and suggest a model of temporal regulation for proneural protein activity.
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Affiliation(s)
- Laura J.A. Hardwick
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, UK
- Peterhouse, University of Cambridge, Cambridge, CB2 1RD, UK
| | - Anna Philpott
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
- Department of Oncology, University of Cambridge, Cambridge, CB2 0XZ, UK
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43
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Cell cycle-dependent phosphorylation and regulation of cellular differentiation. Biochem Soc Trans 2018; 46:1083-1091. [PMID: 30242121 DOI: 10.1042/bst20180276] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/02/2018] [Accepted: 08/03/2018] [Indexed: 02/07/2023]
Abstract
Embryogenesis requires an exquisite regulation of cell proliferation, cell cycle withdrawal and differentiation into a massively diverse range of cells at the correct time and place. Stem cells also remain to varying extents in different adult tissues, acting in tissue homeostasis and repair. Therefore, regulated proliferation and subsequent differentiation of stem and progenitor cells remains pivotal throughout life. Recent advances have characterised the cell cycle dynamics, epigenetics, transcriptome and proteome accompanying the transition from proliferation to differentiation, revealing multiple bidirectional interactions between the cell cycle machinery and factors driving differentiation. Here, we focus on a direct mechanistic link involving phosphorylation of differentiation-associated transcription factors by cell cycle-associated Cyclin-dependent kinases. We discuss examples from the three embryonic germ layers to illustrate this regulatory mechanism that co-ordinates the balance between cell proliferation and differentiation.
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44
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Tomic G, Morrissey E, Kozar S, Ben-Moshe S, Hoyle A, Azzarelli R, Kemp R, Chilamakuri CSR, Itzkovitz S, Philpott A, Winton DJ. Phospho-regulation of ATOH1 Is Required for Plasticity of Secretory Progenitors and Tissue Regeneration. Cell Stem Cell 2018; 23:436-443.e7. [PMID: 30100168 PMCID: PMC6138952 DOI: 10.1016/j.stem.2018.07.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/25/2018] [Accepted: 07/06/2018] [Indexed: 01/07/2023]
Abstract
The intestinal epithelium is largely maintained by self-renewing stem cells but with apparently committed progenitors also contributing, particularly following tissue damage. However, the mechanism of, and requirement for, progenitor plasticity in mediating pathological response remain unknown. Here we show that phosphorylation of the transcription factor Atoh1 is required for both the contribution of secretory progenitors to the stem cell pool and for a robust regenerative response. As confirmed by lineage tracing, Atoh1+ cells (Atoh1(WT)CreERT2 mice) give rise to multilineage intestinal clones both in the steady state and after tissue damage. In a phosphomutant Atoh1(9S/T-A)CreERT2 line, preventing phosphorylation of ATOH1 protein acts to promote secretory differentiation and inhibit the contribution of progenitors to self-renewal. Following chemical colitis, Atoh1+ cells of Atoh1(9S/T-A)CreERT2 mice have reduced clonogenicity that affects overall regeneration. Progenitor plasticity maintains robust self-renewal in the intestinal epithelium, and the balance between stem and progenitor fate is directly coordinated by ATOH1 multisite phosphorylation.
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Affiliation(s)
- Goran Tomic
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | - Edward Morrissey
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Sarah Kozar
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | - Shani Ben-Moshe
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Alice Hoyle
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | - Roberta Azzarelli
- Department of Oncology, Hutchison/Medical Research Council (MRC) Research Centre, University of Cambridge, Cambridge CB2 0XZ, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
| | - Richard Kemp
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | | | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Anna Philpott
- Department of Oncology, Hutchison/Medical Research Council (MRC) Research Centre, University of Cambridge, Cambridge CB2 0XZ, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK.
| | - Douglas J Winton
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK.
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45
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Aledo JC. Multisite phosphorylation provides a reliable mechanism for making decisions in noisy environments. FEBS J 2018; 285:3729-3737. [PMID: 30112800 DOI: 10.1111/febs.14636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 06/11/2018] [Accepted: 08/13/2018] [Indexed: 11/27/2022]
Abstract
The ability to make decisions at the cellular level is absolutely critical for the survival of organisms. Eukaryotic cells are constantly making binary decisions in response to internal and environmental signals. Among the most notable transducers of information are protein kinases. The regulation of these signaling proteins often relies on the activity of other protein kinases located upstream in the signaling cascade. However, these signaling systems are by their own nature an important source of molecular noise. Herein, we have assessed the role of multisite phosphorylation in detecting signals in the face of molecular noise. To address this issue, we have conceptually envisioned the biochemical transduction machinery as a classifier model that can lead to four possible outputs: true positives and negatives, and false positives and negatives. In this probabilistic framework, we show that multisite phosphorylation represents a mechanism to filter noise during the decision-making process. We present results showing that nonessential phosphorylation sites contribute to increase the rate of true positives while, at the same time, they can lessen the rate of false positives. This simultaneous increase in sensitivity and specificity, makes multisite phosphorylation a valuable and easily implemented mechanism to reliably transduce information in noisy contexts.
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Affiliation(s)
- Juan Carlos Aledo
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Spain
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46
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Le Dréau G, Escalona R, Fueyo R, Herrera A, Martínez JD, Usieto S, Menendez A, Pons S, Martinez-Balbas MA, Marti E. E proteins sharpen neurogenesis by modulating proneural bHLH transcription factors' activity in an E-box-dependent manner. eLife 2018; 7:37267. [PMID: 30095408 PMCID: PMC6126921 DOI: 10.7554/elife.37267] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 08/09/2018] [Indexed: 12/18/2022] Open
Abstract
Class II HLH proteins heterodimerize with class I HLH/E proteins to regulate transcription. Here, we show that E proteins sharpen neurogenesis by adjusting the neurogenic strength of the distinct proneural proteins. We find that inhibiting BMP signaling or its target ID2 in the chick embryo spinal cord, impairs the neuronal production from progenitors expressing ATOH1/ASCL1, but less severely that from progenitors expressing NEUROG1/2/PTF1a. We show this context-dependent response to result from the differential modulation of proneural proteins’ activity by E proteins. E proteins synergize with proneural proteins when acting on CAGSTG motifs, thereby facilitating the activity of ASCL1/ATOH1 which preferentially bind to such motifs. Conversely, E proteins restrict the neurogenic strength of NEUROG1/2 by directly inhibiting their preferential binding to CADATG motifs. Since we find this mechanism to be conserved in corticogenesis, we propose this differential co-operation of E proteins with proneural proteins as a novel though general feature of their mechanism of action. The brain and spinal cord are made up of a range of cell types that carry out different roles within the central nervous system. Each type of neuron is uniquely specialized to do its job. Neurons are produced early during development, when they differentiate from a group of cells called neural progenitor cells. Within these groups, molecules called proneural proteins control which types of neurons will develop from the neural progenitor cells, and how many of them. Proneural proteins work by binding to specific patterns in the DNA, called E-boxes, with the help of E proteins. E proteins are typically understood to be passive partners, working with each different proneural protein indiscriminately. However, Le Dréau, Escalona et al. discovered that E proteins in fact have a much more active role to play. Using chick embryos, it was found that E proteins influence the way different proneural proteins bind to DNA. The E proteins have preferences for certain E-boxes in the DNA, just like proneural proteins do. The E proteins enhanced the activity of the proneural proteins that share their E-box preference, and reined in the activity of proneural proteins that prefer other E-boxes. As a result, the E proteins controlled the ability of these proteins to instruct neural progenitor cells to produce specific, specialized neurons, and thus ensured that the distinct types of neurons were produced in appropriate amounts. These findings will help shed light on the roles E proteins play in the development of the central nervous system, and the processes that control growth and lead to cell diversity. The results may also have applications in the field of regenerative medicine, as proneural proteins play an important role in cell reprogramming.
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Affiliation(s)
- Gwenvael Le Dréau
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - René Escalona
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Raquel Fueyo
- Department of Molecular Genomics, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Antonio Herrera
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Juan D Martínez
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Susana Usieto
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Anghara Menendez
- Department of Cell Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Sebastian Pons
- Department of Cell Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Marian A Martinez-Balbas
- Department of Molecular Genomics, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
| | - Elisa Marti
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Barcelona, Spain
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47
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Azzarelli R, Simons BD, Philpott A. The developmental origin of brain tumours: a cellular and molecular framework. Development 2018; 145:145/10/dev162693. [PMID: 29759978 PMCID: PMC6001369 DOI: 10.1242/dev.162693] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The development of the nervous system relies on the coordinated regulation of stem cell self-renewal and differentiation. The discovery that brain tumours contain a subpopulation of cells with stem/progenitor characteristics that are capable of sustaining tumour growth has emphasized the importance of understanding the cellular dynamics and the molecular pathways regulating neural stem cell behaviour. By focusing on recent work on glioma and medulloblastoma, we review how lineage tracing contributed to dissecting the embryonic origin of brain tumours and how lineage-specific mechanisms that regulate stem cell behaviour in the embryo may be subverted in cancer to achieve uncontrolled proliferation and suppression of differentiation. Summary: Lineage-tracing work in glioma and medulloblastoma reveals similarities between neuronal development and brain tumours, identifying potential new therapeutic avenues that exploit vulnerabilities in tumour growth patterns.
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Affiliation(s)
- Roberta Azzarelli
- Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge CB2 0XZ, UK.,Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.,Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - Benjamin D Simons
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.,The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.,Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - Anna Philpott
- Department of Oncology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge CB2 0XZ, UK .,Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
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Satou Y, Minami K, Hosono E, Okada H, Yasuoka Y, Shibano T, Tanaka T, Taira M. Phosphorylation states change Otx2 activity for cell proliferation and patterning in the Xenopus embryo. Development 2018; 145:dev.159640. [PMID: 29440302 DOI: 10.1242/dev.159640] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/01/2018] [Indexed: 12/19/2022]
Abstract
The homeodomain transcription factor Otx2 has essential roles in head and eye formation via the negative and positive regulation of its target genes, but it remains elusive how this dual activity of Otx2 affects cellular functions. In the current study, we first demonstrated that both exogenous and endogenous Otx2 are phosphorylated at multiple sites. Using Xenopus embryos, we identified three possible cyclin-dependent kinase (Cdk) sites and one Akt site, and analyzed the biological activities of phosphomimetic (4E) and nonphosphorylatable (4A) mutants for those sites. In the neuroectoderm, the 4E but not the 4A mutant downregulated the Cdk inhibitor gene p27xic1 (cdknx) and posterior genes, and promoted cell proliferation, possibly forming a positive-feedback loop consisting of Cdk, Otx2 and p27xic1 for cell proliferation, together with anteriorization. Conversely, the 4A mutant functioned as an activator on its own and upregulated the expression of eye marker genes, resulting in enlarged eyes. Consistent with these results, the interaction of Otx2 with the corepressor Tle1 is suggested to be phosphorylation dependent. These data suggest that Otx2 orchestrates cell proliferation, anteroposterior patterning and eye formation via its phosphorylation state.
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Affiliation(s)
- Yumeko Satou
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kohei Minami
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Erina Hosono
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hajime Okada
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuuri Yasuoka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.,Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Takashi Shibano
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiaki Tanaka
- Department of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Masanori Taira
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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Dennis DJ, Han S, Schuurmans C. bHLH transcription factors in neural development, disease, and reprogramming. Brain Res 2018; 1705:48-65. [PMID: 29544733 DOI: 10.1016/j.brainres.2018.03.013] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/07/2018] [Accepted: 03/10/2018] [Indexed: 01/16/2023]
Abstract
The formation of functional neural circuits in the vertebrate central nervous system (CNS) requires that appropriate numbers of the correct types of neuronal and glial cells are generated in their proper places and times during development. In the embryonic CNS, multipotent progenitor cells first acquire regional identities, and then undergo precisely choreographed temporal identity transitions (i.e. time-dependent changes in their identity) that determine how many neuronal and glial cells of each type they will generate. Transcription factors of the basic-helix-loop-helix (bHLH) family have emerged as key determinants of neural cell fate specification and differentiation, ensuring that appropriate numbers of specific neuronal and glial cell types are produced. Recent studies have further revealed that the functions of these bHLH factors are strictly regulated. Given their essential developmental roles, it is not surprising that bHLH mutations and de-regulated expression are associated with various neurological diseases and cancers. Moreover, the powerful ability of bHLH factors to direct neuronal and glial cell fate specification and differentiation has been exploited in the relatively new field of cellular reprogramming, in which pluripotent stem cells or somatic stem cells are converted to neural lineages, often with a transcription factor-based lineage conversion strategy that includes one or more of the bHLH genes. These concepts are reviewed herein.
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Affiliation(s)
- Daniel J Dennis
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N3M5, Canada
| | - Sisu Han
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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Abstract
Neural basic helix-loop helix (bHLH) transcription factors promote progenitor cell differentiation by activation of downstream target genes that coordinate neuronal differentiation. Here we characterize a neural bHLH target gene in Xenopus laevis, vexin (vxn; previously sbt1), that is homologous to human c8orf46 and is conserved across vertebrate species. C8orf46 has been implicated in cancer progression, but its function is unknown. Vxn is transiently expressed in differentiating progenitors in the developing central nervous system (CNS), and is required for neurogenesis in the neural plate and retina. Its function is conserved, since overexpression of either Xenopus or mouse vxn expands primary neurogenesis and promotes early retinal cell differentiation in cooperation with neural bHLH factors. Vxn protein is localized to the cell membrane and the nucleus, but functions in the nucleus to promote neural differentiation. Vxn inhibits cell proliferation, and works with the cyclin-dependent kinase inhibitor p27Xic1 (cdkn1b) to enhance neurogenesis and increase levels of the proneural protein Neurog2. We propose that vxn provides a key link between neural bHLH activity and execution of the neurogenic program.
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