1
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Rajan A, Fame RM. Brain development and bioenergetic changes. Neurobiol Dis 2024; 199:106550. [PMID: 38849103 DOI: 10.1016/j.nbd.2024.106550] [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: 04/15/2024] [Revised: 05/29/2024] [Accepted: 06/01/2024] [Indexed: 06/09/2024] Open
Abstract
Bioenergetics describe the biochemical processes responsible for energy supply in organisms. When these changes become dysregulated in brain development, multiple neurodevelopmental diseases can occur, implicating bioenergetics as key regulators of neural development. Historically, the discovery of disease processes affecting individual stages of brain development has revealed critical roles that bioenergetics play in generating the nervous system. Bioenergetic-dependent neurodevelopmental disorders include neural tube closure defects, microcephaly, intellectual disability, autism spectrum disorders, epilepsy, mTORopathies, and oncogenic processes. Developmental timing and cell-type specificity of these changes determine the long-term effects of bioenergetic disease mechanisms on brain form and function. Here, we discuss key metabolic regulators of neural progenitor specification, neuronal differentiation (neurogenesis), and gliogenesis. In general, transitions between glycolysis and oxidative phosphorylation are regulated in early brain development and in oncogenesis, and reactive oxygen species (ROS) and mitochondrial maturity play key roles later in differentiation. We also discuss how bioenergetics interface with the developmental regulation of other key neural elements, including the cerebrospinal fluid brain environment. While questions remain about the interplay between bioenergetics and brain development, this review integrates the current state of known key intersections between these processes in health and disease.
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Affiliation(s)
- Arjun Rajan
- Developmental Biology Graduate Program, Stanford University, Stanford, CA 94305, USA
| | - Ryann M Fame
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA.
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2
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Thor S. Indirect neurogenesis in space and time. Nat Rev Neurosci 2024; 25:519-534. [PMID: 38951687 DOI: 10.1038/s41583-024-00833-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 07/03/2024]
Abstract
During central nervous system (CNS) development, neural progenitor cells (NPCs) generate neurons and glia in two different ways. In direct neurogenesis, daughter cells differentiate directly into neurons or glia, whereas in indirect neurogenesis, neurons or glia are generated after one or more daughter cell divisions. Intriguingly, indirect neurogenesis is not stochastically deployed and plays instructive roles during CNS development: increased generation of cells from specific lineages; increased generation of early or late-born cell types within a lineage; and increased cell diversification. Increased indirect neurogenesis might contribute to the anterior CNS expansion evident throughout the Bilateria and help to modify brain-region size without requiring increased NPC numbers or extended neurogenesis. Increased indirect neurogenesis could be an evolutionary driver of the gyrencephalic (that is, folded) cortex that emerged during mammalian evolution and might even have increased during hominid evolution. Thus, selection of indirect versus direct neurogenesis provides a powerful developmental and evolutionary instrument that drives not only the evolution of CNS complexity but also brain expansion and modulation of brain-region size, and thereby the evolution of increasingly advanced cognitive abilities. This Review describes indirect neurogenesis in several model species and humans, and highlights some of the molecular genetic mechanisms that control this important process.
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Affiliation(s)
- Stefan Thor
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.
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3
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Nguyen PK, Cheng LY. Drosophila medulla neuroblast termination via apoptosis, differentiation, and gliogenic switch is scheduled by the depletion of the neuroepithelial stem cell pool. eLife 2024; 13:e96876. [PMID: 38905123 PMCID: PMC11262793 DOI: 10.7554/elife.96876] [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: 02/22/2024] [Accepted: 06/20/2024] [Indexed: 06/23/2024] Open
Abstract
The brain is consisted of diverse neurons arising from a limited number of neural stem cells. Drosophila neural stem cells called neuroblasts (NBs) produces specific neural lineages of various lineage sizes depending on their location in the brain. In the Drosophila visual processing centre - the optic lobes (OLs), medulla NBs derived from the neuroepithelium (NE) give rise to neurons and glia cells of the medulla cortex. The timing and the mechanisms responsible for the cessation of medulla NBs are so far not known. In this study, we show that the termination of medulla NBs during early pupal development is determined by the exhaustion of the NE stem cell pool. Hence, altering NE-NB transition during larval neurogenesis disrupts the timely termination of medulla NBs. Medulla NBs terminate neurogenesis via a combination of apoptosis, terminal symmetric division via Prospero, and a switch to gliogenesis via Glial Cell Missing (Gcm); however, these processes occur independently of each other. We also show that temporal progression of the medulla NBs is mostly not required for their termination. As the Drosophila OL shares a similar mode of division with mammalian neurogenesis, understanding when and how these progenitors cease proliferation during development can have important implications for mammalian brain size determination and regulation of its overall function.
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Affiliation(s)
- Phuong-Khanh Nguyen
- Peter MacCallum Cancer CentreMelbourneAustralia
- Department of Anatomy and Physiology, The University of MelbourneMelbourneAustralia
| | - Louise Y Cheng
- Peter MacCallum Cancer CentreMelbourneAustralia
- Department of Anatomy and Physiology, The University of MelbourneMelbourneAustralia
- Sir Peter MacCallum Department of Oncology, The University of MelbourneMelbourneAustralia
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4
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Rajan A, Anhezini L, Rives-Quinto N, Chhabra JY, Neville MC, Larson ED, Goodwin SF, Harrison MM, Lee CY. Low-level repressive histone marks fine-tune gene transcription in neural stem cells. eLife 2023; 12:e86127. [PMID: 37314324 PMCID: PMC10344426 DOI: 10.7554/elife.86127] [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: 01/11/2023] [Accepted: 06/11/2023] [Indexed: 06/15/2023] Open
Abstract
Coordinated regulation of gene activity by transcriptional and translational mechanisms poise stem cells for a timely cell-state transition during differentiation. Although important for all stemness-to-differentiation transitions, mechanistic understanding of the fine-tuning of gene transcription is lacking due to the compensatory effect of translational control. We used intermediate neural progenitor (INP) identity commitment to define the mechanisms that fine-tune stemness gene transcription in fly neural stem cells (neuroblasts). We demonstrate that the transcription factor FruitlessC (FruC) binds cis-regulatory elements of most genes uniquely transcribed in neuroblasts. Loss of fruC function alone has no effect on INP commitment but drives INP dedifferentiation when translational control is reduced. FruC negatively regulates gene expression by promoting low-level enrichment of the repressive histone mark H3K27me3 in gene cis-regulatory regions. Identical to fruC loss-of-function, reducing Polycomb Repressive Complex 2 activity increases stemness gene activity. We propose low-level H3K27me3 enrichment fine-tunes gene transcription in stem cells, a mechanism likely conserved from flies to humans.
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Affiliation(s)
- Arjun Rajan
- Life Sciences Institute, University of Michigan-Ann ArborAnn ArborUnited States
| | - Lucas Anhezini
- Life Sciences Institute, University of Michigan-Ann ArborAnn ArborUnited States
| | - Noemi Rives-Quinto
- Life Sciences Institute, University of Michigan-Ann ArborAnn ArborUnited States
| | - Jay Y Chhabra
- Life Sciences Institute, University of Michigan-Ann ArborAnn ArborUnited States
| | - Megan C Neville
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Elizabeth D Larson
- Department of Biomolecular Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Stephen F Goodwin
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Cheng-Yu Lee
- Life Sciences Institute, University of Michigan-Ann ArborAnn ArborUnited States
- Department of Cell and Developmental Biology, University of Michigan Medical SchoolAnn ArborUnited States
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan Medical SchoolAnn ArborUnited States
- Rogel Cancer Center, University of Michigan Medical SchoolAnn ArborUnited States
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5
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Antonica F, Aiello G, Soldano A, Abballe L, Miele E, Tiberi L. Modeling Brain Tumors: A Perspective Overview of in vivo and Organoid Models. Front Mol Neurosci 2022; 15:818696. [PMID: 35706426 PMCID: PMC9190727 DOI: 10.3389/fnmol.2022.818696] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/23/2022] [Indexed: 11/17/2022] Open
Abstract
Brain tumors are a large and heterogeneous group of neoplasms that affect the central nervous system and include some of the deadliest cancers. Almost all the conventional and new treatments fail to hinder tumoral growth of the most malignant brain tumors. This is due to multiple factors, such as intra-tumor heterogeneity, the microenvironmental properties of the human brain, and the lack of reliable models to test new therapies. Therefore, creating faithful models for each tumor and discovering tailored treatments pose great challenges in the fight against brain cancer. Over the years, different types of models have been generated, and, in this review, we investigated the advantages and disadvantages of the models currently used.
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Affiliation(s)
- Francesco Antonica
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Giuseppe Aiello
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Alessia Soldano
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Luana Abballe
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children’s Hospital, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS), Rome, Italy
| | - Evelina Miele
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children’s Hospital, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS), Rome, Italy
| | - Luca Tiberi
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
- *Correspondence: Luca Tiberi,
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6
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Havula E, Ghazanfar S, Lamichane N, Francis D, Hasygar K, Liu Y, Alton LA, Johnstone J, Needham EJ, Pulpitel T, Clark T, Niranjan HN, Shang V, Tong V, Jiwnani N, Audia G, Alves AN, Sylow L, Mirth C, Neely GG, Yang J, Hietakangas V, Simpson SJ, Senior AM. Genetic variation of macronutrient tolerance in Drosophila melanogaster. Nat Commun 2022; 13:1637. [PMID: 35347148 PMCID: PMC8960806 DOI: 10.1038/s41467-022-29183-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 02/28/2022] [Indexed: 11/08/2022] Open
Abstract
Carbohydrates, proteins and lipids are essential nutrients to all animals; however, closely related species, populations, and individuals can display dramatic variation in diet. Here we explore the variation in macronutrient tolerance in Drosophila melanogaster using the Drosophila genetic reference panel, a collection of ~200 strains derived from a single natural population. Our study demonstrates that D. melanogaster, often considered a "dietary generalist", displays marked genetic variation in survival on different diets, notably on high-sugar diet. Our genetic analysis and functional validation identify several regulators of macronutrient tolerance, including CG10960/GLUT8, Pkn and Eip75B. We also demonstrate a role for the JNK pathway in sugar tolerance and de novo lipogenesis. Finally, we report a role for tailless, a conserved orphan nuclear hormone receptor, in regulating sugar metabolism via insulin-like peptide secretion and sugar-responsive CCHamide-2 expression. Our study provides support for the use of nutrigenomics in the development of personalized nutrition.
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Affiliation(s)
- E Havula
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia.
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia.
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | - S Ghazanfar
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - N Lamichane
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - D Francis
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - K Hasygar
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Y Liu
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - L A Alton
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - J Johnstone
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - E J Needham
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - T Pulpitel
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - T Clark
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - H N Niranjan
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - V Shang
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - V Tong
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - N Jiwnani
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - G Audia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - A N Alves
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - L Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - C Mirth
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - G G Neely
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - J Yang
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Mathematics and Statistics, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - V Hietakangas
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - S J Simpson
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - A M Senior
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia.
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia.
- School of Mathematics and Statistics, The University of Sydney, Camperdown, NSW, 2006, Australia.
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7
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Chen R, Deng X, Zhu S. The Ets protein Pointed P1 represses Asense expression in type II neuroblasts by activating Tailless. PLoS Genet 2022; 18:e1009928. [PMID: 35100262 PMCID: PMC8830786 DOI: 10.1371/journal.pgen.1009928] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/10/2022] [Accepted: 01/20/2022] [Indexed: 12/03/2022] Open
Abstract
Intermediate neural progenitors (INPs) boost the number and diversity of neurons generated from neural stem cells (NSCs) by undergoing transient proliferation. In the developing Drosophila brains, INPs are generated from type II neuroblasts (NBs). In order to maintain type II NB identity and their capability to produce INPs, the proneural protein Asense (Ase) needs to be silenced by the Ets transcription factor pointed P1 (PntP1), a master regulator of type II NB development. However, the molecular mechanisms underlying the PntP1-mediated suppression of Ase is still unclear. In this study, we utilized genetic and molecular approaches to determine the transcriptional property of PntP1 and identify the direct downstream effector of PntP1 and the cis-DNA elements that mediate the suppression of ase. Our results demonstrate that PntP1 directly activates the expression of the transcriptional repressor, Tailless (Tll), by binding to seven Ets-binding sites, and Tll in turn suppresses the expression of Ase in type II NBs by binding to two hexameric core half-site motifs. We further show that Tll provides positive feedback to maintain the expression of PntP1 and the identity of type II NBs. Thus, our study identifies a novel direct target of PntP1 and reveals mechanistic details of the specification and maintenance of the type II NB identity by PntP1. Type II neuroblasts (NBs) are the neural stem cells (NSCs) in Drosophila central brains that produce neurons by generating intermediate neural progenitors (INPs) to boost brain complexity, as mammalian NSCs do during the development of neocortex. The key to the generation of INPs from type II NBs is the suppression of proneural protein Asense (Ase) in type II NBs by the Ets family transcription factor Pointed P1 (PntP1), but how PntP1 suppresses Ase expression remains unclear. In this study, we provided evidence to demonstrate that PntP1 directly activates the orphan nuclear receptor Tailless (Tll), which in turn suppresses Ase expression to maintain the capability of type II NBs to produce INPs. Meanwhile, Tll provides positive feedback to maintain the expression of PntP1 and type II NB identity. We further identified seven PntP1 binding sites in the tll enhancer regions and two Tll binding sites in the ase regulatory regions that mediate the activation of tll and the suppression of ase, respectively. Our work reveals detailed mechanisms of the specification and maintenance of the type II NB identity by PntP1.
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Affiliation(s)
- Rui Chen
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, United States of America
| | - Xiaobing Deng
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, United States of America
| | - Sijun Zhu
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, New York, United States of America
- * E-mail:
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8
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Larson ED, Komori H, Gibson TJ, Ostgaard CM, Hamm DC, Schnell JM, Lee CY, Harrison MM. Cell-type-specific chromatin occupancy by the pioneer factor Zelda drives key developmental transitions in Drosophila. Nat Commun 2021; 12:7153. [PMID: 34887421 PMCID: PMC8660810 DOI: 10.1038/s41467-021-27506-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022] Open
Abstract
During Drosophila embryogenesis, the essential pioneer factor Zelda defines hundreds of cis-regulatory regions and in doing so reprograms the zygotic transcriptome. While Zelda is essential later in development, it is unclear how the ability of Zelda to define cis-regulatory regions is shaped by cell-type-specific chromatin architecture. Asymmetric division of neural stem cells (neuroblasts) in the fly brain provide an excellent paradigm for investigating the cell-type-specific functions of this pioneer factor. We show that Zelda synergistically functions with Notch to maintain neuroblasts in an undifferentiated state. Zelda misexpression reprograms progenitor cells to neuroblasts, but this capacity is limited by transcriptional repressors critical for progenitor commitment. Zelda genomic occupancy in neuroblasts is reorganized as compared to the embryo, and this reorganization is correlated with differences in chromatin accessibility and cofactor availability. We propose that Zelda regulates essential transitions in the neuroblasts and embryo through a shared gene-regulatory network driven by cell-type-specific enhancers.
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Affiliation(s)
- Elizabeth D Larson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Hideyuki Komori
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tyler J Gibson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Cyrina M Ostgaard
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Danielle C Hamm
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Jack M Schnell
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Stem Cell and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Cheng-Yu Lee
- Division of Genetic Medicine, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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9
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Rajan A, Ostgaard CM, Lee CY. Regulation of Neural Stem Cell Competency and Commitment during Indirect Neurogenesis. Int J Mol Sci 2021; 22:12871. [PMID: 34884676 PMCID: PMC8657492 DOI: 10.3390/ijms222312871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022] Open
Abstract
Indirect neurogenesis, during which neural stem cells generate neurons through intermediate progenitors, drives the evolution of lissencephalic brains to gyrencephalic brains. The mechanisms that specify intermediate progenitor identity and that regulate stem cell competency to generate intermediate progenitors remain poorly understood despite their roles in indirect neurogenesis. Well-characterized lineage hierarchy and available powerful genetic tools for manipulating gene functions make fruit fly neural stem cell (neuroblast) lineages an excellent in vivo paradigm for investigating the mechanisms that regulate neurogenesis. Type II neuroblasts in fly larval brains repeatedly undergo asymmetric divisions to generate intermediate neural progenitors (INPs) that undergo limited proliferation to increase the number of neurons generated per stem cell division. Here, we review key regulatory genes and the mechanisms by which they promote the specification and generation of INPs, safeguarding the indirect generation of neurons during fly larval brain neurogenesis. Homologs of these regulators of INPs have been shown to play important roles in regulating brain development in vertebrates. Insight into the precise regulation of intermediate progenitors will likely improve our understanding of the control of indirect neurogenesis during brain development and brain evolution.
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Affiliation(s)
- Arjun Rajan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (A.R.); (C.M.O.)
| | - Cyrina M. Ostgaard
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (A.R.); (C.M.O.)
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Cheng-Yu Lee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (A.R.); (C.M.O.)
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Division of Genetic Medicine, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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10
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Majidi S, Ogilvie JM, Flaveny CA. Retinal Degeneration: Short-Term Options and Long-Term Vision for Future Therapy. MISSOURI MEDICINE 2021; 118:466-472. [PMID: 34658442 PMCID: PMC8504501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The leading cause blindness is the loss of retinal ganglion cells which connect the retina to the brain. Degenerative retinal diseases include retinal dystrophy, macular degeneration and diabetic retinopathy, which are currently incurable as the mammalian retina has no intrinsic regenerative capacity. By utilizing insight gained from retinal regeneration in simpler species we define an approach that may unlock regenerative programs in the mammalian retina that potentially facilitate the clinical restoration of retinal function.
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Affiliation(s)
- Shabnam Majidi
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Judith M Ogilvie
- Department of Biology; Saint Louis University School of Medicine, St. Louis, Missouri
| | - Colin A Flaveny
- Department of Biology; Saint Louis University School of Medicine, St. Louis, Missouri
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11
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Sheng C, Chen Z, Lei J, Zhu J, Song S. Development and Multi-Data Set Verification of an RNA Binding Protein Signature for Prognosis Prediction in Glioma. Front Med (Lausanne) 2021; 8:637803. [PMID: 33634155 PMCID: PMC7900154 DOI: 10.3389/fmed.2021.637803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/11/2021] [Indexed: 12/13/2022] Open
Abstract
Objective: Increasing evidence emphasizes the clinical implications of RNA binding proteins (RBPs) in cancers. This study aimed to develop a RBP signature for predicting prognosis in glioma. Methods: Two glioma datasets as training (n = 693) and validation (n = 325) sets were retrieved from the CGGA database. In the training set, univariate Cox regression analysis was conducted to screen prognosis-related RBPs based on differentially expressed RBPs between WHO grade II and IV. A ten-RBP signature was then established. The predictive efficacy was evaluated by ROCs. The applicability was verified in the validation set. The pathways involving the risk scores were analyzed by ssGSEA. scRNA-seq was utilized for evaluating their expression in different glioma cell types. Moreover, their expression was externally validated between glioma and control samples. Results: Based on 39 prognosis-related RBPs, a ten RBP signature was constructed. High risk score distinctly indicated a poorer prognosis than low risk score. AUCs were separately 0.838 and 0.822 in the training and validation sets, suggesting its well performance for prognosis prediction. Following adjustment of other clinicopathological characteristics, the signature was an independent risk factor. Various cancer-related pathways were significantly activated in samples with high risk score. The scRNA-seq identified that risk RBPs were mainly expressed in glioma malignant cells. Their high expression was also found in glioma than control samples. Conclusion: This study developed a novel RBP signature for robustly predicting prognosis of glioma following multi-data set verification. These RBPs may affect the progression of glioma.
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Affiliation(s)
- Chunpeng Sheng
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Zhihua Chen
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jianwei Lei
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jianming Zhu
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Shuxin Song
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
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12
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Rives-Quinto N, Komori H, Ostgaard CM, Janssens DH, Kondo S, Dai Q, Moore AW, Lee CY. Sequential activation of transcriptional repressors promotes progenitor commitment by silencing stem cell identity genes. eLife 2020; 9:e56187. [PMID: 33241994 PMCID: PMC7728440 DOI: 10.7554/elife.56187] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 11/25/2020] [Indexed: 12/21/2022] Open
Abstract
Stem cells that indirectly generate differentiated cells through intermediate progenitors drives vertebrate brain evolution. Due to a lack of lineage information, how stem cell functionality, including the competency to generate intermediate progenitors, becomes extinguished during progenitor commitment remains unclear. Type II neuroblasts in fly larval brains divide asymmetrically to generate a neuroblast and a progeny that commits to an intermediate progenitor (INP) identity. We identified Tailless (Tll) as a master regulator of type II neuroblast functional identity, including the competency to generate INPs. Successive expression of transcriptional repressors functions through Hdac3 to silence tll during INP commitment. Reducing repressor activity allows re-activation of Notch in INPs to ectopically induce tll expression driving supernumerary neuroblast formation. Knocking-down hdac3 function prevents downregulation of tll during INP commitment. We propose that continual inactivation of stem cell identity genes allows intermediate progenitors to stably commit to generating diverse differentiated cells during indirect neurogenesis.
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Affiliation(s)
| | - Hideyuki Komori
- Life Sciences Institute, University of MichiganAnn ArborUnited States
| | - Cyrina M Ostgaard
- Life Sciences Institute, University of MichiganAnn ArborUnited States
- Department of Cell and Developmental Biology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Derek H Janssens
- Life Sciences Institute, University of MichiganAnn ArborUnited States
| | - Shu Kondo
- Invertebrate Genetics Laboratory, National Institute of GeneticsMishimaJapan
| | - Qi Dai
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm UniversityStockholmSweden
| | | | - Cheng-Yu Lee
- Life Sciences Institute, University of MichiganAnn ArborUnited States
- Department of Cell and Developmental Biology, University of Michigan Medical SchoolAnn ArborUnited States
- Division of Genetic Medicine, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan Medical SchoolAnn ArborUnited States
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