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McEwan F, Glazier JD, Hager R. The impact of maternal immune activation on embryonic brain development. Front Neurosci 2023; 17:1146710. [PMID: 36950133 PMCID: PMC10025352 DOI: 10.3389/fnins.2023.1146710] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/15/2023] [Indexed: 03/08/2023] Open
Abstract
The adult brain is a complex structure with distinct functional sub-regions, which are generated from an initial pool of neural epithelial cells within the embryo. This transition requires a number of highly coordinated processes, including neurogenesis, i.e., the generation of neurons, and neuronal migration. These take place during a critical period of development, during which the brain is particularly susceptible to environmental insults. Neurogenesis defects have been associated with the pathogenesis of neurodevelopmental disorders (NDDs), such as autism spectrum disorder and schizophrenia. However, these disorders have highly complex multifactorial etiologies, and hence the underlying mechanisms leading to aberrant neurogenesis continue to be the focus of a significant research effort and have yet to be established. Evidence from epidemiological studies suggests that exposure to maternal infection in utero is a critical risk factor for NDDs. To establish the biological mechanisms linking maternal immune activation (MIA) and altered neurodevelopment, animal models have been developed that allow experimental manipulation and investigation of different developmental stages of brain development following exposure to MIA. Here, we review the changes to embryonic brain development focusing on neurogenesis, neuronal migration and cortical lamination, following MIA. Across published studies, we found evidence for an acute proliferation defect in the embryonic MIA brain, which, in most cases, is linked to an acceleration in neurogenesis, demonstrated by an increased proportion of neurogenic to proliferative divisions. This is accompanied by disrupted cortical lamination, particularly in the density of deep layer neurons, which may be a consequence of the premature neurogenic shift. Although many aspects of the underlying pathways remain unclear, an altered epigenome and mitochondrial dysfunction are likely mechanisms underpinning disrupted neurogenesis in the MIA model. Further research is necessary to delineate the causative pathways responsible for the variation in neurogenesis phenotype following MIA, which are likely due to differences in timing of MIA induction as well as sex-dependent variation. This will help to better understand the underlying pathogenesis of NDDs, and establish therapeutic targets.
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2
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Sachana M, Willett C, Pistollato F, Bal-Price A. The potential of mechanistic information organised within the AOP framework to increase regulatory uptake of the developmental neurotoxicity (DNT) in vitro battery of assays. Reprod Toxicol 2021; 103:159-170. [PMID: 34147625 PMCID: PMC8279093 DOI: 10.1016/j.reprotox.2021.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/19/2021] [Accepted: 06/04/2021] [Indexed: 12/24/2022]
Abstract
Current in vivo DNT testing for regulatory purposes is not effective. In vitro assays anchored to key neurodevelopmental processes are available. Development of Adverse Outcome Pathways is required to increase mechanistic understanding of DNT effects. DNT Integrated Approaches to Testing and Assessment for various regulatory purposes should be developed. The OECD Guidance Document on use of in vitro DNT battery of assays is currently under development.
A major challenge in regulatory developmental neurotoxicity (DNT) assessment is lack of toxicological information for many compounds. Therefore, the Test Guidelines programme of the Organisation for Economic Cooperation and Development (OECD) took the initiative to coordinate an international collaboration between diverse stakeholders to consider integration of alternative approaches towards improving the current chemical DNT testing. During the past few years, a series of workshops was organized during which a consensus was reached that incorporation of a DNT testing battery that relies on in vitro assays anchored to key neurodevelopmental processes should be developed. These key developmental processes include neural progenitor cell proliferation, neuronal and oligodendrocyte differentiation, neural cell migration, neurite outgrowth, synaptogenesis and neuronal network formation, as well key events identified in the existing Adverse Outcome Pathways (AOPs). AOPs deliver mechanistic information on the causal links between molecular initiating event, intermediate key events and an adverse outcome of regulatory concern, providing the biological context to facilitate development of Integrated Approaches to Testing and Assessment (IATA) for various regulatory purposes. Developing IATA case studies, using mechanistic information derived from AOPs, is expected to increase scientific confidence for the use of in vitro methods within an IATA, thereby facilitating regulatory uptake. This manuscript summarizes the current state of international efforts to enhance DNT testing by using an in vitro battery of assays focusing on the role of AOPs in informing the development of IATA for different regulatory purposes, aiming to deliver an OECD guidance document on use of in vitro DNT battery of assays that include in vitro data interpretation.
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Affiliation(s)
- Magdalini Sachana
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Co-Operation and Development (OECD), 75775, Paris Cedex 16, France
| | - Catherine Willett
- Humane Society International, 1255 23rd Street NW, Washington, DC, 20037, USA
| | | | - Anna Bal-Price
- European Commission Joint Research Centre (JRC), Ispra, Italy.
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3
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Lybrand ZR, Goswami S, Zhu J, Jarzabek V, Merlock N, Aktar M, Smith C, Zhang L, Varma P, Cho KO, Ge S, Hsieh J. A critical period of neuronal activity results in aberrant neurogenesis rewiring hippocampal circuitry in a mouse model of epilepsy. Nat Commun 2021; 12:1423. [PMID: 33658509 PMCID: PMC7930276 DOI: 10.1038/s41467-021-21649-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 02/04/2021] [Indexed: 01/31/2023] Open
Abstract
In the mammalian hippocampus, adult-born granule cells (abGCs) contribute to the function of the dentate gyrus (DG). Disruption of the DG circuitry causes spontaneous recurrent seizures (SRS), which can lead to epilepsy. Although abGCs contribute to local inhibitory feedback circuitry, whether they are involved in epileptogenesis remains elusive. Here, we identify a critical window of activity associated with the aberrant maturation of abGCs characterized by abnormal dendrite morphology, ectopic migration, and SRS. Importantly, in a mouse model of temporal lobe epilepsy, silencing aberrant abGCs during this critical period reduces abnormal dendrite morphology, cell migration, and SRS. Using mono-synaptic tracers, we show silencing aberrant abGCs decreases recurrent CA3 back-projections and restores proper cortical connections to the hippocampus. Furthermore, we show that GABA-mediated amplification of intracellular calcium regulates the early critical period of activity. Our results demonstrate that aberrant neurogenesis rewires hippocampal circuitry aggravating epilepsy in mice.
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Affiliation(s)
- Zane R Lybrand
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
- Department of Biology, Texas Woman's University, Denton, TX, USA
| | - Sonal Goswami
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Jingfei Zhu
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Veronica Jarzabek
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Nikolas Merlock
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Mahafuza Aktar
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Courtney Smith
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Ling Zhang
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Parul Varma
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Kyung-Ok Cho
- Department of Pharmacology, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea
- Department of Biomedicine & Health Sciences, Institute of Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Shaoyu Ge
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Jenny Hsieh
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA.
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA.
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Abstract
Neuronal migration is a fundamental brain development process that allows cells to move from their birthplaces to their sites of integration. Although neuronal migration largely ceases during embryonic and early postnatal development, neuroblasts continue to be produced and to migrate to a few regions of the adult brain such as the dentate gyrus and the subventricular zone (SVZ). In the SVZ, a large number of neuroblasts migrate into the olfactory bulb (OB) along the rostral migratory stream (RMS). Neuroblasts migrate in chains in a tightly organized micro-environment composed of astrocytes that ensheath the chains of neuroblasts and regulate their migration; the blood vessels that are used by neuroblasts as a physical scaffold and a source of molecular factors; and axons that modulate neuronal migration. In addition to diverse sets of extrinsic micro-environmental cues, long-distance neuronal migration involves a number of intrinsic mechanisms, including membrane and cytoskeleton remodeling, Ca2+ signaling, mitochondria dynamics, energy consumption, and autophagy. All these mechanisms are required to cope with the different micro-environment signals and maintain cellular homeostasis in order to sustain the proper dynamics of migrating neuroblasts and their faithful arrival in the target regions. Neuroblasts in the postnatal brain not only migrate into the OB but may also deviate from their normal path to migrate to a site of injury induced by a stroke or by certain neurodegenerative disorders. In this review, we will focus on the intrinsic mechanisms that regulate long-distance neuroblast migration in the adult brain and on how these pathways may be modulated to control the recruitment of neuroblasts to damaged/diseased brain areas.
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Affiliation(s)
- Cedric Bressan
- CERVO Brain Research Center, Quebec City, QC, Canada.,Department of Psychiatry and Neuroscience, Université Laval, Quebec City, QC, Canada
| | - Armen Saghatelyan
- CERVO Brain Research Center, Quebec City, QC, Canada.,Department of Psychiatry and Neuroscience, Université Laval, Quebec City, QC, Canada
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5
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Zhou ZW, Kirtay M, Schneble N, Yakoub G, Ding M, Rüdiger T, Siniuk K, Lu R, Jiang YN, Li TL, Kaether C, Barzilai A, Wang ZQ. NBS1 interacts with Notch signaling in neuronal homeostasis. Nucleic Acids Res 2020; 48:10924-10939. [PMID: 33010171 PMCID: PMC7641754 DOI: 10.1093/nar/gkaa716] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/03/2020] [Accepted: 08/24/2020] [Indexed: 12/15/2022] Open
Abstract
NBS1 is a critical component of the MRN (MRE11/RAD50/NBS1) complex, which regulates ATM- and ATR-mediated DNA damage response (DDR) pathways. Mutations in NBS1 cause the human genomic instability syndrome Nijmegen Breakage Syndrome (NBS), of which neuronal deficits, including microcephaly and intellectual disability, are classical hallmarks. Given its function in the DDR to ensure proper proliferation and prevent death of replicating cells, NBS1 is essential for life. Here we show that, unexpectedly, Nbs1 deletion is dispensable for postmitotic neurons, but compromises their arborization and migration due to dysregulated Notch signaling. We find that Nbs1 interacts with NICD-RBPJ, the effector of Notch signaling, and inhibits Notch activity. Genetic ablation or pharmaceutical inhibition of Notch signaling rescues the maturation and migration defects of Nbs1-deficient neurons in vitro and in vivo. Upregulation of Notch by Nbs1 deletion is independent of the key DDR downstream effector p53 and inactivation of each MRN component produces a different pattern of Notch activity and distinct neuronal defects. These data indicate that neuronal defects and aberrant Notch activity in Nbs1-deficient cells are unlikely to be a direct consequence of loss of MRN-mediated DDR function. This study discloses a novel function of NBS1 in crosstalk with the Notch pathway in neuron development.
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Affiliation(s)
- Zhong-Wei Zhou
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany.,School of Medicine (Shenzhen), Sun Yat-Sen University, Guangzhou, China
| | - Murat Kirtay
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - Nadine Schneble
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - George Yakoub
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - Mingmei Ding
- School of Medicine (Shenzhen), Sun Yat-Sen University, Guangzhou, China
| | - Tina Rüdiger
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - Kanstantsin Siniuk
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - Ruiqing Lu
- School of Medicine (Shenzhen), Sun Yat-Sen University, Guangzhou, China
| | - Yi-Nan Jiang
- School of Medicine (Shenzhen), Sun Yat-Sen University, Guangzhou, China
| | - Tang-Liang Li
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany.,Institute of Aging Research, School of Medicine, Hangzhou Normal University, Hangzhou, China
| | - Christoph Kaether
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
| | - Ari Barzilai
- Department of Neurobiology, George S. Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Zhao-Qi Wang
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany.,Faculty of Biological Sciences, Friedrich-Schiller-University Jena, Jena, Germany
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Haddad-Tóvolli R, Altirriba J, Obri A, Sánchez EE, Chivite I, Milà-Guasch M, Ramírez S, Gómez-Valadés AG, Pozo M, Burguet J, Velloso LA, Claret M. Pro-opiomelanocortin (POMC) neuron translatome signatures underlying obesogenic gestational malprogramming in mice. Mol Metab 2020; 36:100963. [PMID: 32283518 PMCID: PMC7152705 DOI: 10.1016/j.molmet.2020.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE Maternal unbalanced nutritional habits during embryonic development and perinatal stages perturb hypothalamic neuronal programming of the offspring, thus increasing obesity-associated diabetes risk. However, the underlying molecular mechanisms remain largely unknown. In this study we sought to determine the translatomic signatures associated with pro-opiomelanocortin (POMC) neuron malprogramming in maternal obesogenic conditions. METHODS We used the RiboTag mouse model to specifically profile the translatome of POMC neurons during neonatal (P0) and perinatal (P21) life and its neuroanatomical, functional, and physiological consequences. RESULTS Maternal high-fat diet (HFD) exposure did not interfere with offspring's hypothalamic POMC neuron specification, but significantly impaired their spatial distribution and axonal extension to target areas. Importantly, we established POMC neuron-specific translatome signatures accounting for aberrant neuronal development and axonal growth. These anatomical and molecular alterations caused metabolic dysfunction in early life and adulthood. CONCLUSIONS Our study provides fundamental insights on the molecular mechanisms underlying POMC neuron malprogramming in obesogenic contexts.
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Affiliation(s)
- Roberta Haddad-Tóvolli
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Jordi Altirriba
- Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
| | - Arnaud Obri
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Elena Eyre Sánchez
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Iñigo Chivite
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Maria Milà-Guasch
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Sara Ramírez
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Alicia G Gómez-Valadés
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Macarena Pozo
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Jasmine Burguet
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000, Versailles, France.
| | - Licio A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Brazil.
| | - Marc Claret
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain; School of Medicine, Universitat de Barcelona, Barcelona, Spain.
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7
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Korshunova I, Rhein S, García-González D, Stölting I, Pfisterer U, Barta A, Dmytriyeva O, Kirkeby A, Schwaninger M, Khodosevich K. Genetic modification increases the survival and the neuroregenerative properties of transplanted neural stem cells. JCI Insight 2020; 5:126268. [PMID: 31999645 DOI: 10.1172/jci.insight.126268] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/22/2020] [Indexed: 12/24/2022] Open
Abstract
Cell therapy raises hopes high for better treatment of brain disorders. However, the majority of transplanted cells often die soon after transplantation, and those that survive initially continue to die in the subacute phase, diminishing the impact of transplantations. In this study, we genetically modified transplanted human neural stem cells (hNSCs), from 2 distant embryonic stem cell lines (H9 and RC17), to express 1 of 4 prosurvival factors - Hif1a, Akt1, Bcl-2, or Bcl-xl - and studied how these modifications improve short- and long-term survival of transplanted hNSCs. All genetic modifications dramatically increased survival of the transplanted hNSCs. Importantly, 3 out of 4 modifications also enhanced the exit of hNSCs from the cell cycle, thus avoiding aberrant growth of the transplants. Bcl-xl expression provided the strongest protection of transplanted cells, reducing both immediate and delayed cell death, and stimulated hNSC differentiation toward neuronal and oligodendroglial lineages. By designing hNSCs with drug-controlled expression of Bcl-xl, we demonstrated that short-term expression of a prosurvival factor can ensure the long-term survival of transplanted cells. Importantly, transplantation of Bcl-xl-expressing hNSCs into mice suffering from stroke improved behavioral outcome and recovery of motor activity in mice.
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Affiliation(s)
- Irina Korshunova
- Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Sina Rhein
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | | | - Ines Stölting
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Ulrich Pfisterer
- Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Anna Barta
- Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Oksana Dmytriyeva
- Department of Biomedical Sciences.,Novo Nordisk Foundation Center for Basic Metabolic Research, and
| | - Agnete Kirkeby
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Experimental Medical Science and Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
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8
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Abstract
Migration of neurons starts in the prenatal period and continues into infancy. This developmental process is crucial for forming a proper neuronal network, and the disturbance of this process results in dysfunction of the brain such as epilepsy. Prenatal exposure to environmental stress, including alcohol, drugs, and inflammation, disrupts neuronal migration and causes neuronal migration disorders (NMDs). In this review, we summarize recent findings on this topic and specifically focusing on two different modes of migration, radial, and tangential migration during cortical development. The shared mechanisms underlying the NMDs are discussed by comparing the molecular changes in impaired neuronal migration under exposure to different types of prenatal environmental stress.
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Affiliation(s)
- Hye M Hwang
- Center for Neuroscience Research, Children's National Medical Center, The Children's Research Institute, Washington, DC, United States.,The Institute for Biomedical Sciences, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
| | - Ray Y Ku
- Center for Neuroscience Research, Children's National Medical Center, The Children's Research Institute, Washington, DC, United States
| | - Kazue Hashimoto-Torii
- Center for Neuroscience Research, Children's National Medical Center, The Children's Research Institute, Washington, DC, United States.,Departments of Pediatrics, and Pharmacology & Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
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9
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Abstract
Background Differential gene expression analysis using RNA-seq data is a popular approach for discovering specific regulation mechanisms under certain environmental settings. Both gene ontology (GO) and KEGG pathway enrichment analysis are major processes for investigating gene groups that participate in common biological responses or possess related functions. However, traditional approaches based on differentially expressed genes only detect a few significant GO terms and pathways, which are frequently insufficient to explain all-inclusive gene regulation mechanisms. Methods Transcriptomes of survivin (birc5) gene knock-down experimental and wild-type control zebrafish embryos were sequenced and assembled, and a differential expression (DE) gene list was obtained for traditional functional enrichment analysis. In addition to including DE genes with significant fold-change levels, we considered additional associated genes near or overlapped with differentially expressed long noncoding RNAs (DE lncRNAs), which may directly or indirectly activate or inhibit target genes and play important roles in regulation networks. Both the original DE gene list and the additional DE lncRNA-associated genes were combined to perform a comprehensive overrepresentation analysis. Results In this study, a total of 638 DE genes and 616 DE lncRNA-associated genes (lncGenes) were leveraged simultaneously in searching for significant GO terms and KEGG pathways. Compared to the traditional approach of only using a differential expression gene list, the proposed method of employing DE lncRNA-associated genes identified several additional important GO terms and KEGG pathways. In GO enrichment analysis, 60% more GO terms were obtained, and several neuron development functional terms were retrieved as complete annotations. We also observed that additional important pathways such as the FoxO and MAPK signaling pathways were retrieved, which were shown in previous reports to play important roles in apoptosis and neuron development functions regulated by the survivin gene. Conclusions We demonstrated that incorporating genes near or overlapped with DE lncRNAs into the DE gene list outperformed the traditional enrichment analysis method for effective biological functional interpretations. These hidden interactions between lncRNAs and target genes could facilitate more comprehensive analyses.
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Affiliation(s)
- Kuo-Sheng Hung
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Chung-Chi Hsiao
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Tun-Wen Pai
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan.
| | - Chin-Hwa Hu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.,Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Wen-Shyong Tzou
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.,Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Wen-Der Wang
- Department of Bioagricultural Science, National Chiayi University, Chiayi, Taiwan
| | - Yet-Ran Chen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
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10
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Barry KM, Dinan TG, Stanton C, Kelly PM. Investigation of the neurotrophic effect of dairy phospholipids on cortical neuron outgrowth and stimulation. J Funct Foods 2018; 40:60-7. [DOI: 10.1016/j.jff.2017.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Pfisterer U, Khodosevich K. Neuronal survival in the brain: neuron type-specific mechanisms. Cell Death Dis 2017; 8:e2643. [PMID: 28252642 PMCID: PMC5386560 DOI: 10.1038/cddis.2017.64] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 01/24/2017] [Accepted: 01/31/2017] [Indexed: 12/19/2022]
Abstract
Neurogenic regions of mammalian brain produce many more neurons that will eventually survive and reach a mature stage. Developmental cell death affects both embryonically produced immature neurons and those immature neurons that are generated in regions of adult neurogenesis. Removal of substantial numbers of neurons that are not yet completely integrated into the local circuits helps to ensure that maturation and homeostatic function of neuronal networks in the brain proceed correctly. External signals from brain microenvironment together with intrinsic signaling pathways determine whether a particular neuron will die. To accommodate this signaling, immature neurons in the brain express a number of transmembrane factors as well as intracellular signaling molecules that will regulate the cell survival/death decision, and many of these factors cease being expressed upon neuronal maturation. Furthermore, pro-survival factors and intracellular responses depend on the type of neuron and region of the brain. Thus, in addition to some common neuronal pro-survival signaling, different types of neurons possess a variety of 'neuron type-specific' pro-survival constituents that might help them to adapt for survival in a certain brain region. This review focuses on how immature neurons survive during normal and impaired brain development, both in the embryonic/neonatal brain and in brain regions associated with adult neurogenesis, and emphasizes neuron type-specific mechanisms that help to survive for various types of immature neurons. Importantly, we mainly focus on in vivo data to describe neuronal survival specifically in the brain, without extrapolating data obtained in the PNS or spinal cord, and thus emphasize the influence of the complex brain environment on neuronal survival during development.
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Affiliation(s)
- Ulrich Pfisterer
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Konstantin Khodosevich
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
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12
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Bahmad H, Hadadeh O, Chamaa F, Cheaito K, Darwish B, Makkawi AK, Abou-Kheir W. Modeling Human Neurological and Neurodegenerative Diseases: From Induced Pluripotent Stem Cells to Neuronal Differentiation and Its Applications in Neurotrauma. Front Mol Neurosci 2017; 10:50. [PMID: 28293168 PMCID: PMC5329035 DOI: 10.3389/fnmol.2017.00050] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/13/2017] [Indexed: 12/14/2022] Open
Abstract
With the help of several inducing factors, somatic cells can be reprogrammed to become induced pluripotent stem cell (iPSCs) lines. The success is in obtaining iPSCs almost identical to embryonic stem cells (ESCs), therefore various approaches have been tested and ultimately several ones have succeeded. The importance of these cells is in how they serve as models to unveil the molecular pathways and mechanisms underlying several human diseases, and also in its potential roles in the development of regenerative medicine. They further aid in the development of regenerative medicine, autologous cell therapy and drug or toxicity screening. Here, we provide a comprehensive overview of the recent development in the field of iPSCs research, specifically for modeling human neurological and neurodegenerative diseases, and its applications in neurotrauma. These are mainly characterized by progressive functional or structural neuronal loss rendering them extremely challenging to manage. Many of these diseases, including Parkinson's disease (PD), Huntington's disease (HD), Amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD) have been explored in vitro. The main purpose is to generate patient-specific iPS cell lines from the somatic cells that carry mutations or genetic instabilities for the aim of studying their differentiation potential and behavior. This new technology will pave the way for future development in the field of stem cell research anticipating its use in clinical settings and in regenerative medicine in order to treat various human diseases, including neurological and neurodegenerative diseases.
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Affiliation(s)
| | | | | | | | | | | | - Wassim Abou-Kheir
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of BeirutBeirut, Lebanon
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Unachukwu UJ, Warren A, Li Z, Mishra S, Zhou J, Sauane M, Lim H, Vazquez M, Redenti S. Predicted molecular signaling guiding photoreceptor cell migration following transplantation into damaged retina. Sci Rep 2016; 6:22392. [PMID: 26935401 PMCID: PMC4776098 DOI: 10.1038/srep22392] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/11/2016] [Indexed: 12/18/2022] Open
Abstract
To replace photoreceptors lost to disease or trauma and restore vision, laboratories around the world are investigating photoreceptor replacement strategies using subretinal transplantation of photoreceptor precursor cells (PPCs) and retinal progenitor cells (RPCs). Significant obstacles to advancement of photoreceptor cell-replacement include low migration rates of transplanted cells into host retina and an absence of data describing chemotactic signaling guiding migration of transplanted cells in the damaged retinal microenvironment. To elucidate chemotactic signaling guiding transplanted cell migration, bioinformatics modeling of PPC transplantation into light-damaged retina was performed. The bioinformatics modeling analyzed whole-genome expression data and matched PPC chemotactic cell-surface receptors to cognate ligands expressed in the light-damaged retinal microenvironment. A library of significantly predicted chemotactic ligand-receptor pairs, as well as downstream signaling networks was generated. PPC and RPC migration in microfluidic ligand gradients were analyzed using a highly predicted ligand-receptor pair, SDF-1α – CXCR4, and both PPCs and RPCs exhibited significant chemotaxis. This work present a systems level model and begins to elucidate molecular mechanisms involved in PPC and RPC migration within the damaged retinal microenvironment.
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Affiliation(s)
- Uchenna John Unachukwu
- Biochemistry Doctoral Program, The Graduate School, City University of New York, New York, NY, USA.,Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA
| | - Alice Warren
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA
| | - Ze Li
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA
| | - Shawn Mishra
- Department of Biomedical Engineering, City College of New York, City University of New York, NY, USA
| | - Jing Zhou
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA.,Neuroscience Doctoral Program, The Graduate School, City University of New York, New York, NY, USA
| | - Moira Sauane
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA
| | - Hyungsik Lim
- Departments of Physics and Biology, Hunter College of the City University of New York, New York, NY USA
| | - Maribel Vazquez
- Department of Biomedical Engineering, City College of New York, City University of New York, NY, USA
| | - Stephen Redenti
- Biochemistry Doctoral Program, The Graduate School, City University of New York, New York, NY, USA.,Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA
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14
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Unachukwu UJ, Sauane M, Vazquez M, Redenti S. Microfluidic generated EGF-gradients induce chemokinesis of transplantable retinal progenitor cells via the JAK/STAT and PI3kinase signaling pathways. PLoS One 2013; 8:e83906. [PMID: 24376770 PMCID: PMC3871684 DOI: 10.1371/journal.pone.0083906] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 11/10/2013] [Indexed: 11/18/2022] Open
Abstract
A growing number of studies are evaluating retinal progenitor cell (RPC) transplantation as an approach to repair retinal degeneration and restore visual function. To advance cell-replacement strategies for a practical retinal therapy, it is important to define the molecular and biochemical mechanisms guiding RPC motility. We have analyzed RPC expression of the epidermal growth factor receptor (EGFR) and evaluated whether exposure to epidermal growth factor (EGF) can coordinate motogenic activity in vitro. Using Boyden chamber analysis as an initial high-throughput screen, we determined that RPC motility was optimally stimulated by EGF concentrations in the range of 20-400 ng/ml, with decreased stimulation at higher concentrations, suggesting concentration-dependence of EGF-induced motility. Using bioinformatics analysis of the EGF ligand in a retina-specific gene network pathway, we predicted a chemotactic function for EGF involving the MAPK and JAK-STAT intracellular signaling pathways. Based on targeted inhibition studies, we show that ligand binding, phosphorylation of EGFR and activation of the intracellular STAT3 and PI3kinase signaling pathways are necessary to drive RPC motility. Using engineered microfluidic devices to generate quantifiable steady-state gradients of EGF coupled with live-cell tracking, we analyzed the dynamics of individual RPC motility. Microfluidic analysis, including center of mass and maximum accumulated distance, revealed that EGF induced motility is chemokinetic with optimal activity observed in response to low concentration gradients. Our combined results show that EGFR expressing RPCs exhibit enhanced chemokinetic motility in the presence of low nanomole levels of EGF. These findings may serve to inform further studies evaluating the extent to which EGFR activity, in response to endogenous ligand, drives motility and migration of RPCs in retinal transplantation paradigms.
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Affiliation(s)
- Uchenna J. Unachukwu
- Biochemistry Doctoral Program, The Graduate School and University Center, City University of New York, New York, New York, United States of America
| | - Moira Sauane
- Department of Biological Sciences, Herbert Lehman College, City University of New York, Bronx, New York, United States of America
| | - Maribel Vazquez
- Department of Biomedical Engineering, City College of New York, City University of New York, New York, New York, United States of America
| | - Stephen Redenti
- Biochemistry Doctoral Program, The Graduate School and University Center, City University of New York, Department of Biological Sciences, Herbert Lehman College, City University of New York, Bronx, New York, United States of America
- * E-mail:
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Abstract
NeuroD is required for the survival of many subtypes of developing neurons in the vertebrate central nervous system. Because NeuroD-deficient neurons in the hippocampus, cerebellum, and inner ear die prematurely in the early stage of neurogenesis, the role of NeuroD during the later stages of neurogenesis of these cell subtypes is not well understood. In addition, the mechanism of NeuroDdeficient neuronal death has not been investigated. It was hypothesized that NeuroD-dependent neuronal death occurs through a Bax-dependent apoptotic pathway. Based on this hypothesis, this study attempted to rescue neuronal cell death by deleting the Bax gene in NeuroD null mice to investigate the role of NeuroD in surviving neurons. The NeuroD and Bax double null mice displayed a decrease in the number of apoptotic cells in the hippocampus and the cerebellum and the rescue of vestibulocochlear ganglion (VCG) neurons that failed to migrate and innervate. In addition, at E13.5, the NeuroD(-/-)Bax(-/-) VCG neurons failed to express TrkB and TrkC, which are known to be essential for the survival of those neurons. These data suggest that neuronal death in NeuroD null mice is mediated by Bax-dependent apoptosis and that NeuroD is required for the migration of VCG neurons. Finally, these data show that TrkB and TrkC expression in E13.5 VCG neurons requires NeuroD and that TrkB and TrkC expression may be necessary for the normal migration and innervations of those neurons.
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Affiliation(s)
- Woo-Young Kim
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Aurora, CO, 80309, USA.
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Khodosevich K, Alfonso J, Monyer H. Dynamic changes in the transcriptional profile of subventricular zone-derived postnatally born neuroblasts. Mech Dev 2013; 130:424-32. [PMID: 23220001 DOI: 10.1016/j.mod.2012.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 11/06/2012] [Accepted: 11/12/2012] [Indexed: 02/07/2023]
Abstract
The subventricular zone (SVZ) of the lateral ventricles is a major neurogenic region in the postnatal mammalian brain. Thousands of neuroblasts are generated daily throughout the life of an animal. Newly born neuroblasts migrate via the rostral migratory stream (RMS) into the olfactory bulb where they mature into distinct neuronal subtypes. Neuroblasts exiting the SVZ retain the ability to proliferate, however, proliferation declines in the course of migration to the olfactory bulb. While migrating in the RMS, neuroblasts receive a plethora of stimuli that modify transcription according to the local microenvironment, and eventually modulate neuroblast migration. In the target area, the olfactory bulb, neuroblasts develop into mature neurons. In this review, we discuss dynamic changes of the transcriptome that occur during the "lifetime" of a neuroblast, thereby governing the activation or inhibition of distinct genes/pathways that are responsible for proliferation, migration and differentiation.
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Khodosevich K, Zuccotti A, Kreuzberg MM, Le Magueresse C, Frank M, Willecke K, Monyer H. Connexin45 modulates the proliferation of transit-amplifying precursor cells in the mouse subventricular zone. Proc Natl Acad Sci U S A 2012; 109:20107-12. [PMID: 23169657 DOI: 10.1073/pnas.1217103109] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Connexins have been implicated in the regulation of precursor cell migration and proliferation during embryonic development of the mammalian brain. However, their function in postnatal neurogenesis is unclear. Here we demonstrate that connexin (Cx) 45 is expressed in transit-amplifying cells and neuroblasts in the postnatal subventricular zone (SVZ) and modulated the proliferation of SVZ-derived precursor cells in vivo. Thus, overexpression of Cx45 by retroviral injections increased the proliferation of Mash-1-positive transit-amplifying precursor cells in the SVZ. Conversely, conditional deletion of Cx45 in precursor cells decreased proliferation. Finally, we established that Cx45 positively influences cell cycle reentry via ATP signaling that involves intracellular calcium stores and ERK1/2 signaling.
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