1
|
Semprich CI, Davidson L, Amorim Torres A, Patel H, Briscoe J, Metzis V, Storey KG. ERK1/2 signalling dynamics promote neural differentiation by regulating chromatin accessibility and the polycomb repressive complex. PLoS Biol 2022; 20:e3000221. [PMID: 36455041 PMCID: PMC9746999 DOI: 10.1371/journal.pbio.3000221] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 12/13/2022] [Accepted: 10/11/2022] [Indexed: 12/05/2022] Open
Abstract
Fibroblast growth factor (FGF) is a neural inducer in many vertebrate embryos, but how it regulates chromatin organization to coordinate the activation of neural genes is unclear. Moreover, for differentiation to progress, FGF signalling must decline. Why these signalling dynamics are required has not been determined. Here, we show that dephosphorylation of the FGF effector kinase ERK1/2 rapidly increases chromatin accessibility at neural genes in mouse embryos, and, using ATAC-seq in human embryonic stem cell derived spinal cord precursors, we demonstrate that this occurs genome-wide across neural genes. Importantly, ERK1/2 inhibition induces precocious neural gene transcription, and this involves dissociation of the polycomb repressive complex from key gene loci. This takes place independently of subsequent loss of the repressive histone mark H3K27me3 and transcriptional onset. Transient ERK1/2 inhibition is sufficient for the dissociation of the repressive complex, and this is not reversed on resumption of ERK1/2 signalling. Moreover, genomic footprinting of sites identified by ATAC-seq together with ChIP-seq for polycomb protein Ring1B revealed that ERK1/2 inhibition promotes the occupancy of neural transcription factors (TFs) at non-polycomb as well as polycomb associated sites. Together, these findings indicate that ERK1/2 signalling decline promotes global changes in chromatin accessibility and TF binding at neural genes by directing polycomb and other regulators and appears to serve as a gating mechanism that provides directionality to the process of differentiation.
Collapse
Affiliation(s)
- Claudia I. Semprich
- Division of Cell & Developmental Biology, School of Life Sciences, University of Dundee, Scotland, United Kingdom
| | - Lindsay Davidson
- Division of Cell & Developmental Biology, School of Life Sciences, University of Dundee, Scotland, United Kingdom
| | - Adriana Amorim Torres
- Division of Cell & Developmental Biology, School of Life Sciences, University of Dundee, Scotland, United Kingdom
| | | | | | - Vicki Metzis
- The Francis Crick Institute, London, United Kingdom
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- * E-mail: (VM); (KGS)
| | - Kate G. Storey
- Division of Cell & Developmental Biology, School of Life Sciences, University of Dundee, Scotland, United Kingdom
- * E-mail: (VM); (KGS)
| |
Collapse
|
2
|
Gupta S, Butler SJ. Getting in touch with your senses: Mechanisms specifying sensory interneurons in the dorsal spinal cord. WIREs Mech Dis 2021; 13:e1520. [PMID: 34730293 PMCID: PMC8459260 DOI: 10.1002/wsbm.1520] [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: 11/02/2020] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 11/18/2022]
Abstract
The spinal cord is functionally and anatomically divided into ventrally derived motor circuits and dorsally derived somatosensory circuits. Sensory stimuli originating either at the periphery of the body, or internally, are relayed to the dorsal spinal cord where they are processed by distinct classes of sensory dorsal interneurons (dIs). dIs convey sensory information, such as pain, heat or itch, either to the brain, and/or to the motor circuits to initiate the appropriate response. They also regulate the intensity of sensory information and are the major target for the opioid analgesics. While the developmental mechanisms directing ventral and dorsal cell fates have been hypothesized to be similar, more recent research has suggested that dI fates are specified by novel mechanisms. In this review, we will discuss the molecular events that specify dorsal neuronal patterning in the spinal cord, thereby generating diverse dI identities. We will then discuss how this molecular understanding has led to the development of robust stem cell methods to derive multiple spinal cell types, including the dIs, and the implication of these studies for treating spinal cord injuries and neurodegenerative diseases. This article is categorized under: Neurological Diseases > Stem Cells and Development.
Collapse
Affiliation(s)
- Sandeep Gupta
- Department of NeurobiologyUniversity of California, Los AngelesLos AngelesCaliforniaUSA
| | - Samantha J. Butler
- Department of NeurobiologyUniversity of California, Los AngelesLos AngelesCaliforniaUSA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell ResearchUniversity of California, Los AngelesLos AngelesCaliforniaUSA
- Intellectual and Developmental Disabilities Research CenterUniversity of California, Los AngelesLos AngelesCaliforniaUSA
| |
Collapse
|
3
|
The Role of Fibroblast Growth Factor 19 in Hepatocellular Carcinoma. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1180-1192. [PMID: 34000282 DOI: 10.1016/j.ajpath.2021.04.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 04/09/2021] [Accepted: 04/22/2021] [Indexed: 12/12/2022]
Abstract
Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the third leading cause of cancer-related deaths worldwide. Liver resection or liver transplantation is the most effective therapy for HCC because drugs approved by the US Food and Drug Administration to treat patients with unresectable HCC have an unfavorable overall survival rate. Therefore, the development of biomarkers for early diagnosis and effective therapy strategies are still necessary to improve patient outcomes. Fibroblast growth factor (FGF) 19 was amplified in patients with HCC from various studies, including patients from The Cancer Genome Atlas. FGF19 plays a syngeneic function with other signaling pathways in primary liver cancer development, such as epidermal growth factor receptor, Wnt/β-catenin, the endoplasmic reticulum-related signaling pathway, STAT3/IL-6, RAS, and extracellular signal-regulated protein kinase, among others. The current review presents a comprehensive description of the FGF19 signaling pathway involved in liver cancer development. The use of big data and bioinformatic analysis can provide useful clues for further studies of the FGF19 pathway in HCC, including its application as a biomarker, targeted therapy, and combination therapy strategies.
Collapse
|
4
|
Bejaoui M, Ferdousi F, Zheng YW, Oda T, Isoda H. Regulating cell fate of human amnion epithelial cells using natural compounds: an example of enhanced neural and pigment differentiation by 3,4,5-tri-O-caffeoylquinic acid. Cell Commun Signal 2021; 19:26. [PMID: 33627134 PMCID: PMC7903623 DOI: 10.1186/s12964-020-00697-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Over the past years, Human Amnion Epithelial Cells (hAECs), a placental stem cell, are gaining higher attention from the scientific community as they showed several advantages over other types of stem cells, including availability, easy accessibility, reduced rejection rate, non-tumorigenicity, and minimal legal constraint. Recently, natural compounds are used to stimulate stem cell differentiation and proliferation and to enhance their disease-treating potential. A polyphenolic compound 3,4,5-Tri-O-Caffeoylquinic Acid (TCQA) has been previously reported to induce human neural stem cell differentiation and may affect melanocyte stem cell differentiation as well. In this study, TCQA was tested on 3D cultured hAECs after seven days of treatment, and then, microarray gene expression profiling was conducted of TCQA-treated and untreated control cells on day 0 and day 7. Analyses revealed that TCQA treatment significantly enriched pigment and neural cells sets; besides, genes linked with neurogenesis, oxidation-reduction process, epidermal development, and metabolism were positively regulated. Interestingly, TCQA stimulated cell cycle arrest-related pathways and differentiation signaling. On the other hand, TCQA decreased interleukins and cytokines expression and this due to its anti-inflammatory properties as a polyphenolic compound. Results were validated to highlight the main activities of TCQA on hAECs, including differentiation, cell cycle arrest, and anti-inflammatory. This study highlights the important role of hAECs in regenerative medicine and the use of natural compounds to regulate their fate. Video abstract.
Collapse
Affiliation(s)
- Meriem Bejaoui
- Alliance for Research On the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba, Japan
- AIST-University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), AIST, University of Tsukuba, Tsukuba, Japan
| | - Farhana Ferdousi
- Alliance for Research On the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba, Japan
- AIST-University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), AIST, University of Tsukuba, Tsukuba, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 Japan
| | - Yun-Wen Zheng
- AIST-University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), AIST, University of Tsukuba, Tsukuba, Japan
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Tatsuya Oda
- AIST-University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), AIST, University of Tsukuba, Tsukuba, Japan
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Hiroko Isoda
- Alliance for Research On the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba, Japan
- AIST-University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), AIST, University of Tsukuba, Tsukuba, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 Japan
| |
Collapse
|
5
|
Role of Retinoic Acid Signaling, FGF Signaling and Meis Genes in Control of Limb Development. Biomolecules 2021; 11:biom11010080. [PMID: 33435477 PMCID: PMC7827967 DOI: 10.3390/biom11010080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/31/2020] [Accepted: 01/06/2021] [Indexed: 12/22/2022] Open
Abstract
The function of retinoic acid (RA) during limb development is still debated, as loss and gain of function studies led to opposite conclusions. With regard to limb initiation, genetic studies demonstrated that activation of FGF10 signaling is required for the emergence of limb buds from the trunk, with Tbx5 and RA signaling acting upstream in the forelimb field, whereas Tbx4 and Pitx1 act upstream in the hindlimb field. Early studies in chick embryos suggested that RA as well as Meis1 and Meis2 (Meis1/2) are required for subsequent proximodistal patterning of both forelimbs and hindlimbs, with RA diffusing from the trunk, functioning to activate Meis1/2 specifically in the proximal limb bud mesoderm. However, genetic loss of RA signaling does not result in loss of limb Meis1/2 expression and limb patterning is normal, although Meis1/2 expression is reduced in trunk somitic mesoderm. More recent studies demonstrated that global genetic loss of Meis1/2 results in a somite defect and failure of limb bud initiation. Other new studies reported that conditional genetic loss of Meis1/2 in the limb results in proximodistal patterning defects, and distal FGF8 signaling represses Meis1/2 to constrain its expression to the proximal limb. In this review, we hypothesize that RA and Meis1/2 both function in the trunk to initiate forelimb bud initiation, but that limb Meis1/2 expression is activated proximally by a factor other than RA and repressed distally by FGF8 to generate proximodistal patterning.
Collapse
|
6
|
Auer JMT, Stoddart JJ, Christodoulou I, Lima A, Skouloudaki K, Hall HN, Vukojević V, Papadopoulos DK. Of numbers and movement - understanding transcription factor pathogenesis by advanced microscopy. Dis Model Mech 2020; 13:dmm046516. [PMID: 33433399 PMCID: PMC7790199 DOI: 10.1242/dmm.046516] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Transcription factors (TFs) are life-sustaining and, therefore, the subject of intensive research. By regulating gene expression, TFs control a plethora of developmental and physiological processes, and their abnormal function commonly leads to various developmental defects and diseases in humans. Normal TF function often depends on gene dosage, which can be altered by copy-number variation or loss-of-function mutations. This explains why TF haploinsufficiency (HI) can lead to disease. Since aberrant TF numbers frequently result in pathogenic abnormalities of gene expression, quantitative analyses of TFs are a priority in the field. In vitro single-molecule methodologies have significantly aided the identification of links between TF gene dosage and transcriptional outcomes. Additionally, advances in quantitative microscopy have contributed mechanistic insights into normal and aberrant TF function. However, to understand TF biology, TF-chromatin interactions must be characterised in vivo, in a tissue-specific manner and in the context of both normal and altered TF numbers. Here, we summarise the advanced microscopy methodologies most frequently used to link TF abundance to function and dissect the molecular mechanisms underlying TF HIs. Increased application of advanced single-molecule and super-resolution microscopy modalities will improve our understanding of how TF HIs drive disease.
Collapse
Affiliation(s)
- Julia M T Auer
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | - Jack J Stoddart
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | | | - Ana Lima
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | | | - Hildegard N Hall
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | - Vladana Vukojević
- Center for Molecular Medicine (CMM), Department of Clinical Neuroscience, Karolinska Institutet, 17176 Stockholm, Sweden
| | | |
Collapse
|
7
|
Berenguer M, Meyer KF, Yin J, Duester G. Discovery of genes required for body axis and limb formation by global identification of retinoic acid-regulated epigenetic marks. PLoS Biol 2020; 18:e3000719. [PMID: 32421711 PMCID: PMC7259794 DOI: 10.1371/journal.pbio.3000719] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/29/2020] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
Identification of target genes that mediate required functions downstream of transcription factors is hampered by the large number of genes whose expression changes when the factor is removed from a specific tissue and the numerous binding sites for the factor in the genome. Retinoic acid (RA) regulates transcription via RA receptors bound to RA response elements (RAREs) of which there are thousands in vertebrate genomes. Here, we combined chromatin immunoprecipitation sequencing (ChIP-seq) for epigenetic marks and RNA-seq on trunk tissue from wild-type and Aldh1a2-/- embryos lacking RA synthesis that exhibit body axis and forelimb defects. We identified a relatively small number of genes with altered expression when RA is missing that also have nearby RA-regulated deposition of histone H3 K27 acetylation (H3K27ac) (gene activation mark) or histone H3 K27 trimethylation (H3K27me3) (gene repression mark) associated with conserved RAREs, suggesting these genes function downstream of RA. RA-regulated epigenetic marks were identified near RA target genes already known to be required for body axis and limb formation, thus validating our approach; plus, many other candidate RA target genes were found. Nuclear receptor 2f1 (Nr2f1) and nuclear receptor 2f2 (Nr2f2) in addition to Meis homeobox 1 (Meis1) and Meis homeobox 2 (Meis2) gene family members were identified by our approach, and double knockouts of each family demonstrated previously unknown requirements for body axis and/or limb formation. A similar epigenetic approach can be used to determine the target genes for any transcriptional regulator for which a knockout is available.
Collapse
Affiliation(s)
- Marie Berenguer
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Karolin F. Meyer
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Jun Yin
- Bioinformatics Core Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Gregg Duester
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| |
Collapse
|
8
|
Brown JM, Roberts NA, Graham B, Waithe D, Lagerholm C, Telenius JM, De Ornellas S, Oudelaar AM, Scott C, Szczerbal I, Babbs C, Kassouf MT, Hughes JR, Higgs DR, Buckle VJ. A tissue-specific self-interacting chromatin domain forms independently of enhancer-promoter interactions. Nat Commun 2018; 9:3849. [PMID: 30242161 PMCID: PMC6155075 DOI: 10.1038/s41467-018-06248-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 08/24/2018] [Indexed: 11/08/2022] Open
Abstract
Self-interacting chromatin domains encompass genes and their cis-regulatory elements; however, the three-dimensional form a domain takes, whether this relies on enhancer-promoter interactions, and the processes necessary to mediate the formation and maintenance of such domains, remain unclear. To examine these questions, here we use a combination of high-resolution chromosome conformation capture, a non-denaturing form of fluorescence in situ hybridisation and super-resolution imaging to study a 70 kb domain encompassing the mouse α-globin regulatory locus. We show that this region forms an erythroid-specific, decompacted, self-interacting domain, delimited by frequently apposed CTCF/cohesin binding sites early in terminal erythroid differentiation, and does not require transcriptional elongation for maintenance of the domain structure. Formation of this domain does not rely on interactions between the α-globin genes and their major enhancers, suggesting a transcription-independent mechanism for establishment of the domain. However, absence of the major enhancers does alter internal domain interactions. Formation of a loop domain therefore appears to be a mechanistic process that occurs irrespective of the specific interactions within.
Collapse
Affiliation(s)
- Jill M Brown
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Nigel A Roberts
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Bryony Graham
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Dominic Waithe
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | - Christoffer Lagerholm
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | - Jelena M Telenius
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Sara De Ornellas
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - A Marieke Oudelaar
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Caroline Scott
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Izabela Szczerbal
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637 Poznan, Poland
| | - Christian Babbs
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Mira T Kassouf
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Jim R Hughes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Douglas R Higgs
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Veronica J Buckle
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK.
| |
Collapse
|
9
|
Mastromina I, Verrier L, Silva JC, Storey KG, Dale JK. Myc activity is required for maintenance of the neuromesodermal progenitor signalling network and for segmentation clock gene oscillations in mouse. Development 2018; 145:dev161091. [PMID: 30061166 PMCID: PMC6078331 DOI: 10.1242/dev.161091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 06/08/2018] [Indexed: 12/19/2022]
Abstract
The Myc transcriptional regulators are implicated in a range of cellular functions, including proliferation, cell cycle progression, metabolism and pluripotency maintenance. Here, we investigated the expression, regulation and function of the Myc family during mouse embryonic axis elongation and segmentation. Expression of both cMyc (Myc - Mouse Genome Informatics) and MycN in the domains in which neuromesodermal progenitors (NMPs) and underlying caudal pre-somitic mesoderm (cPSM) cells reside is coincident with WNT and FGF signals, factors known to maintain progenitors in an undifferentiated state. Pharmacological inhibition of Myc activity downregulates expression of WNT/FGF components. In turn, we find that cMyc expression is WNT, FGF and Notch protein regulated, placing it centrally in the signalling circuit that operates in the tail end that both sustains progenitors and drives maturation of the PSM into somites. Interfering with Myc function in the PSM, where it displays oscillatory expression, delays the timing of segmentation clock oscillations and thus of somite formation. In summary, we identify Myc as a component that links NMP maintenance and PSM maturation during the body axis elongation stages of mouse embryogenesis.
Collapse
Affiliation(s)
- Ioanna Mastromina
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Laure Verrier
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Joana Clara Silva
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Kate G Storey
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - J Kim Dale
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| |
Collapse
|
10
|
Cardozo MJ, Mysiak KS, Becker T, Becker CG. Reduce, reuse, recycle – Developmental signals in spinal cord regeneration. Dev Biol 2017; 432:53-62. [DOI: 10.1016/j.ydbio.2017.05.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/03/2017] [Accepted: 05/11/2017] [Indexed: 02/06/2023]
|
11
|
Ryabichko SS, Ibragimov AN, Lebedeva LA, Kozlov EN, Shidlovskii YV. Super-Resolution Microscopy in Studying the Structure and Function of the Cell Nucleus. Acta Naturae 2017; 9:42-51. [PMID: 29340216 PMCID: PMC5762827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Indexed: 11/21/2022] Open
Abstract
In recent decades, novel microscopic methods commonly referred to as super- resolution microscopy have been developed. These methods enable the visualization of a cell with a resolution of up to 10 nm. The application of these methods is of great interest in studying the structure and function of the cell nucleus. The review describes the main achievements in this field.
Collapse
Affiliation(s)
- S. S. Ryabichko
- Institute of Gene Biology RAS, Vavilova Str. 34/5, Moscow, 119334, Russia
| | - A. N. Ibragimov
- Institute of Gene Biology RAS, Vavilova Str. 34/5, Moscow, 119334, Russia
| | - L. A. Lebedeva
- Institute of Gene Biology RAS, Vavilova Str. 34/5, Moscow, 119334, Russia
| | - E. N. Kozlov
- Institute of Gene Biology RAS, Vavilova Str. 34/5, Moscow, 119334, Russia
| | - Y. V. Shidlovskii
- Institute of Gene Biology RAS, Vavilova Str. 34/5, Moscow, 119334, Russia
- I.M. Sechenov First Moscow State Medical University, Trubetskaya Str. 8, bldg. 2, Moscow, 119048 , Russia
| |
Collapse
|
12
|
Abstract
Specialized areas in the vertebrate retina are critical for high-acuity vision, yet the molecular mechanisms driving the development of high-acuity areas (HAAs) remain largely unknown. In Developmental Cell, da Silva and Cepko (2017) show that restricted degradation of retinoic acid and elevated FGF8 signaling give rise to the chick HAA.
Collapse
Affiliation(s)
- Adele Tufford
- Cellular Neurobiology Research Unit, Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada; Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada.
| |
Collapse
|
13
|
Abstract
During vertebrate embryonic development, the spinal cord is formed by the neural derivatives of a neuromesodermal population that is specified at early stages of development and which develops in concert with the caudal regression of the primitive streak. Several processes related to spinal cord specification and maturation are coupled to this caudal extension including neurogenesis, ventral patterning and neural crest specification and all of them seem to be crucially regulated by Fibroblast Growth Factor (FGF) signaling, which is prominently active in the neuromesodermal region and transiently in its derivatives. Here we review the role of FGF signaling in those processes, trying to separate its different functions and highlighting the interactions with other signaling pathways. Finally, these early functions of FGF signaling in spinal cord development may underlay partly its ability to promote regeneration in the lesioned spinal cord as well as its action promoting specific fates in neural stem cell cultures that may be used for therapeutical purposes.
Collapse
Affiliation(s)
- Ruth Diez Del Corral
- Department of Cellular, Molecular and Developmental Neurobiology, Cajal Institute, Consejo Superior de Investigaciones CientíficasMadrid, Spain.,Champalimaud Research, Champalimaud Centre for the UnknownLisbon, Portugal
| | - Aixa V Morales
- Department of Cellular, Molecular and Developmental Neurobiology, Cajal Institute, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| |
Collapse
|
14
|
Ioannou D, Millan NM, Jordan E, Tempest HG. A new model of sperm nuclear architecture following assessment of the organization of centromeres and telomeres in three-dimensions. Sci Rep 2017; 7:41585. [PMID: 28139771 PMCID: PMC5282497 DOI: 10.1038/srep41585] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 12/21/2016] [Indexed: 01/01/2023] Open
Abstract
The organization of chromosomes in sperm nuclei has been proposed to possess a unique “hairpin-loop” arrangement, which is hypothesized to aid in the ordered exodus of the paternal genome following fertilization. This study simultaneously assessed the 3D and 2D radial and longitudinal organization of telomeres, centromeres, and investigated whether chromosomes formed the same centromere clusters in sperm cells. Reproducible radial and longitudinal non-random organization was observed for all investigated loci using both 3D and 2D approaches in multiple subjects. We report novel findings, with telomeres and centromeres being localized throughout the nucleus but demonstrating roughly a 1:1 distribution in the nuclear periphery and the intermediate regions with <15% occupying the nuclear interior. Telomeres and centromeres were observed to aggregate in sperm nuclei, forming an average of 20 and 7 clusters, respectively. Reproducible
longitudinal organization demonstrated preferential localization of telomeres and centromeres in the mid region of the sperm cell. Preliminary evidence is also provided to support the hypothesis that specific chromosomes preferentially form the same centromere clusters. The more segmental distribution of telomeres and centromeres as described in this study could more readily accommodate and facilitate the sequential exodus of paternal chromosomes following fertilization.
Collapse
Affiliation(s)
- Dimitrios Ioannou
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Nicole M Millan
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Elizabeth Jordan
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Helen G Tempest
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| |
Collapse
|
15
|
Wang J, Fu X, Zhang D, Yu L, Li N, Lu Z, Gao Y, Wang M, Liu X, Zhou C, Han W, Yan B, Wang J. ChAT-positive neurons participate in subventricular zone neurogenesis after middle cerebral artery occlusion in mice. Behav Brain Res 2017; 316:145-151. [PMID: 27609645 PMCID: PMC5048585 DOI: 10.1016/j.bbr.2016.09.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 08/30/2016] [Accepted: 09/03/2016] [Indexed: 11/28/2022]
Abstract
The mechanisms of post-stroke neurogenesis in the subventricular zone (SVZ) are unclear. However, neural stem cell-intrinsic and neurogenic niche mechanisms, as well as neurotransmitters, have been shown to play important roles in SVZ neurogenesis. Recently, a previously unknown population of choline acetyltransferase (ChAT)+ neurons residing in rodent SVZ were identified to have direct control over neural stem cell proliferation by indirectly activating fibroblast growth factor receptor (FGFR). This finding revealed possible neuronal control over SVZ neurogenesis. In this study, we assessed whether these ChAT+ neurons also participate in stroke-induced neurogenesis. We used a permanent middle cerebral artery occlusion (MCAO) model produced by transcranial electrocoagulation in mice, atropine (muscarinic cholinergic receptor [mAchR] antagonist), and donepezil (acetylcholinesterase inhibitor) to investigate the role of ChAT+ neurons in stroke-induced neurogenesis. We found that mAchRs, phosphorylated protein kinase C (p-PKC), and p-38 levels in the SVZ were upregulated in mice on day 7 after MCAO. MCAO also significantly increased the number of BrdU/doublecortin-positive cells and protein levels of phosphorylated-neural cell adhesion molecule and mammalian achaete scute homolog-1. FGFR was activated in the SVZ, and doublecortin-positive cells increased in the peri-infarction region. These post-stroke neurogenic effects were enhanced by donepezil and partially decreased by atropine. Neither atropine nor donepezil affected peri-infarct microglial activation or serum concentrations of TNF-α, IFN-γ, or TGF-β on day 7 after MCAO. We conclude that ChAT+ neurons in the SVZ may participate in stroke-induced neurogenesis, suggesting a new mechanism for neurogenesis after stroke.
Collapse
Affiliation(s)
- Jianping Wang
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Xiaojie Fu
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Di Zhang
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Lie Yu
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Nan Li
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Zhengfang Lu
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Yufeng Gao
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Menghan Wang
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Xi Liu
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Chenguang Zhou
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Wei Han
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Bo Yan
- Department of Radiology, The Fourth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Jian Wang
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
- Department of Anesthesiology/Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| |
Collapse
|
16
|
New Insights Into the Roles of Retinoic Acid Signaling in Nervous System Development and the Establishment of Neurotransmitter Systems. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 330:1-84. [PMID: 28215529 DOI: 10.1016/bs.ircmb.2016.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Secreted chiefly from the underlying mesoderm, the morphogen retinoic acid (RA) is well known to contribute to the specification, patterning, and differentiation of neural progenitors in the developing vertebrate nervous system. Furthermore, RA influences the subtype identity and neurotransmitter phenotype of subsets of maturing neurons, although relatively little is known about how these functions are mediated. This review provides a comprehensive overview of the roles played by RA signaling during the formation of the central and peripheral nervous systems of vertebrates and highlights its effects on the differentiation of several neurotransmitter systems. In addition, the evolutionary history of the RA signaling system is discussed, revealing both conserved properties and alternate modes of RA action. It is proposed that comparative approaches should be employed systematically to expand our knowledge of the context-dependent cellular mechanisms controlled by the multifunctional signaling molecule RA.
Collapse
|
17
|
From single molecules to life: microscopy at the nanoscale. Anal Bioanal Chem 2016; 408:6885-911. [PMID: 27613013 PMCID: PMC5566169 DOI: 10.1007/s00216-016-9781-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/30/2016] [Accepted: 07/07/2016] [Indexed: 01/08/2023]
Abstract
Super-resolution microscopy is the term commonly given to fluorescence microscopy techniques with resolutions that are not limited by the diffraction of light. Since their conception a little over a decade ago, these techniques have quickly become the method of choice for many biologists studying structures and processes of single cells at the nanoscale. In this review, we present the three main approaches used to tackle the diffraction barrier of ∼200 nm: stimulated-emission depletion (STED) microscopy, structured illumination microscopy (SIM), and single-molecule localization microscopy (SMLM). We first present a theoretical overview of the techniques and underlying physics, followed by a practical guide to all of the facets involved in designing a super-resolution experiment, including an approachable explanation of the photochemistry involved, labeling methods available, and sample preparation procedures. Finally, we highlight some of the most exciting recent applications of and developments in these techniques, and discuss the outlook for this field. Super-resolution microscopy techniques. Working principles of the common approaches stimulated-emission depletion (STED) microscopy, structured illumination microscopy (SIM), and single-molecule localization microscopy (SMLM). ![]()
Collapse
|
18
|
Kumar S, Cunningham TJ, Duester G. Nuclear receptor corepressors Ncor1 and Ncor2 (Smrt) are required for retinoic acid-dependent repression of Fgf8 during somitogenesis. Dev Biol 2016; 418:204-215. [PMID: 27506116 DOI: 10.1016/j.ydbio.2016.08.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/30/2016] [Accepted: 08/05/2016] [Indexed: 10/21/2022]
Abstract
Retinoic acid (RA) repression of Fgf8 is required for many different aspects of organogenesis, however relatively little is known about how endogenous RA controls gene repression as opposed to gene activation. Here, we show that nuclear receptor corepressors NCOR1 and NCOR2 (SMRT) redundantly mediate the ability of RA to repress Fgf8. Ncor1;Ncor2 double mutants generated by CRISPR/Cas9 gene editing exhibited a small somite and distended heart phenotype similar to that of RA-deficient Raldh2-/- embryos, associated with increased Fgf8 expression and FGF signaling in caudal progenitors and heart progenitors. Embryo chromatin immunoprecipitation studies revealed that NCOR1/2 but not coactivators are recruited to the Fgf8 RA response element (RARE) in an RA-dependent manner, whereas coactivators but not NCOR1/2 are recruited RA-dependently to a RARE near Rarb that is activated by RA. CRISPR/Cas9-mediated genomic deletion of the Fgf8 RARE in mouse embryos often resulted in a small somite defect with Fgf8 derepression caudally, but no defect was observed in heart development or heart Fgf8 expression. This suggests the existence of another DNA element whose function overlaps with the Fgf8 RARE to mediate Fgf8 repression by RA and NCOR1/2. Our studies support a model in which NCOR1/2 mediates direct RA-dependent repression of Fgf8 in caudal progenitors in order to control somitogenesis.
Collapse
Affiliation(s)
- Sandeep Kumar
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Thomas J Cunningham
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Gregg Duester
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
| |
Collapse
|
19
|
Williamson I, Lettice LA, Hill RE, Bickmore WA. Shh and ZRS enhancer colocalisation is specific to the zone of polarising activity. Development 2016; 143:2994-3001. [PMID: 27402708 PMCID: PMC5004883 DOI: 10.1242/dev.139188] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/06/2016] [Indexed: 12/28/2022]
Abstract
Limb-specific Shh expression is regulated by the (∼1 Mb distant) ZRS enhancer. In the mouse, limb bud-restricted spatiotemporal Shh expression occurs from ∼E10 to E11.5 at the distal posterior margin and is essential for correct autopod formation. Here, we have analysed the higher-order chromatin conformation of Shh in expressing and non-expressing tissues, both by fluorescence in situ hybridisation (FISH) and by chromosome conformation capture (5C). Conventional and super-resolution light microscopy identified significantly elevated frequencies of Shh/ZRS colocalisation only in the Shh-expressing regions of the limb bud, in a conformation consistent with enhancer-promoter loop formation. However, in all tissues and at all developmental stages analysed, Shh-ZRS spatial distances were still consistently shorter than those to a neural enhancer located between Shh and ZRS in the genome. 5C identified a topologically associating domain (TAD) over the Shh/ZRS genomic region and enriched interactions between Shh and ZRS throughout E11.5 embryos. Shh/ZRS colocalisation, therefore, correlates with the spatiotemporal domain of limb bud-specific Shh expression, but close Shh and ZRS proximity in the nucleus occurs regardless of whether the gene or enhancer is active. We suggest that this constrained chromatin configuration optimises the opportunity for the active enhancer to locate and instigate the expression of Shh. Summary: Super-resolution microscopy reveals that, during mouse limb development, enhancer-driven gene expression results in the juxtaposition of Shh and its limb bud-specific enhancer only within cells of the distal posterior limb bud.
Collapse
Affiliation(s)
- Iain Williamson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh EH4 2XU, UK
| | - Laura A Lettice
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh EH4 2XU, UK
| | - Robert E Hill
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh EH4 2XU, UK
| | - Wendy A Bickmore
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh EH4 2XU, UK
| |
Collapse
|
20
|
Gao J, Yang X, Djekidel MN, Wang Y, Xi P, Zhang MQ. Developing bioimaging and quantitative methods to study 3D genome. QUANTITATIVE BIOLOGY 2016. [DOI: 10.1007/s40484-016-0065-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
21
|
Morales AV, Espeso-Gil S, Ocaña I, Nieto-Lopez F, Calleja E, Bovolenta P, Lewandoski M, Diez Del Corral R. FGF signaling enhances a sonic hedgehog negative feedback loop at the initiation of spinal cord ventral patterning. Dev Neurobiol 2015; 76:956-71. [PMID: 26600420 DOI: 10.1002/dneu.22368] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 11/18/2015] [Indexed: 12/23/2022]
Abstract
A prevalent developmental mechanism for the assignment of cell identities is the production of spatiotemporal concentration gradients of extracellular signaling molecules that are interpreted by the responding cells. One of such signaling systems is the Shh gradient that controls neuronal subtype identity in the ventral spinal cord. Using loss and gain of function approaches in chick and mouse embryos, we show here that the fibroblast growth factor (FGF) signaling pathway is required to restrict the domains of ventral gene expression as neuroepithelial cells become exposed to Shh during caudal extension of the embryo. FGF signaling activates the expression of the Shh receptor and negative pathway regulator Patched 2 (Ptch2) and therefore can enhance a negative feedback loop that restrains the activity of the pathway. Thus, we identify one of the mechanisms by which FGF signaling acts as a modulator of the onset of Shh signaling activity in the context of coordination of ventral patterning and caudal axis extension. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 956-971, 2016.
Collapse
Affiliation(s)
- Aixa V Morales
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain
| | - Sergio Espeso-Gil
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain
| | - Inmaculada Ocaña
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain.,CIBER de Enfermedades Raras, Spain
| | - Francisco Nieto-Lopez
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain.,CIBER de Enfermedades Raras, Spain.,Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-UAM, Cantoblanco, 28049, Spain
| | - Elena Calleja
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain
| | - Paola Bovolenta
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain.,CIBER de Enfermedades Raras, Spain.,Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-UAM, Cantoblanco, 28049, Spain
| | - Mark Lewandoski
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, 21702, USA
| | - Ruth Diez Del Corral
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, 28002, Spain
| |
Collapse
|
22
|
Cunningham TJ, Brade T, Sandell LL, Lewandoski M, Trainor PA, Colas A, Mercola M, Duester G. Retinoic Acid Activity in Undifferentiated Neural Progenitors Is Sufficient to Fulfill Its Role in Restricting Fgf8 Expression for Somitogenesis. PLoS One 2015; 10:e0137894. [PMID: 26368825 PMCID: PMC4569375 DOI: 10.1371/journal.pone.0137894] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/24/2015] [Indexed: 12/20/2022] Open
Abstract
Bipotent axial stem cells residing in the caudal epiblast during late gastrulation generate neuroectodermal and presomitic mesodermal progeny that coordinate somitogenesis with neural tube formation, but the mechanism that controls these two fates is not fully understood. Retinoic acid (RA) restricts the anterior extent of caudal fibroblast growth factor 8 (Fgf8) expression in both mesoderm and neural plate to control somitogenesis and neurogenesis, however it remains unclear where RA acts to control the spatial expression of caudal Fgf8. Here, we found that mouse Raldh2-/- embryos, lacking RA synthesis and displaying a consistent small somite defect, exhibited abnormal expression of key markers of axial stem cell progeny, with decreased Sox2+ and Sox1+ neuroectodermal progeny and increased Tbx6+ presomitic mesodermal progeny. The Raldh2-/- small somite defect was rescued by treatment with an FGF receptor antagonist. Rdh10 mutants, with a less severe RA synthesis defect, were found to exhibit a small somite defect and anterior expansion of caudal Fgf8 expression only for somites 1-6, with normal somite size and Fgf8 expression thereafter. Rdh10 mutants were found to lack RA activity during the early phase when somites are small, but at the 6-somite stage RA activity was detected in neural plate although not in presomitic mesoderm. Expression of a dominant-negative RA receptor in mesoderm eliminated RA activity in presomitic mesoderm but did not affect somitogenesis. Thus, RA activity in the neural plate is sufficient to prevent anterior expansion of caudal Fgf8 expression associated with a small somite defect. Our studies provide evidence that RA restriction of Fgf8 expression in undifferentiated neural progenitors stimulates neurogenesis while also restricting the anterior extent of the mesodermal Fgf8 mRNA gradient that controls somite size, providing new insight into the mechanism that coordinates somitogenesis with neurogenesis.
Collapse
Affiliation(s)
- Thomas J. Cunningham
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Thomas Brade
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Lisa L. Sandell
- Department of Molecular, Cellular, and Craniofacial Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Mark Lewandoski
- Laboratory of Cancer and Developmental Biology, National Cancer Institute, National Institutes of Health, Frederick, Maryland, United States of America
| | - Paul A. Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Alexandre Colas
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- Department of Bioengineering, University of California at San Diego, La Jolla, California, United States of America
| | - Mark Mercola
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- Department of Bioengineering, University of California at San Diego, La Jolla, California, United States of America
| | - Gregg Duester
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
23
|
Fraser J, Williamson I, Bickmore WA, Dostie J. An Overview of Genome Organization and How We Got There: from FISH to Hi-C. Microbiol Mol Biol Rev 2015; 79:347-72. [PMID: 26223848 PMCID: PMC4517094 DOI: 10.1128/mmbr.00006-15] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In humans, nearly two meters of genomic material must be folded to fit inside each micrometer-scale cell nucleus while remaining accessible for gene transcription, DNA replication, and DNA repair. This fact highlights the need for mechanisms governing genome organization during any activity and to maintain the physical organization of chromosomes at all times. Insight into the functions and three-dimensional structures of genomes comes mostly from the application of visual techniques such as fluorescence in situ hybridization (FISH) and molecular approaches including chromosome conformation capture (3C) technologies. Recent developments in both types of approaches now offer the possibility of exploring the folded state of an entire genome and maybe even the identification of how complex molecular machines govern its shape. In this review, we present key methodologies used to study genome organization and discuss what they reveal about chromosome conformation as it relates to transcription regulation across genomic scales in mammals.
Collapse
Affiliation(s)
- James Fraser
- Department of Biochemistry, and Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
| | - Iain Williamson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Wendy A Bickmore
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Josée Dostie
- Department of Biochemistry, and Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
| |
Collapse
|
24
|
Ypsilanti AR, Rubenstein JLR. Transcriptional and epigenetic mechanisms of early cortical development: An examination of how Pax6 coordinates cortical development. J Comp Neurol 2015; 524:609-29. [PMID: 26304102 DOI: 10.1002/cne.23866] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 07/14/2015] [Accepted: 07/17/2015] [Indexed: 12/26/2022]
Abstract
The development of the cortex is an elaborate process that integrates a plethora of finely tuned molecular processes ranging from carefully regulated gradients of transcription factors, dynamic changes in the chromatin landscape, or formation of protein complexes to elicit and regulate transcription. Combined with cellular processes such as cell type specification, proliferation, differentiation, and migration, all of these developmental processes result in the establishment of an adult mammalian cortex with its typical lamination and regional patterning. By examining in-depth the role of one transcription factor, Pax6, on the regulation of cortical development, its integration in the regulation of chromatin state, and its regulation by cis-regulatory elements, we aim to demonstrate the importance of integrating each level of regulation in our understanding of cortical development.
Collapse
Affiliation(s)
- Athéna R Ypsilanti
- Department of Psychiatry, Neuroscience Program, and the Nina Ireland Laboratory of Developmental Neurobiology, University of California, San Francisco, San Francisco, California
| | - John L R Rubenstein
- Department of Psychiatry, Neuroscience Program, and the Nina Ireland Laboratory of Developmental Neurobiology, University of California, San Francisco, San Francisco, California
| |
Collapse
|
25
|
Rafique S, Thomas JS, Sproul D, Bickmore WA. Estrogen-induced chromatin decondensation and nuclear re-organization linked to regional epigenetic regulation in breast cancer. Genome Biol 2015; 16:145. [PMID: 26235388 PMCID: PMC4536608 DOI: 10.1186/s13059-015-0719-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/06/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Epigenetic changes are being increasingly recognized as a prominent feature of cancer. This occurs not only at individual genes, but also over larger chromosomal domains. To investigate this, we set out to identify large chromosomal domains of epigenetic dysregulation in breast cancers. RESULTS We identify large regions of coordinate down-regulation of gene expression, and other regions of coordinate activation, in breast cancers and show that these regions are linked to tumor subtype. In particular we show that a group of coordinately regulated regions are expressed in luminal, estrogen-receptor positive breast tumors and cell lines. For one of these regions of coordinate gene activation, we show that regional epigenetic regulation is accompanied by visible unfolding of large-scale chromatin structure and a repositioning of the region within the nucleus. In MCF7 cells, we show that this depends on the presence of estrogen. CONCLUSIONS Our data suggest that the liganded estrogen receptor is linked to long-range changes in higher-order chromatin organization and epigenetic dysregulation in cancer. This may suggest that as well as drugs targeting histone modifications, it will be valuable to investigate the inhibition of protein complexes involved in chromatin folding in cancer cells.
Collapse
Affiliation(s)
- Sehrish Rafique
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU, UK. .,Edinburgh Breakthrough Research Unit and Edinburgh Cancer Centre, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh, Scotland, EH4 2XU, UK.
| | - Jeremy S Thomas
- Edinburgh Breakthrough Research Unit and Edinburgh Cancer Centre, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh, Scotland, EH4 2XU, UK.
| | - Duncan Sproul
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU, UK. .,Edinburgh Breakthrough Research Unit and Edinburgh Cancer Centre, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh, Scotland, EH4 2XU, UK.
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU, UK.
| |
Collapse
|
26
|
Beliveau BJ, Boettiger AN, Avendaño MS, Jungmann R, McCole RB, Joyce EF, Kim-Kiselak C, Bantignies F, Fonseka CY, Erceg J, Hannan MA, Hoang HG, Colognori D, Lee JT, Shih WM, Yin P, Zhuang X, Wu CT. Single-molecule super-resolution imaging of chromosomes and in situ haplotype visualization using Oligopaint FISH probes. Nat Commun 2015; 6:7147. [PMID: 25962338 PMCID: PMC4430122 DOI: 10.1038/ncomms8147] [Citation(s) in RCA: 238] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 04/09/2015] [Indexed: 01/06/2023] Open
Abstract
Fluorescence in situ hybridization (FISH) is a powerful single-cell technique for studying nuclear structure and organization. Here we report two advances in FISH-based imaging. We first describe the in situ visualization of single-copy regions of the genome using two single-molecule super-resolution methodologies. We then introduce a robust and reliable system that harnesses single-nucleotide polymorphisms (SNPs) to visually distinguish the maternal and paternal homologous chromosomes in mammalian and insect systems. Both of these new technologies are enabled by renewable, bioinformatically designed, oligonucleotide-based Oligopaint probes, which we augment with a strategy that uses secondary oligonucleotides (oligos) to produce and enhance fluorescent signals. These advances should substantially expand the capability to query parent-of-origin-specific chromosome positioning and gene expression on a cell-by-cell basis.
Collapse
Affiliation(s)
- Brian J. Beliveau
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Alistair N. Boettiger
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Howard Hughes Medical Institute, Cambridge, Massachusetts 02138, USA
| | - Maier S. Avendaño
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Ralf Jungmann
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Ruth B. McCole
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Eric F. Joyce
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Caroline Kim-Kiselak
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Frédéric Bantignies
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
- Institut de Génétique Humaine, CNRS UPR 1142, 141 rue de la Cardonille, 34396 Montpellier, France
| | - Chamith Y. Fonseka
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jelena Erceg
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mohammed A. Hannan
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Hien G. Hoang
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - David Colognori
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
- Howard Hughes Medical Institute, Boston, Massachusetts 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Jeannie T. Lee
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
- Howard Hughes Medical Institute, Boston, Massachusetts 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - William M. Shih
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
| | - Peng Yin
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, USA
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Xiaowei Zhuang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Howard Hughes Medical Institute, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Chao-ting Wu
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
27
|
Gouti M, Metzis V, Briscoe J. The route to spinal cord cell types: a tale of signals and switches. Trends Genet 2015; 31:282-9. [PMID: 25823696 DOI: 10.1016/j.tig.2015.03.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 02/28/2015] [Accepted: 03/02/2015] [Indexed: 01/20/2023]
Abstract
Understanding the mechanisms that control induction and elaboration of the vertebrate central nervous system (CNS) requires an analysis of the extrinsic signals and downstream transcriptional networks that assign cell fates in the correct space and time. We focus on the generation and patterning of the spinal cord. We summarize evidence that the origin of the spinal cord is distinct from the anterior regions of the CNS. We discuss how this affects the gene regulatory networks and cell state transitions that specify spinal cord cell subtypes, and we highlight how the timing of extracellular signals and dynamic control of transcriptional networks contribute to the correct spatiotemporal generation of different neural cell types.
Collapse
Affiliation(s)
- Mina Gouti
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Vicki Metzis
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - James Briscoe
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, UK.
| |
Collapse
|
28
|
Cunningham TJ, Duester G. Mechanisms of retinoic acid signalling and its roles in organ and limb development. Nat Rev Mol Cell Biol 2015; 16:110-23. [PMID: 25560970 PMCID: PMC4636111 DOI: 10.1038/nrm3932] [Citation(s) in RCA: 379] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Retinoic acid (RA) signalling has a central role during vertebrate development. RA synthesized in specific locations regulates transcription by interacting with nuclear RA receptors (RARs) bound to RA response elements (RAREs) near target genes. RA was first implicated in signalling on the basis of its teratogenic effects on limb development. Genetic studies later revealed that endogenous RA promotes forelimb initiation by repressing fibroblast growth factor 8 (Fgf8). Insights into RA function in the limb serve as a paradigm for understanding how RA regulates other developmental processes. In vivo studies have identified RAREs that control repression of Fgf8 during body axis extension or activation of homeobox (Hox) genes and other key regulators during neuronal differentiation and organogenesis.
Collapse
Affiliation(s)
- Thomas J Cunningham
- Development, Aging, and Regeneration Program, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Gregg Duester
- Development, Aging, and Regeneration Program, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Road, La Jolla, California 92037, USA
| |
Collapse
|
29
|
Williamson I, Berlivet S, Eskeland R, Boyle S, Illingworth RS, Paquette D, Dostie J, Bickmore WA. Spatial genome organization: contrasting views from chromosome conformation capture and fluorescence in situ hybridization. Genes Dev 2014; 28:2778-91. [PMID: 25512564 PMCID: PMC4265680 DOI: 10.1101/gad.251694.114] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/30/2014] [Indexed: 01/28/2023]
Abstract
Although important for gene regulation, most studies of genome organization use either fluorescence in situ hybridization (FISH) or chromosome conformation capture (3C) methods. FISH directly visualizes the spatial relationship of sequences but is usually applied to a few loci at a time. The frequency at which sequences are ligated together by formaldehyde cross-linking can be measured genome-wide by 3C methods, with higher frequencies thought to reflect shorter distances. FISH and 3C should therefore give the same views of genome organization, but this has not been tested extensively. We investigated the murine HoxD locus with 3C carbon copy (5C) and FISH in different developmental and activity states and in the presence or absence of epigenetic regulators. We identified situations in which the two data sets are concordant but found other conditions under which chromatin topographies extrapolated from 5C or FISH data are not compatible. We suggest that products captured by 3C do not always reflect spatial proximity, with ligation occurring between sequences located hundreds of nanometers apart, influenced by nuclear environment and chromatin composition. We conclude that results obtained at high resolution with either 3C methods or FISH alone must be interpreted with caution and that views about genome organization should be validated by independent methods.
Collapse
Affiliation(s)
- Iain Williamson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Soizik Berlivet
- Department of Biochemistry, Goodman Cancer Research Center, McGill University, Montréal, Québec H3G1Y6, Canada
| | - Ragnhild Eskeland
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Shelagh Boyle
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Robert S Illingworth
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | | | | | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom;
| |
Collapse
|
30
|
Kumar S, Duester G. Retinoic acid controls body axis extension by directly repressing Fgf8 transcription. Development 2014; 141:2972-7. [PMID: 25053430 DOI: 10.1242/dev.112367] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinoic acid (RA) generated in the mesoderm of vertebrate embryos controls body axis extension by downregulating Fgf8 expression in cells exiting the caudal progenitor zone. RA activates transcription by binding to nuclear RA receptors (RARs) at RA response elements (RAREs), but it is unknown whether RA can directly repress transcription. Here, we analyzed a conserved RARE upstream of Fgf8 that binds RAR isoforms in mouse embryos. Transgenic embryos carrying Fgf8 fused to lacZ exhibited expression similar to caudal Fgf8, but deletion of the RARE resulted in ectopic trunk expression extending into somites and neuroectoderm. Epigenetic analysis using chromatin immunoprecipitation of trunk tissues from E8.25 wild-type and Raldh2(-/-) embryos lacking RA synthesis revealed RA-dependent recruitment of the repressive histone marker H3K27me3 and polycomb repressive complex 2 (PRC2) near the Fgf8 RARE. The co-regulator RERE, the loss of which results in ectopic Fgf8 expression and somite defects, was recruited near the RARb RARE by RA, but was released from the Fgf8 RARE by RA. Our findings demonstrate that RA directly represses Fgf8 through a RARE-mediated mechanism that promotes repressive chromatin, thus providing valuable insight into the mechanism of RA-FGF antagonism during progenitor cell differentiation.
Collapse
Affiliation(s)
- Sandeep Kumar
- Development, Aging, and Regeneration Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Gregg Duester
- Development, Aging, and Regeneration Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| |
Collapse
|
31
|
Leotta CG, Federico C, Brundo MV, Tosi S, Saccone S. HLXB9 gene expression, and nuclear location during in vitro neuronal differentiation in the SK-N-BE neuroblastoma cell line. PLoS One 2014; 9:e105481. [PMID: 25136833 PMCID: PMC4138170 DOI: 10.1371/journal.pone.0105481] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/23/2014] [Indexed: 01/26/2023] Open
Abstract
Different parts of the genome occupy specific compartments of the cell nucleus based on the gene content and the transcriptional activity. An example of this is the altered nuclear positioning of the HLXB9 gene in leukaemia cells observed in association with its over-expression. This phenomenon was attributed to the presence of a chromosomal translocation with breakpoint proximal to the HLXB9 gene. Before becoming an interesting gene in cancer biology, HLXB9 was studied as a developmental gene. This homeobox gene is also known as MNX1 (motor neuron and pancreas homeobox 1) and it is relevant for both motor neuronal and pancreatic beta cells development. A spectrum of mutations in this gene are causative of sacral agenesis and more broadly, of what is known as the Currarino Syndrome, a constitutional autosomal dominant disorder. Experimental work on animal models has shown that HLXB9 has an essential role in motor neuronal differentiation. Here we present data to show that, upon treatment with retinoic acid, the HLXB9 gene becomes over-expressed during the early stages of neuronal differentiation and that this corresponds to a reposition of the gene in the nucleus. More precisely, we used the SK-N-BE human neuroblastoma cell line as an in vitro model and we demonstrated a transient transcription of HLXB9 at the 4th and 5th days of differentiation that corresponded to the presence, predominantly in the cell nuclei, of the encoded protein HB9. The nuclear positioning of the HLXB9 gene was monitored at different stages: a peripheral location was noted in the proliferating cells whereas a more internal position was noted during differentiation, that is while HLXB9 was transcriptionally active. Our findings suggest that HLXB9 can be considered a marker of early neuronal differentiation, possibly involving chromatin remodeling pathways.
Collapse
Affiliation(s)
- Claudia Giovanna Leotta
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Biologia Animale, University of Catania, Catania, Italy
| | - Concetta Federico
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Biologia Animale, University of Catania, Catania, Italy
| | - Maria Violetta Brundo
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Biologia Animale, University of Catania, Catania, Italy
| | - Sabrina Tosi
- Leukaemia and Chromosome Research Laboratory, Division of Biosciences, Brunel University, London, United Kingdom
| | - Salvatore Saccone
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Biologia Animale, University of Catania, Catania, Italy
- * E-mail:
| |
Collapse
|
32
|
An amino terminal phosphorylation motif regulates intranuclear compartmentalization of Olig2 in neural progenitor cells. J Neurosci 2014; 34:8507-18. [PMID: 24948806 DOI: 10.1523/jneurosci.0309-14.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The bHLH transcription factor Olig2 is expressed in cycling neural progenitor cells but also in terminally differentiated, myelinating oligodendrocytes. Sustained expression of Olig2 is counterintuitive because all known functions of the protein in expansion of neural progenitors and specification of oligodendrocyte progenitors are completed with the formation of mature white matter. How are the biological functions of Olig2 suppressed in terminally differentiated oligodendrocytes? In previous studies, we have shown that a triple serine motif in the amino terminus of Olig2 is phosphorylated in cycling neural progenitors but not in their differentiated progeny. We now show that phosphorylation of the triple serine motif regulates intranuclear compartmentalization of murine Olig2. Phosphorylated Olig2 is preferentially localized to a transcriptionally active "open" chromatin compartment together with coregulator proteins essential for regulation of gene expression. Unphosphorylated Olig2, as seen in mature white matter, is localized mainly within a transcriptionally inactive, chromatin fraction characterized by condensed and inaccessible DNA. Of special note is the observation that the p53 tumor suppressor protein is confined to the open chromatin fraction. Proximity ligation assays show that phosphorylation brings Olig2 within 30 nm of p53 within the open chromatin compartment. The data thus shed light on previously noted promitogenic functions of phosphorylated Olig2, which reflect, at least in part, an oppositional relationship with p53 functions.
Collapse
|
33
|
Olivera-Martinez I, Schurch N, Li RA, Song J, Halley PA, Das RM, Burt DW, Barton GJ, Storey KG. Major transcriptome re-organisation and abrupt changes in signalling, cell cycle and chromatin regulation at neural differentiation in vivo. Development 2014; 141:3266-76. [PMID: 25063452 PMCID: PMC4197544 DOI: 10.1242/dev.112623] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Here, we exploit the spatial separation of temporal events of neural differentiation in the elongating chick body axis to provide the first analysis of transcriptome change in progressively more differentiated neural cell populations in vivo. Microarray data, validated against direct RNA sequencing, identified: (1) a gene cohort characteristic of the multi-potent stem zone epiblast, which contains neuro-mesodermal progenitors that progressively generate the spinal cord; (2) a major transcriptome re-organisation as cells then adopt a neural fate; and (3) increasing diversity as neural patterning and neuron production begin. Focussing on the transition from multi-potent to neural state cells, we capture changes in major signalling pathways, uncover novel Wnt and Notch signalling dynamics, and implicate new pathways (mevalonate pathway/steroid biogenesis and TGFβ). This analysis further predicts changes in cellular processes, cell cycle, RNA-processing and protein turnover as cells acquire neural fate. We show that these changes are conserved across species and provide biological evidence for reduced proteasome efficiency and a novel lengthening of S phase. This latter step may provide time for epigenetic events to mediate large-scale transcriptome re-organisation; consistent with this, we uncover simultaneous downregulation of major chromatin modifiers as the neural programme is established. We further demonstrate that transcription of one such gene, HDAC1, is dependent on FGF signalling, making a novel link between signals that control neural differentiation and transcription of a core regulator of chromatin organisation. Our work implicates new signalling pathways and dynamics, cellular processes and epigenetic modifiers in neural differentiation in vivo, identifying multiple new potential cellular and molecular mechanisms that direct differentiation.
Collapse
Affiliation(s)
- Isabel Olivera-Martinez
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Nick Schurch
- Division of Computational Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Roman A Li
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Junfang Song
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Pamela A Halley
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Raman M Das
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Dave W Burt
- Department of Genomics and Genetics, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Geoffrey J Barton
- Division of Computational Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Kate G Storey
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| |
Collapse
|
34
|
Integration of signals along orthogonal axes of the vertebrate neural tube controls progenitor competence and increases cell diversity. PLoS Biol 2014; 12:e1001907. [PMID: 25026549 PMCID: PMC4098999 DOI: 10.1371/journal.pbio.1001907] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 06/05/2014] [Indexed: 12/21/2022] Open
Abstract
FGF gates competence to generate Floor Plate and Neural Crest in response to Shh and BMP signals by controlling expression of the transcription factor Nkx1.2. A relatively small number of signals are responsible for the variety and pattern of cell types generated in developing embryos. In part this is achieved by exploiting differences in the concentration or duration of signaling to increase cellular diversity. In addition, however, changes in cellular competence—temporal shifts in the response of cells to a signal—contribute to the array of cell types generated. Here we investigate how these two mechanisms are combined in the vertebrate neural tube to increase the range of cell types and deliver spatial control over their location. We provide evidence that FGF signaling emanating from the posterior of the embryo controls a change in competence of neural progenitors to Shh and BMP, the two morphogens that are responsible for patterning the ventral and dorsal regions of the neural tube, respectively. Newly generated neural progenitors are exposed to FGF signaling, and this maintains the expression of the Nk1-class transcription factor Nkx1.2. Ventrally, this acts in combination with the Shh-induced transcription factor FoxA2 to specify floor plate cells and dorsally in combination with BMP signaling to induce neural crest cells. As development progresses, the intersection of FGF with BMP and Shh signals is interrupted by axis elongation, resulting in the loss of Nkx1.2 expression and allowing the induction of ventral and dorsal interneuron progenitors by Shh and BMP signaling to supervene. Hence a similar mechanism increases cell type diversity at both dorsal and ventral poles of the neural tube. Together these data reveal that tissue morphogenesis produces changes in the coincidence of signals acting along orthogonal axes of the neural tube and this is used to define spatial and temporal transitions in the competence of cells to interpret morphogen signaling. During embryonic development different cell types arise at different times and places. This diversity is produced by a relatively small number of signals and depends, at least in part, on changes in the way cells respond to each signal. One example of this so-called change in “competence” is found in the vertebrate spinal cord where a signal, Sonic Hedgehog (Shh), induces a glial cell type known as floor plate (FP) at early developmental times, while the same signal later induces specific types of neurons. Here, we dissected the molecular mechanism underlying the change in competence, and found that another signal, FGF, is involved through its control of the transcription factor Nkx1.2. In embryos, Shh and FGF are produced perpendicular to one another and FP is induced where the two signals intersect. The position of this intersection changes as the embryo elongates and this determines the place and time FP is produced. A similar strategy also appears to apply to another cell type, neural crest. In this case, the intersection of FGF with BMP signal is crucial. Together the data provide new insight into the spatiotemporal control of cell type specification during development of the vertebrate spinal cord.
Collapse
|
35
|
|
36
|
Duester G. Retinoid signaling in control of progenitor cell differentiation during mouse development. Semin Cell Dev Biol 2013; 24:694-700. [PMID: 23973941 DOI: 10.1016/j.semcdb.2013.08.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 07/25/2013] [Accepted: 08/10/2013] [Indexed: 02/01/2023]
Abstract
The vitamin A metabolite retinoic acid (RA) serves as a ligand for nuclear RA receptors that control differentiation of progenitor cells important for vertebrate development. Genetic studies in mouse embryos deficient for RA-generating enzymes have been invaluable for deciphering RA function. RA first begins to act during early organogenesis when RA generated in trunk mesoderm begins to function as a diffusible signal controlling progenitor cell differentiation. In neuroectoderm, RA functions as an instructive signal to stimulate neuronal differentiation of progenitor cells in the hindbrain and spinal cord. RA is not required for early neuronal differentiation of the forebrain, but at later stages RA stimulates neuronal differentiation in forebrain basal ganglia. RA also acts as a permissive signal for differentiation by repressing fibroblast growth factor (FGF) signaling in differentiated cells as they emerge from progenitor populations in the caudal progenitor zone and second heart field. In addition, RA signaling stimulates differentiation of spermatogonial germ cells and induces meiosis in male but not female gonads. A more complete understanding of the normal functions of RA signaling during development will guide efforts to use RA as a differentiation agent for therapeutic purposes.
Collapse
Affiliation(s)
- Gregg Duester
- Sanford-Burnham Medical Research Institute, Development and Aging Program, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
| |
Collapse
|