1
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Wang SX, Streit A. Shared features in ear and kidney development - implications for oto-renal syndromes. Dis Model Mech 2024; 17:dmm050447. [PMID: 38353121 PMCID: PMC10886756 DOI: 10.1242/dmm.050447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
The association between ear and kidney anomalies has long been recognized. However, little is known about the underlying mechanisms. In the last two decades, embryonic development of the inner ear and kidney has been studied extensively. Here, we describe the developmental pathways shared between both organs with particular emphasis on the genes that regulate signalling cross talk and the specification of progenitor cells and specialised cell types. We relate this to the clinical features of oto-renal syndromes and explore links to developmental mechanisms.
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Affiliation(s)
- Scarlet Xiaoyan Wang
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
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2
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Papadogiannis V, Hockman D, Mercurio S, Ramsay C, Hintze M, Patthey C, Streit A, Shimeld SM. Evolution of the expression and regulation of the nuclear hormone receptor ERR gene family in the chordate lineage. Dev Biol 2023; 504:12-24. [PMID: 37696353 DOI: 10.1016/j.ydbio.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/01/2023] [Accepted: 09/09/2023] [Indexed: 09/13/2023]
Abstract
The Estrogen Related Receptor (ERR) nuclear hormone receptor genes have a wide diversity of roles in vertebrate development. In embryos, ERR genes are expressed in several tissues, including the central and peripheral nervous systems. Here we seek to establish the evolutionary history of chordate ERR genes, their expression and their regulation. We examine ERR expression in mollusc, amphioxus and sea squirt embryos, finding the single ERR orthologue is expressed in the nervous system in all three, with muscle expression also found in the two chordates. We show that most jawed vertebrates and lampreys have four ERR paralogues, and that vertebrate ERR genes were ancestrally linked to Estrogen Receptor genes. One of the lamprey paralogues shares conserved expression domains with jawed vertebrate ERRγ in the embryonic vestibuloacoustic ganglion, eye, brain and spinal cord. Hypothesising that conserved expression derives from conserved regulation, we identify a suite of pan-vertebrate conserved non-coding sequences in ERR introns. We use transgenesis in lamprey and chicken embryos to show that these sequences are regulatory and drive reporter gene expression in the nervous system. Our data suggest an ancient association between ERR and the nervous system, including expression in cells associated with photosensation and mechanosensation. This includes the origin in the vertebrate common ancestor of a suite of regulatory elements in the 3' introns that drove nervous system expression and have been conserved from this point onwards.
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Affiliation(s)
| | - Dorit Hockman
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Neuroscience Institute, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Silvia Mercurio
- Department of Environmental Science and Policy, Università Degli Studi di Milano, Via Celoria 2, 20133, Milano, Italy
| | - Claire Ramsay
- Department of Biology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
| | - Mark Hintze
- Centre for Craniofacial & Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
| | - Cedric Patthey
- Department of Radiosciences, Umeå University, 901 85, Umeå, Sweden
| | - Andrea Streit
- Centre for Craniofacial & Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
| | - Sebastian M Shimeld
- Department of Biology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK.
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3
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Leino SA, Constable SCJ, Streit A, Wilkinson DG. Zbtb16 mediates a switch between Fgf signalling regimes in the developing hindbrain. Development 2023; 150:dev201319. [PMID: 37642135 PMCID: PMC10508701 DOI: 10.1242/dev.201319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 08/22/2023] [Indexed: 08/31/2023]
Abstract
Developing tissues are sequentially patterned by extracellular signals that are turned on and off at specific times. In the zebrafish hindbrain, fibroblast growth factor (Fgf) signalling has different roles at different developmental stages: in the early hindbrain, transient Fgf3 and Fgf8 signalling from rhombomere 4 is required for correct segmentation, whereas later, neuronal Fgf20 expression confines neurogenesis to specific spatial domains within each rhombomere. How the switch between these two signalling regimes is coordinated is not known. We present evidence that the Zbtb16 transcription factor is required for this transition to happen in an orderly fashion. Zbtb16 expression is high in the early anterior hindbrain, then gradually upregulated posteriorly and confined to neural progenitors. In mutants lacking functional Zbtb16, fgf3 expression fails to be downregulated and persists until a late stage, resulting in excess and more widespread Fgf signalling during neurogenesis. Accordingly, the spatial pattern of neurogenesis is disrupted in Zbtb16 mutants. Our results reveal how the distinct stage-specific roles of Fgf signalling are coordinated in the zebrafish hindbrain.
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Affiliation(s)
- Sami A. Leino
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London SE1 1UL, UK
| | - Sean C. J. Constable
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London SE1 1UL, UK
| | - David G. Wilkinson
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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4
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Thiery AP, Buzzi AL, Hamrud E, Cheshire C, Luscombe NM, Briscoe J, Streit A. scRNA-sequencing in chick suggests a probabilistic model for cell fate allocation at the neural plate border. eLife 2023; 12:e82717. [PMID: 37530410 PMCID: PMC10425176 DOI: 10.7554/elife.82717] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 08/01/2023] [Indexed: 08/03/2023] Open
Abstract
The vertebrate 'neural plate border' is a transient territory located at the edge of the neural plate containing precursors for all ectodermal derivatives: the neural plate, neural crest, placodes and epidermis. Elegant functional experiments in a range of vertebrate models have provided an in-depth understanding of gene regulatory interactions within the ectoderm. However, these experiments conducted at tissue level raise seemingly contradictory models for fate allocation of individual cells. Here, we carry out single cell RNA sequencing of chick ectoderm from primitive streak to neurulation stage, to explore cell state diversity and heterogeneity. We characterise the dynamics of gene modules, allowing us to model the order of molecular events which take place as ectodermal fates segregate. Furthermore, we find that genes previously classified as neural plate border 'specifiers' typically exhibit dynamic expression patterns and are enriched in either neural, neural crest or placodal fates, revealing that the neural plate border should be seen as a heterogeneous ectodermal territory and not a discrete transitional transcriptional state. Analysis of neural, neural crest and placodal markers reveals that individual NPB cells co-express competing transcriptional programmes suggesting that their ultimate identify is not yet fixed. This population of 'border located undecided progenitors' (BLUPs) gradually diminishes as cell fate decisions take place. Considering our findings, we propose a probabilistic model for cell fate choice at the neural plate border. Our data suggest that the probability of a progenitor's daughters to contribute to a given ectodermal derivative is related to the balance of competing transcriptional programmes, which in turn are regulated by the spatiotemporal position of a progenitor.
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Affiliation(s)
- Alexandre P Thiery
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College LondonLondonUnited Kingdom
| | - Ailin Leticia Buzzi
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College LondonLondonUnited Kingdom
| | - Eva Hamrud
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College LondonLondonUnited Kingdom
| | - Chris Cheshire
- Bioinformatics and Computational Biology Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Nicholas M Luscombe
- Bioinformatics and Computational Biology Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - James Briscoe
- Bioinformatics and Computational Biology Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College LondonLondonUnited Kingdom
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5
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Trevers KE, Lu HC, Yang Y, Thiery AP, Strobl AC, Anderson C, Pálinkášová B, de Oliveira NMM, de Almeida IM, Khan MAF, Moncaut N, Luscombe NM, Dale L, Streit A, Stern CD. A gene regulatory network for neural induction. eLife 2023; 12:73189. [PMID: 36867045 PMCID: PMC10038663 DOI: 10.7554/elife.73189] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 03/02/2023] [Indexed: 03/04/2023] Open
Abstract
During early vertebrate development, signals from a special region of the embryo, the organizer, can redirect the fate of non-neural ectoderm cells to form a complete, patterned nervous system. This is called neural induction and has generally been imagined as a single signalling event, causing a switch of fate. Here, we undertake a comprehensive analysis, in very fine time course, of the events following exposure of competent ectoderm of the chick to the organizer (the tip of the primitive streak, Hensen's node). Using transcriptomics and epigenomics we generate a gene regulatory network comprising 175 transcriptional regulators and 5614 predicted interactions between them, with fine temporal dynamics from initial exposure to the signals to expression of mature neural plate markers. Using in situ hybridization, single-cell RNA-sequencing, and reporter assays, we show that the gene regulatory hierarchy of responses to a grafted organizer closely resembles the events of normal neural plate development. The study is accompanied by an extensive resource, including information about conservation of the predicted enhancers in other vertebrates.
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Affiliation(s)
- Katherine E Trevers
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Hui-Chun Lu
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Youwen Yang
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Alexandre P Thiery
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Anna C Strobl
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Claire Anderson
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Božena Pálinkášová
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Nidia M M de Oliveira
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Irene M de Almeida
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Mohsin A F Khan
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Natalia Moncaut
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Nicholas M Luscombe
- The Francis Crick Institute, London, United Kingdom
- UCL Genetics Institute, Department of Genetics, Environment and Evolution, University College London, London, United Kingdom
| | - Leslie Dale
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Claudio D Stern
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
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Ahmed M, Moon R, Prajapati RS, James E, Basson MA, Streit A. The chromatin remodelling factor Chd7 protects auditory neurons and sensory hair cells from stress-induced degeneration. Commun Biol 2021; 4:1260. [PMID: 34732824 PMCID: PMC8566505 DOI: 10.1038/s42003-021-02788-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 01/19/2021] [Accepted: 10/08/2021] [Indexed: 11/08/2022] Open
Abstract
Neurons and sensory cells are particularly vulnerable to oxidative stress due to their high oxygen demand during stimulus perception and transmission. The mechanisms that protect them from stress-induced death and degeneration remain elusive. Here we show that embryonic deletion of the chromodomain helicase DNA-binding protein 7 (CHD7) in auditory neurons or hair cells leads to sensorineural hearing loss due to postnatal degeneration of both cell types. Mechanistically, we demonstrate that CHD7 controls the expression of major stress pathway components. In its absence, hair cells are hypersensitive, dying rapidly after brief exposure to stress inducers, suggesting that sound at the onset of hearing triggers their degeneration. In humans, CHD7 haploinsufficiency causes CHARGE syndrome, a disorder affecting multiple organs including the ear. Our findings suggest that CHD7 mutations cause developmentally silent phenotypes that predispose cells to postnatal degeneration due to a failure of protective mechanisms.
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Affiliation(s)
- Mohi Ahmed
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK.
| | - Ruth Moon
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK
| | - Ravindra Singh Prajapati
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK
- Leukaemia and Stem Cell Biology Group, School of Cancer and Pharmaceutical Sciences, King's College London, London, SE5 9NU, UK
| | - Elysia James
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE1 1UL, UK
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, SE1 1UL, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK.
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7
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Breeze J, Steel CJ, Streit A, Sarber KM. Characterisation of retained energised fragments from explosive devices in military personnel. BMJ Mil Health 2021; 168:391-394. [PMID: 34131063 DOI: 10.1136/bmjmilitary-2021-001825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 03/01/2021] [Accepted: 05/31/2021] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Characterising the shapes, dimensions and overall numbers of fragments produced by explosive devices is important for determining methods of potential mitigation, such as personal armour. The aim of this investigation was to compare the mass of excised fragments with that predicted from CT to ascertain the validity of using such an approach to measure retained fragments for multiple body areas using CT alone. METHOD 27 retained fragments excised from consecutive patients treated at a US Role 3 Medical Treatment Facility in Afghanistan were examined. Each fragment was measured in three dimensions and the mass was obtained to estimate the density and thereby probable composition. These same excised fragments were identified radiologically and their predicted masses calculated and compared with the known masses with a paired t-test. The total numbers of retained fragments in each of four body areas for 20 casualties were determined radiographically and the mass of the largest fragment in each body region estimated. RESULTS Excised fragments were most commonly metallic (17/27, 63%), with masses ranging from 0.008 to 37.6 g. Mean mass predicted from CT was significantly different from than that measured (p=0.133), with CT underestimating true mass by 5%-17%. 889/958 (93%) retained fragments appeared metallic on imaging, with the most commonly affected body areas being the torso and upper extremity (45% of casualties). CONCLUSIONS Predicting the mass of metallic fragments from CT was possible with an error margin of up to 5%, but was less accurate for non-metallic fragments such as stone. Only 3% of fragments were removed through debridement or purposeful excision; these were not just the largest or most superficial. This suggests that future retrospective analysis of the dimensions and predicted masses of retained fragments in larger casualty cohorts of service personnel is potentially feasible within a small margin of error.
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Affiliation(s)
- John Breeze
- Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, UK .,Department of Bioengineering, Imperial College London, London, UK
| | - C J Steel
- Department of Radiology, US Air Force Academy, Colorado Springs, Colorado, USA
| | - A Streit
- Center for Sustainment of Trauma and Readiness Skills, SSM Health Saint Louis University Hospital, Saint Louis, Missouri, USA
| | - K M Sarber
- Department of Surgery, Uniformed Services University of the Health Sciences F Edward Hebert School of Medicine, Bethesda, Maryland, USA.,Department of Otolaryngology, Eglin Air Force Base, Eglin AFB, Florida, USA
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8
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Stadlbauer V, Negrean I, Posch A, Streit A, Feldbacher N, Stauber RE, Horvath A. Fibroscan® probe selection for lean adults. JGH Open 2021; 5:750-753. [PMID: 34263068 PMCID: PMC8264238 DOI: 10.1002/jgh3.12579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 05/10/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022]
Abstract
Background and Aim Fibroscan® is used to assess fibrosis and steatosis of the liver noninvasively. The company suggests to use the S+‐probe in people <18 years with a thoracic circumference (TC) between 45 and 75 cm and the M+‐probe in children with a TC >75 cm and adults with a skin–liver capsule distance <2.5 cm. For lean adults with a TC ≤75 cm, no comparative studies have been performed. Furthermore, it is unclear whether lean adults need to be fasted before assessment. Methods We compared liver stiffness (LS) using Fibroscan® S+‐ and M+‐probes and controlled attenuation parameter (CAP; only available for M+‐probe) in healthy volunteers with a TC ≤75 cm compared with those with a TC >75 cm in fasting state and after intake of a standardized light meal (300 kcal). Results We examined 50 volunteers (26 female, 24 ± 3 years). Twenty‐two participants were in the TC ≤75 cm group and 28 in TC >75 cm group. LS values with the S+‐probe were 15% higher than with the M+‐probe in both groups (median difference 0.6 kPa, P < 0.001). Both probes showed good agreement with minimal bias (Spearman correlation r = 0.754, P < 0.001; Interclass Correlation Coefficient 0.843, P < 0.001; Bland–Altman bias 0.6 ± 0.9 kPa, linear regression r2 = 0.557, P < 0.001). Intake of a light meal had no relevant influence on LS (S+‐ and M+‐probes) or CAP measurements (M+‐probe) in both groups. Conclusion Lean adults with a TC below 75 cm can be assessed with either the S+‐probe or the M+‐probe and may take a light meal before assessment.
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Affiliation(s)
- Vanessa Stadlbauer
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria
| | - Iohanes Negrean
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria
| | - Andreas Posch
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria
| | - Andrea Streit
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria
| | - Nicole Feldbacher
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria.,Area 3 Cardiometabolic Health Center for Biomarker Research in Medicine (CBmed) Graz Austria
| | - Rudolf E Stauber
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria
| | - Angela Horvath
- Division of Gastroenterology and Hepatology, Department of Internal Medicine Medical University of Graz Graz Austria.,Area 3 Cardiometabolic Health Center for Biomarker Research in Medicine (CBmed) Graz Austria
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9
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Abstract
Vertebrate ear progenitors are induced by fibroblast growth factor signalling, however the molecular mechanisms leading to the coordinate activation of downstream targets are yet to be discovered. The ear, like other sensory placodes, arises from the pre-placodal region at the border of the neural plate. Using a multiplex NanoString approach, we determined the response of these progenitors to FGF signalling by examining the changes of more than 200 transcripts that define the otic and other placodes, neural crest and neural plate territories. This analysis identifies new direct and indirect FGF targets during otic induction. Investigating changes in histone marks by ChIP-seq reveals that FGF exposure of pre-placodal cells leads to rapid deposition of active chromatin marks H3K27ac near FGF-response genes, while H3K27ac is depleted in the vicinity of non-otic genes. Genomic regions that gain H3K27ac act as cis-regulatory elements controlling otic gene expression in time and space and define a unique transcription factor signature likely to control their activity. Finally, we show that in response to FGF signalling the transcription factor dimer AP1 recruits the histone acetyl transferase p300 to selected otic enhancers. Thus, during ear induction FGF signalling modifies the chromatin landscape to promote enhancer activation and chromatin accessibility.
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Affiliation(s)
- Monica Tambalo
- Centre for Craniofacial and Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK
| | - Maryam Anwar
- Centre for Craniofacial and Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK
| | - Mohi Ahmed
- Centre for Craniofacial and Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK.
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10
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Prajapati RS, Hintze M, Streit A. PRDM1 controls the sequential activation of neural, neural crest and sensory progenitor determinants. Development 2019; 146:dev.181107. [PMID: 31806661 DOI: 10.1242/dev.181107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 06/02/2019] [Accepted: 11/27/2019] [Indexed: 12/25/2022]
Abstract
During early embryogenesis, the ectoderm is rapidly subdivided into neural, neural crest and sensory progenitors. How the onset of lineage determinants and the loss of pluripotency markers are temporally and spatially coordinated in vivo is still debated. Here, we identify a crucial role for the transcription factor PRDM1 in the orderly transition from epiblast to defined neural lineages in chick. PRDM1 is initially expressed broadly in the entire epiblast, but becomes gradually restricted as cell fates are specified. We find that PRDM1 is required for the loss of some pluripotency markers and the onset of neural, neural crest and sensory progenitor specifier genes. PRDM1 directly activates their expression by binding to their promoter regions and recruiting the histone demethylase Kdm4a to remove repressive histone marks. However, once neural lineage determinants become expressed, they in turn repress PRDM1, whereas prolonged PRDM1 expression inhibits neural, neural crest and sensory progenitor genes, suggesting that its downregulation is necessary for cells to maintain their identity. Therefore, PRDM1 plays multiple roles during ectodermal cell fate allocation.
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Affiliation(s)
- Ravindra S Prajapati
- Centre for Craniofacial & Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Mark Hintze
- Centre for Craniofacial & Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Andrea Streit
- Centre for Craniofacial & Regenerative Biology, Faculty of Dental, Oral and Craniofacial Sciences, King's College London, London SE1 9RT, UK
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11
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Abstract
Sensory placodes contribute to much of the sensory nervous system in the vertebrate head. They give rise to parts of the eye, ear and nose, as well as to the sensory ganglia that innervate the face, tongue, oesophagus and visceral tissues. Despite their diversity, during development placodes arise from a population of common progenitor cells, which are first specified at the border of the neural plate. The chick has been particularly instrumental in dissecting the timing of these events, and recent evidence has highlighted the close relationship of placode progenitors and precursors for neural crest cells and the central nervous system. This review focuses on the induction of placode progenitors by localised signalling events, and the transcriptional networks that lead to their specification.
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Affiliation(s)
- Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Division of Craniofacial Development and Stem Cell Biology, Dental Institute, King's College London, London UK.
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12
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Schwaneck EC, Streit A, Krone M, Hartmann S, Müller-Richter U, Kübler AC, Gadeholt O, Schmalzing M, Tony HP, Brands RC. Osteoporosis therapy in patients with inflammatory rheumatic diseases and osteonecrosis of the jaw. Z Rheumatol 2019; 79:203-209. [PMID: 30796524 DOI: 10.1007/s00393-019-0606-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES The aim of the present study was to assess the prevalence of medication-related osteonecrosis of the jaw (MRONJ) in osteoporosis patients suffering from inflammatory rheumatic diseases, as well as to assess the prevalence of relevant dental, behavioral, and medical risk factors for MRONJ. MATERIALS AND METHODS A total of 198 patients with inflammatory rheumatic diseases and osteoporosis therapy were recruited from a tertiary rheumatological/immunological referral center between June 2015 and September 2016. They were assessed using a structured interview. A maxillofacial surgeon later examined patients complaining of possible symptoms of osteonecrosis. In cases of osteonecrosis, dental records were obtained and evaluated. Preventive measures taken and dental as well as other clinical risk factors were evaluated. RESULTS Of the 198 patients, three suffered from osteonecrosis of the jaw, none of whom had any history of malignant disease or radiation therapy, resulting in a prevalence of 1.5%. Of these three patients, only one was given bisphosphonates intravenously (i.v.), whereas all three had been treated orally. All three diagnoses of MRONJ had been previously known to the patients and their maxillofacial surgeons. Two of the patients had rheumatoid arthritis, and one patient suffered from large vessel vasculitis. Long anti-osteoporotic treatment duration, low functional status, and low bone density of the femur were significantly associated with MRONJ development. CONCLUSION Inflammatory rheumatic diseases constitute a risk factor for MRONJ in patients treated with bisphosphonates for osteoporosis. Patients should be counseled accordingly and should be offered dental screening and regular dental check-ups.
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Affiliation(s)
- E C Schwaneck
- Department of Rheumatology and Immunology (Head: H.-P. Tony), University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany.
| | - A Streit
- Department of Rheumatology and Immunology (Head: H.-P. Tony), University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - M Krone
- Institute for Hygiene and Microbiology, University of Wuerzburg, Josef-Schneider-Straße 2, 97080, Würzburg, Germany
| | - S Hartmann
- Department of Oral and Maxillofacial Plastic Surgery (Head: A.C. Kübler), University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - U Müller-Richter
- Department of Oral and Maxillofacial Plastic Surgery (Head: A.C. Kübler), University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - A C Kübler
- Department of Oral and Maxillofacial Plastic Surgery (Head: A.C. Kübler), University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - O Gadeholt
- Department of Rheumatology and Immunology (Head: H.-P. Tony), University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - M Schmalzing
- Department of Rheumatology and Immunology (Head: H.-P. Tony), University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - H-P Tony
- Department of Rheumatology and Immunology (Head: H.-P. Tony), University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - R C Brands
- Department of Oral and Maxillofacial Plastic Surgery (Head: A.C. Kübler), University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
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13
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Ahmed M, Streit A. Lsd1 interacts with cMyb to demethylate repressive histone marks and maintain inner ear progenitor identity. Development 2018; 145:dev.160325. [PMID: 29437831 DOI: 10.1242/dev.160325] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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: 10/07/2017] [Accepted: 01/20/2018] [Indexed: 01/30/2023]
Abstract
During development, multipotent progenitor cells must maintain their identity while retaining the competence to respond to new signalling cues that drive cell fate decisions. This depends on both DNA-bound transcription factors and surrounding histone modifications. Here, we identify the histone demethylase Lsd1 as a crucial component of the molecular machinery that preserves progenitor identity in the developing ear prior to lineage commitment. Although Lsd1 is mainly associated with repressive complexes, we show that, in ear precursors, it is required to maintain active transcription of otic genes. We reveal a novel interaction between Lsd1 and the transcription factor cMyb, which in turn recruits Lsd1 to the promoters of key ear transcription factors. Here, Lsd1 prevents the accumulation of repressive H3K9me2, while allowing H3K9 acetylation. Loss of Lsd1 function causes rapid silencing of active promoters and loss of ear progenitor genes, and shuts down the entire ear developmental programme. Our data suggest that Lsd1-cMyb acts as a co-activator complex that maintains a regulatory module at the top of the inner ear gene network.
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Affiliation(s)
- Mohi Ahmed
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, Dental Institute, King's College London, London SE1 9RT, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, Dental Institute, King's College London, London SE1 9RT, UK
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14
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Stauber RE, Fauler G, Rainer F, Leber B, Posch A, Streit A, Spindelboeck W, Stadlbauer V, Kessler HH, Mangge H. Anti-HCV treatment with ombitasvir/paritaprevir/ritonavir ± dasabuvir is associated with increased bile acid levels and pruritus. Wien Klin Wochenschr 2017; 129:848-851. [DOI: 10.1007/s00508-017-1268-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/30/2017] [Indexed: 11/24/2022]
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15
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Hintze M, Prajapati RS, Tambalo M, Christophorou NAD, Anwar M, Grocott T, Streit A. Cell interactions, signals and transcriptional hierarchy governing placode progenitor induction. Development 2017; 144:2810-2823. [PMID: 28684624 PMCID: PMC5560042 DOI: 10.1242/dev.147942] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 06/21/2017] [Indexed: 12/18/2022]
Abstract
In vertebrates, cranial placodes contribute to all sense organs and sensory ganglia and arise from a common pool of Six1/Eya2+ progenitors. Here we dissect the events that specify ectodermal cells as placode progenitors using newly identified genes upstream of the Six/Eya complex. We show in chick that two different tissues, namely the lateral head mesoderm and the prechordal mesendoderm, gradually induce placode progenitors: cells pass through successive transcriptional states, each identified by distinct factors and controlled by different signals. Both tissues initiate a common transcriptional state but over time impart regional character, with the acquisition of anterior identity dependent on Shh signalling. Using a network inference approach we predict the regulatory relationships among newly identified transcription factors and verify predicted links in knockdown experiments. Based on this analysis we propose a new model for placode progenitor induction, in which the initial induction of a generic transcriptional state precedes regional divergence.
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Affiliation(s)
- Mark Hintze
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
| | - Ravindra Singh Prajapati
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
| | - Monica Tambalo
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
| | - Nicolas A D Christophorou
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
| | - Maryam Anwar
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
| | - Timothy Grocott
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
| | - Andrea Streit
- Department of Craniofacial Development & Stem Cell Biology, King's College London, Dental Institute, London SE1 9RT, UK
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16
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Chen J, Tambalo M, Barembaum M, Ranganathan R, Simões-Costa M, Bronner ME, Streit A. A systems-level approach reveals new gene regulatory modules in the developing ear. Development 2017; 144:1531-1543. [PMID: 28264836 PMCID: PMC5399671 DOI: 10.1242/dev.148494] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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: 12/20/2016] [Accepted: 02/24/2017] [Indexed: 01/23/2023]
Abstract
The inner ear is a complex vertebrate sense organ, yet it arises from a simple epithelium, the otic placode. Specification towards otic fate requires diverse signals and transcriptional inputs that act sequentially and/or in parallel. Using the chick embryo, we uncover novel genes in the gene regulatory network underlying otic commitment and reveal dynamic changes in gene expression. Functional analysis of selected transcription factors reveals the genetic hierarchy underlying the transition from progenitor to committed precursor, integrating known and novel molecular players. Our results not only characterize the otic transcriptome in unprecedented detail, but also identify new gene interactions responsible for inner ear development and for the segregation of the otic lineage from epibranchial progenitors. By recapitulating the embryonic programme, the genes and genetic sub-circuits discovered here might be useful for reprogramming naïve cells towards otic identity to restore hearing loss. Summary: Transcriptome analysis and knock down of select transcription factors reveals a genetic hierarchy as cells become committed to inner ear fate.
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Affiliation(s)
- Jingchen Chen
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London SE1 9RT, UK
| | - Monica Tambalo
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London SE1 9RT, UK
| | - Meyer Barembaum
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ramya Ranganathan
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London SE1 9RT, UK
| | - Marcos Simões-Costa
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London SE1 9RT, UK
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17
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Abstract
Cranial placodes contribute to sensory structures including the inner ear, the lens and olfactory epithelium and the neurons of the cranial sensory ganglia. At neurula stages, placode precursors are interspersed in the ectoderm surrounding the anterior neural plate before segregating into distinct placodes by as yet unknown mechanisms. Here, we perform live imaging to follow placode progenitors as they aggregate to form the lens and otic placodes. We find that while placode progenitors move with the same speed as their non-placodal neighbours, they exhibit increased persistence and directionality and these properties are required to assemble morphological placodes. Furthermore, we demonstrate that these factors are components of the transcriptional networks that coordinate placode cell behaviour including their directional movements. Together with previous work, our results support a dual role for Otx and Gbx transcription factors in both the early patterning of the neural plate border and the later segregation of its derivatives into distinct placodes. Summary: Using spatial and temporally controlled perturbations followed by live cell tracking in vivo, this paper demonstrates that directional movements downstream of Gbx2 and Otx2 are important for otic and lens placode formation.
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Affiliation(s)
- Ben Steventon
- Department of Craniofacial Development, King's College London, Guy's Campus, Tower Wing Floor 27, London SE1 9RT, UK .,Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Roberto Mayor
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Andrea Streit
- Department of Craniofacial Development, King's College London, Guy's Campus, Tower Wing Floor 27, London SE1 9RT, UK
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18
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Spindelboeck W, Horvath A, Tawdrous M, Schmerböck B, Zettel G, Posch A, Streit A, Jurse P, Lemesch S, Horn M, Wuensch G, Stiegler P, Stauber RE, Leber B, Stadlbauer V. Triple Therapy with First Generation Protease Inhibitors for Hepatitis C Markedly Impairs Function of Neutrophil Granulocytes. PLoS One 2016; 11:e0150299. [PMID: 26938078 PMCID: PMC4777445 DOI: 10.1371/journal.pone.0150299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/11/2016] [Indexed: 01/01/2023] Open
Abstract
First-generation HCV protease inhibitors represent a milestone in antiviral therapy for chronic hepatitis C infection (CHC), but substantially increased rates of viral clearance are offset by increased rates of infection and infection-associated deaths, especially of patients with advanced liver disease. We aimed to assess whether first generation protease inhibitors interfere with neutrophil function. We included 108 consecutive, retrospective CHC patients and 44 consecutive, prospective CHC patients who were treated with peginterferon and ribavirin with or without protease inhibitors according to the guidelines in the period of November 2012 to June 2015. 33 healthy volunteers served as controls. Infection data were evaluated in all patients. Neutrophil phagocytosis, oxidative burst, elastase and diamine oxidase levels during 12 weeks of triple (n = 23) or dual therapy (n = 21) were studied in the prospective part. In the retro- and prospective cohorts patients experiencing clinically relevant infections were significantly more frequent during protease inhibitor therapy (31% and 26%) than during therapy with peginterferon and ribavirin (13% and 0%). Neutrophil phagocytosis decreased to 40% of baseline with addition of protease inhibitors to P/R but recovered 6 months after end of treatment. Protease inhibitors also seemed to reduce serum elastase levels but did not impact on gut permeability. Impaired neutrophil function during triple therapy with first generation HCV protease inhibitors may explain the high infection rate associated to these treatments and be of relevance for treatment success and patient survival.
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Affiliation(s)
- Walter Spindelboeck
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Angela Horvath
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Monika Tawdrous
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Bianca Schmerböck
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Graz, Austria
| | - Gabriele Zettel
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Graz, Austria
| | - Andreas Posch
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Andrea Streit
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Petra Jurse
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Sandra Lemesch
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Martin Horn
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Gerit Wuensch
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Philipp Stiegler
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Graz, Austria
| | - Rudolf E. Stauber
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Bettina Leber
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Vanessa Stadlbauer
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
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19
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Abstract
Background Enhancers are key elements to control gene expression in time and space and thus orchestrate gene function during development, homeostasis, and disease. Whole genome approaches and bioinformatic predictions have generated a tremendous pool of potential enhancers, however their spatiotemporal activity often remains to be validated in vivo. Despite recent progress in developing high throughput strategies for enhancer evaluation, these remain mainly restricted to invertebrates and in vitro cell culture. Results Here we design a medium‐scale method to validate potential enhancers in an amniote embryo, the chick. Using a unique barcode for different reporter vectors allows us to detect the activity of nine separate enhancers in a single embryo by one‐step RT‐PCR. The assay is sufficiently sensitive to expand its capacity further by generating additional barcoded vectors. Conclusions As a rapid, sensitive, and cost‐effective way to assess enhancer activity in an amniote vertebrate, this method provides a major advance and a useful alternative to the generation of transgenic animals. Developmental Dynamics 244:1291–1299, 2015. © 2015 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists Design of a new strategy for rapid enhancer validation in an amniote embryo, the chick. Generation of a simple vector for rapid cloning. The activity of many enhancers can be detected in a single embryo using a PCR‐based strategy. The assay is sufficiently sensitive to detect activity in a small fraction of cells.
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Affiliation(s)
- Jingchen Chen
- Department of Craniofacial Development and Stem Cell Biology, Dental Institute, King's College London, London, United Kingdom
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, Dental Institute, King's College London, London, United Kingdom
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20
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Ahmed M, Ura K, Streit A. Auditory hair cell defects as potential cause for sensorineural deafness in Wolf-Hirschhorn syndrome. Dis Model Mech 2015; 8:1027-35. [PMID: 26092122 PMCID: PMC4582100 DOI: 10.1242/dmm.019547] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [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: 12/17/2014] [Accepted: 06/10/2015] [Indexed: 02/04/2023] Open
Abstract
WHSC1 is a histone methyltransferase (HMT) that catalyses the addition of methyl groups to lysine 36 on histone 3. In humans, WHSC1 haploinsufficiency is associated with all known cases of Wolf-Hirschhorn syndrome (WHS). The cardinal feature of WHS is a craniofacial dysmorphism, which is accompanied by sensorineural hearing loss in 15% of individuals with WHS. Here, we show that WHSC1-deficient mice display craniofacial defects that overlap with WHS, including cochlea anomalies. Although auditory hair cells are specified normally, their stereocilia hair bundles required for sound perception fail to develop the appropriate morphology. Furthermore, the orientation and cellular organisation of cochlear hair cells and their innervation are defective. These findings identify, for the first time, the likely cause of sensorineural hearing loss in individuals with WHS.
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Affiliation(s)
- Mohi Ahmed
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London, SE1 9RT, UK
| | - Kiyoe Ura
- Laboratory of Chromatin Metabolism and Epigenetics, Graduate School of Science, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London, SE1 9RT, UK
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21
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Shida H, Mende M, Takano-Yamamoto T, Osumi N, Streit A, Wakamatsu Y. Otic placode cell specification and proliferation are regulated by Notch signaling in avian development. Dev Dyn 2015; 244:839-51. [PMID: 25970828 DOI: 10.1002/dvdy.24291] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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: 10/16/2014] [Revised: 04/26/2015] [Accepted: 05/01/2015] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND The entire inner ear including the cochlear-vestibular ganglion arises from a simple epithelium, the otic placode. Precursors for the placode originate from a pool of progenitors located in ectoderm next to the future hindbrain, the pre-otic field, where they are intermingled with future epibranchial and epidermal cells. While the importance of secreted proteins, such as FGFs and Wnts, in imparting otic identity has been well studied, how precursors for these different fates segregate locally is less well understood. RESULTS (1) The Notch ligand Delta1 and the Notch target Hes5-2 are expressed in a part of pre-otic field before otic commitment, indicative of active Notch signaling, and this is confirmed using a Notch reporter. (2) Loss and gain-of-function approaches reveal that Notch signaling regulates both proliferation and specification of pre-otic progenitors. CONCLUSIONS Our results identify a novel function of Notch signaling in cell fate determination in the pre-otic field of avian embryos.
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Affiliation(s)
- Hiroko Shida
- Department of Developmental Neuroscience, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, Miyagi, Japan.,Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Miyagi, Japan
| | - Michael Mende
- Department of Craniofacial Development and Stem Cell Biology, King's College London
| | - Teruko Takano-Yamamoto
- Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Miyagi, Japan
| | - Noriko Osumi
- Department of Developmental Neuroscience, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King's College London
| | - Yoshio Wakamatsu
- Department of Developmental Neuroscience, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, Miyagi, Japan
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22
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Yan B, Neilson KM, Ranganathan R, Maynard T, Streit A, Moody SA. Microarray identification of novel genes downstream of Six1, a critical factor in cranial placode, somite, and kidney development. Dev Dyn 2014; 244:181-210. [PMID: 25403746 DOI: 10.1002/dvdy.24229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [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: 06/05/2014] [Revised: 11/03/2014] [Accepted: 11/12/2014] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Six1 plays an important role in the development of several vertebrate organs, including cranial sensory placodes, somites, and kidney. Although Six1 mutations cause one form of branchio-otic syndrome (BOS), the responsible gene in many patients has not been identified; genes that act downstream of Six1 are potential BOS candidates. RESULTS We sought to identify novel genes expressed during placode, somite and kidney development by comparing gene expression between control and Six1-expressing ectodermal explants. The expression patterns of 19 of the significantly up-regulated and 11 of the significantly down-regulated genes were assayed from cleavage to larval stages. A total of 28/30 genes are expressed in the otocyst, a structure that is functionally disrupted in BOS, and 26/30 genes are expressed in the nephric mesoderm, a structure that is functionally disrupted in the related branchio-otic-renal (BOR) syndrome. We also identified the chick homologues of five genes and show that they have conserved expression patterns. CONCLUSIONS Of the 30 genes selected for expression analyses, all are expressed at many of the developmental times and appropriate tissues to be regulated by Six1. Many have the potential to play a role in the disruption of hearing and kidney function seen in BOS/BOR patients.
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Affiliation(s)
- Bo Yan
- Department of Anatomy and Regenerative Biology, The George Washington University, School of Medicine and Health Sciences, Washington, DC
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23
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Som PM, Streit A, Naidich TP. Illustrated review of the embryology and development of the facial region, part 3: an overview of the molecular interactions responsible for facial development. AJNR Am J Neuroradiol 2014; 35:223-9. [PMID: 23557958 DOI: 10.3174/ajnr.a3453] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
SUMMARY Parts 1 and 2 of this review discussed the complex morphogenesis of the face. However, the molecular processes that drive the morphology of the face were not addressed. Part 3 of this review will present an overview of the genes and their products that have been implicated in the developing face.
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Affiliation(s)
- P M Som
- From the Department of Radiology (P.M.S., T.P.N.), Mount Sinai School of Medicine, New York University, New York, New York
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24
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Steventon B, Mayor R, Streit A. Neural crest and placode interaction during the development of the cranial sensory system. Dev Biol 2014; 389:28-38. [PMID: 24491819 DOI: 10.1016/j.ydbio.2014.01.021] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [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: 11/01/2013] [Revised: 01/19/2014] [Accepted: 01/25/2014] [Indexed: 01/13/2023]
Abstract
In the vertebrate head, the peripheral components of the sensory nervous system are derived from two embryonic cell populations, the neural crest and cranial sensory placodes. Both arise in close proximity to each other at the border of the neural plate: neural crest precursors abut the future central nervous system, while placodes originate in a common preplacodal region slightly more lateral. During head morphogenesis, complex events organise these precursors into functional sensory structures, raising the question of how their development is coordinated. Here we review the evidence that neural crest and placode cells remain in close proximity throughout their development and interact repeatedly in a reciprocal manner. We also review recent controversies about the relative contribution of the neural crest and placodes to the otic and olfactory systems. We propose that a sequence of mutual interactions between the neural crest and placodes drives the coordinated morphogenesis that generates functional sensory systems within the head.
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Affiliation(s)
- Ben Steventon
- Department of Developmental and Stem Cell Biology, Insitut Pasteur, France
| | - Roberto Mayor
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King׳s College London, London, UK.
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25
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Abstract
Tissue transplantation is an important approach in developmental neurobiology to determine cell fate, to uncover inductive interactions required for tissue specification and patterning as well as to establish tissue competence and commitment. Avian species are among the favorite model systems for these approaches because of their accessibility and relatively large size. Here we describe two culture techniques used to generate quail-chick chimeras at different embryonic stages and methods to distinguish graft and donor tissue.
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Affiliation(s)
- Andrea Streit
- Department of Craniofacial Development & Stem Cell Biology, King's College London, London, UK
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26
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Papanayotou C, De Almeida I, Liao P, Oliveira NMM, Lu SQ, Kougioumtzidou E, Zhu L, Shaw A, Sheng G, Streit A, Yu D, Wah Soong T, Stern CD. Calfacilitin is a calcium channel modulator essential for initiation of neural plate development. Nat Commun 2013; 4:1837. [PMID: 23673622 PMCID: PMC3674269 DOI: 10.1038/ncomms2864] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [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: 09/14/2012] [Accepted: 04/10/2013] [Indexed: 11/09/2022] Open
Abstract
Calcium fluxes have been implicated in the specification of the vertebrate embryonic nervous system for some time, but how these fluxes are regulated and how they relate to the rest of the neural induction cascade is unknown. Here we describe Calfacilitin, a transmembrane calcium channel facilitator that increases calcium flux by generating a larger window current and slowing inactivation of the L-type CaV1.2 channel. Calfacilitin binds to this channel and is co-expressed with it in the embryo. Regulation of intracellular calcium by Calfacilitin is required for expression of the neural plate specifiers Geminin and Sox2 and for neural plate formation. Loss-of-function of Calfacilitin can be rescued by ionomycin, which increases intracellular calcium. Our results elucidate the role of calcium fluxes in early neural development and uncover a new factor in the modulation of calcium signalling.
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Affiliation(s)
- Costis Papanayotou
- Department of Cell and Developmental Biology, University College London, Gower Street (Anatomy Building), London WC1E 6BT, UK.
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27
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Lleras-Forero L, Tambalo M, Christophorou N, Chambers D, Houart C, Streit A. Neuropeptides: developmental signals in placode progenitor formation. Dev Cell 2013; 26:195-203. [PMID: 23906067 PMCID: PMC3748341 DOI: 10.1016/j.devcel.2013.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 02/20/2013] [Accepted: 07/02/2013] [Indexed: 02/02/2023]
Abstract
Few families of signaling factors have been implicated in the control of development. Here, we identify the neuropeptides nociceptin and somatostatin, a neurotransmitter and neuroendocrine hormone, as a class of developmental signals in both chick and zebrafish. We show that signals from the anterior mesendoderm are required for the formation of anterior placode progenitors, with one of the signals being somatostatin. Somatostatin controls ectodermal expression of nociceptin, and both peptides regulate Pax6 in lens and olfactory progenitors. Consequently, loss of somatostatin and nociceptin signaling leads to severe reduction of lens formation. Our findings not only uncover these neuropeptides as developmental signals but also identify a long-sought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutionary origin of neuropeptides, predating a complex nervous system.
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Affiliation(s)
- Laura Lleras-Forero
- Department of Craniofacial Development and Stem Cell Biology, King’s College London, Guy’s Tower Wing, Floor 27, London SE1 9RT, UK
| | - Monica Tambalo
- Department of Craniofacial Development and Stem Cell Biology, King’s College London, Guy’s Tower Wing, Floor 27, London SE1 9RT, UK
| | - Nicolas Christophorou
- Department of Craniofacial Development and Stem Cell Biology, King’s College London, Guy’s Tower Wing, Floor 27, London SE1 9RT, UK
| | - David Chambers
- MRC Centre for Developmental Neurobiology, King’s College London, New Hunts House, London SE1 1UL, UK
| | - Corinne Houart
- MRC Centre for Developmental Neurobiology, King’s College London, New Hunts House, London SE1 1UL, UK
| | - Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King’s College London, Guy’s Tower Wing, Floor 27, London SE1 9RT, UK
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28
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Theveneau E, Steventon B, Scarpa E, Garcia S, Trepat X, Streit A, Mayor R. Chase-and-run between adjacent cell populations promotes directional collective migration. Nat Cell Biol 2013; 15:763-72. [PMID: 23770678 PMCID: PMC4910871 DOI: 10.1038/ncb2772] [Citation(s) in RCA: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/30/2013] [Indexed: 12/03/2022]
Abstract
Collective cell migration in morphogenesis and cancer progression often involves the coordination of multiple cell types. How reciprocal interactions between adjacent cell populations lead to new emergent behaviours remains unknown. Here we studied the interaction between Neural Crest (NC) cells, a highly migratory cell population, and placodal cells, an epithelial tissue that contributes to sensory organs. We found that NC cells “chase” placodal cells by chemotaxis, while placodal cells “run” when contacted by NC. Chemotaxis to Sdf1 underlies the chase, while repulsion involving PCP and N-Cadherin signalling is responsible for the run. This “chase-and-run” requires the generation of asymmetric forces, which depend on local inhibition of focal adhesions. The cell interactions described here are essential for correct NC migration and for segregation of placodes in vivo and are likely to represent a general mechanism of coordinated migration.
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Affiliation(s)
- Eric Theveneau
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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29
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Khan MAF, Soto-Jimenez LM, Howe T, Streit A, Sosinsky A, Stern CD. Computational tools and resources for prediction and analysis of gene regulatory regions in the chick genome. Genesis 2013; 51:311-24. [PMID: 23355428 PMCID: PMC3664090 DOI: 10.1002/dvg.22375] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 01/16/2013] [Accepted: 01/17/2013] [Indexed: 11/07/2022]
Abstract
The discovery of cis-regulatory elements is a challenging problem in bioinformatics, owing to distal locations and context-specific roles of these elements in controlling gene regulation. Here we review the current bioinformatics methodologies and resources available for systematic discovery of cis-acting regulatory elements and conserved transcription factor binding sites in the chick genome. In addition, we propose and make available, a novel workflow using computational tools that integrate CTCF analysis to predict putative insulator elements, enhancer prediction, and TFBS analysis. To demonstrate the usefulness of this computational workflow, we then use it to analyze the locus of the gene Sox2 whose developmental expression is known to be controlled by a complex array of cis-acting regulatory elements. The workflow accurately predicts most of the experimentally verified elements along with some that have not yet been discovered. A web version of the CTCF tool, together with instructions for using the workflow can be accessed from http://toolshed.g2.bx.psu.edu/view/mkhan1980/ctcf_analysis. For local installation of the tool, relevant Perl scripts and instructions are provided in the directory named "code" in the supplementary materials.
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Affiliation(s)
- Mohsin A F Khan
- Department of Cell & Developmental Biology, University College London, London, United Kingdom
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30
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Streit A, Tambalo M, Chen J, Grocott T, Anwar M, Sosinsky A, Stern CD. Experimental approaches for gene regulatory network construction: the chick as a model system. Genesis 2012; 51:296-310. [PMID: 23174848 DOI: 10.1002/dvg.22359] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 11/09/2012] [Accepted: 11/11/2012] [Indexed: 01/23/2023]
Abstract
Setting up the body plan during embryonic development requires the coordinated action of many signals and transcriptional regulators in a precise temporal sequence and spatial pattern. The last decades have seen an explosion of information describing the molecular control of many developmental processes. The next challenge is to integrate this information into logic "wiring diagrams" that visualize gene actions and outputs, have predictive power and point to key control nodes. Here, we provide an experimental workflow on how to construct gene regulatory networks using the chick as model system.
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Affiliation(s)
- Andrea Streit
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London, United Kingdom.
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31
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Abstract
Despite its complexity in the adult, during development the inner ear arises from a simple epithelium, the otic placode. Placode specification is a multistep process that involves the integration of various signalling pathways and downstream transcription factors in time and space. Here we review the molecular events that successively commit multipotent ectodermal precursors to the otic lineage. The first step in this hierarchy is the specification of sensory progenitor cells, which can contribute to all sensory placodes, followed by the induction of a common otic-epibranchial field and finally the establishment the otic territory. In recent years, some of the molecular components that control this process have been identified, and begin to reveal complex interactions. Future studies will need to unravel how this information is integrated and encoded in the genome. This will form the blueprint for stem cell differentiation towards otic fates and generate a predictive gene regulatory network that models the earliest steps of otic specification.
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Affiliation(s)
- Jingchen Chen
- Department of Craniofacial Development and Stem Cell Biology, King's College London, Guy's Tower Wing, Floor 27, London SE1 9RT, UK
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32
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Grocott T, Tambalo M, Streit A. The peripheral sensory nervous system in the vertebrate head: a gene regulatory perspective. Dev Biol 2012; 370:3-23. [PMID: 22790010 DOI: 10.1016/j.ydbio.2012.06.028] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 02/06/2023]
Abstract
In the vertebrate head, crucial parts of the sense organs and sensory ganglia develop from special regions, the cranial placodes. Despite their cellular and functional diversity, they arise from a common field of multipotent progenitors and acquire distinct identity later under the influence of local signalling. Here we present the gene regulatory network that summarises our current understanding of how sensory cells are specified, how they become different from other ectodermal derivatives and how they begin to diversify to generate placodes with different identities. This analysis reveals how sequential activation of sets of transcription factors subdivides the ectoderm over time into smaller domains of progenitors for the central nervous system, neural crest, epidermis and sensory placodes. Within this hierarchy the timing of signalling and developmental history of each cell population is of critical importance to determine the ultimate outcome. A reoccurring theme is that local signals set up broad gene expression domains, which are further refined by mutual repression between different transcription factors. The Six and Eya network lies at the heart of sensory progenitor specification. In a positive feedback loop these factors perpetuate their own expression thus stabilising pre-placodal fate, while simultaneously repressing neural and neural crest specific factors. Downstream of the Six and Eya cassette, Pax genes in combination with other factors begin to impart regional identity to placode progenitors. While our review highlights the wealth of information available, it also points to the lack information on the cis-regulatory mechanisms that control placode specification and of how the repeated use of signalling input is integrated.
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Affiliation(s)
- Timothy Grocott
- Department of Craniofacial Development and Stem Cell Biology, King's College London, Guy's Tower Wing, Floor 27, London SE1 9RT, UK
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33
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Lleras-Forero L, Streit A. Development of the sensory nervous system in the vertebrate head: the importance of being on time. Curr Opin Genet Dev 2012; 22:315-22. [PMID: 22726669 DOI: 10.1016/j.gde.2012.05.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/30/2012] [Accepted: 05/15/2012] [Indexed: 12/18/2022]
Abstract
Sense organs and cranial sensory ganglia are functionally diverse, yet share a common developmental origin. They arise from a pool of multipotent progenitors and local signals gradually restrict their development potential to specify the inner ear, olfactory epithelium, lens and sensory neurons. This process requires the temporal integration of multiple signalling pathways, cross-repressive transcription factor interactions and tight coordination of cell fate specification and morphogenesis.
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Affiliation(s)
- Laura Lleras-Forero
- Department of Craniofacial Development and Stem Cell Biology, King's College London, London SE1 9RT, UK
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34
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Sabado V, Barraud P, Baker CVH, Streit A. Specification of GnRH-1 neurons by antagonistic FGF and retinoic acid signaling. Dev Biol 2011; 362:254-62. [PMID: 22200593 DOI: 10.1016/j.ydbio.2011.12.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 12/08/2011] [Accepted: 12/09/2011] [Indexed: 11/25/2022]
Abstract
A small population of neuroendocrine cells in the rostral hypothalamus and basal forebrain is the key regulator of vertebrate reproduction. They secrete gonadotropin-releasing hormone (GnRH-1), communicate with many areas of the brain and integrate multiple inputs to control gonad maturation, puberty and sexual behavior. In humans, disruption of the GnRH-1 system leads to hypogonadotropic gonadism and Kallmann syndrome. Unlike other neurons in the central nervous system, GnRH-1 neurons arise in the periphery, however their embryonic origin is controversial, and the molecular mechanisms that control their initial specification are not clear. Here, we provide evidence that in chick GnRH-1 neurons originate in the olfactory placode, where they are specified shortly after olfactory sensory neurons. FGF signaling is required and sufficient to induce GnRH-1 neurons, while retinoic acid represses their formation. Both pathways regulate and antagonize each other and our results suggest that the timing of signaling is critical for normal GnRH-1 neuron formation. While Kallmann's syndrome has generally been attributed to a failure of GnRH-1 neuron migration due to impaired FGF signaling, our findings suggest that in at least some Kallmann patients these neurons may never be specified. In addition, this study highlights the intimate embryonic relationship between GnRH-1 neurons and their targets and modulators in the adult.
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Affiliation(s)
- Virginie Sabado
- Department of Craniofacial Development, King's College London, Guy's Campus, London, SE1 9RT, UK
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35
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Gibson A, Robinson N, Streit A, Sheng G, Stern CD. Regulation of programmed cell death during neural induction in the chick embryo. Int J Dev Biol 2011; 55:33-43. [PMID: 21305469 DOI: 10.1387/ijdb.103233sg] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To study early responses to neural inducing signals from the organizer (Hensen's node), a differential screen was performed in primitive streak stage chick embryos, comparing cells that had or had not been exposed to a node graft for 5 hours. Three of the genes isolated have been implicated in Programmed Cell Death (PCD): Defender Against Cell Death (Dad1), Polyubiquitin II (UbII) and Ferritin Heavy chain (fth1). We therefore explored the potential involvement of PCD in neural induction. Dad1, UbII and fth1 are expressed in partly overlapping domains during early neural plate development, along with the pro-apoptotic gene Cas9 and the death effector Cas3. Dad1 and UbII are induced by a node graft within 3 hours. TUNEL staining revealed that PCD is initially random, but both during normal development and following neural induction by a grafted node, it becomes concentrated at the border of the forming neural plate and anterior non-neural ectoderm and downregulated from the neural plate itself. PCD was observed in regions of Caspase expression that are free from Dad1, consistent with the known anti-apoptotic role of Dad1. However, gain- and loss-of-function of any of these genes had no detectable effect on cell identity or on neural plate development. This study reveals that early development of the neural plate is accompanied by induction of putative pro- and anti-apoptotic genes in distinct domains. We suggest that the neural plate is protected against apoptosis, confining cell death to its border and adjacent non-neural ectoderm.
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Affiliation(s)
- Anna Gibson
- Department of Cell and Developmental Biology, University College London, London, UK
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36
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Grocott T, Johnson S, Bailey AP, Streit A. Neural crest cells organize the eye via TGF-β and canonical Wnt signalling. Nat Commun 2011; 2:265. [PMID: 21468017 PMCID: PMC3104559 DOI: 10.1038/ncomms1269] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [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: 10/18/2010] [Accepted: 03/09/2011] [Indexed: 01/12/2023] Open
Abstract
In vertebrates, the lens and retina arise from different embryonic tissues raising the question of how they are aligned to form a functional eye. Neural crest cells are crucial for this process: in their absence, ectopic lenses develop far from the retina. Here we show, using the chick as a model system, that neural crest-derived transforming growth factor-βs activate both Smad3 and canonical Wnt signalling in the adjacent ectoderm to position the lens next to the retina. They do so by controlling Pax6 activity: although Smad3 may inhibit Pax6 protein function, its sustained downregulation requires transcriptional repression by Wnt-initiated β-catenin. We propose that the same neural crest-dependent signalling mechanism is used repeatedly to integrate different components of the eye and suggest a general role for the neural crest in coordinating central and peripheral parts of the sensory nervous system. In the developing eye, the lens and retina are derived from different embryonic tissues, and how these two structures develop next to each other is of interest. In this study, the authors show that transforming growth factor-β secreted by neural crest cells is critical for the positioning of the lens next to the retina.
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Affiliation(s)
- Timothy Grocott
- Department of Craniofacial Development, King's College London, Guy's Campus, London SE1 9RT, UK
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37
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Pinho S, Simonsson PR, Trevers KE, Stower MJ, Sherlock WT, Khan M, Streit A, Sheng G, Stern CD. Distinct steps of neural induction revealed by Asterix, Obelix and TrkC, genes induced by different signals from the organizer. PLoS One 2011; 6:e19157. [PMID: 21559472 PMCID: PMC3084772 DOI: 10.1371/journal.pone.0019157] [Citation(s) in RCA: 21] [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: 12/06/2010] [Accepted: 03/21/2011] [Indexed: 01/19/2023] Open
Abstract
The amniote organizer (Hensen's node) can induce a complete nervous system when grafted into a peripheral region of a host embryo. Although BMP inhibition has been implicated in neural induction, non-neural cells cannot respond to BMP antagonists unless previously exposed to a node graft for at least 5 hours before BMP inhibitors. To define signals and responses during the first 5 hours of node signals, a differential screen was conducted. Here we describe three early response genes: two of them, Asterix and Obelix, encode previously undescribed proteins of unknown function but Obelix appears to be a nuclear RNA-binding protein. The third is TrkC, a neurotrophin receptor. All three genes are induced by a node graft within 4-5 hours but they differ in the extent to which they are inducible by FGF: FGF is both necessary and sufficient to induce Asterix, sufficient but not necessary to induce Obelix and neither sufficient nor necessary for induction of TrkC. These genes are also not induced by retinoic acid, Noggin, Chordin, Dkk1, Cerberus, HGF/SF, Somatostatin or ionomycin-mediated Calcium entry. Comparison of the expression and regulation of these genes with other early neural markers reveals three distinct "epochs", or temporal waves, of gene expression accompanying neural induction by a grafted organizer, which are mirrored by specific stages of normal neural plate development. The results are consistent with neural induction being a cascade of responses elicited by different signals, culminating in the formation of a patterned nervous system.
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Affiliation(s)
- Sonia Pinho
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Pamela R. Simonsson
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Katherine E. Trevers
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Matthew J. Stower
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - William T. Sherlock
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Mohsin Khan
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Andrea Streit
- Department of Craniofacial Development, King's College London, London, United Kingdom
| | - Guojun Sheng
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Claudio D. Stern
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
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38
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Dias AS, Streit A, Stern CD. O27. Somite formation without a clock. Differentiation 2010. [DOI: 10.1016/j.diff.2010.09.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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39
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Christophorou NAD, Mende M, Lleras-Forero L, Grocott T, Streit A. Pax2 coordinates epithelial morphogenesis and cell fate in the inner ear. Dev Biol 2010; 345:180-90. [PMID: 20643116 PMCID: PMC2946559 DOI: 10.1016/j.ydbio.2010.07.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 07/02/2010] [Accepted: 07/06/2010] [Indexed: 01/04/2023]
Abstract
Crucial components of the vertebrate eye, ear and nose develop from discrete patches of surface epithelium, called placodes, which fold into spheroids and undergo complex morphogenesis. Little is known about how the changes in cell and tissue shapes are coordinated with the acquisition of cell fates. Here we explore whether these processes are regulated by common transcriptional mechanisms in the developing ear. After specification, inner ear precursors elongate to form the placode, which invaginates and is transformed into the complex structure of the adult ear. We show that the transcription factor Pax2 plays a key role in coordinating otic fate and placode morphogenesis, but appears to regulate each process independently. In the absence of Pax2, otic progenitors not only lose otic marker expression, but also fail to elongate due to the loss of apically localised N-cadherin and N-CAM. In the absence of either N-cadherin or N-CAM otic cells lose apical cell–cell contact and their epithelial shape. While misexpression of Pax2 leads to ectopic activation of both adhesion molecules, it is not sufficient to confer otic identity. These observations suggest that Pax2 controls cell shape independently from cell identity and thus acts as coordinator for these processes.
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40
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Christophorou NAD, Bailey AP, Hanson S, Streit A. Activation of Six1 target genes is required for sensory placode formation. Dev Biol 2009; 336:327-36. [PMID: 19781543 DOI: 10.1016/j.ydbio.2009.09.025] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 09/16/2009] [Accepted: 09/16/2009] [Indexed: 10/20/2022]
Abstract
In vertebrates, cranial placodes form crucial parts of the sensory nervous system in the head. All cranial placodes arise from a common territory, the preplacodal region, and are identified by the expression of Six1/4 and Eya1/2 genes, which control different aspects of sensory development in invertebrates as well as vertebrates. While So and Eya can induce ectopic eyes in Drosophila, the ability of their vertebrate homologues to induce placodes in non-placodal ectoderm has not been explored. Here we show that Six1 and Eya2 are involved in ectodermal patterning and cooperate to induce preplacodal gene expression, while repressing neural plate and neural crest fates. However, they are not sufficient to induce ectopic sensory placodes in future epidermis. Activation of Six1 target genes is required for expression of preplacodal genes, for normal placode morphology and for placode-specific Pax protein expression. These findings suggest that unlike in the fly where the Pax6 homologue Eyeless acts upstream of Six and Eya, the regulatory relationships between these genes are reversed in early vertebrate placode development.
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Affiliation(s)
- Nicolas A D Christophorou
- Department of Craniofacial Development, King's College London, Guy's Campus, Tower Wing Floor 27, London SE1 8RT, UK
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41
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Papanayotou C, Liao P, Lu SQ, Zhu L, Shaw A, Streit A, Yu D, Soong TW, Stern CD, Sheng G. S04-01 Calfacilitin: A new player in neural induction. Mech Dev 2009. [DOI: 10.1016/j.mod.2009.06.1058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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42
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Sabado V, Streit A. 13-P085 Origin and molecular control of GnRH neuron formation. Mech Dev 2009. [DOI: 10.1016/j.mod.2009.06.558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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43
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Mende M, Christophorou NAD, Streit A. Specific and effective gene knock-down in early chick embryos using morpholinos but not pRFPRNAi vectors. Mech Dev 2008; 125:947-62. [PMID: 18801428 DOI: 10.1016/j.mod.2008.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 08/21/2008] [Accepted: 08/25/2008] [Indexed: 11/24/2022]
Abstract
In the chick embryo, two methods are now used for studying the developmental role of genes by loss-of-function approaches: vector-based shRNA and morpholino oligonucleotides. Both have the advantage that loss-of-function can be conducted in a spatially and temporally controlled way by focal electroporation. Here, we compare these two methods. We find that the shRNA expressing vectors pRFPRNAi, even when targeting a non-expressed protein like GFP, cause morphological phenotypes, mis-regulation of non-targeted genes and activation of the p53 pathway. These effects are highly reproducible, appear to be independent of the targeting sequence and are particularly severe at primitive streak and early somite stages. By contrast, morpholinos do not cause these effects. We propose that pRFPRNAi should only be used with considerable caution and that morpholinos are a preferable approach for gene knock-down during early chick development.
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Affiliation(s)
- Michael Mende
- Department of Craniofacial Development, King's College London, Guy's Campus, Guy's Tower Floor 27, London SE1 9RT, UK
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44
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Streit A, Christophorou N, Lleras L. Molecular networks controlling the specification of sensory organ progenitors. Dev Biol 2008. [DOI: 10.1016/j.ydbio.2008.05.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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45
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Streit A. The preplacodal region: an ectodermal domain with multipotential progenitors that contribute to sense organs and cranial sensory ganglia. Int J Dev Biol 2008; 51:447-61. [PMID: 17891708 DOI: 10.1387/ijdb.072327as] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The otic primordium belongs to a group of related structures, the sensory placodes that contribute to the paired sense organs - ear, eye and olfactory epithelium - and to the distal parts of the cranial sensory ganglia. Recent evidence suggests that despite their diversity, all placodes share a common developmental origin and a common molecular mechanism which initiates their formation. At the base of placode induction lies the specification of a unique "placode field", termed the preplacodal region and acquisition of this "preplacodal state" is required for ectodermal cells to undergo otic development. Here I review the molecular mechanisms that sequentially subdivide the ectoderm to give rise to the placode territory.
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Affiliation(s)
- Andrea Streit
- Department of Craniofacial Development, King's College London, Guy's Campus, London, UK.
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46
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47
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Affiliation(s)
- Andrea Streit
- Department of Craniofacial Development, King's College London, London, UK
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48
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Streit A, Bailey A, Bhattacharyya S, Bronner-Fraser M. Lens: A ground state for all sensory placodes and its inhibition by FGF and neural crest derived signals. Dev Biol 2007. [DOI: 10.1016/j.ydbio.2007.03.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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49
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Liu W, Lagutin OV, Mende M, Streit A, Oliver G. Six3 activation of Pax6 expression is essential for mammalian lens induction and specification. EMBO J 2006; 25:5383-95. [PMID: 17066077 PMCID: PMC1636621 DOI: 10.1038/sj.emboj.7601398] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 09/26/2006] [Indexed: 01/31/2023] Open
Abstract
The homeobox gene Six3 regulates forebrain development. Here we show that Six3 is also crucial for lens formation. Conditional deletion of mouse Six3 in the presumptive lens ectoderm (PLE) disrupted lens formation. In the most severe cases, lens induction and specification were defective, and the lens placode and lens were absent. In Six3-mutant embryos, Pax6 was downregulated, and Sox2 was absent in the lens preplacodal ectoderm. Using ChIP, electrophoretic mobility shift assay, and luciferase reporter assays, we determined that Six3 activates Pax6 and Sox2 expression. Misexpression of mouse Six3 into chick embryos promoted the ectopic expansion of the ectodermal Pax6 expression domain. Our results position Six3 at the top of the regulatory pathway leading to lens formation. We conclude that Six3 directly activates Pax6 and probably also Sox2 in the PLE and regulates cell autonomously the earliest stages of mammalian lens induction.
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Affiliation(s)
- Wei Liu
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Oleg V Lagutin
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael Mende
- Department of Craniofacial Development, King's College London, London, UK
| | - Andrea Streit
- Department of Craniofacial Development, King's College London, London, UK
| | - Guillermo Oliver
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN, USA
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50
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Bailey AP, Bhattacharyya S, Bronner-Fraser M, Streit A. Lens Specification Is the Ground State of All Sensory Placodes, from which FGF Promotes Olfactory Identity. Dev Cell 2006; 11:505-17. [PMID: 17011490 DOI: 10.1016/j.devcel.2006.08.009] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Revised: 07/15/2006] [Accepted: 08/18/2006] [Indexed: 11/29/2022]
Abstract
The sense organs of the vertebrate head comprise structures as varied as the eye, inner ear, and olfactory epithelium. In the early embryo, these assorted structures share a common developmental origin within the preplacodal region and acquire specific characteristics only later. Here we demonstrate a fundamental similarity in placodal precursors: in the chick all are specified as lens prior to acquiring features of specific sensory or neurogenic placodes. Lens specification becomes progressively restricted in the head ectoderm, initially by FGF and subsequently by signals derived from migrating neural crest cells. We show that FGF8 from the anterior neural ridge is both necessary and sufficient to promote olfactory fate in adjacent ectoderm. Our results reveal that placode precursors share a common ground state as lens and progressive restriction allows the full range of placodal derivatives to form.
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Affiliation(s)
- Andrew P Bailey
- Department of Craniofacial Development, King's College London, Guy's Campus, London SE1 9RT, United Kingdom
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