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Harley P, Kerins C, Gatt A, Neves G, Riccio F, Machado CB, Cheesbrough A, R'Bibo L, Burrone J, Lieberam I. Aberrant axon initial segment plasticity and intrinsic excitability of ALS hiPSC motor neurons. Cell Rep 2023; 42:113509. [PMID: 38019651 DOI: 10.1016/j.celrep.2023.113509] [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: 05/04/2023] [Revised: 10/06/2023] [Accepted: 11/13/2023] [Indexed: 12/01/2023] Open
Abstract
Dysregulated neuronal excitability is a hallmark of amyotrophic lateral sclerosis (ALS). We sought to investigate how functional changes to the axon initial segment (AIS), the site of action potential generation, could impact neuronal excitability in ALS human induced pluripotent stem cell (hiPSC) motor neurons. We find that early TDP-43 and C9orf72 hiPSC motor neurons show an increase in the length of the AIS and impaired activity-dependent AIS plasticity that is linked to abnormal homeostatic regulation of neuronal activity and intrinsic hyperexcitability. In turn, these hyperactive neurons drive increased spontaneous myofiber contractions of in vitro hiPSC motor units. In contrast, late hiPSC and postmortem ALS motor neurons show AIS shortening, and hiPSC motor neurons progress to hypoexcitability. At a molecular level, aberrant expression of the AIS master scaffolding protein ankyrin-G and AIS-specific voltage-gated sodium channels mirror these dynamic changes in AIS function and excitability. Our results point toward the AIS as an important site of dysfunction in ALS motor neurons.
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Affiliation(s)
- Peter Harley
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK; UCL Queen Square Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL, London, UK
| | - Caoimhe Kerins
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK; Centre for Craniofacial & Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Ariana Gatt
- Queen Square Brain Bank, Department of Neurodegenerative Disease, Institute of Neurology, University College London, London WC1N 1PJ, UK
| | - Guilherme Neves
- Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK
| | - Federica Riccio
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK
| | - Carolina Barcellos Machado
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK
| | - Aimee Cheesbrough
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK
| | - Lea R'Bibo
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK
| | - Juan Burrone
- Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, Kings College London, London SE1 1UL, UK.
| | - Ivo Lieberam
- Centre for Gene Therapy & Regenerative Medicine, Kings College London, London SE1 9RT, UK; Centre for Developmental Neurobiology, Kings College London, London SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, Kings College London, London SE1 1UL, UK.
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Williams J, Hurling C, Munir S, Harley P, Machado CB, Cujba AM, Alvarez-Fallas M, Danovi D, Lieberam I, Sancho R, Beales P, Watt FM. Modelling renal defects in Bardet-Biedl syndrome patients using human iPS cells. Front Cell Dev Biol 2023; 11:1163825. [PMID: 37333983 PMCID: PMC10272764 DOI: 10.3389/fcell.2023.1163825] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/19/2023] [Indexed: 06/20/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a ciliopathy with pleiotropic effects on multiple tissues, including the kidney. Here we have compared renal differentiation of iPS cells from healthy and BBS donors. High content image analysis of WT1-expressing kidney progenitors showed that cell proliferation, differentiation and cell shape were similar in healthy, BBS1, BBS2, and BBS10 mutant lines. We then examined three patient lines with BBS10 mutations in a 3D kidney organoid system. The line with the most deleterious mutation, with low BBS10 expression, expressed kidney marker genes but failed to generate 3D organoids. The other two patient lines expressed near normal levels of BBS10 mRNA and generated multiple kidney lineages within organoids when examined at day 20 of organoid differentiation. However, on prolonged culture (day 27) the proximal tubule compartment degenerated. Introducing wild type BBS10 into the most severely affected patient line restored organoid formation, whereas CRISPR-mediated generation of a truncating BBS10 mutation in a healthy line resulted in failure to generate organoids. Our findings provide a basis for further mechanistic studies of the role of BBS10 in the kidney.
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Affiliation(s)
- James Williams
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Chloe Hurling
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Sabrina Munir
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Peter Harley
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Carolina Barcellos Machado
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Ana-Maria Cujba
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Mario Alvarez-Fallas
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Davide Danovi
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
- Bit.bio, Babraham Research Campus, Cambridge, United Kingdom
| | - Ivo Lieberam
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
- Centre for Developmental Neurobiology and MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| | - Rocio Sancho
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Philip Beales
- Institute of Child Health, Genetic and Genomic Medicine, University College London, London, United Kingdom
| | - Fiona M. Watt
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
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Berzanskyte I, Riccio F, Machado CB, Bradbury EJ, Lieberam I. Enrichment of human embryonic stem cell-derived V3 interneurons using an Nkx2-2 gene-specific reporter. Sci Rep 2023; 13:2008. [PMID: 36737643 PMCID: PMC9898512 DOI: 10.1038/s41598-023-29165-z] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
V3 spinal interneurons are a key element of the spinal circuits, which control motor function. However, to date, there are no effective ways of deriving a pure V3 population from human pluripotent stem cells. Here, we report a method for differentiation and isolation of spinal V3 interneurons, combining extrinsic factor-mediated differentiation and magnetic activated cell sorting. We found that differentiation of V3 progenitors can be enhanced with a higher concentration of Sonic Hedgehog agonist, as well as culturing cells in 3D format. To enable V3 progenitor purification from mixed differentiation cultures, we developed a transgene reporter, with a part of the regulatory region of V3-specific gene Nkx2-2 driving the expression of a membrane marker CD14. We found that in human cells, NKX2-2 initially exhibited co-labelling with motor neuron progenitor marker, but V3 specificity emerged as the differentiation culture progressed. At these later differentiation timepoints, we were able to enrich V3 progenitors labelled with CD14 to ~ 95% purity, and mature them to postmitotic V3 interneurons. This purification tool for V3 interneurons will be useful for in vitro disease modeling, studies of normal human neural development and potential cell therapies for disorders of the spinal cord.
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Affiliation(s)
- Ieva Berzanskyte
- Centre for Gene Therapy and Regenerative Medicine, Centre for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, King's College London, 28th Floor Tower Wing, Guy's Campus, Great Maze Pond, London, SE1 9RT, UK.
- The Wolfson Centre for Age-Related Diseases, King's College London, London, UK.
| | - Federica Riccio
- Centre for Gene Therapy and Regenerative Medicine, Centre for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, King's College London, 28th Floor Tower Wing, Guy's Campus, Great Maze Pond, London, SE1 9RT, UK
| | - Carolina Barcellos Machado
- Centre for Gene Therapy and Regenerative Medicine, Centre for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, King's College London, 28th Floor Tower Wing, Guy's Campus, Great Maze Pond, London, SE1 9RT, UK
| | | | - Ivo Lieberam
- Centre for Gene Therapy and Regenerative Medicine, Centre for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, King's College London, 28th Floor Tower Wing, Guy's Campus, Great Maze Pond, London, SE1 9RT, UK.
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Pessoa FMCP, Machado CB, Barreto IV, Gadelha RB, Ribeiro RM, Oliveira DS, Filho MOM, Montenegro RC, Moraes MEA, Moreira-Nunes CA. EPIDEMIOLOGICAL AND MOLECULAR PROFILE OF PATIENTS WITH ACUTE MIELOID LEUKEMIA IN CEARÁ. Hematol Transfus Cell Ther 2022. [DOI: 10.1016/j.htct.2022.09.281] [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: 11/11/2022] Open
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Pessoa FMCP, Machado CB, Barreto IV, Gadelha RB, Ribeiro RM, Oliveira DS, Filho MOM, Montenegro RC, Moraes MEA, Moreira-Nunes CA. EPIDEMIOLOGICAL AND MOLECULAR PROFILE OF ADULT PATIENTS WITH ACUTE LYMPHOBLASTIC LEUKEMIA IN CEARÁ. Hematol Transfus Cell Ther 2022. [DOI: 10.1016/j.htct.2022.09.282] [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: 11/07/2022] Open
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6
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Machado CB, Silva EL, Portilho AJS, Moraes MEA, Filho MOM, Montenegro RC, Souza LEB, Moreira-Nunes CA. PARP INHIBITION INDUCES PHILADEPHIA P190 POSITIVE ACUTE LYMPHOID LEUKEMIA CELL DEATH IN LEVELS SIMILAR TO IMATINIB TREATMENT. Hematol Transfus Cell Ther 2022. [DOI: 10.1016/j.htct.2022.09.249] [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: 11/11/2022] Open
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7
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Machado CB, Rocha da Silva C, Daiana Barroso F, Campos RDS, Valente Sá LGDA, S Aires do Nascimento FB, Cavalcanti BC, Vitoriano Nobre Júnior H, Andrade Neto JB. In vitro evaluation of anti-fungal activity of tropicamide against strains of Candida spp. resistant to fluconazole in planktonic and biofilm form. J Mycol Med 2021; 31:101080. [PMID: 33278803 DOI: 10.1016/j.mycmed.2020.101080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 09/12/2020] [Accepted: 11/03/2020] [Indexed: 01/08/2023]
Abstract
Candida spp. is considered to be the third or fourth most common cause of bloodstream infections associated with healthcare services in the world. Currently, several strains exhibit resistance to the traditional treatments, making the development of new therapeutic molecules necessary. Drug repositioning is an alternative that can be used to work around problems such as toxicity, cost and time in the development of new drugs. This study aims to evaluate the in vitro antifungal effect of tropicamide, molecule of anticholinergic action, against planktonic cells of Candida spp. and biofilm of C. albicans. Six strains of different Candida species were used to determine the minimum inhibitory concentration (MIC) of tropicamide and fluconazole according to CLSI document M27-A3 and one strain of C. albicans was used to evaluate the activity of tropicamide against biofilms. In concentrations of 64μg/mL, the tropicamide exhibited 50% of inhibitory activity in planktonic cell and in concentrations of 128μg/mL is able to inhibit the formation of C. albicans biofilm. Despite the inhibitory activity shown at the present study, the use of a larger number of strains, as well as in vivo cytotoxicity assays, is necessary to confirm the hypothesis that tropicamide can be used as an adjuvant agent in the treatment of infections by the Candida genus.
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Affiliation(s)
- C B Machado
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Christus University Centre (UNICHRISTUS), Fortaleza, CE, Brazil
| | - C Rocha da Silva
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Drug research and development centre, Federal university of Ceará, Fortaleza, CE, Brazil
| | - F Daiana Barroso
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil
| | - R D S Campos
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Christus University Centre (UNICHRISTUS), Fortaleza, CE, Brazil
| | - L G D A Valente Sá
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Drug research and development centre, Federal university of Ceará, Fortaleza, CE, Brazil
| | - F B S Aires do Nascimento
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Drug research and development centre, Federal university of Ceará, Fortaleza, CE, Brazil
| | - B C Cavalcanti
- Drug research and development centre, Federal university of Ceará, Fortaleza, CE, Brazil
| | - H Vitoriano Nobre Júnior
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Drug research and development centre, Federal university of Ceará, Fortaleza, CE, Brazil
| | - J B Andrade Neto
- School of pharmacy, laboratory of bioprospection in antimicrobial molecules (LABIMAN), Federal University of Ceará, Fortaleza, CE, Brazil; Christus University Centre (UNICHRISTUS), Fortaleza, CE, Brazil.
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Machado CB, Pluchon P, Harley P, Rigby M, Gonzalez Sabater V, Stevenson DC, Hynes S, Lowe A, Burrone J, Viasnoff V, Lieberam I. In Vitro Modelling of Nerve-Muscle Connectivity in a Compartmentalised Tissue Culture Device. Adv Biosyst 2019; 3:1800307. [PMID: 31428672 PMCID: PMC6699992 DOI: 10.1002/adbi.201800307] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Indexed: 01/02/2023]
Abstract
Motor neurons project axons from the hindbrain and spinal cord to muscle, where they induce myofibre contractions through neurotransmitter release at neuromuscular junctions. Studies of neuromuscular junction formation and homeostasis have been largely confined to in vivo models. In this study we have merged three powerful tools - pluripotent stem cells, optogenetics and microfabrication - and designed an open microdevice in which motor axons grow from a neural compartment containing embryonic stem cell-derived motor neurons and astrocytes through microchannels to form functional neuromuscular junctions with contractile myofibers in a separate compartment. Optogenetic entrainment of motor neurons in this reductionist neuromuscular circuit enhanced neuromuscular junction formation more than two-fold, mirroring the activity-dependence of synapse development in vivo. We incorporated an established motor neuron disease model into our system and found that coculture of motor neurons with SOD1G93A astrocytes resulted in denervation of the central compartment and diminished myofiber contractions, a phenotype which was rescued by the Receptor Interacting Serine/Threonine Kinase 1 (RIPK1) inhibitor Necrostatin. This coculture system replicates key aspects of nerve-muscle connectivity in vivo and represents a rapid and scalable alternative to animal models of neuromuscular function and disease.
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Affiliation(s)
- Carolina Barcellos Machado
- Centre for Stem Cells and Regenerative Medicine, King’s
College London, London SE1 9RT, UK; Centre for Developmental
Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s
College London, London SE1 1UL, UK
| | - Perrine Pluchon
- Centre for Stem Cells and Regenerative Medicine, King’s
College London, London SE1 9RT, UK; Centre for Developmental
Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s
College London, London SE1 1UL, UK; Mechanobiology Institute, National
University of Singapore, Singapore 117411
| | - Peter Harley
- Centre for Stem Cells and Regenerative Medicine, King’s College London, London SE1 9RT, UK; Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | | | - Victoria Gonzalez Sabater
- Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | | | - Stephanie Hynes
- Centre for Stem Cells and Regenerative Medicine, King’s College London, London SE1 9RT, UK; Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | - Andrew Lowe
- Centre for Developmental Neurobiology, King’s College London, London SE1 1UL, UK
| | - Juan Burrone
- Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore,
Singapore 117411
| | - Ivo Lieberam
- Centre for Stem Cells and Regenerative Medicine, King’s
College London, London SE1 9RT, UK; Centre for Developmental
Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s
College London, London SE1 1UL, UK
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Bryson JB, Machado CB, Crossley M, Stevenson D, Bros-Facer V, Burrone J, Greensmith L, Lieberam I. Optical control of muscle function by transplantation of stem cell-derived motor neurons in mice. Science 2014; 344:94-7. [PMID: 24700859 DOI: 10.1126/science.1248523] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Damage to the central nervous system caused by traumatic injury or neurological disorders can lead to permanent loss of voluntary motor function and muscle paralysis. Here, we describe an approach that circumvents central motor circuit pathology to restore specific skeletal muscle function. We generated murine embryonic stem cell-derived motor neurons that express the light-sensitive ion channel channelrhodopsin-2, which we then engrafted into partially denervated branches of the sciatic nerve of adult mice. These engrafted motor neurons not only reinnervated lower hind-limb muscles but also enabled their function to be restored in a controllable manner using optogenetic stimulation. This synthesis of regenerative medicine and optogenetics may be a successful strategy to restore muscle function after traumatic injury or disease.
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Affiliation(s)
- J Barney Bryson
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, UK
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Machado CB, Kanning KC, Kreis P, Stevenson D, Crossley M, Nowak M, Iacovino M, Kyba M, Chambers D, Blanc E, Lieberam I. Reconstruction of phrenic neuron identity in embryonic stem cell-derived motor neurons. Development 2014; 141:784-94. [PMID: 24496616 PMCID: PMC3912827 DOI: 10.1242/dev.097188] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Air breathing is an essential motor function for vertebrates living on land. The rhythm that drives breathing is generated within the central nervous system and relayed via specialised subsets of spinal motor neurons to muscles that regulate lung volume. In mammals, a key respiratory muscle is the diaphragm, which is innervated by motor neurons in the phrenic nucleus. Remarkably, relatively little is known about how this crucial subtype of motor neuron is generated during embryogenesis. Here, we used direct differentiation of motor neurons from mouse embryonic stem cells as a tool to identify genes that direct phrenic neuron identity. We find that three determinants, Pou3f1, Hoxa5 and Notch, act in combination to promote a phrenic neuron molecular identity. We show that Notch signalling induces Pou3f1 in developing motor neurons in vitro and in vivo. This suggests that the phrenic neuron lineage is established through a local source of Notch ligand at mid-cervical levels. Furthermore, we find that the cadherins Pcdh10, which is regulated by Pou3f1 and Hoxa5, and Cdh10, which is controlled by Pou3f1, are both mediators of like-like clustering of motor neuron cell bodies. This specific Pcdh10/Cdh10 activity might provide the means by which phrenic neurons are assembled into a distinct nucleus. Our study provides a framework for understanding how phrenic neuron identity is conferred and will help to generate this rare and inaccessible yet vital neuronal subtype directly from pluripotent stem cells, thus facilitating subsequent functional investigations.
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Machado CB, Silva Neto LC, Loreto V, Souza MJ. B chromosome prevalence and physical mapping of 18S rDNA and H4 histone sites in the grasshopper Xyleus discoideus angulatus (Romaleidae). Genet Mol Res 2014; 13:7052-60. [PMID: 24737517 DOI: 10.4238/2014.march.26.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We sampled 11 natural populations of the grasshopper Xyleus discoideus angulatus in Northeastern Brazil to analyze B chromosome frequency and meiotic behavior. We observed a single large B chromosome, resembling the X chromosome, in 29 of the 402 specimens. Eight of the 11 populations had B chromosomes, with a rather broad geographical distribution, suggesting that this is an ancient polymorphism; significant differences were observed in B chromosome prevalence among the populations. Presence of the B chromosome was associated with increased frequency of macrospermatids. Fluorescent in situ hybridization revealed 18S rDNA sites in the pericentromeric regions of the X and L3 chromosomes, although some populations had an additional locus on the M4 chromosome. No variation was found for chromosome location of H4 histone genes, which were always observed in paracentromeric regions of the L2, M4 and X chromosomes, a rather unusual location compared to locations known from the families Acrididae and Proscopiidae. These B chromosomes lacked these two kinds of repetitive DNA, at least in amounts that can be visualized by fluorescent in situ hybridization, suggesting that these B chromosomes did not originate from any of the four chromosomes carrying rDNA or H4 histone genes.
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Affiliation(s)
- C B Machado
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brasil
| | - L C Silva Neto
- Departamento de Genética, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, PE, Brasil
| | - V Loreto
- Departamento de Genética, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, PE, Brasil
| | - M J Souza
- Departamento de Genética, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, PE, Brasil
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12
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Machado CB, Kanning KC, Kreis P, Stevenson D, Crossley M, Nowak M, Iacovino M, Kyba M, Chambers D, Blanc E, Lieberam I. Reconstruction of phrenic neuron identity in embryonic stem cell-derived motor neurons. Development 2014. [DOI: 10.1242/dev.108803] [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: 11/20/2022]
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Machado CB, Ventura JMG, Lemos AF, Ferreira JMF, Leite MF, Goes AM. 3D chitosan-gelatin-chondroitin porous scaffold improves osteogenic differentiation of mesenchymal stem cells. Biomed Mater 2007; 2:124-31. [PMID: 18458445 DOI: 10.1088/1748-6041/2/2/010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A porous 3D scaffold was developed to support and enhance the differentiation process of mesenchymal stem cells (MSC) into osteoblasts in vitro. The 3D scaffold was made with chitosan, gelatin and chondroitin and it was crosslinked by EDAC. The scaffold physicochemical properties were evaluated. SEM revealed the high porosity and interconnection of pores in the scaffold; rheological measurements show that the scaffold exhibits a characteristic behavior of strong gels. The elastic modulus found in compressive tests of the crosslinked scaffold was about 50 times higher than the non-crosslinked one. After 21 days, the 3D matrix submitted to hydrolytic degradation loses above 40% of its weight. MSC were collected from rat bone marrow and seeded in chitosan-gelatin-chondroitin 3D scaffolds and in 2D culture plates as well. MSC were differentiated into osteoblasts for 21 days. Cell proliferation and alkaline phosphatase activity were followed weekly during the osteogenic process. The osteogenic differentiation of MSC was improved in 3D culture as shown by MTT assay and alkaline phosphatase activity. On the 21st day, bone markers, osteopontin and osteocalcin, were detected by the PCR analysis. This study shows that the chitosan-gelatin-chondroitin 3D structure provides a good environment for the osteogenic process and enhances cellular proliferation.
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Affiliation(s)
- C B Machado
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Brazil
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14
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Medrado GCB, Machado CB, Valerio P, Sanches MD, Goes AM. The effect of a chitosan–gelatin matrix and dexamethasone on the behavior of rabbit mesenchymal stem cells. Biomed Mater 2006; 1:155-61. [DOI: 10.1088/1748-6041/1/3/010] [Citation(s) in RCA: 25] [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] [Indexed: 02/08/2023]
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Lima SL, Machado CB, Pereira MA, Cara DC, Velarde DT, Andrade SP, Gontijo CM. Immunization by subcutaneous implants of polyester-polyurethane sponges coupled with antigen. Braz J Med Biol Res 1999; 32:443-7. [PMID: 10347808 DOI: 10.1590/s0100-879x1999000400011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 11/22/2022] Open
Abstract
A new protocol is described for immunization of outbred Swiss mice. The procedure is based on subcutaneous implantation of antigen-coupled polyester-polyurethane sponges cut into disks of 10 mm in diameter vs 2 mm in thickness. Antigen coupling was performed by overnight incubation of the sponge with a solution of ovalbumin (Ova) (2 mg/ml) diluted in sodium carbonate buffer, pH 9.6. The amount of ovalbumin that was taken up by the sponge was between 71.4 to 82.5 micrograms. This was estimated by comparing the Ova absorbance at 280 nm in coating buffer solutions before and after incubation. To compare the efficiency of the proposed method, experimental groups immunized with the antigen in the presence of adjuvants (10 micrograms in Al(OH)3 or 100 micrograms in complete Freund's adjuvant (CFA)) were run in parallel. The data obtained after the 3rd week of immunization indicate that both cellular and humoral immune responses were achieved. These were assayed by antigen-induced footpad swelling and ELISA (specific antibodies), respectively. The levels of both immune responses elicited were similar to the responses observed in mice immunized with ovalbumin in the presence of Al(OH)3. The method might represent an advantage when immunizing with pathogenic antigens. Preliminary experiments have suggested that the antigen remains immobilized or bound to the sponge for a long period of time, since there is an increment on the cell population inside the sponges after boosting the animals. If so, the undesirable effects of immunization would be reduced.
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Affiliation(s)
- S L Lima
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
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