1
|
Ramanayake S, Moulding DA, Tanaka Y, Singh A, Bangham CRM. Dynamics and consequences of the HTLV-1 proviral plus-strand burst. PLoS Pathog 2022; 18:e1010774. [PMID: 36441826 PMCID: PMC9731428 DOI: 10.1371/journal.ppat.1010774] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/08/2022] [Accepted: 11/15/2022] [Indexed: 11/30/2022] Open
Abstract
Expression of the transcriptional transactivator protein Tax, encoded on the proviral plus-strand of human T-cell leukaemia virus type 1 (HTLV-1), is crucial for the replication of the virus, but Tax-expressing cells are rarely detected in fresh blood ex vivo. The dynamics and consequences of the proviral plus-strand transcriptional burst remain insufficiently characterised. We combined time-lapse live-cell imaging, single-cell tracking and mathematical modelling to study the dynamics of Tax expression at single-cell resolution in two naturally-infected, non-malignant T-cell clones transduced with a short-lived enhanced green fluorescent protein (d2EGFP) Tax reporter system. Five different patterns of Tax expression were observed during the 30-hour observation period; the distribution of these patterns differed between the two clones. The mean duration of Tax expression in the two clones was 94 and 417 hours respectively, estimated from mathematical modelling of the experimental data. Tax expression was associated with a transient slowing in cell-cycle progression and proliferation, increased apoptosis, and enhanced activation of the DNA damage response pathways. Longer-term follow-up (14 days) revealed an increase in the proportion of proliferating cells and a decrease in the fraction of apoptotic cells as the cells ceased Tax expression, resulting in a greater net expansion of the initially Tax-positive population. Time-lapse live-cell imaging showed enhanced cell-to-cell adhesion among Tax-expressing cells, and decreased cell motility of Tax-expressing cells at the single-cell level. The results demonstrate the within-clone and between-clone heterogeneity in the dynamics and patterns of HTLV-1 plus-strand transcriptional bursts and the balance of positive and negative consequences of the burst for the host cell.
Collapse
Affiliation(s)
- Saumya Ramanayake
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Dale A. Moulding
- Light Microscopy Core Facility, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Yuetsu Tanaka
- Department of Infectious Disease and Immunology, Okinawa-Asia Research Center of Medical Science, Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware, United States of America
| | - Charles R. M. Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
2
|
Mason WJ, Jafree DJ, Pomeranz G, Kolatsi-Joannou M, Rottner AK, Pacheco S, Moulding DA, Wolf A, Kupatt C, Peppiatt-Wildman C, Papakrivopoulou E, Riley PR, Long DA, Vasilopoulou E. Systemic gene therapy with thymosin β4 alleviates glomerular injury in mice. Sci Rep 2022; 12:12172. [PMID: 35842494 PMCID: PMC9288454 DOI: 10.1038/s41598-022-16287-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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 07/07/2022] [Indexed: 11/17/2022] Open
Abstract
Plasma ultrafiltration in the kidney occurs across glomerular capillaries, which are surrounded by epithelial cells called podocytes. Podocytes have a unique shape maintained by a complex cytoskeleton, which becomes disrupted in glomerular disease resulting in defective filtration and albuminuria. Lack of endogenous thymosin β4 (TB4), an actin sequestering peptide, exacerbates glomerular injury and disrupts the organisation of the podocyte actin cytoskeleton, however, the potential of exogenous TB4 therapy to improve podocyte injury is unknown. Here, we have used Adriamycin (ADR), a toxin which injures podocytes and damages the glomerular filtration barrier leading to albuminuria in mice. Through interrogating single-cell RNA-sequencing data of isolated glomeruli we demonstrate that ADR injury results in reduced levels of podocyte TB4. Administration of an adeno-associated viral vector encoding TB4 increased the circulating level of TB4 and prevented ADR-induced podocyte loss and albuminuria. ADR injury was associated with disorganisation of the podocyte actin cytoskeleton in vitro, which was ameliorated by treatment with exogenous TB4. Collectively, we propose that systemic gene therapy with TB4 prevents podocyte injury and maintains glomerular filtration via protection of the podocyte cytoskeleton thus presenting a novel treatment strategy for glomerular disease.
Collapse
Affiliation(s)
- William J Mason
- Division of Natural Sciences, Medway School of Pharmacy, University of Kent, Chatham, Kent, UK.,Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Daniyal J Jafree
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK.,UCL MB/PhD Programme, Faculty of Medical Science, University College London, London, UK
| | - Gideon Pomeranz
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Maria Kolatsi-Joannou
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Antje K Rottner
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Sabrina Pacheco
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Dale A Moulding
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Anja Wolf
- Medizinische Klinik und Poliklinik I, University Clinic Rechts der Isar, TUM Munich, Munich, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Christian Kupatt
- Medizinische Klinik und Poliklinik I, University Clinic Rechts der Isar, TUM Munich, Munich, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | | | - Eugenia Papakrivopoulou
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK.,Department of Internal Medicine and Nephrology, Clinique Saint Jean, Brussels, Belgium
| | - Paul R Riley
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - David A Long
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Elisavet Vasilopoulou
- Division of Natural Sciences, Medway School of Pharmacy, University of Kent, Chatham, Kent, UK. .,Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK. .,Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London, NW1 0TU, UK.
| |
Collapse
|
3
|
Bryant D, Pauzuolyte V, Ingham NJ, Patel A, Pagarkar W, Anderson LA, Smith KE, Moulding DA, Leong YC, Jafree DJ, Long DA, Al-Yassin A, Steel KP, Jagger DJ, Forge A, Berger W, Sowden JC, Bitner-Glindzicz M. The timing of auditory sensory deficits in Norrie disease has implications for therapeutic intervention. JCI Insight 2022; 7:148586. [PMID: 35132964 PMCID: PMC8855802 DOI: 10.1172/jci.insight.148586] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 12/10/2021] [Indexed: 11/29/2022] Open
Abstract
Norrie disease is caused by mutation of the NDP gene, presenting as congenital blindness followed by later onset of hearing loss. Protecting patients from hearing loss is critical for maintaining their quality of life. This study aimed to understand the onset of pathology in cochlear structure and function. By investigating patients and juvenile Ndp-mutant mice, we elucidated the sequence of onset of physiological changes (in auditory brainstem responses, distortion product otoacoustic emissions, endocochlear potential, blood-labyrinth barrier integrity) and determined the cellular, histological, and ultrastructural events leading to hearing loss. We found that cochlear vascular pathology occurs earlier than previously reported and precedes sensorineural hearing loss. The work defines a disease mechanism whereby early malformation of the cochlear microvasculature precedes loss of vessel integrity and decline of endocochlear potential, leading to hearing loss and hair cell death while sparing spiral ganglion cells. This provides essential information on events defining the optimal therapeutic window and indicates that early intervention is needed. In an era of advancing gene therapy and small-molecule technologies, this study establishes Ndp-mutant mice as a platform to test such interventions and has important implications for understanding the progression of hearing loss in Norrie disease.
Collapse
Affiliation(s)
- Dale Bryant
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Valda Pauzuolyte
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Neil J Ingham
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Aara Patel
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Waheeda Pagarkar
- Great Ormond Street Hospital, Great Ormond Street, London, United Kingdom
| | - Lucy A Anderson
- UCL Ear Institute, University College London, London, United Kingdom
| | - Katie E Smith
- UCL Ear Institute, University College London, London, United Kingdom
| | - Dale A Moulding
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Yeh C Leong
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Daniyal J Jafree
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom.,UCL MB/PhD Programme, Faculty of Medical Sciences, University College London, London, United Kingdom
| | - David A Long
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Amina Al-Yassin
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Karen P Steel
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Daniel J Jagger
- UCL Ear Institute, University College London, London, United Kingdom
| | - Andrew Forge
- UCL Ear Institute, University College London, London, United Kingdom
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zürich, Schlieren, Switzerland.,Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Jane C Sowden
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - Maria Bitner-Glindzicz
- UCL Great Ormond Street Institute of Child Health, University College London, and NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| |
Collapse
|
4
|
Li YF, Scerif F, Picker SR, Stone TJ, Pickles JC, Moulding DA, Avery A, Virasami A, Fairchild AR, Tisdall M, Harkness W, Cross JH, Hargrave D, Guillemot F, Paine SM, Yasin SA, Jacques TS. Identifying cellular signalling molecules in developmental disorders of the brain: Evidence from focal cortical dysplasia and tuberous sclerosis. Neuropathol Appl Neurobiol 2021; 47:781-795. [PMID: 33797808 DOI: 10.1111/nan.12715] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/18/2021] [Accepted: 03/22/2021] [Indexed: 12/24/2022]
Abstract
AIMS We understand little of the pathogenesis of developmental cortical lesions, because we understand little of the diversity of the cell types that contribute to the diseases or how those cells interact. We tested the hypothesis that cellular diversity and cell-cell interactions play an important role in these disorders by investigating the signalling molecules in the commonest cortical malformations that lead to childhood epilepsy, focal cortical dysplasia (FCD) and tuberous sclerosis (TS). METHODS Transcriptional profiling clustered cases into molecularly distinct groups. Using gene expression data, we identified the secretory signalling molecules in FCD/TS and characterised the cell types expressing these molecules. We developed a functional model using organotypic cultures. RESULTS We identified 113 up-regulated secretory molecules in FCDIIB/TS. The top 12 differentially expressed genes (DEGs) were validated by immunohistochemistry. This highlighted two molecules, Chitinase 3-like protein 1 (CHI3L1) and C-C motif chemokine ligand 2 (CCL2) (MCP1) that were expressed in a unique population of small cells in close proximity to balloon cells (BC). We then characterised these cells and developed a functional model in organotypic slice cultures. We found that the number of CHI3L1 and CCL2 expressing cells decreased following inhibition of mTOR, the main aberrant signalling pathway in TS and FCD. CONCLUSIONS Our findings highlight previously uncharacterised small cell populations in FCD and TS which express specific signalling molecules. These findings indicate a new level of diversity and cellular interactions in cortical malformations and provide a generalisable approach to understanding cell-cell interactions and cellular heterogeneity in developmental neuropathology.
Collapse
Affiliation(s)
- Yao-Feng Li
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK.,Pathology Department, Tri-Service General Hospital & National Defence Medical Centre, Taipei, Taiwan
| | - Fatma Scerif
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Simon R Picker
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Thomas J Stone
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Jessica C Pickles
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Dale A Moulding
- ICH GOS Imaging Facility, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Aimee Avery
- Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Alex Virasami
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Amy R Fairchild
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Martin Tisdall
- Neurosurgery, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - William Harkness
- Neurosurgery, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - J Helen Cross
- Neurosciences Unit, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Darren Hargrave
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Neuro-Oncology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Francois Guillemot
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, London, UK
| | - Simon M Paine
- Department of Neuropathology, Queens Medical Centre, Nottingham University NHS Trust, Nottingham, UK
| | - Shireena A Yasin
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Thomas S Jacques
- Developmental Biology and Cancer Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.,Departments of Histopathology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
5
|
Lee KKL, Peskett E, Quinn CM, Aiello R, Adeeva L, Moulding DA, Stanier P, Pauws E. Overexpression of Fgfr2c causes craniofacial bone hypoplasia and ameliorates craniosynostosis in the Crouzon mouse. Dis Model Mech 2018; 11:dmm035311. [PMID: 30266836 PMCID: PMC6262810 DOI: 10.1242/dmm.035311] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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: 05/04/2018] [Accepted: 09/19/2018] [Indexed: 01/09/2023] Open
Abstract
FGFR2c regulates many aspects of craniofacial and skeletal development. Mutations in the FGFR2 gene are causative of multiple forms of syndromic craniosynostosis, including Crouzon syndrome. Paradoxically, mouse studies have shown that the activation (Fgfr2cC342Y; a mouse model for human Crouzon syndrome), as well as the removal (Fgfr2cnull), of the FGFR2c isoform can drive suture abolishment. This study aims to address the downstream effects of pathogenic FGFR2c signalling by studying the effects of Fgfr2c overexpression. Conditional overexpression of Fgfr2c (R26RFgfr2c;βact) results in craniofacial hypoplasia as well as microtia and cleft palate. Contrary to Fgfr2cnull and Fgfr2cC342Y, Fgfr2c overexpression is insufficient to drive onset of craniosynostosis. Examination of the MAPK/ERK pathway in the embryonic sutures of Fgfr2cC342Y and R26RFgfr2c;βact mice reveals that both mutants have increased pERK expression. The contrasting phenotypes between Fgfr2cC342Y and R26RFgfr2c;βact mice prompted us to assess the impact of the Fgfr2c overexpression allele on the Crouzon mouse (Fgfr2cC342Y), in particular its effects on the coronal suture. Our results demonstrate that Fgfr2c overexpression is sufficient to partially rescue craniosynostosis through increased proliferation and reduced osteogenic activity in E18.5 Fgfr2cC342Y embryos. This study demonstrates the intricate balance of FGF signalling required for correct calvarial bone and suture morphogenesis, and that increasing the expression of the wild-type FGFR2c isoform could be a way to prevent or delay craniosynostosis progression.
Collapse
Affiliation(s)
- Kevin K L Lee
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Emma Peskett
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Charlotte M Quinn
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Rosanna Aiello
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Liliya Adeeva
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Dale A Moulding
- ICH GOSH Light Microscopy Core Facility, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Philip Stanier
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Erwin Pauws
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| |
Collapse
|
6
|
Buonocore F, Kühnen P, Suntharalingham JP, Del Valle I, Digweed M, Stachelscheid H, Khajavi N, Didi M, Brady AF, Blankenstein O, Procter AM, Dimitri P, Wales JK, Ghirri P, Knöbl D, Strahm B, Erlacher M, Wlodarski MW, Chen W, Kokai GK, Anderson G, Morrogh D, Moulding DA, McKee SA, Niemeyer CM, Grüters A, Achermann JC. Somatic mutations and progressive monosomy modify SAMD9-related phenotypes in humans. J Clin Invest 2017; 127:1700-1713. [PMID: 28346228 PMCID: PMC5409795 DOI: 10.1172/jci91913] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [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: 11/28/2016] [Accepted: 01/26/2017] [Indexed: 12/24/2022] Open
Abstract
It is well established that somatic genomic changes can influence phenotypes in cancer, but the role of adaptive changes in developmental disorders is less well understood. Here we have used next-generation sequencing approaches to identify de novo heterozygous mutations in sterile α motif domain-containing protein 9 (SAMD9, located on chromosome 7q21.2) in 8 children with a multisystem disorder termed MIRAGE syndrome that is characterized by intrauterine growth restriction (IUGR) with gonadal, adrenal, and bone marrow failure, predisposition to infections, and high mortality. These mutations result in gain of function of the growth repressor product SAMD9. Progressive loss of mutated SAMD9 through the development of monosomy 7 (-7), deletions of 7q (7q-), and secondary somatic loss-of-function (nonsense and frameshift) mutations in SAMD9 rescued the growth-restricting effects of mutant SAMD9 proteins in bone marrow and was associated with increased length of survival. However, 2 patients with -7 and 7q- developed myelodysplastic syndrome, most likely due to haploinsufficiency of related 7q21.2 genes. Taken together, these findings provide strong evidence that progressive somatic changes can occur in specific tissues and can subsequently modify disease phenotype and influence survival. Such tissue-specific adaptability may be a more common mechanism modifying the expression of human genetic conditions than is currently recognized.
Collapse
Affiliation(s)
- Federica Buonocore
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Peter Kühnen
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - Jenifer P. Suntharalingham
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Ignacio Del Valle
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Martin Digweed
- Department of Human and Medical Genetics, Charité, Berlin, Germany
| | - Harald Stachelscheid
- Berlin Institute of Health, Berlin, Germany, and Berlin-Brandenburg Centrum for Regenerative Therapies, Charité, Berlin, Germany
| | - Noushafarin Khajavi
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - Mohammed Didi
- Department of Paediatric Endocrinology, Alder Hey Children’s NHS Foundation Trust, Liverpool, United Kingdom
| | - Angela F. Brady
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, United Kingdom
| | - Oliver Blankenstein
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - Annie M. Procter
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Paul Dimitri
- Academic Unit of Child Health, University of Sheffield, Sheffield, United Kingdom
| | - Jerry K.H. Wales
- Department of Endocrinology, Children’s Health Queensland Clinical Unit, University of Queensland, Brisbane, Australia
| | - Paolo Ghirri
- Department of Neonatology, University of Pisa, Pisa, Italy
| | | | - Brigitte Strahm
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Miriam Erlacher
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) and German Research Center (DKFZ), Heidelberg, Germany
| | - Marcin W. Wlodarski
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) and German Research Center (DKFZ), Heidelberg, Germany
| | - Wei Chen
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - George K. Kokai
- Department of Paediatric Histopathology, Alder Hey Children’s NHS Foundation Trust, Liverpool, United Kingdom
| | - Glenn Anderson
- Histopathology Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Deborah Morrogh
- North East Thames Regional Genetics Laboratory Service, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Dale A. Moulding
- Developmental Biology and Cancer, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Shane A. McKee
- Department of Genetic Medicine, Belfast City Hospital, Belfast, United Kingdom
| | - Charlotte M. Niemeyer
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK) and German Research Center (DKFZ), Heidelberg, Germany
| | - Annette Grüters
- Institute of Experimental Pediatric Endocrinology and Department of Pediatric Endocrinology, Charité, Berlin, Germany
| | - John C. Achermann
- Genetics and Genomic Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| |
Collapse
|
7
|
Abstract
The importance of the cytoskeleton in mounting a successful immune response is evident from the wide range of defects that occur in actin-related primary immunodeficiencies (PIDs). Studies of these PIDs have revealed a pivotal role for the actin cytoskeleton in almost all stages of immune system function, from hematopoiesis and immune cell development, through to recruitment, migration, intercellular and intracellular signaling, and activation of both innate and adaptive immune responses. The major focus of this review is the immune defects that result from mutations in the Wiskott-Aldrich syndrome gene (WAS), which have a broad impact on many different processes and give rise to clinically heterogeneous immunodeficiencies. We also discuss other related genetic defects and the possibility of identifying new genetic causes of cytoskeletal immunodeficiency.
Collapse
Affiliation(s)
- Dale A Moulding
- Molecular Immunology Unit, Center for Immunodeficiency, Institute of Child Health, University College London, London, UK
| | | | | | | |
Collapse
|
8
|
Moeendarbary E, Valon L, Fritzsche M, Harris AR, Moulding DA, Thrasher AJ, Stride E, Mahadevan L, Charras GT. The cytoplasm of living cells behaves as a poroelastic material. Nat Mater 2013; 12:253-61. [PMID: 23291707 PMCID: PMC3925878 DOI: 10.1038/nmat3517] [Citation(s) in RCA: 341] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 12/05/2012] [Indexed: 05/20/2023]
Abstract
The cytoplasm is the largest part of the cell by volume and hence its rheology sets the rate at which cellular shape changes can occur. Recent experimental evidence suggests that cytoplasmic rheology can be described by a poroelastic model, in which the cytoplasm is treated as a biphasic material consisting of a porous elastic solid meshwork (cytoskeleton, organelles, macromolecules) bathed in an interstitial fluid (cytosol). In this picture, the rate of cellular deformation is limited by the rate at which intracellular water can redistribute within the cytoplasm. However, direct supporting evidence for the model is lacking. Here we directly validate the poroelastic model to explain cellular rheology at short timescales using microindentation tests in conjunction with mechanical, chemical and genetic treatments. Our results show that water redistribution through the solid phase of the cytoplasm (cytoskeleton and macromolecular crowders) plays a fundamental role in setting cellular rheology at short timescales.
Collapse
Affiliation(s)
- Emad Moeendarbary
- London Centre for Nanotechnology, University College London, London, WC1E 6JF, UK
- Department of Mechanical Engineering, University College London, London, WC1E 6JF, UK
| | - Léo Valon
- London Centre for Nanotechnology, University College London, London, WC1E 6JF, UK
- Department of Physics, Ecole Normale Superieure, Paris, France
| | - Marco Fritzsche
- London Centre for Nanotechnology, University College London, London, WC1E 6JF, UK
- Department of Physics and Astronomy, University College London, London, WC1E 6JF, UK
| | - Andrew R. Harris
- London Centre for Nanotechnology, University College London, London, WC1E 6JF, UK
- Department of Physics and Astronomy, University College London, London, WC1E 6JF, UK
| | - Dale A. Moulding
- Molecular Immunology Unit, Institute of Child Health, University College London, London, WC1E 6JF, UK
| | - Adrian J. Thrasher
- Molecular Immunology Unit, Institute of Child Health, University College London, London, WC1E 6JF, UK
| | - Eleanor Stride
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - L. Mahadevan
- School of Engineering and Applied Sciences, Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Guillaume T. Charras
- London Centre for Nanotechnology, University College London, London, WC1E 6JF, UK
- Department of Cell and Developmental Biology, University College London, London, WC1E 6JF, UK
| |
Collapse
|
9
|
Moulding DA, Blundell MP, Spiller DG, White MR, Cory GO, Calle Y, Kempski H, Sinclair J, Ancliff PJ, Kinnon C, Jones GE, Thrasher AJ. Unregulated actin polymerization by WASp causes defects of mitosis and cytokinesis in X-linked neutropenia. J Biophys Biochem Cytol 2007. [DOI: 10.1083/jcb1786oia11] [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: 11/22/2022] Open
|
10
|
Moulding DA, Blundell MP, Spiller DG, White MRH, Cory GO, Calle Y, Kempski H, Sinclair J, Ancliff PJ, Kinnon C, Jones GE, Thrasher AJ. Unregulated actin polymerization by WASp causes defects of mitosis and cytokinesis in X-linked neutropenia. ACTA ACUST UNITED AC 2007; 204:2213-24. [PMID: 17724125 PMCID: PMC2118706 DOI: 10.1084/jem.20062324] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [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] [Indexed: 12/19/2022]
Abstract
Specific mutations in the human gene encoding the Wiskott-Aldrich syndrome protein (WASp) that compromise normal auto-inhibition of WASp result in unregulated activation of the actin-related protein 2/3 complex and increased actin polymerizing activity. These activating mutations are associated with an X-linked form of neutropenia with an intrinsic failure of myelopoiesis and an increase in the incidence of cytogenetic abnormalities. To study the underlying mechanisms, active mutant WASp(I294T) was expressed by gene transfer. This caused enhanced and delocalized actin polymerization throughout the cell, decreased proliferation, and increased apoptosis. Cells became binucleated, suggesting a failure of cytokinesis, and micronuclei were formed, indicative of genomic instability. Live cell imaging demonstrated a delay in mitosis from prometaphase to anaphase and confirmed that multinucleation was a result of aborted cytokinesis. During mitosis, filamentous actin was abnormally localized around the spindle and chromosomes throughout their alignment and separation, and it accumulated within the cleavage furrow around the spindle midzone. These findings reveal a novel mechanism for inhibition of myelopoiesis through defective mitosis and cytokinesis due to hyperactivation and mislocalization of actin polymerization.
Collapse
Affiliation(s)
- Dale A Moulding
- Wolfson Centre for Gene Therapy of Childhood Disease, UCL Institute of Child Health, University College London, London, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Derouet M, Thomas L, Moulding DA, Akgul C, Cross A, Moots RJ, Edwards SW. Sodium Salicylate Promotes Neutrophil Apoptosis by Stimulating Caspase-Dependent Turnover of Mcl-1. J Immunol 2006; 176:957-65. [PMID: 16393981 DOI: 10.4049/jimmunol.176.2.957] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Mcl-1 is an antiapoptotic member of the Bcl-2 family of proteins that plays a central role in cell survival of neutrophils and other cells. The protein is unusual among family members in that it has a very short half-life of 2-3 h. In this report, we show that sodium salicylate (at 10 mM) greatly enhances the rate at which neutrophils undergo apoptosis and, in parallel, greatly accelerates the turnover rate of Mcl-1, decreasing its half-life to only 90 min. Whereas constitutive and GM-CSF-modified Mcl-1 turnover is regulated by the proteasome, the accelerated sodium salicylate-induced Mcl-1 turnover is mediated largely via caspases. Sodium salicylate resulted in rapid activation of caspase-3, -8, -9, and -10, and salicylate-accelerated Mcl-1 turnover was partly blocked by caspase inhibitors. Sodium salicylate also induced dramatic changes in the activities of members of the MAPK family implicated in Mcl-1 turnover and apoptosis. For example, sodium salicylate blocked GM-CSF-stimulated Erk and Akt activation, but resulted in rapid and sustained activation of p38-MAPK, an event mimicked by okadaic acid that also accelerates Mcl-1 turnover and neutrophil apoptosis. These data thus shed important new insights into the dynamic and highly regulated control of neutrophil apoptosis that is effected by modification in the rate of Mcl-1 turnover.
Collapse
Affiliation(s)
- Mathieu Derouet
- School of Biological Sciences, University of Liverpool, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
12
|
Horton SJ, Grier DG, McGonigle GJ, Thompson A, Morrow M, De Silva I, Moulding DA, Kioussis D, Lappin TRJ, Brady HJM, Williams O. Continuous MLL-ENL expression is necessary to establish a "Hox Code" and maintain immortalization of hematopoietic progenitor cells. Cancer Res 2005; 65:9245-52. [PMID: 16230385 DOI: 10.1158/0008-5472.can-05-1691] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [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] [Indexed: 11/16/2022]
Abstract
The t[(11;19)(p22;q23)] translocation, which gives rise to the MLL-ENL fusion protein, is commonly found in infant acute leukemias of both the myeloid and lymphoid lineage. To investigate the molecular mechanism of immortalization by MLL-ENL we established a Tet-regulatable system of MLL-ENL expression in primary hematopoietic progenitor cells. Immortalized myeloid cell lines were generated, which are dependent on continued MLL-ENL expression for their survival and proliferation. These cells either terminally differentiate or die when MLL-ENL expression is turned off with doxycycline. The expression profile of all 39 murine Hox genes was analyzed in these cells by real-time quantitative PCR. This analysis showed that loss of MLL-ENL was accompanied by a reduction in the expression of multiple Hoxa genes. By comparing these changes with Hox gene expression in cells induced to differentiate with granulocyte colony-stimulating factor, we show for the first time that reduced Hox gene expression is specific to loss of MLL-ENL and is not a consequence of differentiation. Our data also suggest that the Hox cofactor Meis-2 can substitute for Meis-1 function. Thus, MLL-ENL is required to initiate and maintain immortalization of myeloid progenitors and may contribute to leukemogenesis by aberrantly sustaining the expression of a "Hox code" consisting of Hoxa4 to Hoxa11.
Collapse
Affiliation(s)
- Sarah J Horton
- Molecular Haematology and Cancer Biology Unit, Institute of Child Health, University College London
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
Apoptosis is a morphologically distinct form of cell death. It is executed and regulated by several groups of proteins. Bcl-2 family proteins are the main regulators of the apoptotic process acting either to inhibit or promote it. More than 20 members of the family have been identified so far and most have two or more isoforms. Alternative splicing is one of the major mechanisms providing proteomic complexity and functional diversification of the Bcl-2 family proteins. Pro- and anti-apoptotic Bcl-2 family members should function in harmony for the regulation of the apoptosis machinery, and their relative levels are critical for cell fate. Any mechanism breaking down this harmony by changing the relative levels of these antagonistic proteins could contribute to many diseases, including cancer and neurodegenerative disorders. Recent studies have shown that manipulation of the alternative splicing mechanisms could provide an opportunity to restore the proper balance of these regulator proteins. This review summarises current knowledge on the alternative splicing products of Bcl-2-related genes and modulation of splicing mechanisms as a potential therapeutic approach.
Collapse
Affiliation(s)
- C Akgul
- Faculty of Arts and Sciences, Department of Chemistry, Biochemistry Research Group, Canakkale Onsekiz Mart University, Terzioglu Campus, 17100, Canakkale, Turkey.
| | | | | |
Collapse
|
14
|
Affiliation(s)
- Steven W Edwards
- School of Biological Sciences, University of Liverpool, Liverpool, UK.
| | | | | | | |
Collapse
|
15
|
Fossati G, Moulding DA, Spiller DG, Moots RJ, White MRH, Edwards SW. The mitochondrial network of human neutrophils: role in chemotaxis, phagocytosis, respiratory burst activation, and commitment to apoptosis. J Immunol 2003; 170:1964-72. [PMID: 12574365 DOI: 10.4049/jimmunol.170.4.1964] [Citation(s) in RCA: 252] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It is commonly assumed that human neutrophils possess few, if any, functional mitochondria and that they do not depend on these organelles for cell function. We have used the fluorescent mitochondrial indicators, JC-1, MitoTracker Red, and dihydrorhodamine 123 to show that live neutrophils possess a complex mitochondrial network that extends through the cytoplasm. The membrane potential of these mitochondria was rapidly (within 2 min) disrupted by the addition of FCCP (IC(50) = 20 nM), but not by the Fo-ATPase inhibitor, oligomycin (at up to 7 microg/ml). However, inhibition of mitochondrial function with both agents resulted in cell shape changes. Neither activation of the respiratory burst nor phagocytosis of either latex particles or serum-opsonized Staphylococcus aureus was affected by the addition of FCCP or oligomycin. However, FCCP inhibited chemotaxis at concentrations that paralleled disruption of mitochondrial membrane potential. Furthermore, prolonged (2-h) incubation with oligomycin resulted in an impaired ability to activate a respiratory burst and also inhibited chemotaxis. These observations indicate that intact mitochondrial function is required to sustain some neutrophil functions, but not for the rapid initiation of the respiratory burst or phagocytosis. Loss of mitochondrial membrane potential was a very early marker for commitment of neutrophils into apoptosis and preceded the appearance of phosphatidylserine on the cell surface. However, inhibition of mitochondrial function did not accelerate the rate of neutrophil apoptosis. These data shed important insights into the hitherto unrecognized importance of mitochondria in the function of neutrophils during infection and inflammation.
Collapse
Affiliation(s)
- Gianluca Fossati
- Department of Medicine, School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, UK
| | | | | | | | | | | |
Collapse
|
16
|
Moulding DA, Akgul C, Derouet M, White MR, Edwards SW. BCL-2 family expression in human neutrophils during delayed and accelerated apoptosis. J Leukoc Biol 2001; 70:783-92. [PMID: 11698499] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
The human neutrophil spontaneously undergoes apoptosis, but this type of cell death can be delayed or accelerated by a wide variety of agents. There are wide discrepancies in the literature regarding the expression of the Bcl-2 family of proteins in human neutrophils. Here, we show that A1, Mcl-1, Bcl-X(L), and Bad are major transcripts in human neutrophils and that levels of these transcripts are cytokine regulated. However, no Bcl-X(L) protein was detected in Western blots. Protein levels for the proapoptotic proteins Bad, Bax, Bak, and Bik remained constant during culture, despite changes in the levels of mRNA for these gene products. These proapoptotic proteins were extremely stable, having very long half-lives. In contrast, A1 and Mcl-1 transcripts were extremely unstable (with approximately 3-h half-lives), and Mcl-1 protein was also subject to rapid turnover. These results indicate that neutrophil survival is regulated by the inducible expression of the short-lived Mcl-1 and possibly the A1 gene products. In the absence of their continued expression, these prosurvival gene products are rapidly turned over, and then the activity of the stable death proteins predominates and promotes apoptosis.
Collapse
Affiliation(s)
- D A Moulding
- The University of Liverpool, School of Biological Sciences, Life Sciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom
| | | | | | | | | |
Collapse
|
17
|
Moulding DA, Akgul C, Derouet M, White MRH, Edwards SW. BCL‐2 family expression in human neutrophils during delayed and accelerated apoptosis. J Leukoc Biol 2001. [DOI: 10.1189/jlb.70.5.783] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Dale A. Moulding
- The University of Liverpool, School of Biological Sciences, Life Sciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom
| | - Cahit Akgul
- The University of Liverpool, School of Biological Sciences, Life Sciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom
| | - Mathieu Derouet
- The University of Liverpool, School of Biological Sciences, Life Sciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom
| | - Michael R. H. White
- The University of Liverpool, School of Biological Sciences, Life Sciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom
| | - Steven W. Edwards
- The University of Liverpool, School of Biological Sciences, Life Sciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom
| |
Collapse
|
18
|
Abstract
Human neutrophils constitutively undergo apoptosis and this process is critical for the resolution of inflammation. Whilst neutrophil apoptosis can be modulated by a wide variety of agents including GM-CSF, LPS and TNF-alpha, the molecular mechanisms underlying neutrophil death and survival remain largely undefined. Recent studies have shown the involvement of members of the Bcl-2 protein family (especially Mcl-1 and A1) and caspases in the regulation and execution of neutrophil apoptosis. Cell surface receptors and protein kinases, particularly mitogen-activated protein kinases, also play critical roles in transducing the signals that result in neutrophil apoptosis or extended survival. This review summarises current knowledge on the molecular mechanisms and components of neutrophil apoptosis.
Collapse
Affiliation(s)
- C Akgul
- Life Sciences Building, School of Biological Sciences, University of Liverpool, L69 7ZB, Liverpool, UK
| | | | | |
Collapse
|
19
|
Moulding DA, Giles RV, Spiller DG, White MR, Tidd DM, Edwards SW. Apoptosis is rapidly triggered by antisense depletion of MCL-1 in differentiating U937 cells. Blood 2000; 96:1756-63. [PMID: 10961874] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Mcl-1 is a member of the Bcl-2 protein family, which has been shown to delay apoptosis in transfection and/or overexpression experiments. As yet no gene knockout mice have been engineered, and so there is little evidence to show that loss of Mcl-1 expression is sufficient to trigger apoptosis. U937 cells constitutively express the antiapoptotic protein Bcl-2; but during differentiation, in response to the phorbol ester PMA (phorbol 12 beta-myristate 13 alpha-acetate), Mcl-1 is transiently induced. The purpose of this investigation was to determine the functional role played by Mcl-1 in this differentiation program. Mcl-1 expression was specifically disrupted by chimeric methylphosphonate/phosphodiester antisense oligodeoxynucleotides to just 5% of control levels. The depletion of Mcl-1 messenger RNA (mRNA) and protein was both rapid and specific, as indicated by the use of control oligodeoxynucleotides and analysis of the expression of other BCL2 family members and PMA-induced tumor necrosis factor-alpha (TNF-alpha). Specific depletion of Mcl-1 mRNA and protein, in the absence of changes in cellular levels of Bcl-2, results in a rapid entry into apoptosis. Levels of the proapoptotic protein Bax remained unchanged during differentiation, while Bak expression doubled within 24 hours. Apoptosis was detected within 4 hours of Mcl-1 antisense treatment by a variety of parameters including a novel live cell imaging technique allowing correlation of antisense treatment and apoptosis in individual cells. The induction of Mcl-1 is required to prevent apoptosis during differentiation of U937 cells, and the constitutive expression of Bcl-2 is unable to compensate for the loss of Mcl-1. (Blood. 2000;96:1756-1763)
Collapse
Affiliation(s)
- D A Moulding
- School of Biological Sciences and the Department of Haematology, University of Liverpool, Liverpool, England.
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
Mcl-1 is an anti-apoptotic member of the Bcl-2 family of proteins. We have expressed full length and mutated GFP:Mcl-1 fusion proteins to define structural motifs that control protein localisation and stability. When expressed in U-937 cells, full length Mcl-1 locates primarily within mitochondria and its half-life was approximately 3 h, which was identical to the native, endogenously expressed protein. When the terminal 20 amino acids from the C-terminus of the protein were detected, the protein was diffused in the cytoplasm, but its stability was unaffected. This confirms that this region is responsible for efficient targeting to mitochondria. Surprisingly, deletion of 104 amino acids (residues 79-183) that contain putative PEST sequences and other stability regulating motifs, did not affect protein stability.
Collapse
Affiliation(s)
- C Akgul
- School of Biological Sciences, Life Sciences Building, University of Liverpool, L69 7ZB, Liverpool, UK
| | | | | | | |
Collapse
|
21
|
Moulding DA, Hart CA, Edwards SW. Regulation of neutrophil FcgammaRIIIb (CD16) surface expression following delayed apoptosis in response to GM-CSF and sodium butyrate. J Leukoc Biol 1999; 65:875-82. [PMID: 10380913 DOI: 10.1002/jlb.65.6.875] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [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: 11/10/2022] Open
Abstract
When neutrophils undergo apoptosis, they lose expression of the surface receptor CD16 (FcgammaRIIIb). Thus levels of surface CD16 are good indicators of apoptotic or non-apoptotic neutrophils. Shedding of CD16 occurs via the activity of a metalloproteinase that cleaves the receptor from the plasma membrane. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and sodium butyrate both stimulate neutrophil gene expression, protect these cells from apoptosis, and maintain expression of surface CD16. In this report we have investigated whether these agents maintain surface expression of CD16 via (1) decreased shedding (2) increased mobilization of the internal pool of pre-formed CD16, or (3) via de novo biosynthesis of new receptor molecules. Although GM-CSF and sodium butyrate both preserved surface expression of CD16, GM-CSF actually accelerated the rate of shedding of this receptor. Maintenance of surface levels was achieved by substantial mobilization of the internal pool of CD16. Sodium butyrate, on the other hand, maintained surface expression without extensive store depletion via a mechanism that appeared to involve a decreased rate of shedding. In these experiments we could find no evidence for de novo biosynthesis of CD16 stimulated by either GM-CSF or sodium butyrate. These experiments indicate that multiple mechanisms exist for the maintenance of surface CD16 during rescue of neutrophils from apoptosis by different agents.
Collapse
Affiliation(s)
- D A Moulding
- School of Biological Sciences, University of Liverpool, United Kingdom
| | | | | |
Collapse
|
22
|
Abstract
Staphylococcal enterotoxins have marked effects on the properties of T cells and monocytes and have recently been reported to affect neutrophil function. In this study, we investigated the abilities of staphylococcal enterotoxins A and B and toxic shock syndrome toxin 1 to affect respiratory burst activity and to delay apoptosis in human neutrophils. When cultures containing approximately 97% neutrophils were tested, the toxins all delayed neutrophil apoptosis in a dose-dependent manner and induced the expression of FcgammaRI on the neutrophil cell surface. These effects on apoptosis and expression of FcgammaRI were largely abrogated by the addition of a neutralizing anti-gamma interferon antibody. Similarly, the effects of these toxins on phorbol ester-induced chemiluminescence were decreased after neutralization of gamma interferon. These effects on neutrophil function were mimicked by the addition of conditioned medium from peripheral blood mononuclear cells incubated with the toxins, and again, neutralizing anti-gamma interferon antibodies largely negated the effects. However, when highly purified neutrophils prepared by immunodepletion of T cells and major histocompatibility complex class II-expressing cells were analyzed, the toxins were without effect on apoptosis and FcgammaRI expression, but granulocyte-macrophage colony-stimulating factor and gamma interferon could still delay apoptosis. These data indicate that these toxins have no direct effect on neutrophil apoptosis but can act indirectly via the production of T-cell-derived and monocyte-derived cytokines. It is noteworthy that such effects are detected in neutrophil suspensions containing only 3% contamination with T cells and other mononuclear cells.
Collapse
Affiliation(s)
- D A Moulding
- School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | | | | | | |
Collapse
|
23
|
Moulding DA, Quayle JA, Hart CA, Edwards SW. Mcl-1 expression in human neutrophils: regulation by cytokines and correlation with cell survival. Blood 1998; 92:2495-502. [PMID: 9746790] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Human neutrophils possess a very short half-life because they constitutively undergo apoptosis. Cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), and other agents can rescue neutrophils from apoptosis but the molecular mechanisms involved in this rescue are undefined. Here, we show by Western blotting that human neutrophils do not express Bcl-2 or Bcl-X but constitutively express Bax. However, cellular levels of these proteins are unaffected by agents which either accelerate or delay neutrophil apoptosis. In contrast, neutrophils express the antiapoptotic protein Mcl-1 and levels of this protein correlate with neutrophil survival. Thus, cellular levels of Mcl-1 decline as neutrophils undergo apoptosis and are enhanced by agents (eg, GM-CSF, interleukin-1beta, sodium butyrate, and lipopolysaccharide) that promote neutrophil survival. Neutrophils only possess few, small mitochondria, and much of the Mcl-1 protein seems to be located in nuclear fractions. These observations provide the first evidence implicating a Bcl-2 family member in the regulation of neutrophil survival. Moreover, this work also provides a potential mechanism whereby cytokine-regulated gene expression regulates the functional lifespan of neutrophils and hence their ability to function for extended time periods during acute inflammation.
Collapse
Affiliation(s)
- D A Moulding
- School of Biological Sciences, Life Sciences Building; and the Department of Medical Microbiology, University of Liverpool, Liverpool, UK
| | | | | | | |
Collapse
|
24
|
Fossati G, Mazzucchelli I, Gritti D, Ricevuti G, Edwards SW, Moulding DA, Rossi ML. In vitro effects of GM-CSF on mature peripheral blood neutrophils. Int J Mol Med 1998; 1:943-51. [PMID: 9852629 DOI: 10.3892/ijmm.1.6.943] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 11/05/2022] Open
Abstract
GM-CSF can play a crucial role in regulating the neutrophil-mediated inflammatory response. This growth factor is a proliferative stimulus for bone marrow neutrophil stem cell precursors and has at least 3 important roles in regulating neutrophil-mediated immunity: a) a direct effect on the proliferation and development of neutrophil progenitors; b) synergistic activity with other haemopoietic growth factors; c) stimulation of the functional activity of mature neutrophils. The production of GM-CSF may be triggered directly by exogenous factors such as antigens and endotoxins, or indirectly through the release of cytokines by a variety of cells including lymphocytes, activated macrophages and endothelial cells exposed to products of mononuclear phagocytes. Such production of GM-CSF may serve to quickly release mature neutrophils from the bone marrow in response to infections. Moreover, enhancement of the function of mature neutrophils may also augment their ability to migrate to infective sites and then phagocytose and kill pathogens. Increased expression of CD11b/CD18 may play a fundamental part in this mechanism because this receptor is essential for the adhesion of neutrophils to the endothelium. Both phagocytosis and oxidative burst activity increase as a result of the action of GM-CSF and the increased expression of complement- and Fc-receptors can augment opsono-phagocytosis. A further level of neutrophil up-regulation occurs by increasing the functional life span of neutrophils by GM-CSF. Thus, by delaying neutrophil apoptosis, GM-CSF greatly extends the time over which neutrophils may function at inflammatory sites. GM-CSF can thus exert a variety of important regulatory controls of neutrophil function during bacterial infections. Both the number and the functional status of neutrophils is highly regulated by GM-CSF. It is also possible that GM-CSF produced within localised sites of acute inflammation or infection may attract, trap and then activate neutrophils within this site.
Collapse
Affiliation(s)
- G Fossati
- Department of Internal Medicine and Therapeutics, IRCCS S. Matteo H., Pavia, Italy
| | | | | | | | | | | | | |
Collapse
|
25
|
Edwards SW, Watson F, Gasmi L, Moulding DA, Quayle JA. Activation of human neutrophils by soluble immune complexes: role of Fc gamma RII and Fc gamma RIIIb in stimulation of the respiratory burst and elevation of intracellular Ca2+. Ann N Y Acad Sci 1997; 832:341-57. [PMID: 9704062 DOI: 10.1111/j.1749-6632.1997.tb46262.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 11/29/2022]
Abstract
Activation of control, unprimed neutrophils with soluble immune complexes fails to generate a respiratory burst. However, if the cells are primed with either tumor necrosis factor-alpha or granulocyte-macrophage colony-stimulating factor prior to addition of soluble immune complexes, then a rapid and transient burst of reactive oxidant secretion is observed. In unprimed neutrophils the soluble immune complexes stimulate an intracellular Ca2+ transient that arises from the mobilization of intracellular Ca2+. However, in primed cells, an "extra" intracellular Ca2+ signal is observed that arises from Ca2+ influx. After removal of Fc gamma RIIIb by treatment with pronase or PI-PLC, the soluble immune complexes fail to activate a respiratory burst in unprimed neutrophils and the "extra" Ca2+ signal is not observed. These results indicate that during priming Fc gamma RIIIb becomes functionally activated and thence its ligation leads to stimulated Ca2+ influx and the generation of intracellular signals that lead to NADPH oxidase activation. Experiments using Fab/F(ab')2 fragments to specifically crosslink either Fc gamma RII or Fc gamma RIIIb and experiments with neutrophils from an individual with Fc gamma RIIIb gene deficiency confirm this important function for Fc gamma RIIIb in neutrophil activation.
Collapse
Affiliation(s)
- S W Edwards
- School of Biological Sciences, University of Liverpool, United Kingdom.
| | | | | | | | | |
Collapse
|
26
|
Affiliation(s)
- D A Moulding
- Department of Biochemistry, University of Liverpool, U.K
| | | | | |
Collapse
|