1
|
Ajayi BE, Oboh B, Minari JB, Sexton DW, Sarker SD, Fatokun AA. Cola rostrata K. Schum. constituents induce cytotoxicity through reactive oxygen species generation and mitochondrial membrane depolarisation. Explor Target Antitumor Ther 2023; 4:1328-1344. [PMID: 38213537 PMCID: PMC10776592 DOI: 10.37349/etat.2023.00200] [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: 03/10/2023] [Accepted: 07/27/2023] [Indexed: 01/13/2024] Open
Abstract
Aim While the traditional use of Cola rostrata in treating illnesses and diseases has not been reported, the presence of cytotoxic principles has been reported in phylogenetically and biogeographically related species within the Cola genus. This study, therefore, evaluated the cytotoxic potential of extracts of the plant, and the associated cellular and molecular mechanisms. Methods Activity-based fractionation of the extracts was carried out and cytotoxicity was assessed in the human cervical cancer cell line, HeLa, and the transformed human lung cell line, MRC5-SV2, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay complemented with brightfield imaging. The 2',7'-dichlorofluorescein diacetate (DCFDA) assay was used to assess induction of cellular reactive oxygen species (ROS), while flow cytometry of 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide (JC-1)-stained cells assessed the loss of mitochondrial membrane potential (∆ΨM). Gas chromatography-mass spectrometry (GC-MS) analysis was carried out on an active fraction. Results Extracts of the fruit epicarp and leaf were cytotoxic against the cell lines. Half-maximal inhibitory concentration (IC50) values for the 48 h cytotoxicity of the ethanol extract of the epicarp against HeLa and MRC5-SV2 cells were 48.0 μg/mL ± 12.1 μg/mL and 40.4 μg/mL ± 7.2 μg/mL, respectively, while fractions from second-level partitioning of the hexane fraction of the leaf extract elicited cytotoxicity with IC50 values ranging from 12.8 μg/mL ± 1.0 μg/mL to 39.6 μg/mL ± 7.2 μg/mL in both cell lines, following 48 h treatment. GC-MS revealed the presence of seventeen compounds in a hexane fraction of the leaf extract, including even- and odd-chain fatty acids, the most abundant of which were n-hexadecanoic acid, decanoic acid 10-(2-hexylcyclopropyl); and octadecanoic acid. The mechanisms of cytotoxicity of most active fractions involved generation of ROS and mitochondrial membrane depolarisation. Conclusions The findings show that C. rostrata is rich in cytotoxic phytochemicals which could be isolated for developing new anti-cancer agents.
Collapse
Affiliation(s)
- Babatunde E. Ajayi
- Department of Cell Biology and Genetics, Faculty of Science, University of Lagos, Akoka, Lagos, Nigeria
- Department of Biochemistry, Faculty of Natural and Applied Sciences, Hallmark University, Ijebu-Itele, Ogun State, Nigeria
- Centre for Natural Products Discovery (CNPD), School of Pharmacy and Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, L3 3AF Liverpool, UK
| | - Bola Oboh
- Department of Cell Biology and Genetics, Faculty of Science, University of Lagos, Akoka, Lagos, Nigeria
| | - Joseph B. Minari
- Department of Cell Biology and Genetics, Faculty of Science, University of Lagos, Akoka, Lagos, Nigeria
| | - Darren W. Sexton
- School of Pharmacy and Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, L3 3AF Liverpool, UK
| | - Satyajit D. Sarker
- Centre for Natural Products Discovery (CNPD), School of Pharmacy and Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, L3 3AF Liverpool, UK
| | - Amos A. Fatokun
- Centre for Natural Products Discovery (CNPD), School of Pharmacy and Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, L3 3AF Liverpool, UK
| |
Collapse
|
2
|
Nolan A, Heaton RA, Adamova P, Cole P, Turton N, Gillham SH, Owens DJ, Sexton DW. Fluorescent characterization of differentiated myotubes using flow cytometry. Cytometry A 2023. [PMID: 38092660 DOI: 10.1002/cyto.a.24822] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/23/2023] [Accepted: 12/11/2023] [Indexed: 12/27/2023]
Abstract
Flow cytometry is routinely used in the assessment of skeletal muscle progenitor cell (myoblast) populations. However, a full gating strategy, inclusive of difficult to interpret forward and side scatter data, which documents cytometric analysis of differentiated myoblasts (myotubes) has not been reported. Beyond changes in size and shape, there are substantial metabolic and protein changes in myotubes allowing for their potential identification within heterogenous cell suspensions. To establish the utility of flow cytometry for determination of myoblasts and myotubes, C2C12 murine cell populations were assessed for cell morphology and metabolic reprogramming. Laser scatter, both forward (FSC; size) and side (SSC; granularity), measured cell morphology, while mitochondrial mass, reactive oxygen species (ROS) generation and DNA content were quantified using the fluorescent probes, MitoTracker green, CM-H2 DCFDA and Vybrant DyeCycle, respectively. Immunophenotyping for myosin heavy chain (MyHC) was utilized to confirm myotube differentiation. Cellular viability was determined using Annexin V/propidium iodide dual labelling. Fluorescent microscopy was employed to visualize fluorescence and morphology. Myotube and myoblast populations were resolvable through non-intuitive interpretation of laser scatter-based morphology assessment and mitochondrial mass and activity assessment. Myotubes appeared to have similar sizes to the myoblasts based on laser scatter but exhibited greater mitochondrial mass (159%, p < 0.0001), ROS production (303%, p < 0.0001), DNA content (18%, p < 0.001) and expression of MyHC (147%, p < 0.001) compared to myoblasts. Myotube sub-populations contained a larger viable cluster of cells which were unable to be fractionated from myoblast populations and a smaller population cluster which likely contains apoptotic bodies. Imaging of differentiated myoblasts that had transited through the flow cytometer revealed the presence of intact, 'rolled-up' myotubes, which would alter laser scatter properties and potential transit through the laser beam. Our results indicate that myotubes can be analyzed successfully using flow cytometry. Increased mitochondrial mass, ROS and DNA content are key features that correlate with MyHC expression but due to myotubes 'rolling up' during flow cytometric analysis, laser scatter determination of size is not positively correlated; a phenomenon observed with some size determination particles and related to surface properties of said particles. We also note a greater heterogeneity of myotubes compared to myoblasts as evidenced by the 2 distinct sub-populations. We suggest that acoustic focussing may prove effective in identifying myotube sub populations compared to traditional hydrodynamic focussing.
Collapse
Affiliation(s)
- Andy Nolan
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Robert A Heaton
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Petra Adamova
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Paige Cole
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Nadia Turton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Scott H Gillham
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Daniel J Owens
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Darren W Sexton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| |
Collapse
|
3
|
Islam Y, Ehtezazi P, Cashmore A, Marinsalda E, Leach AG, Coxon CR, Fatokun AA, Sexton DW, Khan I, Zouganelis G, Downing J, Pluchino S, Sivakumaran M, Teixido M, Ehtezazi T. The Inclusion of a Matrix Metalloproteinase-9 Responsive Sequence in Self-assembled Peptide-based Brain-Targeting Nanoparticles Improves the Efficiency of Nanoparticles Crossing the Blood-Brain Barrier at Elevated MMP-9 Levels. J Pharm Sci 2020; 110:1349-1364. [PMID: 33333144 DOI: 10.1016/j.xphs.2020.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 10/20/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/18/2022]
Abstract
This study investigated whether the inclusion of a matrix metalloproteinase-9 (MMP-9) responsive sequence in self-assembled peptide-based brain-targeting nanoparticles (NPs) would enhance the blood-brain barrier (BBB) penetration when MMP-9 levels are elevated both in the brain and blood circulation. Brain-targeting peptides were conjugated at the N-terminus to MMP-9-responsive peptides, and these were conjugated at the N-terminus to lipid moiety (cholesteryl chloroformate or palmitic acid). Two constructs did not have MMP-9-responsive peptides. NPs were characterised for size, charge, critical micelle concentration, toxicity, blood compatibility, neural cell uptake, release profiles, and in vitro BBB permeability simulating normal or elevated MMP-9 levels. The inclusion of MMP-9-sensitive sequences did not improve the release of a model drug in the presence of active MMP-9 from NPs compared to distilled water. 19F NMR studies suggested the burial of MMP-9-sensitive sequences inside the NPs making them inaccessible to MMP-9. Only cholesterol-GGGCKAPETALC (responsive to MMP-9) NPs showed <5% haemolysis, <1 pg/mL release of IL-1β at 500 μg/mL from THP1 cells, with 70.75 ± 5.78% of NPs crossing the BBB at 24 h in presence of active MMP-9. In conclusion, brain-targeting NPs showed higher transport across the BBB model when MMP-9 levels were elevated and the brain-targeting ligand was responsive to MMP-9.
Collapse
Affiliation(s)
- Yamir Islam
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Parinaz Ehtezazi
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Andrew Cashmore
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Elena Marinsalda
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Andrew G Leach
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Christopher R Coxon
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Amos A Fatokun
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Darren W Sexton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Iftikhar Khan
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Georgios Zouganelis
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - James Downing
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
| | - Stefano Pluchino
- Department of Clinical Neurosciences, Clifford Allbutt Building - Cambridge Biosciences Campus and NIHR Biomedical Research Centre, University of Cambridge, Hills Road, CB2 0HA Cambridge, UK
| | - Muttuswamy Sivakumaran
- Department of Haematology, Peterborough City Hospital, Edith Cavell Campus, Bretton Gate Peterborough, PE3 9GZ, Peterborough, UK
| | - Meritxell Teixido
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Touraj Ehtezazi
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK.
| |
Collapse
|
4
|
Heaton RA, Heales S, Rahman K, Sexton DW, Hargreaves I. The Effect of Cellular Coenzyme Q 10 Deficiency on Lysosomal Acidification. J Clin Med 2020; 9:jcm9061923. [PMID: 32575494 PMCID: PMC7355799 DOI: 10.3390/jcm9061923] [Citation(s) in RCA: 16] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 12/21/2022] Open
Abstract
Coenzyme Q10 (CoQ10) deficiency currently represents the only treatable mitochondrial disorder, however, little is known about how it may affect other organelles. The lysosome has been found to have a large concentration of CoQ10 localised at its membrane; additionally, it has been suggested that it plays a role in the normal acidification of the lysosomal lumen. As a result, in this study we assessed the effect of CoQ10 deficiency on lysosomal acidification. In order to investigate this, a neuronal cell model of CoQ10 deficiency was established via the treatment of SH-SY5Y cells with para-aminobenzoic acid (PABA). This method works through the competitive inhibition of the CoQ10 biosynthetic pathway enzyme, CoQ2. A single 1 mM (5 days) treatment with PABA resulted in a decrease of up to 58% in cellular CoQ10 (p < 0.05). It was found that this resulted in a significant decrease in fluorescence of both the LysoSensor (23%) and LysoTracker (35%) probes used to measure lysosomal pH (p < 0.05). It was found that subsequent treatment with CoQ10 (5 µM, 3 days) was able to restore cellular CoQ10 concentration (p < 0.005), which was associated with an increase in fluorescence from both probes to around 90% of controls (p < 0.05), suggesting a restoration of lysosomal pH. This study provides insights into the association between lysosomal pH and cellular CoQ10 status and the possibility that a deficit in the status of this isoprenoid may result in an impairment of lysosomal acidification.
Collapse
Affiliation(s)
- Robert A. Heaton
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK; (K.R.); (D.W.S.); (I.H.)
- Correspondence:
| | - Simon Heales
- Neurometabolic Unit, National Hospital, Queen Square, London WC1N 3BG, UK;
- Enzyme Unit, Chemical Pathology, NIHR BRC Great Ormond Street Hospital, Foundation Trust, London WC1N 3JH, UK
- NIHR BRC and UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
| | - Khalid Rahman
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK; (K.R.); (D.W.S.); (I.H.)
| | - Darren W. Sexton
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK; (K.R.); (D.W.S.); (I.H.)
| | - Iain Hargreaves
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK; (K.R.); (D.W.S.); (I.H.)
| |
Collapse
|
5
|
Richardson A, Powell AK, Sexton DW, Parsons JL, Reynolds NJ, Ross K. microRNA‐184 is induced by store‐operated calcium entry and regulates early keratinocyte differentiation. J Cell Physiol 2020; 235:6854-6861. [DOI: 10.1002/jcp.29579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 01/07/2020] [Indexed: 01/11/2023]
Affiliation(s)
- Adam Richardson
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores University Liverpool UK
| | - Andrew K. Powell
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores University Liverpool UK
| | - Darren W. Sexton
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores University Liverpool UK
| | - Jason L. Parsons
- Department of Molecular and Clinical Cancer Medicine, Cancer Research CentreUniversity of Liverpool Liverpool UK
| | - Nick J. Reynolds
- Dermatological Sciences, Institute of Cellular MedicineNewcastle University Newcastle upon Tyne UK
- Department of Dermatology, Royal Victoria InfirmaryNewcastle Hospitals NHS Foundation Trust Newcastle upon Tyne UK
| | - Kehinde Ross
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores University Liverpool UK
| |
Collapse
|
6
|
Abstract
Nanoparticle(NP)-based materials have breakthrough applications in many fields of life, such as in engineering, communications and textiles industries; food and bioenvironmental applications; medicines and cosmetics, etc. Biomedical applications of NPs are very active areas of research with successful translation to pharmaceutical and clinical uses overcoming both pharmaceutical and clinical challenges. Although the attractiveness and enhanced applications of these NPs stem from their exceptional properties at the nanoscale size, i.e. 1-1000 nm, they exhibit completely different physicochemical profiles and, subsequently, toxicological profiles from their parent bulk materials. Hence, the clinical evaluation and toxicological assessment of NPs interactions within biological systems are continuously evolving to ensure their safety at the nanoscale. The pulmonary system is one of the primary routes of exposure to airborne NPs either intentionally, via aerosolized nanomedicines targeting pulmonary pathologies such as cancer or asthma, or unintentionally, via natural NPs and anthropogenic (man-made) NPs. This review presents the state-of-the-art, contemporary challenges, and knowledge gaps in the toxicological assessment of NPs interactions with the pulmonary system. It highlights the main mechanisms of NP toxicity, factors influencing their toxicity, the different toxicological assessment methods and their drawbacks, and the recent NP regulatory guidelines based on literature collected from the research pool of NPs interactions with lung cell lines, in vivo inhalation studies, and clinical trials.
Collapse
Affiliation(s)
- Nashwa M Osman
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Darren W Sexton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Imran Y Saleem
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| |
Collapse
|
7
|
Bidula S, Sexton DW, Schelenz S. Ficolins and the Recognition of Pathogenic Microorganisms: An Overview of the Innate Immune Response and Contribution of Single Nucleotide Polymorphisms. J Immunol Res 2019; 2019:3205072. [PMID: 30868077 PMCID: PMC6379837 DOI: 10.1155/2019/3205072] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/29/2018] [Accepted: 12/24/2018] [Indexed: 12/19/2022] Open
Abstract
Ficolins are innate pattern recognition receptors (PRR) and play integral roles within the innate immune response to numerous pathogens throughout the circulation, as well as within organs. Pathogens are primarily removed by direct opsonisation following the recognition of cell surface carbohydrates and other immunostimulatory molecules or via the activation of the lectin complement pathway, which results in the deposition of C3b and the recruitment of phagocytes. In recent years, there have been a number of studies implicating ficolins in the recognition and removal of numerous bacterial, viral, fungal, and parasitic pathogens. Moreover, there has been expanding evidence highlighting that mutations within these key immune proteins, or the possession of particular haplotypes, enhance susceptibility to colonization by pathogens and dysfunctional immune responses. This review will therefore encompass previous knowledge on the role of ficolins in the recognition of bacterial and viral pathogens, while acknowledging the recent advances in the immune response to fungal and parasitic infections. Additionally, we will explore the various genetic susceptibility factors that predispose individuals to infection.
Collapse
Affiliation(s)
- Stefan Bidula
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Darren W. Sexton
- School of Pharmacy and Biomolecular Science, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
| | - Silke Schelenz
- Department of Microbiology, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
| |
Collapse
|
8
|
Dubourg A, Xia D, Winpenny JP, Al Naimi S, Bouzid M, Sexton DW, Wastling JM, Hunter PR, Tyler KM. Giardia secretome highlights secreted tenascins as a key component of pathogenesis. Gigascience 2018; 7:1-13. [PMID: 29385462 PMCID: PMC5887430 DOI: 10.1093/gigascience/giy003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [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: 06/12/2017] [Accepted: 01/17/2018] [Indexed: 11/13/2022] Open
Abstract
Background Giardia is a protozoan parasite of public health relevance that causes gastroenteritis in a wide range of hosts. Two genetically distinct lineages (assemblages A and B) are responsible for the human disease. Although it is clear that differences in virulence occur, the pathogenesis and virulence of Giardia remain poorly understood. Results The genome of Giardia is believed to contain open reading frames that could encode as many as 6000 proteins. By successfully applying quantitative proteomic analyses to the whole parasite and to the supernatants derived from parasite culture of assemblages A and B, we confirm expression of ∼1600 proteins from each assemblage, the vast majority of which are common to both lineages. To look for signature enrichment of secreted proteins, we considered the ratio of proteins in the supernatant compared with the pellet, which defined a small group of enriched proteins, putatively secreted at a steady state by cultured growing trophozoites of both assemblages. This secretome is enriched with proteins annotated to have N-terminal signal peptide. The most abundant secreted proteins include known virulence factors such as cathepsin B cysteine proteases and members of a Giardia superfamily of cysteine-rich proteins that comprise variant surface proteins, high-cysteine membrane proteins, and a new class of virulence factors, the Giardia tenascins. We demonstrate that physiological function of human enteric epithelial cells is disrupted by such soluble factors even in the absence of the trophozoites. Conclusions We are able to propose a straightforward model of Giardia pathogenesis incorporating key roles for the major Giardia-derived soluble mediators.
Collapse
Affiliation(s)
- Audrey Dubourg
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Dong Xia
- Department of Infection Biology, Institute of Infection and Global Health, Faculty of Health and Life Sciences, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool, L3 5RF, UK.,Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, University of London, London, NW1 0TU, UK
| | - John P Winpenny
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Suha Al Naimi
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Department of Science and Technology, Faculty of Health and Science, James Hehir Building, Neptune Quay, University of Suffolk, Ipswich, IP4 1QJ, UK
| | - Maha Bouzid
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Darren W Sexton
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Jonathan M Wastling
- Department of Infection Biology, Institute of Infection and Global Health, Faculty of Health and Life Sciences, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool, L3 5RF, UK.,Faculty of Natural Sciences, Keele University, Staffordshire, ST5 5BG, UK
| | - Paul R Hunter
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Kevin M Tyler
- NIHR Health Protection Research Unit in Gastrointestinal Infections, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| |
Collapse
|
9
|
Hanson K, Robinson SD, Al-Yousuf K, Hendry AE, Sexton DW, Sherwood V, Wheeler GN. Correction: The anti-rheumatic drug, leflunomide, synergizes with MEK inhibition to suppress melanoma growth. Oncotarget 2018; 9:36645. [PMID: 30564304 PMCID: PMC6290961 DOI: 10.18632/oncotarget.26415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Kimberley Hanson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Stephen D Robinson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Karamallah Al-Yousuf
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Present address: Division of Cancer Sciences, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Adam E Hendry
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Darren W Sexton
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Present address: Pharmacy and Biomedical Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Victoria Sherwood
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Present address: Division of Cancer Sciences, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Grant N Wheeler
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| |
Collapse
|
10
|
Hanson K, Robinson SD, Al-Yousuf K, Hendry AE, Sexton DW, Sherwood V, Wheeler GN. The anti-rheumatic drug, leflunomide, synergizes with MEK inhibition to suppress melanoma growth. Oncotarget 2017; 9:3815-3829. [PMID: 29423085 PMCID: PMC5790502 DOI: 10.18632/oncotarget.23378] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 05/27/2017] [Accepted: 11/26/2017] [Indexed: 01/04/2023] Open
Abstract
Cutaneous melanoma, which develops from the pigment producing cells called melanocytes, is the most deadly form of skin cancer. Unlike the majority of other cancers, the incidence rates of melanoma are still on the rise and the treatment options currently available are being hindered by resistance, limited response rates and adverse toxicity. We have previously shown that an FDA approved drug leflunomide, used for rheumatoid arthritis (RA), also holds potential therapeutic value in treating melanoma especially if used in combination with the mutant BRAF inhibitor, vemurafenib. We have further characterized the function of leflunomide and show that the drug reduces the number of viable cells in both wild-type and BRAFV600E mutant melanoma cell lines. Further experiments have revealed leflunomide reduces cell proliferation and causes cells to arrest in G1 of the cell cycle. Cell death assays show leflunomide causes apoptosis at treatment concentrations of 25 and 50 µM. To determine if leflunomide could be used combinatorialy with other anti-melanoma drugs, it was tested in combination with the MEK inhibitor, selumetinib. This combination showed a synergistic effect in the cell lines tested. This drug combination led to an enhanced decrease in tumor size when tested in vivo compared to either drug alone, demonstrating its potential as a novel combinatorial therapy for melanoma.
Collapse
Affiliation(s)
- Kimberley Hanson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Stephen D Robinson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Karamallah Al-Yousuf
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Present address: Division of Cancer Sciences, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Adam E Hendry
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Darren W Sexton
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Present address: Pharmacy and Biomedical Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Victoria Sherwood
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Present address: Division of Cancer Sciences, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Grant N Wheeler
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| |
Collapse
|
11
|
Kotecha J, Shulgina L, Sexton DW, Atkins CP, Wilson AM. Plasma Vascular Endothelial Growth Factor Concentration and Alveolar Nitric Oxide as Potential Predictors of Disease Progression and Mortality in Idiopathic Pulmonary Fibrosis. J Clin Med 2016; 5:jcm5090080. [PMID: 27618114 PMCID: PMC5039483 DOI: 10.3390/jcm5090080] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/15/2016] [Accepted: 09/02/2016] [Indexed: 12/12/2022] Open
Abstract
Background: Declining lung function signifies disease progression in idiopathic pulmonary fibrosis (IPF). Vascular endothelial growth factor (VEGF) concentration is associated with declining lung function in 6 and 12-month studies. Alveolar nitric oxide concentration (CANO) is increased in patients with IPF, however its significance is unclear. This study investigated whether baseline plasma VEGF concentration and CANO are associated with disease progression or mortality in IPF. Methods: 27 IPF patients were studied (maximum follow-up 65 months). Baseline plasma VEGF concentration, CANO and pulmonary function tests (PFTs) were measured. PFTs were performed the preceding year and subsequent PFTs and data regarding mortality were collected. Disease progression was defined as one of: death, relative decrease of ≥10% in baseline forced vital capacity (FVC) % predicted, or relative decrease of ≥15% in baseline single breath diffusion capacity of carbon monoxide (TLCO-SB) % predicted. Results: Plasma VEGF concentration was not associated with progression-free survival or mortality. There was a trend towards shorter time to disease progression and death with higher CANO. CANO was significantly higher in patients with previous declining versus stable lung function. Conclusion: The role of VEGF in IPF remains uncertain. It may be of value to further investigate CANO in IPF.
Collapse
Affiliation(s)
- Jalpa Kotecha
- Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, Norfolk, UK.
| | - Ludmila Shulgina
- Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, Norfolk, UK.
| | - Darren W Sexton
- Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, Norfolk, UK.
| | - Christopher P Atkins
- Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, Norfolk, UK.
| | - Andrew M Wilson
- Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, Norfolk, UK.
| |
Collapse
|
12
|
Steverding D, Tyler KM, Sexton DW. Evaluation of marking of peer marking in oral presentation. Perspect Med Educ 2016; 5:103-107. [PMID: 26951165 PMCID: PMC4839009 DOI: 10.1007/s40037-016-0254-8] [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] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND Peer marking is an important skill for students, helping them to understand the process of learning and assessment. This method is increasingly used in medical education, particularly in formative assessment. However, the use of peer marking in summative assessment is not widely adopted because many teachers are concerned about biased marking by students of their peers. OBJECTIVE The aim of this study was to investigate whether marking of summative peer assessment can improve the reliability of peer marking. METHODS In a retrospective analysis, the peer-marking results of a summative assessment of oral presentations of two cohorts of students were compared. One group of students was told that their peer marks would be assessed against a benchmark consisting of the average of examiner marks and that these scores together with the peer and examiner marks would form their final exam results. The other group of students were just informed that their final exam results would be determined based on the examiner and peer marks. RESULTS Based on examiner marks, both groups of students performed similarly in their summative assessment, agreement between student markers was less consistent and more polar than the examiners. When compared with the examiners, students who were told that their peer marking would be scored were more generous markers (their average peer mark was 2.4 % points higher than the average examiner mark) while students who were not being scored on their marking were rather harsh markers (their average peer mark was 4.2 % points lower than the average examiner mark), with scoring of the top-performing students most affected. CONCLUSIONS Marking of peer marking had a small effect on the marking conduct of students in summative assessment of oral presentation but possibly indicated a more balanced marking performance.
Collapse
Affiliation(s)
- Dietmar Steverding
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK.
| | - Kevin M Tyler
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Darren W Sexton
- Norwich Medical School, currently: School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| |
Collapse
|
13
|
Bidula S, Sexton DW, Schelenz S. Serum opsonin ficolin-A enhances host-fungal interactions and modulates cytokine expression from human monocyte-derived macrophages and neutrophils following Aspergillus fumigatus challenge. Med Microbiol Immunol 2016; 205:133-42. [PMID: 26337048 DOI: 10.1007/s00430-015-0435-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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: 04/02/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
Invasive aspergillosis is a devastating invasive fungal disease associated with a high mortality rate in the immunocompromised, such as leukaemia patients, transplant patients and those with HIV/AIDS. The rodent serum orthologue of human L-ficolin, ficolin-A, can bind to and opsonize Aspergillus fumigatus, the pathogen that causes invasive aspergillosis, and may participate in fungal defence. Using human monocyte-derived macrophages and neutrophils isolated from healthy donors, we investigated conidial association and fungal viability by flow cytometry and microscopy. Additionally, cytokine production was measured via cytometric bead arrays. Ficolin-A opsonization was observed to significantly enhance association of conidia, while also inhibiting hyphal growth and contributing to increased fungal killing following incubation with monocyte-derived macrophages and neutrophils. Additionally, ficolin-A opsonization was capable of manifesting a decrease in IL-8, IL-1β, IL-6, IL-10 and TNF-α production from MDM and IL-1β, IL-6 and TNF-α from neutrophils 24 h post-infection. In conclusion, rodent ficolin-A is functionally comparable to human L-ficolin and is capable of modulating the innate immune response to A. fumigatus, down-regulating cytokine production and could play an important role in airway immunity.
Collapse
Affiliation(s)
- Stefan Bidula
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK
| | - Darren W Sexton
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
- School of Pharmacy and Biomolecular Science, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
| | - Silke Schelenz
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
- Department of Microbiology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK.
| |
Collapse
|
14
|
Wang W, He Y, Yu G, Li B, Sexton DW, Wileman T, Roberts AA, Hamilton CJ, Liu R, Chao Y, Shan Y, Bao Y. Sulforaphane Protects the Liver against CdSe Quantum Dot-Induced Cytotoxicity. PLoS One 2015; 10:e0138771. [PMID: 26402917 PMCID: PMC4581733 DOI: 10.1371/journal.pone.0138771] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [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: 02/16/2015] [Accepted: 07/10/2015] [Indexed: 12/28/2022] Open
Abstract
The potential cytotoxicity of cadmium selenide (CdSe) quantum dots (QDs) presents a barrier to their use in biomedical imaging or as diagnostic and therapeutic agents. Sulforaphane (SFN) is a chemoprotective compound derived from cruciferous vegetables which can up-regulate antioxidant enzymes and induce apoptosis and autophagy. This study reports the effects of SFN on CdSe QD-induced cytotoxicity in immortalised human hepatocytes and in the livers of mice. CdSe QDs induced dose-dependent cell death in hepatocytes with an IC50 = 20.4 μM. Pre-treatment with SFN (5 μM) increased cell viability in response to CdSe QDs (20 μM) from 49.5 to 89.3%. SFN induced a pro-oxidant effect characterized by depletion of intracellular reduced glutathione during short term exposure (3–6 h), followed by up-regulation of antioxidant enzymes and glutathione levels at 24 h. SFN also caused Nrf2 translocation into the nucleus, up-regulation of antioxidant enzymes and autophagy. siRNA knockdown of Nrf2 suggests that the Nrf2 pathway plays a role in the protection against CdSe QD-induced cell death. Wortmannin inhibition of SFN-induced autophagy significantly suppressed the protective effect of SFN on CdSe QD-induced cell death. Moreover, the role of autophagy in SFN protection against CdSe QD-induced cell death was confirmed using mouse embryonic fibroblasts lacking ATG5. CdSe QDs caused significant liver damage in mice, and this was decreased by SFN treatment. In conclusion, SFN attenuated the cytotoxicity of CdSe QDs in both human hepatocytes and in the mouse liver, and this protection was associated with the induction of Nrf2 pathway and autophagy.
Collapse
Affiliation(s)
- Wei Wang
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Yan He
- Department of Pathology, Harbin Medical University, Harbin, Heilongjiang, P. R. China
| | - Guodong Yu
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Baolong Li
- Center of Safety Evaluation of Drugs, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang, P. R. China
| | - Darren W Sexton
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Thomas Wileman
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Alexandra A Roberts
- School of Pharmacy, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Chris J Hamilton
- School of Pharmacy, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Ruoxi Liu
- School of Chemistry, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Yimin Chao
- School of Chemistry, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Yujuan Shan
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, P. R. China
| | - Yongping Bao
- Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| |
Collapse
|
15
|
Jacques RO, Mills SC, Cazzonatto Zerwes P, Fagade FO, Green JE, Downham S, Sexton DW, Mueller A. Dynamin function is important for chemokine receptor-induced cell migration. Cell Biochem Funct 2015; 33:407-14. [DOI: 10.1002/cbf.3131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/22/2015] [Indexed: 12/31/2022]
Affiliation(s)
- Richard O. Jacques
- School of Pharmacy; University of East Anglia, Norwich Research Park; Norwich UK
| | - Shirley C. Mills
- School of Pharmacy; University of East Anglia, Norwich Research Park; Norwich UK
| | | | - Feyisope O. Fagade
- School of Pharmacy; University of East Anglia, Norwich Research Park; Norwich UK
| | - John E. Green
- School of Pharmacy; University of East Anglia, Norwich Research Park; Norwich UK
| | - Scott Downham
- School of Pharmacy; University of East Anglia, Norwich Research Park; Norwich UK
| | - Darren W. Sexton
- Norwich Medical School; University of East Anglia, Norwich Research Park; Norwich UK
- School of Pharmacy and Biomolecular Science; Liverpool John Moores University; Liverpool UK
| | - Anja Mueller
- School of Pharmacy; University of East Anglia, Norwich Research Park; Norwich UK
| |
Collapse
|
16
|
Bidula S, Sexton DW, Yates M, Abdolrasouli A, Shah A, Wallis R, Reed A, Armstrong-James D, Schelenz S. H-ficolin binds Aspergillus fumigatus leading to activation of the lectin complement pathway and modulation of lung epithelial immune responses. Immunology 2015; 146:281-91. [PMID: 26133042 DOI: 10.1111/imm.12501] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/25/2015] [Accepted: 06/25/2015] [Indexed: 01/07/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that typically infects the lungs of immunocompromised patients leading to a high mortality. H-Ficolin, an innate immune opsonin, is produced by type II alveolar epithelial cells and could participate in lung defences against infections. Here, we used the human type II alveolar epithelial cell line, A549, to determine the involvement of H-ficolin in fungal defence. Additionally, we investigated the presence of H-ficolin in bronchoalveolar lavage fluid from transplant patients during pneumonia. H-Ficolin exhibited demonstrable binding to A. fumigatus conidia via l-fucose, d-mannose and N-acetylglucosamine residues in a calcium- and pH-dependent manner. Moreover, recognition led to lectin complement pathway activation and enhanced fungal association with A549 cells. Following recognition, H-ficolin opsonization manifested an increase in interleukin-8 production from A549 cells, which involved activation of the intracellular signalling pathways mitogen-activated protein kinase MAPK kinase 1/2, p38 MAPK and c-Jun N-terminal kinase. Finally, H-ficolin concentrations were significantly higher in bronchoalveolar lavage fluid of patients with lung infections compared with control subjects (n = 16; P = 0·00726). Receiver operating characteristics curve analysis further highlighted the potential of H-ficolin as a diagnostic marker for lung infection (area under the curve = 0·77; P < 0·0001). Hence, H-ficolin participates in A. fumigatus defence through the activation of the lectin complement pathway, enhanced fungus-host interactions and modulated immune responses.
Collapse
Affiliation(s)
- Stefan Bidula
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK.,Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Darren W Sexton
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK.,School of Pharmacy and Biomolecular Science, Liverpool John Moores University, Liverpool, UK
| | - Matthew Yates
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Alireza Abdolrasouli
- Section of Infectious Diseases and Immunity, Imperial College London, London, UK
| | - Anand Shah
- Section of Infectious Diseases and Immunity, Imperial College London, London, UK
| | - Russell Wallis
- Departments of Infection, Immunity and Inflammation and Biochemistry, University of Leicester, Leicester, UK
| | - Anna Reed
- Department of Lung Transplantation, Harefield Hospital, Middlesex, UK
| | | | - Silke Schelenz
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK.,Department of Microbiology, Royal Brompton Hospital, London, UK
| |
Collapse
|
17
|
Bidula S, Sexton DW, Abdolrasouli A, Shah A, Reed A, Armstrong-James D, Schelenz S. The serum opsonin L-ficolin is detected in lungs of human transplant recipients following fungal infections and modulates inflammation and killing of Aspergillus fumigatus. J Infect Dis 2015; 212:234-46. [PMID: 25612732 DOI: 10.1093/infdis/jiv027] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 01/08/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Invasive aspergillosis (IA) is a life-threatening systemic fungal infection in immunocompromised individuals that is caused by Aspergillus fumigatus. The human serum opsonin, L-ficolin, has been observed to recognize A. fumigatus and could participate in fungal defense. METHODS Using lung epithelial cells, primary human monocyte-derived macrophages (MDMs), and neutrophils from healthy donors, we assessed phagocytosis and killing of L-ficolin-opsonized live A. fumigatus conidia by flow cytometry and microscopy. Additionally, cytokines were measured by cytometric bead array, and L-ficolin was measured in bronchoalveolar lavage (BAL) fluid from lung transplant recipients by enzyme-linked immunosorbent assay. RESULTS L-ficolin opsonization increased conidial uptake and enhanced killing of A. fumigatus by MDMs and neutrophils. Opsonization was also shown to manifest an increase in interleukin 8 release from A549 lung epithelial cells but decreased interleukin 1β, interleukin 6, interleukin 8, interleukin 10, and tumor necrosis factor α release from MDMs and neutrophils 24 hours after infection. The concentration of L-ficolin in BAL fluid from patients with fungal infection was significantly higher than that for control subjects (P = .00087), and receiving operating characteristic curve analysis highlighted the diagnostic potential of L-ficolin for lung infection (area under the curve, 0.842; P < .0001). CONCLUSIONS L-ficolin modulates the immune response to A. fumigatus. Additionally, for the first time, L-ficolin has been demonstrated to be present in human lungs.
Collapse
Affiliation(s)
- Stefan Bidula
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich
| | - Darren W Sexton
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich
| | | | - Anand Shah
- Section of Infectious Diseases and Immunity, Imperial College London
| | - Anna Reed
- Department of Lung Transplantation, Harefield Hospital, Middlesex, United Kingdom
| | | | - Silke Schelenz
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Department of Microbiology, Royal Brompton Hospital, London
| |
Collapse
|
18
|
Campwala H, Sexton DW, Crossman DC, Fountain SJ. P2Y₆ receptor inhibition perturbs CCL2-evoked signalling in human monocytic and peripheral blood mononuclear cells. J Cell Sci 2014; 127:4964-73. [PMID: 25271060 PMCID: PMC4231309 DOI: 10.1242/jcs.159012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The chemokine CCL2 serves to target circulating monocytes and other leukocytes to tissue during innate immune responses, and modulates the progression of chronic inflammatory disease through activation of the receptor CCR2. Here, we show that co-activation of the P2Y₆ purinergic receptor (encoded by P2RY₆) occurs when THP-1 cells and human peripheral blood mononuclear cells sense CCL2 through CCR2. Furthermore, P2Y₆ receptor activation accounts for ∼80% of the intracellular Ca²⁺ signal evoked by CCL2. Scavenging extracellular nucleotides with apyrase caused a fourfold reduction in THP-1 sensitivity to CCL2, whereas inhibition of CD39-like ectonucleotidases potentiated CCL2-evoked Ca²⁺ responses. Pharmacological inhibition of P2Y₆ impaired CCL2-evoked Ca²⁺ signalling and chemotaxis in peripheral blood mononuclear cells and THP-1 cells. Furthermore, stable P2Y₆ receptor knockdown (of twofold) in THP-1 cells impaired CCL2-evoked Ca²⁺ signalling, chemotaxis and adhesion to TNFα-treated HUVECs. We demonstrate that THP-1 cells rapidly secrete ATP during signalling downstream of the CCL2-CCR2 axis and suggest this might act as a mechanism for P2Y₆ receptor co-activation following CCL2 activation of the CCR2 receptor. The discovery that P2Y₆ receptor mediates leukocyte responsiveness to CCL2 represents a new mechanism by which to modulate CCL2 signals.
Collapse
Affiliation(s)
- Hinnah Campwala
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Darren W Sexton
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - David C Crossman
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Samuel J Fountain
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| |
Collapse
|
19
|
Brockwell C, Ampikaipakan S, Sexton DW, Price D, Freeman D, Thomas M, Ali M, Wilson AM. Adjunctive treatment with oral AKL1, a botanical nutraceutical, in chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 2014; 9:715-21. [PMID: 25031533 PMCID: PMC4096458 DOI: 10.2147/copd.s54276] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose The objective of this pilot trial was to evaluate the safety and efficacy of AKL1, a patented botanical formulation containing extracts of Picrorhiza kurroa, Ginkgo biloba, and Zingiber officinale, as add-on therapy for patients with chronic obstructive pulmonary disease (COPD) and chronic cough. Patients and methods This randomized, double-blind, placebo-controlled trial enrolled male and female patients >18 years old with COPD and Leicester Cough Questionnaire (LCQ) score of <18. The 10-week study period comprised a 2-week single-blind placebo run-in period followed by add-on treatment with AKL1 or placebo twice daily for 8 weeks. The primary study endpoint was the change from week 0 to week 8 in cough-related health status, as assessed by the LCQ. Results Of 33 patients enrolled, 20 were randomized to AKL1 and 13 to placebo. Patients included 19 (58%) men and 14 (42%) women of mean (standard deviation [SD]) age of 67 (9.4) years; 15 (45%) patients were smokers and 16 (49%) were ex-smokers. The mean (SD) change from baseline in LCQ score at 8 weeks was 2.3 (4.9) in the AKL1 group and 0.6 (3.7) in the placebo group, with mean difference in change of 1.8 (95% confidence interval: −1.5 to 5.1; P=0.28). The St George’s Respiratory Questionnaire score improved substantially in the AKL1 treatment group by a mean (SD) of −7.7 (11.7) versus worsening in the placebo group (+1.5 [9.3]), with mean difference in change of −9.2 (95% confidence interval: −19.0 to 0.6; P=0.064). There were no significant differences between treatment groups in change from baseline to week 8 in other patient-reported measures, lung function, or the 6-minute walk distance. Conclusion Further study is needed with a larger patient population and over a longer duration to better assess the effects of add-on therapy with AKL1 in COPD.
Collapse
Affiliation(s)
| | - Sundari Ampikaipakan
- Norwich Medical School, University of East Anglia, Norwich, UK ; Norfolk and Norwich University Hospital Foundation Trust, Norwich, UK
| | - Darren W Sexton
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - David Price
- Academic Primary Care, University of Aberdeen, Aberdeen, UK ; Research in Real Life, Cambridge, UK
| | | | - Mike Thomas
- Primary Care Research, Aldermoor Health Centre, University of Southampton, Southampton, UK
| | | | - Andrew M Wilson
- Norwich Medical School, University of East Anglia, Norwich, UK ; Norfolk and Norwich University Hospital Foundation Trust, Norwich, UK
| |
Collapse
|
20
|
Bradley JM, Squirrell F, Sexton DW, O’Connell MA. 28. Cytokine 2013. [DOI: 10.1016/j.cyto.2013.06.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
21
|
Schelenz S, Kirchhof N, Bidula S, Wallis R, Sexton DW. Opsonizing properties of rat ficolin-A in the defence against Cryptococcus neoformans. Immunobiology 2013; 218:477-83. [PMID: 22789560 DOI: 10.1016/j.imbio.2012.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 01/28/2023]
Abstract
Cryptococcus neoformans is a pathogenic fungus causing life threatening infections in humans. The present in vitro study aimed to investigate the opsonizing properties of a well characterized serum ficolin (rat ficolin-A), a member of carbohydrate-recognition molecules of the innate immune system, in the defence against this fungal pathogen. Using flow cytometric analysis we have been able to demonstrate that ficolin-A readily binds to two different acapsular C. neoformans serotypes (representative of the primary infectious form of this fungus) whereas the encapsulated forms are not being recognized. The ficolin-A binding was concentration dependent and inhibited by the acetylated sugars N-acetyleglucosamine and N-acetylegalactosamine but less so by galactose, glucose and mannan. The binding was enhanced at acidic pHs (5.7 and 4.7) compared to physiological pH (7.4) which may indicate that the carbohydrate recognizing fibrinogen-like domains of ficolins undergo conformational changes providing more efficient binding at sites of inflammation where the pH is much lower than normal. We further assessed the biological consequence of the ficolin-A recognition of acapsular C. neoformans by investigating their interaction with lung epithelial cells (type II pneumocytes cell line A549). Flow cytometric analysis demonstrated that ficolin-A opsonized acapsular C. neoformans showed significantly increased adherence to A549 cells when exposed to acidic conditions compared to the unopsonized controls (p=0.04). We conclude that ficolin-A binds acapsular C. neoformans via their carbohydrate recognizing fibrinogen-like domains leading to enhanced uptake by lung epithelial cells in vitro.
Collapse
Affiliation(s)
- Silke Schelenz
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom.
| | | | | | | | | |
Collapse
|
22
|
Steverding D, Sexton DW. Trypanocidal activity of salinomycin is due to sodium influx followed by cell swelling. Parasit Vectors 2013; 6:78. [PMID: 23517602 PMCID: PMC3621689 DOI: 10.1186/1756-3305-6-78] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [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: 01/08/2013] [Accepted: 03/18/2013] [Indexed: 01/27/2023] Open
Abstract
Background The few currently available drugs for treatment of African trypanosomiasis are outdated and show problems with toxicity and resistance. Hence, there is an urgent need for the discovery and development of new anti-trypanosomal agents. Findings In this study, the ionophorous antibiotic salinomycin was investigated for its trypanocidal activity in vitro using culture-adapted bloodstream forms of Trypanosoma brucei. The concentrations of salinomycin to reduce the growth rate by 50% and to kill the parasites were 0.31 μM and 1 μM, respectively. The trypanocidal action of the ionophore was shown to be the result of an influx of Na+ resulting in an increased intracellular Na+ concentration followed by cell swelling. This mode of action differs from the mechanism for the anti-cancer activity of salinomycin reported to be by induction of apoptosis. Conclusion Here we have shown that salinomycin is an effective agent against bloodstream forms of T. brucei and might be a potential candidate for treatment of African trypanosomiasis.
Collapse
Affiliation(s)
- Dietmar Steverding
- BioMedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK.
| | | |
Collapse
|
23
|
Livak KJ, Wills QF, Tipping AJ, Datta K, Mittal R, Goldson AJ, Sexton DW, Holmes CC. Methods for qPCR gene expression profiling applied to 1440 lymphoblastoid single cells. Methods 2013; 59:71-9. [PMID: 23079396 PMCID: PMC3562442 DOI: 10.1016/j.ymeth.2012.10.004] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [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: 07/31/2012] [Revised: 09/18/2012] [Accepted: 10/05/2012] [Indexed: 01/10/2023] Open
Abstract
The stochastic nature of generating eukaryotic transcripts challenges conventional methods for obtaining and analyzing single-cell gene expression data. In order to address the inherent noise, detailed methods are described on how to collect data on multiple genes in a large number of single cells using microfluidic arrays. As part of a study exploring the effect of genotype on Wnt pathway activation, data were collected for 96 qPCR assays on 1440 lymphoblastoid cells. The description of methods includes preliminary data processing steps. The methods used in the collection and analysis of single-cell qPCR data are contrasted with those used in conventional qPCR.
Collapse
Affiliation(s)
- Kenneth J. Livak
- Fluidigm Corporation, 7000 Shoreline Court, Suite 100, South San Francisco, CA 94080, USA
| | - Quin F. Wills
- Department of Statistics, University of Oxford, Oxford OX1 3TG, United Kingdom
| | - Alex J. Tipping
- Stem Cell Laboratory, UCL Cancer Institute, University College London, London WC1E 6BT, United Kingdom
| | - Krishnalekha Datta
- Fluidigm Corporation, 7000 Shoreline Court, Suite 100, South San Francisco, CA 94080, USA
| | - Rowena Mittal
- Fluidigm Corporation, 7000 Shoreline Court, Suite 100, South San Francisco, CA 94080, USA
| | - Andrew J. Goldson
- UEA Flow Cytometry Services, BioMedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Darren W. Sexton
- BioMedical Research Centre, Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Chris C. Holmes
- Department of Statistics, University of Oxford, Oxford OX1 3TG, United Kingdom
| |
Collapse
|
24
|
Greatorex JS, Page RF, Curran MD, Digard P, Enstone JE, Wreghitt T, Powell PP, Sexton DW, Vivancos R, Nguyen-Van-Tam JS. Effectiveness of common household cleaning agents in reducing the viability of human influenza A/H1N1. PLoS One 2010; 5:e8987. [PMID: 20126543 PMCID: PMC2813869 DOI: 10.1371/journal.pone.0008987] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 01/12/2010] [Indexed: 12/03/2022] Open
Abstract
Background In the event of an influenza pandemic, the majority of people infected will be nursed at home. It is therefore important to determine simple methods for limiting the spread of the virus within the home. The purpose of this work was to test a representative range of common household cleaning agents for their effectiveness at killing or reducing the viability of influenza A virus. Methodology/Principal Findings Plaque assays provided a robust and reproducible method for determining virus viability after disinfection, while a National Standard influenza virus RT-PCR assay (VSOP 25, www.hpa-standardmethods.org.uk) was adapted to detect viral genome, and a British Standard (BS:EN 14476:2005) was modified to determine virus killing. Conclusions/Significance Active ingredients in a number of the cleaning agents, wipes, and tissues tested were able to rapidly render influenza virus nonviable, as determined by plaque assay. Commercially available wipes with a claimed antiviral or antibacterial effect killed or reduced virus infectivity, while nonmicrobiocidal wipes and those containing only low concentrations (<5%) of surfactants showed lower anti-influenza activity. Importantly, however, our findings indicate that it is possible to use common, low-technology agents such as 1% bleach, 10% malt vinegar, or 0.01% washing-up liquid to rapidly and completely inactivate influenza virus. Thus, in the context of the ongoing pandemic, and especially in low-resource settings, the public does not need to source specialized cleaning products, but can rapidly disinfect potentially contaminated surfaces with agents readily available in most homes.
Collapse
Affiliation(s)
- Jane S Greatorex
- Health Protection Agency, Addenbrookes Hospital, Cambridge, United Kingdom
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
The CLCA proteins were first shown to exist in bovine trachea and named as chloride channels calcium activated (CLCA) due to the calcium-dependent chloride conductance that appeared to be activated on expression of these proteins in trachea and other secretory epithelial cells. Since their initial discovery the CLCA gene family has grown extensively and family members have been identified in bovine, human, murine, equine and porcine tissues. The CLCA proteins appear to have a role to play in chloride conductance across epithelial cells and hence epithelial fluid secretion; cell-cell adhesion, apoptosis, cell cycle control and tumorgenesis and metastasis; mucous production and cell signalling in respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). There are four human homologues; hCLCA1, hCLCA2, hCLCA3 and hCLCA4. Interest in these proteins has gathered pace with the description of hCLCA1's involvement in several human respiratory diseases. This review will describe the CLCA gene family and then move on to look at the growing body of evidence that suggests that at least hCLCA1 has an important role in the pathogenesis of respiratory disease such as asthma, COPD and cystic fibrosis (CF).
Collapse
Affiliation(s)
- John P Winpenny
- The Airway Inflammation Research Group, Biomedical Research Centre, School of Medicine, Health Policy and Practice, Faculty of Health, University of East Anglia, Norwich, Norfolk NR47TJ, UK.
| | | | | |
Collapse
|
26
|
Steverding D, Wang X, Sexton DW. The trypanocidal effect of NO-releasing agents is not due to inhibition of the major cysteine proteinase in Trypanosoma brucei. Parasitol Res 2009; 105:1333-8. [DOI: 10.1007/s00436-009-1559-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 07/01/2009] [Indexed: 10/20/2022]
|
27
|
|
28
|
Abstract
The inappropriate accumulation of eosinophils and the subsequent release of their potent pro-inflammatory mediator arsenal are thought to be important contributors to the pathogenesis of asthma and other allergic diseases. It is also becoming apparent that eosinophils may play a role in the orchestration of immune responses in the asthmatic lung. There is therefore much interest in the development of strategies to limit or prevent eosinophil-induced toxicity. The mechanisms by which eosinophils accumulate in the peribronchial tissues of the lung are complex and include enhanced differentiation and release from the bone marrow, selective adhesion and transendothelial migration, directed movement in response to specific chemotactic mediators and finally prolonged survival as a consequence of delayed apoptosis. Thus it can be appreciated that there are many points at which the toxicity of eosinophils can be limited or even prevented. Important areas for potential advances in glucocorticoid (GC) development include efforts to dissociate their anti-inflammatory effects from unwanted side effects. Other areas include the development of humanized monoclonal antibodies against IL-4, IL-13 and IL-5 together with the inhibition of adhesion pathways and/or chemokines responsible for eosinophil accumulation in the asthmatic lung. Several avenues of research are currently underway in an attempt to define mechanisms by which pro-inflammatory cells such as eosinophils can be safely removed from the asthmatic lung through apoptosis induction and their subsequent ingestion by phagocytes. This review will discuss both the potential and shortcomings of these diverse approaches to limit eosinophil toxicity in the asthmatic lung.
Collapse
Affiliation(s)
- G M Walsh
- Allergic and Asthmatic Inflammation Group, School of Medicine, University of Aberdeen, Scotland, UK.
| | | | | | | | | | | |
Collapse
|
29
|
Abstract
BACKGROUND We have previously demonstrated that human bronchial epithelial cells engulf apoptotic eosinophils. OBJECTIVES To compare and contrast the phagocytic capabilities of monocyte-derived macrophage and primary airway epithelial cells for apoptotic granulocytes. RESULTS Here we compared phagocytosis of human apoptotic eosinophils and neutrophils by small and large airway epithelial cells (SAEC and LAEC) and monocyte-derived macrophages. Confocal microscopy of F-actin staining and scanning and transmission electron microscopy revealed phagocytic cup formation around apoptotic eosinophils by airway epithelial cells (AEC) membranes with evidence of their digestion. Resting and cytokine-stimulated AEC did not recognize and ingest apoptotic neutrophils. The latter were phagocytosed by macrophages that exhibited greater ingestion of and higher capacity for, apoptotic eosinophils over apoptotic neutrophils. Cytochalasin D completely abolished uptake of apoptotic eosinophils by SAEC, LAEC or macrophage monolayers. Ligation of epithelial cell CD44 receptors for 24 h increased phagocytosis of apoptotic eosinophils by SAEC and LAEC with a potency comparable with that of IL-1. Phagocytosis was a specific receptor-mediated process involving integrin- (alphavbeta3, alphavbeta5, CD36), phosphatidylserine receptor- and lectin-dependent mechanisms. No significant differences were observed in avarice for apoptotic eosinophils by SAEC or LAEC either resting, CD44 monoclonal antibodies- or cytokine- stimulated, or in their usage and expression of recognition receptors. CONCLUSION These findings further suggest and define an important role for the bronchial epithelium in the selective removal of apoptotic eosinophils from the airways in asthma.
Collapse
Affiliation(s)
- D W Sexton
- Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
| | | | | | | |
Collapse
|
30
|
Al-Rabia MW, Blaylock MG, Sexton DW, Walsh GM. Membrane receptor-mediated apoptosis and caspase activation in the differentiated EoL-1 eosinophilic cell line. J Leukoc Biol 2004; 75:1045-55. [PMID: 15075347 DOI: 10.1189/jlb.0803404] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Caspases are key molecules in the control of apoptosis, but relatively little is known about their contribution to eosinophil apoptosis. We examined caspase-3, -8, and -9 activities in receptor ligation-dependent apoptosis induction in the differentiated human eosinophilic cell line EoL-1. Differentiated EoL-1 exhibited bi-lobed nuclei, eosinophil-associated membrane receptors, and basic granule proteins. Annexin-V fluorescein isothiocyanate binding to EoL-1 revealed significant (P<0.01) apoptosis induction in cells cultured for 20 h with monoclonal antibodies (mAb) specific for CD45 (71%+/-4.3), CD45RA (58%+/-2.3), CD45RB (68%+/-2.4), CD95 (47%+/-2.6), and CD69 (52%+/-2.1) compared with control (23%+/-1.6) or CD45RO mAb (27%+/-3.9). The pan-caspase inhibitor Z-Val-Ala-Asp-fluoromethylketone (fmk) and inhibitors of caspase-8 (Z-Ile-Glu-Thr-Asp-fmk) and caspase-9 (Z-Leu-Glu-His-Asp-fmk) significantly inhibited mAb-induced apoptosis of EoL-1 but had no effect on constitutive (baseline) apoptosis at 16 and 20 h. Caspase activity was analyzed using the novel CaspaTag trade mark technique and flow cytometry. EoL-1 treated with pan-CD45, CD45RA, CD45RB, and CD95 mAb exhibited caspase-3 and -9 activation at 12 h post-treatment, which increased at 16 and 20 h. Activated caspase-8 was detected 12 and 16 h after ligation with CD45, CD45RA, CD45RB, and CD95 mAb followed by a trend toward basal levels at 20 h. CD69 ligation resulted in caspase-3 activation, a modest but significant activation of caspase-8, and a loss in mitochondrial transmembrane potential but had no significant effect on activation of caspase-9. Thus, the intrinsic and extrinsic caspase pathways are involved in controlling receptor ligation-mediated apoptosis induction in human eosinophils, findings that may aid the development of a more targeted, anti-inflammatory therapy for asthma.
Collapse
Affiliation(s)
- Mohammed W Al-Rabia
- Department of Medicine and Therapeutics, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | | | | | | |
Collapse
|
31
|
Abstract
Anti-inflammatory therapy in asthma is reliant on corticosteroids, particularly in their inhaled form. However, steroids are rather non-specific in their actions and they also raise concerns regarding compliance and side-effect Issues. Furthermore, a small proportion of patients with asthma fail to respond to oral glucocorticoids even at high doses. This Article will review the role that steroids and membrane receptor ligation play in the induction of eosinophil apoptosis together with the mechanisms by which corticosteroids enhance the disposal of apoptotic eosinophils by both professional and non-professional phagocytes. Eosinophils are thought to be the major pro-inflammatory effector cell in asthma and their persistence in the airways is probably enhanced by the presence of several asthma-relevant cytokines that prolong eosinophil survival by inhibition of apoptosis (interleukin (IL)-3, IL-5, granulocyte-macrophage colony-stimulating factor, IL-9, IL-13, IL-15). In contrast, a number of signals have been described that accelerate apoptosis in human eosinophils including corticosteroids or ligation of membrane receptors (CD95, CD45, CD69). Thus, the load of lung eosinophils in asthmatic disease is likely to be related to a balance in the tIssue microenvironment between pro- and anti-apoptotic signals. Furthermore, removal of apoptotic eosinophils by phagocytosis by alveolar macrophages or bronchial epithelial cells in a specific receptor-mediated way is as important as the process of apoptosis induction. Corticosteroids enhance the recognition and engulfment of apoptotic eosinophils by macrophages or bronchial epithelial cells. Caspases are key intracellular molecules in the control of apoptosis and defects in caspase-induced apoptosis in eosinophils from steroid-resistant individuals may contribute to the molecular mechanisms underlying glucocorticoid insensitivity in these cells. These findings point the way to new and more targeted anti-inflammatory therapy for asthma and may provide important clues for the development of alternative therapies for glucocorticoid resistance.
Collapse
Affiliation(s)
- G M Walsh
- Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
| | | | | |
Collapse
|
32
|
Al-Rabia MW, Blaylock MG, Sexton DW, Thomson L, Walsh GM. Granule protein changes and membrane receptor phenotype in maturing human eosinophils cultured from CD34+ progenitors. Clin Exp Allergy 2003; 33:640-8. [PMID: 12752593 DOI: 10.1046/j.1365-2222.2003.01639.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [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: 11/20/2022]
Abstract
BACKGROUND Eosinophils are now recognized as major effector cells in allergic and asthmatic disease with a potent armoury of mediators whose release makes a major contribution to the inflammation underlying these conditions. OBJECTIVES The purpose of this study was to compare cultured eosinophils (CE) with normal-density peripheral blood eosinophils (PBE) in terms of their membrane receptor expression and to analyse the expression and storage of the eosinophil granule proteins major basic protein (MBP) and eosinophil cationic protein (ECP) during eosinophil maturation in vitro. METHODS Purified human peripheral blood CD34+ cells were cultured in the presence of recombinant human IL-3, IL-5, rhGM-CSF, SCF, and FLT-3 ligand. PBE were isolated by density gradient centrifugation and negative immunomagnetic selection. Expression of CD11b, CD18, CD45, CD45RA, CD45RB, CD45RO, CD69, CD95, IL-5Ralpha, IL-9Ralpha, CCR1, CCR3, and CXCR4 by CE as they matured in culture were assessed by immunostaining and flow cytometry and expression of these receptors compared with freshly isolated PBE. Immunohistochemical staining and labophot-2TM light microscopy determined expression of MBP, ECP, and CD69 during eosinophil maturation. RESULTS Positive immunostaining for MBP and ECP was detectable in a proportion (15-20%) of CE as early as 3 days of culture even though these cells were mononuclear in appearance. The numbers of CE positive for both granule proteins increased in rhIL-3 and rhIL-5 treated cells to a maximum of approximately 80% by day 28. Maturing eosinophils exhibited positive immunostaining for CD69 after 14, 21 and 28 days of culture. Compared with PBE, CE had lower expression of pan-CD45 and CD45 isoforms, CD95 and CD11b. In contrast, the specific mean fluorescence for CD69, CD18, IL-5Ralpha, and IL-9Ralpha was significantly elevated for CE compared with PBE. CCR3 expression by CE and PBE was similar with no expression of CXCR4 detected by either CE or PBE. No significant difference in expression of CCR1 was found between CE and PBE. CONCLUSION These data suggest that CE and PBE share many phenotypic properties and both MBP and ECP appear early in eosinophil development in vitro. However, there are quantitative differences that may be a consequence of their immaturity and/or the influence of the cytokines used in their culture.
Collapse
Affiliation(s)
- M W Al-Rabia
- Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK.
| | | | | | | | | |
Collapse
|
33
|
Thomson L, Blaylock MG, Sexton DW, Campbell A, Walsh GM. Cetirizine and levocetirizine inhibit eotaxin-induced eosinophil transendothelial migration through human dermal or lung microvascular endothelial cells. Clin Exp Allergy 2002; 32:1187-92. [PMID: 12190657 DOI: 10.1046/j.1365-2745.2002.01444.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [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: 11/20/2022]
Abstract
BACKGROUND Several second-generation antihistamines have documented anti-inflammatory effects which appear independent of H1-receptor blockade. We investigated the inhibitory effect of cetirizine and its active enantiomer levocetirizine on eosinophil transendothelial migration (TEM) through monolayers of normal human dermal microvascular endothelial cells (HMVEC-d) or human lung microvascular endothelial cells (HMVEC-l). METHODS HMVEC-d or HMVEC-l were grown to confluence on micropore filters in transwells inserted into a 24-well tissue culture dish. Eosinophils were isolated by density gradient centrifugation and negative immunomagnetic selection. Untreated eosinophils or eosinophils pre-incubated (30 min at 37 degrees C) with a concentration range of cetirizine or levocetirizine (10-5 to 10-9 m) were added to the upper chamber of the transwell which was incubated for 60 min at 37 degrees C. Both spontaneous eosinophil TEM and TEM to 100 ng/mL of human eotaxin in the lower chamber were assessed. RESULTS Between 8 and 10% of the eosinophils added to the upper chamber underwent spontaneous TEM through HMVEC-d or HMVEC-l. The addition of eotaxin to the lower chamber enhanced eosinophil TEM through HMVEC-d or HMVEC-l monolayers to over 20%, i.e. an enhanced TEM of approximately 100% in each case. Pre-incubation of eosinophils with cetirizine or levocetirizine dose-dependently inhibited eosinophil TEM to eotaxin through both HMVEC-d or HMVEC-l with total inhibition of eotaxin-induced TEM observed at 10-8 m for HMVEC-d and 10-7 m for HMVEC-l. Both drugs gave a reduced but significant inhibition of eosinophil TEM at lower concentrations. No concentration of cetirizine or levocetirizine had any significant effect on expression of CD11b, CD18 or CD49d by either resting or eotaxin-stimulated eosinophils. Furthermore, no effect on spontaneous eosinophil TEM, or eosinophil viability was seen with any concentration of cetirizine or levocetirizine. CONCLUSION Levocetirizine inhibits eotaxin-induced eosinophil TEM through both dermal and lung microvascular endothelial cells suggesting that, like cetirizine, levocetirizine has potential anti-inflammatory effects.
Collapse
Affiliation(s)
- L Thomson
- Department of Medicine & Therapeutics, University of Aberdeen Medical School, Aberdeen, UK
| | | | | | | | | |
Collapse
|
34
|
|
35
|
Sexton DW, Blaylock MG, Walsh GM. Human alveolar epithelial cells engulf apoptotic eosinophils by means of integrin- and phosphatidylserine receptor-dependent mechanisms: a process upregulated by dexamethasone. J Allergy Clin Immunol 2001; 108:962-9. [PMID: 11742274 DOI: 10.1067/mai.2001.119414] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [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]
Abstract
BACKGROUND We previously demonstrated receptor-mediated apoptotic-eosinophil engulfment by human small airway epithelial cells, which may represent a potentially important mechanism in the resolution of allergic and asthmatic inflammation. OBJECTIVE A549 cells were selected as being representative of alveolar epithelial cells, and their ability to ingest human apoptotic eosinophils was examined in terms of the effects of dexamethasone treatment and the receptor-mediated recognition mechanisms important in this process. METHODS A549 epithelial-cell expression of alpha(v)beta3, alpha(v)beta5, CD36, and the phosphatidylserine receptor was established by using immunostaining and flow cytometry, and inhibition assays were examined by using the role of these receptors in apoptotic-eosinophil recognition by resting and dexamethasone-treated A549 epithelial cells. Electron microscopy confirmed engulfment of apoptotic eosinophils, and receptor clustering around apoptotic eosinophils was examined by using immunofluorescent labeling. RESULTS A549 epithelial cells recognized and engulfed apoptotic eosinophils but not freshly isolated cells. Dexamethasone enhanced the number of A549 cells ingesting apoptotic eosinophils and dose dependently increased their capacity for ingestion. The tetrapeptide RGDS significantly inhibited apoptotic-eosinophil uptake by A549 cells, indicating a role for integrins in the recognition process. A549 cells expressed alpha(v)beta3, alpha(v)beta5, beta5, CD36, and the phosphatidylserine receptor, and expression of these receptors was not significantly increased after dexamethasone treatment. Engulfment of apoptotic eosinophils by A549 cells involved alpha(v)beta3-, CD36-, alpha(v)beta5-, and phosphatidylserine receptor-mediated recognition mechanisms and was associated with the formation of integrin focal adhesion complexes around apoptotic eosinophils. CONCLUSIONS These data further suggest a nonpassive role for airway epithelium in the resolution of eosinophilic inflammation in asthma.
Collapse
Affiliation(s)
- D W Sexton
- Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | | | | |
Collapse
|
36
|
Blaylock MG, Sexton DW, Walsh GM. Ligation of CD45 and the isoforms CD45RA and CD45RB accelerates the rate of constitutive apoptosis in human eosinophils. J Allergy Clin Immunol 1999; 104:1244-50. [PMID: 10589008 DOI: 10.1016/s0091-6749(99)70020-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Eosinophils are important effector cells in asthma pathogenesis, and an understanding of the mechanisms involved in eosinophil apoptosis induction might thus be relevant to the resolution of asthmatic inflammation. OBJECTIVE Our aim was to determine the role of the common leukocyte antigen CD45 and the isoforms CD45RA, CD45RB, and CD45RO in human eosinophil apoptosis induction. METHODS Immmunostaining and flow cytometry were used to assess CD45 and CD45 isoform expression by eosinophils purified with use of density gradients and immunomagnetic negative selection. Apoptosis induction was measured by binding of fluorescein isothiocyanate-labeled annexin V to eosinophils cultured for 20 hours alone or with saturating quantities of mAb against CD45, CD45RA, CD45RB, CD45RO, CD9, CD11b, and isotype-matched controls in the presence or absence of GM-CSF. RESULTS Freshly isolated eosinophils had high expression of CD45 and CD45RO, modest expression of CD45RB, and low expression of CD45RA. Eosinophils cultured alone for 20 hours were found to be approximately 20% to 25% apoptotic. Incubation with mAb against CD45, CD45RA, and CD45RB resulted in significant (P <.005) enhancement (>100%) of their constitutive rate of apoptosis. Incubation with CD45RO, CD11b, CD9 mAb, or isotype controls had no significant effect on the rate of eosinophil constitutive apoptosis. The addition of GM-CSF inhibited eosinophil apoptosis but did not prevent CD45, CD45RA, or CD45RB mAb-dependent apoptosis induction. CONCLUSION These data indicate that ligation of CD45, CD45RA, or CD45RB represents a novel pathway for the induction of apoptosis in human eosinophils.
Collapse
Affiliation(s)
- M G Blaylock
- Department of Medicine and Therapeutics, University of Aberdeen Medical School, Aberdeen, United Kingdom
| | | | | |
Collapse
|
37
|
Walsh GM, Sexton DW, Blaylock MG, Convery CM. Resting and cytokine-stimulated human small airway epithelial cells recognize and engulf apoptotic eosinophils. Blood 1999; 94:2827-35. [PMID: 10515886] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Eosinophils, which are prominent cells in asthmatic inflammation, undergo apoptosis and are recognized and engulfed by phagocytic macrophages in vitro. We have examined the ability of human small airway epithelial cells (SAEC) to recognize and ingest apoptotic human eosinophils. Cultured SAEC ingested apoptotic eosinophils but not freshly isolated eosinophils or opsonized erythrocytes. The ability of SAEC to ingest apoptotic eosinophils was enhanced by interleukin-1alpha (IL-1alpha) or tumor necrosis factor alpha (TNFalpha) in a time- and concentration-dependent fashion. IL-1alpha was found to be more potent than TNFalpha and each was optimal at 10(-10) mol/L, with a significant (P <.05) effect observed at 1 hour postcytokine incubation that was maximal at 5 hours. IL-1alpha stimulation not only increased the number of SAEC engulfing apoptotic eosinophils, but also enhanced their capacity for ingestion. The amino sugars glucosamine, n-acetyl glucosamine, and galactosamine significantly inhibited uptake of apoptotic eosinophils by both resting and IL-1alpha-stimulated SAEC, in contrast to the parent sugars glucose, galactose, mannose, and fucose. Incubation of apoptotic eosinophils with the tetrapeptide RGDS, but not RGES, significantly inhibited their uptake by both resting and IL-1alpha-stimulated SAEC, as did monoclonal antibody against alphavbeta3 and CD36. Thus, SAEC recognize apoptotic eosinophils via lectin- and integrin-dependent mechanisms. These data demonstrate a novel function for human bronchial epithelial cells that might represent an important mechanism in the resolution of eosinophil-induced asthmatic inflammation.
Collapse
Affiliation(s)
- G M Walsh
- Department of Medicine & Therapeutics, University of Aberdeen Medical School, Aberdeen, UK.
| | | | | | | |
Collapse
|