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Major G, Longoni A, Simcock J, Magon NJ, Harte J, Bathish B, Kemp R, Woodfield T, Lim KS. Clinical Applicability of Visible Light-Mediated Cross-linking for Structural Soft Tissue Reconstruction. Adv Sci (Weinh) 2023; 10:e2300538. [PMID: 37424046 PMCID: PMC10502829 DOI: 10.1002/advs.202300538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 05/28/2023] [Indexed: 07/11/2023]
Abstract
Visible light-mediated cross-linking has utility for enhancing the structural capacity and shape fidelity of laboratory-based polymers. With increased light penetration and cross-linking speed, there is opportunity to extend future applications into clinical spheres. This study evaluated the utility of a ruthenium/sodium persulfate photocross-linking system for increasing structural control in heterogeneous living tissues as an example, focusing on unmodified patient-derived lipoaspirate for soft tissue reconstruction. Freshly-isolated tissue is photocross-linked, then the molar abundance of dityrosine bonds is measured using liquid chromatography tandem mass spectrometry and the resulting structural integrity assessed. The cell function and tissue survival of photocross-linked grafts is evaluated ex vivo and in vivo, with tissue integration and vascularization assessed using histology and microcomputed tomography. The photocross-linking strategy is tailorable, allowing progressive increases in the structural fidelity of lipoaspirate, as measured by a stepwise reduction in fiber diameter, increased graft porosity and reduced variation in graft resorption. There is an increase in dityrosine bond formation with increasing photoinitiator concentration, and tissue homeostasis is achieved ex vivo, with vascular cell infiltration and vessel formation in vivo. These data demonstrate the capability and applicability of photocrosslinking strategies for improving structural control in clinically-relevant settings, potentially achieving more desirable patient outcomes using minimal manipulation in surgical procedures.
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Affiliation(s)
- Gretel Major
- Department of Orthopaedic Surgery and Musculoskeletal MedicineCentre for Bioengineering & NanomedicineUniversity of OtagoChristchurch8011New Zealand
| | - Alessia Longoni
- Department of Orthopaedic Surgery and Musculoskeletal MedicineCentre for Bioengineering & NanomedicineUniversity of OtagoChristchurch8011New Zealand
| | - Jeremy Simcock
- Department of SurgeryUniversity of OtagoChristchurch8011New Zealand
| | - Nicholas J Magon
- Centre for Free Radical ResearchDepartment of Pathology and Biomedical ScienceUniversity of OtagoChristchurch8011New Zealand
| | - Jessica Harte
- Jacqui Wood Cancer CentreDivision of Cellular MedicineNinewells Hospital and Medical SchoolUniversity of DundeeDundeeScotlandDD2 1GZUK
| | - Boushra Bathish
- Department of Orthopaedic Surgery and Musculoskeletal MedicineCentre for Bioengineering & NanomedicineUniversity of OtagoChristchurch8011New Zealand
- Jacqui Wood Cancer CentreDivision of Cellular MedicineNinewells Hospital and Medical SchoolUniversity of DundeeDundeeScotlandDD2 1GZUK
| | - Roslyn Kemp
- Department of Microbiology and ImmunologyUniversity of OtagoDunedin9016New Zealand
| | - Tim Woodfield
- Department of Orthopaedic Surgery and Musculoskeletal MedicineCentre for Bioengineering & NanomedicineUniversity of OtagoChristchurch8011New Zealand
| | - Khoon S Lim
- Department of Orthopaedic Surgery and Musculoskeletal MedicineCentre for Bioengineering & NanomedicineUniversity of OtagoChristchurch8011New Zealand
- Light‐Activated Biomaterials GroupSchool of Medical SciencesUniversity of SydneySydney2006Australia
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Bozonet SM, Magon NJ, Schwartfeger AJ, Konigstorfer A, Heath SG, Vissers MCM, Morris VK, Göbl C, Murphy JM, Salvesen GS, Hampton MB. Oxidation of caspase-8 by hypothiocyanous acid enables TNF-mediated necroptosis. J Biol Chem 2023:104792. [PMID: 37150321 DOI: 10.1016/j.jbc.2023.104792] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/09/2023] Open
Abstract
Necroptosis is a form of regulated cell death triggered by various host and pathogen-derived molecules during infection and inflammation. The essential step leading to necroptosis is phosphorylation of the mixed lineage kinase domain-like protein (MLKL) by receptor-interacting protein kinase 3 (RIPK3). Caspase 8 cleaves RIPKs to block necroptosis, so synthetic caspase inhibitors are required to study this process in experimental models. However, it is unclear how caspase-8 activity is regulated in a physiological setting. The active site cysteine of caspases is sensitive to oxidative inactivation, so we hypothesized that oxidants generated at sites of inflammation can inhibit caspase-8 and promote necroptosis. Here, we discovered that hypothiocyanous acid (HOSCN), an oxidant generated in vivo by heme peroxidases including myeloperoxidase and lactoperoxidase, is a potent caspase-8 inhibitor. We found HOSCN was able to promote necroptosis in mouse fibroblasts treated with tumor necrosis factor (TNF). We also demonstrate purified caspase-8 was inactivated by low concentrations of HOSCN, with the predominant product being a disulfide-linked dimer between Cys360 and Cys409 of the large and small catalytic subunits. We show oxidation still occurred in the presence of reducing agents, and reduction of the dimer was slow, consistent with HOSCN being a powerful physiological caspase inhibitor. While the initial oxidation product is a dimer, further modification also occurred in cells treated with HOSCN, leading to higher molecular weight caspase-8 species. Taken together, these findings indicate major disruption of caspase-8 function, and suggest a novel mechanism for the promotion of necroptosis at sites of inflammation.
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Affiliation(s)
- S M Bozonet
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - N J Magon
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - A J Schwartfeger
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - A Konigstorfer
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - S G Heath
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - M C M Vissers
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - V K Morris
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - C Göbl
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand; School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - J M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - G S Salvesen
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - M B Hampton
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.
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Crake RLI, Burgess ER, Wiggins GAR, Magon NJ, Das AB, Vissers MCM, Morrin HR, Royds JA, Slatter TL, Robinson BA, Phillips E, Dachs GU. P12.06.A Relationship between ascorbate and DNA methylation markers in clinical glioma tumours. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.271] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Members of the 2-oxoglutarate-dependent dioxygenase (OGDD) enzyme family play an important role in gliomas as they regulate epigenetic modifications and response to hypoxia. The OGDDs require 2-OG and O2 as substrates, and ferrous iron and ascorbate as cofactors. Both hypoxia and aberrant DNA methylation are prognostic indicators for gliomas. The ten-eleven translocase (TET) DNA demethylases are OGDDs that convert 5-methyl cytosine (5mC) to 5-hydroxymethylcytosine (5hmC), with 5hmC levels related to better prognosis. Despite this, there is limited data on the OGDD enzymes and their substrates/cofactors in glioma tissues. Our previous study showed an association between ascorbate content and markers of the hypoxic response in glioblastoma tissue. Here we determine whether there is an association between ascorbate and DNA methylation in glioma. In addition, we assess whether methylation of the methylguanine-DNA methyltransferase (DNA repair enzyme MGMT) promoter is associated with ascorbate content.
Materials and methods
Frozen clinical glioma samples from 37 patients (n=11 WHO grade I-III, n=26 glioblastoma) were obtained from the Cancer Society Tissue Bank (Ethics approval H19/163). Isocitrate dehydrogenase 1 (IDH1) mutation status was determined by sequencing. Samples were processed on dry ice in liquid nitrogen and analysed for ascorbate (high-performance liquid chromatography), global DNA methylation (mass spectrometry) and MGMT promoter analyses (methylation specific PCR).
Results
Many grade I-III tumours were IDH1 R132H mutant (6/11), and most glioblastomas were not (2/26). Glioblastoma had significantly lower ascorbate content than grade I-III tumours (p=0.026). Glioblastoma also had lower global 5hmC levels (p=0.0013). IDH1 R132H tumours tended to have a lower ascorbate content (p=0.09). Ascorbate and 5hmC levels were directly correlated (Spearman r= 0.466, p=0.004). However, cytosine and 5mC showed no association with grade or ascorbate. MGMT promoter methylation status was not associated with global methylation or ascorbate content (p=0.97, p=0.96, respectively).
Conclusion
Our data suggests that ascorbate supports TET activity in clinical glioma. It also appears that site-specific (promoter) methylation was not affected by ascorbate availability. These findings may have clinical implications, as higher 5hmC levels are associated with improved outcome, whilst continued MGMT suppression suggests chemotherapy responsiveness. However, evidence that raising tumour ascorbate leads to increased 5hmC levels, or an associated improvement in survival, requires intervention trials.
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Affiliation(s)
| | - E R Burgess
- University of Otago Christchurch , Christchurch , New Zealand
| | - G A R Wiggins
- University of Otago Christchurch , Christchurch , New Zealand
| | - N J Magon
- University of Otago Christchurch , Christchurch , New Zealand
| | - A B Das
- Peter MacCallum Cancer Centre , Melbourne , Australia
| | - M C M Vissers
- University of Otago Christchurch , Christchurch , New Zealand
| | - H R Morrin
- University of Otago Christchurch , Christchurch , New Zealand
| | - J A Royds
- University of Otago , Dunedin , New Zealand
| | | | - B A Robinson
- Canterbury District Health Board , Christchurch , New Zealand
| | - E Phillips
- University of Otago Christchurch , Christchurch , New Zealand
| | - G U Dachs
- University of Otago Christchurch , Christchurch , New Zealand
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Smyth LCD, Murray HC, Hill M, van Leeuwen E, Highet B, Magon NJ, Osanlouy M, Mathiesen SN, Mockett B, Singh-Bains MK, Morris VK, Clarkson AN, Curtis MA, Abraham WC, Hughes SM, Faull RLM, Kettle AJ, Dragunow M, Hampton MB. Neutrophil-vascular interactions drive myeloperoxidase accumulation in the brain in Alzheimer's disease. Acta Neuropathol Commun 2022; 10:38. [PMID: 35331340 PMCID: PMC8944147 DOI: 10.1186/s40478-022-01347-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/11/2022] [Indexed: 01/13/2023] Open
Abstract
INTRODUCTION Neutrophil accumulation is a well-established feature of Alzheimer's disease (AD) and has been linked to cognitive impairment by modulating disease-relevant neuroinflammatory and vascular pathways. Neutrophils express high levels of the oxidant-generating enzyme myeloperoxidase (MPO), however there has been controversy regarding the cellular source and localisation of MPO in the AD brain. MATERIALS AND METHODS We used immunostaining and immunoassays to quantify the accumulation of neutrophils in human AD tissue microarrays and in the brains of APP/PS1 mice. We also used multiplexed immunolabelling to define the presence of NETs in AD. RESULTS There was an increase in neutrophils in AD brains as well as in the murine APP/PS1 model of AD. Indeed, MPO expression was almost exclusively confined to S100A8-positive neutrophils in both human AD and murine APP/PS1 brains. The vascular localisation of neutrophils in both human AD and mouse models of AD was striking and driven by enhanced neutrophil adhesion to small vessels. We also observed rare infiltrating neutrophils and deposits of MPO around plaques. Citrullinated histone H3, a marker of neutrophil extracellular traps (NETs), was also detected in human AD cases at these sites, indicating the presence of extracellular MPO in the vasculature. Finally, there was a reduction in the endothelial glycocalyx in AD that may be responsible for non-productive neutrophil adhesion to the vasculature. CONCLUSION Our report indicates that vascular changes may drive neutrophil adhesion and NETosis, and that neutrophil-derived MPO may lead to vascular oxidative stress and be a relevant therapeutic target in AD.
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Affiliation(s)
- Leon C. D. Smyth
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
- Department of Pathology and Immunology, Center for Brain Immunology and Glia, Washington University in St. Louis, Campus, Box 8118, St. Louis, MO USA
| | - Helen C. Murray
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Madison Hill
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Eve van Leeuwen
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Blake Highet
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Nicholas J. Magon
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Mahyar Osanlouy
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Sophie N. Mathiesen
- Department of Psychology, University of Otago, Dunedin, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Bruce Mockett
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Malvindar K. Singh-Bains
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Vanessa K. Morris
- School of Biological Science, University of Canterbury, Canterbury, New Zealand
| | | | - Maurice A. Curtis
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | | | | | - Richard L. M. Faull
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Anthony J. Kettle
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Mike Dragunow
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Mark B. Hampton
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
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5
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Edwards TS, Dickerhof N, Magon NJ, Paton LN, Sly PD, Kettle AJ. Formation of Calprotectin-Derived Peptides in the Airways of Children with Cystic Fibrosis. J Immunol 2022; 208:979-990. [PMID: 35046105 DOI: 10.4049/jimmunol.2001017] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Calprotectin is released by activated neutrophils along with myeloperoxidase (MPO) and proteases. It plays numerous roles in inflammation and infection, and is used as an inflammatory biomarker. However, calprotectin is readily oxidized by MPO-derived hypohalous acids to form covalent dimers of its S100A8 and S100A9 subunits. The dimers are susceptible to degradation by proteases. We show that detection of human calprotectin by ELISA declines markedly because of its oxidation by hypochlorous acid and subsequent degradation. Also, proteolysis liberates specific peptides from oxidized calprotectin that is present at inflammatory sites. We identified six calprotectin-derived peptides by mass spectrometry and detected them in the bronchoalveolar lavage fluid of children with cystic fibrosis (CF). We assessed the peptides as biomarkers of neutrophilic inflammation and infection. The content of the calprotectin peptide ILVI was related to calprotectin (r = 0.72, p = 0.01, n = 10). Four of the peptides were correlated with the concentration of MPO (r > 0.7, p ≤ 0.01, n = 21), while three were higher (p < 0.05) in neutrophil elastase-positive (n = 14) than -negative samples (n = 7). Also, five of the peptides were higher (p < 0.05) in the bronchoalveolar lavage fluid from children with CF with infections (n = 21) than from non-CF children without infections (n = 6). The specific peptides liberated from calprotectin will signal uncontrolled activity of proteases and MPO during inflammation. They may prove useful in tracking inflammation in respiratory diseases dominated by neutrophils, including coronavirus disease 2019.
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Affiliation(s)
- Teagan S Edwards
- Department of Paediatrics, University of Otago Christchurch, Christchurch, New Zealand;
| | - Nina Dickerhof
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand; and
| | - Nicholas J Magon
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand; and
| | - Louise N Paton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand; and
| | - Peter D Sly
- Child Health Research Centre, University of Queensland, Brisbane, Australia
| | - Anthony J Kettle
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand; and
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Paumann-Page M, Kienzl NF, Motwani J, Bathish B, Paton LN, Magon NJ, Sevcnikar B, Furtmüller PG, Traxlmayr MW, Obinger C, Eccles MR, Winterbourn CC. Peroxidasin protein expression and enzymatic activity in metastatic melanoma cell lines are associated with invasive potential. Redox Biol 2021; 46:102090. [PMID: 34438259 PMCID: PMC8390535 DOI: 10.1016/j.redox.2021.102090] [Citation(s) in RCA: 12] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 07/31/2021] [Indexed: 02/06/2023] Open
Abstract
Peroxidasin, a heme peroxidase, has been shown to play a role in cancer progression. mRNA expression has been reported to be upregulated in metastatic melanoma cell lines and connected to the invasive phenotype, but little is known about how peroxidasin acts in cancer cells. We have analyzed peroxidasin protein expression and activity in eight metastatic melanoma cell lines using an ELISA developed with an in-house peroxidasin binding protein. RNAseq data analysis confirmed high peroxidasin mRNA expression in the five cell lines classified as invasive and low expression in the three non-invasive cell lines. Protein levels of peroxidasin were higher in the cell lines with an invasive phenotype. Active peroxidasin was secreted to the cell culture medium, where it accumulated over time, and peroxidasin protein levels in the medium were also much higher in invasive than non-invasive cell lines. The only well-established physiological role of peroxidasin is in the formation of a sulfilimine bond, which cross-links collagen IV in basement membranes via catalyzed oxidation of bromide to hypobromous acid. We found that peroxidasin secreted from melanoma cells formed sulfilimine bonds in uncross-linked collagen IV, confirming peroxidasin activity and hypobromous acid formation. Moreover, 3-bromotyrosine, a stable product of hypobromous acid reacting with tyrosine residues, was detected in invasive melanoma cells, substantiating that their expression of peroxidasin generates hypobromous acid, and showing that it does not exclusively react with collagen IV, but also with other biomolecules.
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Affiliation(s)
- Martina Paumann-Page
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, P.O. Box 4345, Christchurch, New Zealand.
| | - Nikolaus F Kienzl
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Jyoti Motwani
- Department of Pathology, Dunedin School of Medicine, University of Otago, 270 Great King Street, Dunedin, 9054, New Zealand
| | - Boushra Bathish
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, P.O. Box 4345, Christchurch, New Zealand
| | - Louise N Paton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, P.O. Box 4345, Christchurch, New Zealand
| | - Nicholas J Magon
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, P.O. Box 4345, Christchurch, New Zealand
| | - Benjamin Sevcnikar
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Paul G Furtmüller
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Michael W Traxlmayr
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Christian Obinger
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria
| | - Mike R Eccles
- Department of Pathology, Dunedin School of Medicine, University of Otago, 270 Great King Street, Dunedin, 9054, New Zealand
| | - Christine C Winterbourn
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, P.O. Box 4345, Christchurch, New Zealand
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Smith-Díaz CC, Magon NJ, McKenzie JL, Hampton MB, Vissers MCM, Das AB. Ascorbate Inhibits Proliferation and Promotes Myeloid Differentiation in TP53-Mutant Leukemia. Front Oncol 2021; 11:709543. [PMID: 34497762 PMCID: PMC8419345 DOI: 10.3389/fonc.2021.709543] [Citation(s) in RCA: 12] [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: 05/14/2021] [Accepted: 08/02/2021] [Indexed: 11/26/2022] Open
Abstract
Loss-of-function mutations in the DNA demethylase TET2 are associated with the dysregulation of hematopoietic stem cell differentiation and arise in approximately 10% of de novo acute myeloid leukemia (AML). TET2 mutations coexist with other mutations in AML, including TP53 mutations, which can indicate a particularly poor prognosis. Ascorbate can function as an epigenetic therapeutic in pathological contexts involving heterozygous TET2 mutations by restoring TET2 activity. How this response is affected when myeloid leukemia cells harbor mutations in both TET2 and TP53 is unknown. Therefore, we examined the effects of ascorbate on the SKM-1 AML cell line that has mutated TET2 and TP53. Sustained treatment with ascorbate inhibited proliferation and promoted the differentiation of these cells. Furthermore, ascorbate treatment significantly increased 5-hydroxymethylcytosine, suggesting increased TET activity as the likely mechanism. We also investigated whether ascorbate affected the cytotoxicity of Prima-1Met, a drug that reactivates some p53 mutants and is currently in clinical trials for AML. We found that the addition of ascorbate had a minimal effect on Prima-1Met–induced cytotoxicity, with small increases or decreases in cytotoxicity being observed depending on the timing of treatment. Collectively, these data suggest that ascorbate could exert a beneficial anti-proliferative effect on AML cells harboring both TET2 and TP53 mutations whilst not interfering with targeted cytotoxic therapies such as Prima-1Met.
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Affiliation(s)
- Carlos C Smith-Díaz
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Nicholas J Magon
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Judith L McKenzie
- Haematology Research Group, Christchurch Hospital and Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Andrew B Das
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
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8
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Meng Y, Sheen CR, Magon NJ, Hampton MB, Dobson RCJ. Structure-function analyses of alkylhydroperoxidase D from Streptococcus pneumoniae reveal an unusual three-cysteine active site architecture. J Biol Chem 2020; 295:2984-2999. [PMID: 31974167 DOI: 10.1074/jbc.ra119.012226] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/19/2020] [Indexed: 12/12/2022] Open
Abstract
During aerobic growth, the Gram-positive facultative anaerobe and opportunistic human pathogen Streptococcus pneumoniae generates large amounts of hydrogen peroxide that can accumulate to millimolar concentrations. The mechanism by which this catalase-negative bacterium can withstand endogenous hydrogen peroxide is incompletely understood. The enzyme alkylhydroperoxidase D (AhpD) has been shown to contribute to pneumococcal virulence and oxidative stress responses in vivo We demonstrate here that SpAhpD exhibits weak thiol-dependent peroxidase activity and, unlike the previously reported Mycobacterium tuberculosis AhpC/D system, SpAhpD does not mediate electron transfer to SpAhpC. A 2.3-Å resolution crystal structure revealed several unusual structural features, including a three-cysteine active site architecture that is buried in a deep pocket, in contrast to the two-cysteine active site found in other AhpD enzymes. All single-cysteine SpAhpD variants remained partially active, and LC-MS/MS analyses revealed that the third cysteine, Cys-163, formed disulfide bonds with either of two cysteines in the canonical Cys-78-X-X-Cys-81 motif. We observed that SpAhpD formed a dimeric quaternary structure both in the crystal and in solution, and that the highly conserved Asn-76 of the AhpD core motif is important for SpAhpD folding. In summary, SpAhpD is a weak peroxidase and does not transfer electrons to AhpC, and therefore does not fit existing models of bacterial AhpD antioxidant defense mechanisms. We propose that it is unlikely that SpAhpD removes peroxides either directly or via AhpC, and that SpAhpD cysteine oxidation may act as a redox switch or mediate electron transfer with other thiol proteins.
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Affiliation(s)
- Yanxiang Meng
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch 8041, New Zealand
| | - Campbell R Sheen
- Callaghan Innovation, University of Canterbury, Christchurch 8041, New Zealand
| | - Nicholas J Magon
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand.
| | - Renwick C J Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch 8041, New Zealand; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia.
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9
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Abstract
This chapter describes three methods for measuring the bactericidal activity of neutrophils. All utilize colony counting techniques to quantify viable bacteria. A simple "one-step" protocol provides a composite measure of phagocytosis and killing, while a "two-step" protocol that separates extracellular and intracellular bacteria allows calculation of rate constants for both of these processes. We also present a method for selectively monitoring the long-term survival of bacteria within the phagosome. This may have application in identifying resistant strains and searching for compounds that sensitize pathogens to destruction.
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Affiliation(s)
- Nicholas J Magon
- Department of Pathology and Biomedical Science, Centre for Free Radical Research, University of Otago Christchurch, Christchurch, New Zealand
| | - Heather A Parker
- Department of Pathology and Biomedical Science, Centre for Free Radical Research, University of Otago Christchurch, Christchurch, New Zealand
| | - Louisa V Ashby
- Department of Pathology and Biomedical Science, Centre for Free Radical Research, University of Otago Christchurch, Christchurch, New Zealand
| | - Reuben J Springer
- Department of Pathology and Biomedical Science, Centre for Free Radical Research, University of Otago Christchurch, Christchurch, New Zealand
| | - Mark B Hampton
- Department of Pathology and Biomedical Science, Centre for Free Radical Research, University of Otago Christchurch, Christchurch, New Zealand.
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10
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Roch A, Magon NJ, Maire J, Suarna C, Ayer A, Waldvogel S, Imhof BA, Koury MJ, Stocker R, Schapira M. Transition to 37°C reveals importance of NADPH in mitigating oxidative stress in stored RBCs. JCI Insight 2019; 4:126376. [PMID: 31581149 DOI: 10.1172/jci.insight.126376] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 09/25/2019] [Indexed: 01/14/2023] Open
Abstract
The RBC storage lesion is a multiparametric response that occurs during storage at 4°C, but its impact on transfused patients remains unclear. In studies of the RBC storage lesion, the temperature transition from cold storage to normal body temperature that occurs during transfusion has received limited attention. We hypothesized that multiple deleterious events might occur in this period of increasing temperature. We show dramatic alterations in several properties of therapeutic blood units stored at 4°C after warming them to normal body temperature (37°C), as well as febrile temperature (40°C). In particular, the intracellular content and redox state of NADP(H) were directly affected by post-storage incubation at 37°C, as well as by pro-oxidant storage conditions. Modulation of the NADPH-producing pentose phosphate pathway, but not the prevention of hemoglobin autoxidation by conversion of oxyhemoglobin to carboxyhemoglobin, provided protection against storage-induced alterations in RBCs, demonstrating the central role of NADPH in mitigating increased susceptibility of stored RBCs to oxidative stress. We propose that assessing RBC oxidative status after restoration of body temperature constitutes a sensitive method for detecting storage-related alterations that has the potential to improve the quality of stored RBCs for transfusion.
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Affiliation(s)
- Aline Roch
- Department of Pathology and Immunology, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Nicholas J Magon
- Department of Pathology and Immunology, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Jessica Maire
- Department of Pathology and Immunology, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Cacang Suarna
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia
| | - Anita Ayer
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia.,St Vincent's Clinical School, University of New South Wales Medicine, Sydney, New South Wales, Australia
| | - Sophie Waldvogel
- Centre de Transfusion Sanguine, University Hospitals, University of Geneva, Geneva, Switzerland
| | - Beat A Imhof
- Department of Pathology and Immunology, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Mark J Koury
- Hematology/Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Roland Stocker
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia.,St Vincent's Clinical School, University of New South Wales Medicine, Sydney, New South Wales, Australia
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11
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Magon NJ, Turner R, Gearry RB, Hampton MB, Sly PD, Kettle AJ. Oxidation of calprotectin by hypochlorous acid prevents chelation of essential metal ions and allows bacterial growth: Relevance to infections in cystic fibrosis. Free Radic Biol Med 2015; 86:133-44. [PMID: 26006104 DOI: 10.1016/j.freeradbiomed.2015.05.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 11/16/2022]
Abstract
Calprotectin provides nutritional immunity by sequestering manganese and zinc ions. It is abundant in the lungs of patients with cystic fibrosis but fails to prevent their recurrent infections. Calprotectin is a major protein of neutrophils and composed of two monomers, S100A8 and S100A9. We show that the ability of calprotectin to limit growth of Staphylococcus aureus and Pseudomonas aeruginosa is exquisitely sensitive to oxidation by hypochlorous acid. The N-terminal cysteine residue on S100A9 was highly susceptible to oxidation which resulted in cross-linking of the protein monomers. The N-terminal methionine of S100A8 was also readily oxidized by hypochlorous acid, forming both the methionine sulfoxide and the unique product dehydromethionine. Isolated human neutrophils formed these modifications on calprotectin when their myeloperoxidase generated hypochlorous acid. Up to 90% of the N-terminal amine on S100A8 in bronchoalveolar lavage fluid from young children with cystic fibrosis was oxidized. Oxidized calprotectin was higher in children with cystic fibrosis compared to disease controls, and further elevated in those patients with infections. Our data suggest that oxidative stress associated with inflammation in cystic fibrosis will stop metal sequestration by calprotectin. Consequently, strategies aimed at blocking extracellular myeloperoxidase activity should enable calprotectin to provide nutritional immunity within the airways.
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Affiliation(s)
- Nicholas J Magon
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Rufus Turner
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Richard B Gearry
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Peter D Sly
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand; Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Anthony J Kettle
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand.
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12
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Wilkie-Grantham RP, Magon NJ, Harwood DT, Kettle AJ, Vissers MC, Winterbourn CC, Hampton MB. Myeloperoxidase-dependent lipid peroxidation promotes the oxidative modification of cytosolic proteins in phagocytic neutrophils. J Biol Chem 2015; 290:9896-905. [PMID: 25697357 DOI: 10.1074/jbc.m114.613422] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [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: 09/21/2014] [Indexed: 12/31/2022] Open
Abstract
Phagocytic neutrophils generate reactive oxygen species to kill microbes. Oxidant generation occurs within an intracellular phagosome, but diffusible species can react with the neutrophil and surrounding tissue. To investigate the extent of oxidative modification, we assessed the carbonylation of cytosolic proteins in phagocytic neutrophils. A 4-fold increase in protein carbonylation was measured within 15 min of initiating phagocytosis. Carbonylation was dependent on NADPH oxidase and myeloperoxidase activity and was inhibited by butylated hydroxytoluene and Trolox, indicating a role for myeloperoxidase-dependent lipid peroxidation. Proteomic analysis of target proteins revealed significant carbonylation of the S100A9 subunit of calprotectin, a truncated form of Hsp70, actin, and hemoglobin from contaminating erythrocytes. The addition of the reactive aldehyde 4-hydroxynonenal (HNE) caused carbonylation, and HNE-glutathione adducts were detected in the cytosol of phagocytic neutrophils. The post-translational modification of neutrophil proteins will influence the functioning and fate of these immune cells in the period following phagocytic activation, and provides a marker of neutrophil activation during infection and inflammation.
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Affiliation(s)
- Rachel P Wilkie-Grantham
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Nicholas J Magon
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - D Tim Harwood
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Anthony J Kettle
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Margreet C Vissers
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Christine C Winterbourn
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Mark B Hampton
- From the Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8140, New Zealand
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13
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Tidén AK, Sjögren T, Svensson M, Bernlind A, Senthilmohan R, Auchère F, Norman H, Markgren PO, Gustavsson S, Schmidt S, Lundquist S, Forbes LV, Magon NJ, Paton LN, Jameson GNL, Eriksson H, Kettle AJ. 2-thioxanthines are mechanism-based inactivators of myeloperoxidase that block oxidative stress during inflammation. J Biol Chem 2011; 286:37578-89. [PMID: 21880720 PMCID: PMC3199503 DOI: 10.1074/jbc.m111.266981] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [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: 05/31/2011] [Revised: 08/10/2011] [Indexed: 11/06/2022] Open
Abstract
Myeloperoxidase (MPO) is a prime candidate for promoting oxidative stress during inflammation. This abundant enzyme of neutrophils uses hydrogen peroxide to oxidize chloride to highly reactive and toxic chlorine bleach. We have identified 2-thioxanthines as potent mechanism-based inactivators of MPO. Mass spectrometry and x-ray crystal structures revealed that these inhibitors become covalently attached to the heme prosthetic groups of the enzyme. We propose a mechanism whereby 2-thioxanthines are oxidized, and their incipient free radicals react with the heme groups of the enzyme before they can exit the active site. 2-Thioxanthines inhibited MPO in plasma and decreased protein chlorination in a mouse model of peritonitis. They slowed but did not prevent neutrophils from killing bacteria and were poor inhibitors of thyroid peroxidase. Our study shows that MPO is susceptible to the free radicals it generates, and this Achilles' heel of the enzyme can be exploited to block oxidative stress during inflammation.
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Affiliation(s)
| | | | | | | | - Revathy Senthilmohan
- the Free Radical Research Group, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Francoise Auchère
- the Free Radical Research Group, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | | | | | | | | | | | - Louisa V. Forbes
- the Free Radical Research Group, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Nicholas J. Magon
- the Free Radical Research Group, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Louise N. Paton
- the Free Radical Research Group, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
| | - Guy N. L. Jameson
- the Department of Chemistry, University of Otago, Dunedin 9054, New Zealand, and
| | | | - Anthony J. Kettle
- the Free Radical Research Group, Department of Pathology, University of Otago Christchurch, Christchurch 8140, New Zealand
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