1
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Kim JH, Lee HS, Kwon MJ, Song YR, Kim SG, Kim JK. Role of neutrophil extracellular traps in vascular access thrombosis in hemodialysis patients. Thromb Res 2023; 231:121-127. [PMID: 37857225 DOI: 10.1016/j.thromres.2023.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/16/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023]
Abstract
BACKGROUND A patent vascular access (VA) is a lifeline for hemodialysis (HD) patients. However, vascular access is prone to thrombosis, which, if left untreated, can lead to permanent VA loss and increased mortality. Neutrophil extracellular traps (NETs) are known to be involved in intravascular thrombosis. We evaluated the relationship between NETs and VA thrombosis and their impact on VA prognosis. METHODS A total of 189 patients with VA flow problems were enrolled. Among these, 93 patients underwent percutaneous transluminal angioplasty (PTA) for stenosis, and 96 patients underwent PTA with thrombectomy for thrombosis. Plasma nucleosome, myeloperoxidase-DNA complex, and von Willebrand factor (vWF) were measured as markers of circulating NETs and thrombosis risk, respectively. The primary outcome was permanent VA loss and the secondary outcome was recurrent thrombotic occlusion within 6 months. In addition, the presence of NETs in thrombi was evaluated by histopathological analysis. RESULTS Circulating nucleosome levels were closely associated with plasma vWF levels (r = 0.172, p = 0.025), and both were higher in thrombectomy cases than in PTA alone cases (nucleosome; 0.83 ± 0.70 vs. 0.35 ± 0.26, p < 0.001, vWF: 9.0 ± 7.6 vs. 7.3 ± 6.2, p = 0.038). The highest quartile of nucleosomes (Q4) was associated with an 18-fold increased rate of access thrombotic occlusion (p < 0.001). In addition, multivariate analysis showed that the rates of permanent access loss (HR 2.77, 95 % CI 1.35-5.77) and recurrent thrombosis (HR 2.35, 95 % CI 1.22-4.54) were much higher in patients with the Q4 nucleosome group than in those with Q1-3. In addition, higher neutrophil infiltration and NET expression in thrombi were also associated with poor VA prognosis. CONCLUSIONS Higher levels of circulating NETs and the amount of NET expression in thrombi may be associated with VA thrombosis and poor VA outcomes.
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Affiliation(s)
- Ji Hwan Kim
- Department of Internal Medicine & Kidney Research Institute, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Hyung Seok Lee
- Department of Internal Medicine & Kidney Research Institute, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Mi Jung Kwon
- Department of Pathology, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Young Rim Song
- Department of Internal Medicine & Kidney Research Institute, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Sung Gyun Kim
- Department of Internal Medicine & Kidney Research Institute, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Jwa-Kyung Kim
- Department of Internal Medicine & Kidney Research Institute, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
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2
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Pakkulnan R, Thonglao N, Chareonsudjai S. DNase I and chitosan enhance efficacy of ceftazidime to eradicate Burkholderia pseudomallei biofilm cells. Sci Rep 2023; 13:1059. [PMID: 36658182 PMCID: PMC9852466 DOI: 10.1038/s41598-023-27790-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 01/09/2023] [Indexed: 01/20/2023] Open
Abstract
Biofilm-associated Burkholderia pseudomallei infection contributes to antibiotic resistance and relapse of melioidosis. Burkholderia pseudomallei biofilm matrix contains extracellular DNA (eDNA) that is crucial for biofilm establishment. However, the contribution of eDNA to antibiotic resistance by B. pseudomallei remains unclear. In this study, we first demonstrated in vitro that DNase I with the administration of ceftazidime (CAZ) at 24 h considerably inhibited the 2-day biofilm formation and reduced the number of viable biofilm cells of clinical B. pseudomallei isolates compared to biofilm treated with CAZ alone. A 3-4 log reduction in numbers of viable cells embedded in the 2-day biofilm was observed when CAZ was combined with DNase I. Confocal laser-scanning microscope visualization emphasized the competence of DNase I followed by CAZ supplementation to significantly limit B. pseudomallei biofilm development and to eradicate viable embedded B. pseudomallei biofilm cells. Furthermore, DNase I supplemented with chitosan (CS) linked with CAZ (CS/CAZ) significantly eradicated shedding planktonic and biofilm cells. These findings indicated that DNase I effectively degraded eDNA leading to biofilm inhibition and dispersion, subsequently allowing CAZ and CS/CAZ to eradicate both shedding planktonic and embedded biofilm cells. These findings provide efficient strategies to interrupt biofilm formation and improve antibiotic susceptibility of biofilm-associated infections.
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Affiliation(s)
- Rattiyaphorn Pakkulnan
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Nuttaya Thonglao
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Sorujsiri Chareonsudjai
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand. .,Research and Diagnostic Center for Emerging Infectious Diseases (RCEID), Khon Kaen University, Khon Kaen, Thailand.
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3
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Kratochvil MJ, Kaber G, Demirdjian S, Cai PC, Burgener EB, Nagy N, Barlow GL, Popescu M, Nicolls MR, Ozawa MG, Regula DP, Pacheco-Navarro AE, Yang S, de Jesus Perez VA, Karmouty-Quintana H, Peters AM, Zhao B, Buja ML, Johnson PY, Vernon RB, Wight TN, Milla CE, Rogers AJ, Spakowitz AJ, Heilshorn SC, Bollyky PL. Biochemical, biophysical, and immunological characterization of respiratory secretions in severe SARS-CoV-2 infections. JCI Insight 2022; 7:152629. [PMID: 35730564 PMCID: PMC9309048 DOI: 10.1172/jci.insight.152629] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 05/10/2022] [Indexed: 01/27/2023] Open
Abstract
Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e., resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We found the percentages of solids and protein content were greatly elevated in COVID-19 compared with heathy control samples and closely resembled levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) were major components of respiratory secretions in COVID-19 and were likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibited heterogeneous rheological behaviors, with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observed increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor-stimulated gene-6 staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicated that increases in HA and DNA in COVID-19 respiratory secretion samples correlated with enhanced inflammatory burden and suggested that DNA and HA may be viable therapeutic targets in COVID-19 infection.
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Affiliation(s)
- Michael J. Kratochvil
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.,Department of Materials Science and Engineering and
| | - Gernot Kaber
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Sally Demirdjian
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Pamela C. Cai
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | | | - Nadine Nagy
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Graham L. Barlow
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Medeea Popescu
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Mark R. Nicolls
- Department of Pulmonology, Allergy and Critical Care Medicine
| | | | | | | | - Samuel Yang
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, California, USA
| | | | - Harry Karmouty-Quintana
- Department of Biochemistry and Molecular Biology;,Divisions of Critical Care Medicine and Pulmonary and Sleep Medicine, Department of Internal Medicine
| | | | - Bihong Zhao
- Department of Pathology and Laboratory Medicine; and,Department of Internal Medicine, University of Texas Health Science Center — McGovern Medical School, Houston, Texas, USA
| | - Maximilian L. Buja
- Department of Pathology and Laboratory Medicine; and,Department of Internal Medicine, University of Texas Health Science Center — McGovern Medical School, Houston, Texas, USA
| | - Pamela Y. Johnson
- Matrix Biology Program, Benaroya Research Institute, Seattle, Washington, USA
| | - Robert B. Vernon
- Matrix Biology Program, Benaroya Research Institute, Seattle, Washington, USA
| | - Thomas N. Wight
- Matrix Biology Program, Benaroya Research Institute, Seattle, Washington, USA
| | | | - Carlos E. Milla
- Center for Excellence in Pulmonary Biology, Department of Pediatrics
| | | | - Andrew J. Spakowitz
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | | | - Paul L. Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
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4
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Kratochvil MJ, Kaber G, Demirdjian S, Cai PC, Burgener EB, Nagy N, Barlow GL, Popescu M, Nicolls MR, Ozawa MG, Regula DP, Pacheco-navarro AE, Yang S, de Jesus Perez VA, Karmouty-quintana H, Peters AM, Zhao B, Buja ML, Johnson PY, Vernon RB, Wight TN, Milla CE, Rogers AJ, Spakowitz AJ, Heilshorn SC, Bollyky PL, Stanford COVID-19 Biobank Study Group. Biochemical, Biophysical, and Immunological Characterization of Respiratory Secretions in Severe SARS-CoV-2 (COVID-19) Infections.. [PMID: 35411348 PMCID: PMC8996635 DOI: 10.1101/2022.03.28.22272848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19 disease, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e. resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We find the percent solids and protein content are greatly elevated in COVID-19 compared to heathy control samples and closely resemble levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) are major components of respiratory secretions in COVID-19 and are likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibit heterogeneous rheological behaviors with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observe increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor–stimulated gene-6 (TSG6) staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicate that increases in HA and DNA in COVID-19 respiratory secretion samples correlate with enhanced inflammatory burden and suggest that DNA and HA may be viable therapeutic targets in COVID-19 infection.
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5
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Shi C, Yang L, Braun A, Anders HJ. Extracellular DNA-A Danger Signal Triggering Immunothrombosis. Front Immunol 2020; 11:568513. [PMID: 33117353 PMCID: PMC7575749 DOI: 10.3389/fimmu.2020.568513] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/09/2020] [Indexed: 12/14/2022] Open
Abstract
Clotting and inflammation are effective danger response patterns positively selected by evolution to limit fatal bleeding and pathogen invasion upon traumatic injuries. As a trade-off, thrombotic, and thromboembolic events complicate severe forms of infectious and non-infectious states of acute and chronic inflammation, i.e., immunothrombosis. Factors linked to thrombosis and inflammation include mediators released by platelet granules, complement, and lipid mediators and certain integrins. Extracellular deoxyribonucleic acid (DNA) was a previously unrecognized cellular component in the blood, which elicits profound proinflammatory and prothrombotic effects. Pathogens trigger the release of extracellular DNA together with other pathogen-associated molecular patterns. Dying cells in the inflamed or infected tissue release extracellular DNA together with other danger associated molecular pattern (DAMPs). Neutrophils release DNA by forming neutrophil extracellular traps (NETs) during infection, trauma or other forms of vascular injury. Fluorescence tissue imaging localized extracellular DNA to sites of injury and to intravascular thrombi. Functional studies using deoxyribonuclease (DNase)-deficient mouse strains or recombinant DNase show that extracellular DNA contributes to the process of immunothrombosis. Here, we review rodent models of immunothrombosis and the evolving evidence for extracellular DNA as a driver of immunothrombosis and discuss challenges and prospects for extracellular DNA as a potential therapeutic target.
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Affiliation(s)
- Chongxu Shi
- Renal Division, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ludwig-Maximilians University Munich, Munich, Germany
| | - Luying Yang
- Renal Division, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ludwig-Maximilians University Munich, Munich, Germany
| | - Attila Braun
- German Center for Lung Research, Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians University Munich, Munich, Germany
| | - Hans-Joachim Anders
- Renal Division, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ludwig-Maximilians University Munich, Munich, Germany
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6
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Kaber G, Kratochvil MJ, Burgener EB, Peltan EL, Barlow G, Yang S, Nicolls MR, de Jesus Perez V, Rosser JI, Wardle AJ, Kalinowski A, Ozawa MG, Regula DP, Nagy N, Heilshorn SC, Milla CE, Rogers AJ, Bollyky PL. Hyaluronan is abundant in COVID-19 respiratory secretions. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020. [PMID: 32935110 DOI: 10.1101/2020.09.11.20191692] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
COVID-19 respiratory infections are associated with copious, adherent respiratory secretions that prolong chronic ventilation and contribute to the morbidity and mortality caused by the disease. We hypothesized that hyaluronan, an extracellular matrix glycosaminoglycan produced at sites of active inflammation that promotes edema in other settings, might be a component of these secretions. To interrogate this, we examined the respiratory secretions collected from eight intubated patients with COVID-19, six control patients with cystic fibrosis (CF), a different respiratory disease also associated with thick adherent secretions, and eight healthy controls. In this sample set we found that hyaluronan content is increased approximately 20-fold in both CF and COVID-19 patients compared to healthy controls. The hyaluronan in COVID-19 samples was comprised of low-molecular weight fragments, the hyaluronan form most strongly linked with pro-inflammatory functions. Hyaluronan is similarly abundant in histologic sections from cadaveric lung tissue from COVID-19 patients. These findings implicate hyaluronan in the thick respiratory secretions characteristic of COVID-19 infection. Therapeutic strategies targeting hyaluronan should be investigated further for potential use in patients with COVID-19.
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7
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Kim SW, Lee JK. Role of HMGB1 in the Interplay between NETosis and Thrombosis in Ischemic Stroke: A Review. Cells 2020; 9:cells9081794. [PMID: 32731558 PMCID: PMC7464684 DOI: 10.3390/cells9081794] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 12/17/2022] Open
Abstract
Neutrophil extracellular traps (NETs) comprise decondensed chromatin, histones and neutrophil granular proteins and are involved in the response to infectious as well as non-infectious diseases. The prothrombotic activity of NETs has been reported in various thrombus-related diseases; this activity can be attributed to the fact that the NETs serve as a scaffold for cells and numerous coagulation factors and stimulate fibrin deposition. A crosstalk between NETs and thrombosis has been indicated to play a role in numerous thrombosis-related conditions including stroke. In cerebral ischemia, neutrophils are the first group of cells to infiltrate the damaged brain tissue, where they produce NETs in the brain parenchyma and within blood vessels, thereby aggravating inflammation. Increasing evidences suggest the connection between NETosis and thrombosis as a possible cause of “tPA resistance”, a problem encountered during the treatment of stroke patients. Several damage-associated molecular pattern molecules have been proven to induce NETosis and thrombosis, with high mobility group box 1 (HMGB1) playing a critical role. This review discusses NETosis and thrombosis and their crosstalk in various thrombosis-related diseases, focusing on the role of HMGB1 as a mediator in stroke. We also addresses the function of peptidylarginine deiminase 4 with respect to the interplay with HMGB1 in NET-induced thrombosis.
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Affiliation(s)
- Seung-Woo Kim
- Department of Biomedical Sciences, Inha University School of Medicine, Inchon 22212, Korea;
- Medical Research Center, Inha University School of Medicine, Inchon 22212, Korea
| | - Ja-Kyeong Lee
- Medical Research Center, Inha University School of Medicine, Inchon 22212, Korea
- Department of Anatomy, Inha University School of Medicine, Inchon 22212, Korea
- Correspondence: ; Tel.: +82-32-860-9893; Fax: +82-32-884-2105
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8
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Thålin C, Hisada Y, Lundström S, Mackman N, Wallén H. Neutrophil Extracellular Traps: Villains and Targets in Arterial, Venous, and Cancer-Associated Thrombosis. Arterioscler Thromb Vasc Biol 2019; 39:1724-1738. [PMID: 31315434 DOI: 10.1161/atvbaha.119.312463] [Citation(s) in RCA: 242] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent studies have demonstrated a role of neutrophils in both venous and arterial thrombosis. A key prothrombotic feature of neutrophils is their ability to release web-like structures composed of DNA filaments coated with histones and granule proteins referred to as neutrophil extracellular traps (NETs). NETs were discovered over a decade ago as part of our first line of host defense against invading microorganisms. Although NETs have a protective role against pathogens, recent data suggest that an uncontrolled and excessive NET formation within the vasculature may contribute to pathological thrombotic disorders. In vitro studies suggest that NETs promote vessel occlusion by providing a scaffold for platelets, red blood cells, extracellular vesicles, and procoagulant molecules, such as von Willebrand factor and tissue factor. In addition, NET components enhance coagulation by both activating the intrinsic pathway and degrading an inhibitor of the extrinsic pathway (tissue factor pathway inhibitor). NET formation has, therefore, been proposed to contribute to thrombus formation and propagation in arterial, venous, and cancer-associated thrombosis. This review will describe animal and human studies suggesting a role of NETs in the pathogenesis of various thrombotic disorders. Targeting NETs may be a novel approach to reduce thrombosis without affecting hemostasis.
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Affiliation(s)
- Charlotte Thålin
- From the Division of Internal Medicine, Department of Clinical Sciences, Danderyd Hospital (C.T.), Karolinska Institutet, Stockholm, Sweden
| | - Yohei Hisada
- Division of Hematology and Oncology, Department of Medicine, University of North Carolina at Chapel Hill (Y.H., N.M.)
| | - Staffan Lundström
- Department of Oncology-Pathology (S.L.), Karolinska Institutet, Stockholm, Sweden.,Palliative Care Services and R&D-Unit, Stockholms Sjukhem Foundation, Sweden (S.L.)
| | - Nigel Mackman
- Division of Hematology and Oncology, Department of Medicine, University of North Carolina at Chapel Hill (Y.H., N.M.)
| | - Håkan Wallén
- Division of Cardiovascular Medicine (H.W.), Karolinska Institutet, Stockholm, Sweden
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9
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Ye J, Shao C, Zhang X, Guo X, Gao P, Cen Y, Ma S, Liu Y. Effects of DNase I coating of titanium on bacteria adhesion and biofilm formation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 78:738-747. [DOI: 10.1016/j.msec.2017.04.078] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 01/04/2017] [Accepted: 04/14/2017] [Indexed: 10/19/2022]
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10
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Exercise is a potent stimulus for enhancing circulating DNase activity. Clin Biochem 2014; 47:471-4. [DOI: 10.1016/j.clinbiochem.2013.12.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/02/2013] [Accepted: 12/15/2013] [Indexed: 11/22/2022]
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11
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Das T, Sehar S, Manefield M. The roles of extracellular DNA in the structural integrity of extracellular polymeric substance and bacterial biofilm development. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:778-86. [PMID: 24249286 DOI: 10.1111/1758-2229.12085] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/25/2013] [Accepted: 05/04/2013] [Indexed: 05/22/2023]
Abstract
Bacteria adhere to natural and engineered surfaces and develop into mature biofilms encased in self-produced extracellular polymeric substances (EPSs). EPS consists of polysaccharides, proteins, metabolites and extracellular DNA (eDNA). Extracellular DNA release by bacteria is mediated by both quorum-sensing (QS)-dependent and -independent mechanisms. Quorum-sensing-independent mechanisms are responsible for basal levels of eDNA release, whereas QS-dependent mechanisms control the production of prophages, phenazines and proteins involved in cell lysis and subsequent release of elevated amounts of eDNA. Extracellular DNA binds with other biopolymers such as polysaccharides, proteins or metabolites like phenazines, thereby providing structural integrity to EPS. Extracellular DNA promotes attractive acid-base interactions between bacterial cells and between bacteria and surfaces. It therefore plays an essential structural role in stabilising biofilms and protecting bacterial cells from physical and chemical challenges. Accordingly, with current knowledge, it becomes clear that targeting and destroying eDNA in bacterial EPS is a promising strategy for treatment of bacterial-associated infections in a medical context and biofilm control on surfaces to prevent biocorrison in an engineering context. In contrast, the addition of DNA can be applied to engineering of biofilms for beneficial purposes such as remediation of environmental pollutants and electricity or fuel production in bioelectrochemical systems or bioreactors.
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Affiliation(s)
- Theerthankar Das
- Centre for Marine BioInnovation (CMB), School of Biotechnology and Biomolecular Sciences (BABS), University of New South Wales (UNSW), Sydney, NSW, 2052, Australia
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12
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Das T, Manefield M. Phenazine production enhances extracellular DNA release via hydrogen peroxide generation in Pseudomonas aeruginosa. Commun Integr Biol 2013; 6:e23570. [PMID: 23710274 PMCID: PMC3656008 DOI: 10.4161/cib.23570] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 01/09/2013] [Accepted: 01/10/2013] [Indexed: 11/19/2022] Open
Abstract
In Pseudomonas aeruginosa eDNA is a crucial component essential for biofilm formation and stability. In this study we report that release of eDNA is influenced by the production of phenazine in P. aeruginosa. A ∆phzA-G mutant of P. aeruginosa PA14 deficient in phenazine production generated significantly less eDNA in comparison with the phenazine producing strains. The relationship between eDNA release and phenazine production is bridged via hydrogen peroxide (H2O2) generation and subsequent H2O2 mediated cell lysis and ultimately release of chromosomal DNA into the extracellular environment as eDNA.
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Affiliation(s)
- Theerthankar Das
- Centre for Marine BioInnovation (CMB); School of Biotechnology and Biomolecular Sciences (BABS); University of New South Wales (UNSW); Sydney, NSW Australia
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13
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Cho H, Guo Y, Sosnovik DE, Josephson L. Imaging DNA with fluorochrome bearing metals. Inorg Chem 2013; 52:12216-22. [PMID: 23646914 DOI: 10.1021/ic400404g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecules that fluoresce upon binding DNA are widely used in assaying and visualizing DNA in cells and tissues. However, using light to visualize DNA in animals is limited by the attenuation of light transmission by biological tissues. Moreover, it is now clear that DNA is an important mediator of dead cell clearance, coagulation reactions, and an immunogen in autoimmune lupus. Attaching metals (e.g., superparamagnetic nanoparticles, gadolinium ions, radioactive metal ions) to DNA-binding fluorochromes provides a way of imaging DNA in whole animals, and potentially humans, without light. Imaging metal-bearing, DNA-binding fluorochromes and their target DNA by magnetic resonance imaging may shed light on the many key roles of DNA in health and disease beyond the storage of genetic information.
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Affiliation(s)
- Hoonsung Cho
- Center for Translational Nuclear Medicine and Molecular Imaging, ‡Martinos Center for Biomedical Imaging, Department of Radiology, and §Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School , Boston, Massachusetts 02114, United States
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14
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Das T, Kutty SK, Kumar N, Manefield M. Pyocyanin facilitates extracellular DNA binding to Pseudomonas aeruginosa influencing cell surface properties and aggregation. PLoS One 2013; 8:e58299. [PMID: 23505483 PMCID: PMC3594310 DOI: 10.1371/journal.pone.0058299] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 02/01/2013] [Indexed: 11/26/2022] Open
Abstract
Pyocyanin is an electrochemically active metabolite produced by the human pathogen Pseudomonas aeruginosa. It is a recognized virulence factor and is involved in a variety of significant biological activities including gene expression, maintaining fitness of bacterial cells and biofilm formation. It is also recognized as an electron shuttle for bacterial respiration and as an antibacterial and antifungal agent. eDNA has also been demonstrated to be a major component in establishing P. aeruginosa biofilms. In this study we discovered that production of pyocyanin influences the binding of eDNA to P. aeruginosa PA14 cells, mediated through intercalation of pyocyanin with eDNA. P. aeruginosa cell surface properties including cell size (hydrodynamic diameter), hydrophobicity and attractive surface energies were influenced by eDNA in the presence of pyocyanin, affecting physico-chemical interactions and promoting aggregation. A ΔphzA-G PA14 mutant, deficient in pyocynain production, could not bind with eDNA resulting in a reduction in hydrodynamic diameter, a decrease in hydrophobicity, repulsive physico-chemical interactions and reduction in aggregation in comparison to the wildtype strain. Removal of eDNA by DNase I treatment on the PA14 wildtype strain resulted in significant reduction in aggregation, cell surface hydrophobicity and size and an increase in repulsive physico-chemical interactions, similar to the level of the ΔphzA-G mutant. The cell surface properties of the ΔphzA-G mutant were not affected by DNase I treatment. Based on these findings we propose that pyocyanin intercalation with eDNA promotes cell-to-cell interactions in P. aeruginosa cells by influencing their cell surface properties and physico-chemical interactions.
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Affiliation(s)
- Theerthankar Das
- Centre for Marine BioInnovation (CMB), School of Biotechnology and Biomolecular Sciences (BABS), University of New South Wales (UNSW), Sydney, Australia.
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15
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Oklu R, Albadawi H, Watkins MT, Monestier M, Sillesen M, Wicky S. Detection of extracellular genomic DNA scaffold in human thrombus: implications for the use of deoxyribonuclease enzymes in thrombolysis. J Vasc Interv Radiol 2012; 23:712-8. [PMID: 22525027 DOI: 10.1016/j.jvir.2012.01.072] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 01/20/2012] [Accepted: 01/20/2012] [Indexed: 01/04/2023] Open
Abstract
PURPOSE Mechanisms underlying transition of a thrombus susceptible to tissue plasminogen activator (TPA) fibrinolysis to one that is resistant is unclear. Demonstration of a new possible thrombus scaffold may open new avenues of research in thrombolysis and may provide mechanistic insight into thrombus remodeling. MATERIALS AND METHODS Ten human thrombus samples were collected during cases of thrombectomy and open surgical repair of abdominal aortic aneurysms (five samples < 3 d old and five samples > 1 y old). Additionally, an acute murine hindlimb ischemia model was created to evaluate thrombus samples in mice. Human sections were immunostained for the H2A/H2B/DNA complex, myeloperoxidase, fibrinogen, and von Willebrand factor. Mouse sections were immunostained with the H2A antibody. All samples were further evaluated after hematoxylin and eosin and Masson trichrome staining. RESULTS An extensive network of extracellular histone/DNA complex was demonstrated in the matrix of human ex vivo thrombus. This network is present throughout the highly cellular acute thrombus. However, in chronic thrombi, detection of the histone/DNA network was predominantly in regions of low collagen content and high cell density, which were mostly near the lumen. These regions of high cell density contained neutrophils and monocytes. Similarly, sections from the acute murine hindlimb ischemia model also exhibited extensive immunoreactivity to the histone antibody in the extracellular space within murine thrombi. CONCLUSIONS Extensive detection of genomic DNA associated with histones in the extracellular matrix of human and mouse thrombi suggest the presence of a new thrombus-associated scaffold.
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Affiliation(s)
- Rahmi Oklu
- Division of Vascular Imaging and Intervention, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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Tiddens HA. Editorial for effect of dornase alfa on inflammation and lung function: Potential role in the early treatment of cystic fibrosis. J Cyst Fibros 2012; 11:77. [DOI: 10.1016/j.jcf.2012.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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