1
|
Cont D, Harm S, Schildböck C, Kolm C, Kirschner AKT, Farnleitner AH, Pilecky M, Zottl J, Hartmann J, Weber V. The neutralizing effect of heparin on blood-derived antimicrobial compounds: impact on antibacterial activity and inflammatory response. Front Immunol 2024; 15:1373255. [PMID: 38585266 PMCID: PMC10995223 DOI: 10.3389/fimmu.2024.1373255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/13/2024] [Indexed: 04/09/2024] Open
Abstract
Acting through a combination of direct and indirect pathogen clearance mechanisms, blood-derived antimicrobial compounds (AMCs) play a pivotal role in innate immunity, safeguarding the host against invading microorganisms. Besides their antimicrobial activity, some AMCs can neutralize endotoxins, preventing their interaction with immune cells and avoiding an excessive inflammatory response. In this study, we aimed to investigate the influence of unfractionated heparin, a polyanionic drug clinically used as anticoagulant, on the endotoxin-neutralizing and antibacterial activity of blood-derived AMCs. Serum samples from healthy donors were pre-incubated with increasing concentrations of heparin for different time periods and tested against pathogenic bacteria (Acinetobacter baumannii, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus) and endotoxins from E. coli, K. pneumoniae, and P. aeruginosa. Heparin dose-dependently decreased the activity of blood-derived AMCs. Consequently, pre-incubation with heparin led to increased activity of LPS and higher values of the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Accordingly, higher concentrations of A. baumannii, E. coli, K. pneumoniae, and P. aeruginosa were observed as well. These findings underscore the neutralizing effect of unfractionated heparin on blood-derived AMCs in vitro and may lead to alternative affinity techniques for isolating and characterizing novel AMCs with the potential for clinical translation.
Collapse
Affiliation(s)
- Denisa Cont
- Department for Biomedical Research, University for Continuing Education Krems, Krems an der Donau, Austria
- Department of Physiology, Pharmacology and Microbiology, Division Water Quality and Health, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
| | - Stephan Harm
- Department for Biomedical Research, University for Continuing Education Krems, Krems an der Donau, Austria
| | - Claudia Schildböck
- Department for Biomedical Research, University for Continuing Education Krems, Krems an der Donau, Austria
| | - Claudia Kolm
- Department of Physiology, Pharmacology and Microbiology, Division Water Quality and Health, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Microbiology and Molecular Diagnostics, Vienna University of Technology, Vienna, Austria
| | - Alexander K. T. Kirschner
- Department of Physiology, Pharmacology and Microbiology, Division Water Quality and Health, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
- Institute for Hygiene and Applied Immunology, Water Microbiology, Medical University of Vienna, Vienna, Austria
| | - Andreas H. Farnleitner
- Department of Physiology, Pharmacology and Microbiology, Division Water Quality and Health, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Microbiology and Molecular Diagnostics, Vienna University of Technology, Vienna, Austria
| | - Matthias Pilecky
- Research Lab Aquatic Ecosystem Research and Health, University for Continuing Education Krems, Krems an der Donau, Austria
- Water Cluster Lunz Biological Station, Lunz, Austria
| | - Jennifer Zottl
- Department for Biomedical Research, University for Continuing Education Krems, Krems an der Donau, Austria
| | - Jens Hartmann
- Department for Biomedical Research, University for Continuing Education Krems, Krems an der Donau, Austria
| | - Viktoria Weber
- Department for Biomedical Research, University for Continuing Education Krems, Krems an der Donau, Austria
| |
Collapse
|
2
|
Harm S, Schildböck C, Cont D, Weber V. Heparin enables the reliable detection of endotoxin in human serum samples using the Limulus amebocyte lysate assay. Sci Rep 2024; 14:2410. [PMID: 38287051 PMCID: PMC10825173 DOI: 10.1038/s41598-024-52735-8] [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: 07/28/2023] [Accepted: 01/23/2024] [Indexed: 01/31/2024] Open
Abstract
The determination of lipopolysaccharide (endotoxin) in serum or plasma samples using Limulus amebocyte lysate (LAL)-based assays is currently not sufficiently reliable in clinical diagnostics due to numerous interfering factors that strongly reduce the recovery of LPS in clinical samples. The specific plasma components responsible for the endotoxin neutralizing capacity of human blood remain to be identified. There are indications that certain endotoxin-neutralizing proteins or peptides, which are part of the host defense peptides/proteins of the innate immune system may be responsible for this effect. Based on our finding that several antimicrobial peptides can be neutralized by the polyanion heparin, we developed a heparin-containing diluent for serum and plasma samples, which enables reliable quantification of LPS measurement in clinical samples using the LAL assay. In a preclinical study involving 40 donors, this improved protocol yielded an over eightfold increase in LPS recovery in serum samples, as compared to the standard protocol. This modified protocol of sample pretreatment could make LPS measurement a valuable tool in medical diagnostics.
Collapse
Affiliation(s)
- Stephan Harm
- Department for Biomedical Research, University for Continuing Education Krems, Krems, Austria.
| | - Claudia Schildböck
- Department for Biomedical Research, University for Continuing Education Krems, Krems, Austria
| | - Denisa Cont
- Department for Biomedical Research, University for Continuing Education Krems, Krems, Austria
- Department of Pharmacology, Physiology, and Microbiology, Karl Landsteiner University, Krems, Austria
| | - Viktoria Weber
- Department for Biomedical Research, University for Continuing Education Krems, Krems, Austria
| |
Collapse
|
3
|
Dowler KK, Vientós-Plotts A, Giuliano EA, McAdams ZL, Dorfmeyer RA, Reinero CR, Ericsson AC. Ophthalmic viscoelastics commonly used in cataract surgery: A microbiota investigation. Vet Ophthalmol 2023. [PMID: 36772992 DOI: 10.1111/vop.13068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/12/2023]
Abstract
PURPOSE To survey commonly used, sterile ophthalmic viscoelastic materials used during routine cataract surgery for the presence of bacterial DNA and/or viable bacteria and endotoxin quantification. METHODS Samples from three different ophthalmic viscoelastic manufacturers and three different production lots per manufacturer were collected for 16 S ribosomal ribonucleic acid (rRNA) sequencing and conventional aerobic and capnophilic bacterial culture. Other samples of viscoelastic material from the same three manufacturers were collected for endotoxin quantification using a commercially available Limulus amebocyte lysate (LAL) assay. Statistical analysis was performed using Sigma Plot 14.0, and R v4.0.2.0. Differences (p ≤ .05) between sample collection sites in total DNA concentration, microbial richness, mean intra-group distances, and endotoxin quantification alongside reagent controls were evaluated. RESULTS Culture yielded two isolates, identified as Staphylococcus epidermidis and Bacillus megaterium. 16 S rRNA sequencing revealed no differences between brands in richness or overall composition. The most common bacterial DNA detected across all brands was Staphylococcus sp., Cutibacterium sp., Flavobacterium sp., and Lactobacillus sp. A significant difference was found between the median endotoxin concentration between Anvision and Hyvisc® viscoelastic (Anvision: 0.171 EU/mL, Hyvisc®: 0.03 EU/mL; p < .001). CONCLUSIONS No brand-specific differences in bacterial DNA were detected in the viscoelastic materials. Staphylococcus, Cutibacterium, Flavobacterium, and Lactobacillus were the dominant contributors to the bacterial DNA detected. Although Anvision viscoelastic samples contained significantly more endotoxin than Hyvisc® viscoelastic samples, endotoxin concentrations were below the FDA limit of 0.2 EU/mL for both manufacturers. These data further the understanding of inflammatory outcomes following cataract surgery.
Collapse
Affiliation(s)
- Kourtney K Dowler
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Aida Vientós-Plotts
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Elizabeth A Giuliano
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Zachary L McAdams
- Molecular Pathogenesis and Therapeutics Program, University of Missouri, Columbia, Missouri, USA
| | - Rebecca A Dorfmeyer
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Carol R Reinero
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Aaron C Ericsson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| |
Collapse
|
4
|
Adda-Rezig H, Carron C, Pais de Barros JP, Choubley H, Charron É, Rérole AL, Laheurte C, Louvat P, Gaiffe É, Simula-Faivre D, Deckert V, Lagrost L, Saas P, Ducloux D, Bamoulid J. New Insights on End-Stage Renal Disease and Healthy Individual Gut Bacterial Translocation: Different Carbon Composition of Lipopolysaccharides and Different Impact on Monocyte Inflammatory Response. Front Immunol 2021; 12:658404. [PMID: 34163471 PMCID: PMC8215383 DOI: 10.3389/fimmu.2021.658404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/18/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic kidney disease induces disruption of the intestinal epithelial barrier, leading to gut bacterial translocation. Here, we appreciated bacterial translocation by analyzing circulating lipopolysaccharides (LPS) using two methods, one measuring only active free LPS, and the other quantifying total LPS as well as LPS lipid A carbon chain length. This was done in end-stage renal disease (ESRD) patients and healthy volunteers (HV). We observed both higher LPS concentration in healthy volunteers and significant differences in composition of translocated LPS based on lipid A carbon chain length. Lower LPS activity to mass ratio and higher concentration of high-density lipoproteins were found in HV, suggesting a better plasma capacity to neutralize LPS activity. Higher serum concentrations of soluble CD14 and pro-inflammatory cytokines in ESRD patients confirmed this hypothesis. To further explore whether chronic inflammation in ESRD patients could be more related to LPS composition rather than its quantity, we tested the effect of HV and patient sera on cytokine secretion in monocyte cultures. Sera with predominance of 14-carbon chain lipid A-LPS induced higher secretion of pro-inflammatory cytokines than those with predominance of 18-carbon chain lipid A-LPS. TLR4 or LPS antagonists decreased LPS-induced cytokine production by monocytes, demonstrating an LPS-specific effect. Thereby, septic inflammation observed in ESRD patients may be not related to higher bacterial translocation, but to reduced LPS neutralization capacity and differences in translocated LPS subtypes.
Collapse
Affiliation(s)
- Hanane Adda-Rezig
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France
| | - Clémence Carron
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France
| | | | - Hélène Choubley
- INSERM, Univ. Bourgogne Franche-Comté, LNC UMR1231, LabEx LipSTIC, Dijon, France
| | - Émilie Charron
- INSERM, Univ. Bourgogne Franche-Comté, LNC UMR1231, LabEx LipSTIC, Dijon, France
| | - Anne-Laure Rérole
- INSERM, Univ. Bourgogne Franche-Comté, LNC UMR1231, LabEx LipSTIC, Dijon, France
| | - Caroline Laheurte
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,EFS Bourgogne Franche-Comté, Plateforme de BioMonitoring, Besançon, France
| | - Pascale Louvat
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,EFS Bourgogne Franche-Comté, Plateforme de BioMonitoring, Besançon, France
| | - Émilie Gaiffe
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,INSERM CIC1431, University Hospital of Besançon, Clinical Investigation Center in Biotherapy, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France
| | - Dominique Simula-Faivre
- University Hospital of Besançon, Department of Nephrology, Dialysis, and Renal Transplantation, Besançon, France
| | - Valérie Deckert
- INSERM, Univ. Bourgogne Franche-Comté, LNC UMR1231, LabEx LipSTIC, Dijon, France
| | - Laurent Lagrost
- INSERM, Univ. Bourgogne Franche-Comté, LNC UMR1231, LabEx LipSTIC, Dijon, France
| | - Philippe Saas
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,EFS Bourgogne Franche-Comté, Plateforme de BioMonitoring, Besançon, France.,INSERM CIC1431, University Hospital of Besançon, Clinical Investigation Center in Biotherapy, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France
| | - Didier Ducloux
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,INSERM CIC1431, University Hospital of Besançon, Clinical Investigation Center in Biotherapy, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,University Hospital of Besançon, Department of Nephrology, Dialysis, and Renal Transplantation, Besançon, France
| | - Jamal Bamoulid
- Univ. Bourgogne Franche-Comté, INSERM, EFS BFC, UMR1098, RIGHT Interactions Hôte Greffon-Tumeur/Ingénierie Cellulaire et Génique, Fédération Hospitalo-Universitaire INCREASE, LabEx LipSTIC, Besançon, France.,University Hospital of Besançon, Department of Nephrology, Dialysis, and Renal Transplantation, Besançon, France
| |
Collapse
|
5
|
An in vitro study on factors affecting endotoxin neutralization in human plasma using the Limulus amebocyte lysate test. Sci Rep 2021; 11:4192. [PMID: 33603020 PMCID: PMC7893160 DOI: 10.1038/s41598-021-83487-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 01/21/2021] [Indexed: 01/14/2023] Open
Abstract
Endotoxin neutralization, caused by plasma components, makes it difficult to detect endotoxins in human blood. In this study, we investigated which factors influence the recovery of endotoxins using limulus ameobocyte lysate (LAL)-based assays. The individual factors that were examined in more detail were lipoprotein content, type of blood anticoagulation, kinetics and serum levels of divalent cations. Furthermore, it was investigated whether there is a direct correlation between LAL activity and monocyte activation. We could show that polyanionic heparin increases endotoxin recovery in blood, while citrate anticoagulation promotes endotoxin neutralization. Furthermore, we could show that the endotoxin activity in human plasma and serum decreases strongly over time. Time-dependent endotoxin neutralization reaches its maximum after 4–6 h incubation. By means of filtration tests we could determine that endotoxins in the plasma bind to lipoproteins but do not influence their activity. Comparative measurements have shown that high LAL activity of endotoxins in plasma simultaneously possesses high monocyte activating properties in whole blood. For the maximum recovery of endotoxins in human blood the physiological calcium and magnesium concentrations are sufficient. In this study, it was shown that the endotoxin neutralizing plasma components have a molecular weight similar to β2-microglobulin (11.7 kDa). For the exact identification of the endotoxin neutralizing plasma components, which caused a modulation of the immunostimulating endotoxin activity, further investigations have to be carried out in the future.
Collapse
|
6
|
Mohammadi H, Manouchehri H, Changizi R, Bootorabi F, Khorramizadeh MR. Concurrent metformin and silibinin therapy in diabetes: assessments in zebrafish ( Danio rerio) animal model. J Diabetes Metab Disord 2020; 19:1233-1244. [PMID: 33553026 DOI: 10.1007/s40200-020-00637-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/14/2020] [Indexed: 01/11/2023]
Abstract
Objective In this study, zebrafish was used as a biological model to induce type 2 diabetes mellitus through glucose. Then, the effect of metformin and silibinin combination was examined on elevated blood glucose, intestinal tissues, liver enzymes, and TNF-α, IFN-γ, INL1β genes as inflammation marker genes. Methods The liver enzymes (AST, ALT, and ALP) derived from fish viscera homogenate supernatants were assayed in an auto-analyzer. The expression of target genes was quantified on RNA extracted from the tails by an in-house RT-PCR method, with fine intestine tissue staining performed by hematoxylin and eosin protocol (H&E). Result In the glucose-free treatments, metformin and silymarin decreased the levels of AST, ALT, and ALP enzymes in the blood. The combination of these two drugs had also a significant role in reducing glucose levels. The body weight increased significantly in the control group which was affected by glucose concentration, with the lowest body weight gain observed in the metformin group. The expression of INL-1β gene was significantly enhanced in the control group and the highest IFN-γ expression was observed in both control groups with glucose (G + CTRL) and without glucose (G-CTRL) (p < 0.05). The lowest level of TNF-α gene expression was observed in the control + glucose group (G + CTRL) (p < 0.05). Diabetic state causes weak absorption whereby the fish body demands to increase absorption level by enhancing the amount of acidic goblet cells thereby acidifying the environment in the gastric tracts. Conclusion Collectively, this study indicated that treatment with metformin and Silibinin could improve metabolic-mediated performances by reducing the expression of inflammatory genes and blood glucose, modulating liver enzymes, and ameliorating the intestinal inflammation in type 2 diabetic zebrafish model.
Collapse
Affiliation(s)
- Hassan Mohammadi
- Department of Aquaculture Science, Babol Branch, Islamic Azad University, Babol, Iran
| | - Hamed Manouchehri
- Department of Aquaculture Science, Babol Branch, Islamic Azad University, Babol, Iran
| | - Reza Changizi
- Department of Aquaculture Science, Babol Branch, Islamic Azad University, Babol, Iran
| | - Fatemeh Bootorabi
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Mohammad Reza Khorramizadeh
- Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, and Zebra fish core Facility (ZFIN ID : ZDB-LAB-190117-2), Endocrinology and Metabolism research Institute, Tehran university of Medical Sciences, Tehran, Iran
| |
Collapse
|
7
|
Posha B, Sandhyarani N. Highly sensitive endotoxin detection using a gold nanoparticle loaded layered molybdenum disulfide-polyacrylic acid nanocomposite. Analyst 2020; 145:3939-3947. [PMID: 32314985 DOI: 10.1039/d0an00567c] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Endotoxins or lipopolysaccharides (LPS) are pathogens released from the outer membrane of gram-negative bacteria which produce toxic effects on humans. The sensitive and selective detection of LPS is in high demand, especially in the field of medical supplies, therapeutics and in the food industry. Herein we report a new nano-probe based on a gold nanoparticle loaded, water-soluble layered molybdenum disulfide-polyacrylic acid (Au/MoS2-PAA) nanocomposite as a label-free voltammetric aptasensor for ultrasensitive LPS detection. MoS2 nanosheets were obtained through one-step sonication assisted exfoliation of bulk MoS2 with polyacrylic acid (PAA). Au nanoparticles were incorporated into the MoS2-PAA nanocomposite and thiol terminated LPS binding aptamers (LBA) were immobilized on this. The specific binding of LPS with LBA is investigated electrochemically by differential pulse voltammetry. The apparent binding constant (Kb) of LPS with LBA has been calculated to be 1.53 × 102 mL g-1. The aptasensor demonstrated LPS detection down to the ag mL-1 level without incorporating any redox mediator and showed wide linearity from 100 ag mL-1 to 100 pg mL-1 with a low limit of detection of 29 ag mL-1. The sensor showed excellent recovery upon spiking LPS in clinical grade insulin, suggesting that LBA/Au/MoS2-PAA/GCE has promising application for the trace analysis of LPS in the field of pharmaceutical products.
Collapse
Affiliation(s)
- Biyas Posha
- Nanoscience Research Laboratory, School of Materials Science and Engineering, National Institute of Technology, Calicut-673601, Kerala, India.
| | | |
Collapse
|
8
|
Wong J, Zhang Y, Swift O, Finkelman M, Patidar A, Ramanarayanan S, Vilar E, Farrington K. Beta-glucans in advanced CKD: role in endotoxaemia and inflammation. BMC Nephrol 2020; 21:118. [PMID: 32252666 PMCID: PMC7137517 DOI: 10.1186/s12882-020-01779-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 03/23/2020] [Indexed: 12/23/2022] Open
Abstract
Background/aims (1–3)-β-D glucans (BG) are cellular components of yeasts and fungi. Elevated blood levels may be an adjunct in diagnosing invasive fungal infection, though can be high in dialysis patients without fungaemia. BG can also induce false positive signals in endotoxin detection assays (Limulus Amoebocyte Lysate [LAL] assay). We explored the relationship between BG levels, renal impairment, endotoxaemia and inflammation. Methods We measured serum BG levels, markers of inflammation and blood endotoxin levels in 20 controls, 20 with stages 1–3 chronic kidney disease (CKD), 20 with stages 4–5 CKD, 15 on peritoneal dialysis (PD) and 60 on haemodialysis (HD). Another 30 patients were studied before and after HD initiation. Results BG levels increased with advancing CKD, being highest in HD patients, 22% of whom had elevated levels (> 80 pg/ml). Levels increased significantly following HD initiation. Levels also correlated positively with CRP, TNFα, IL-6 levels, independently of CKD stage. Blood endotoxin was detectable by LAL assays in 10–53% of the CKD cohort, being most prevalent in the HD group, and correlating positively with BG levels. Adding BG blocking agent to the assay reduced endotoxin detection confining it to only 5% of HD patients. Levels of inflammatory markers were higher in those with detectable endotoxin - whether false- or true positives. Conclusion BG levels increased with decreasing renal function, being highest in dialysis patients. High BG levels were associated with false positive blood endotoxin signals, and with markers of inflammation, independently of CKD stage. The cause for high BG levels is unknown but could reflect increased gut permeability and altered mononuclear phagocytic system function.
Collapse
Affiliation(s)
- Jonathan Wong
- Renal Research, East and North Herts NHS Trust, Coreys Mill Lane, Stevenage, SG1 4AB, UK. .,University of Hertfordshire, Hatfield, UK.
| | | | - Oscar Swift
- Renal Research, East and North Herts NHS Trust, Coreys Mill Lane, Stevenage, SG1 4AB, UK
| | | | | | - Sivaramakrishnan Ramanarayanan
- Renal Research, East and North Herts NHS Trust, Coreys Mill Lane, Stevenage, SG1 4AB, UK.,University of Hertfordshire, Hatfield, UK
| | - Enric Vilar
- Renal Research, East and North Herts NHS Trust, Coreys Mill Lane, Stevenage, SG1 4AB, UK.,University of Hertfordshire, Hatfield, UK
| | - Ken Farrington
- Renal Research, East and North Herts NHS Trust, Coreys Mill Lane, Stevenage, SG1 4AB, UK.,University of Hertfordshire, Hatfield, UK
| |
Collapse
|
9
|
Klemperer KM, Reust MJ, Lee MH, Corstjens PLAM, van Dam GJ, Mazigo HD, Dupnik KM, Downs JA. Plasma Endotoxin Levels Are Not Increased in Schistosoma mansoni-Infected Women without Signs or Symptoms of Hepatosplenic Disease. Am J Trop Med Hyg 2020; 102:1382-1385. [PMID: 32124718 DOI: 10.4269/ajtmh.19-0875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Elevated circulating endotoxin levels in the plasma of patients with advanced hepatosplenic schistosomiasis caused by Schistosoma mansoni have been reported, possibly caused by parasite egg-induced intestinal mucosal breaches facilitating bacterial access to the bloodstream. Neither endotoxin levels in people with S. mansoni but without hepatosplenic disease nor the impact of treatment on endotoxin levels have been described. We used a methodically optimized Limulus amebocyte lysate assay to measure plasma endotoxin in community-dwelling women from an S. mansoni-endemic area without clinical hepatosplenic disease. We found no difference in baseline mean plasma endotoxin levels between those with (n = 22) and without (n = 31) infection (1.001 versus 0.949 EU/mL, P = 0.61). Endotoxin levels did not change in schistosome-infected women after successful treatment (1.001 versus 1.093 EU/mL, P = 0.45) and were not correlated with circulating anodic antigen or stool egg burden. Our findings do not support the hypothesis that translocating eggs in S. mansoni infection introduce bacterial sources of endotoxin to the circulation.
Collapse
Affiliation(s)
- Katherine M Klemperer
- St John's College, Cambridge University, Cambridge, United Kingdom.,Department of Medicine, Weill Cornell Medicine, New York, New York
| | | | - Myung Hee Lee
- Department of Medicine, Weill Cornell Medicine, New York, New York
| | - Paul L A M Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Govert J van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Humphrey D Mazigo
- Department of Parasitology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Kathryn M Dupnik
- Department of Medicine, Weill Cornell Medicine, New York, New York
| | - Jennifer A Downs
- Department of Medicine, Weill Cornell Medicine, New York, New York.,Department of Medicine, Bugando Medical Center, Mwanza, Tanzania
| |
Collapse
|
10
|
Yuan Y, Li L, Zhao M, Zhou J, Chen Z, Bai L. An aptamer based voltammetric biosensor for endotoxins using a functionalized graphene and molybdenum disulfide composite as a new nanocarrier. Analyst 2018; 144:1253-1259. [PMID: 30542691 DOI: 10.1039/c8an02139b] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Lipopolysaccharides (LPS), known as endotoxins, can cause a strong inflammatory response and lead to multiple organ failure in severe cases. This work reports a simple label-free voltammetric aptasensor for highly sensitive determination of LPS using a polyethyleneimine (PEI) functionalized reduced graphene oxide (rGO) and molybdenum disulfide (MoS2) composite (PEI-rGO-MoS2) as a new nanocarrier for electroactive toluidine blue (TB). The PEI-rGO-MoS2 nanocomposite with high electrical conductivity and large specific surface area can greatly increase the loading of TB and facilitate electron transfer from TB to an electrode. Then gold nanoparticles (AuNPs) were utilized to immobilize a thiolated LPS binding aptamer (LBA), which not only exhibited excellent biocompatibility, but also significantly amplified the electrochemical signal of TB. The proposed aptasensor exhibited high sensitivity for LPS and showed a wide linear range from 5.0 × 10-5 ng mL-1 to 2.0 × 102 ng mL-1 with a low limit of detection (LOD) of 3.01 × 10-5 ng mL-1, which overcame the shortcomings of traditional detection methods and achieved fast and accurate detection of LPS. Moreover, it exhibited excellent recovery and specificity upon spiking LPS in serum samples, indicating that this method has promising application in the field of trace analysis of LPS in clinical detection.
Collapse
Affiliation(s)
- Yonghua Yuan
- Engineering Technology Research Center for Pharmacodynamic Evaluation of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, PR China.
| | - Linlin Li
- Engineering Technology Research Center for Pharmacodynamic Evaluation of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, PR China.
| | - Min Zhao
- Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China
| | - Jing Zhou
- Engineering Technology Research Center for Pharmacodynamic Evaluation of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, PR China.
| | - Zhihui Chen
- Engineering Technology Research Center for Pharmacodynamic Evaluation of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, PR China.
| | - Lijuan Bai
- Engineering Technology Research Center for Pharmacodynamic Evaluation of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing 400016, PR China.
| |
Collapse
|
11
|
Shendi AM, Davies N, Davenport A. Systemic Endotoxin in Peritoneal Dialysis Patients. Perit Dial Int 2018; 38:381-384. [PMID: 30185481 DOI: 10.3747/pdi.2018.00036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Previous reports linked systemic endotoxemia in dialysis patients to increased markers of inflammation, cardiovascular disease, and mortality. Many peritoneal dialysis (PD) patients use acidic, hypertonic dialysates, which could potentially increase gut permeability, resulting in systemic endotoxemia. However, the results from studies measuring endotoxin in PD patients are discordant. We therefore measured systemic endotoxin in 55 PD outpatients attending for routine assessment of peritoneal membrane function; mean age 58.7 ± 16.4 years, 32 (58.2%) male, 21 (38.2%) diabetic, median duration of PD treatment 19.5 (13 - 31) months, 32 (58.2%) using 22.7 g/L dextrose dialysates, and 47 (85.5%) icodextrin. The median systemic endotoxin concentration was 0.0485 (0.0043 - 0.103) Eu/mL. We found no association between endotoxin levels and patient demographics, markers of inflammation, serum albumin, N-terminal pro-brain natriuretic peptide, extracellular volume measured by bioimpedance, blood pressure, PD prescriptions or peritoneal membrane transporter status, or medications. The measurement of endotoxin can be lowered by failure to effectively release protein-bound endotoxin prior to analysis and increased by contamination when taking blood samples and processing and storing the samples. Additionally, contamination with β-glucan from fungal cell walls and the use of different assays to analyze endotoxin can also give differing results. These factors may help to explain the disparate results reported in different studies. Our study would suggest that exposure to standard peritoneal dialysates does not substantially increase systemic endotoxin. However, until endotoxin assays can measure free and bound endotoxin separately, the role of endotoxin causing inflammation in PD patients remains to be determined.
Collapse
Affiliation(s)
- Ali M Shendi
- Renal Division, Department of Internal Medicine, Zagazig University, Egypt
| | - Nathan Davies
- Institute for Liver & Digestive Health, Royal Free Hospital, UCL Medical School, London, United Kingdom
| | - Andrew Davenport
- UCL Centre for Nephrology, Royal Free Hospital, University College London, London, United Kingdom
| |
Collapse
|
12
|
Zhang Y, Han L, He Q, Chen W, Sun C, Wang X, Chen X, Wang R, Hsiao CD, Liu K. A rapid assessment for predicting drug-induced hepatotoxicity using zebrafish. J Pharmacol Toxicol Methods 2017; 84:102-110. [DOI: 10.1016/j.vascn.2016.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 11/09/2016] [Accepted: 12/06/2016] [Indexed: 12/12/2022]
|
13
|
Wong J, Davis P, Patidar A, Zhang Y, Vilar E, Finkelman M, Farrington K. The Effect of Intra-Dialytic Exercise on Inflammation and Blood Endotoxin Levels. Blood Purif 2017; 44:51-59. [DOI: 10.1159/000455059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/12/2016] [Indexed: 11/19/2022]
Abstract
Background: In healthy individuals, an acute inflammatory response occurs after intense exercise due to gut ischaemia and intestinal bacterial endotoxin translocation into the bloodstream. This process maybe exacerbated in patients who exercise during dialysis due to large volume shifts experienced by many during haemodialysis (HD). The acute effect of intra-dialytic exercise on blood endotoxins and inflammation is not known. Method: The effect of intra-dialytic exercise on blood endotoxin and inflammation was investigated in 10 patients and compared with resting haemodialysis. Blood was measured for endotoxin and inflammatory biomarkers before and after dialysis. Result: With the exception of one sample, all samples tested negative for endotoxin. Intra-dialytic exercise attenuated the rise of interleukin-6, tumour necrosis factor-α and high-sensitivity C-reactive protein after the HD procedure. Conclusion: Intra-dialytic exercise was not associated with an observable rise in blood endotoxin, although it may ameliorate the inflammatory effects of the HD procedure. Larger studies are needed to confirm this finding.
Collapse
|
14
|
Wong J, Zhang Y, Patidar A, Vilar E, Finkelman M, Farrington K. Is Endotoxemia in Stable Hemodialysis Patients an Artefact? Limitations of the Limulus Amebocyte Lysate Assay and Role of (1→3)-β-D Glucan. PLoS One 2016; 11:e0164978. [PMID: 27764208 PMCID: PMC5072723 DOI: 10.1371/journal.pone.0164978] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/04/2016] [Indexed: 01/05/2023] Open
Abstract
Background Elevated blood endotoxin levels are frequently reported in the dialysis population and are strongly linked with inflammation, a major predictor of mortality. Virtually all studies have employed the Limulus Amoebocyte Lysate (LAL) assay to detect endotoxin. However this assay is not endotoxin-specific and can be activated by (1→3)-β-glucan (BG), a component of fungal cell walls leading to false positive signals. Very few studies have taken account of this. We examined the influence of BG-based activation of the LAL assay on the detection of endotoxemia in this setting. Method We measured plasma endotoxin levels in 50 hemodialysis patients with and without the use of BG-blocking buffers. These buffers inhibit BG activation of the LAL assay to ensure that any signal detected is endotoxin-specific. Blood samples were measured for BG, interleukin-6 (IL-6), tumor necrosis factor-alfa (TNF-α) to examine the association between endotoxin signals, BG and inflammation. Results Endotoxin signals were detected in 50% of patients. On repeat measurement with a BG-blocking buffer, all detected endotoxin signals were extinguished. No patient had detectable endotoxemia. Plasma BG levels were significantly elevated in 58% of patients and were higher in those with detectable endotoxin signals using the LAL assay without BG-blocking buffers (78vs.54pg/mL;p<0.001). Endotoxin signal and BG levels did not correlate with levels of TNF-α or IL-6. Conclusion Use of the LAL assay for blood endotoxin detection in dialysis patients has its limitations due to high blood BG. Endotoxemia frequently reported in non-infected hemodialysis patients may be artefactual due to BG interference.
Collapse
Affiliation(s)
- Jonathan Wong
- Lister Renal Unit, Hertfordshire, United Kingdom
- University of Hertfordshire, Hertfordshire, United Kingdom
- * E-mail:
| | - Yonglong Zhang
- Associates of Cape Cod Inc., East Falmouth, Massachusetts, United States of America
| | - Ashish Patidar
- University of Hertfordshire, Hertfordshire, United Kingdom
| | - Enric Vilar
- Lister Renal Unit, Hertfordshire, United Kingdom
- University of Hertfordshire, Hertfordshire, United Kingdom
| | - Malcolm Finkelman
- Associates of Cape Cod Inc., East Falmouth, Massachusetts, United States of America
| | - Ken Farrington
- Lister Renal Unit, Hertfordshire, United Kingdom
- University of Hertfordshire, Hertfordshire, United Kingdom
| |
Collapse
|