scholarly journals Acute induction of anomalous and amyloidogenic blood clotting by molecular amplification of highly substoichiometric levels of bacterial lipopolysaccharide

2016 ◽  
Vol 13 (122) ◽  
pp. 20160539 ◽  
Author(s):  
Etheresia Pretorius ◽  
Sthembile Mbotwe ◽  
Janette Bester ◽  
Christopher J. Robinson ◽  
Douglas B. Kell
Keyword(s):  
Inflammatory Diseases ◽  
Isothermal Calorimetry ◽  
Amyloid Β ◽  
Bacterial Lipopolysaccharide ◽  
Primary Role ◽  
Inflammatory Conditions ◽  
Healthy Donors ◽  
Mechanistic Analysis ◽  
Amyloid Diseases

It is well known that a variety of inflammatory diseases are accompanied by hypercoagulability, and a number of more-or-less longer-term signalling pathways have been shown to be involved. In recent work, we have suggested a direct and primary role for bacterial lipopolysaccharide (LPS) in this hypercoagulability, but it seems never to have been tested directly. Here, we show that the addition of tiny concentrations (0.2 ng l −1 ) of bacterial LPS to both whole blood and platelet-poor plasma of normal, healthy donors leads to marked changes in the nature of the fibrin fibres so formed, as observed by ultrastructural and fluorescence microscopy (the latter implying that the fibrin is actually in an amyloid β-sheet-rich form that on stoichiometric grounds must occur autocatalytically). They resemble those seen in a number of inflammatory (and also amyloid) diseases, consistent with an involvement of LPS in their aetiology. These changes are mirrored by changes in their viscoelastic properties as measured by thromboelastography. As the terminal stages of coagulation involve the polymerization of fibrinogen into fibrin fibres, we tested whether LPS would bind to fibrinogen directly. We demonstrated this using isothermal calorimetry. Finally, we show that these changes in fibre structure are mirrored when the experiment is done simply with purified fibrinogen and thrombin (±0.2 ng l −1 LPS). This ratio of concentrations of LPS : fibrinogen in vivo represents a molecular amplification by the LPS of more than 10 8 -fold, a number that is probably unparalleled in biology. The observation of a direct effect of such highly substoichiometric amounts of LPS on both fibrinogen and coagulation can account for the role of very small numbers of dormant bacteria in disease progression in a great many inflammatory conditions, and opens up this process to further mechanistic analysis and possible treatment.

scholarly journals Acute induction of anomalous blood clotting by molecular amplification of highly substoichiometric levels of bacterial lipopolysaccharide (LPS)

2016 ◽  
Author(s):  
Etheresia Pretorius ◽  
Sthembile Mbotwa ◽  
Janette Bester ◽  
Christopher Robinson ◽  
Douglas B. Kell
Keyword(s):  
Inflammatory Diseases ◽  
Isothermal Calorimetry ◽  
Amyloid Β ◽  
Bacterial Lipopolysaccharide ◽  
Primary Role ◽  
Low Concentrations ◽  
Healthy Donors ◽  
Mechanistic Analysis ◽  
Direct Binding

ABSTRACTIt is well known that a variety of inflammatory diseases are accompanied by hypercoagulability, and a number of more-or-less longer-term signalling pathways have been shown to be involved. In recent work, we have suggested a direct and primary role for bacterial lipopolysaccharide in this hypercoagulability, but it seems never to have been tested directly. Here we show that the addition of tiny concentrations (0.2 ng.L−1) of bacterial lipopolysaccharide (LPS) to both whole blood and platelet-poor plasma of normal, healthy donors leads to marked changes in the nature of the fibrin fibres so formed, as observed by ultrastructural and fluorescence microscopy (the latter implying that the fibrin is actually in an amyloid β-sheet-rich form. They resemble those seen in a number of inflammatory (and also amyloid) diseases, consistent with an involvement of LPS in their aetiology. These changes are mirrored by changes in their viscoelastic properties as measured by thromboelastography. Since the terminal stages of coagulation involve the polymerisation of fibrinogen into fibrin fibres, we tested whether LPS would bind to fibrinogen directly. We demonstrated this using isothermal calorimetry. Finally, we show that these changes in fibre structure are mirrored when the experiment is done simply with purified fibrinogen and thrombin (± 0.2 ng.L−1LPS). This ratio of concentrations of LPS:fibrinogenin vivorepresents a molecular amplification by the LPS of more than 108-fold, a number that is probably unparalleled in biology. The observation of a direct effect of such highly substoichiometric amounts of LPS on both fibrinogen and coagulation can account for the role of very small numbers of dormant bacteria in disease progression, and opens up this process to further mechanistic analysis and possible treatment.Significance statementMost chronic diseases (including those classified as cardiovascular, neurodegenerative, or autoimmune) are accompanied by long-term inflammation. Although typically mediated by ‘inflammatory’ cytokines, the origin of this inflammation is unclear. We have suggested that one explanation is a dormant microbiome that can shed the highly inflammatory lipopolysaccharide LPS. Such inflammatory diseases are also accompanied by a hypercoagulable phenotype. We here showdirectly(using 6 different methods) that very low concentrations of LPS can affect the terminal stages of the coagulation properties of blood and plasma significantly, and that this may be mediated via a direct binding of LPS to a small fraction of fibrinogen monomers as assessed biophysically. Such amplification methods may be of more general significance.

Insights into amyloid disease from fly models

2014 ◽  
Vol 56 ◽  
pp. 69-83 ◽  
Author(s):  
Ko-Fan Chen ◽  
Damian C. Crowther
Keyword(s):  
Drosophila Melanogaster ◽  
Neurodegenerative Disorders ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Disease Pathogenesis ◽  
Amyloid Aggregates ◽  
Aβ Amyloid ◽  
Polypeptide Chains ◽  
Amyloid Diseases

The formation of amyloid aggregates is a feature of most, if not all, polypeptide chains. In vivo modelling of this process has been undertaken in the fruitfly Drosophila melanogaster with remarkable success. Models of both neurological and systemic amyloid diseases have been generated and have informed our understanding of disease pathogenesis in two main ways. First, the toxic amyloid species have been at least partially characterized, for example in the case of the Aβ (amyloid β-peptide) associated with Alzheimer's disease. Secondly, the genetic underpinning of model disease-linked phenotypes has been characterized for a number of neurodegenerative disorders. The current challenge is to integrate our understanding of disease-linked processes in the fly with our growing knowledge of human disease, for the benefit of patients.

Cerebrospinal fluid biomarkers of β-amyloid metabolism in multiple sclerosis

2012 ◽  
Vol 19 (5) ◽  
pp. 543-552 ◽  
Author(s):  
Kristin Augutis ◽  
Markus Axelsson ◽  
Erik Portelius ◽  
Gunnar Brinkmalm ◽  
Ulf Andreasson ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Cerebrospinal Fluid ◽  
Inflammatory Diseases ◽  
Amyloid Β ◽  
Csf Biomarkers ◽  
Aβ Peptide ◽  
Aβ Peptides ◽  
App Metabolism ◽  
Disease Modifying

Background: Amyloid precursor protein (APP) and amyloid β (Aβ) peptides are intensely studied in neuroscience and their cerebrospinal fluid (CSF) measurements may be used to track the metabolic pathways of APP in vivo. Reduced CSF levels of Aβ and soluble APP (sAPP) fragments are reported in inflammatory diseases, including multiple sclerosis (MS); but in MS, the precise pathway of APP metabolism and whether it can be affected by disease-modifying treatments remains unclear. Objective: To characterize the CSF biomarkers of APP degradation in MS, including the effects of disease-modifying therapy. Methods: CSF samples from 87 MS patients (54 relapsing–remitting (RR) MS; 33 secondary progressive (SP) MS and 28 controls were analyzed for sAPP and Aβ peptides by immunoassays, plus a subset of samples was analyzed by immunoprecipitation and mass spectrometry (IP-MS). Patients treated with natalizumab or mitoxantrone were examined at baseline, and after 1–2 years of treatment. Results: CSF sAPP and Aβ peptide levels were reduced in MS patients; but they increased again towards normal, after natalizumab treatment. A multivariate model of IP-MS-measured Aβ species separated the SPMS patients from controls, with RRMS patients having intermediate levels. Conclusions: We confirmed and extended our previous observations of altered CSF sAPP and Aβ peptide levels in MS patients. We found that natalizumab therapy may be able to counteract the altered APP metabolism in MS. The CSF Aβ isoform distribution was found to be distinct in SPMS patients, as compared to the controls.

scholarly journals The effects of 5-hydroxytryptophan on carrageenan-induced mouse paw oedemas

2021 ◽  
Vol 34 ◽  
Author(s):  
Gokçen TELLI ◽  
Inci KAZKAYASI ◽  
Serdar UMA
Keyword(s):  
Oral Absorption ◽  
Inflammatory Diseases ◽  
Food Supplement ◽  
Peripheral Inflammation ◽  
Independent Manner ◽  
Inflammatory Conditions ◽  
Paw Oedema ◽  
Serotonin Biosynthesis ◽  
Oral Doses

ABSTRACT Objective 5-Hydroxytryptophan is the precursor compound of serotonin biosynthesis. The oral absorption of 5-Hydroxytryptophan is close to 100% and, unlike serotonin, it crosses the blood-brain barrier freely. 5-Hydroxytryptophan has been used as a food supplement for many years to treat anxiety and depression. Recent studies have shown that 5-Hydroxytryptophan suppresses the pro-inflammatory mediators and is effective in some inflammatory diseases, such as arthritis and allergic asthma. However, the role of 5-Hydroxytryptophan supplements on acute peripheral inflammation has not been investigated yet. In this study, the in vivo anti-inflammatory activity of 5-Hydroxytryptophan was evaluated with a carrageenan-induced paw oedema test in mice. Methods For the investigation of the acute antiinflammatory activity, single oral doses of 5-Hydroxytryptophan (1.5, 5 and 20mg/kg) were given to mice 1.5 hours prior to the carrageenan test. For chronic activity, the same oral doses were administered daily for two weeks prior to the carrageenan test on the 14th day. To induce inflammation, 0.01mL of 2% carrageenan was injected into the paws of mice. Results Supplementation with 5-Hydroxytryptophan significantly reduced inflammation in a dose-independent manner which was irrespective of the duration of exposure (per cent inhibition in acute experiments was 35.4%, 20.9%, 24.0%, and per cent inhibition in chronic experiments was 29.5%, 35.3%, 40.8% for the doses of 1.5, 5, and 20mg/kg, respectively). Conclusion Our findings demonstrate for the first time that 5-HTP supplements have the potential of suppressing the measures of acute peripheral inflammation. It is suggested that, apart from several diseases where serotonin is believed to play an important role, including depression, patients with inflammatory conditions may also benefit from 5-HTP.

A novel TNFR2 agonist antibody expands highly potent regulatory T cells

2020 ◽  
Vol 13 (661) ◽  
pp. eaba9600
Author(s):  
Heather Torrey ◽  
Willem M. Kühtreiber ◽  
Yoshiaki Okubo ◽  
Lisa Tran ◽  
Katherine Case ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cell Expansion ◽  
Inflammatory Diseases ◽  
Tumor Necrosis Factor Receptor ◽  
Maximal Activity ◽  
Cross Linking ◽  
Healthy Donors ◽  
Metabolic Gene Expression

Regulatory T cells (Treg cells) restrict immune system activity, such as in response to self-antigens, and are switched on by tumor necrosis factor receptor 2 (TNFR2). Therapeutic activation of TNFR2, thereby expanding Treg cells and suppressing immune activity, may be beneficial to patients with various inflammatory diseases. Here, we characterized a new human TNFR2-directed antibody agonist isolated from mice. We found that the antibody agonist expanded the number of Treg cells within cultures of primary human CD4+ T cells from healthy donors and patients with type 1 diabetes or Sézary syndrome. These Treg cells had increased metabolic gene expression and intracellular itaconate concentrations, characteristics associated with maximally suppressive, anti-inflammatory Treg cells. Furthermore, antibody-expanded Treg cells repressed the activity of primary human CD8+ effector T cells (Teff cells). Epitope mapping suggested that the antibody bound to TNFR2 through a natural cross-linking surface and that Treg cell expansion was independent of the antibody Fc region. In addition, Treg cell expansion was not increased by adding either supplemental TNF ligand or a cross-linking reagent, suggesting that the antibody agonist by itself can elicit maximal activity, a notion that was confirmed by increased secretion of soluble TNFR2. Pending in vivo tests, these features indicate that this TNFR2 antibody agonist has the potential to safely and effectively treat various inflammatory disorders.

The CX3C-Chemokine Fractalkine (CX3CL1) is Detectable in Serum of Patients Affected by the Inflammatory Diseases Allergic Rhinitis and/or Asthma

2005 ◽  
Vol 3 (3) ◽  
pp. 149-152
Author(s):  
P.L. Minciullo ◽  
M. Patafi ◽  
L. Giannetto ◽  
R.A. Merendino ◽  
G. Di Pasquale ◽  
...  
Keyword(s):  
Allergic Rhinitis ◽  
Potential Role ◽  
Inflammatory Diseases ◽  
Allergic Diseases ◽  
Serum Levels ◽  
Airway Disease ◽  
High Serum ◽  
Allergic Airway Disease ◽  
Inflammatory Conditions ◽  
Healthy Donors

Fractalkine (FKN) is a chemokine able to mediate the initial capture, firm adhesion, and activation of circulating leukocytes. Many tissues express FKN mRNA and FKN expression is increased during inflammatory conditions. To assess a possible involvement in allergic airway disease, we detected serum levels of FKN in a group of patients affected by allergic rhinitis and/or asthma and found high serum levels of FKN in all patients and in only 26% of healthy donors at lower concentrations. The present results underscore the potential role that this chemokine may play in the pathogenesis of respiratory allergic diseases.

scholarly journals Essential Oils and Their Major Compounds in the Treatment of Chronic Inflammation: A Review of Antioxidant Potential in Preclinical Studies and Molecular Mechanisms

2018 ◽  
Vol 2018 ◽  
pp. 1-23 ◽  
Author(s):  
Érica Martins de Lavor ◽  
Antônio Wilton Cavalcante Fernandes ◽  
Roxana Braga de Andrade Teles ◽  
Ana Ediléia Barbosa Pereira Leal ◽  
Raimundo Gonçalves de Oliveira Júnior ◽  
...  
Keyword(s):  
Essential Oils ◽  
Chronic Inflammation ◽  
Molecular Mechanisms ◽  
Inflammatory Diseases ◽  
Biologically Active ◽  
Preclinical Studies ◽  
Inflammatory Conditions ◽  
Potential Activity

Inflammatory diseases result from the body’s response to tissue damage, and if the resolution is not adequate or the stimulus persists, there will be progression from acute inflammation to chronic inflammation, leading to the development of cancer and neurodegenerative and autoimmune diseases. Due to the complexity of events that occur in inflammation associated with the adverse effects of drugs used in clinical practice, it is necessary to search for new biologically active compounds with anti-inflammatory activity. Among natural products, essential oils (EOs) present promising results in preclinical studies, with action in the main mechanisms involved in the pathology of inflammation. The present systematic review summarizes the pharmacological effects of EOs and their compounds in in vitro and in vivo models for inflammation. The research was conducted in the following databases: PubMed, Scopus, BIREME, Scielo, Open Grey, and Science Direct. Based on the inclusion criteria, 30 articles were selected and discussed in this review. The studies listed revealed a potential activity of EOs and their compounds for the treatment of inflammatory diseases, especially in chronic inflammatory conditions, with the main mechanism involving reduction of reactive oxygen and nitrogen species associated with an elevation of antioxidant enzymes as well as the reduction of the nuclear factor kappa B (NF-κB), reducing the expression of proinflammatory cytokines. Thus, this review suggests that EOs and their major compounds are promising tools for the treatment of chronic inflammation.

scholarly journals Therapeutic Role of miR-30a in Lipoteichoic Acid-Induced Endometritis via Targeting the MyD88/Nox2/ROS Signaling

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Kangfeng Jiang ◽  
Weiqi Ye ◽  
Qian Bai ◽  
Jinyin Cai ◽  
Haichong Wu ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Lipoteichoic Acid ◽  
In Vivo Studies ◽  
Economic Losses ◽  
Inflammatory Conditions ◽  
Wide Range

Staphylococcus aureus (S. aureus), a notorious pathogenic bacterium prevalent in the environment, causes a wide range of inflammatory diseases such as endometritis. Endometritis is an inflammatory disease in humans and mammals, which prolongs uterine involution and causes great economic losses. MiR-30a plays an importan trole in the process of inflammation; however, the regulatory role of miR-30a in endometritis is still unknown. Here, we first noticed that there was an increased level of miR-30a in uterine samples of cows with endometritis. And then, bovine endometrial epithelial (BEND) cells stimulated with the virulence factor lipoteichoic acid (LTA) from S. aureus were used as an in vitro endometritis model to explore the potential role of miR-30a in the pathogenesis of endometritis. Our data showed that the induction of the miR-30a expression is dependent on NF-κB activation, and its overexpression significantly decreased the levels of IL-1β and IL-6. Furthermore, we observed that the overexpression of miR-30a inhibited its translation by binding to 3 ′ − UTR of MyD88 mRNA, thus preventing the activation of Nox2 and NF-κB and ROS accumulation. Meanwhile, in vivo studies further revealed that upregulation of miR-30a using chemically synthesized agomirs alleviates the inflammatory conditions in an experimental mouse model of endometritis, as indicated by inhibition of ROS and NF-κB. Taken together, these findings highlight that miR-30a can attenuate LTA-elicited oxidative stress and inflammatory responses through the MyD88/Nox2/ROS/NF-κB pathway and may aid the future development of novel therapies for inflammatory diseases caused by S. aureus, including endometritis.

scholarly journals MerTK cleavage limits proresolving mediator biosynthesis and exacerbates tissue inflammation

2016 ◽  
Vol 113 (23) ◽  
pp. 6526-6531 ◽  
Author(s):  
Bishuang Cai ◽  
Edward B. Thorp ◽  
Amanda C. Doran ◽  
Manikandan Subramanian ◽  
Brian E. Sansbury ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Inflammatory Diseases ◽  
Ischemia Reperfusion ◽  
Genetically Engineered ◽  
Sterile Inflammation ◽  
Long Chain Fatty Acid ◽  
Inflammatory Conditions ◽  
Remote Organ ◽  
Inflammation Resolution

The acute inflammatory response requires a coordinated resolution program to prevent excessive inflammation, repair collateral damage, and restore tissue homeostasis, and failure of this response contributes to the pathology of numerous chronic inflammatory diseases. Resolution is mediated in part by long-chain fatty acid-derived lipid mediators called specialized proresolving mediators (SPMs). However, how SPMs are regulated during the inflammatory response, and how this process goes awry in inflammatory diseases, are poorly understood. We now show that signaling through the Mer proto-oncogene tyrosine kinase (MerTK) receptor in cultured macrophages and in sterile inflammation in vivo promotes SPM biosynthesis by a mechanism involving an increase in the cytoplasmic:nuclear ratio of a key SPM biosynthetic enzyme, 5-lipoxygenase. This action of MerTK is linked to the resolution of sterile peritonitis and, after ischemia–reperfusion (I/R) injury, to increased circulating SPMs and decreased remote organ inflammation. MerTK is susceptible to ADAM metallopeptidase domain 17 (ADAM17)-mediated cell-surface cleavage under inflammatory conditions, but the functional significance is not known. We show here that SPM biosynthesis is increased and inflammation resolution is improved in a new mouse model in which endogenous MerTK was replaced with a genetically engineered variant that is cleavage-resistant (MertkCR). MertkCR mice also have increased circulating levels of SPMs and less lung injury after I/R. Thus, MerTK cleavage during inflammation limits SPM biosynthesis and the resolution response. These findings contribute to our understanding of how SPM synthesis is regulated during the inflammatory response and suggest new therapeutic avenues to boost resolution in settings where defective resolution promotes disease progression.

scholarly journals Thawed Mesenchymal Stem Cell Product Shows Comparable Immunomodulatory Potency to Cultured Cells In Vitro and in Polymicrobial Septic Animals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuan Tan ◽  
Mahmoud Salkhordeh ◽  
Jia-Pey Wang ◽  
Andrea McRae ◽  
Luciana Souza-Moreira ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Inflammatory Diseases ◽  
Endothelial Permeability ◽  
Innate Immune ◽  
Activated T Cells ◽  
Inflammatory Conditions ◽  
Significant Difference ◽  
Stem Cell Product

AbstractMesenchymal stem cells (MSCs) have been shown to exert immunomodulatory effects in both acute and chronic diseases. In acute inflammatory conditions like sepsis, cell therapy must be administered within hours of diagnosis, requiring “off-the-shelf” cryopreserved allogeneic cell products. However, their immunomodulatory potency, particularly in abilities to modulate innate immune cells, has not been well documented. Herein we compared the stabilities and functionalities of cultured versus thawed, donor-matched MSCs in modulating immune responses in vitro and in vivo. Cultured and thawed MSCs exhibited similar surface marker profiles and viabilities at 0 hr; however, thawed MSCs exhibited higher levels of apoptotic cells beyond 4 hrs. In vitro potency assays showed no significant difference between the abilities of both MSCs (donor-matched) to suppress proliferation of activated T cells, enhance phagocytosis of monocytes, and restore endothelial permeability after injury. Most importantly, in animals with polymicrobial sepsis, both MSCs significantly improved the phagocytic ability of peritoneal lavage cells, and reduced plasma levels of lactate and selected inflammatory cytokines without significant difference between groups. These results show comparable in vitro and in vivo immunomodulatory efficacy of thawed and fresh MSC products, providing further evidence for the utility of a cryopreserved MSC product for acute inflammatory diseases.

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