37 research outputs found
Epigenetic Modifications of the Nuclear Factor Kappa B Signalling Pathway and its Impact on Inflammatory Bowel Disease
Review article: impact of cigarette smoking on intestinal inflammation-direct and indirect mechanisms
Can harmonisation of outcomes bridge the translation gap for pre-clinical research? A systematic review of outcomes measured in mouse models of type 2 diabetes
Background:
In pre-clinical research, systematic reviews have the potential to mitigate translational challenges by facilitating understanding of how pre-clinical studies can inform future clinical research. Yet their conduct is encumbered by heterogeneity in the outcomes measured and reported, and those outcomes may not always relate to the most clinically important outcomes. We aimed to systematically review outcomes measured and reported in pre-clinical in vivo studies of pharmacological interventions to treat high blood glucose in mouse models of type 2 diabetes.
Methods:
A systematic review of pre-clinical in vivo studies of pharmacological interventions aimed at addressing elevated blood glucose in mouse models of type 2 diabetes was completed. Studies were screened for eligibility and outcomes extracted from the included studies. The outcomes were recorded verbatim and classified into outcome domains using an existing outcome taxonomy. Outcomes were also compared to those identified in a systematic review of registered phase 3/4 clinical trials for glucose lowering interventions in people with type 2 diabetes.
Results:
Review of 280 included studies identified 532 unique outcomes across 19 domains. No single outcome, or domain, was measured in all studies and only 132 (21%) had also been measured in registered phase 3/4 clinical trials. A core outcome set, representing the minimum that should be measured and reported, developed for type 2 diabetes effectiveness clinical trials includes 18 core outcomes, of these 12 (71%) outcomes were measured and reported in one or more of the included pre-clinical studies.
Conclusions:
There is heterogeneity of outcomes reported in pre-clinical research. Harmonisation of outcomes across the research pathway using a core outcome set may facilitate interpretation, evidence synthesis and translational success, and may contribute to the refinement of the use of animals in research.
Systematic review registration: The study was prospectively registered on the PROSPERO Database, registration number CRD4201810683
The Generation of an Engineered Interleukin-10 Protein With Improved Stability and Biological Function
Interleukin-10 (IL-10) is an immunoregulatory cytokine that plays a pivotal role in modulating inflammation. IL-10 has inhibitory effects on proinflammatory cytokine production and function in vitro and in vivo; as such, IL-10 is viewed as a potential treatment for various inflammatory diseases. However, a significant drawback of using IL-10 in clinical application is the fact that the biologically active form of IL-10 is an unstable homodimer, which has a short half-life and is easily degraded in vivo. Consequently, IL-10 therapy using recombinant native IL-10 has had only limited success in the treatment of human disease. To improve the therapeutic potential of IL-10, we have generated a novel form of IL-10, which consists of two IL-10 monomer subunits linked in a head to tail fashion by a flexible linker. We show that the linker length per se did not affect the expression and biological activity of the stable IL-10 molecule, which was more active than natural IL-10, both in vitro and in vivo. We confirmed that the new form of IL-10 had a much-improved temperature- and pH-dependent biological stability compared to natural IL-10. The IL-10 dimer protein binds to the IL-10 receptor similarly to the natural IL-10 protein, as shown by antibody blocking and through the genetic modifications of one monomer in the IL-10 dimer specifically at the IL-10 receptor binding site. Finally, we showed that stable IL-10 is more effective at suppressing LPS-induced-inflammation in vivo compared to the natural IL-10. In conclusion, we have developed a new stable dimer version of the IL-10 protein with improved stability and efficacy to suppress inflammation. We propose that this novel stable IL-10 dimer could serve as the basis for the development of targeted anti-inflammatory drugs
Experimental Models to Study Immune Dysfunction in the Pathogenesis of Parkinson’s Disease
Parkinson’s disease (PD) is a chronic, age-related, progressive multisystem disease associated with neuroinflammation and immune dysfunction. This review discusses the methodological approaches used to study the changes in central and peripheral immunity in PD, the advantages and limitations of the techniques, and their applicability to humans. Although a single animal model cannot replicate all pathological features of the human disease, neuroinflammation is present in most animal models of PD and plays a critical role in understanding the involvement of the immune system (IS) in the pathogenesis of PD. The IS and its interactions with different cell types in the central nervous system (CNS) play an important role in the pathogenesis of PD. Even though culture models do not fully reflect the complexity of disease progression, they are limited in their ability to mimic long-term effects and need validation through in vivo studies. They are an indispensable tool for understanding the interplay between the IS and the pathogenesis of this disease. Understanding the immune-mediated mechanisms may lead to potential therapeutic targets for the treatment of PD. We believe that the development of methodological guidelines for experiments with animal models and PD patients is crucial to ensure the validity and consistency of the results
NF-κB1 Inhibits TLR-Induced IFN-β Production in Macrophages Through TPL-2-dependent ERK Activation
available in PMC 2012 February 15.Although NF-κB1 p50/p105 has critical roles in immunity, the mechanism by which NF-κB1 regulates inflammatory responses is unclear. In this study, we analyzed the gene expression profile of LPS-stimulated Nfkb1−/− macrophages that lack both p50 and p105. Deficiency of p50/p105 selectively increased the expression of IFN-responsive genes, which correlated with increased IFN-β expression and STAT1 phosphorylation. IFN Ab-blocking experiments indicated that increased STAT1 phosphorylation and expression of IFN-responsive genes observed in the absence of p50/p105 depended upon autocrine IFN-β production. Markedly higher serum levels of IFN-β were observed in Nfkb1−/− mice than in wild-type mice following LPS injection, demonstrating that Nfkb1 inhibits IFN-β production under physiological conditions. TPL-2, a mitogen-activated protein kinase kinase kinase stabilized by association with the C-terminal ankyrin repeat domain of p105, negatively regulates LPS-induced IFN-β production by macrophages via activation of ERK MAPK. Retroviral expression of TPL-2 in Nfkb1−/− macrophages, which are deficient in endogenous TPL-2, reduced LPS-induced IFN-β secretion. Expression of the C-terminal ankyrin repeat domain of p105 in Nfkb1−/− macrophages, which rescued LPS activation of ERK, also inhibited IFN-β expression. These data indicate that p50/p105 negatively regulates LPS-induced IFN signaling in macrophages by stabilizing TPL-2, thereby facilitating activation of ERK.National Institutes of Health (U.S.) (NIH AI52267)National Institutes of Health (U.S.) (NIH CA108854)National Institutes of Health (U.S.) (NIH CA67529)Medical Research Council (Great Britain
Netazepide inhibits expression of Pappalysin 2 in type-1 gastric neuroendocrine tumors
Background & Aims: In patients with autoimmune atrophic gastritis and achlorhydria, hypergastrinemia is associated with the development of type 1 gastric neuroendocrine tumors (gNETs). Twelve months of treatment with netazepide (YF476), an antagonist of the cholecystokinin B receptor (CCKBR or CCK2R), eradicated some type 1 gNETs in patients. We investigated the mechanisms by which netazepide induced gNET regression using gene expression profiling. Methods: We obtained serum samples and gastric corpus biopsy specimens from 8 patients with hypergastrinemia and type 1 gNETs enrolled in a phase 2 trial of netazepide. Control samples were obtained from 10 patients without gastric cancer. We used amplified and biotinylated sense-strand DNA targets from total RNA and Affymetrix (Thermofisher Scientific, UK) Human Gene 2.0 ST microarrays to identify differentially expressed genes in stomach tissues from patients with type 1 gNETs before, during, and after netazepide treatment. Findings were validated in a human AGS GR gastric adenocarcinoma cell line that stably expresses human CCK2R, primary mouse gastroids, transgenic hypergastrinemic INS-GAS mice, and patient samples. Results: Levels of pappalysin 2 (PAPPA2) messenger RNA were reduced significantly in gNET tissues from patients receiving netazepide therapy compared with tissues collected before therapy. PAPPA2 is a metalloproteinase that increases the bioavailability of insulin-like growth factor (IGF) by cleaving IGF binding proteins (IGFBPs). PAPPA2 expression was increased in the gastric corpus of patients with type 1 gNETs, and immunohistochemistry showed localization in the same vicinity as CCK2R-expressing enterochromaffin-like cells. Up-regulation of PAPPA2 also was found in the stomachs of INS-GAS mice. Gastrin increased PAPPA2 expression with time and in a dose-dependent manner in gastric AGS GR cells and mouse gastroids by activating CCK2R. Knockdown of PAPPA2 in AGS GR cells with small interfering RNAs significantly decreased their migratory response and tissue remodeling in response to gastrin. Gastrin altered the expression and cleavage of IGFBP3 and IGFBP5. Conclusions: In an analysis of human gNETS and mice, we found that gastrin up-regulates the expression of gastric PAPPA2. Increased PAPPA2 alters IGF bioavailability, cell migration, and tissue remodeling, which are involved in type 1 gNET development. These effects are inhibited by netazepide
Post-COVID-19 Parkinsonism and Parkinson's Disease Pathogenesis: The Exosomal Cargo Hypothesis
Parkinson's disease (PD) is the second most prevalent neurodegenerative disease after Alzheimer's disease, globally. Dopaminergic neuron degeneration in substantia nigra pars compacta and aggregation of misfolded alpha-synuclein are the PD hallmarks, accompanied by motor and non-motor symptoms. Several viruses have been linked to the appearance of a post-infection parkinsonian phenotype. Coronavirus disease 2019 (COVID-19), caused by emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, has evolved from a novel pneumonia to a multifaceted syndrome with multiple clinical manifestations, among which neurological sequalae appear insidious and potentially long-lasting. Exosomes are extracellular nanovesicles bearing a complex cargo of active biomolecules and playing crucial roles in intercellular communication under pathophysiological conditions. Exosomes constitute a reliable route for misfolded protein transmission, contributing to PD pathogenesis and diagnosis. Herein, we summarize recent evidence suggesting that SARS-CoV-2 infection shares numerous clinical manifestations and inflammatory and molecular pathways with PD. We carry on hypothesizing that these similarities may be reflected in exosomal cargo modulated by the virus in correlation with disease severity. Travelling from the periphery to the brain, SARS-CoV-2-related exosomal cargo contains SARS-CoV-2 RNA, viral proteins, inflammatory mediators, and modified host proteins that could operate as promoters of neurodegenerative and neuroinflammatory cascades, potentially leading to a future parkinsonism and PD development
TPL-2 negatively regulates interferon-β production in macrophages and myeloid dendritic cells
Stimulation of Toll-like receptors (TLRs) on macrophages and dendritic cells (DCs) by pathogen-derived products induces the production of cytokines, which play an important role in immune responses. Here, we investigated the role of the TPL-2 signaling pathway in TLR induction of interferon-β (IFN-β) and interleukin-10 (IL-10) in these cell types. It has previously been suggested that IFN-β and IL-10 are coordinately regulated after TLR stimulation. However, in the absence of TPL-2 signaling, lipopolysaccharide (TLR4) and CpG (TLR9) stimulation resulted in increased production of IFN-β while decreasing IL-10 production by both macrophages and myeloid DCs. In contrast, CpG induction of both IFN-α and IFN-β by plasmacytoid DCs was decreased in the absence of TPL-2, although extracellular signal-regulated kinase (ERK) activation was blocked. Extracellular signal-related kinase–dependent negative regulation of IFN-β in macrophages was IL-10–independent, required protein synthesis, and was recapitulated in TPL-2–deficient myeloid DCs by retroviral transduction of the ERK-dependent transcription factor c-fos