scholarly journals Dooming Phagocyte Responses: Inflammatory Effects of Endogenous Oxidized Phospholipids

2021 ◽  
Vol 12 ◽  
Author(s):  
Marco Di Gioia ◽  
Ivan Zanoni

Endogenous oxidized phospholipids are produced during tissue stress and are responsible for sustaining inflammatory responses in immune as well as non-immune cells. Their local and systemic production and accumulation is associated with the etiology and progression of several inflammatory diseases, but the molecular mechanisms that underlie the biological activities of these oxidized phospholipids remain elusive. Increasing evidence highlights the ability of these stress mediators to modulate cellular metabolism and pro-inflammatory signaling in phagocytes, such as macrophages and dendritic cells, and to alter the activation and polarization of these cells. Because these immune cells serve a key role in maintaining tissue homeostasis and organ function, understanding how endogenous oxidized lipids reshape phagocyte biology and function is vital for designing clinical tools and interventions for preventing, slowing down, or resolving chronic inflammatory disorders that are driven by phagocyte dysfunction. Here, we discuss the metabolic and signaling processes elicited by endogenous oxidized lipids and outline new hypotheses and models to elucidate the impact of these lipids on phagocytes and inflammation.

2006 ◽  
Vol 85 (5) ◽  
pp. 404-415 ◽  
Author(s):  
J. Sodek ◽  
A. Paes Batista Da Silva ◽  
R. Zohar

Protection of mucosal tissues of the oral cavity, intestines, respiratory tract, and urogenital tract from the constant challenge of pathogens is achieved by the combined barrier function of the lining epithelia and specialized immune cells. Recent studies have indicated that osteopontin (OPN) has a pivotal role in the development of immune responses and in the tissue destruction and the subsequent repair processes associated with inflammatory diseases. While expression of OPN is increased in immune cells—including neutrophils, macrophages, T- and B-lymphocytes—and in epithelial, endothelial, and fibroblastic cells of inflamed tissues, deciphering the specific functions of OPN has been difficult. In part, this is due to the broad range of biological activities of OPN that are mediated by multiple receptors which recognize several signaling motifs whose activities are influenced by post-translational modifications and proteolytic processing of OPN. Understanding the role of OPN in mucosal inflammation is further complicated by its contributions to the barrier function of the lining epithelia and the complexity of the specialized mucosal immune system. In an attempt to provide some insights into the involvement of OPN in mucosal diseases, this review summarizes current knowledge of the biological activities of OPN involved in the development of inflammatory responses and in wound healing, and indicates how these activities may affect the protection of mucosal tissues.


Author(s):  
Jeongho Park ◽  
Chang H. Kim

AbstractThe gut is connected to the CNS by immunological mediators, lymphocytes, neurotransmitters, microbes and microbial metabolites. A mounting body of evidence indicates that the microbiome exerts significant effects on immune cells and CNS cells. These effects frequently result in the suppression or exacerbation of inflammatory responses, the latter of which can lead to severe tissue damage, altered synapse formation and disrupted maintenance of the CNS. Herein, we review recent progress in research on the microbial regulation of CNS diseases with a focus on major gut microbial metabolites, such as short-chain fatty acids, tryptophan metabolites, and secondary bile acids. Pathological changes in the CNS are associated with dysbiosis and altered levels of microbial metabolites, which can further exacerbate various neurological disorders. The cellular and molecular mechanisms by which these gut microbial metabolites regulate inflammatory diseases in the CNS are discussed. We highlight the similarities and differences in the impact on four major CNS diseases, i.e., multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, and autism spectrum disorder, to identify common cellular and molecular networks governing the regulation of cellular constituents and pathogenesis in the CNS by microbial metabolites.


Author(s):  
Zohreh Jadali

Recent literature has highlighted the importance of chronic inflammation in psoriasis pathogenesis. Non-resolving inflammation can trigger progressive tissue damage and inflammatory mediator release which in turn perpetuate the inflammatory cycle. Under normal conditions, inflammatory responses are tightly controlled through several mechanisms that restore normal tissue function and structure. Defects in regulatory mechanisms of the inflammatory response can result in persistent unresolved inflammation and further increases of inflammation. Therefore, this review focuses on defects in regulatory mechanisms of inflammatory responses that lead to uncontrolled chronic inflammation in psoriasis. Databases such as Pubmed Embase, ISI, and Iranian databases including Iranmedex, and SID were researched to identify relevant literature. The results of this review indicate that dysregulation of the inflammatory response may be a likely cause of various immune-mediated inflammatory disorders such as psoriasis. Based on current findings, advances in understanding the cellular and molecular mechanisms involved in inflammation resolution are not only improving our knowledge of the pathogenesis of chronic inflammatory diseases but also supporting the development of new therapeutic strategies.


Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 372 ◽  
Author(s):  
Karl J. Harber ◽  
Kyra E. de Goede ◽  
Sanne G. S. Verberk ◽  
Elisa Meinster ◽  
Helga E. de Vries ◽  
...  

Immunometabolism revealed the crucial role of cellular metabolism in controlling immune cell phenotype and functions. Macrophages, key immune cells that support progression of numerous inflammatory diseases, have been well described as undergoing vast metabolic rewiring upon activation. The immunometabolite succinate particularly gained a lot of attention and emerged as a crucial regulator of macrophage responses and inflammation. Succinate was originally described as a metabolite that supports inflammation via distinct routes. Recently, studies have indicated that succinate and its receptor SUCNR1 can suppress immune responses as well. These apparent contradictory effects might be due to specific experimental settings and particularly the use of distinct succinate forms. We therefore compared the phenotypic and functional effects of distinct succinate forms and receptor mouse models that were previously used for studying succinate immunomodulation. Here, we show that succinate can suppress secretion of inflammatory mediators IL-6, tumor necrosis factor (TNF) and nitric oxide (NO), as well as inhibit Il1b mRNA expression of inflammatory macrophages in a SUCNR1-independent manner. We also observed that macrophage SUCNR1 deficiency led to an enhanced inflammatory response without addition of exogenous succinate. While our study does not reveal new mechanistic insights into how succinate elicits different inflammatory responses, it does indicate that the inflammatory effects of succinate and its receptor SUCNR1 in macrophages are clearly context dependent.


2012 ◽  
Vol 40 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Gillian R. Milne ◽  
Timothy M. Palmer ◽  
Stephen J. Yarwood

Chronic inflammatory diseases, such as atherosclerosis, are a major cause of death and disability in the developed world. In this respect, although cholesterol obviously plays a predominant role in atherosclerosis, targeting inflammation at lesion sites may be just as important. Indeed, elevated IL-6 (interleukin 6) levels are as strongly associated with coronary heart disease as increased cholesterol. We have been investigating novel cAMP-regulated pathways that combat the action of pro-inflammatory cytokines, such as IL-6 and leptin, in the VECs (vascular endothelial cells) of the circulatory system. In this respect, we have begun to unravel new molecular mechanisms by which the cAMP/Epac1 (exchange protein directly activated by cAMP 1)/Rap1 pathway can initiate a rigorous programme of protective anti-inflammatory responses in VECs. Central to this is the coupling of cAMP elevation to the mobilization of two C/EBP (CCAAT/enhancer-binding protein) family transcription factors, resulting in the induction of the SOCS3 (suppressor of cytokine signalling 3) gene, which attenuates pro-inflammatory cytokine signalling in VECs. These novel ‘protective’ mechanisms of cAMP action will inform the development of the next generation of pharmaceuticals specifically designed to combat endothelial inflammation associated with cardiovascular disease.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mouna Moutia ◽  
Norddine Habti ◽  
Abdallah Badou

Allium Sativum L. (garlic), which is a species of the onion family, Alliaceae, is one of the most used plants in traditional medicine worldwide. More than 200 chemicals with diverse properties have been found in garlic extracts. Several garlic compounds were suggested to be efficient in improving various pathologies including certain types of cancer. This paper is an overview of data about garlic biological activities in vitro and/or in vivo on immune cells, on the development of certain inflammatory diseases, and on different types of carcinomas and sarcomas. Garlic and its compounds were found to have notable antioxidant properties. Garlic therapeutic potential has also been studied in several inflammatory diseases such as allergic-airway inflammation, inflammatory bowel disease, arthritic rheumatism, and atherosclerosis. Furthermore, garlic was found to be able to maintain the immune system homeostasis and to exhibit beneficial effects on immune cells especially through regulation of proliferation and cytokine gene expression. Finally, we will show how major garlic components such as sulfur compounds and polyphenols might be responsible for the garlic biological activities revealed in different situations. If identified, specific compounds present in garlic could potentially be used in therapy.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Qilu Liu ◽  
Shengxiang Xiao ◽  
Yumin Xia

Tumor necrosis factor- (TNF-) like weak inducer of apoptosis (TWEAK) participates in multiple biological activities via binding to its sole receptor—fibroblast growth factor-inducible 14 (Fn14). The TWEAK/Fn14 signaling pathway is activated in skin inflammation and modulates the inflammatory responses of keratinocytes by activating nuclear factor-κB signals and enhancing the production of several cytokines, including interleukins, monocyte chemotactic protein-1, RANTES (regulated on activation, normal T cell expressed and secreted), and interferon gamma-induced protein 10. Mild or transient TWEAK/Fn14 activation contributes to tissular repair and regeneration while excessive or persistent TWEAK/Fn14 signals may lead to severe inflammatory infiltration and tissue damage. TWEAK also regulates cell fate of keratinocytes, involving the function of Fn14-TNF receptor-associated factor-TNF receptor axis. By recruiting inflammatory cells, promoting cytokine production, and regulating cell fate, TWEAK/Fn14 activation plays a pivotal role in the pathogenesis of various skin disorders, such as psoriasis, atopic dermatitis, cutaneous vasculitis, human papillomavirus infection and related skin tumors, and cutaneous autoimmune diseases. Therefore, the TWEAK/Fn14 pathway may be a potential target for the development of novel therapeutics for skin inflammatory diseases.


2015 ◽  
Vol 114 (09) ◽  
pp. 478-789 ◽  
Author(s):  
Waltraud Schrottmaier ◽  
Julia Kral ◽  
Sigrun Badrnya ◽  
Alice Assinger

SummaryPlatelets are key players in haemostasis and represent a pivotal link between inflammation, immunity and atherogenesis. Depending on the (patho)physiological environment platelets modulate various leukocyte functions via release of inflammatory mediators and direct cell-cell interactions. Elevated levels of circulating platelet-leukocyte aggregates are found in patients suffering from several thrombotic or inflammatory conditions. Platelet-monocyte and platelet-neutrophil interaction can trigger pro- and anti-inflammatory responses and modulate effector functions of all leukocyte subpopulations. These platelet-mediated immune responses have implications for the progression of cardiovascular diseases and also play a crucial role during infections, cancer, transplantations and other inflammatory diseases of several organs. Antiplatelet therapy including the COX inhibitor aspirin and/or ADP receptor P2Y12 inhibitors such as clopidogrel, prasugrel and ticagrelor are the therapy of choice for various cardiovascular complications. Both aspirin and P2Y12 inhibitors attenuate platelet-leukocyte interactions, thereby also modulating immune responses. This may have beneficial effects in some pathological conditions, while it might be detrimental in others. This review aims to summarise the current knowledge on platelet-leukocyte interactions and the impact of aspirin and P2Y12 inhibition on platelet-mediated immune responses and to give an overview on the effects of antiplatelet therapy on platelet-leukocyte interplay in various diseases.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1061
Author(s):  
Fabrizia Bonacina ◽  
Angela Pirillo ◽  
Alberico L. Catapano ◽  
Giuseppe D. Norata

High density lipoproteins (HDL) are heterogeneous particles composed by a vast array of proteins and lipids, mostly recognized for their cardiovascular (CV) protective effects. However, evidences from basic to clinical research have contributed to depict a role of HDL in the modulation of immune-inflammatory response thus paving the road to investigate their involvement in other diseases beyond those related to the CV system. HDL-C levels and HDL composition are indeed altered in patients with autoimmune diseases and usually associated to disease severity. At molecular levels, HDL have been shown to modulate the anti-inflammatory potential of endothelial cells and, by controlling the amount of cellular cholesterol, to interfere with the signaling through plasma membrane lipid rafts in immune cells. These findings, coupled to observations acquired from subjects carrying mutations in genes related to HDL system, have helped to elucidate the contribution of HDL beyond cholesterol efflux thus posing HDL-based therapies as a compelling interventional approach to limit the inflammatory burden of immune-inflammatory diseases.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jéssica Aparecida da Silva Pereira ◽  
Felipe Corrêa da Silva ◽  
Pedro Manoel Mendes de Moraes-Vieira

Obesity and insulin resistance have reached epidemic proportions. Obesogenic conditions are associated with increased risk for the development of other comorbidities and obesity-related diseases. In metabolic disorders, there is chronic low-grade inflammation induced by the activation of immune cells, especially in metabolic relevant organs such as white adipose tissue (WAT). These immune cells are regulated by environmental and systemic cues. Ghrelin is a peptide secreted mainly by X/A-like gastric cells and acts through the growth hormone secretagogue receptor (GHS-R). This receptor is broadly expressed in the central nervous system (CNS) and in several cell types, including immune cells. Studies show that ghrelin induces an orexigenic state, and there is increasing evidence implicating an immunoregulatory role for ghrelin. Ghrelin mainly acts on the innate and adaptive immune systems to suppress inflammation and induce an anti-inflammatory profile. In this review, we discuss the immunoregulatory roles of ghrelin, the mechanisms by which ghrelin acts and potential pharmacological applications for ghrelin in the treatment of obesity-associated inflammatory diseases, such as type 2 diabetes (T2D).


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