scholarly journals The Anti-Inflammatory Properties of Phytochemicals and Their Effects on Epigenetic Mechanisms Involved in TLR4/NF-κB-Mediated Inflammation

2021 ◽  
Vol 12 ◽  
Author(s):  
Haidy A. Saleh ◽  
Mohamed H. Yousef ◽  
Anwar Abdelnaser

Innate immune response induces positive inflammatory transducers and regulators in order to attack pathogens, while simultaneously negative signaling regulators are transcribed to maintain innate immune homeostasis and to avoid persistent inflammatory immune responses. The gene expression of many of these regulators is controlled by different epigenetic modifications. The remarkable impact of epigenetic changes in inducing or suppressing inflammatory signaling is being increasingly recognized. Several studies have highlighted the interplay of histone modification, DNA methylation, and post-transcriptional miRNA-mediated modifications in inflammatory diseases, and inflammation-mediated tumorigenesis. Targeting these epigenetic alterations affords the opportunity of attenuating different inflammatory dysregulations. In this regard, many studies have identified the significant anti-inflammatory properties of distinct naturally-derived phytochemicals, and revealed their regulatory capacity. In the current review, we demonstrate the signaling cascade during the immune response and the epigenetic modifications that take place during inflammation. Moreover, we also provide an updated overview of phytochemicals that target these mechanisms in macrophages and other experimental models, and go on to illustrate the effects of these phytochemicals in regulating epigenetic mechanisms and attenuating aberrant inflammation.

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Kristina Ritter ◽  
Jan Christian Sodenkamp ◽  
Alexandra Hölscher ◽  
Jochen Behrends ◽  
Christoph Hölscher

Anti-inflammatory treatment of chronic inflammatory diseases often increases susceptibility to infectious diseases such as tuberculosis (TB). Since numerous chronic inflammatory and autoimmune diseases are mediated by interleukin (IL)-6-induced T helper (TH) 17 cells, a TH17-directed anti-inflammatory therapy may be preferable to an IL-12-dependent TH1 inhibition in order to avoid reactivation of latent infections. To assess, however, the risk of inhibition of IL-6-dependent TH17-mediated inflammation, we examined the TH17 immune response and the course of experimental TB in IL-6- and T-cell-specific gp130-deficient mice. Our study revealed that the absence of IL-6 or gp130 on T cells has only a minor effect on the development of antigen-specific TH1 and TH17 cells. Importantly, these gene-deficient mice were as capable as wild type mice to control mycobacterial infection. Together, in contrast to its key function for TH17 development in other inflammatory diseases, IL-6 plays an inferior role for the generation of TH17 immune responses during experimental TB.


Glycobiology ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 134-142 ◽  
Author(s):  
María V Tribulatti ◽  
Julieta Carabelli ◽  
Cecilia A Prato ◽  
Oscar Campetella

Abstract Galectins (Gals), a family of mammalian lectins, have emerged as key regulators of the immune response, being implicated in several physiologic and pathologic conditions. Lately, there is increasing data regarding the participation of Galectin-8 (Gal-8) in both the adaptive and innate immune responses, as well as its high expression in inflammatory disorders. Here, we focus on the pro- and anti-inflammatory properties of Gal-8 and discuss the potential use of this lectin in order to shape the immune response, according to the context.


Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 284 ◽  
Author(s):  
Benjamin J. Swartzwelter ◽  
Francesco Barbero ◽  
Alessandro Verde ◽  
Maria Mangini ◽  
Marinella Pirozzi ◽  
...  

Innate immune memory is characterized by a modulation in the magnitude with which innate immune cells such as monocytes and macrophages respond to potential dangers, subsequent to previous exposure to the same or unrelated agents. In this study, we have examined the capacity of gold nanoparticles (AuNP), which are already in use for therapeutic and diagnostic purposes, to modulate the innate memory induced by bacterial agents. The induction of innate memory was achieved in vitro by exposing human primary monocytes to bacterial agents (lipopolysaccharide -LPS-, or live Bacille Calmette-Guérin -BCG) in the absence or presence of AuNP. After the primary activation, cells were allowed to return to a resting condition, and eventually re-challenged with LPS. The induction of memory was assessed by comparing the response to the LPS challenge of unprimed cells with that of cells primed with bacterial agents and AuNP. The response to LPS was measured as the production of inflammatory (TNFα, IL-6) and anti-inflammatory cytokines (IL-10, IL-1Ra). While ineffective in directly inducing innate memory per se, and unable to influence LPS-induced tolerance memory, AuNP significantly affected the memory response of BCG-primed cells, by inhibiting the secondary response in terms of both inflammatory and anti-inflammatory factor production. The reprogramming of BCG-induced memory towards a tolerance type of reactivity may open promising perspectives for the use of AuNP in immunomodulatory approaches to autoimmune and chronic inflammatory diseases.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1004
Author(s):  
Carla van Alem ◽  
Josbert Metselaar ◽  
Cees van Kooten ◽  
Joris Rotmans

Liposomes can be seen as ideal carriers for anti-inflammatory drugs as their ability to (passively) target sites of inflammation and release their content to inflammatory target cells enables them to increase local efficacy with only limited systemic exposure and adverse effects. Nonetheless, few liposomal formulations seem to reach the clinic. The current review provides an overview of the more recent innovations in liposomal treatment of rheumatoid arthritis, psoriasis, vascular inflammation, and transplantation. Cutting edge developments include the liposomal delivery of gene and RNA therapeutics and the use of hybrid systems where several liposomal bilayer features, or several drugs, are combined in a single formulation. The majority of the articles reviewed here focus on preclinical animal studies where proof-of-principle of an improved efficacy–safety ratio is observed when using liposomal formulations. A few clinical studies are included as well, which brings us to a discussion about the challenges of clinical translation of liposomal nanomedicines in the field of inflammatory diseases.


2021 ◽  
Vol 2 ◽  
Author(s):  
Latifa Koussih ◽  
Samira Atoui ◽  
Omar Tliba ◽  
Abdelilah S. Gounni

Pentraxins are soluble pattern recognition receptors that play a major role in regulating innate immune responses. Through their interaction with complement components, Fcγ receptors, and different microbial moieties, Pentraxins cause an amplification of the inflammatory response. Pentraxin-3 is of particular interest since it was identified as a biomarker for several immune-pathological diseases. In allergic asthma, pentraxin-3 is produced by immune and structural cells and is up-regulated by pro-asthmatic cytokines such as TNFα and IL-1β. Strikingly, some recent experimental evidence demonstrated a protective role of pentraxin-3 in chronic airway inflammatory diseases such as allergic asthma. Indeed, reduced pentraxin-3 levels have been associated with neutrophilic inflammation, Th17 immune response, insensitivity to standard therapeutics and a severe form of the disease. In this review, we will summarize the current knowledge of the role of pentraxin-3 in innate immune response and discuss the protective role of pentraxin-3 in allergic asthma.


2020 ◽  
Author(s):  
Nigeer Te ◽  
Jordi Rodon ◽  
Maria Ballester ◽  
Mónica Pérez ◽  
Lola Pailler-García ◽  
...  

ABSTRACTWhile MERS-CoV (Middle East respiratory syndrome Coronavirus) provokes a lethal disease in humans, camelids, the main virus reservoir, are asymptomatic carriers, suggesting a crucial role for innate immune responses in controlling the infection. Experimentally infected camelids clear infectious virus within one week and mount an effective adaptive immune response. Here, transcription of immune response genes was monitored in the respiratory tract of MERS-CoV infected alpacas. Concomitant to the peak of infection, occurring at 2 days post inoculation (dpi), type I and III interferons (IFNs) were maximally transcribed only in the nasal mucosa of alpacas, provoking the induction of interferon stimulated genes (ISGs) along the whole respiratory tract. Simultaneous to mild focal infiltration of leukocytes in nasal mucosa and submucosa, upregulation of the anti-inflammatory cytokine IL10 and dampened transcription of pro-inflammatory genes under NF-κB control were observed. In the lung, early (1 dpi) transcription of chemokines (CCL2 and CCL3) correlated with a transient accumulation of mainly mononuclear leukocytes. A tight regulation of IFNs in lungs with expression of ISGs and controlled inflammatory responses, might contribute to virus clearance without causing tissue damage. Thus, the nasal mucosa, the main target of MERS-CoV in camelids, is central in driving an efficient innate immune response based on triggering ISGs as well as the dual anti-inflammatory effects of type III IFNs and IL10.IMPORTANCEMiddle East respiratory syndrome coronavirus (MERS-CoV) is the etiological agent of a respiratory disease causing high mortality in humans. In camelids, the main MERS-CoV reservoir host, viral infection leads to subclinical disease. Our study describes transcriptional regulations of innate immunological pathways underlying asymptomatic clinical manifestations of alpacas in response to MERS-CoV. Concomitant to the peak of infection, these animals elicited a strong transient interferon response and induction of the anti-inflammatory cytokine IL10 in the nasal mucosa. This was associated to a dimmed regulation of pro-inflammatory cytokines and induction of interferon stimulated genes along the whole respiratory mucosa, leading to the rapid clearance of the virus. Thus, innate immune responses occurring in the nasal mucosa appear to be the key in controlling MERS-CoV disease by avoiding a cytokine storm. Understanding on how asymptomatic host reservoirs counteract MERS-CoV infection will aid in the development of antiviral drugs and vaccines.


2020 ◽  
Author(s):  
Nigeer Te ◽  
Jordi Rodon ◽  
Maria Ballester ◽  
Mónica Pérez ◽  
Lola Pailler-García ◽  
...  

AbstractWhile MERS-CoV (Middle East respiratory syndrome Coronavirus) provokes a lethal disease in humans, camelids, the main virus reservoir, are asymptomatic carriers, suggesting a crucial role for innate immune responses in controlling the infection. Experimentally infected camelids clear infectious virus within one week and mount an effective adaptive immune response. Here, transcription of immune response genes was monitored in the respiratory tract of MERS-CoV infected alpacas. Concomitant to the peak of infection, occurring at 2 days post inoculation (dpi), type I and III interferons (IFNs) were maximally transcribed only in the nasal mucosa of alpacas, provoking the induction of interferon stimulated genes (ISGs) along the whole respiratory tract. Simultaneous to mild focal infiltration of leukocytes in nasal mucosa and submucosa, upregulation of the anti-inflammatory cytokine IL10 and dampened transcription of pro-inflammatory genes under NF-κB control were observed. In the lung, early (1 dpi) transcription of chemokines (CCL2 and CCL3) correlated with a transient accumulation of mainly mononuclear leukocytes. A tight regulation of IFNs in lungs with expression of ISGs and controlled inflammatory responses, might contribute to virus clearance without causing tissue damage. Thus, the nasal mucosa, the main target of MERS-CoV in camelids, is central in driving an efficient innate immune response based on triggering ISGs as well as the dual anti-inflammatory effects of type III IFNs and IL10.Author summaryMiddle East respiratory syndrome coronavirus (MERS-CoV) is the etiological agent of a respiratory disease causing high mortality in humans. In camelids, the main MERS-CoV reservoir host, viral infection leads to subclinical disease. Our study describes transcriptional regulations of innate immunological pathways underlying asymptomatic clinical manifestations of alpacas in response to MERS-CoV. Concomitant to the peak of infection, these animals elicited a strong transient interferon response and induction of the anti-inflammatory cytokine IL10 in the nasal mucosa. This was associated to a dimmed regulation of pro-inflammatory cytokines and induction of interferon stimulated genes along the whole respiratory mucosa, leading to the rapid clearance of the virus. Thus, innate immune responses occurring in the nasal mucosa appear to be the key in controlling MERS-CoV disease by avoiding a cytokine storm. Understanding on how asymptomatic host reservoirs counteract MERS-CoV infection will aid in the development of antiviral drugs and vaccines.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3274-3274
Author(s):  
Lionel Loubaki ◽  
Renée Bazin

Abstract Abstract 3274 Background: Cells from the monocytic lineage are known to play a central role in the immune defense against pathogens. In the adaptive immune response, they act as antigen presenting cells to trigger T and B cell responses. Monocytic cells also participate in innate immunity following recognition of pathogen-associated molecular patterns (PAMPs) such as bacterial lipopolysaccharides (LPS), which leads to their activation and release of very potent inflammatory mediators. The innate immune response thus needs to be tightly regulated to control not only its onset, but also its termination in order to avoid excessive inflammation. Recent studies have shown that the differentiation and functions of monocytic cells involve small RNA species, named microRNAs (miRNAs). MiRNAs are 21–23 nucleotide long single strand RNAs, which mainly cause gene silencing by degradation of target mRNAs or by inhibition of translation. Among them, miR-146a has captivated interest as it plays an important role in the negative regulation of acute inflammatory responses during activation of the innate immune system. In fact, it has been shown that miR-146a expression is gradually increased in THP-1 monocytic cells following stimulation with LPS or cytokines (e.g. IL-1β and TNF-α) via a NF-κB dependent pathway. MiR-146a inhibits the expression of IRAK1 and TRAF6 leading to the subsequent suppression of NF-κB activity. Consequently, the expression of NF-κB target genes such as IL-1β, TNF-α and PU.1 is suppressed. Therefore, miR146a controls NF-κB signaling via a negative feedback regulation loop and thus can be considered as an anti-inflammatory mediator. IVIg is a therapeutic preparation of polyclonal human IgG isolated from the plasma of thousands of healthy donors. IVIg is well known for its anti-inflammatory effects on a variety of immune cells and processes. More precisely, it has been shown to abrogate the capacity of monocyte-derived dendritic cells to secrete pro-inflammatory cytokines while increasing the expression of anti-inflammatory cytokines such as IL-10. We thus hypothesize that at least some of the anti-inflammatory effects of IVIg on monocytic cells could be triggered through the modulation of miR-146a expression. Objectives: To evaluate the involvement of miR-146a in the anti-inflammatory effects of IVIg following LPS stimulation of human monocytes. Methods: Human monocytes were obtained from the blood of healthy volunteers and treated with LPS (1 mg/mL) or IVIg (15 mg/mL) alone or alternatively, pretreated with LPS followed by addition of IVIg. Pre-treatment with LPS was done during for 4 h prior to addition of IVIg for 3, 6, 12 and 24 hours. Cells were then recovered and separated in two parts. The first part was used to extract the small RNA fraction of total RNA for miRNA analysis and the second part was used for protein isolation. The miR-146a level was measured by real time PCR while NF-kB and IRF4 protein levels were evaluated by western blotting. Finally, the expression of the transcription factor PU.1 was evaluated by flow cytometry. Results: Our preliminary data revealed that addition of IVIg to LPS-pretreated human monocytes resulted in a significant upregulation of miR-146a expression associated with a significant reduction in NF-κB expression. Furthermore, the expression of the PU.1/IRF4 transcriptional activator complex involved in the stimulation of inflammatory cytokine production was modulated. Indeed, we found that the expression PU.1 was reduced in IVIg-treated cells whereas IRF4 expression was increased, thus promoting the IRF4-mediated cytokine production inhibitory pathway. Conclusion: Our preliminary data suggest that in human monocytes, the anti-inflammatory effects of IVIg may involve miR-146a negative feedback loop regulation of NF-κB activity. Disclosures: No relevant conflicts of interest to declare.


2010 ◽  
Vol 1 (3) ◽  
pp. 114-121
Author(s):  
Sim K Singhrao ◽  
St John Crean

The commonality in periodontitis with diverse inflammatory diseases is the silent emergence of pathology within the affected organ suggestive of a continual lowgrade chronic inflammation. The systemic circulation appears to be the conduit that disseminates inflammatory effectors from a given site to distant organs. Although definitive evidence remains tantalisingly out of reach, the inflammatory link between periodontitis and diseases such as atherosclerosis, rheumatoid arthritis and Alzheimer’s disease, involving cellular and humoral components of the innate immune response, is highly plausible.


2005 ◽  
Vol 5 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Annamaria Vezzani

In recent years, increasing evidence has indicated that immune and inflammatory reactions occur in brain in various central nervous system (CNS) diseases. Furthermore, inflammatory processes, such as the production of proinflammatory cytokines and related molecules, have been described in brain after seizures induced in experimental models and in clinical cases of epilepsy. Although little is known about the role of inflammation in epilepsy, it has been hypothesized that activation of the innate immune system and associated inflammatory reactions in brain may mediate some of the molecular and structural changes occurring during and after seizure activity. Whether the innate immune response that takes place in epileptic tissue is beneficial or noxious to the CNS is still an open and intriguing question that should be addressed by further investigations.


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