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Impact of novel N-aryl substituted piperamide on NF-kappa B translocation as a potent anti-neuroinflammatory agent.
Shahbazi, S, Zakerali, T, Frycz, B, Kaur, J
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2020;:110199
Abstract
NF-kB translocation is the key point in the upstream neuroinflammatory pathways. It plays an import role in the pro-inflammatory chemokine, cytokine, and various enzyme expressions, consequently leading to the inflammatory response of the innate immune system. The NF-kB complex consists of structural homolog subunits, including c-Rel, RelB, p52, p65, and p50. Among the p65 subunit has a vital function of NF-kB translocation and DNA binding. NF-kB translocation may occur due to acetylation and phosphorylation LYS 310 and SER311 amino acids in chain A of the p65 subunit in response to IKK-α/β activity. Therefore, there are two ways to inhibit the NF-kB translocation, either directly blocking the active sites of IKK-α/β enzymes or protecting the LYS 310 and SER311 of p65 subunit from acetylation and phosphorylation. NF-kB translocation inhibitors can maintain the NF-kB complex in the inactive form inside the cytosol. In this study, we have designed and developed an NF-kB translocation inhibitor, D4. We have performed various in silico, in vitro and in situ studies on the anti-neuroinflammatory function of D4. It showed the ability to inhibit IKK-α/β in both genome and proteome levels and protect LYS310 of the p65 subunit of NF-kB from the acetylation process. Therefore, we can suggest D4 as the promising anti-neuroinflammatory agent with a function on the upstream process of inflammatory pathways.
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Functional domains of SP110 that modulate its transcriptional regulatory function and cellular translocation.
Leu, JS, Chang, SY, Mu, CY, Chen, ML, Yan, BS
Journal of biomedical science. 2018;(1):34
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Abstract
BACKGROUND SP110, an interferon-induced nuclear protein, belongs to the SP100/SP140 protein family. Very recently, we showed that SP110b, an SP110 isoform, controls host innate immunity to Mycobacterium tuberculosis infection by regulating nuclear factor-κB (NF-κB) activity. However, it remains unclear how the structure of SP110 relates to its cellular functions. In this study, we provide experimental data illustrating the protein domains that are responsible for its functions. METHODS We examined the effects of SP110 isoforms and a series of deletion mutants of SP110 on transcriptional regulation by luciferase reporter assays. We also employed confocal microscopy to determine the cellular distributions of enhanced green fluorescent protein-tagged SP110 isoforms and SP110 mutants. In addition, we performed immunoprecipitation and Western blotting analyses to identify the regions of SP110 that are responsible for protein interactions. RESULTS Using reporter assays, we first demonstrated that SP110 isoforms have different regulatory effects on NF-κB-mediated transcription, supporting the notion that SP110 isoforms may have distinct cellular functions. Analysis of deletion mutants of SP110 showed that the interaction of the N-terminal fragment (amino acids 1-276) of SP110 with p50, a subunit of NF-κB, in the cytoplasm plays a crucial role in the down-regulation of the p50-driven tumor necrosis factor-α (TNFα) promoter activity in the nucleus, while the middle and C-terminal regions of SP110 localize it to various cellular compartments. Surprisingly, a nucleolar localization signal (NoLS) that contains one monopartite nuclear localization signal (NLS) and one bipartite NLS was identified in the middle region of SP110. The identification of a cryptic NoLS in the SP110 suggests that although this protein forms nuclear speckles in the nucleoplasm, it may be directed into the nucleolus to carry out distinct functions under certain cellular conditions. CONCLUSIONS The findings from this study elucidating the multidomain structure of the SP110 not only identify functional domains of SP110 that are required for transcriptional regulation, cellular translocation, and protein interactions but also implicate that SP110 has additional functions through its unexpected activity in the nucleolus.
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The Importance of Toll-like Receptors in NF-κB Signaling Pathway Activation by Helicobacter pylori Infection and the Regulators of this Response.
Hu, Y, Liu, JP, Zhu, Y, Lu, NH
Helicobacter. 2016;(5):428-40
Abstract
Helicobacter pylori (H. pylori) is a common pathogenic bacterium in the stomach that infects almost half of the population worldwide and is closely related to gastric diseases and some extragastric diseases, including iron-deficiency anemia and idiopathic thrombocytopenic purpura. Both the Maastricht IV/Florence consensus report and the Kyoto global consensus report have proposed the eradication of H. pylori to prevent gastric cancer as H.pylori has been shown to be a major cause of gastric carcinogenesis. The interactions between H. pylori and host receptors induce the release of the proinflammatory cytokines by activating proinflammatory signaling pathways such as nuclear factor kappa B (NF-κB), which plays a central role in inflammation, immune response, and carcinogenesis. Among these receptors, Toll-like receptors (TLRs) are classical pattern recognition receptors in the recognition of H. pylori and the mediation of the host inflammatory and immune responses to H. pylori. TLR polymorphisms also contribute to the clinical consequences of H. pylori infection. In this review, we focus on the functions of TLRs in the NF-κB signaling pathway activated by H. pylori, the regulators modulating this response, and the functions of TLR polymorphisms in H.pylori-related diseases.
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Dark chocolate attenuates intracellular pro-inflammatory reactivity to acute psychosocial stress in men: A randomized controlled trial.
Kuebler, U, Arpagaus, A, Meister, RE, von Känel, R, Huber, S, Ehlert, U, Wirtz, PH
Brain, behavior, and immunity. 2016;:200-208
Abstract
Flavanol-rich dark chocolate consumption relates to lower risk of cardiovascular mortality, but underlying mechanisms are elusive. We investigated the effect of acute dark chocolate consumption on inflammatory measures before and after stress. Healthy men, aged 20-50years, were randomly assigned to a single intake of either 50g of flavanol-rich dark chocolate (n=31) or 50g of optically identical flavanol-free placebo-chocolate (n=34). Two hours after chocolate intake, both groups underwent the 15-min Trier Social Stress Test. We measured DNA-binding-activity of the pro-inflammatory transcription factor NF-κB (NF-κB-BA) in peripheral blood mononuclear cells, as well as plasma and whole blood mRNA levels of the pro-inflammatory cytokines IL-1β and IL-6, and the anti-inflammatory cytokine IL-10, prior to chocolate intake as well as before and several times after stress. We also repeatedly measured the flavanol epicatechin and the stress hormones epinephrine and cortisol in plasma and saliva, respectively. Compared to the placebo-chocolate-group, the dark-chocolate-group revealed a marginal increase in IL-10 mRNA prior to stress (p=0.065), and a significantly blunted stress reactivity of NF-κB-BA, IL-1β mRNA, and IL-6 mRNA (p's⩽0.036) with higher epicatechin levels relating to lower pro-inflammatory stress reactivity (p's⩽0.033). Stress hormone changes to stress were controlled. None of the other measures showed a significant chocolate effect (p's⩾0.19). Our findings indicate that acute flavanol-rich dark chocolate exerts anti-inflammatory effects both by increasing mRNA expression of the anti-inflammatory cytokine IL-10 and by attenuating the intracellular pro-inflammatory stress response. This mechanism may add to beneficial effects of dark chocolate on cardiovascular health.
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Regulation of platelet responses triggered by Toll-like receptor 2 and 4 ligands is another non-genomic role of nuclear factor-kappaB.
Rivadeneyra, L, Carestia, A, Etulain, J, Pozner, RG, Fondevila, C, Negrotto, S, Schattner, M
Thrombosis research. 2014;(2):235-43
Abstract
INTRODUCTION Platelets express Toll-like receptors (TLRs) that recognise molecular components of pathogens and, in nucleated cells, elicit immune responses through nuclear factor-kappaB (NF-κB) activation. We have shown that NF-κB mediates platelet activation in response to classical agonists, suggesting that this transcription factor exerts non-genomic functions in platelets. The aim of this study was to determine whether NF-κB activation is a downstream signal involved in TLR2 and 4-mediated platelet responses. MATERIAL AND METHODS Aggregation and ATP release were measured with a Lumi-aggregometer. Fibrinogen binding, P-selectin and CD40 ligand (CD40L) levels and platelet-neutrophil aggregates were measured by cytometry. I kappa B alpha (IκBα) degradation and p65 phosphorylation were determined by Western blot and von Willebrand factor (vWF) by ELISA. RESULTS Platelet stimulation with Pam3CSK4 or LPS resulted in IκBα degradation and p65 phosphorylation. These responses were suppressed by TLR2 and 4 blocking and synergised by thrombin. Aggregation, fibrinogen binding and ATP and vWF release were triggered by Pam3CSK4. LPS did not induce platelet responses per se, except for vWF release, but it did potentiate thrombin-induced aggregation, fibrinogen binding and ATP secretion. Pam3CSK4, but not LPS, induced P-selectin and CD40L expression and mixed aggregate formation. All of these responses, except for CD40L expression, were inhibited in platelets treated with the NF-κB inhibitors BAY 11-7082 or Ro 106-9920. CONCLUSION TLR2 and 4 agonists trigger platelet activation responses through NF-κB. These data show another non-genomic function of NF-κB in platelets and highlight this molecule as a potential target to prevent platelet activation in inflammatory or infectious diseases.
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MicroRNA-146 inhibits thrombin-induced NF-κB activation and subsequent inflammatory responses in human retinal endothelial cells.
Cowan, C, Muraleedharan, CK, O'Donnell, JJ, Singh, PK, Lum, H, Kumar, A, Xu, S
Investigative ophthalmology & visual science. 2014;(8):4944-51
Abstract
PURPOSE Nuclear factor-κB (NF-κB), a key regulator of immune and inflammatory responses, plays important roles in diabetes-induced microvascular complications including diabetic retinopathy (DR). Thrombin activates NF-κB through protease-activated receptor (PAR)-1, a member of the G-protein-coupled receptor (GPCR) superfamily, and contributes to DR. The current study is to uncover the roles of microRNA (miRNA) in thrombin-induced NF-κB activation and retinal endothelial functions. METHODS Target prediction was performed using the TargetScan algorithm. Predicted target was experimentally validated by luciferase reporter assays. Human retinal endothelial cells (HRECs) were transfected with miRNA mimics or antimiRs and treated with thrombin. Expression levels of miR-146 and related protein-coding genes were analyzed by quantitative (q)RT-PCR. Functional changes of HRECs were analyzed by leukocyte adhesion assays. RESULTS We identified that caspase-recruitment domain (CARD)-containing protein 10 (CARD10), an essential scaffold/adaptor protein of GPCR-mediated NF-κB activation pathway, is a direct target of miR-146. Thrombin treatment resulted in NF-κB-dependent upregulation of miR-146 in HRECs; while transfection of miR-146 mimics resulted in significant downregulation of CARD10 and prevented thrombin-induced NF-κB activation, suggest that a negative feedback regulation of miR-146 on thrombin-induced NF-κB through targeting CARD10. Furthermore, overexpression of miR-146 prevented thrombin-induced increased leukocyte adhesion to HRECs. CONCLUSIONS We uncovered a novel negative feedback regulatory mechanism on thrombin-induced GPCR-mediated NF-κB activation by miR-146. In combination with the negative feedback regulation of miR-146 on the IL-1R/toll-like receptor (TLR)-mediated NF-κB activation in RECs that we reported previously, our results underscore a pivotal, negative regulatory role of miR-146 on multiple NF-κB activation pathways and related inflammatory processes in DR.
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Effects of 20-hydroxyecdysone, Leuzea carthamoides extracts, dexamethasone and their combinations on the NF-κB activation in HeLa cells.
Peschel, W, Kump, A, Prieto, JM
The Journal of pharmacy and pharmacology. 2011;(11):1483-95
Abstract
OBJECTIVES The plant steroid 20-hydroxyecdysterone (20E) and 20E-containing extracts from Leuzea carthamoides (Willd.) DC are sold with claims of anabolic and immunomodulatory effects. Yet their effect on the activation of nuclear factor kappa B (NF-κB), a key player in immune response and cell fate, and their influence on the NF-κB-inhibiting activity of steroidal anti-inflammatory drugs is still unknown. METHODS The ability of 20E, Leuzea extracts and selected steroidal/non-steroidal anti-inflammatory drugs to influence the activation of NF-κB was explored using, as the experimental model, human cervical cancer HeLa-IL-6 cells stably transfected with an IL-6-bound reporter gene. Effects on cell viability and proliferation were monitored (MTT assay). HPLC-DAD was used to establish links between chemical patterns of Leuzea extracts and their bioactivities. KEY FINDINGS 20E inhibited NF-κB activation (IC50 31.8 µm) but was less active than other plant metabolites (xanthohumol 3.8 µm, withaferin A 1.4 µm). Leuzea extracts with high content in 20E had a fair activating effect, but in contrast, some extracts with low 20E content significantly inhibited NF-κB activation at IC50s ranging from 3.5 to 6.2 µg/ml. Combination tests confirmed that 20E does not explain the NF-κB modulation achieved by Leuzea extracts. The extracts but not 20E itself showed a significant modulation of the NF-κB inhibitory effect of dexamethasone. CONCLUSIONS 20E is unlikely a major player in the NF-κB inhibitory effects displayed by some Leuzea extracts in vitro. If confirmed in vivo, caution should prevail towards marketed Leuzea extracts that are non-standardised or standardised on 20E only, since different starting materials and extracts may even cause opposite effects. More importantly, our results indicate the interaction potential of Leuzea with steroidal anti-inflammatory drugs.
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[Encounter of cancer cells with bone. Cancer and inflammation--input and output of NF-κB - ].
Maru, Y
Clinical calcium. 2011;(3):364-71
Abstract
NF-κB activation is frequently found in a variety of tumors, especially in those that are resistant to chemotherapy. The malignant phenotypes of tumor cells that are required for invasion and metastasis could be established by the output of NF-κB signaling including interactions with white blood cells, anti-apoptosis and angiogenesis. Consequently, by utilizing the similar mechanisms for immune cells to migrate through the body, tumor cells migrate via blood stream, survive against selective pressures in other organs they stop by, achieve re-growth as metastasis, or make a clinical relapse by traveling back to the primary site.
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β-Carotene and lutein inhibit hydrogen peroxide-induced activation of NF-κB and IL-8 expression in gastric epithelial AGS cells.
Kim, Y, Seo, JH, Kim, H
Journal of nutritional science and vitaminology. 2011;(3):216-23
Abstract
Reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)) are involved in the pathogenesis of gastric inflammation. Interleukin-8 (IL-8) is a potent mediator of the inflammatory response by activating and recruiting neutrophils to the site of infection. Oxidant-sensitive transcription factor NF-κB regulates the expression of IL-8 in the immune and inflammatory events. Carotenoids (carotenes and oxygenated carotenoids) show antioxidant and anti-inflammatory activities. Low intake of β-carotene leads to high risk of gastric cancer. Oxygenated carotenoid lutein inhibited NF-κB activation in experimental uveitis. The present study aims to investigate whether β-carotene and lutein inhibit H(2)O(2)-induced activation of NF-κB and expression of IL-8 in gastric epithelial AGS cells. The cells were treated with carotenoids 2 h prior to the treatment of H(2)O(2). mRNA expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and real time RT-PCR analyses. IL-8 level in the medium was determined by enzyme-linked immunosorbent assay. NF-κB activation was assessed by electrophoretic mobility shift assay. ROS levels of the cells were detected by confocal microscopic analysis for fluorescent dichlorofluorescein. As a result, H(2)O(2 )induced the activation of NF-κB and expression of IL-8 in AGS cells time-dependently. β-Carotene and lutein showed inhibitory effects on H(2)O(2)-induced increase in intracellular ROS levels, activation of NF-κB, and IL-8 expression in AGS cells. In conclusion, supplementation of carotenoids such as β-carotene and lutein may be beneficial for the treatment of oxidative stress-mediated gastric inflammation.
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The role of chalcones in suppression of NF-κB-mediated inflammation and cancer.
Yadav, VR, Prasad, S, Sung, B, Aggarwal, BB
International immunopharmacology. 2011;(3):295-309
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Abstract
Although consumption of fruits, vegetables, spices, cereals and pulses has been associated with lower incidence of cancer and other chronic diseases, how these dietary agents and their active ingredients minimize these diseases, is not fully understood. Whether it is oranges, kawa, hops, water-lilly, locorice, wax apple or mulberry, they are all connected by a group of aromatic ketones, called chalcones (1,3-diaryl-2-propen-1-ones). Some of the most significant chalcones identified from these plants include flavokawin, butein, xanthoangelol, 4-hydroxyderricin, cardamonin, 2',4'-dihydroxychalcone, isoliquiritigenin, isosalipurposide, and naringenin chalcone. These chalcones have been linked with immunomodulation, antibacterial, antifungal, antiviral, anti-inflammatory, antioxidant, anticancer, and antidiabetic activities. The current review, however, deals with the role of various chalcones in inflammation that controls both the immune system and tumorigenesis. Inflammatory pathways have been shown to mediate the survival, proliferation, invasion, angiogenesis and metastasis of tumors. How these chalcones modulate inflammatory pathways, tumorigenesis and immune system is the focus of this review.