NF-kappaB family of transcription factors: central regulators of innate and adaptive immune functions

Resveratrol decreases the expression of genes involved in inflammation through transcriptional regulation

Oxidative stress generated during inflammation is associated with a wide range of pathologies. Resveratrol (RESV) displays anti-inflammatory and antioxidant activities, being a candidate for the development of adjuvant therapies for several inflammatory diseases. Despite this potential, the cellular responses induced by RESV are not well known. In this work, transcriptomic analysis was performed following lipopolysaccharide (LPS) stimulation of monocyte cultures in the presence of RESV. Induction of an inflammatory response was observed after LPS treatment and the addition of RESV led to decreases in expression of the inflammatory mediators, tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1), without cytotoxicity. RNA sequencing revealed 823 upregulated and 2098 downregulated genes (cutoff ≥2.0 or ≤-2.0) after RESV treatment. Gene ontology analysis showed that the upregulated genes were associated with metabolic processes and the cell cycle, consistent with normal cell growth and differentiation under an inflammatory stimulus. The downregulated genes were associated with inflammatory responses, gene expression, and protein modification. The prediction of master regulators using the iRegulon tool showed nuclear respiratory factor 1 (NRF1) and GA-binding protein alpha subunit (GABPA) as the main regulators of the downregulated genes. Using immunoprecipitation and protein expression assays, we observed that RESV was able to decrease protein acetylation patterns, such as acetylated apurinic/apyrimidinic endonuclease-1/reduction-oxidation factor 1 (APE1/Ref-1), and increase histone methylation. In addition, reductions in p65 (nuclear factor-kappa B (NF-κB) subunit) and lysine-specific histone demethylase-1 (LSD1) expression were observed. In conclusion, our data indicate that treatment with RESV caused significant changes in protein acetylation and methylation patterns, suggesting the induction of deacetylase and reduction of demethylase activities that mainly affect regulatory cascades mediated by NF-кB and Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling. NRF1 and GABPA seem to be the main regulators of the transcriptional profile observed after RESV treatment.

An ultrasensitive electrochemiluminescence biosensor for nuclear factor kappa B p50 based on the proximity hybridization-induced hybridization chain reaction

Nuclear factor kappa B p50 (NF-κB p50) induces various biological processes.

Pilloin, A Flavonoid Isolated from Aquilaria sinensis, Exhibits Anti-Inflammatory Activity In Vitro and In Vivo

Flavonoids, widely present in medicinal plants and fruits, are known to exhibit multiple pharmacological activities. In this study, we isolated a flavonoid compound, pilloin, from Aquilaria sinensis and investigated its anti-inflammatory activity in bacterial lipopolysaccharide-induced RAW 264.7 macrophages and septic mice. Pilloin inhibited NF-κB activation and reduced the phosphorylation of IκB in LPS-stimulated macrophages. Moreover, pilloin significantly suppressed the production of pro-inflammatory molecules, such as TNF-α, IL-6, COX-2 and iNOS, in LPS-treated RAW 264.7 macrophages. Additionally, pilloin suppressed LPS-induced morphological alterations, phagocytic activity and ROS elevation in RAW 264.7 macrophages. The mitogen-activated protein kinase-mediated signalling pathways (including JNK, ERK, p38) were also inhibited by pilloin. Furthermore, pilloin reduced serum levels of TNF-α (from 123.3 ± 7 to 46.6 ± 5.4 ng/mL) and IL-6 levels (from 1.4 ± 0.1 to 0.7 ± 0.1 ng/mL) in multiple organs of LPS-induced septic mice (liver: from 71.8 ± 3.2 to 36.7 ± 4.3; lung: from 118.6 ± 10.6 to 75.8 ± 11.9; spleen: from 185.9 ± 23.4 to 109.6 ± 18.4; kidney: from 160.3 ± 11.8 to 75 ± 10.8 pg/mL). In summary, our results demonstrate the anti-inflammatory potential of pilloin and reveal its underlying molecular mechanism of action.

CNBP controls IL-12 gene transcription and Th1 immunity

These studies reveal a previously unrecognized role for Cnbp as a novel transcriptional regulator engaged downstream of innate immune receptors controlling the c-Rel–IL-12–Th1 axis, which has important implications for both host defense and inflammatory disease.

An inducible program of inflammatory gene expression is a hallmark of antimicrobial defenses. Recently, cellular nucleic acid–binding protein (CNBP) was identified as a regulator of nuclear factor-kappaB (NF-κB)–dependent proinflammatory cytokine gene expression. Here, we generated mice lacking CNBP and found that CNBP regulates a very restricted gene signature that includes IL-12β. CNBP resides in the cytosol of macrophages and translocates to the nucleus in response to diverse microbial pathogens and pathogen-derived products. Cnbp-deficient macrophages induced canonical NF-κB/Rel signaling normally but were impaired in their ability to control the activation of c-Rel, a key driver of IL-12β gene transcription. The nuclear translocation and DNA-binding activity of c-Rel required CNBP. Lastly, Cnbp-deficient mice were more susceptible to acute toxoplasmosis associated with reduced production of IL-12β, as well as a reduced T helper type 1 (Th1) cell IFN-γ response essential to controlling parasite replication. Collectively, these findings identify CNBP as important regulator of c-Rel–dependent IL-12β gene transcription and Th1 immunity.

A Novel Small Peptide Inhibitor of NFκB, RH10, Blocks Oxidative Stress-Dependent Phenotypes in Cancer

Background

The RH domain of GRK5 is an effective modulator of cancer growth through the inhibition of NFκB activity. The aim of this study was to identify the minimum effective sequence of RH that is still able to inhibit tumor growth and could be used as a peptide-based drug for therapy.

Methods

Starting from the RH sequence, small peptides were cloned and tested in KAT-4 cells. The effects on NFκB signaling and its dependent phenotypes were evaluated by Western blot, TUNEL assay, proliferation assay, and angiogenesis in vitro. In vivo experiments were performed in KAT-4 xenografts in Balb/c nude mice.

Results

A minimum RH ten amino acids long sequence (RH10) was able to interact with IκB, to increase IκB levels, to induce apoptosis, to inhibit KAT4-cell proliferation, NFκB activation, ROS production, and angiogenesis in vitro. In vivo, the peptide inhibited tumor growth in a dose-dependent manner. We also tested its effects in combination with chemotherapeutic drugs and radiotherapy. RH10 ameliorated the antitumor responses to cisplatin, doxorubicin, and ionizing radiation.

Conclusion

Our data propose RH10 as a potential peptide-based drug to use for cancer treatment both alone or in combination with anticancer therapies.

Hydrogen-rich water ameliorates rat placental stress induced by water restriction

Dehydration is one of the intrauterine abnormalities that could lead to fetal growth retardation and to increase the risk of a variety of adult diseases later in life. This study were to determine the impact of hydrogen-rich water (HRW) supplementation on placental angiotensin II type 1 receptor and placental oxidative stress induced by water restriction. Pregnant Wistar rat were randomly assigned to one of the three groups (n =12 per group). In control group, pure water and food were supplied ad libitum. Water restriction group and HRW group were respectively given pure water and HRW with free access to food, excepting only one hour was available for drinking from day 7 to day 17 of pregnancy. The placental damages and biomarkers of stress were detected by histopathology, immunohistochemistry and western blot, as well as serological test were performed. We demonstrated that maternal water restriction resulted in reduced urine volume and increased serum osmotic pressure, along with decreased fetus weight and crown-rump length. Although placental weight and the number of fetuses had no significant difference among groups, the placental efficiency significantly increased after the oral administration of HRW to the mothers. Meanwhile, the serological derivatives of reactive oxygen metabolites decreased, a significant improvement of placental microstructure with more developed junctional zone and denser labyrinth was manifested, the upregulated expression of angiotensin II type 1 receptor, nuclear factoκB, malondialdehyde, 8-hydroxydeoxyguanosine, p38, c-Jun N-terminal kinase and down-regulation of superoxide dismutase were revealed in the placenta. Collectively, HRW administration is able to effectively attenuate placental stress induced by water restriction.

The Adverse Effects of Se Toxicity on Inflammatory and Immune Responses in Chicken Spleens

Selenium (Se) is an essential trace element, but excessive intake of Se could induce Se poisoning, and result in various health problems. NF-κB regulated many molecules of the immune response and the inflammatory response, and Th1/Th2 balance played a key in the regulation of immune response. The aim of this study is to investigate the role of NF-κB pathway and Th1/Th2 imbalance in the adverse influence of Se poisoning on chicken spleens. In the current study, 90 chickens were randomly divided into two groups (n = 45 per group). The chickens were maintained either on a basal diet (the control group) containing 0.2 mg/kg Se or a high supplemented diet (the Se group) containing 15 mg/kg Se for 45 days. Then, we observed the pathohistology of spleen cells and detected NO content, iNOS activity, and the expression of NF-κB, iNOS, COX-2, PTGE, IL-6, TNF-α, Foxp3, IL-4, and IFN-γ in chicken spleens. In chicken spleens of the Se group, the result showed typical characteristics of inflammation: the content of NO and the activity of iNOS were increased, and the expression of NF-κB, iNOS, COX-2, PTGE, IL-6, TNF-α, and IL-4 was enhanced and that of Foxp3 and IFN-γ was decreased. Our study showed that Se toxicity could promote inflammation via NF-κB pathway, impairing the immune function, and changing Th1/Th2 balance in the chicken spleens.

Activation of NF-κB induced by TRIMCyp showing a discrepancy between owl monkey and northern pig-tailed macaque

TRIMCyp generated by retrotransposition of a cyclophilin A inserting into TRIM5 locus, has been identified in owl monkey and most of Old World monkeys (OWM). Owl monkey TRIMCyp (omTRIMCyp) inhibits HIV-1 infection by direct interaction with viral capsid and indirect innate immune induction, whereas most of TRIMCyps from OWM cannot inhibit HIV-1, and the impact of which on immunoregulation is largely unknown. Here we reported that omTRIMCyp induces NF-κB, AP-1 and IFN-β activation in a dose-dependent manner, while TRIMCyp from northern pig-tailed macaque (npmTRIMCyp) does not activate NF-κB and moderately enhances AP-1 and IFN-β activities. The Cyclophilin A (CypA) domain plays an important role in omTRIMCyp-mediated NF-κB activation, and RBCC domains have a synergetic effect. We further indicated the mechanism by which npmTRIMCyp unable to activate NF-κB is that npmTRIMCyp hardly phosphorylates IκBα, different from omTRIMCyp which dramatically induces IκBα phosphorylation. Ubiquitination activity of omTRIMCyp was greater than npmTRIMCyp, although both could be ubiquitylated. Given that npmTRIMCyp neither interacts with viral capsid resulting in susceptibility to HIV-1 infection, nor activates NF-κB that is indispensable to HIV-1 provirus transcription, we proposed a model that npmTRIMCyp may play an important role in HIV-1 infected northern pig-tailed macaque with latency.

Repurposing Thioridazine (TDZ) as an anti-inflammatory agent

Nuclear factor-kB (NF-kB) is a crucial transcription factor in the signal transduction cascade of the inflammatory signaling. Activation of NF-κB depends on the phosphorylation of IκBα by IκB kinase (IKKβ) followed by subsequent ubiquitination and degradation. This leads to the nuclear translocation of the p50- p65 subunits of NF-κB, and further triggers pro-inflammatory cytokine gene expression. Thus, in the need of a more effective therapy for the treatment of inflammatory diseases, specific inhibition of IKKβ represents a rational alternative strategy to the current therapies. A computer-aided drug identification protocol was followed to identify novel IKKβ inhibitors from a database of over 1500 Food and Drug Administration (FDA) drugs. The best scoring compounds were compared with the already known high-potency IKKβ inhibitors for their ability to bind and inhibit IKKβ by evaluating their docking energy. Finally, Thioridazinehydrochloride (TDZ), a potent antipsychotic drug against Schizophrenia was selected and its efficiency in inhibiting IκBα protein degradation and NF-κB activation was experimentally validated. Our study has demonstrated that TDZ blocks IκBα protein degradation and subsequent NF-κB activation to inhibit inflammation. Thus, it is a potential repurposed drug against inflammation.

RIPK2: New Elements in Modulating Inflammatory Breast Cancer Pathogenesis

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer that is associated with significantly high mortality. In spite of advances in IBC diagnoses, the prognosis is still poor compared to non-IBC. Due to the aggressive nature of the disease, we hypothesize that elevated levels of inflammatory mediators may drive tumorigenesis and metastasis in IBC patients. Utilizing IBC cell models and patient tumor samples, we can detect elevated NF-κB activity and hyperactivation of non-canonical drivers of NF-κB (nuclear factor kappaB)-directed inflammation such as tyrosine phosphorylated receptor-interacting protein kinase 2 (pY RIPK2), when compared to non-IBC cells or patients. Interestingly, elevated RIPK2 activity levels were present in a majority of pre-chemotherapy samples from IBC patients at the time of diagnosis to suggest that patients at diagnosis had molecular activation of NF-κB via RIPK2, a phenomenon we define as “molecular inflammation”. Surprisingly, chemotherapy did cause a significant increase in RIPK2 activity and thus molecular inflammation suggesting that chemotherapy does not resolve the molecular activation of NF-κB via RIPK2. This would impact on the metastatic potential of IBC cells. Indeed, we can demonstrate that RIPK2 activity correlated with advanced tumor, metastasis, and group stage as well as body mass index (BMI) to indicate that RIPK2 might be a useful prognostic marker for IBC and advanced stage breast cancer.

Extracts of Porphyra tenera (Nori Seaweed) Activate the Immune Response in Mouse RAW264.7 Macrophages via NF-κB Signaling

Porphyra tenera, also known as nori, is a red algal species of seaweed. It is cultivated in Asia for culinary purposes. We report that P. tenera extract (PTE) enhances the immune response in mouse macrophages. We found that P. tenera extract regulates the NF-κB IκB kinase (IKK) signaling pathway, and we assessed the expression and translocation of p65, a subunit of NF-κB, in RAW264.7 mouse macrophage cells after treatment with PTE. We also investigated the effects of 10% ethanol PTE (PTE10) in RAW264.7 cells. The production of IL-10, IL-6, TNF-α, and IFN-γ was induced by PTE treatment of the macrophages, and PTE also enhanced p-IκB and p-AKT. PTE10 showed no cytotoxicity at 10-20 μg/mL in RAW264.7 cells. PTE10, in fact, increased cell viability at 24 h, stimulated macrophage cells, and induced the phosphorylation of Akt. Akt stimulates IKK activity through the phosphorylation of IKKα and enhances immune activity through the activation of NF-κB. In this study, NF-κB activation was induced by increasing p-NF-κB and p-IKK. A subunit of NF-κB, p65, was located in the nucleus and increased the expression of various cytokines. PTE thus enhanced the immune response through IκB-α immunostimulation signaling in RAW264.7 cells. PTE10 has potential therefore for development of future treatments requiring immune system stimulation.

Metformin Induces Apoptosis and Alters Cellular Responses to Oxidative Stress in Ht29 Colon Cancer Cells: Preliminary Findings

Accumulating evidence suggests that metformin, used as an antidiabetic drug, possesses anti-cancer properties. Metformin reduced the incidence and growth of experimental tumors in vivo. In a randomized clinical trial among nondiabetic patients, metformin treatment significantly decreased the number of aberrant crypt foci compared to the untreated group with a follow-up of 1 month. In our study, HT29 cells were treated with graded concentrations of metformin, 10 mM/25 mM/50 mM for 24/48 h. We performed immunofluorescence experiments by means of confocal microscopy and western blot analysis to evaluate a panel of factors involved in apoptotic/autophagic processes and oxidative stress response. Moreover, HT29 cells treated with metformin were analyzed by a flow cytometry assay to detect the cell apoptotic rate. The results demonstrate that metformin exerts growth inhibitory effects on cultured HT29 cells by increasing both apoptosis and autophagy; moreover, it affects the survival of cultured cells inhibiting the transcriptional activation of Nuclear factor E2-related factor 2 (NRF-2) and nuclear factor-kappa B (NF-κB). The effects of metformin on HT29 cells were dose- and time-dependent. These results are very intriguing since metformin is emerging as a multi-faceted drug: It has a good safety profile and is associated with low cost and might be a promising candidate for the prevention or the treatment of colorectal cancer.

DARPP-32 and t-DARPP promote non-small cell lung cancer growth through regulation of IKKα-dependent cell migration

Lung cancer is the leading cause of cancer-related death worldwide. Here we demonstrate that elevated expression of dopamine and cyclic adenosine monophosphate-regulated phosphoprotein, Mr 32000 (DARPP-32) and its truncated splice variant t-DARPP promote lung tumor growth, while abrogation of DARPP-32 expression in human non-small cell lung cancer (NSCLC) cells reduces tumor growth in orthotopic mouse models. We observe a novel physical interaction between DARPP-32 and inhibitory kappa B kinase-α (IKKα) that promotes NSCLC cell migration through non-canonical nuclear factor kappa-light-chain-enhancer of activated B cells 2 (NF-κB2) signaling. Bioinformatics analysis of 513 lung adenocarcinoma patients reveals elevated t-DARPP isoform expression is associated with poor overall survival. Histopathological investigation of 62 human lung adenocarcinoma tissues also shows that t-DARPP expression is elevated with increasing tumor (T) stage. Our data suggest that DARPP-32 isoforms serve as a negative prognostic marker associated with increasing stages of NSCLC and may represent a novel therapeutic target.

A functional haplotype of NFKB1 influence susceptibility to oral cancer: a population-based and in vitro study

Genetic variations of NF‐κB and its inhibitor IκB genes and their biological mechanism in oral cancer were not well recognized. The purpose of this study was to evaluate the associations of polymorphisms in NFKB1 and NFKBIA with oral cancer susceptibility, and further explore their potential mechanism in vitro. First, the polymorphisms of NFKB1 and NFKBIA were genotyped through iPLEX Sequenom MassARRAY platform in a case–control study with 425 oral cancer patients and 485 healthy controls. Then, the function was explored by a luciferase reporter assay and an electrophoretic mobility shift assay (EMSA) in human tongue squamous cell carcinoma cell lines. The results indicated that NFKB1 rs28362491 Del/Del and rs72696119 G/G genotypes were associated with the risk of oral cancer, with a strong linkage disequilibrium (D′ = 0.991, r² = 0.971). Moreover, DG haplotype of NFKB1 also showed a significant increased risk (OR = 1.25, 95% CI: 1.02–1.53, P = 0.030). Dual‐luciferase reporter assays further revealed that the plasmids with DG or IG or DC haplotype transfected with Tca‐8113 cells or CAL‐27 cells had a lower luciferase expression than that with IC haplotype. EMSA demonstrated that 4‐bp ATTG deletion in the promoter of NFKB1 abolished the binding site of transcription factor. Our preliminary findings suggest that the haplotype of rs28362491 and rs72696119 in NFKB1 could act as a novel genetic marker to predict oral cancer risk in the southeast of China, but much more extensive researches still need to be conducted.

Dysregulation of CD44v6 may lead to recurrent spontaneous abortion by inhibiting the proliferation and migration of trophoblast cells

In the establishment and continuation of a successful pregnancy, the proliferation, migration, and invasion of trophoblast cells play essential roles. Impaired trophoblast function has been reported to be involved in recurrent spontaneous abortion (RSA) but the potential mechanisms are still unknown. CD44 variant domain 6 (CD44v6) is a transmembrane glycoprotein that has been known for decades to be expressed in the placenta. In this study, we investigated the effect of CD44v6 on proliferation and migration of trophoblast cells. Our results show that CD44v6 expression in the villi is lower in RSA patients than in women with normal pregnancies. Furthermore, downregulation of CD44v6 leads to a reduction in proliferation and migration in the human trophoblast cell line HTR-8/SVneo, along with decreased expression and nuclear translocation of NF-κB. These results suggest that decreased expression of CD44v6 may cause miscarriage by downregulating trophoblast cell proliferation via the NF-κB pathway.

Obesity, Inflammation, Toll-Like Receptor 4 and Fatty Acids

Obesity leads to an inflammatory condition that is directly involved in the etiology of cardiovascular diseases, type 2 diabetes mellitus, and certain types of cancer. The classic inflammatory response is an acute reaction to infections or to tissue injuries, and it tends to move towards resolution and homeostasis. However, the inflammatory process that was observed in individuals affected by obesity and metabolic syndrome differs from the classical inflammatory response in certain respects. This inflammatory process manifests itself systemically and it is characterized by a chronic low-intensity reaction. The toll-like receptor 4 (TLR4) signaling pathway is acknowledged as one of the main triggers of the obesity-induced inflammatory response. The aim of the present review is to describe the role that is played by the TLR4 signaling pathway in the inflammatory response and its modulation by saturated and omega-3 polyunsaturated fatty acids. Studies indicate that saturated fatty acids can induce inflammation by activating the TLR4 signaling pathway. Conversely, omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid and docosahexaenoic acid, exert anti-inflammatory actions through the attenuation of the activation of the TLR4 signaling pathway by either lipopolysaccharides or saturated fatty acids.

Frontline Science: IL-18 primes murine NK cells for proliferation by promoting protein synthesis, survival, and autophagy

Combined stimulation by IL-2 and IL-18 effectively promotes proliferation of NK cells, whereas singular stimulation does not. In this study, synergistic effects of these cytokines on NK cells proliferation was analyzed, focusing on the roles of IL-18. In splenic resting NK cells from IL-18KO mice, IL-18 rapidly activated NF-κB independently of IL-2, and activated or up-regulated various molecules downstream of PI3K/AKT and mTOR, including S6, Bcl-XL, ATG5, and LC3II, accompanying increases in cell growth and survival. Thus, IL-18 alone was revealed to augment various cellular processes (gene transcription, protein synthesis, survival) in the absence or presence of IL-2. Notably, combined IL-18 and IL-2 promoted autophagosome formation. In addition, priming NK cells with IL-18 augmented IL-2R, especially CD25, and enabled cells to respond to IL-2, resulting in activation of STAT3 and STAT5, followed by increase of cyclin B1 leading to proliferation. However, IL-2 alone failed to activate STAT3 or STAT5 in resting IL18KO NK cells. These results clarify the distinct roles of IL-2 and IL-18 in NK cell proliferation, and the intrinsic roles of IL-18 in various cellular processes, suggesting a range of functions of IL-18 expressed in an array of nonhematopoietic cells.

TET-2 up-regulation is associated with the anti-inflammatory action of Vicenin-2

Vicenin-2, a C-glycoside flavone that is present in many plant sources, exerts potent anti-inflammatory effects in a number of cell and animal models of inflammation. Ten-eleven translocation (TET)-2 has recently gained considerable attention due to the role it plays in regulating the inflammasome. We studied the ability of Vicenin-2 (V-2) to regulate a range of lipopolysaccharide (LPS) stimulated inflammatory activities in PMA-differentiated THP-1 cells and human primary mononuclear cells. We also investigated the action of V-2 on the secretion of NLRP3 inflammasome regulated cytokines (IL-1β and IL-18) by ELISA, and determined if V-2 can regulate the expression of NLRP3, IL-10, IL-1Ra and TET-2. The effect of V-2 on NF-κB signalling was investigated by fluorescence microscopy and gene reporter assay. Additionally, the effect of V-2 on LPS-induced phosphorylation of IKB-α was also investigated by Western blot analysis. V-2 down-regulated LPS-induced secretion of proinflammatory cytokines (TNF-α and IL-1β), in both THP-1 and primary mononuclear cells. V-2 also decreased the LPS-stimulated secretion of IL-18 in THP-1 cells. V-2 significantly down-regulated TNF-α induced NF-κB reporter activity in HEK293T transfected cells and attenuated IKB-α phosphorylation in THP-1 cells. V-2 treatment also induced enhanced nuclear staining of the p50 subunit and reduced p65 subunit of NF-κB. V-2 treatment alone increased the expression of anti-inflammatory cytokine, IL-10, and the regulator of the inflammasome; IL-1Ra, in the presence of LPS. V-2 also significantly decreased LPS-induced NLRP3 expression while concomitantly increasing TET-2 expression. This study demonstrates that the anti-inflammatory actions of V-2 are associated not only with increased IL-10 and IL-1Ra expression, but also with TET-2 up-regulation. Further work is required to establish if the effects of V-2 can be definitively linked to TET-2 activity and that these actions are mirrored in a range of relevant cell types.

(DEAD)-box RNA helicase 3 modulates NF-κB signal pathway by controlling the phosphorylation of PP2A-C subunit

Asp-Glu-Ala-Asp (DEAD)-box RNA helicase 3 (DDX3), an ATP-dependent RNA helicase, is associated with RNA splicing, mRNA export, transcription, translation, and RNA decay. Recent studies revealed that DDX3 participates in innate immune response during virus infection by interacting with TBK1 and regulating the production of IFN-β. In our studies, we demonstrated that DDX3 regulated NF-κB signal pathway. We found that DDX3 knockdown reduced the phosphorylation of p65 and IKK-β and ultimately attenuated the production of inflammatory cytokines induced by poly(I:C) or TNF-α stimulation. The regulatory effect of DDX3 on NF-κB signal pathway was not affected by the loss of its ATPase or helicase activity. We further identified PP2A C subunit (PP2A-C) as an interaction partner of DDX3 by co-immunoprecipitation and mass spectrum analysis. We confirmed that DDX3 formed the complex with PP2A-C/IKK-β and regulated the interaction between IKK-β and PP2A-C. Furthermore, we demonstrated that DDX3 modulated the activity of PP2A by controlling the phosphorylation of PP2A-C, which might enable PP2A-C to regulate NF-κB signal pathway by dephosphorylating IKK-β. All these findings suggested DDX3 plays multiple roles in modulating innate immune system.

TLR2/MyD88/NF-κB signaling pathway regulates IL-1β production in DF-1 cells exposed to Mycoplasma gallisepticum LAMPs

Mycoplasma gallisepticum (M. gallisepticum) is one of the most important pathogens that cause chronic respiratory disease in chickens. M. gallisepticum-derived lipid-associated membrane proteins (LAMPs) are thought to be one of the major factors in mycoplasma pathogenesis and are potent inducers of the host innate immune response. However, the interaction of pathogenic M. gallisepticum-derived LAMPs with Toll-like receptors (TLRs) and the signaling pathways responsible for activating inflammation and NF-κB have not been fully elucidated. In this study, we found that IL-1β expression was induced in DF-1 cells stimulated with M. gallisepticum LAMPs. Subcellular localization experiments using immunofluorescence assays (IFAs) showed p65 translocation from the cytoplasm to the nucleus in DF-1 cells following stimulation with M. gallisepticum LAMPs. Phosphorylation of p65 was detected in LAMP-stimulated DF-1 cells. Treatment with an NF-κB-specific inhibitor showed that NF-κB is required for M. gallisepticum LAMP-induced IL-1β expression. In addition, the results indicated that TLR2 and myeloid differentiation primary-response protein 88 (MyD88)-dependent signaling pathways were involved in the activation of NF-κB by M. gallisepticum LAMPs. Together, these results provide evidence that M. gallisepticum LAMPs activate IL-1β production through the NF-κB pathway via TLR2 and MyD88.

Inhibition of LPS-induced inflammatory mediators by 3-hydroxyanthranilic acid in macrophages through suppression of PI3K/NF-κB signaling pathways

Many tryptophan metabolites have immunomodulatory effects on various immune cells. 3-Hydroxyanthranilic Acid (3-HAA) is a tryptophan metabolite reported to have anti-inflammatory activity. The mechanism of this activity is unclear. The present study examined the immunomodulatory effects and molecular mechanisms of 3-HAA on macrophages. Pretreatment of 3-HAA (0.1-10 μg mL(-1)) for 2 h markedly inhibited NO and cytokine production in LPS-stimulated Raw 264.7 cells. Moreover, translocation and activation of NF-κB by LPS in the nucleus were abrogated through the prevention of IκB degradation by 3-HAA treatment. 3-HAA significantly suppressed LPS-induced PI3K/Akt/mTOR activation, whereas MAPKs were not affected by 3-HAA treatment. Furthermore, the inhibition of mTOR by 3-HAA resulted in decreased production of inflammatory mediators and NF-κB activity. Similar results were also observed in primary peritoneal macrophages. Furthermore, 3-HAA modulated macrophage polarization. Collectively, the results suggest that 3-HAA has an immunomodulatory effect that may result from inhibition of PI3K/Akt/mTOR and NF-κB activation, thereby decreasing the production of pro-inflammatory mediators.

PKCα-LSD1-NF-κB-Signaling Cascade Is Crucial for Epigenetic Control of the Inflammatory Response

The inflammatory response mediated by nuclear factor κB (NF-κB) signaling is essential for host defense against pathogens. Although the regulatory mechanism of NF-κB signaling has been well studied, the molecular basis for epigenetic regulation of the inflammatory response is poorly understood. Here we identify a new signaling axis of PKCα-LSD1-NF-κB, which is critical for activation and amplification of the inflammatory response. In response to excessive inflammatory stimuli, PKCα translocates to the nucleus and phosphorylates LSD1. LSD1 phosphorylation is required for p65 binding and facilitates p65 demethylation, leading to enhanced stability. In vivo genetic analysis using Lsd1^SA/SA mice with ablation of LSD1 phosphorylation and chemical approaches in wild-type mice with inhibition of PKCα or LSD1 activity show attenuated sepsis-induced inflammatory lung injury and mortality. Together, we demonstrate that the PKCα-LSD1-NF-κB signaling cascade is crucial for epigenetic control of the inflammatory response, and targeting this signaling could be a powerful therapeutic strategy for systemic inflammatory diseases, including sepsis.

Methanol extract of Guettarda speciosa Linn. inhibits the production of inflammatory mediators through the inactivation of Syk and JNK in macrophages

Guettarda speciosa Linn. (G. speciosa, Rubiaceae) has been used as a traditional medicinal plant in Asia for the treatment of various inflammatory conditions, including cough, fever and maternal postpartum infection. However, the mechanisms underlying the anti‑inflammatory action of G. speciosa extracts have remained elusive. In the present study, the anti‑inflammatory effects of the methanol extract of G. speciosa (MGS) were investigated in murine macrophages by measuring the production of inflammatory mediators and the underlying mechanisms of action by performing immunoblotting analysis of proteins that are potentially involved. MGS reduced nitric oxide (NO) production through regulation of the expression of inducible NO synthase (iNOS) in lipopolysaccharide‑activated RAW 264.7 cells; however, cyclooxygenase‑2, the enzyme responsible for prostaglandin E2 production, was not affected at the mRNA or protein level. MGS reduced interleukin‑6 (IL‑6) production, but had no effect on tumor necrosis factor (TNF)‑α production. In addition, MGS suppressed the transcription of IL‑6, but not that of IL‑1β and TNF‑α. The effect of MGS on proinflammatory mediators resulted from the inhibition of the activation of spleen tyrosine kinase and c‑Jun N‑terminal kinase. In conclusion, the present study suggested that MGS may be a potential candidate for development as a therapeutic for alleviating inflammation.

Regulation of the intestinal tight junction by natural polyphenols: A mechanistic perspective

Impairment of the epithelial barrier function is closely linked to the pathogenesis of various gastrointestinal diseases, food allergies, type I diabetes, and other systematic diseases. Plant-derived polyphenols are natural secondary metabolites and exert various physiological benefits, including anti-inflammatory, anti-oxidative, anti-carcinogenic, and anti-aging effects. Recent studies also show the role of plant polyphenols in regulation of the intestinal barrier and prevention of intestinal inflammatory diseases. Here we summarize the regulatory pathways and mediators linking polyphenols to their beneficial effects on tight junction and gut epithelial barrier functions, and provide useful information about using polyphenols as nutraceuticals for intestinal diseases.

Targeting PP2A and proteasome activity ameliorates features of allergic airway disease in mice

BACKGROUND

Asthma is an allergic airway disease (AAD) caused by aberrant immune responses to allergens. Protein phosphatase-2A (PP2A) is an abundant serine/threonine phosphatase with anti-inflammatory activity. The ubiquitin proteasome system (UPS) controls many cellular processes, including the initiation of inflammatory responses by protein degradation. We assessed whether enhancing PP2A activity with fingolimod (FTY720) or 2-amino-4-(4-(heptyloxy) phenyl)-2-methylbutan-1-ol (AAL_(S) ), or inhibiting proteasome activity with bortezomib (BORT), could suppress experimental AAD.

METHODS

Acute AAD was induced in C57BL/6 mice by intraperitoneal sensitization with ovalbumin (OVA) in combination with intranasal (i.n) exposure to OVA. Chronic AAD was induced in mice with prolonged i.n exposure to crude house dust mite (HDM) extract. Mice were treated with vehicle, FTY720, AAL_(S) , BORT or AAL_(S) +BORT and hallmark features of AAD assessed.

RESULTS

AAL_(S) reduced the severity of acute AAD by suppressing tissue eosinophils and inflammation, mucus-secreting cell (MSC) numbers, type 2-associated cytokines (interleukin (IL)-33, thymic stromal lymphopoietin, IL-5 and IL-13), serum immunoglobulin (Ig)E and airway hyper-responsiveness (AHR). FTY720 only suppressed tissue inflammation and IgE. BORT reduced bronchoalveolar lavage fluid (BALF) and tissue eosinophils and inflammation, IL-5, IL-13 and AHR. Combined treatment with AAL_(S) +BORT had complementary effects and suppressed BALF and tissue eosinophils and inflammation, MSC numbers, reduced the production of type 2 cytokines and AHR. AAL_(S) , BORT and AAL_(S) +BORT also reduced airway remodelling in chronic AAD.

CONCLUSION

These findings highlight the potential of combination therapies that enhance PP2A and inhibit proteasome activity as novel therapeutic strategies for asthma.

The role of Nuclear Factor-kappa B signaling in human cervical cancer

Background The Nuclear Factor kappaB (NF-kB) family consists of transcription factors that play a complex and essential role in the regulation of immune responses and inflammation. NF-kB has recently generated considerable interest as it has been implicated in human cancer initiation, progression and resistance to treatment. In the present comprehensive review the different aspects of NF-kB signaling in the carcinogenesis of cancer of the uterine cervix are discussed. NF-kB functions as part of a network, which determines the pattern of its effects on the expression of several other genes (such as crosstalks with reactive oxygen species, p53, STAT3 and miRNAS) and thus its function. Activation of NF-kB triggered by a HPV infection is playing an important role in the innate and adaptive immune response of the host. The virus induces down regulation of NF-kB to liquidate the inhibitory activity for its replication triggered by the immune system leading a status of persistant HPV infection. During the progression to high grade intraepithelial neoplasia and cervical cancer NF-KB becomes constitutionally activated again. Mutations in NF-kB genes are rare in solid tumors but mutations of upstream signaling molecules such as RAS, EGFR, PGF, HER2 have been implicated in elevated NF-kB signaling. NF-kB can stimulate transcription of proliferation regulating genes (eg. cyclin D1 and c-myc), genes involved in metastasis, VEGF dependent angiogenesis and cell immortality by telomerase. NF-kB activation can also induce the expression of activation-induced cytodine deaminase (AID) and the APOBEC proteins, providing a mechanistic link between the NF-kB pathway and mutagenic characteristic of cervical cancer. Inhibition of NF-kB has the potential to be used to reverse resistance to radiotherapy and systemic anti-cancer medication, but currently no clinicaly active NF-kB targeting strategies are available.

Increased Nuclear Factor-κB/RelA Expression Levels in Human Colorectal Carcinoma in North Indian Patients

Colorectal cancer is a major cause of cancer-related death in many countries. Inflammatory pathway is considered to play a major role in colorectal carcinogenesis. Nuclear factor kappa B (NF-κB) pathway is a link between inflammation and cancer. NF-κB is a transcription factor which belongs to the Rel family. Activation of NF-κB has been shown to play a role in cell proliferation, apoptosis, cytokine production, and oncogenesis. The aim of the present study was to evaluate the expression levels of NF-κB/RelA in colorectal carcinoma using Real-time PCR. For this study, tumor tissue was taken from general surgery OT of PGIMER, Chandigarh from twenty-seven patients of colorectal cancer treated by surgery. Adjacent colonic mucosa specimens were also collected from all patients as normal control tissue. Real-time PCR was performed to determine the nuclear factor-κB/RelA expression levels in twenty-seven pairs of colorectal adenocarcinoma and adjacent normal colonic tissues. Out of 27 CRC patients, 18 were males and 9 females. Mean age of patients was 51.1 ± 14.8 years. Most of the cases were males (67%). Seventy percent of the cases were early (I-II) and 30% were advanced (III-IV) tumor stage. The quantitative relative expression of NF-kB mRNA was found to be significantly higher (p < 0.05) in CRC tissues as compared with that in adjacent normal colon tissues. From this study, we can conclude that RelA/NF-kB pathway is expressed constitutively in colorectal adenoma and adenocarcinomas. Thus, RelA/NF-kB might play an important role in colorectal tumorigenesis.

RNA Sequencing of Murine Norovirus-Infected Cells Reveals Transcriptional Alteration of Genes Important to Viral Recognition and Antigen Presentation

Viruses inherently exploit normal cellular functions to promote replication and survival. One mechanism involves transcriptional control of the host, and knowledge of the genes modified and their molecular function can aid in understanding viral-host interactions. Norovirus pathogenesis, despite the recent advances in cell cultivation, remains largely uncharacterized. Several studies have utilized the related murine norovirus (MNV) to identify innate response, antigen presentation, and cellular recognition components that are activated during infection. In this study, we have used next-generation sequencing to probe the transcriptomic changes of MNV-infected mouse macrophages. Our in-depth analysis has revealed that MNV is a potent stimulator of the innate response including genes involved in interferon and cytokine production pathways. We observed that genes involved in viral recognition, namely IFIH1, DDX58, and DHX58 were significantly upregulated with infection, whereas we observed significant downregulation of cytokine receptors (Il17rc, Il1rl1, Cxcr3, and Cxcr5) and TLR7. Furthermore, we identified that pathways involved in protein degradation (including genes Psmb3, Psmb4, Psmb5, Psmb9, and Psme2), antigen presentation, and lymphocyte activation are downregulated by MNV infection. Thus, our findings illustrate that MNV induces perturbations in the innate immune transcriptome, particularly in MHC maturation and viral recognition that can contribute to disease pathogenesis.

Malaria pigment stimulates chemokine production by human microvascular endothelium

Severe falciparum malaria is characterized by the sequestration of infected erythrocytes and leukocyte recruitment in the microvasculature, resulting in impaired blood flow and metabolic disturbances. Which parasite products cause chemokine production, thus contributing to the strong host inflammatory response and cellular recruitment are not well characterized. Here, we studied haemozoin (Hz), the end-product of haem, a ferriprotoporphyrin-IX crystal bound to host and parasite lipids, DNA, and proteins. We found that natural Hz isolated from Plasmodium falciparum cultures induces CXCL8 and CCL5 production in human dermal microvascular endothelial cells (HMEC-1) in a time-dependent manner. This up-regulation is not caused by haem but rather by Hz-generated lipoperoxidation products (15-HETE) and fibrinogen associated to Hz, and is, at least in part, triggered by the activation of NF-κB, as it was significantly inhibited by artemisinin and other NF-κB pathway inhibitors.

Patchoulene Epoxide Isolated from Patchouli Oil Suppresses Acute Inflammation through Inhibition of NF-κB and Downregulation of COX-2/iNOS

According to the GC-MS analysis, compositional variation was observed between samples of patchouli oil, of which an unknown compound identified as patchoulene epoxide (PAO) was found only in the long-stored oil, whose biological activity still remains unknown. Therefore, the present study aimed to evaluate the potential anti-inflammatory activity with three in vivo inflammatory models: xylene-induced ear edema, acetic acid-induced vascular permeability, and carrageenan-induced paw edema. Further investigation into its underlying mechanism on carrageenan-induced paw edema was conducted. Results demonstrated that PAO significantly inhibited the ear edema induced by xylene, lowered vascular permeability induced by acetic acid and decreased the paw edema induced by carrageenan. Moreover, PAO markedly decreased levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE₂), and nitric oxide (NO), but increased levels of interleukin-4 (IL-4) and interleukin-10 (IL-10). PAO was also shown to significantly downregulate the protein and mRNA expressions of cyclooxygenase-2 (COX-2) and inducible nitric-oxide synthase (iNOS). Western blot analysis revealed that PAO remarkably inhibited p50 and p65 translocation from the cytosol to the nucleus by suppressing IKKβ and IκBα phosphorylation. In conclusion, PAO exhibited potent anti-inflammatory activity probably by suppressing the activation of iNOS, COX-2 and NF-κB signaling pathways.

Beauvericin, a cyclic peptide, inhibits inflammatory responses in macrophages by inhibiting the NF-κB pathway

Beauvericin (BEA), a cyclic hexadepsipeptide produced by the fungus Beauveria bassiana, is known to have anti-cancer, anti-inflammatory, and anti-microbial actions. However, how BEA suppresses macrophage-induced inflammatory responses has not been fully elucidated. In this study, we explored the anti-inflammatory properties of BEA and the underlying molecular mechanisms using lipopolysaccharide (LPS)-treated macrophage-like RAW264.7 cells. Levels of nitric oxide (NO), mRNA levels of transcription factors and the inflammatory genes inducible NO synthase (iNOS) and interleukin (IL)-1, and protein levels of activated intracellular signaling molecules were determined by Griess assay, semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), luciferase reporter gene assay, and immunoblotting analysis. BEA dose-dependently blocked the production of NO in LPS-treated RAW264.7 cells without inducing cell cytotoxicity. BEA also prevented LPS-triggered morphological changes. This compound significantly inhibited nuclear translocation of the NF-κB subunits p65 and p50. Luciferase reporter gene assays demonstrated that BEA suppresses MyD88-dependent NF-κB activation. By analyzing upstream signaling events for NF-κB activation and overexpressing Src and Syk, these two enzymes were revealed to be targets of BEA. Together, these results suggest that BEA suppresses NF-κB-dependent inflammatory responses by suppressing both Src and Syk.

Immunoproteasome deficiency alters microglial cytokine response and improves cognitive deficits in Alzheimer's disease-like APPPS1 mice

The immunoproteasome (iP) represents a specialized type of proteasomes, which plays an important role in the clearance of oxidant-damaged proteins under inflammatory and pathological conditions determining the outcome of various diseases. In Alzheimer’s disease (AD)-like APPPS1 mice Aβ-deposition is paralleled by iP upregulation, most likely mediated through type I interferon induction. To define the impact of increased iP expression we crossed APPPS1 mice with mice deficient in the iP subunit LMP7 resulting in impaired iP function. While LMP7 deficient APPPS1 mice showed no major change in cerebral Aβ-pathology, we observed an altered cytokine response in microglia isolated from LMP7 deficient APPPS1 mice compared to LMP7 expressing APPPS1 control mice. The altered microglial cytokine profile upon iP deficiency in the presence of extracellular Aβ-pathology was associated with an improvement of Aβ-associated cognitive deficits typically present in APPPS1 mice. Our findings suggest a role for iP in the regulation of the innate immune response towards extracellular Aβ-pathology and indicate that inhibition of iP function can modulate the cognitive phenotype upon overexpression of Aβ.

Formoterol and fluticasone propionate combination improves histone deacetylation and anti-inflammatory activities in bronchial epithelial cells exposed to cigarette smoke

BACKGROUND

The addition of long-acting beta2-agonists (LABAs) to corticosteroids improves asthma control. Cigarette smoke exposure, increasing oxidative stress, may negatively affect corticosteroid responses. The anti-inflammatory effects of formoterol (FO) and fluticasone propionate (FP) in human bronchial epithelial cells exposed to cigarette smoke extracts (CSE) are unknown.

AIMS

This study explored whether FP, alone and in combination with FO, in human bronchial epithelial cellline (16-HBE) and primary bronchial epithelial cells (NHBE), counteracted some CSE-mediated effects and in particular some of the molecular mechanisms of corticosteroid resistance.

METHODS

16-HBE and NHBE were stimulated with CSE, FP and FO alone or combined. HDAC3 and HDAC2 activity, nuclear translocation of GR and NF-κB, pERK1/2/tERK1/2 ratio, IL-8, TNF-α, IL-1β mRNA expression, and mitochondrial ROS were evaluated. Actin reorganization in neutrophils was assessed by fluorescence microscopy using the phalloidin method.

RESULTS

In 16-HBE, CSE decreased expression/activity of HDAC3, activity of HDAC2, nuclear translocation of GR and increased nuclear NF-κB expression, pERK 1/2/tERK1/2 ratio, and mRNA expression of inflammatory cytokines. In NHBE, CSE increased mRNA expression of inflammatory cytokines and supernatants from CSE exposed NHBE increased actin reorganization in neutrophils. FP combined with FO reverted all these phenomena in CSE stimulated 16-HBE cells as well as in NHBE cells.

CONCLUSIONS

The present study provides compelling evidences that FP combined with FO may contribute to revert some processes related to steroid resistance induced by oxidative stress due to cigarette smoke exposure increasing the anti-inflammatory effects of FP.

Identification of microRNAs associated with medullary thyroid carcinoma by bioinformatics analyses

The present study aimed to investigate the microRNA (miRNA) profile in human medullary thyroid carcinoma (MTC) tissue. The GSE40807 data profile was downloaded from the Gene Expression Omnibus database. Following preprocessing, differentially expressed microRNAs (DEMs) between MTC and healthy tissues were identified. Based on the obtained DEMs, transcription factor (TF)‑miRNA and miRNA‑target gene regulatory association pairs were predicted. Finally, functional enrichment analysis was performed on target genes of DEMs. Fifteen upregulated and 17 downregulated DEMs were identified. In the constructed TF‑miRNA regulatory network, hsa‑miR‑9‑5p was regulated by 9 TFs and hsa‑miR‑1 was regulated by 8 TFs. TFs of nuclear factor of κ light polypeptide gene enhancer in B‑cells 1 (NF‑κB1) and v‑myc avian myelocytomatosis viral oncogene homolog (MYC) regulated 4 and 3 DEMs, respectively. In the miRNA‑target gene regulatory network, hsa‑miR‑1, hsa‑miR‑9‑5p, hsa‑miR‑96‑5p and hsa‑miR‑590‑5p were most upregulated. The target genes of these 4 miRNAs were primarily enriched in the mitogen activated protein kinase (MAPK) signaling pathway. Therefore, MAPK signaling pathway may serve important roles in MTC progression. In conclusion, the DEMs hsa‑miR‑1 and hsa‑miR‑9‑5p, and TFs of NF‑κB1 and MYC may be used as biomarkers for the diagnosis and treatment of MTC.

Helicobacter pylori-induced cell death is counteracted by NF-κB-mediated transcription of DARPP-32

OBJECTIVE

DARPP-32 is a frequently amplified and overexpressed gene that promotes several oncogenic functions in gastric cancer. Herein, we investigated the relationship between Helicobacter pylori infection, proinflammatory NF-κB activation and regulation of DARPP-32.

DESIGN

The study used in vivo and in vitro experiments. Luciferase reporter, quantitative real-time PCR, immunoblot, chromatin immunoprecipitation (ChIP), cell viability, H. pylori infection, tissue microarrays and immunohistochemical assays were used.

RESULTS

Our results indicated that H. pylori infection increased the DARPP-32 mRNA and protein levels in gastric cancer cell lines and gastric mucosa of mice. H. pylori infection increased the activity of NF-κB reporter and p-NF-κB (S536) protein level in vitro and in vivo. To investigate the transcriptional regulation of DARPP-32, we cloned a 3019 bp of the DARPP-32 promoter into the luciferase reporter (pGL3-Luc). Both H. pylori infection and tumour necrosis factor-α treatment induced DARPP-32 reporter activity (p<0.01). Using deletion constructs of DARPP-32 promoter and ChIP assay, we demonstrated that the sequence -996 to -1008 bp containing putative NF-κB-binding sites is the most active region. The induction of DARPP-32 expression by H. pylori infection counteracted H. pylori-induced cell death through activation of serine/threonine-specific protein kinase (AKT), as determined by ATP-Glo and clonogenic survival assays. Immunohistochemistry analysis demonstrated a significant positive correlation between NF-κB and DARPP-32 expression levels in gastric cancer tissues (r²=0.43, p<0.01).

CONCLUSIONS

Given the high frequency of DARPP-32 overexpression and its prosurvival oncogenic functions, the induction of DARPP-32 expression following H. pylori infection and activation of NF-κB provides a link between infection, inflammation and gastric tumourigenesis.

N-methyl pyrrolidone (NMP) ameliorates the hypoxia-reduced osteoblast differentiation via inhibiting the NF-κB signaling

Ischemic-hypoxic condition for local osteoblasts and bone mesenchymal stem cells during bone fracture inhibits bone repairing. N-methyl pyrrolidone (NMP) has been approved as a safe and biologically inactive small chemical molecule, and might be useful for bone fracture repairing. In the present study, we investigated the effect of NMP on the hypoxia-reduced cellular viability and the expression of differentiation-associated markers, such as bone morphogenetic protein 2 (BMP-2), propeptide of type I procollagen I (PINP), alkaline phosphatase (ALP) or runt-related transcription factor 2 (Runx2) in the osteoblasts, and then we examined the molecular mechanism underlining such effect in the human osteoblastic hFOB 1.19 cells. Our results demonstrated that NMP significantly blocked the hypoxia-induced cell viability reduction and inhibited the hypoxia-caused expression downregulation of BMP-2, PINP, ALP and Runx2 in hFOB 1.19 cells. Then we confirmed the involvement of nuclear factor κB (NF-κB) pathway in the regulation by NMP on the hypoxia-mediated the reduction of osteoblast differentiation. The upregulated expression and transcriptional activity of NF-κB, while the downregulated inhibitory κB expression by the hypoxia treatment was reversed by the treatment with 10 mM NMP. In conclusion, our study found a protective role of NMP in osteoblast differentiation in response to hypoxia, and such protection was through inhibiting the NF-κB signaling. This suggests that NMP might be a protective agent in bone fracture repairing.

Olive oil bioactives protect pigs against experimentally-induced chronic inflammation independently of alterations in gut microbiota

Subclinical chronic inflammation (SCI) is associated with impaired animal growth. Previous work has demonstrated that olive-derived plant bioactives exhibit anti-inflammatory properties that could possibly counteract the growth-depressing effects of SCI. To test this hypothesis and define the underlying mechanism, we conducted a 30-day study in which piglets fed an olive-oil bioactive extract (OBE) and their control counterparts (C+) were injected repeatedly during the last 10 days of the study with increasing doses of Escherichia coli lipopolysaccharides (LPS) to induce SCI. A third group of piglets remained untreated throughout the study and served as a negative control (C-). In C+ pigs, SCI increased the circulating concentration of interleukin 1 beta (p < 0.001) and decreased feed ingestion (p < 0.05) and weight gain (p < 0.05). These responses were not observed in OBE animals. Although intestinal inflammation and colonic microbial ecology was not altered by treatments, OBE enhanced ileal mRNA abundance of tight and adherens junctional proteins (p < 0.05) and plasma recovery of mannitol (p < 0.05) compared with C+ and C-. In line with these findings, OBE improved transepithelial electrical resistance (p < 0.01) in TNF-α-challenged Caco-2/TC-7 cells, and repressed the production of inflammatory cytokines (p < 0.05) in LPS-stimulated macrophages. In summary, this work demonstrates that OBE attenuates the suppressing effect of SCI on animal growth through a mechanism that appears to involve improvements in intestinal integrity unrelated to alterations in gut microbial ecology and function.

The viral innate immune antagonism and an alternative vaccine design for PRRS virus

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PRRS virus has evolved to suppress the antiviral innate immunity during infection.

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Type I interferons are potent antiviral cytokines and function to stimulate the adaptive immune responses.

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Six viral proteins have been identified as interferon antagonists and characterized for their molecular actions.

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Interferon antagonism-negative viruses are attenuated and have been proven induce protective immunity.

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Interferon suppression-negative PRRS virus may serve as an alternative vaccine for PRRS.

Porcine reproductive and respiratory syndrome (PRRS) remains one of the most economically significant diseases in the swine industry worldwide. The current vaccines are less satisfactory to confer protections from heterologous infections and long-term persistence, and the need for better vaccines are urgent. The immunological hallmarks in PRRSV-infected pigs include the unusually poor production of type I interferons (IFNs-α/β) and the aberrant and delayed adaptive immune responses, indicating that PRRSV has the ability to suppress both innate and adaptive immune responses in the host. Type I IFNs are the potent antiviral cytokines and recent studies reveal their pleiotropic functions in the priming of expansion and maturation of adaptive immunity. Thus, IFN antagonism-negative PRRSV is hypothesized to be attenuated and to build effective and broad- spectrum innate and adaptive immune responses in pigs. Such vaccines are promising alternatives to traditional vaccines for PRRSV.

Pro-inflammatory Signaling in a 3D Organotypic Skin Model after Low LET Irradiation-NF-κB, COX-2 Activation, and Impact on Cell Differentiation

Nearly 85% of radiotherapy patients develop acute radiation dermatitis, which is an inflammatory reaction of the skin at the treatment field and in the surrounding area. The aims of this study were to unravel the mechanisms of radiation-induced inflammatory responses after localized irradiation in a human 3D organotypic skin culture model. This could provide possible inflammatory targets for reduction of skin side effects. 3D organotypic skin cultures were set up and locally irradiated with 225 kVp X-rays, using a combination of full exposure and partial shielding (50%) of the cultures. The secretion of pro-inflammatory cytokines, the phenotype, and the differentiation markers expression of the cultures were assessed up to 10 days postirradiation. The pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX-2) pathways have been studied. The results showed fast activation of NF-κB, most likely triggered by DNA damage in the irradiated cells, followed by upregulation of p38 MAPK and COX-2 in the irradiated and surrounding, non-irradiated, areas of the 3D cultures. The application of the COX-2 inhibitor sc-236 was effective at reducing the COX-2 mRNA levels 4 h postirradiation. The same inhibitor also suppressed the PGE2 secretion significantly 72 h after the treatment. The expression of a pro-inflammatory phenotype and abnormal differentiation markers of the cultures were also reduced. However, the use of an NF-κB inhibitor (Bay 11-7085) did not have the predicted positive effect on the cultures phenotype postirradiation. Radiation-induced pro-inflammatory responses have been observed in the 3D skin model. The activated signaling pathways involved NF-κB transcription factor and its downstream target COX-2. Further experiments aiming to suppress the inflammatory response via specific inhibitors showed that COX-2 is a suitable target for reduction of the normal skin inflammatory responses at radiotherapy, while NF-κB inhibition had detrimental effects on the 3D skin model development.

Chlorin e6-Mediated Photodynamic Therapy Suppresses P. acnes-Induced Inflammatory Response via NFκB and MAPKs Signaling Pathway

Photodynamic therapy (PDT), consisting of photosensitizer, light, and oxygen has been used for the treatment of various diseases including cancers, microbial infections and skin disorders. In this study, we examined the anti-inflammatory effect of chlorin e6-mediated PDT in P. acnes-infected HaCaT cells using photosensitizer chlorin e6 (Ce6) and halogen light. The live and heat-killed P. acnes triggered an upregulation of inflammatory molecules such as iNOS, NO, and inflammatory cytokine in HaCaT cells and mouse model. Ce6-mediated PDT notably downregulated the expression of these inflammatory molecules in vitro and in vivo. Similarly, chlorin e6-mediated PDT was capable of regulating inflammatory response in both live and heat killed S. epidermidis exposed HaCaT cells. Moreover, phosphorylation of p38, JNK, and ERK were reduced by Ce6-mediated PDT. Ce6-mediated PDT also reduced the phosphorylation of IKKα/β, IĸBα and NFκB p65 in P. acnes-stimulated HaCaT cells. In addition, the dramatic increase in the nuclear translocation of NFκB p65 observed upon stimulation with P. acnes was markedly impaired by Ce6-based PDT. This is the first suggestion that Ce6-mediated PDT suppresses P. acnes-induced inflammation through modulating NFκB and MAPKs signaling pathways.

NF-κB activation is critical for bacterial lipoprotein tolerance-enhanced bactericidal activity in macrophages during microbial infection

Tolerance to bacterial components represents an essential regulatory mechanism during bacterial infection. Bacterial lipoprotein (BLP)-induced tolerance confers protection against microbial sepsis by attenuating inflammatory responses and augmenting antimicrobial activity in innate phagocytes. It has been well-documented that BLP tolerance-attenuated proinflammatory cytokine production is associated with suppressed TLR2 signalling pathway; however, the underlying mechanism(s) involved in BLP tolerance-enhanced antimicrobial activity is unclear. Here we report that BLP-tolerised macrophages exhibited accelerated phagosome maturation and enhanced bactericidal activity upon bacterial infection, with upregulated expression of membrane-trafficking regulators and lysosomal enzymes. Notably, bacterial challenge resulted in a strong activation of NF-κB pathway in BLP-tolerised macrophages. Importantly, activation of NF-κB pathway is critical for BLP tolerance-enhanced antimicrobial activity, as deactivation of NF-κB in BLP-tolerised macrophages impaired phagosome maturation and intracellular killing of the ingested bacteria. Finally, activation of NF-κB pathway in BLP-tolerised macrophages was dependent on NOD1 and NOD2 signalling, as knocking-down NOD1 and NOD2 substantially inhibited bacteria-induced activation of NF-κB and overexpression of Rab10 and Acp5, two membrane-trafficking regulators and lysosomal enzymes contributed to BLP tolerance-enhanced bactericidal activity. These results indicate that activation of NF-κB pathway is essential for BLP tolerance-augmented antimicrobial activity in innate phagocytes and depends primarily on both NOD1 and NOD2.

2-Hydroxy-3-methoxybenzoic acid attenuates mast cell-mediated allergic reaction in mice via modulation of the FcεRI signaling pathway

Mast cells are important effector cells in immunoglobulin (Ig) E-mediated allergic reactions such as asthma, atopic dermatitis and rhinitis. Vanillic acid, a natural product, has shown anti-oxidant and anti-inflammatory activities. In the present study, we investigated the anti-allergic inflammatory effects of ortho-vanillic acid (2-hydroxy-3-methoxybenzoic acid, o-VA) that was a derivative of vanillic acid isolated from Amomum xanthioides. In mouse anaphylaxis models, oral administration of o-VA (2, 10, 50 mg/kg) dose-dependently attenuated ovalbumin-induced active systemic anaphylaxis and IgE-mediated cutaneous allergic reactions such as hypothermia, histamine release, IgE production and vasodilation; administration of o-VA also suppressed the mast cell degranulator compound 48/80-induced anaphylaxis. In cultured mast cell line RBL-2H3 and isolated rat peritoneal mast cells in vitro, pretreatment with o-VA (1-100 μmol/L) dose-dependently inhibited DNP-HSA-induced degranulation of mast cells by decreasing the intracellular free calcium level, and suppressed the expression of pro-inflammatory cytokines TNF-α and IL-4. Pretreatment of RBL-2H3 cells with o-VA suppressed DNP-HSA-induced phosphorylation of Lyn, Syk, Akt, and the nuclear translocation of nuclear factor-κB. In conclusion, o-VA suppresses the mast cell-mediated allergic inflammatory response by blocking the signaling pathways downstream of high affinity IgE receptor (FcεRI) on the surface of mast cells.

Alternative Interventions to Prevent Oxidative Damage following Ischemia/Reperfusion

Ischemia/reperfusion (I/R) lesions are a phenomenon that occurs in multiple pathological states and results in a series of events that end in irreparable damage that severely affects the recovery and health of patients. The principal therapeutic approaches include preconditioning, postconditioning, and remote ischemic preconditioning, which when used separately do not have a great impact on patient mortality or prognosis. Oxidative stress is known to contribute to the damage caused by I/R; however, there are no pharmacological approaches to limit or prevent this. Here, we explain the relationship between I/R and the oxidative stress process and describe some pharmacological options that may target oxidative stress-states.

The Immunological Basis of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are chronic ailments, Crohn's disease and ulcerative colitis being the most important. These diseases present an inflammatory profile and they differ according to pathophysiology, the affected area in the gastrointestinal tract, and the depth of the inflammation in the intestinal wall. The immune characteristics of IBD arise from abnormal responses of the innate and adaptive immune system. The number of Th17 cells increases in the peripheral blood of IBD patients, while Treg cells decrease, suggesting that the Th17/Treg proportion plays an important role in the development and maintenance of inflammation. The purpose of this review was to determine the current state of knowledge on the immunological basis of IBD. Many studies have shown the need for further explanation of the development and maintenance of the inflammatory process.