Regulation of the NF-κB-Mediated Transcription of Inflammatory Genes

How Does Herbal Medicine Treat Idiopathic Membranous Nephropathy?

Idiopathic membranous nephropathy (IMN) has made increasing progress in mechanism and treatment research. Herbal medicine is gradually being accepted as an alternative therapy in treating IMN. However, the intervention mechanism of herbal medicine in the treatment of membranous nephropathy is still unclear. In this review, we summarize some achievements of herb medicine in treating IMN and discuss the research direction of herb in IMN. Finally, we propose the dilemma about the study on the treatment of IMN with herb medicine. We hope that this article can bring some thoughts for clinical and scientific researchers on the treatment of IMN with herb medicine.

COVID-19, an opportunity to reevaluate the correlation between long-term effects of anthropogenic pollutants on viral epidemic/pandemic events and prevalence

Occupational, residential, dietary and environmental exposures to mixtures of synthetic anthropogenic chemicals after World War II have a strong relationship with the increase of chronic diseases, health cost and environmental pollution. The link between environment and immunity is particularly intriguing as it is known that chemicals and drugs can cause immunotoxicity (e.g., allergies and autoimmune diseases). In this review, we emphasize the relationship between long-term exposure to xenobiotic mixtures and immune deficiency inherent to chronic diseases and epidemics/pandemics. We also address the immunotoxicologic risk of vulnerable groups, taking into account biochemical and biophysical properties of SARS-CoV-2 and its immunopathological implications. We particularly underline the common mechanisms by which xenobiotics and SARS-CoV-2 act at the cellular and molecular level. We discuss how long-term exposure to thousand chemicals in mixtures, mostly fossil fuel derivatives, exposure toparticle matters, metals, ultraviolet (UV)–B radiation, ionizing radiation and lifestyle contribute to immunodeficiency observed in the contemporary pandemic, such as COVID-19, and thus threaten global public health, human prosperity and achievements, and global economy. Finally, we propose metrics which are needed to address the diverse health effects of anthropogenic COVID-19 crisis at present and those required to prevent similar future pandemics.

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Developmental exposure to environmental factors can disrupt the immune system.

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Long-term low-dose exposure to chemical mixtures is linked to imunodeficiency

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Immunodeficiency contributes to chronic diseases and the current Covid-19 pandemics.

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Environmental chemicals and microorganisms share similar molecular pathomechanisms (AhR pathway).

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Understanding the underlying pathomechanisms helps to improve public health.

Regulation of DNA methylation signatures on NF-κB and STAT3 pathway genes and TET activity in cigarette smoke extract-challenged cells/COPD exacerbation model in vitro

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a global health problem. Currently, there is a lack of knowledge about the pathobiology of this disease and available therapies are ineffective. Cigarette smoking is the leading cause of COPD; however, not all smokers develop COPD. Exacerbations of COPD caused by microbes are common and detrimental. Approximately 20-50% of patient exacerbations are caused by bacterial colonization in the lower airways. It is generally accepted that epigenetic mechanisms, especially DNA methylation, play an important role during progression of COPD. Thus, we hypothesized that DNA methylation patterns vary significantly following smoke exposure and during exacerbations caused by bacterial infections. To test our hypothesis, we used an in vitro study model that mimics COPD exacerbations and performed extensive studies to understand the role of CpG promoter methylation of NF-κB and STAT3-mediated pathway genes. Both NF-κB and STAT3 transcription factors play critical roles in orchestrating inflammatory responses during cigarette smoke exposure. In brief, human lung adenocarcinoma cells with type II alveolar epithelium characteristics (A549) were challenged with cigarette smoke extract (CSE) or DMSO (control) followed by a 3-h challenge with bacterial lipopolysaccharide (LPS; from Pseudomonas aeruginosa) prior to the termination of CSE exposure (COPD exacerbation group). The production of cytokines/chemokines, regulation of transcription factors, and DNA methylation of specific genes were then assessed. We also studied changes in the expression and activity of ten-eleven translocases (TETs), the enzymes responsible for DNA demethylation, and assessed their role in regulating DNA methylation in the CSE-challenged group.

RESULTS

There was a significant increase in the release of cytokines/chemokines (IL-8, MCP-1, IL-6 and CCL5) in the COPD exacerbation group as compared to the control group. Hypomethylation of NF-κB-mediated pathway genes correlated with their induction in our COPD exacerbation study model. Further, we observed an important role of TET1/2 in regulating the DNA methylation of NF-κB, STAT3, IKK, and NIK genes and cytokine/chemokine production by A549 cells during CSE challenge.

CONCLUSIONS

Studies to further define the role of TETs in CSE-mediated epigenetic regulation may lead to the development of better and more effective therapeutic intervention strategies for COPD.

Diurnal rhythm expression of transcription factor NF-κB subunit p65 in Pelteobagrus vachellii

The pleiotropic transcription factor nuclear factor-kappa B (NF-κB) has important functions in viral resistance. In the present study, we isolated a p65 subunit of NF-κB cDNA from Pelteobagrus vachellii (termed Pvp65) and characterized it. The full-length p65 cDNA comprised 3651 bp, including a 148-bp 5'-untranslated region (UTR), a 106-bp 3'-UTR, and an open reading frame encoding a 1067-amino acid putative protein. The protein sequence comprised a DNA binding motif, a Rel-homology domain, a Rel protein signature, a putative transcription activation domain, a nuclear localization signal, and a transcription initiation factor IIA domain. The expression of Pvp65 displayed a daily rhythm, with an acrophase at approximately at 15:32 h in the liver, 11:34 h in the spleen, and 16:45 h in the head kidney. In addition, infection with Aeromonas hydrophila caused Pvp65 expression to increase significantly (P < 0.05), and peaking at 12 h post infection in the spleen, at 24 in the head kidney, and at 12 h in the liver. Thus, NF-κB expression might be under light/dark cycle control in P. vachellii, and may be involved in the immune response to A. hydrophila.

25-Hydroxyvitamin D3 positively regulates periodontal inflammaging via SOCS3/STAT signaling in diabetic mice

BACKGROUND

Diabetes is a known age-related disease. Inflammaging has recently been shown to result in diabetic complications. Vitamin D₃ is related to aging in the latest study but little is known about the underlying mechanism. Here, we investigated the effects of 25-Hydroxyvitamin D₃ (25(OH)D₃) on inflammaging in diabetic periodontitis, a common chronic inflammatory diabetic complication.

EXPERIMENTAL DESIGN

A model of Porphyromonas gingivalis-infected db/db mice as experimental type 2 diabetic periodontitis was adopted in the whole study. A range of techniques, including microCT, western blotting, ELISA, histological and immunohistochemical analysis, were carried out in this study. The distinctive senescence-associated secretory phenotype (SASP) in serum was measured by Luminex technology.

RESULTS

We found an archetypal inflammaging status occurred in db/db mice. An increased SASP, senescent enhancement, and periodontal destruction were observed in periodontitis-db/db mice. Upon administration with 25(OH)D₃, periodontitis-db/db mice presented increased levels of serum 25(OH)D₃, 1α,25-Dihydroxyvitamin D₃ and calcium. Moreover, decreased p16/p21-positive cells, relieved periodontal conditions and ameliorated serum SASP secretion were found in the periodontitis-db/db mice after treatment. Gingival tissue exhibited increased level of VDR and decreased expression of SOCS3, p-STAT3/STAT3, p-STAT5/STAT5, NF-κB and IL-1β, which were consistent with the change of p16/p21 expression.

CONCLUSION

Diabetic periodontitis appeared to develop an inflammaging status resulted in periodontal infection. 25(OH)D₃ could inhibit SASP secretion through reducing SOCS3 expression in experimental diabetic periodontitis, dependently inactivating NF-κB pro-inflammatory signaling. The reversible effect further documented that the inflammaging might be a highly likely contributor in diabetic periodontitis.

NF-κB c-Rel Dictates the Inflammatory Threshold by Acting as a Transcriptional Repressor

NF-κB/Rel family of transcription factors plays a central role in initiation and resolution of inflammatory responses. Here, we identified a function of the NF-κB subunit c-Rel as a transcriptional repressor of inflammatory genes. Genetic deletion of c-Rel substantially potentiates the expression of several TNF-α-induced RelA-dependent mediators of inflammation. v-Rel, the viral homologue of c-Rel, but not RelB, also possesses this repressive function. Mechanistically, we found that c-Rel selectively binds to the co-repressor HDAC1 and competitively binds to the DNA mediating HDAC1 recruitment to the promoters of inflammatory genes. A specific point mutation at tyrosine25 in c-Rel's DNA-binding domain, for which a missense single nucleotide variation (Y25H) exists in humans, completely abrogated its ability to bind DNA and repress TNF-α-induced, RelA-mediated transcription. Our findings reveal that the transactivator NF-κB subunit c-Rel also plays a role as a transcriptional repressor in the maintenance of inflammatory homeostasis.

The epigenetically-encoded memory of the innate immune system

Stimulation or infection of innate immune cells induces profound epigenetic changes, including the induction of histone modifications and alterations in DNA methylation levels. While some of these changes are rapidly reversible, others appear to be long-lasting, even in mitotic populations, with important functional consequences for the stimulus-experienced cell. Here we discuss the individual contributions of each of the plethora of known epigenetic modifications to the initial transcriptional response to immune activation, their dynamics as cells return to homeostasis, and their contribution to memory of the initial stimulus.

Prunus serrulata var. spontanea inhibits mast cell activation and mast cell-mediated anaphylaxis

ETHNOPHARMACOLOGICAL RELEVANCE

A promising approach to treat a variety of diseases are considered as complementary and alternative herbal medicines. Prunus serrulata var. spontanea L. (Rosaceae) is used as herbal medicine to treat allergic diseases according to the Donguibogam, a tradition medical book of the Joseon Dynasty in Korea.

AIM OF THE STUDY

We prepared the aqueous extract of the bark of P. serrulata (AEBPS) and aimed to investigate the effects in mouse anaphylaxis models and various types of mast cells, including RBL-2H3, primary cultured peritoneal and bone marrow-derived mast cells.

MATERIALS AND METHODS

We used ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) and immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis (PCA) models, in vivo. The control drug dexamethasone (10 mg/kg) was used to compare the effectiveness of AEBPS (1-100 mg/kg). In vitro, IgE-stimulated mast cells were used to confirm the role of AEBPS (1-100 μg/mL). For statistical analyses, p values less than 0.05 were considered to be significant.

RESULTS

In ASA model, oral administration of AEBPS suppressed the hypothermia and increased level of serum histamine in a dose-dependent manner. AEBPS attenuated the serum IgE, OVA-specific IgE, and interleukin (IL)-4. Oral administration of AEBPS also blocked mast cell-dependent PCA. AEBPS suppressed degranulation of mast cells by reducing intracellular calcium level in mast cells. AEBPS inhibited tumor necrosis factor-α and IL-4 expression and secretion in a concentration-dependent manner through the reduction of nuclear factor-κB.

CONCLUSIONS

On the basis of these findings, AEBPS could serve as a potential therapeutic target for the management of mast cell-mediated allergic inflammation and as a regulator of mast cell activation.

Anti‑inflammatory role of Prunus persica L. Batsch methanol extract on lipopolysaccharide‑stimulated glial cells

Glial cells are the resident immune cells of the central nervous system. Reactive glial cells release inflammatory mediators that induce neurotoxicity or aggravate neurodegeneration. Regulation of glial activation is crucial for the initiation and progression of neuropathological conditions. Constituents of the peach tree (Prunus persica L. Batsch), which has a global distribution, have been found to exert therapeutic effects in pathological conditions, such as rashes, eczema and allergies. However, the therapeutic potential of its aerial parts (leaves, fruits and twigs) remains to be elucidated. The present study aimed to evaluate the anti-inflammatory role of P. persica methanol extract (PPB) on lipopolysaccharide (LPS)-stimulated glial cells. High-performance liquid chromatography coupled with tandem mass spectrometry analysis showed that PPB contained chlorogenic acid and catechin, which have antioxidant properties. Western blot and reverse transcription polymerase chain reaction results indicated that PPB reduced the transcription of various proinflammatory enzymes (nitric oxide synthase and cyclooxygenase-2) and cytokines [tumor necrosis factor-α, interleukin (IL)-1β and IL-6] in LPS-stimulated BV2 cells. In addition, PPB inhibited the activation of NF-κB and various mitogen-activated protein kinases required for proinflammatory mediator transcription. Finally, nitrite measurement and immunocytochemistry results indicated that PPB also suppressed nitrite production and NF-κB translocation in LPS-stimulated primary astrocytes. Thus, PPB may be used as a potential therapeutic agent for neurodegenerative diseases and neurotoxicity via the suppression of glial cell activation.

GRK5 Inhibition Attenuates Cartilage Degradation via Decreased NF-κB Signaling

OBJECTIVE

NF-κB-dependent signaling is an important modulator in osteoarthritis (OA), and G protein-coupled receptor kinase 5 (GRK5) regulates the NF-κB pathway. This study was undertaken to investigate the functional involvement of GRK5 in OA pathogenesis.

METHODS

GRK5 expression in normal and OA human knee joints was analyzed immunohistochemically. Gain- or loss-of-function experiments were performed using human and mouse chondrocytes. OA was induced in GRK5-knockout mice by destabilization of the medial meniscus, and histologic examination was performed. OA was also induced in wild-type mice, which were then treated with an intraarticular injection of amlexanox, a selective GRK5 inhibitor, every 5 days for 8 weeks.

RESULTS

GRK5 protein expression was increased in human OA cartilage. In vitro, expression levels of OA-related factors and NF-κB transcriptional activation were down-regulated by suppression of the GRK5 gene in human OA chondrocytes (3.49-fold decrease in IL6 [P < 0.01], 2.43-fold decrease in MMP13 [P < 0.01], and 2.66-fold decrease in ADAMTS4 [P < 0.01]). Conversely, GRK5 overexpression significantly increased the expression of OA-related catabolic mediators and NF-κB transcriptional activation. On Western blot analysis, GRK5 deletion reduced IκBα phosphorylation (up to 4.4-fold decrease [P < 0.05]) and decreased p65 nuclear translocation (up to 6.4-fold decrease [P < 0.01]) in mouse chondrocytes. In vivo, both GRK5 deletion and intraarticular amlexanox protected mouse cartilage against OA.

CONCLUSION

Our results suggest that GRK5 regulates cartilage degradation through a catabolic response mediated by NF-κB signaling, and is a potential target for OA treatment. Furthermore, amlexanox may be a major compound in relevant drugs.

Induction of autophagy protects human dental pulp cells from lipopolysaccharide-induced pyroptotic cell death

The NOD-like receptor protein 3/caspase-1 inflammasome can be activated in human dental pulp tissue and fibroblasts; however, the underlying mechanisms are poorly understood. In the present study, lipopolysaccharide (LPS) was used to treat dental pulp cells to establish an inflammation model. Cell viability was examined by sulforhodamine B assay. Interleukin (IL)-1β, caspase-1, microtubule-associated protein-1 light chain 3-II/I and p62 were determined by western blotting and ELISA. The phosphorylation (p-) levels of NF-κB and NF-κB inhibitor (IκB)α protein were observed by western blotting. The results demonstrated that LPS induced pyroptotic cell death in cultured dental pulp cells, which was supported by the increased levels of IL-1β, IL-18 and caspase-1. Rapamycin and 3-methyladenine (3-MA) were used to activate and inhibit autophagy, and it was observed that LPS increased autophagy and rapamycin reduced LPS-induced dental pulp cell pyroptosis. However, 3-MA aggravated LPS-induced dental pulp cell pyroptosis. In addition, LPS inhibited the expression of IκBα, but increased the expression of p-NF-κB. Compared with the LPS group, 3-MA further inhibited the expression of IκBα but promoted the expression of p-NF-κB. However, rapamycin produced the opposite results to LPS. Under LPS treatment, the NF-κB pathway inhibitor BAY11-7082 further enhanced the inhibitory effects of rapamycin, but inhibited the promoting effects of 3-MA on the protein expression levels of IL-1β and caspase-1. The results of the present study demonstrated that there is an important crosstalk between autophagy, pyroptosis and the NF-κB pathway, and that the modulation of pyroptosis in dental pulp cells may be a promising strategy to pulpitis therapy.

Trichosanthes tricuspidata Lour. Methanol Extract Exhibits Anti-Inflammatory Activity by Targeting Syk, Src, and IRAK1 Kinase Activity

Trichosanthes tricuspidata Lour., also known as T. palmata Roxb, T. bracteata Lam., T. puber Blume, and Modecca bracteata, is a vine belonging to the Cucurbitaceae family (English name: redball snake gourd). Distributed in China, South and East Asia, and tropical Australia, it has been traditionally used as a medicinal plant for its antifever, laxative, anthelmintic properties and for migraine treatment. In this paper, we examined the effects of Trichosanthes tricuspidata Lour. ethanol extract (Tt-ME) in vitro and in vivo. To confirm the effects of Tt-ME on inflammatory responses, we conducted experimental analyses including level of nitric oxide (NO) production, RT-PCR, and immunoblotting and using a HCl/EtOH-induced gastritis animal model. Tt-ME attenuated the release of NO and decreased mRNA levels of inducible NO synthase (iNOS), TNF-α, and IL-6 in lipopolysaccharide- (LPS-) induced macrophages in a concentration-dependent manner. Tt-ME time-dependently suppressed nuclear translocation of nuclear factor kappa B (NF-κB) subunits p50 and p65, activator protein (AP-1) subunits c-Fos and c-Jun, and STAT3 transcriptional activity by inhibiting nuclear translocation of p50, p65, c-Fos, c-Jun, and STAT3. Tt-ME significantly downregulated NF-κB, MAPK, and JAK2 signaling by targeting Syk, Src, and IRAK1 protein kinases. Furthermore, matrix metalloproteinase-9 (MMP-9) expression and cell migration were observed to be downregulated by Tt-ME in LPS-activated macrophages. In vivo studies on Tt-ME also produced similar trends in Hcl/EtOH-induced gastritis mouse models by inhibiting proinflammatory cytokines and the inflammatory signaling pathway. Our results strongly suggest that Tt-ME exerted anti-inflammatory activity in LPS-stimulated macrophages and mouse models of acute inflammatory disease.

The inflammatory effect of epigenetic factors and modifications in type 2 diabetes

Inflammation has a central role in the etiology of type 2 diabetes (T2D) and its complications. Both genetic and epigenetic factors have been implicated in the development of T2D-associated inflammation. Epigenetic mechanisms regulate the function of several components of the immune system. Diabetic conditions trigger aberrant epigenetic alterations that contribute to the progression of insulin resistance and β-cell dysfunction by induction of inflammatory responses. Thus, targeting epigenetic factors and modifications, as one of the underlying causes of inflammation, could lead to the development of novel immune-based strategies for the treatment of T2D. The aim of this review is to provide an overview of the epigenetic mechanisms involved in the propagation and perpetuation of chronic inflammation in T2D. We also discuss the possible anti-inflammatory approaches that target epigenetic factors for the treatment of T2D.

Genome reading by the NF-κB transcription factors

The NF-κB family of dimeric transcription factors regulates transcription by selectively binding to DNA response elements present within promoters or enhancers of target genes. The DNA response elements, collectively known as κB sites or κB DNA, share the consensus 5'-GGGRNNNYCC-3' (where R, Y and N are purine, pyrimidine and any nucleotide base, respectively). In addition, several DNA sequences that deviate significantly from the consensus have been shown to accommodate binding by NF-κB dimers. X-ray crystal structures of NF-κB in complex with diverse κB DNA have helped elucidate the chemical principles that underlie target selection in vitro. However, NF-κB dimers encounter additional impediments to selective DNA binding in vivo. Work carried out during the past decades has identified some of the barriers to sequence selective DNA target binding within the context of chromatin and suggests possible mechanisms by which NF-κB might overcome these obstacles. In this review, we first highlight structural features of NF-κB:DNA complexes and how distinctive features of NF-κB proteins and DNA sequences contribute to specific complex formation. We then discuss how native NF-κB dimers identify DNA binding targets in the nucleus with support from additional factors and how post-translational modifications enable NF-κB to selectively bind κB sites in vivo.

Beta-cell dysfunction induced by non-cytotoxic concentrations of Interleukin-1β is associated with changes in expression of beta-cell maturity genes and associated histone modifications

Decreased insulin secretory capacity in Type 2 diabetes mellitus is associated with beta-cell dedifferentiation and inflammation. We hypothesize that prolonged exposure of beta-cells to low concentrations of IL-1β induce beta-cell dedifferentiation characterized by impaired glucose-stimulated insulin secretion, reduced expression of key beta-cell genes and changes in histone modifications at gene loci known to affect beta-cell function. Ten days exposure to IL-1β at non-cytotoxic concentrations reduced insulin secretion and beta-cell proliferation and decreased expression of key beta-cell identity genes, including MafA and Ucn3 and decreased H3K27ac at the gene loci, suggesting that inflammatory cytokines directly affects the epigenome. Following removal of IL-1β, beta-cell function was normalized and mRNA expression of beta-cell identity genes, such as insulin and Ucn3 returned to pre-stimulation levels. Our findings indicate that prolonged exposure to low concentrations of IL-1β induces epigenetic changes associated with loss of beta-cell identity as observed in Type 2 diabetes.

Effects of Salvia miltiorrhiza Polysaccharides on Lipopolysaccharide-Induced Inflammatory Factor Release in RAW264.7 Cells

This study investigated the anti-inflammatory effects and possible underlying mechanisms of Salvia miltiorrhiza polysaccharides (SMP) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The cytotoxicity of SMP was detected by the MTT method. The morphological change of RAW264.7 was observed by Diff-Quik staining. Enzyme-linked immunosorbent assay was used to evaluate the production of cytokines in LPS-induced RAW264.7 cells. The nitric oxide (NO) kit assay detected the NO release from LPS-induced RAW264.7 cells. Real-time polymerase chain reaction was used to detect the transcriptions of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), inducible NO synthase (iNOS), and cyclooxygenase (COX)-2 in LPS-induced RAW264.7 cells. The protein expression of nuclear NF-κB was measured by Western blot. The results showed that the safe medication range of SMP was less than 3 mg/mL. Compared with the LPS model group, SMP (2, 1, and 0.5 mg/mL) improved the degree of cell deformation and reduced the amount of pseudopodia, and statistically reduced the secretions of cytokines in cells induced by LPS (P < 0.01) at different time points. SMP significantly inhibited the mRNA transcriptions of TNF-α, IL-6, iNOS, and COX-2 and the protein expressions of NF-κB, p-p65, and p-IκBa. In conclusion, this study preliminarily proved the protective effect of SMP on LPS-induced RAW264.7 macrophage. Its mechanism might be related to inhibition of NF-κB signal pathway and the gene expressions and secretion of cytokines.

Peroxiredoxin 5 ameliorates obesity-induced non-alcoholic fatty liver disease through the regulation of oxidative stress and AMP-activated protein kinase signaling

Non-alcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease globally. NAFLD—which can develop into liver fibrosis, nonalcoholic steatohepatosis, cirrhosis, and hepatocellular carcinoma—is defined as an excess accumulation of fat caused by abnormal lipid metabolism and excessive reactive oxygen species (ROS) generation in hepatocytes. Recently, we reported that Peroxiredoxin 5 (Prx5) plays an essential role in regulating adipogenesis and suggested the need to further investigation on the potential curative effects of Prx5 on obesity-induced fatty liver disease. In the present study, we focused on the role of Prx5 in fatty liver disease. We found that Prx5 overexpression significantly suppressed cytosolic and mitochondrial ROS generation. Additionally, Prx5 regulated the AMP-activated protein kinase pathway and lipogenic gene (sterol regulatory element binding protein-1 and FAS) expression; it also inhibited lipid accumulation, resulting in the amelioration of free fatty acid-induced hepatic steatosis. Silence of Prx5 triggered de novo lipogenesis and abnormal lipid accumulation in HepG2 cells. Concordantly, Prx5 knockout mice exhibited a high susceptibility to obesity-induced hepatic steatosis. Liver sections of Prx5-deletion mice fed on a high-fat diet displayed Oil Red O-stained dots and small leaky shapes due to immoderate fat deposition. Collectively, our findings suggest that Prx5 functions as a protective regulator in fatty liver disease and that it may be a valuable therapeutic target for the management of obesity-related metabolic diseases.

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Prx5 decreased the FFA-induced intracellular and mitochondrial ROS generation.

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Prx5 improved hepatic steatosis via regulation of AMP-activated protein kinase.

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Knockout of Prx5 aggravated obesity related fatty liver disease.

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Prx5 has a crucial role in hepatic lipid metabolism.

Socioeconomic Deprivation, Adverse Childhood Experiences and Medical Disorders in Adulthood: Mechanisms and Associations

Severe socioeconomic deprivation (SED) and adverse childhood experiences (ACE) are significantly associated with the development in adulthood of (i) enhanced inflammatory status and/or hypothalamic-pituitary-adrenal (HPA) axis dysfunction and (ii) neurological, neuroprogressive, inflammatory and autoimmune diseases. The mechanisms by which these associations take place are detailed. The two sets of consequences are themselves strongly associated, with the first set likely contributing to the second. Mechanisms enabling bidirectional communication between the immune system and the brain are described, including complex signalling pathways facilitated by factors at the level of immune cells. Also detailed are mechanisms underpinning the association between SED, ACE and the genesis of peripheral inflammation, including epigenetic changes to immune system-related gene expression. The duration and magnitude of inflammatory responses can be influenced by genetic factors, including single nucleotide polymorphisms, and by epigenetic factors, whereby pro-inflammatory cytokines, reactive oxygen species, reactive nitrogen species and nuclear factor-κB affect gene DNA methylation and histone acetylation and also induce several microRNAs including miR-155, miR-181b-1 and miR-146a. Adult HPA axis activity is regulated by (i) genetic factors, such as glucocorticoid receptor polymorphisms; (ii) epigenetic factors affecting glucocorticoid receptor function or expression, including the methylation status of alternative promoter regions of NR3C1 and the methylation of FKBP5 and HSD11β2; (iii) chronic inflammation and chronic nitrosative and oxidative stress. Finally, it is shown how severe psychological stress adversely affects mitochondrial structure and functioning and is associated with changes in brain mitochondrial DNA copy number and transcription; mitochondria can act as couriers of childhood stress into adulthood.

Decursinol angelate ameliorates 12-O-tetradecanoyl phorbol-13-acetate (TPA) -induced NF-κB activation on mice ears by inhibiting exaggerated inflammatory cell infiltration, oxidative stress and pro-inflammatory cytokine production

Decursinol angelate (DA) is a pyranocoumarin purified from the roots of Angelica gigas. Here, we synthesized DA and determined its anti-inflammatory potential on TPA-induced mice ear inflammation. First, we evaluated the non-toxic behaviour of DA on HaCaT cells. Additionally, we observed the free radical scavenging potential of DA at 60 μM to be 50%. This finding was further supported by nitric oxide assay, malondialdehyde assay, H2DCFDA staining and western blotting analysis of antioxidant enzymes. DA also suppressed the activation and polarization of macrophage phagocytic activity on RAW 264.7 cells. We further evaluated the expression of ICAM-1, MCP-1, MIP-2 and MIP-1β on in-vivo model system. Consequently, DA significantly reduced the production of NF-κB and COX-2 induced proinflammatory cytokine levels on TPA induced ear edema. Inhibition of MAPK and transcriptional factor NF-κB was also validated by western blotting analysis of p-ERK, p-p38, IKKα, IKKγ, IκBα, NF-κB-p65. Immunohistochemistry and immunofluorescence staining of NFκB-p65, TNF-α and IL-1β were also performed to support the findings. Conclusively, these results suggest that topical administration of DA significantly inhibited the expression of pro-inflammatory cytokines by blocking the canonical NF-κB and MAPK pathway. Therefore, we suggest DA as a potent therapeutic compound against skin inflammation related diseases.

DNA methylation is involved in pro-inflammatory cytokines expression in T-2 toxin-induced liver injury

Currently, T-2 toxin has been reported to cause liver toxicity with the effects of oxidative stress and inflammation; however, the underlying mechanism of T-2 toxin-induced liver injury is not fully understood. Increasing lines of evidence show that DNA methylation affects the expression of inflammatory cytokine, and plays a crucial role in autoimmune diseases. Nevertheless, the potential role of DNA methylation in the hepatotoxicity of T-2 toxin has not been explored. In this study, female Wistar rats were given a single dose of T-2 toxin at 2 mg/kg b.w. and were sacrificed at 1, 3 and 7 days post-exposure. In vitro, a normal rat liver cell line (BRL) was exposed to different concentrations of T-2 toxin. Histopathological analysis was used to investigate damage to the liver, which was detected at the molecular level by RT-PCR, Western blot and immunohistochemical assays, methylation-specific PCR (MSP), bisulfite sequencing (BSP), and flow cytometry. The results showed that T-2 toxin significantly increased the levels of DNA methyltransferases (DNMT1, DNMT3A), which were mainly concentrated at the site of liver injury. The 5-methylcytosine (5-mC) level of genomic DNA was also raised in T-2 toxin-treated rat livers. The expression of inflammatory cytokines (IL-6, IL-1β, IL-11, IL-1α, and TNF-α) increased both in vivo and in vitro under T-2 toxin treatment. Notably, DNA demethylation directly increased the expression of cytokines IL-11, IL-6, IL-α, and TNF-α under T-2 toxin exposure. DNA methylation inhibitors combined with T-2 toxin directly or indirectly induced the production of inflammatory cytokines and aggravate cell apoptosis. Our study uncovered for the first time that DNA methylation is related to the expression of inflammatory cytokines in T-2 toxin-induced liver injury. These findings suggested that DNA methylation is a potential mechanism of T-2 toxin-induced hepatotoxicity.

Varroa destructor parasitism has a greater effect on proteome changes than the deformed wing virus and activates TGF-β signaling pathways

Honeybee workers undergo metamorphosis in capped cells for approximately 13 days before adult emergence. During the same period, Varroa mites prick the defenseless host many times. We sought to identify proteome differences between emerging Varroa-parasitized and parasite-free honeybees showing the presence or absence of clinical signs of deformed wing virus (DWV) in the capped cells. A label-free proteomic analysis utilizing nanoLC coupled with an Orbitrap Fusion Tribrid mass spectrometer provided a quantitative comparison of 2316 protein hits. Redundancy analysis (RDA) showed that the combination of Varroa parasitism and DWV clinical signs caused proteome changes that occurred in the same direction as those of Varroa alone and were approximately two-fold higher. Furthermore, proteome changes associated with DWV signs alone were positioned above Varroa in the RDA. Multiple markers indicate that Varroa activates TGF-β-induced pathways to suppress wound healing and the immune response and that the collective action of stressors intensifies these effects. Furthermore, we indicate JAK/STAT hyperactivation, p53-BCL-6 feedback loop disruption, Wnt pathway activation, Wnt/Hippo crosstalk disruption, and NF-κB and JAK/STAT signaling conflict in the Varroa–honeybee–DWV interaction. These results illustrate the higher effect of Varroa than of DWV at the time of emergence. Markers for future research are provided.

Long Noncoding RNA Expression Profile in BV2 Microglial Cells Exposed to Lipopolysaccharide

Neuropathic pain, which is one of the most common forms of chronic pain, seriously increases healthcare costs and impairs patients' quality of life with an incidence of 7–10% worldwide. Microglia cell activation plays a key role in the progression of neuropathic pain. Better understanding of novel molecules modulating microglia cell activation and these underlying functions will extremely benefit the exploration of new treatment. Recent studies suggested long noncoding RNAs may be involved in neuropathic pain. However, its underlying functions and mechanisms in microglia cell activation remain unclear. To identify the differentially expressed lncRNAs and predict their functions in the progression of microglia cell activation, GSE103156 was analyzed using integrated bioinformatics methods. The expression levels of selected lncRNAs and mRNAs were determined by real-time PCR. In the present study, a total of 56 lncRNAs and 298 mRNAs were significantly differentially expressed. The differentially expressed mRNAs were mainly enriched in NF-kappa B signaling pathway, TNF signaling pathway, Toll-like receptor signaling pathway, and NOD-like receptor signaling pathway. The top 10 hub genes were Tnf, Il6, Stat1, Cxcl10, Il1b, Tlr2, Irf1, Ccl2, Irf7, and Ccl5 in the PPI network. Our results showed that Gm8989, Gm8979, and AV051173 may be involved in the progression of microglia cell activation. Taken together, our findings suggest that lots of lncRNAs may be involved in BV2 microglia cell activation in vitro. The findings may provide relevant information for the development of promising targets for the microglial cells activation of neuropathic pain in vivo in the future.

The Toxoplasma effector TEEGR promotes parasite persistence by modulating NF-κB signalling via EZH2

The protozoan parasite Toxoplasma gondii has co-evolved with its homeothermic hosts (humans included) strategies that drive its quasi-asymptomatic persistence in hosts, hence optimizing the chance of transmission to new hosts. Persistence, which starts with a small subset of parasites that escape host immune killing and colonize the so-called immune privileged tissues where they differentiate into a low replicating stage, is driven by the interleukin 12 (IL-12)-interferon-γ (IFN-γ) axis. Recent characterization of a family of Toxoplasma effectors that are delivered into the host cell, in which they rewire the host cell gene expression, has allowed the identification of regulators of the IL-12-IFN-γ axis, including repressors. We now report on the dense granule-resident effector, called TEEGR (Toxoplasma E2F4-associated EZH2-inducing gene regulator) that counteracts the nuclear factor-κB (NF-κB) signalling pathway. Once exported into the host cell, TEEGR ends up in the nucleus where it not only complexes with the E2F3 and E2F4 host transcription factors to induce gene expression, but also promotes shaping of a non-permissive chromatin through its capacity to switch on EZH2. Remarkably, EZH2 fosters the epigenetic silencing of a subset of NF-κB-regulated cytokines, thereby strongly contributing to the host immune equilibrium that influences the host immune response and promotes parasite persistence in mice.

Considering Abundance, Affinity, and Binding Site Availability in the NF-κB Target Selection Puzzle

The NF-κB transcription regulation system governs a diverse set of responses to various cytokine stimuli. With tools from in vitro biochemical characterizations, to omics-based whole genome investigations, great strides have been made in understanding how NF-κB transcription factors control the expression of specific sets of genes. Nonetheless, these efforts have also revealed a very large number of potential binding sites for NF-κB in the human genome, and a puzzle emerges when trying to explain how NF-κB selects from these many binding sites to direct cell-type- and stimulus-specific gene expression patterns. In this review, we surmise that target gene transcription can broadly be thought of as a function of the nuclear abundance of the various NF-κB dimers, the affinity of NF-κB dimers for the regulatory sequence and the availability of this regulatory site. We use this framework to place quantitative information that has been gathered about the NF-κB transcription regulation system into context and thus consider questions it answers, and questions it raises. We end with a brief discussion of some of the future prospects that new approaches could bring to our understanding of how NF-κB transcription factors orchestrate diverse responses in different biological contexts.

4'‑O‑Methylalpinumisoflavone inhibits the activation of monocytes/macrophages to an immunostimulatory phenotype induced by 27‑hydroxycholesterol

The epidemiological, animal and cell effects of plant metabolites suggest versatile health benefits of flavonoids. However, whether flavonoids affect the deleterious biological activity of oxygenated cholesterol molecules remains to be elucidated. The present study investigated the effects of 4'‑O‑methylalpinumisoflavone (mAI) isolated from Maclura tricuspidata (Cudrania tricuspidata) on the 27‑hydroxycholesterol (27OHChol)‑induced activation of monocytes/macrophages using human THP‑1 cells. mAI dose‑dependently impaired the expression of C‑C motif chemokine ligand (CCL)2 chemokine and the migration of monocytic cells enhanced by 27OHChol. mAI downregulated the surface and cellular levels of CD14 and inhibited the release of soluble CD14. This isoflavone significantly weakened the lipopolysaccharide responses that were enhanced in the presence of 27OHChol, and inhibited the transcription and secretion of the active gene product of matrix metalloproteinase‑9. mAI also suppressed the expression of C‑C motif chemokine receptor 5 ligands, including CL3 and CCL4, and M1‑phenotype markers induced by 27OHChol. Furthermore, mAI impaired phosphorylation of the nuclear factor‑κB p65 subunit without affecting the phosphorylation of Akt. These results indicate that mAI inhibits the activation of monocytes/macrophages to the immunostimulatory phenotype in a milieu rich in 27OHChol, suggesting potential benefits of the flavonoid for the treatment of diseases in which the pathogenesis is linked to 27OHChol‑induced inflammatory responses.

Gene activation precedes DNA demethylation in response to infection in human dendritic cells

Immune response to infection is accompanied by active demethylation of thousands of CpG sites. Yet, the causal relationship between changes in DNA methylation and gene expression during infection remains to be elucidated. Here, we investigated the role of DNA methylation in the regulation of innate immune responses to bacterial infections. We found that virtually all changes in gene expression in response to infection occur prior to detectable alterations in the methylome. We also found that the binding of most infection-induced transcription factors precedes loss of methylation. Collectively, our results show that changes in methylation are a downstream consequence of transcription factor binding, and not essential for the establishment of the core regulatory program engaged upon infection.

DNA methylation is considered to be a relatively stable epigenetic mark. However, a growing body of evidence indicates that DNA methylation levels can change rapidly; for example, in innate immune cells facing an infectious agent. Nevertheless, the causal relationship between changes in DNA methylation and gene expression during infection remains to be elucidated. Here, we generated time-course data on DNA methylation, gene expression, and chromatin accessibility patterns during infection of human dendritic cells with Mycobacterium tuberculosis. We found that the immune response to infection is accompanied by active demethylation of thousands of CpG sites overlapping distal enhancer elements. However, virtually all changes in gene expression in response to infection occur before detectable changes in DNA methylation, indicating that the observed losses in methylation are a downstream consequence of transcriptional activation. Footprinting analysis revealed that immune-related transcription factors (TFs), such as NF-κB/Rel, are recruited to enhancer elements before the observed losses in methylation, suggesting that DNA demethylation is mediated by TF binding to cis-acting elements. Collectively, our results show that DNA demethylation plays a limited role to the establishment of the core regulatory program engaged upon infection.

A diet enriched with curcumin promotes resilience to chronic social defeat stress

Chronic exposure to stress is a well-known risk factor for the development of mood and anxiety disorders. Promoting resilience to stress may prevent the development of these disorders, but resilience-enhancing compounds are not yet clinically available. One compound that has shown promise in the clinical setting is curcumin, a polyphenol compound found in the rhizome of the turmeric plant (Curcuma longa) with known anti-inflammatory and antidepressant properties. Here, we tested the efficacy of 1.5% dietary curcumin at promoting resilience to chronic social defeat stress (CSDS) in 129/SvEv mice, a strain that we show is highly susceptible to this type of stress. We found that administration of curcumin during CSDS produced a 4.5-fold increase in stress resilience, as measured by the social interaction test. Although the overall effects of curcumin were striking, we identified two distinct responses to curcumin. While 64% of defeated mice on curcumin were resilient (responders), the remaining 36% of mice were susceptible to the effects of stress (non-responders). Interestingly, responders released less corticosterone following acute restraint stress and had lower levels of peripheral IL-6 than nonresponders, implicating a role for the NF-κB pathway in treatment response. Importantly, curcumin also prevented anxiety-like behavior in both responders and non-responders in the elevated-plus maze and open field test. Collectively, our findings provide the first preclinical evidence that curcumin promotes resilience to CSDS and suggest that curcumin may prevent the emergence of a range of anxiety-like symptoms when given to individuals during exposure to chronic social stress.

Raman spectroscopy reveals LPS-induced changes of biomolecular composition in monocytic THP-1 cells in a label-free manner

The human innate immune system is able to recognize pathogen-associated molecular patterns like lipopolysaccharides (LPS) leading to the activation of signal cascades and the release of different cytokines. Activation of the immune cells can be assessed in different ways which are either indirect (ELISA of cytokine release), require staining protocols (flow cytometry) or lysis of the cells (mRNA analysis). Here, Raman spectroscopy as a non-destructive spectroscopic method is presented to enable direct and label-free monitoring of changes in cellular metabolism, biomolecular composition as well as morphology. Exemplarily, the potential of Raman spectroscopy is presented for the characterization of LPS-stimulation of monocytic THP-1 cells over a time course of 16 h. The cell culture stimulation model is characterized using gene transcription and expression of the two cytokines TNFα and IL-1β. After 1 h, 3 h, 8 h and 16 h specific Raman spectroscopic fingerprints are generated which encode cell activation pattern after TLR4 stimulation. Most prevalent changes in the spectra occur after 8 h, but slight differences are already detectable after 1 h. Spatially highly resolved Raman scans are used to generate false-color Raman images which provide spatial information of the biochemical state of the cells and changes over time. One of the most significant observed differences is an increase in Raman signal from DNA/RNA content in LPS-stimulated cells when compared to unstimulated cells. The systematic assignment of Raman spectroscopic profiles of LPS-activated cells to cellular activation assessed by cytokine gene transcription and expression opens new ways for label-free and direct immunological studies of specific pathogen recognizing receptors and their downstream signaling pathways.

GSH-C4 Acts as Anti-inflammatory Drug in Different Models of Canonical and Cell Autonomous Inflammation Through NFκB Inhibition

An imbalance in GSH/GSSG ratio represents a triggering event in pro-inflammatory cytokine production and inflammatory response. However, the molecular mechanism(s) through which GSH regulates macrophage and cell autonomous inflammation remains not deeply understood. Here, we investigated the effects of a derivative of GSH, the N-butanoyl glutathione (GSH-C4), a cell permeable compound, on lipopolisaccharide (LPS)-stimulated murine RAW 264.7 macrophages, and human macrophages. LPS alone induces a significant production of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α and a significant decrement of GSH content. Such events were significantly abrogated by treatment with GSH-C4. Moreover, GSH-C4 was highly efficient in buffering cell autonomous inflammatory status of aged C2C12 myotubes and 3T3-L1 adipocytes by suppressing the production of pro-inflammatory cytokines. We found that inflammation was paralleled by a strong induction of the phosphorylated form of NFκB, which translocates into the nucleus; a process that was also efficiently inhibited by the treatment with GSH-C4. Overall, the evidence suggests that GSH decrement is required for efficient activation of an inflammatory condition and, at the same time, GSH-C4 can be envisaged as a good candidate to abrogate such process, expanding the anti-inflammatory role of this molecule in chronic inflammatory states.

Single-molecule dynamics and genome-wide transcriptomics reveal that NF-kB (p65)-DNA binding times can be decoupled from transcriptional activation

Transcription factors (TFs) regulate gene expression in both prokaryotes and eukaryotes by recognizing and binding to specific DNA promoter sequences. In higher eukaryotes, it remains unclear how the duration of TF binding to DNA relates to downstream transcriptional output. Here, we address this question for the transcriptional activator NF-κB (p65), by live-cell single molecule imaging of TF-DNA binding kinetics and genome-wide quantification of p65-mediated transcription. We used mutants of p65, perturbing either the DNA binding domain (DBD) or the protein-protein transactivation domain (TAD). We found that p65-DNA binding time was predominantly determined by its DBD and directly correlated with its transcriptional output as long as the TAD is intact. Surprisingly, mutation or deletion of the TAD did not modify p65-DNA binding stability, suggesting that the p65 TAD generally contributes neither to the assembly of an "enhanceosome," nor to the active removal of p65 from putative specific binding sites. However, TAD removal did reduce p65-mediated transcriptional activation, indicating that protein-protein interactions act to translate the long-lived p65-DNA binding into productive transcription.

Curcumin Analogs Reduce Stress and Inflammation Indices in Experimental Models of Diabetes

Chronic inflammation and oxidative stress lead to a multitude of adverse cellular responses in target organs of chronic diabetic complications. Curcumin, a highly investigated phytochemical, has been shown to exhibit both anti-inflammatory and antioxidant activities. However, the clinical application of curcumin has been greatly limited due to a poor pharmacokinetic profile. To overcome these limitations, we have generated analogs of curcumin to enhance bioavailability and offer a preferable pharmacokinetic profile. Here, we explored the effects of two mono-carbonyl curcumin analogs, L2H21 and L50H46, in alleviating indices of inflammation and oxidative stress in cell culture and mouse model of diabetic complications. Our results show that L2H21 and L50H46 normalize inflammatory mediators (IL-6 and TNF-α), extracellular matrix proteins (FN and COL4α1), vasoactive factors (VEGF and ET-1) and a key transcriptional coactivator (p300) in cultured human retinal microvascular endothelial cells (HRECs) and dermal-derived microvascular endothelial cells (HMVECs) challenged with high levels of glucose. These curcumin analogs also reduced glucose-induced oxidative DNA damage as evidenced by 8-OHdG labeling. We further show that treatment of streptozotocin-induced diabetic mice with curcumin analogs prevents cardiac and renal dysfunction. The preservation of target tissue function was associated with normalization of pro-inflammatory cytokines and matrix proteins. Collectively, our results show that L2H21 and L50H46 offer the anti-inflammatory and antioxidant activities as has been reported for curcumin, and may provide a clinically applicable therapeutic option for the treatment of diabetic complications.

Changes in H3K27ac following lipopolysaccharide stimulation of nasopharyngeal epithelial cells

BACKGROUND

The epithelium is the first line of defense against pathogens. Notably the epithelial cells lining the respiratory track are crucial in sensing airborne microbes and mounting an effective immune response via the expression of target genes such as cytokines and chemokines. Gene expression regulation following microbial recognition is partly regulated by chromatin re-organization and has been described in immune cells but data from epithelial cells is not as detailed. Here, we report genome-wide changes of the H3K27ac mark, characteristic of activated enhancers and promoters, after stimulation of nasopharyngeal epithelial cells with the bacterial endotoxin Lipopolysaccharide (LPS).

RESULTS

In this study, we have identified 626 regions where the H3K27ac mark showed reproducible increase following LPS induction in epithelial cells. This indicated that sensing of LPS led to opening of the chromatin in our system. Moreover, this phenomenon seemed to happen extensively at enhancers regions and we could observe instances of Super-enhancer formation. As expected, LPS-increased H3K27ac regions were found in the vicinity of genes relevant for LPS response and these changes correlated with up-regulation of their expression. In addition, we found the induction of H3K27ac mark to overlap with the binding of one of the NF-kB members and key regulator of the innate immune response, RELA, following LPS sensing. Indeed, inhibiting the NF-kB pathway abolished the deposition of H3K27ac at the TNF locus, a target of RELA, suggesting that these two phenomena are associated.

CONCLUSIONS

Enhancers' selection and activation following microbial or inflammatory stimuli has been described previously and shown to be mediated via the NF-kB pathway. Here, we demonstrate that this is also likely to occur in the case of LPS-sensing by nasopharyngeal epithelial cells as well. In addition to validating previous findings, we generated a valuable data set relevant to the host immune response to epithelial cell colonizing or infecting pathogens.

Mechanisms of NF-κB p65 and strategies for therapeutic manipulation

The transcription factor NF-κB is a critical regulator of immune and inflammatory responses. In mammals, the NF-κB/Rel family comprises five members: p50, p52, p65 (Rel-A), c-Rel, and Rel-B proteins, which form homo- or heterodimers and remain as an inactive complex with the inhibitory molecules called IκB proteins in resting cells. Two distinct NF-κB signaling pathways have been described: 1) the canonical pathway primarily activated by pathogens and inflammatory mediators, and 2) the noncanonical pathway mostly activated by developmental cues. The most abundant form of NF-κB activated by pathologic stimuli via the canonical pathway is the p65:p50 heterodimer. Disproportionate increase in activated p65 and subsequent transactivation of effector molecules is integral to the pathogenesis of many chronic diseases such as the rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, and even neurodegenerative pathologies. Hence, the NF-κB p65 signaling pathway has been a pivotal point for intense drug discovery and development. This review begins with an overview of p65-mediated signaling followed by discussion of strategies that directly target NF-κB p65 in the context of chronic inflammation.

Tumor Necrosis Factor Alpha Induces Reactivation of Human Cytomegalovirus Independently of Myeloid Cell Differentiation following Posttranscriptional Establishment of Latency

HCMV is an important human pathogen that establishes lifelong latent infection in myeloid progenitor cells and reactivates frequently to cause significant disease in immunocompromised people. Our observation that viral gene expression is first turned on and then turned off to establish latency suggests that there is a host defense, which may be myeloid cell specific, responsible for transcriptional silencing of viral gene expression. Our observation that TNF-α induces reactivation independently of differentiation provides insight into molecular mechanisms that control reactivation.

We used the Kasumi-3 model to study human cytomegalovirus (HCMV) latency and reactivation in myeloid progenitor cells. Kasumi-3 cells were infected with HCMV strain TB40/Ewt-GFP, flow sorted for green fluorescent protein-positive (GFP⁺) cells, and cultured for various times to monitor establishment of latency, as judged by repression of viral gene expression (RNA/DNA ratio) and loss of virus production. We found that, in the vast majority of cells, latency was established posttranscriptionally in the GFP⁺ infected cells: transcription was initially turned on and then turned off. We also found that some of the GFP⁻ cells were infected, suggesting that latency might be established in these cells at the outset of infection. We were not able to test this hypothesis because some GFP⁻ cells expressed lytic genes and thus it was not possible to separate them from GFP⁻ quiescent cells. In addition, we found that the pattern of expression of lytic genes that have been associated with latency, including UL138, US28, and RNA2.7, was the same as that of other lytic genes, indicating that there was no preferential expression of these genes once latency was established. We confirmed previous studies showing that tumor necrosis factor alpha (TNF-α) induced reactivation of infectious virus, and by analyzing expression of the progenitor cell marker CD34 as well as myeloid cell differentiation markers in IE⁺ cells after treatment with TNF-α, we showed that TNF-α induced transcriptional reactivation of IE gene expression independently of differentiation. TNF-α-mediated reactivation in Kasumi-3 cells was correlated with activation of NF-κB, KAP-1, and ATM.

Reduced Neuronal Transcription of Escargot, the Drosophila Gene Encoding a Snail-Type Transcription Factor, Promotes Longevity

In recent years, several genes involved in complex neuron specification networks have been shown to control life span. However, information on these genes is scattered, and studies to discover new neuronal genes and gene cascades contributing to life span control are needed, especially because of the recognized role of the nervous system in governing homeostasis, aging, and longevity. Previously, we demonstrated that several genes that encode RNA polymerase II transcription factors and that are involved in the development of the nervous system affect life span in Drosophila melanogaster. Among other genes, escargot (esg) was demonstrated to be causally associated with an increase in the life span of male flies. Here, we present new data on the role of esg in life span control. We show that esg affects the life spans of both mated and unmated males and females to varying degrees. By analyzing the survival and locomotion of the esg mutants, we demonstrate that esg is involved in the control of aging. We show that increased longevity is caused by decreased esg transcription. In particular, we demonstrate that esg knockdown in the nervous system increased life span, directly establishing the involvement of the neuronal esg function in life span control. Our data invite attention to the mechanisms regulating the esg transcription rate, which is changed by insertions of DNA fragments of different sizes downstream of the structural part of the gene, indicating the direction of further research. Our data agree with the previously made suggestion that alterations in gene expression during development might affect adult lifespan, due to epigenetic patterns inherited in cell lineages or predetermined during the development of the structural and functional properties of the nervous system.

NOS1 mediates AP1 nuclear translocation and inflammatory response

A hallmark of the AP1 functioning is its nuclear translocation, which induces proinflammatory cytokine expression and hence the inflammatory response. After endotoxin shock AP1 transcription factor, which comprises Jun, ATF2, and Fos family of proteins, translocates into the nucleus and induces proinflammatory cytokine expression. In the current study, we found, NOS1 inhibition prevents nuclear translocation of the AP1 transcription factor subunits. Pharmacological inhibition of NOS1 impedes translocation of subunits into the nucleus, suppressing the transcription of inflammatory genes causing a diminished inflammatory response. In conclusion, the study shows the novel mechanism of NOS1- mediated AP1 nuclear translocation, which needs to be further explored.

Neonatal Colonic Inflammation Epigenetically Aggravates Epithelial Inflammatory Responses to Injury in Adult Life

BACKGROUND & AIMS

Early life adversity is considered a risk factor for the development of gastrointestinal diseases, including inflammatory bowel disease. We hypothesized that early life colonic inflammation causes susceptibility to aggravated overexpression of interleukin (IL)1β.

METHODS

We developed a 2-hit rat model in which neonatal inflammation (NI) and adult inflammation (AI) were induced by trinitrobenzene sulfonic acid.

RESULTS

Aggravated immune responses were observed in NI + AI rats, including a sustained up-regulation of IL1β and other cytokines. In parallel with exacerbated loss of inhibitor of kappa B alpha expression, NI + AI rats showed hyperacetylation of histone H4K12 and increased V-Rel Avian Reticuloendotheliosis Viral Oncogene Homolog A binding on the IL1B promoter, accompanied by high levels of norepinephrine/epinephrine. Propranolol, a β-blocker, markedly ameliorated the inflammatory response and IL1β overexpression by mitigating against epigenetic modifications. Adrenalectomy abrogated NI-induced disease susceptibility whereas yohimbine sensitized the epithelium for exacerbated immune response. The macrophages of NI rats produced more IL1β than controls after exposure to lipopolysaccharide (LPS), suggesting hypersensitization; incubation with LPS plus Foradil (Sigma, St. Louis, MO), a β2-agonist, induced a greater IL1β expression than LPS alone. Epinephrine and Foradil also exacerbated LPS-induced IL1β activation in human THP-1-derived macrophages, by increasing acetylated H4K12, and these increases were abrogated by propranolol.

CONCLUSIONS

NI sensitizes the colon epithelium for exacerbated IL1β activation by increasing stress hormones that induce histone hyperacetylation, allowing greater access of nuclear factor-κB to the IL1B promoter and rendering the host susceptible to aggravated immune responses. Our findings suggest that β blockers have a therapeutic potential for inflammatory bowel disease susceptibility and establish a novel paradigm whereby NI induces epigenetic susceptibility to inflammatory bowel disease.

Immunosuppressive effects of hydroxychloroquine and artemisinin combination therapy via the nuclear factor-κB signaling pathway in lupus nephritis mice

Lupus nephritis (LN) is one of the most common and severe manifestations of systemic lupus erythematosus, leading to permanent renal damage and chronic kidney disease. Hydroxychloroquine (HCQ) serves a protective role against lupus-associated clinical manifestations and medical complications; however, it results in numerous adverse reactions, limiting its long-term use. The aim of the present study was to investigate the combined effect of HCQ and artemisinin (ART) on LN, and to elucidate the underlying mechanisms. An in vivo LN mouse model was prepared, and the animals were administered prednisone (PDS; serving as a positive control), high-dose HCQ (H-HCQ) or low-dose HCQ combined with ART (L-HCQ + ART) once daily for 8 weeks. The body weight, serum biochemical parameters, immune and inflammatory indicators, renal and spleen histological alterations, and mRNA expression levels of Kruppel-like factor 15 (KLF15) and nuclear factor-κB (NF-κB) were analyzed. It was observed that L-HCQ + ART and H-HCQ ameliorated the LN-induced body weight decrease, and significantly decreased the levels of anti-double stranded DNA, antinuclear antibodies, immunoglobulin G, interferon γ, tumor necrosis factor-α and transforming growth factor-β1, as well as improved the kidney and spleen pathology, when compared with the model group. In addition, L-HCQ + ART and H-HCQ treatments induced KLF15 upregulation and NF-κB downregulation. These results indicated that treatment with L-HCQ + ART exerted renoprotective effects by regulating the expression levels of cytokines, KLF15 and NF-κB. This combination treatment may have a similar immunosuppressive effect as PDS and H-HCQ, and may be a promising alternative for LN treatment.

IKKβ Activation in the Fetal Lung Mesenchyme Alters Lung Vascular Development but Not Airway Morphogenesis

In the immature lung, inflammation and injury disrupt the epithelial-mesenchymal interactions required for normal development. Innate immune signaling and NF-κB activation disrupt the normal expression of multiple mesenchymal genes that play a key role in airway branching and alveolar formation. To test the role of the NF-κB pathway specifically in lung mesenchyme, we utilized the mesenchymal Twist2-Cre to drive expression of a constitutively active inhibitor of NF-κB kinase subunit β (IKKβca) mutant in developing mice. Embryonic Twist2-IKKβca mice were generated in expected numbers and appeared grossly normal. Airway branching also appeared normal in Twist2-IKKβca embryos, with airway morphometry, elastin staining, and saccular branching similar to those in control littermates. While Twist2-IKKβca lungs did not contain increased levels of Il1b, we did measure an increased expression of the chemokine-encoding gene Ccl2. Twist2-IKKβca lungs had increased staining for the vascular marker platelet endothelial cell adhesion molecule 1. In addition, type I alveolar epithelial differentiation appeared to be diminished in Twist2-IKKβca lungs. The normal airway branching and lack of Il1b expression may have been due to the inability of the Twist2-IKKβca transgene to induce inflammasome activity. While Twist2-IKKβca lungs had an increased number of macrophages, inflammasome expression remained restricted to macrophages without evidence of spontaneous inflammasome activity. These results emphasize the importance of cellular niche in considering how inflammatory signaling influences fetal lung development.

Thrombin Induces CCL2 Expression in Human Lung Fibroblasts via p300 Mediated Histone Acetylation and NF-KappaB Activation

Thrombin has been shown to play a key role in lung diseases such as pulmonary fibrosis via the induction of fibrotic cytokine- chemokine (CC motif) ligand-2 (CCL2) expression. We previously reported that transcription factor nuclear factor-κB (NF-κB) is responsible for thrombin-induced CCL2 expression in human lung fibroblasts (HLFs). Here, we extended our study to investigate the epigenetic regulation mechanism for thrombin-induced CCL2 expression in HLFs. HLFs were cultured in F-12 medium. CCL2 protein and mRNA levels were detected by ELISA and quantitative real-time PCR, respectively. Histone, histone acetyltransferases, and NF-κB binding to CCL2 promoter were detected by ChIP assay. NF-κB activation was detected by Western blotting. We revealed that increased binding of histone acetyltransferase p300 and acetylated histone H3 and H4 to CCL2 promoter are responsible for thrombin induced CCL2 expression in HLF cells. In addition, p300 inhibition attenuates both thrombin induced-CCL2 expression and histone H3 and H4 acetylation in HLFs, suggesting that p300 is involved in thrombin-induced CCL2 expression via hyperacetylating histone H3 and H4. Our data further showed that p300 also regulates CCL2 expression via interaction with NF-κB p65, as depletion of p300 inhibits both NF-κB p65 activation and its binding to CCL2 promoter. The findings strongly suggest that epigenetic dysregulation and the interaction between histone acetyltransferase and transcription factor may be responsible for thrombin induced-CCL2 expression in HLFs. Increased understanding of the epigenetic mechanisms of CCL2 regulation may provide opportunities for identifying novel molecular targets for therapeutic purposes. J. Cell. Biochem. 118: 4012-4019, 2017. © 2017 Wiley Periodicals, Inc.

The archaic roles of the lamprey NF-κB (lj-NF-κB) in innate immune responses

The nuclear factor-kappa B (NF-κB) is a pleiotropic transcription factor regulating the expression of genes involved in various biological processes including the immune response and inflammation. Lamprey is regarded as a key species to provide meaningful clues for understanding the evolution of immune system; nevertheless, no information about lamprey NF-κB is reported. Thus, we have characterized a NF-κB homolog in lamprey (lj-NF-κB) for the deeper understanding of the role it played in lamprey immune system. The sequence and 3D structure analyses demonstrate that lj-NF-κB contained a Rel homology domain (RHD) and seven ankyrin repeats domains (ANKs), which would exhibit functional similarities to NF-κB superfamily proteins. This hypothesis was further proved by experiments. We found that the RHD of lj-NF-κB could interact with a mammalian κB response element, translocate to the nucleus to modulate gene (IL-6, IL-1β and TNF-α) expression, and the nuclear localization signals (NLS) was essential for the nuclear translocation. Furthermore, the ANKs of lj-NF-κB are the inhibition signal for the RHD of lj-NF-κB. The present results allow us to surmise that the lj-NF-κB should play a key role in immune response of lamprey, and the function of NF-κB has been maintained during evolution.

The NF-κB Family of Transcription Factors and Its Role in Thyroid Physiology

The nuclear factor (NF)-κB signaling pathway controls a variety of important biological functions, including immune and inflammatory responses, differentiation, cell growth, tumorigenesis, and apoptosis. Two distinct pathways of NF-κB activation are known. The classical, canonical pathway is found virtually in all mammalian cells and NF-κB activation is mediated by the IKK complex, consisting of the IKK1/IKKα and IKK2/IKKβ catalytic kinase subunits and the NF-κB essential modulator (NEMO)/IKKγ protein. The NF-κB-driven transcriptional responses to many different stimuli have been widely characterized in the pathophysiology of the mammalian immune system, mainly because this transcription factor regulates the expression of cytokines, growth factors, and effector enzymes in response to ligation of cellular receptors involved in immunity and inflammation. However, an impressive literature produced in the last two decades shows that NF-κB signaling plays an important role also outside of the immune system, performing different roles and functions depending on the type of tissue and organ. In thyroid, NF-κB signaling is crucial for thyrocytes survival and expression of critical thyroid markers, including Nis, Ttf1, Pax8, Tpo, and thyroglobulin, making this transcription factor essential for maintenance of normal thyroid function.

Shared genetic variants suggest common pathways in allergy and autoimmune diseases

BACKGROUND

The relationship between allergy and autoimmune disorders is complex and poorly understood.

OBJECTIVE

We sought to investigate commonalities in genetic loci and pathways between allergy and autoimmune diseases to elucidate shared disease mechanisms.

METHODS

We meta-analyzed 2 genome-wide association studies on self-reported allergy and sensitization comprising a total of 62,330 subjects. These results were used to calculate enrichment for single nucleotide polymorphisms (SNPs) previously associated with autoimmune diseases. Furthermore, we probed for enrichment within genetic pathways and of transcription factor binding sites and characterized commonalities in variant burden on tissue-specific regulatory sites by calculating the enrichment of allergy SNPs falling in gene regulatory regions in various cells using Encode Roadmap DNase-hypersensitive site data. Finally, we compared the allergy data with those of all known diseases.

RESULTS

Among 290 loci previously associated with 16 autoimmune diseases, we found a significant enrichment of loci also associated with allergy (P = 1.4e-17) encompassing 29 loci at a false discovery rate of less than 0.05. Such enrichment seemed to be a general characteristic for autoimmune diseases. Among the common loci, 48% had the same direction of effect for allergy and autoimmune diseases. Additionally, we observed an enrichment of allergy SNPs falling within immune pathways and regions of chromatin accessible in immune cells that was also represented in patients with autoimmune diseases but not those with other diseases.

CONCLUSION

We identified shared susceptibility loci and commonalities in pathways between allergy and autoimmune diseases, suggesting shared disease mechanisms. Further studies of these shared genetic mechanisms might help in understanding the complex relationship between these diseases, including the parallel increase in disease prevalence.

The tumor suppressor phosphatase and tensin homolog protein (PTEN) is negatively regulated by NF-κb p50 homodimers and involves histone 3 methylation/deacetylation in UROtsa cells chronically exposed to monomethylarsonous acid

UROtsa cells have been accepted as a model to study carcinogenicity mechanisms of arsenic-associated human bladder cancer. In vitro continuous exposure to monomethylarsonous acid (MMA^III), leads UROtsa cells to commit to malignant transformation. In this process, NF-κβ-associated inflammatory response seems to play an important role since this transcription factor activates some minutes after cells are exposed in vitro to MMA^III and keeps activated during the cellular malignant transformation. It is known that a slight decrease in the protein phosphatase and tensin homologue (PTEN) gene expression is enough for some cells to become malignantly transformed. Interestingly, this tumor suppressor has been proven to be negatively regulated by NF-κβ through binding to its gene promoter. Based on these observations we propose that NF-κβ may be involved in arsenic associated carcinogenesis through the negative regulation of PTEN gene expression. Changes in PTEN expression and the binding of p50 NF-κβ subunit to PTEN promoter were evaluated in UROtsa cells exposed for 4, 12, 20, or 24 wk to 50nM MMA^III. Results showed that MMA^III induced a significant decrease in PTEN expression around 20 wk exposure to MMA^III,which correlated with increased binding of p50 subunit to the PTEN promoter. Consistent with these results, ChIP assays also showed a significant decrease in H3 acetylation (H3ac) but an increase in the repression marks H3k9me3 and H327me3 in PTEN promoter when compared with not treated cells. These results suggest that the activation of NF-κβ by MMA^III may participate in UROtsa cells malignant transformation through the negative regulation of PTEN expression involving p50 homodimers-mediated chromatin remodeling around the PTEN promoter.

Transcriptional control of microglia phenotypes in health and disease

Microglia are the main resident macrophage population of the CNS and perform numerous functions required for CNS development, homeostasis, immunity, and repair. Many lines of evidence also indicate that dysregulation of microglia contributes to the pathogenesis of neurodegenerative and behavioral diseases. These observations provide a compelling argument to more clearly define the mechanisms that control microglia identity and function in health and disease. In this Review, we present a conceptual framework for how different classes of transcription factors interact to select and activate regulatory elements that control microglia development and their responses to internal and external signals. We then describe functions of specific transcription factors in normal and pathological contexts and conclude with a consideration of open questions to be addressed in the future.

Protective effects of tenuigenin on Staphylococcus aureus-induced pneumonia in mice

Pneumonia is the leading cause of death in infants and young children. Staphylococcus aureus (S.aureus) is one of the most important bacteria that leads to pneumonia. Tenuigenin (TGN), a major active component isolated from the root of the Chinese herb Polygala tenuifolia, has been known to have anti-inflammatory effect. In this study, we aimed to investigate the protective effects of TGN on S.aureus-induced pneumonia in mice. The results showed that TGN significantly attenuated S.aureus-induced lung histopathological changes. TGN also inhibited lung wet/dry (W/D) ratio, and inflammatory cytokines TNF-α and IL-1β production. Furthermore, S.aureus-induced NF-κB activation was significantly inhibited by the treatment of TGN. In conclusion, the results of this study showed that TGN protected against S.aureus-induced pneumonia by inhibiting NF-κB activation. TGN might be a potential agent in the treatment of pneumonia induced by S.aureus.