NF-IL6 and NF-κB in Cytokine Gene Regulation

Synergistic effects of punicic acid and alpha lipoic acid ameliorate inflammatory and metabolic genes expression in C2C12 myoblast cells under oxidative stress condition

Inflammation is a reaction of the immune system to infection and injury; in fact, it positioned at the center of metabolic disorders, particularly obesity, type 2 diabetes, and cardiovascular diseases. Thus play a major role not only in their development, but also exerts as a crucial linking factor among those diseases. In this regard, one of the strategies for tackling this problem is application of antioxidants to treat such diseases. The present study was performed to evaluate the synergistic effects of punicic acid (PUA) and alpha-lipoic acid (ALA) as antioxidants and radical scavenging reagents on the expression of some inflammatory and metabolism-related genes under oxidative stress in the muscle cells. The experimental treatments consisted of a range of 20, 40, 80, 160, and 320 µM of PUA, and 5, 25, 50, 100, and 200 µM of ALA with a 200 µM concentration of H2 O2 as an oxidative stress inducer. Accordingly, fatty acid treatments were applied for 24 h, and H2 O2 was treated for 1 h. Our results indicated that the simultaneous treatment of PUA and ALA at optimal concentrations (80 and 50 µM, respectively) decreased the expression of inflammation genes and increased the expression of regulatory genes (Pparγ, Pgc-1α) related to metabolism (p < .05). Unexpectedly, H2 O2 treatment increased the Fndc5 expression (p < .05). Maximal upregulation of Pparγ, Pgc-1α were obtained when fatty acids combination (PUA and ALA) were used in the culture of H2 O2 treated cells (p < .05). Therefore, our findings suggest that the simultaneous use of PUA and ALA fatty acids could reduce oxidative stress, and the expression of inflammatory genes, thereby improving the cell metabolism.

Effects of polyphenols and their metabolites on age-related diseases

Aging contributes to the progressive loss of cellular biological functions and increases the risk of age-related diseases. Cardiovascular diseases, some neurological disorders and cancers are generally classified as age-related diseases that affect the lifespan of individuals. These diseases result from the accumulation of cellular damage and reduced activity of protective stress response pathways, which can lead to inflammation and oxidative stress, which play a key role in the aging process. There is now increasing interest in the therapeutic effects of edible plants for the prevention of various diseases, including those associated with aging. It has become clear that the beneficial effects of these foods are due, at least in part, to the high concentration of bioactive phenolic compounds with low side effects. Antioxidants are the most abundant, and their high consumption in the Mediterranean diet has been associated with slower ageing in humans. Extensive human dietary intervention studies strongly suggest that polyphenol supplementation protects against the development of degenerative diseases, especially in the elderly. In this review, we present data on the biological effects of plant polyphenols in the context of their relevance to human health, ageing and the prevention of age-related diseases.

Unsaturated oxidated fatty acid 12(S)-HETE attenuates TNF-α expression in TNF-α/IFN-γ-stimulated human keratinocytes

Chronic skin inflammatory diseases are associated with abnormal immune responses characterized by skin barrier dysfunction. Keratinocytes participate in immune homeostasis regulated by immune cells. Immune homeostasis dysfunction contributes to the pathogenesis of skin diseases mediated by pro-inflammatory cytokines and chemokines, such as tumor necrosis factor (TNF)-α, which are produced by activated keratinocytes. 12(S)-Hydroxy eicosatetraenoic acid [12(S)-HETE], an arachidonic acid metabolite, has anti-inflammatory properties. However, the role of 12(S)-HETE in chronic skin inflammatory diseases has not been elucidated yet. In this study, we investigated the effect of 12(S)-HETE on TNF-α/interferon (IFN)-γ-induced pro-inflammatory cytokine and chemokine expression. Our data showed that 12(S)-HETE modulates TNF-α mRNA and protein expression in TNF-α-/IFN-γ-treated human keratinocytes. Molecular docking analyses demonstrated that 12(S)-HETE bound to extracellular signal-regulated kinase (ERK)1/2, thus preventing ERK activation and downregulating phosphorylated ERK expression. We also demonstrated that 12(S)-HETE treatment inhibited IκB and ERK phosphorylation and nuclear factor (NF)-κB, p65/p50, and CCAAT/enhancerbindingproteinβ (C/EBPβ) translocation. Overall, our results showed that 12(S)-HETE attenuated TNF-α expression and secretion by inhibiting the mitogen-activated protein kinase ERK/NF-κB and C/EBPβ signaling pathways. Overall, these results suggest that 12(S)-HETE effectively resolved TNF-α-induced inflammation.

C/EBPβ deficiency enhances the keratinocyte innate immune response to direct activators of cytosolic pattern recognition receptors

The skin is the first line of defense to cutaneous microbes and viruses, and epidermal keratinocytes play a critical role in preventing infection by viruses and pathogens through activation of the type I interferon (IFN) response. Using RNAseq analysis, here we report that the conditional deletion of C/EBPβ transcription factor in mouse epidermis (CKOβ mice) resulted in the upregulation of IFNβ and numerous keratinocyte interferon-stimulated genes (ISGs). The expression of cytosolic pattern recognition receptors (cPRRs), that recognize viral RNA and DNA, were significantly increased, and enriched in the RNAseq data set. cPRRs stimulate a type I IFN response that can trigger cell death to eliminate infected cells. To determine if the observed increases in cPRRs had functional consequences, we transfected CKOβ primary keratinocytes with the pathogen and viral mimics poly(I:C) (dsRNA) or poly(dA:dT) (synthetic B-DNA) that directly activate PRRs. Transfected CKOβ primary keratinocytes displayed an amplified type I IFN response which was accompanied by increased activation of IRF3, enhanced ISG expression, enhanced activation of caspase-8, caspase-3 and increased apoptosis. Our results identify C/EBPβ as a critical repressor of the keratinocyte type I IFN response, and demonstrates that the loss of C/EBPβ primes keratinocytes to the activation of cytosolic PRRs by pathogen RNA and DNA to induce cell death mediated by caspase-8 and caspase-3.

ERK5 modulates IL-6 secretion and contributes to tumor-induced immune suppression

Tumors exhibit a variety of strategies to dampen antitumor immune responses. With an aim to identify factors that are secreted from tumor cells, we performed an unbiased mass spectrometry-based secretome analysis in lung cancer cells. Interleukin-6 (IL-6) has been identified as a prominent factor secreted by tumor cells and cancer-associated fibroblasts isolated from cancer patients. Incubation of dendritic cell (DC) cultures with tumor cell supernatants inhibited the production of IL-12p70 in DCs but not the surface expression of other activation markers which is reversed by treatment with IL-6 antibody. Defects in IL-12p70 production in the DCs inhibited the differentiation of Th1 but not Th2 and Th17 cells from naïve CD4⁺ T cells. We also demonstrate that the classical mitogen-activated protein kinase, ERK5/MAPK7, is required for IL-6 production in tumor cells. Inhibition of ERK5 activity or depletion of ERK5 prevented IL-6 production in tumor cells, which could be exploited for enhancing antitumor immune responses.

Association of Tumour Microenvironment with Protein Glycooxidation, DNA Damage, and Nitrosative Stress in Colorectal Cancer

Purpose

In this study, we evaluated the total antioxidant capacity, nitrosative stress, and protein/DNA oxidation and glycoxidation products in patients with colorectal cancer regarding histopathological parameters associated with the tumour microenvironment, such as inflammatory infiltration and tumour budding and compare all determined parameters between tumours located in the right and left side of the colon and normal mucosa.

Patients and Methods

Ferric reducing antioxidant power (FRAP), nitrosative stress (myeloperoxidase (MPO), nitrogen oxide (NO), peroxynitrite, and nitrotyrosine), protein oxidation products (protein carbonyls (PC), total thiols, and ischemia modified albumin (IMA)), protein glycooxidation products (tryptophan, kynurenine, N-formylkynurenine, dityrosine, Amadori product, advanced glycation end products (AGE)) and 8-hydroxydeoxyguanosine (8-OHdG) were measured in homogenates from normal and cancerous tissue of 30 patients with colorectal cancer.

Results

Levels of FRAP (p=0.0009), IMA (p=0.0002), kynurenine (p<0.0001), N-formylkynurenine (p<0.0001), dityrosine (p<0.0001), Amadori products (p=0.0024), AGE (p<0.0001), MPO (p<0.0001), NO (p<0.0001) and nitrotyrosine (p=0.0011) were increased, whereas PC (p=0.0004), tryptophan (p<0.0001), 8-OHdG (p<0.0001) and peroxynitrite (p=0.0003) were decreased in the left-side tumour compared to the right-side tumour and normal mucosa.

Conclusion

Our results showed that colorectal cancer is related with disturbances in antioxidant defense and increased oxidative and nitrosative damages to proteins and DNA. These parameters may be useful for evaluation the progression and differentiation of the tumour location. We also demonstrated that redox indicators may depend on the histological type of the tumour and may influence tumour invasion depth, presence of lymph node and distant metastasis, vascular and neural invasion, inflammatory infiltration, and tumour budding, which are part of the tumour microenvironment.

RNA-induced liquid phase separation of SARS-CoV-2 nucleocapsid protein facilitates NF-κB hyper-activation and inflammation

The ongoing 2019 novel coronavirus disease (COVID-19) caused by SARS-CoV-2 has posed a worldwide pandemic and a major global public health threat. The severity and mortality of COVID-19 are associated with virus-induced dysfunctional inflammatory responses and cytokine storms. However, the interplay between host inflammatory responses and SARS-CoV-2 infection remains largely unknown. Here, we demonstrate that SARS-CoV-2 nucleocapsid (N) protein, the major structural protein of the virion, promotes the virus-triggered activation of NF-κB signaling. After binding to viral RNA, N protein robustly undergoes liquid-liquid phase separation (LLPS), which recruits TAK1 and IKK complex, the key kinases of NF-κB signaling, to enhance NF-κB activation. Moreover, 1,6-hexanediol, the inhibitor of LLPS, can attenuate the phase separation of N protein and restrict its regulatory functions in NF-κB activation. These results suggest that LLPS of N protein provides a platform to induce NF-κB hyper-activation, which could be a potential therapeutic target against COVID-19 severe pneumonia.

Inducible nitric oxide synthase (iNOS) mediates ethanol-induced redox imbalance and upregulation of inflammatory cytokines in the kidney

Overexpression of the inducible isoform of the enzyme nitric oxide synthase (iNOS) has been associated to pathological processes in the kidney. Ethanol consumption induces the renal expression of iNOS; however, the contribution of this enzyme to the deleterious effects of ethanol in the kidney remains elusive. We examined whether iNOS plays a role in the renal dysfunction and oxidative stress induced by ethanol consumption. With this purpose, male C57BL/6 wild-type (WT) or iNOS-deficient (iNOS^-/-) mice were treated with ethanol (20% v/v) for 10 weeks. Treatment with ethanol increased the expression of Nox4 as well as the concentration of thiobarbituric acid reactive substances and the levels of tumor necrosis factor α in the renal cortex of WT but not iNOS^-/- mice. Augmented serum levels of creatinine and increased systolic blood pressure were found in WT and iNOS^-/- mice treated with ethanol. WT mice treated with ethanol showed increased production of reactive oxygen species and myeloperoxidase activity, but these responses were attenuated in iNOS^-/- mice. We concluded that iNOS played a role in ethanol-induced oxidative stress and pro-inflammatory cytokine production in the kidney. These are mechanisms that may contribute to the renal toxicity induced by ethanol.

CD200:CD200R Interactions and Their Importance in Immunoregulation

The molecule CD200, described many years ago as a naturally occurring immunomodulatory agent, capable of regulating inflammation and transplant rejection, has attracted additional interest over the past years with the realization that it may also serve as an important marker for progressive malignancy. A large body of evidence also supports the hypothesis that this molecule can contribute to immunoregulation of, among other diseases, infection, autoimmune disease and allergy. New data have also come to light to characterize the receptors for CD200 (CD200R) and their potential mechanism(s) of action at the biochemical level, as well as the description of a novel natural antagonist of CD200, lacking the NH₂-terminal region of the full-length molecule. Significant controversies exist concerning the relative importance of CD200 as a ligand for all reported CD200Rs. Nevertheless, some progress has been made in the identification of the structural constraints determining the interaction between CD200 and CD200R, and this information has in turn proved of use in developing novel small molecule agonists/antagonists of the interaction. The review below highlights many of these newer findings, and attempts to place them in the broad context of our understanding of the role of CD200-CD200R interactions in a variety of human diseases.

Lactate Suppresses Macrophage Pro-Inflammatory Response to LPS Stimulation by Inhibition of YAP and NF-κB Activation via GPR81-Mediated Signaling

Recent evidence from cancer research indicates that lactate exerts a suppressive effect on innate immune responses in cancer. This study investigated the mechanisms by which lactate suppresses macrophage pro-inflammatory responses. Macrophages [Raw 264.7 and bone marrow derived macrophages (BMDMs)] were treated with LPS in the presence or absence of lactate. Pro-inflammatory cytokines, NF-κB and YAP activation and nuclear translocation were examined. Our results show that lactate significantly attenuates LPS stimulated macrophage TNF-α and IL-6 production. Lactate also suppresses LPS stimulated macrophage NF-κB and YAP activation and nuclear translocation in macrophages. Interestingly, YAP activation and nuclear translocation are required for LPS stimulated macrophage NF-κB activation and TNFα production. Importantly, lactate suppressed YAP activation and nuclear translocation is mediated by GPR81 dependent AMKP and LATS activation which phosphorylates YAP, resulting in YAP inactivation. Finally, we demonstrated that LPS stimulation induces an interaction between YAP and NF-κB subunit p65, while lactate decreases the interaction of YAP and NF-κB, thus suppressing LPS induced pro-inflammatory cytokine production. Our study demonstrates that lactate exerts a previously unknown role in the suppression of macrophage pro-inflammatory cytokine production via GPR81 mediated YAP inactivation, resulting in disruption of YAP and NF-κB interaction and nuclear translocation in macrophages.

The effects of the genetic polymorphisms of antioxidant enzymes on susceptibility to papillary thyroid carcinoma

Several lines of evidences have indicated that inflammation play an important role in the carcinogenesis. During the inflammatory processes, free radical species are produced from oxidative stress. In normal conditions, enzymatic and nonenzymatic antioxidants remove these products. Manganese superoxide dismutase (MnSOD), glutathione peroxidase-1 (GPx-1), and catalase (CAT) are three important enzymes. Therefore, this study aimed to evaluate the effects of MnSOD (SOD2), GPX-1, and CAT genetic polymorphisms on papillary thyroid carcinoma (PTC) susceptibility. A total of 134 patients with PTC and 151 healthy controls were recruited to participate in this study. All samples were genotyped for SOD2 rs4880, GPX1 1050450, and CAT rs7943316 polymorphisms by polymerase chain reaction-restriction fragment length polymorphism method. The frequencies of the rs1050450, rs4880, and rs7943316 alleles and genotypes were not different between PTC patients and controls. However, the TC genotype of SOD2 rs4880 polymorphism was significantly higher in males compared to that in females in PTC patients (odds ratio [OR], 3.9 [95% CI, 1.5-11], p = .007). The rs4880 polymorphism was also associated with higher stages (III-IV) of PTC in dominant model. No significant correlation was found between GPX1-rs1050450 and CAT-rs7943316 polymorphisms and demographic, clinical, and pathological features of the disease. The SOD2 rs4880CT genotype was more frequent in males with PTC and patients with higher stages (III-IV) of disease (OR, 2.9 [95% CI, 1.1-7.7], p = .04). However, no significant association was found between GPX1-rs1050450 and CAT-rs7943316 variants and PTC or its demographic, clinical, and pathological features.

Novel Plaque Enriched Long Noncoding RNA in Atherosclerotic Macrophage Regulation (PELATON)

OBJECTIVE

Long noncoding RNAs (lncRNAs) are an emergent class of molecules with diverse functional roles, widely expressed in human physiology and disease. Although some lncRNAs have been identified in cardiovascular disease, their potential as novel targets in the prevention of atherosclerosis is unknown. We set out to discover important lncRNAs in unstable plaque and gain insight into their functional relevance. Approach and Results: Analysis of RNA sequencing previously performed on stable and unstable atherosclerotic plaque identified a panel of 47 differentially regulated lncRNAs. We focused on LINC01272, a lncRNA upregulated in unstable plaque previously detected in inflammatory bowel disease, which we termed PELATON (plaque enriched lncRNA in atherosclerotic and inflammatory bowel macrophage regulation). Here, we demonstrate that PELATON is highly monocyte- and macrophage-specific across vascular cell types, and almost entirely nuclear by cellular fractionation (90%-98%). In situ hybridization confirmed enrichment of PELATON in areas of plaque inflammation, colocalizing with macrophages around the shoulders and necrotic core of human plaque sections. Consistent with its nuclear localization, and despite containing a predicted open reading frame, PELATON did not demonstrate any protein-coding potential in vitro. Functionally, knockdown of PELATON significantly reduced phagocytosis, lipid uptake and reactive oxygen species production in high-content analysis, with a significant reduction in phagocytosis independently validated. Furthermore, CD36, a key mediator of phagocytic oxLDL (oxidized low-density lipoprotein) uptake was significantly reduced with PELATON knockdown.

CONCLUSIONS

PELATON is a nuclear expressed, monocyte- and macrophage-specific lncRNA, upregulated in unstable atherosclerotic plaque. Knockdown of PELATON affects cellular functions associated with plaque progression.

CCAAT/enhancer-binding protein beta (C/EBPβ) knockdown reduces inflammation, ER stress, and apoptosis, and promotes autophagy in oxLDL-treated RAW264.7 macrophage cells

Atherosclerosis is associated with deregulated cholesterol metabolism and formation of macrophage foam cells. CCAAT/enhancer-binding protein beta (C/EBPβ) is a transcription factor, and its inhibition has recently been shown to prevent atherosclerosis development and foam cell formation. However, whether C/EBPβ regulates inflammation, endoplasmic reticulum (ER) stress, and apoptosis, in macrophage foam cells and its underlying molecular mechanism remains unknown. Here, we investigated the effect of C/EBPβ knockdown on proteins and genes implicated in inflammation, ER stress, apoptosis, and autophagy in macrophage foam cells. RAW264.7 macrophage cells were transfected with control and C/EBPβ-siRNA and then treated with nLDL and oxLDL. Key proteins and genes involved in inflammation, ER stress, apoptosis, and autophagy were analyzed by western blot and qPCR. We found that short interfering RNA (siRNA)-mediated knockdown of C/EBPβ attenuated atherogenic lipid-mediated induction of proteins and genes implicated in inflammation (P-NFkB-p65, NFkB-p65, and TNFα), ER stress (ATF4 and ATF6), and apoptosis (CHOP, caspase 1, 3, and 12). Interestingly, C/EBPβ knockdown upregulated the expression of autophagy proteins (LC3A/B-II, ATG5) and genes (LC3B, ATG5) but decreased the mammalian target of rapamycin (mTOR) protein phosphorylation and mTORC1 gene expression in oxLDL-loaded RAW264.7 macrophage cells. More importantly, treatment with rapamycin (inhibitor of mTOR) increased expression of proteins implicated in autophagy and cholesterol efflux in oxLDL-loaded RAW 264.7 macrophage cells. The present results suggest that C/EBPβ inactivation regulates macrophage foam cell formation in atherogenesis by reducing inflammation, ER stress, and apoptosis and by promoting autophagy and inactivating mTOR.

Molecular Mechanism of Aniline Induced Spleen Toxicity and Neuron Toxicity in Experimental Rat Exposure: A Review

Aniline exposure leads to neuron and spleen toxicity specifically and makes diverse neurological effects and sar-coma that is defined by splenomegaly, hyperplasia, and fibrosis and tumors formation at the end. However, the molecular mechanism(s) of aniline-induced spleen toxicity is not understood well, previous studies have represented that aniline expo-sure results in iron overload and initiation of oxidative/nitrosative disorder stress and oxidative damage to proteins, lipids and DNA subsequently, in the spleen. Elevated expression of cyclins, cyclin-dependent kinases (CDKs) and phosphorylation of pRB protein along with increases in A, B and CDK1 as a cell cycle regulatory proteins cyclins, and reduce in CDK inhibitors (p21 and p27) could be critical in cell cycle regulation, which contributes to tumorigenic response after aniline exposure. Aniline-induced splenic toxicity is corre-lated to oxidative DNA damage and initiation of DNA glycosylases expression (OGG1, NEIL1/2, NTH1, APE1 and PNK) for removal of oxidative DNA lesions in rat. Oxidative stress causes transcriptional up-regulation of fibrogenic/inflammatory factors (cytokines, IL-1, IL-6 and TNF-α) via induction of nuclear factor-kappa B, AP-1 and redox-sensitive transcription factors, in aniline treated-rats. The upstream signalling events as phosphorylation of IκB kinases (IKKα and IKKβ) and mito-gen-activated protein kinases (MAPKs) could potentially be the causes of activation of NF-κB and AP-1. All of these events could initiate a fibrogenic and/or tumorigenic response in the spleen. The spleen toxicity of aniline is studied more and the different mechanisms are suggested. This review summarizes those events following aniline exposure that induce spleen tox-icity and neurotoxicity.

The Role of NADPH Oxidases and Oxidative Stress in Neurodegenerative Disorders

For a number of years, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOX) was synonymous with NOX2/gp91^phox and was considered to be a peculiarity of professional phagocytic cells. Over the last decade, several more homologs have been identified and based on current research, the NOX family consists of NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1 and DUOX2 enzymes. NOXs are electron transporting membrane proteins that are responsible for reactive oxygen species (ROS) generation-primarily superoxide anion (O₂^●-), although hydrogen peroxide (H₂O₂) can also be generated. Elevated ROS leads to oxidative stress (OS), which has been associated with a myriad of inflammatory and degenerative pathologies. Interestingly, OS is also the commonality in the pathophysiology of neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). NOX enzymes are expressed in neurons, glial cells and cerebrovascular endothelial cells. NOX-mediated OS is identified as one of the main causes of cerebrovascular damage in neurodegenerative diseases. In this review, we will discuss recent developments in our understanding of the mechanisms linking NOX activity, OS and neurodegenerative diseases, with particular focus on the neurovascular component of these conditions. We conclude highlighting current challenges and future opportunities to combat age-related neurodegenerative disorders by targeting NOXs.

A case-control study of the genetic polymorphism of IL6 and HAPE risk in a Chinese Han population

AIMS

The role of inflammatory cytokines in High-altitude pulmonary edema (HAPE) remains unclear. The purpose of this study was to evaluate the role of IL4 and IL6 gene polymorphism in the development of HAPE in Chinese people.

METHODS

In the present study, we screened ten polymorphisms of IL4 and IL6 gene in 265 HAPE and 303 healthy volunteers. Genotypes were determined using the Sequenom MassARRAY method. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression.

RESULTS

Two single-nucleotide polymorphisms (SNPs) in the IL6 gene were significantly associated with HAPE. Rs1800796 and rs1524107 (G vs C, OR = 1.31, 95%CI = 1.01-1.69, P = .041 and T vs C, OR = 1.35, 95%CI = 1.05-1.74, P = .020, respectively). However, there did not found any association for IL4 gene.

CONCLUSION

Inflammatory cytokines may play a role in the progress of HAPE. These polymorphisms could be genetic markers for predicting the susceptibility to HAPE.

Nebulized lidocaine ameliorates allergic airway inflammation via downregulation of TLR2

Nebulized lidocaine has been suggested to be beneficial in asthma therapy, but the underlying mechanisms are little known. We aimed to investigate whether Toll-like receptor (TLR) 2 was involved in the protective effect of lidocaine on allergic airway inflammation. Female C57BL/6 mice were sensitized and challenged with ovalbumin (OVA). Meanwhile, some of the mice were treated with TLR2 agonist (Pam3CSK4, 100 μg) intraperitoneally in combination with OVA on day 0. Just after allergen provocation, mice were treated with inhaled lidocaine or vehicle for 30 min. In this model, we found that lidocaine markedly attenuated OVA-evoked airway inflammation, leukocyte recruitment and mucus production. Moreover, lidocaine abrogated the increased concentrations of T cytokines and TNF-α in bronchoalveolar lavage fluid (BALF) of allergic mice, as well as reducing the expression of phosphorylated nuclear factor (P-NF)-κBp65 and the NOD-like receptor pyridine containing 3 (NLRP3), which are important for the production of pro-inflammatory cytokines. In addition, our study showed that lidocaine dramatically decreased OVA-induced increased expression of TLR2 in the lung tissues. Furthermore, activation of TLR2 aggravated OVA-challenged airway inflammation, meanwhile, it also elevated OVA-induced expression of P-NF-κBp65 and NLRP3 in the lungs. However, lidocaine effectively inhibited airway inflammation and counteracted the expression of P-NF-κBp65 and NLRP3 in allergic mice pretreated with Pam3CSK4. Taken together, the present study demonstrated that lidocaine prevented allergic airway inflammation via TLR2 in an OVA-induced murine allergic airway inflammation model. TLR2/NF-κB/NLRP3 pathway may serve as a promising therapeutic strategy for allergic airway inflammation.

Grass Carp Prolactin Gene: Structural Characterization and Signal Transduction for PACAP-induced Prolactin Promoter Activity

In this study, structural analysis of grass carp prolactin (PRL) gene was performed and the signaling mechanisms for pituitary adenylate cyclase-activating peptide (PACAP) regulation of PRL promoter activity were investigated. In αT3-1 cells, PRL promoter activity could be induced by oPACAP₃₈ which was blocked by PACAP antagonist but not the VIP antagonist. The stimulatory effect of oPACAP₃₈ was mimicked by activation of AC/cAMP and voltage-sensitive Ca²⁺ channel (VSCC) signaling, or induction of Ca²⁺ entry. In parallel, PACAP-induced PRL promoter activity was negated or inhibited by suppressing cAMP production, inhibiting PKA activity, removal of extracellular Ca²⁺, VSCC blockade, calmodulin (CaM) antagonism, and inactivation of CaM kinase II. Similar sensitivity to L-type VSCC, CaM and CaM kinase II inhibition were also observed by substituting cAMP analog for oPACAP₃₈ as the stimulant for PRL promoter activity. Moreover, PACAP-induced PRL promoter activity was also blocked by inhibition of PLC signaling, attenuation of [Ca²⁺]i immobilization via IP3 receptors, and blockade of PI3K/P₇₀^S6K pathway. The PACAP-induced PRL promoter activation may involve transactivation of the transcription factor CREB. These results suggest that PACAP can stimulate PRL promoter activation by PAC1 mediated functional coupling of the Ca²⁺/CaM/CaM kinase II cascades with the AC/cAMP/PKA pathway. Apparently, other signaling pathways, including PLC/IP3 and PI3K/P₇₀^S6K cascades, may also be involved in PACAP induction of PRL gene transcription.

Characteristic pro-inflammatory cytokines and host defence cathelicidin peptide produced by human monocyte-derived macrophages infected withNeospora caninum

Neospora caninumis a coccidian intracellular protozoan capable of infecting a wide range of mammals, although severe disease is mostly reported in dogs and cattle. Innate defences triggered by monocytes/macrophages are key in the pathogenesis of neosporosis, as these cells are first-line defenders against intracellular infections. The aim of this study was to characterize infection and innate responses in macrophages infected withN. caninumusing a well-known cell model to study macrophage functions (human monocyte THP-1 cells). Intracellular invasion of live tachyzoites occurred as fast as 4 h (confirmed with immunofluorescence microscopy usingN. caninum-specific antibodies). Macrophages infected byN. caninumhad increased expression of pro-inflammatory cytokines (TNFα, IL-1β, IL-8, IFNγ). Interestingly,N. caninuminduced expression of host-defence peptides (cathelicidins), a mechanism of defence never reported forN. caninuminfection in macrophages. The expression of cytokines and cathelicidins in macrophages invaded byN. caninumwas mediated by mitogen-activated protein kinase (MEK 1/2). Secretion of such innate factors fromN. caninum-infected macrophages reduced parasite internalization and promoted the secretion of pro-inflammatory cytokines in naïve macrophages. We concluded that rapid invasion of macrophages byN. caninumtriggered protective innate defence mechanisms against intracellular pathogens.

Syk inhibitor R406 downregulates inflammation in an in vitro model of Pseudomonas aeruginosa infection

As Pseudomonas aeruginosa infections are characterized by strong inflammation of infected tissues, anti-inflammatory therapies in combination with antibiotics have been considered for the treatment of associated diseases. Syk tyrosine kinase is an important regulator of inflammatory responses, and its specific inhibition was explored as a therapeutic option in several inflammatory conditions; however, this has not been studied in bacterial infections. We used a model of in vitro infection of human monocytic cell line THP-1 and lung epithelial cell line H292 with both wild-type and flagella-deficient mutant of P. aeruginosa strain K, as well as with clinical isolates from cystic fibrosis patients, to study the effect of a small molecule Syk inhibitor R406 on inflammatory responses induced by this pathogen. One-hour pretreatment of THP-1 cells with 10 μmol/L R406 resulted in a significant downregulation of the expression of the adhesion molecule ICAM-1, pro-inflammatory cytokines TNF-α and IL-1β, and phosphorylated signaling proteins ERK2, JNK, p-38, and IκBα, as well as significantly decreased TNF-α release by infected H292 cells. The results suggest that Syk is involved in the regulation of inflammatory responses to P. aeruginosa, and R406 may potentially be useful in dampening the damage caused by severe inflammation associated with this infection.

Hall of Fame among Pro-inflammatory Cytokines: Interleukin-6 Gene and Its Transcriptional Regulation Mechanisms

Pro-inflammatory cytokines that are generated by immune system cells and mediate many kinds of immune responses are kinds of endogenous polypeptides. They are also the effectors of the autoimmune system. It is generally accepted that interleukin (IL)-4, IL-6, IL-9, IL-17, and tumor necrosis factor-α are pro-inflammatory cytokines; however, IL-6 becomes a protagonist among them since it predominately induces pro-inflammatory signaling and regulates massive cellular processes. It has been ascertained that IL-6 is associated with a large number of diseases with inflammatory background, such as anemia of chronic diseases, angiogenesis acute-phase response, bone metabolism, cartilage metabolism, and multiple cancers. Despite great progress in the relative field, the targeted regulation of IL-6 response for therapeutic benefits remains incompletely to be understood. Therefore, it is conceivable that understanding mechanisms of IL-6 from the perspective of gene regulation can better facilitate to determine the pathogenesis of the disease, providing more solid scientific basis for clinical treatment translation. In this review, we summarize the candidate genes that have been implicated in clinical target therapy from the perspective of gene transcription regulation.

A meta-analysis of blood cytokine network alterations in psychiatric patients: comparisons between schizophrenia, bipolar disorder and depression

Schizophrenia, bipolar disorder and major depressive disorder (MDD) have all been associated with aberrant blood cytokine levels; however, neither the pattern of cytokine alterations nor the impact of clinical status have been compared across disorders. We performed a meta-analysis of blood cytokines in acutely and chronically ill patients with these major psychiatric disorders. Articles were identified by searching the PubMed, PsycInfo and Web of Science, and the reference lists of these studies. Sixty-eight studies met the inclusion criteria (40 schizophrenia, 10 bipolar disorder and 18 MDD) for acutely ill patients. Forty-six studies met the inclusion criteria (18 schizophrenia, 16 bipolar disorder and 12 MDD) for chronically ill patients. Levels of two cytokines (interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)), one soluble cytokine receptor (sIL-2R), and one cytokine receptor antagonist (IL-1RA) were significantly increased in acutely ill patients with schizophrenia, bipolar mania and MDD compared with controls (P<0.01). Following treatment of the acute illness, IL-6 levels significantly decreased in both schizophrenia and MDD (P<0.01); sIL-2R levels increased in schizophrenia; and IL-1RA levels in bipolar mania decreased. In chronically ill patients, the levels of IL-6 were significantly increased in schizophrenia, euthymic (but not depressed) bipolar disorder and MDD compared with controls (P<0.01). The levels of IL-1β and sIL-2R were significantly increased in both chronic schizophrenia and euthymic bipolar disorder. Overall, there were similarities in the pattern of cytokine alterations in schizophrenia, bipolar disorder and MDD during acute and chronic phases of illness, raising the possibility of common underlying pathways for immune dysfunction. Effects of treatment on cytokines were more robust for schizophrenia and MDD, but were more frequently studied than for acute mania. These findings have important implications for our understanding of the pathophysiology and treatment of major psychiatric disorders.

Endothelium-Derived 5-Methoxytryptophan Is a Circulating Anti-Inflammatory Molecule That Blocks Systemic Inflammation

Rationale:

Systemic inflammation has emerged as a key pathophysiological process that induces multiorgan injury and causes serious human diseases. Endothelium is critical in maintaining cellular and inflammatory homeostasis, controlling systemic inflammation, and progression of inflammatory diseases. We postulated that endothelium produces and releases endogenous soluble factors to modulate inflammatory responses and protect against systemic inflammation.

Objective:

To identify endothelial cell–released soluble factors that protect against endothelial barrier dysfunction and systemic inflammation.

Methods and Results:

We found that conditioned medium of endothelial cells inhibited cyclooxgenase-2 and interleukin-6 expression in macrophages stimulated with lipopolysaccharide. Analysis of conditioned medium extracts by liquid chromatography–mass spectrometry showed the presence of 5-methoxytryptophan (5-MTP), but not other related tryptophan metabolites. Furthermore, endothelial cell–derived 5-MTP suppressed lipopolysaccharide-induced inflammatory responses and signaling in macrophages and endotoxemic lung tissues. Lipopolysaccharide suppressed 5-MTP level in endothelial cell-conditioned medium and reduced serum 5-MTP level in the murine sepsis model. Intraperitoneal injection of 5-MTP restored serum 5-MTP accompanied by the inhibition of lipopolysaccharide-induced endothelial leakage and suppression of lipopolysaccharide- or cecal ligation and puncture–mediated proinflammatory mediators overexpression. 5-MTP administration rescued lungs from lipopolysaccharide-induced damages and prevented sepsis-related mortality. Importantly, compared with healthy subjects, serum 5-MTP level in septic patients was decreased by 65%, indicating an important clinical relevance.

Conclusions:

We conclude that 5-MTP belongs to a novel class of endothelium-derived protective molecules that defend against endothelial barrier dysfunction and excessive systemic inflammatory responses.

sn-1,2-diacylglycerols protect against lethal endotoxemia by controlling systemic inflammation

Systemic inflammation has emerged as a key pathophysiological process that induces multiple organ injuries and causes serious human diseases. Despite substantial evidence supporting the role of diacylglycerols (DAG) in modulating chronic inflammation and chronic diseases, the potential mechanisms of its involvement in TLRs-mediated inflammation are still unclear. Here, we show that sn-1,2-diacylglycerols modulate LPS/TLR4-mediated inflammation in vitro and in vivo. ELISA and western blotting experiments indicated that sn-1,2-diacylglycerols suppress LPS-induced responses, including IL-6 and TNF-α production, and COX-2 expression in mouse RAW264.7 macrophages and human endothelial cells, in a dose-dependent manner. Using LPS-induced murine model of systemic inflammation, we show that sn-1,2-diacylglycerols block the cytokine storm, the expression of inflammatory mediators, and LPS-induced septic lung damage and mortality. sn-1,2-diacylglycerols reduce systemic inflammation by inhibiting LPS-induced p38 MAPK- and PI3K/AKT-mediated NF-κB activation in macrophages. These results suggest that exogenous DAG probably acts by blocking p38 MAPK or PI3K/AKT signal transduction, thereby down-regulating NF-κB activation and NF-κB-mediated transcription of genes encoding cytokines and pro-inflammatory oxidative enzymes. Our findings demonstrate that exogenous sn-1,2-diacylglycerol protects mice from LPS-induced lethal endotoxemia by suppressing TLR4-driven inflammatory responses, suggesting that 1,2-diacylglycerols may be used as dietary health supplements for the prevention or therapy of systemic inflammatory diseases.

Interleukin-4 receptor signaling and its binding mechanism: A therapeutic insight from inhibitors tool box

Studies on Interlukin-4 (IL-4) disclosed great deal of information about its various physiological and pathological roles. All these roles depend upon its interaction and signaling through either type-I (IL-4Rα/common γ-chain) or type-II (IL-4Rα/IL-13Rα) receptors. Another cytokine, IL-13, shares some of the functions of IL-4, because both cytokines use a common receptor subunit, IL-4Rα. Here in this review, we discuss the structural details of IL-4 and IL-4Rα subunit and the structural similarities between IL-4 and IL-13. We also describe detailed chemistry of type-I and type-II receptor complexes and their signaling pathways. Furthermore, we elaborate the strength of type-II hetero dimer signals in response to IL-4 and IL-13. These cytokines are prime players in pathogenesis of allergic asthma, allergic hypersensitivity, different cancers, and HIV infection. Recent advances in the structural and binding chemistry of these cytokines various types of inhibitors were designed to block the interaction of IL-4 and IL-13 with their receptor, including several IL-4 mutant analogs and IL-4 antagonistic antibodies. Moreover, different targeted immunotoxins, which is a fusion of cytokine protein with a toxin or suicidal gene, are the new class of inhibitors to prevent cancer progression. In addition few small molecular inhibitors such as flavonoids have also been developed which are capable of binding with high affinity to IL-4Rα and, therefore, can be very effective in blocking IL-4-mediated responses.

BTK mutations selectively regulate BTK expression and upregulate monocyte XBP1 mRNA in XLA patients

Mutations in the Bruton agammaglobulinemia tyrosine kinase (BTK) gene are responsible for X-linked agammaglobulinemia (XLA). Unfolded or misfolded proteins can trigger stress pathways in the endoplasmic reticulum (ER), known as unfolded protein response (UPR). The aim was to clarify the involvement of UPR in XLA pathophysiology. By reverse transcription-quantitative PCR, we evaluated the expression of BTK and 12 UPR-related genes in eight patients. Moreover, we assessed the BTK protein expression and pattern in the patients' monocytes by flow cytometry and fluorescence immunocytochemistry. We found a reduced BTK expression in patients with stop codon mutations (P < 0.02). However, missense mutations did not affect BTK expression. Flow cytometry showed a reduction of BTK in patients which was corroborated by an absent or nonfunctional protein synthesis revealed by immunocytochemistry. In contrast with the other UPR-related genes, X-box binding protein 1 (XBP1) was markedly upregulated in the patients (P < 0.01), suggesting Toll-like receptor (TLR) activation since BTK directly interacts with TLRs as a negative regulator and XBP1 can be activated in direct response to TLR ligation. Different BTK mutations can be identified by the BTK expression. Inasmuch as UPR-related genes were downregulated or unaltered in patients, we speculate the involvement of the TLRs-XBP1 axis in the XLA pathophysiology. Such data could be the basis for further studies of this novel pathomechanism concerning XLA.

Interferons, signal transduction pathways, and the central nervous system

The interferon (IFN) family of cytokines participates in the development of innate and acquired immune defenses against various pathogens and pathogenic stimuli. Discovered originally as a proteinaceous substance secreted from virus-infected cells that afforded immunity to neighboring cells from virus infection, these cytokines are now implicated in various human pathologies, including control of tumor development, cell differentiation, and autoimmunity. It is now believed that the IFN system (IFN genes and the genes induced by them, and the factors that regulate these processes) is a generalized alarm of cellular stress, including DNA damage. IFNs exert both beneficial and deleterious effects on the central nervous system (CNS). Our knowledge of the IFN-regulated processes in the CNS is far from being clear. In this article, we reviewed the current understanding of IFN signal transduction pathways and gene products that might have potential relevance to diseases of the CNS.

Characterizing the DNA binding site specificity of NF-κB with protein-binding microarrays (PBMs)

NF-κB transcription factors control a wide array of important cellular and organismal processes in eukaryotes. All NF-κB transcription factors bind to DNA target sites as dimers. In vertebrates, there are five NF-κB subunits, p50, p52, RelA (p65), c-Rel, and RelB, that can form almost all combinations of homodimers and heterodimers, which recognize distinct, but overlapping, target sequences. In this chapter, we describe the use of protein-binding microarrays (PBMs), a high-throughput method to measure the binding of proteins to different DNA sequences. PBM datasets allow for sensitive comparisons of NF-κB dimer DNA-binding differences and can aid in the computational and experimental prediction of NF-κB target genes.

Differential Measurements of Oxidatively Modified Proteins in Colorectal Adenopolyps

Introduction

Adenopolyps patients have a three-fold higher risk of colon cancer over the general population, which increases to six-fold if the polyps are multiple and with lower survival among African American population. Currently, 6% of CRC can be ascribed to mutations in particular genes. Moreover, the optimal management of patients with colorectal adenopolyps depends on the accuracy of appropriate staging strategies because patients with similar colorectal adenocarcinoma architecture display heterogeneity in the course and outcome of the disease. Oxidative stress, due to an imbalance between reactive oxygen species (ROS) and antioxidant capacities as well as a disruption of redox signaling, causes a wide range of damage to DNA, proteins, and lipids which promote tumor formation.

Objective/Method

This study applied spectrophotometric, dinitrophenylhydrazone (DNPH) assay, two-dimensional gel electrophoresis, and western blot analyses to assess the levels of oxidatively modified proteins in 41 pairs of primary colorectal tissues including normal/surrounding, adenopolyps (tubular, tubulovillous, villous, polypvillous) and carcinoma. Analysis of variance (ANOVA) and Student’s t-tests were utilized for the resulting data set.

Results

Our data showed that the levels of reactive protein carbonyl groups significantly increased as colorectal adenopolyps progresses to malignancy. No significant differences were found in the levels of carbonyl proteins between gender samples analyzed. For African American patients, there were, relative to Caucasians, 10% higher levels of reactive carbonyls in proteins of tubulovillous tissue samples (P < 0.05) and over 36% higher in levels in adenocarcinomas (P < 0.05). In normal tissues and tubular, there were no significant differences between the two groups in levels of protein carbonyls. Differences in the levels of protein carbonyl expression within individual patient samples with different number of tumor cells were notably evident.

Conclusion

Results suggested that oxidative stress could be involved in the modification of oxidatively carbonyl proteins in the precancer stages, leading to increased aggressiveness of colorectal polyps.

Transcription control of DAPK

Imbalanced cell death is a common phenomenon in many human diseases, including cancer. DAPK's essential function is in promoting apoptosis. DAPK interacts with stress-induced receptors through its death domain to initiate an apoptosis cascade. In addition, DAPK phosphorylates multiple cytosolic substrates and can mediate transfer of signaling pathways to the effector caspases. A series of studies demonstrated that, depending on stimuli, DAPK expression is regulated on both the transcriptional and posttranscriptional levels. Silencing of DAPK due to hypermethylation of its promoter was reported in many types of cancer. STAT3 and p52-NFkB transcription factors have been shown to down-regulate DAPK expression. In contrast, p53, C/EBP-β and Smad transcription factors bind to their specific response elements within the DAPK promoter and induce its transcription. Post-transcriptionally, DAPK undergoes alternative splicing, which results in the production of two functionally different isoforms. Moreover, miRNA 103 and miRNA 107 recently were shown to inhibit DAPK in colorectal cancer. Here we summarize our recent knowledge about transcriptional regulation of DAPK expression.

Oxidatively modified proteins in the serous subtype of ovarian carcinoma

Serous subtype of ovarian cancer is considered to originate from fallopian epithelium mucosa that has been exposed to physiological changes resulting from ovulation. Ovulation influences an increased in inflammation of epithelial ovarian cells as results of constant exposure of cells to ROS. The imbalance between ROS and antioxidant capacities, as well as a disruption of redox signaling, causes a wide range of damage to DNA, proteins, and lipids. This study applied spectrophotometric, dinitrophenylhydrazone (DNPH) assay, two-dimensional gel electrophoresis, and Western blot analyses to assess the levels of oxidatively modified proteins in 100 primary serous epithelial ovarian carcinoma and normal/surrounding tissues. These samples were obtained from 56 Caucasian and 44 African-American patients within the age range of 61 ± 10 years. Analyses showed that the levels of reactive protein carbonyl groups increased as stages progressed to malignancy. Additionally, the levels of protein carbonyls in serous ovarian carcinoma among African Americans are 40% (P < 0.05) higher relative to Caucasian at similar advanced stages. Results suggest that oxidative stress is involved in the modification of carbonyl protein groups, leading to increased aggressiveness of epithelial ovarian tumors and may contribute to the disease's invasiveness among African Americans.

Aqueous extracts of Rhizopus oryzae induced nitric oxide production in rat hepatocyte cell line RLN-10

Aqueous extracts of Rhizopus oryzae (Aq-ROU) have a broad range of physiological activity. Here we identified a new physiological effect of Aq-ROU in rat hepatocyte cell line RLN-10. Aq-ROU induced the accumulation of nitrite, a stable metabolite nitric oxide (NO), in cell culture medium and induced potent diaminofluorescein-FM diacetate staining in the cells. Real-time reverse transcriptase (RT)-PCR analysis showed marked inducible NO synthase gene expression. Additionally, markedly enhanced expression of p22(phox) and temporally increased expression of NADPH oxidase1 indicated that superoxide was produced. Nuclear translocation of nuclear factor-kappa (NF-κ) B p65 increased remarkably following Aq-ROU and following lipopolysaccharide treatment, a potent activator of NF-κB. Ammonium pyrrolidine-1-carbodithioate, an inhibitor of NF-κB, inhibited NO production following Aq-ROU treatment. Our data indicate that Aq-ROU induces NO production and potentially the production of superoxide, which may contribute to the broad range of physiological effects observed for Aq-ROU ingested by animals.

Differential effects of type I and II interferons on myeloid cells and resistance to intracellular bacterial infections

The type I and II interferons (IFNs) play important roles in regulating immune responses during viral and bacterial infections and in the context of autoimmune and neoplastic diseases. These two IFN types bind to distinct cell surface receptors that are expressed by nearly all cells to trigger signal transduction events and elicit diverse cellular responses. In some cases, type I and II IFNs trigger similar cellular responses, while in other cases, the IFNs have unique or antagonistic effects on host cells. Negative regulators of IFN signaling also modulate cellular responses to the IFNs and play important roles in maintaining immunological homeostasis. In this review, we provide an overview of how IFNs stimulate cellular responses. We discuss the disparate effects of type I and II IFNs on host resistance to certain intracellular bacterial infections and provide an overview of models that have been proposed to account for these disparate effects. Mechanisms of antagonistic cross talk between type I and II IFNs are also introduced.

Contribution of nano-copper particles to in vivo liver dysfunction and cellular damage: role of IκBα/NF-κB, MAPKs and mitochondrial signal

The present study investigated the oxidative stress responsive cell signaling in nano-copper-induced hepatic dysfunction and cell death. Exposure to nano-copper (18 nm) dose-dependently (200-600 mg/kg bw) reduced the hepatic index, caused oxidative stress and led to hepatic dysfunction. Nano-copper burden also increased the transcriptional activity of NF-κB, up-regulated the expression of phosphorylated p38, ERK1/2 and caused the reciprocal regulation of Bcl-2 family proteins, disruption of mitochondrial membrane potential, release of cytochrome C, formation of apoptosome and activation of caspase 3. DAPI staining, immunofluorescence study, FACS analysis and histological findings also support this observation. Soluble copper (Cu(+2), 110 mg/kg bw)-exposed animals were used as a positive control. Different doses of particulate and soluble forms were used in the study because of different LD(50) values. The results suggest that nano-copper induces hepatic dysfunction and cell death via the oxidative stress-dependent signaling cascades and mitochondrial event.

Oxidative stress and antioxidant defense

Reactive oxygen species (ROS) are produced by living organisms as a result of normal cellular metabolism and environmental factors, such as air pollutants or cigarette smoke. ROS are highly reactive molecules and can damage cell structures such as carbohydrates, nucleic acids, lipids, and proteins and alter their functions. The shift in the balance between oxidants and antioxidants in favor of oxidants is termed “oxidative stress.” Regulation of reducing and oxidizing (redox) state is critical for cell viability, activation, proliferation, and organ function. Aerobic organisms have integrated antioxidant systems, which include enzymatic and nonenzymatic antioxidants that are usually effective in blocking harmful effects of ROS. However, in pathological conditions, the antioxidant systems can be overwhelmed. Oxidative stress contributes to many pathological conditions and diseases, including cancer, neurological disorders, atherosclerosis, hypertension, ischemia/perfusion, diabetes, acute respiratory distress syndrome, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, and asthma. In this review, we summarize the cellular oxidant and antioxidant systems and discuss the cellular effects and mechanisms of the oxidative stress.

Japanese herbal medicine, inchinkoto, inhibits inducible nitric oxide synthase induction in interleukin-1β-stimulated hepatocytes

AIM

  A herbal medicine, kampo inchinkoto (TJ-135), is used to treat jaundice and liver fibrosis in patients with cirrhosis. In the inflamed liver, proinflammatory cytokines stimulate the induction of inducible nitric oxide synthase (iNOS) gene expression. Over-production of nitric oxide (NO) by iNOS has been implicated as a factor in liver injury. We examined interleukin (IL)-1β-stimulated hepatocytes as a simple in vitro injury model to determine liver-protective effects of TJ-135. The objective was to investigate whether TJ-135 influences iNOS induction and to determine its mechanism.

METHODS

  Primary cultured rat hepatocytes were treated with IL-1β in the presence or absence of TJ-135. The induction of iNOS and its signaling pathway were analyzed.

RESULTS

  IL-1β produced increased levels of NO. This effect was inhibited by TJ-135, which exerted its maximal effects at 3 mg/mL. TJ-135 decreased the levels of iNOS protein and its mRNA expression. Experiments with nuclear extracts revealed that TJ-135 inhibited the translocation of nuclear factor-κB (NF-κB) to the nucleus and its DNA binding. TJ-135 also inhibited the activation of Akt, resulting in the reduction of type I IL-1 receptor mRNA and protein expression. Transfection experiments with iNOS promoter-luciferase constructs demonstrated that TJ-135 suppressed iNOS induction by inhibition of promoter transactivation and mRNA stabilization. TJ-135 reduced the expression of an iNOS gene antisense-transcript. Delayed administration or withdrawal of TJ-135 after IL-1β addition also inhibited iNOS induction.

CONCLUSIONS

  RESULTS indicate that TJ-135 inhibits the induction of iNOS at both transcriptional and post-transcriptional steps, leading to the prevention of NO production. TJ-135 may have therapeutic potential for various liver injuries through the suppression of iNOS induction.

Interleukin-8 overexpression in astrocytomas is induced by prostaglandin E2 and is associated with the transcription factors CCAAT/enhancer-binding protein-β and CCAAT/enhancer-binding homologous protein

BACKGROUND

The upregulation of microsomal prostaglandin E synthase-1 (mPGES-1) and the overexpression of interleukin-8 (IL-8) have been separately linked to glioma malignancy.

OBJECTIVE

To evaluate (1) the correlation between the mRNA levels of IL-8, mPGES-1, and the main transcription factors (TFs) activating the IL-8 promoter in human brain tumors of different grades; (2) the role of prostaglandin E2 (PGE2) on IL-8 activation and the expression of these TFs in tumor-derived cells; and (3) the biological impact of PGE2 treatment and mPGES-1 silencing on IL-8 synthesis and tumorigenesis.

METHODS

Quantitative real-time polymerase chain reaction, transfection experiments, and cell proliferation and apoptosis assays were performed.

RESULTS

Regardless of histological grade, a significant positive association between IL-8 expression and mPGES-1, CCAAT/enhancer-binding protein-β (C/EBP-β) and C/EBP Homologous Protein (CHOP) mRNA levels was found only in astrogliomas (P < .001). The correlation was not significant in the other brain tumors. PGE2-treated astroglioma cells showed a marked upregulation of IL-8, C/EBP-β, and CHOP, as well as increased proliferation and decreased apoptosis compared with untreated cells. mPGES-1-silenced astroglioma cells displayed decreased IL-8 synthesis, accompanied by reduced cell growth and an increased rate of apoptosis. The other brain tumor cells were unaffected either by PGE2 treatment or by mPGES-1 knockout.

CONCLUSION

(1) PGE2 is responsible for IL-8 overexpression, independently of the malignancy grade, in astrogliomas only. (2) C/EBP-β and CHOP may be involved in mediating PGE2-induced IL-8 activation in these tumors. (3) mPGES-1 inhibition may have potential as a form of adjuvant therapy for astrogliomas.

Neuroadaptive changes in cerebellar neurons induced by chronic exposure to IL-6

IL-6 is an important signaling molecule in the CNS. CNS neurons express IL-6 receptors and their signal transduction molecules, consistent with a role for IL-6 in neuronal physiology. Research indicates that IL-6 levels are low in the normal brain but can be significantly elevated in CNS injury and disease. Relatively little is known about how the elevated levels of IL-6 affect neurons. In the current study we show that under conditions of chronic exposure, IL-6 induces alterations in the level of protein expression in developing CNS cells. Such changes may play a role in the altered CNS function observed in CNS conditions associated with elevated levels of IL-6 in the CNS.

The CCAAT/enhancer binding protein (C/EBP) δ is differently regulated by fibrillar and oligomeric forms of the Alzheimer amyloid-β peptide

Background

The transcription factors CCAAT/enhancer binding proteins (C/EBP) α, β and δ have been shown to be expressed in brain and to be involved in regulation of inflammatory genes in concert with nuclear factor κB (NF-κB). In general, C/EBPα is down-regulated, whereas both C/EBPβ and δ are up-regulated in response to inflammatory stimuli. In Alzheimer's disease (AD) one of the hallmarks is chronic neuroinflammation mediated by astrocytes and microglial cells, most likely induced by the formation of amyloid-β (Aβ) deposits. The inflammatory response in AD has been ascribed both beneficial and detrimental roles. It is therefore important to delineate the inflammatory mediators and signaling pathways affected by Aβ deposits with the aim of defining new therapeutic targets.

Methods

Here we have investigated the effects of Aβ on expression of C/EBP family members with a focus on C/EBPδ in rat primary astro-microglial cultures and in a transgenic mouse model with high levels of fibrillar Aβ deposits (tg-ArcSwe) by western blot analysis. Effects on DNA binding activity were analyzed by electrophoretic mobility shift assay. Cross-talk between C/EBPδ and NF-κB was investigated by analyzing binding to a κB site using a biotin streptavidin-agarose pull-down assay.

Results

We show that exposure to fibril-enriched, but not oligomer-enriched, preparations of Aβ inhibit up-regulation of C/EBPδ expression in interleukin-1β-activated glial cultures. Furthermore, we observed that, in aged transgenic mice, C/EBPα was significantly down-regulated and C/EBPβ was significantly up-regulated. C/EBPδ, on the other hand, was selectively down-regulated in the forebrain, a part of the brain showing high levels of fibrillar Aβ deposits. In contrast, no difference in expression levels of C/EBPδ between wild type and transgenic mice was detected in the relatively spared hindbrain. Finally, we show that interleukin-1β-induced C/EBPδ DNA binding activity to both C/EBP and κB sites is abolished after exposure to Aβ.

Conclusions

These data suggest that both expression and function of C/EBPδ are dysregulated in Alzheimer's disease. C/EBPδ seems to be differently regulated in response to different conformations of Aβ. We propose that Aβ induces an imbalance between NF-κB and C/EBP transcription factors that may result in abnormal responses to inflammatory stimuli.

Cooperation of adenosine with macrophage Toll-4 receptor agonists leads to increased glycolytic flux through the enhanced expression of PFKFB3 gene

Macrophages activated through Toll receptor triggering increase the expression of the A(2A) and A(2B) adenosine receptors. In this study, we show that adenosine receptor activation enhances LPS-induced pfkfb3 expression, resulting in an increase of the key glycolytic allosteric regulator fructose 2,6-bisphosphate and the glycolytic flux. Using shRNA and differential expression of A(2A) and A(2B) receptors, we demonstrate that the A(2A) receptor mediates, in part, the induction of pfkfb3 by LPS, whereas the A(2B) receptor, with lower adenosine affinity, cooperates when high adenosine levels are present. pfkfb3 promoter sequence deletion analysis, site-directed mutagenesis, and inhibition by shRNAs demonstrated that HIF1α is a key transcription factor driving pfkfb3 expression following macrophage activation by LPS, whereas synergic induction of pfkfb3 expression observed with the A(2) receptor agonists seems to depend on Sp1 activity. Furthermore, levels of phospho-AMP kinase also increase, arguing for increased PFKFB3 activity by phosphorylation in long term LPS-activated macrophages. Taken together, our results show that, in macrophages, endogenously generated adenosine cooperates with bacterial components to increase PFKFB3 isozyme activity, resulting in greater fructose 2,6-bisphosphate accumulation. This process enhances the glycolytic flux and favors ATP generation helping to develop and maintain the long term defensive and reparative functions of the macrophages.

Involvement of both intrinsic and extrinsic pathways in hepatoprotection of arjunolic acid against cadmium induced acute damage in vitro

Cadmium (Cd) is one of the ubiquitous environmental pollutants and is responsible for various organ pathophysiology including hepatic disorders. It is extremely toxic even in low concentrations and bioaccumulate in organisms. The present study has been carried out to investigate the cytoprotective role of arjunolic acid (AA), a tri terpenoid saponin, against Cd induced oxidative impairment and cell death in murine hepatocytes. Administration of cadmium (30 μM), in the form of chloride (CdCl(2)) for 2h, significantly enhanced the ALT, ALP and LDH leakage, increased reactive oxygen species (ROS) production, reduced hepatocytes viability and altered the antioxidant status of hepatocytes by reducing intracellular GSH level, anti-oxidant enzymes activity and increasing intracellular GSSG and lipid peroxidation. Evidence for Cd-induced nature of cell death was sought by flow cytometric analysis. Signal transduction studies revealed that Cd markedly increased the levels of caspase-9, -8, -3, Fas and Bid, decreased mitochondrial membrane potential, enhanced cytochrome c release in the cytosol, disturbed the Bcl-2 family protein balance, cleaved PARP protein and ultimately led to apoptotic cell death. Results showed that Cd could trigger both intrinsic and extrinsic apoptotic pathways. In addition, Cd markedly increased NF-κB nuclear translocation in association with IKKα/β phosphorylation and IκBα degradation. Simultaneous treatment with AA (200 μM), however, reduced Cd-induced oxidative stress, attenuated the nuclear translocation of NF-κB and protects the hepatocytes from Cd-induced apoptotic death. Combining, data suggest that Cd-induced hepatic dysfunction and apoptosis might be supported by the ROS formation and mediated via the activation of NF-κB. AA treatment, on the other hand, reduced Cd-induced oxidative stress, attenuated the activation of NF-κB and mitochondrion-dependent and independent apoptotic signaling pathways.

Protective role of a coumarin-derived schiff base scaffold against tertiary butyl hydroperoxide (TBHP)-induced oxidative impairment and cell death via MAPKs, NF-κB and mitochondria-dependent pathways

The present study investigated the antioxidant signalling mechanism of a coumarin-derived schiff base (CSB) scaffold against tert-butylhydroperoxide (TBHP) induced oxidative insult in murine hepatocytes. CSB possesses DPPH and other free radical scavenging activities. TBHP reduced cell viability and intracellular antioxidant status accompanied by an increase in intracellular ROS production in hepatocytes. TBHP also activated phospho-ERK1/2, phospho-p38 and NF-κB, altered the Bcl-2/Bad ratio, reduced mitochondrial membrane potential, released cytochrome C and activated caspase 3, suggesting that TBHP induced oxidative stress responsive cell death via apoptotic pathway. FACS analysis and DNA fragmentation studies also confirmed the apoptotic cell death in TBHP exposed hepatocytes. Treatment with CSB effectively reduced these adverse effects by preventing the oxidative insult, alteration in the redox-sensitive signalling cascades and mitochondrial events. Combining, results suggest that antioxidant property of CSB make the molecule to be a potential protective measure against oxidative insult, cytotoxicity and cell death.

Streptozotocin induced activation of oxidative stress responsive splenic cell signaling pathways: protective role of arjunolic acid

Present study investigates the beneficial role of arjunolic acid (AA) against the alteration in the cytokine levels and simultaneous activation of oxidative stress responsive signaling pathways in spleen under hyperglycemic condition. Diabetes was induced by injection of streptozotocin (STZ) (at a dose of 70 mg/kg body weight, injected in the tail vain). STZ administration elevated the levels of IL-2 as well as IFN-gamma and attenuated the level of TNF-alpha in the sera of diabetic animals. In addition, hyperglycemia is also associated with the increased production of intracellular reactive intermediates resulting with the elevation in lipid peroxidation, protein carbonylation and reduction in intracellular antioxidant defense. Investigating the oxidative stress responsive cell signaling pathways, increased expressions (immunoreactive concentrations) of phosphorylated p65 as well as its inhibitor protein phospho IkappaBalpha and phosphorylated mitogen activated protein kinases (MAPKs) have been observed in diabetic spleen tissue. Studies on isolated splenocytes revealed that hyperglycemia caused disruption of mitochondrial membrane potential, elevation in the concentration of cytosolic cytochrome c as well as activation of caspase 3 leading to apoptotic cell death. Histological examination revealed that diabetic induction depleted the white pulp scoring which is in agreement with the reduced immunological response. Treatment with AA prevented the hyperglycemia and its associated pathogenesis in spleen tissue. Results suggest that AA might act as an anti-diabetic and immunomodulatory agent against hyperglycemia.

C/EBPzeta (CHOP/Gadd153) is a negative regulator of LPS-induced IL-6 expression in B cells

C/EBPzeta was originally identified as a gene induced upon DNA damage and growth arrest. It has been shown to be involved in the cellular response to endoplasmic reticulum stress. Because of sequence divergence from other C/EBP family members in its DNA-binding domain and its consequent inability to bind the C/EBP consensus-binding motif, C/EBPzeta can act as a dominant negative inhibitor of other C/EBPs. C/EBP transactivators are essential to the expression of many proinflammatory cytokines and acute phase proteins, but a role for C/EBPzeta in regulating their expression has not been described. We found that expression of C/EBPzeta is induced in response to LPS treatment of B cells at both the mRNA and protein levels. Correlating with the highest levels of C/EBPzeta expression at 48 h after LPS treatment, there is an increased association of C/EBPzeta with C/EBPbeta, and both the abundance of C/EBP DNA-binding species and IL-6 expression are downregulated. Furthermore, ectopic expression of C/EBPzeta inhibited C/EBPbeta-dependent IL-6 expression from both the endogenous IL-6 gene and an IL-6 promoter-reporter. These results suggest that C/EBPzeta functions as negative regulator of IL-6 expression in B cells and that it contributes to the transitory expression of IL-6 that is observed after LPS treatment.