bay-11-7082 and Inflammation

NLRP3 (Nod-like receptor protein 3) belongs to the NOD-like receptor family, which is activated by pathogen and damage-associated signals to form a multimeric protein complex, known as the NLRP3 inflammasome. NLRP3 inflammasome activation leads to release of proinflammatory cytokines IL-1β and IL-18, thus inducing pyroptosis, a programmed cell death mechanism. Dysregulation of the NLRP3 inflammasome pathway is closely related to the development of many human diseases, such as neuroinflammation, metabolic inflammation, and immune inflammation. Emerging studies have suggested NLRP3 inflammasome as a potential drug-target for inflammatory diseases. Several small molecules have recently been identified to target the NLRP3 inflammasome pathway directly or indirectly and alleviate related disease pathology. This review summarizes recent evolving landscape of small molecule inhibitor development targeting the NLRP3 inflammasome pathway.

Topics: Humans; Inflammasomes; Inflammation; Molecular Structure; NLR Family, Pyrin Domain-Containing 3 Protein; Small Molecule Libraries; Structure-Activity Relationship

The blockage of transient receptor potential vanilloid 4 (TRPV4) inhibits inflammation and reduces hippocampal neuronal injury in a pilocarpine-induced mouse model of temporal lobe epilepsy. However, the underlying mechanisms remain largely unclear. NF-κB signaling pathway is responsible for the inflammation and neuronal injury during epilepsy. Here, we explored whether TRPV4 blockage could affect the NF-κB pathway in mice with pilocarpine-induced status epilepticus (PISE). Application of a TRPV4 antagonist markedly attenuated the PISE-induced increase in hippocampal HMGB1, TLR4, phospho (p)-IκK (p-IκK), and p-IκBα protein levels, as well as those of cytoplasmic p-NF-κB p65 (p-p65) and nuclear NF-κB p65 and p50; in contrast, the application of GSK1016790A, a TRPV4 agonist, showed similar changes to PISE mice. Administration of the TLR4 antagonist TAK-242 or the NF-κB pathway inhibitor BAY 11-7082 led to a noticeable reduction in the hippocampal protein levels of cleaved IL-1β, IL-6 and TNF, as well as those of cytoplasmic p-p65 and nuclear p65 and p50 in GSK1016790A-injected mice. Finally, administration of either TAK-242 or BAY 11-7082 greatly increased neuronal survival in hippocampal CA1 and CA2/3 regions in GSK1016790A-injected mice. Therefore, TRPV4 activation increases HMGB1 and TLR4 expression, leading to IκK and IκBα phosphorylation and, consequently, NF-κB activation and nuclear translocation. The resulting increase in pro-inflammatory cytokine production is responsible for TRPV4 activation-induced neuronal injury. We conclude that blocking TRPV4 can downregulate HMGB1/TLR4/IκK/κBα/NF-κB signaling following PISE onset, an effect that may underlie the anti-inflammatory response and neuroprotective ability of TRPV4 blockage in mice with PISE.

Topics: Animals; Antineoplastic Agents; HMGB1 Protein; Inflammation; Mice; NF-kappa B; NF-KappaB Inhibitor alpha; Pilocarpine; Signal Transduction; Status Epilepticus; Toll-Like Receptor 4; TRPV Cation Channels

Age-related hearing loss (ARHL) is a common issue associated with aging. One of the typical causes of hearing loss is the damage to inner ear hair cells. In addition, oxidative stress and inflammation contribute to ARHL. To avoid excessive inflammatory responses, non-classical scorch death pathway by cell membrane lipopolysaccharide (LPS) activates of caspase-11. Piceatannol (PCT) is also known for anti-tumor, antioxidant and anti-inflammatory effects; however, the protective effect of piceatannol (PCT) on ARHL is unclear. The aim of this study was to elucidate the mechanism underlying protective effect of PCT on ARHL-induced inner ear hair cell damage. In vivo experiments showed that PCT could protect mice from inflammatory aging-induced hearing loss as well as from inner hair cells (IHC) and spiral ganglion (SG) deficits. In addition, inflammatory vesicle inhibitor BAY11-7082 ameliorated ARHL, inhibited NLRP3 and reduced GSDMD expression. In in vitro experiments we used LPS and D-gal to simulate the aging inflammatory environment. The results showed that intracellular reactive oxygen species levels, expression of Caspase-11, NLRP3, and GSDMD were significantly increased, yet treatment with PCT or BAY11-7082 significantly improved HEI-OC-1 cell injury while reducing inflammation-associated protein expression as well as the occurrence of pyroptosis. In conclusion, these results suggest a protective role for PCT against ARHL, possibly through Caspase-11-GSDMD pathway. Our findings may provide a new target and theoretical basis for hearing loss treatment using PCT.

Topics: Animals; Caspases; Inflammation; Lipopolysaccharides; Mice; NLR Family, Pyrin Domain-Containing 3 Protein; Presbycusis; Pyroptosis

Periodontitis is a chronic osteolytic inflammatory disease resulting from complex dynamic interactions among bacterial pathogens and the host immune response. Macrophages play a vital role in the pathogenesis of periodontitis by triggering periodontal inflammation and inducing periodontium destruction. N-Acetyltransferase 10 (NAT10) is an acetyltransferase that has been shown to catalyse N4-acetylcytidine (ac4C) mRNA modification and is related to cellular pathophysiological processes, including the inflammatory immune response. Nevertheless, whether NAT10 regulates the inflammatory response of macrophages in periodontitis remains unclear. In this study, the expression of NAT10 in macrophages was found to decrease during LPS-induced inflammation. NAT10 knockdown significantly reduced the generation of inflammatory factors, while NAT10 overexpression had the opposite effect. RNA sequencing revealed that the differentially expressed genes were enriched in the NF-κB signalling pathway and oxidative stress. Both the NF-κB inhibitor Bay11-7082 and the ROS scavenger N-acetyl-L-cysteine (NAC) could reverse the upregulation of inflammatory factors. NAC inhibited the phosphorylation of NF-κB, but Bay11-7082 had no effect on the production of ROS in NAT10-overexpressing cells, suggesting that NAT10 activated the LPS-induced NF-κB signalling pathway by regulating ROS generation. Furthermore, the expression and stability of Nox2 was promoted after NAT10 overexpression, indicating that Nox2 may be a potential target of NAT10. In vivo, the NAT10 inhibitor Remodelin reduced macrophage infiltration and bone resorption in ligature-induced periodontitis mice. In summary, these results showed that NAT10 accelerated LPS-induced inflammation via the NOX2-ROS-NF-κB pathway in macrophages and that its inhibitor Remodelin might be of potential therapeutic significance in periodontitis treatment.

Topics: Animals; Inflammation; Lipopolysaccharides; Macrophages; Mice; NADPH Oxidase 2; NF-kappa B; Periodontitis; Reactive Oxygen Species

Oxygen homeostasis disturbances play a critical role in the pathogenesis of acute kidney injury (AKI). The transcription factor hypoxia-inducible factor-1 (HIF-1) is a master regulator of adaptive responses to hypoxia. Aside from posttranslational hydroxylation, the mechanism of HIF-1 regulation in AKI remains largely unclear. In this study, the mechanism of HIF-α regulation in AKI was investigated. We found that tubular HIF-1α expression significantly increased at the transcriptional level in ischemia-reperfusion-, unilateral ureteral obstruction-, and sepsis-induced AKI models, which was closely associated with macrophage-dependent inflammation. Meanwhile, NF-κB, which plays a central role in the inflammation response, was involved in the increasing expression of HIF-1α in AKI, as evidenced by pharmacological modulation (NF-κB inhibitor BAY11-7082). Mechanistically, NF-κB directly bound to the HIF-1α promoter and enhanced its transcription, which occurred not only under hypoxic conditions but also under normoxic conditions. Moreover, the induced HIF-1α by inflammation protected against tubular injury in AKI. Thus, our findings not only provide novel insights into HIF-1 regulation in AKI but also offer to understand the pathophysiology of kidney diseases.

Topics: Acute Kidney Injury; Animals; Cells, Cultured; Epithelial Cells; Gene Expression Regulation; Hypoxia-Inducible Factor 1, alpha Subunit; Inflammation; Kidney; Mice; NF-kappa B; Nitriles; Sulfones

It has been widely accepted that long-noncoding RNA (lncRNA) HOX transcript antisense intergenic RNA (HOTAIR) emerges as a crucial mediator in inflammation. Here, we first detected HOTAIR in lipopolysaccharide (LPS)-treated normal human liver cell line (L02) and hepatocellular carcinoma cell lines (C3A, HepG2, and SMMC-7721). Further, we explored the biological function of HOTAIR in LPS-induced hepatocytes (L02 and C3A) lesions and investigated the molecular mechanisms. Besides, we focused on inflammatory signaling crosstalk. The inflammatory insults were assayed by cell counting kit-8 (CCK-8), cell cycle and apoptosis analysis kit, and immunoblotting assay. HOTAIR level was examined by reverse-transcription polymerase chain reaction. To determine the effect of HOTAIR silence or overexpression in inflammation, we applied quantitative reverse-transcription polymerase chain reaction, immunoblotting assay, and enzyme-linked immuno sorbent assay. Regulator inhibitors of Janus kinase/signal transducer and activator of transcription (JAK2/STAT3; AG490) and nuclear factor κB (NF-κB; BAY-11-7082) were applied to treat cells. Our results suggested that LPS induced the overexpression of HOTAIR in L02, C3A, HepG2, and SMMC-7721 cells. LPS repressed viability, induced apoptosis, and facilitated the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in L02 and C3A cells. IL-1β, IL-6, and TNF-α were upregulated by HOTAIR overexpression while downregulated by HOTAIR knockdown in LPS-treated cells. We further observed that HOTAIR overexpression accelerated LPS-induced phosphorylation whereas HOTAIR silence blocked this progress. Inhibition of JAK/STAT and NF-κB contributed to the suppression of cytokines which was evoked by LPS. Collectively, our findings indicated that HOTAIR exerted a crucial role in cytokines expression by activating JAK/STAT and NF-κB.

Topics: Apoptosis; Cell Line; Cell Survival; Cytokines; Gene Expression Regulation; Hepatocytes; Humans; Inflammation; Janus Kinases; Lipopolysaccharides; NF-kappa B; Nitriles; RNA, Long Noncoding; STAT Transcription Factors; Sulfones

BACKGROUND Acute pancreatitis (AP) is a symptom of sudden pancreas inflammation, which causes patients severe suffering. In general, fibroblast growth factor (FGF) levels are increased and amylase and lipase activities are elevated during AP pathogenesis, but protein concentration are low. However, the mechanism through which FGF signaling regulates AP pathogenesis remains elusive. MATERIAL AND METHODS The concentrations of PGE2, TNF-alpha, sCRP, FGF1, and FGF2 in the serum samples of the AP group and healthy control group were detected by enzyme-linked immunosorbent assay. In addition, IkappaBalpha and p-IkappaBalpha levels were analyzed in the serum samples. Subsequently, the AP rat model was established, and FGF1, FGF2, anti-FGF1, and anti-FGF2 antibodies and Bay11-7082 were injected into AP rats. TNF-alpha, PAI-1 JNK, p-JNK, IkappaBalpha, and p-IkappaBalpha levels were also examined. RESULTS Results showed that levels of PGE2, TNF-alpha, sCRP, p-IkappaBalpha, FGF1, and FGF2, as well as amylase and lipase activity were increased in patients with AP compared with those in healthy people. In addition, protein concentrations were lower in patients with AP than in the healthy group. Activation of FGF signaling by injecting FGF1 or FGF2 also inhibited AP-induced inflammation response in the pancreas and increased amylase and lipase activities, as well as protein concentration. However, the injection of FGF1 and FGF2 antibodies accelerated AP-mediated inflammation responses in the serum. In addition, Bay11-7082 injection inhibited AP activation of inflammation response and amylase and lipase activities. Protein concentration were also increased in AP rats. CONCLUSIONS FGF signaling protects against AP-mediated damage by inhibition of AP-activating inflammatory responses.

Topics: Acute Disease; Adult; Amylases; Animals; C-Reactive Protein; Case-Control Studies; Dinoprostone; Female; Fibroblast Growth Factor 1; Fibroblast Growth Factor 2; Humans; Inflammation; Lipase; Male; Middle Aged; NF-KappaB Inhibitor alpha; Nitriles; Pancreatitis; Rats; Rats, Sprague-Dawley; Signal Transduction; Sulfones; Tumor Necrosis Factor-alpha

Innate immune activation contributes to the transition from nonalcoholic fatty liver to nonalcoholic steatohepatitis (NASH). Stimulator of IFN genes (STING, also referred to Tmem173) is a universal receptor that recognizes released DNA and triggers innate immune activation. In this work, we investigated the role of STING in the progression of NASH in mice. Both methionine- and choline-deficient diet (MCD) and high-fat diet (HFD) were used to induce NASH in mice. Strikingly, STING deficiency attenuated steatosis, fibrosis, and inflammation in livers in both murine models of NASH. Additionally, STING deficiency increased fasting glucose levels in mice independently of insulin, but mitigated HFD-induced insulin resistance and weight gain and reduced levels of cholesterol, triglycerides, and LDL in serum; it also enhanced levels of HDL. The mitochondrial DNA (mtDNA) from hepatocytes of HFD-fed mice induced TNF-α and IL-6 expression in cultured Kupffer cells (KCs), which was attenuated by STING deficiency or pretreatment with BAY11-7082 (an NF-κB inhibitor). Finally, chronic exposure to 5,6-dimethylxanthenone-4-acetic acid (DMXAA, a STING agonist) led to hepatic steatosis and inflammation in WT mice, but not in STING-deficient mice. We proposed that STING functions as an mtDNA sensor in the KCs of liver under lipid overload and induces NF-κB-dependent inflammation in NASH.

Topics: Animals; Dietary Fats; DNA, Mitochondrial; Female; Hepatocytes; Humans; Inflammation; Insulin Resistance; Interleukin-6; Kupffer Cells; Membrane Proteins; Mice; Mice, Mutant Strains; Mitochondria, Liver; Nitriles; Non-alcoholic Fatty Liver Disease; Oxygen Consumption; Sulfones; Tumor Necrosis Factor-alpha; Xanthones

Topics: Animals; Ethanol; Gene Expression Regulation; Humans; Inflammation; Interleukin-1beta; Interleukin-6; Lipopolysaccharides; Macrophages; Mice; NF-kappa B; Nitric Oxide; Nitriles; Plant Extracts; RAW 264.7 Cells; Stramenopiles; Sulfones

Hemozoin produced by Plasmodium falciparum during malaria infection has been linked to the neurological dysfunction in cerebral malaria. In this study, we determined whether a synthetic form of hemozoin (sHZ) produces neuroinflammation and neurotoxicity in cellular models. Incubation of BV-2 microglia with sHZ (200 and 400 µg/ml) induced significant elevation in the levels of TNFα, IL-6, IL-1β, NO/iNOS, phospho-p65, accompanied by an increase in DNA binding of NF-κB. Treatment of BV-2 microglia with sHZ increased protein levels of NLRP3 with accompanying increase in caspase-1 activity. In the presence of NF-κB inhibitor BAY11-7082 (10 µM), there was attenuation of sHZ-induced release of pro-inflammatory cytokines, NO/iNOS. In addition, increase in caspase-1/NLRP3 inflammasome activation was blocked by BAY11-7082. Pre-treatment with BAY11-7082 also reduced both phosphorylation and DNA binding of the p65 sub-unit. The NLRP3 inhibitor CRID3 (100 µM) did not prevent sHZ-induced release of TNFα and IL-6. However, production of IL-1β, NO/iNOS as well as caspase-1/NLRP3 activity was significantly reduced in the presence of CRID3. Incubation of differentiated neural progenitor (ReNcell VM) cells with sHZ resulted in a reduction in cell viability, accompanied by significant generation of cellular ROS and increased activity of caspase-6, while sHZ-induced neurotoxicity was prevented by N-acetylcysteine and Z-VEID-FMK. Taken together, this study shows that the synthetic form of hemozoin induces neuroinflammation through the activation of NF-κB and NLRP3 inflammasome. It is also proposed that sHZ induces ROS- and caspase-6-mediated neurotoxicity. These results have thrown more light on the actions of malarial hemozoin in the neurobiology of cerebral malaria.

Topics: Animals; Caspase 1; Caspase 6; Cell Differentiation; Cell Line; Cell Survival; Cytokines; DNA; Hemeproteins; Humans; Inflammation; Inflammation Mediators; Mice; Neurons; Neurotoxicity Syndromes; Nitric Oxide Synthase Type II; Nitriles; Nitrites; NLR Family, Pyrin Domain-Containing 3 Protein; Protein Binding; Reactive Oxygen Species; Sulfones; Transcription Factor RelA

Sanguisorba officinalis L. was well known as a traditional herbal medicine to treat inflammation and allergic skin diseases. The aim of this research was to indentify compounds with anti-allergic inflammatory property. Twenty-five compounds (1-25) were isolated from S. officinalis including two new compounds (1 and 8), and their chemical structures were identified by NMR and ESIMS analysis. Consequently, the anti-allergic inflammatory activities of these isolates were investigated by inhibiting β-hexosaminidase and IL-4 production in PMA/A23187-stimulated RBL-2H3 cells. Compounds 6, 8, 13, 17-18 and 25 significantly inhibited β-hexosaminidase release and IL-4 production. Additionally, compounds 8, 17 and 25 effectively suppressed the activation of NF-κB and NF-κB p65 translocation into the nucleus. Anti-inflammatory effects of isolated compounds were evaluated in LPS-stimulated RAW264.7 macrophages, and they showed dramatic inhibition on LPS-induced overproduction of nitric oxide (NO) and TNF-α. Consistently, the protein levels of iNOS and COX-2 were remarkably decreased by the single compounds 8, 13 and 25. These results showed that compounds 8, 13 and 25 from S. officinalis may have a therapeutic potential for allergic inflammatory diseases.

Topics: Animals; Anti-Allergic Agents; beta-N-Acetylhexosaminidases; Dose-Response Relationship, Drug; Enzyme Inhibitors; Inflammation; Interleukin-4; Lipopolysaccharides; Macrophages; Mice; Molecular Structure; Nitric Oxide; Rats; RAW 264.7 Cells; Sanguisorba; Structure-Activity Relationship; Tetradecanoylphorbol Acetate; Tumor Necrosis Factor-alpha

Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, has been demonstrated to have potent anti-inflammatory properties. However, the protective effects of STS on lipopolysaccharide (LPS)-induced inflammation in endothelial cells remain to be elucidated. In the present study, human umbilical vein endothelial cells (HUVECs) were used to explore the effects of STS on LPS-induced inflammation and the molecular mechanism involved. HUVECs were pretreated with STS for 2 h, followed by stimulation with LPS. Then expression and secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and the activation of nuclear factor-κB (NF-κB) were assessed. The results demonstrated that STS significantly decreased LPS-induced TNF-α and IL-1β protein expression in HUVECs. Similarly, the increased levels of TNF-α and IL-1β in cell supernatants stimulated by LPS were also significantly inhibited by STS. Furthermore, STS inhibited LPS-induced NF-κB p65 phosphorylation and nuclear translocation. All the results suggest that STS prevents LPS-induced inflammation through suppressing NF-κB signaling pathway in endothelial cells, indicating the potential utility of STS for the treatment of inflammatory diseases.

Topics: Cell Survival; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Interleukin-1beta; Lipopolysaccharides; NF-kappa B; Nitriles; Phenanthrenes; Signal Transduction; Sulfones; Tumor Necrosis Factor-alpha

Aberrant activation of the transcription factor NF-

Topics: Benzamides; Cell Line; Escherichia coli; Flow Cytometry; Gene Expression Regulation; Humans; Immunohistochemistry; Inflammation; NF-kappa B; Nitriles; Salmonella; Sulfones

Macrophage-mediated inflammation has been implicated in various kidney diseases. We previously reported that Rac1, a Rho family small GTP-binding protein, was overactivated in several chronic kidney disease models, and that Rac1 inhibitors ameliorated renal injury, in part via inhibition of inflammation, but the detailed mechanisms have not been clarified. In the present study, we examined whether Rac1 in macrophages effects cytokine production and the inflammatory mechanisms contributing to kidney derangement. Myeloid-selective Rac1 flox control (M-Rac1 FC) and knockout (M-Rac1 KO) mice were generated using the cre-loxP system. Renal function under basal conditions did not differ between M-Rac1 FC and KO mice. Accordingly, lipopolysaccharide (LPS)-evoked kidney injury model was created. LPS elevated blood urea nitrogen and serum creatinine, enhanced expressions of kidney injury biomarkers, Kim-1 and Ngal, and promoted tubular injury in M-Rac1 FC mice. By contrast, deletion of myeloid Rac1 almost completely prevented the LPS-mediated renal impairment. LPS triggered a marked induction of macrophage-derived inflammatory cytokines, IL-6 and TNFα, in M-Rac1 FC mice, which was accompanied by Rac1 activation, stimulation of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, and reactive oxygen species overproduction. These changes were inhibited in M-Rac1 KO mice. LPS evoked F4/80-positive macrophages accumulation in the kidney, which was not affected by myeloid Rac1 deficiency. We further tested the role of Rac1 signaling in cytokine production using macrophage cell line, RAW264.7. Exposure to LPS increased IL-6 and TNFα mRNA expression. The LPS-driven cytokine induction was dose-dependently blocked by the Rac1 inhibitor EHT1864, NADPH oxidase inhibitor diphenyleneiodonium, and NF-κB inhibitor BAY11-7082. In conclusion, genetic ablation of Rac1 in the myeloid lineage protected against LPS-induced renal inflammation and injury, by suppressing macrophage-derived cytokines, IL-6 and TNFα, without blocking recruitment. Our data suggest that Rac1 in macrophage is a novel target for the treatment of kidney disease through inhibition of cytokine production.

Topics: Animals; Biomarkers; Cell Line; Cell Lineage; Chemokine CCL2; Chemokine CXCL1; Chemokine CXCL2; Culture Media, Conditioned; Cytokines; Gene Deletion; Gene Expression Regulation; Inflammation; Interleukin-6; Kidney; Lipopolysaccharides; Macrophages; Male; Mice; Mice, Knockout; Monocytes; Myeloid Cells; NADPH Oxidases; Neuropeptides; Nitriles; Onium Compounds; Pyrones; Quinolines; rac1 GTP-Binding Protein; Reactive Oxygen Species; Sulfones; Tumor Necrosis Factor-alpha

Lagerstroemia ovalifolia Teijsm. & Binn. has traditionally been used as an herbal medicine and possesses anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory effects remain poorly understood. For this purpose, we aimed to investigate the effects of methanolic extract of L. ovalifolia (LOME) on nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the underlying molecular mechanisms responsible for these effects, in lipopolysaccharide (LPS)‑stimulated RAW264.7 macrophages. We examined the effects of LOME on the production of NO and PGE2 in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of LOME, we measured the mRNA or protein expression of the pro‑inflammatory mediators induced by LOME in the LPS-stimulated RAW264.7 cells. LOME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW264.7 cells. Moreover, LOME suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs), with a reduction in the nuclear translocation of nuclear factor (NF)-κB in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that LOME may exert anti-inflammatory effects in vitro in LPS-stimulated RAW264.7 macrophages and thus, may have potential for use as an adjuvant treatment of inflammatory diseases.

Topics: Animals; Cell Death; Cell Nucleus; Cell Survival; Cyclooxygenase 2; Cytokines; Dinoprostone; Enzyme Activation; Inflammation; Inflammation Mediators; Lagerstroemia; Lipopolysaccharides; Macrophages; Methanol; Mice; Mitogen-Activated Protein Kinases; NF-kappa B; NF-KappaB Inhibitor alpha; Nitric Oxide; Nitric Oxide Synthase Type II; Nitriles; Phosphorylation; Plant Extracts; Protein Transport; RAW 264.7 Cells; Sulfones; Transcription, Genetic

We aim at determining the changes in the expression of NF-kB signaling pathway in degenerative intervertebral discs. We collected normal and degenerated intervertebral discs tissues. The normal and degenerated cells were cultivated and their histopathology and immunofluoresence studies were used to observe the position of NF-kB p65 in the cell. We also treated the nucleus pulposus cells with inflammatory factors and inhibitors. Western blot was used to analyze the expression of different proteins. Real time fluorescence-based quantitative PCR was used for observation of NF-kB regulation of change in gene expression. Immunofluorescence showed that in the non-degenerative group the p65 was found in the cytoplasm of the nucleus pulposus cell while in the degenerated cell group the p65 protein was found in the nucleus of the cell. The expression of p65 increased with increase in the degree of degenerative change of the nucleus pulposus cell. RT-PCR showed that the expression of matrix metalloproteinases, aggrecanases and IL-6 was higher in the degenerative group. The amount of aggrecan and type II collagen was significantly decreased in the degenerative group. IL-1β was able to upregulate the activation of NF-kB and the expression of MMP-13 and ADAMTS-4 was also significantly increased. The effect of these proteins can be inhibited by the NF-kB inhibitor, BAY11-7082. The activation of the NK-kB signaling pathway in a degenerative intervertebral disc is gradually increased, regulating the over-expression of matrix-degrading enzymes. It plays an important role in the degradation of extracellular matrix.

Topics: ADAMTS4 Protein; Adolescent; Adult; Aged; Collagen Type II; Extracellular Matrix; Humans; Inflammation; Interleukin-1beta; Interleukin-6; Intervertebral Disc; Intervertebral Disc Degeneration; Low Back Pain; Matrix Metalloproteinase 13; Microscopy, Fluorescence; Middle Aged; Nitriles; Nucleus Pulposus; Real-Time Polymerase Chain Reaction; Signal Transduction; Sulfones; Transcription Factor RelA; Young Adult

Catalase is an antioxidant enzyme that specifically catabolizes hydrogen peroxide (H2O2). Overexpression of catalase via a heart-specific promoter (CAT-TG) was reported to reduce diabetes-induced accumulation of reactive oxygen species (ROS) and further prevent diabetes-induced pathological abnormalities, including cardiac structural derangement and left ventricular abnormity in mice. However, the mechanism by which catalase overexpression protects heart function remains unclear. This study found that activation of a ROS-dependent NF-κB signaling pathway was downregulated in hearts of diabetic mice overexpressing catalase. In addition, catalase overexpression inhibited the significant increase in nitration levels of key enzymes involved in energy metabolism, including α-oxoglutarate dehydrogenase E1 component (α-KGD) and ATP synthase α and β subunits (ATP-α and ATP-β). To assess the effects of the NF-κB pathway activation on heart function, Bay11-7082, an inhibitor of the NF-κB signaling pathway, was injected into diabetic mice, protecting mice against the development of cardiac damage and increased nitrative modifications of key enzymes involved in energy metabolism. In conclusion, these findings demonstrated that catalase protects mouse hearts against diabetic cardiomyopathy, partially by suppressing NF-κB-dependent inflammatory responses and associated protein nitration.

Topics: Animals; Apoptosis; Cardiotonic Agents; Catalase; Cell Line; Diabetes Mellitus, Experimental; Inflammation; Mice, Transgenic; Myocardium; NF-kappa B; Nitriles; Nitrosation; Organ Specificity; Reactive Nitrogen Species; Reactive Oxygen Species; Signal Transduction; Sulfones; Tyrosine

Phellinus linteus (Berkeley & Curtis), a well-known medical fungus, has long been used as a traditional medicine in Oriental countries to treat various diseases, and hispolon (HIS) is one of its bioactive components. HIS is known to possess potent antineoplastic and antiviral properties; however, its effect on inflammatory apoptosis is still undefined.. RAW264.7 macrophages were incubated with HIS for 30 min followed by LPS, LTA, or PGN stimulation for 12h. The expression of indicated proteins AP-1 and NF-κB transcriptional activities was examined by Western blotting using specific antibodies. Levels of NO and ROS were examined by Griess reaction, and DCHF-DA staining via flow cytometric analysis, respectively. AP-1 and NF-κB transcriptional activities were detected by luciferase reporter assay. Knockdown of HO-1 protein expression was performed by transfection of macrophages with HO-1 siRNA. Pharmacological inhibitors including ROS scavenger NAC, JNK inhibitor SP600125, NF-κB inhibitor BAY117082 were applied for mechanism study.. HIS showed concentration-dependent inhibition of LPS, LTA, and PGN-induced iNOS protein expressions and NO production by RAW264.7 macrophages. Accordingly, HIS protected RAW264.7 cells from LPS-, LTA-, and PGN-induced apoptosis. Increased HO-1 by HIS was detected at both protein and mRNA levels along with an increase in intracellular peroxide, and this was inhibited by the translational inhibitor, cycloheximide (CHX), the transcriptional inhibitor, actinomycin D (Act D), and the reactive oxygen species scavenger, N-acetylcysteine (NAC). A mechanistic study indicated that inhibition of c-Jun N-terminal kinase (JNK) protein phosphorylation, and activator protein (AP)-1 and nuclear factor (NF)-κB activation were involved in the anti-inflammatory actions of HIS in macrophages. A structure-activity relationship analysis showed that HIS expressed the most potent effect of inhibiting iNOS and apoptosis elicited by LPS, LTA, and PGN with a significant increase in HO-1 protein in macrophages.. Evidence supporting HIS prevention of inflammatory apoptosis via blocking NO production and inducing HO-1 protein expression in macrophages is provided, and the hydroxyl at position C3 is a critical substitution for the anti-inflammatory actions of HIS.

Topics: Anthracenes; Apoptosis; Catechols; Dose-Response Relationship, Drug; Heme Oxygenase-1; Inflammation; Lipopolysaccharides; Macrophages; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Nitriles; Reactive Oxygen Species; RNA, Small Interfering; Structure-Activity Relationship; Sulfones; Teichoic Acids; Transcription Factor AP-1

We and others have recently shown that soyasaponins abundant in soybeans can decrease inflammation by suppressing the nuclear factor kappa B (NF-kB)-mediated inflammation. However, the exact molecular mechanisms by which soyasaponins inhibit the NF-kB pathway have not been established. In this study in macrophages, soyasaponins (A1, A2 and I) inhibited the lipopolysaccharide (LPS)-induced release of inflammatory marker prostaglandin E2 (PGE2) to a similar extent as the NF-kB inhibitor (BAY117082). Soyasaponins (A1, A2 and I) also suppressed the LPS-induced expression of cyclooxygenase 2 (COX-2), another inflammatory marker, in a dose-dependent manner by inhibiting NF-kB activation. In defining the associated mechanisms, we found that soyasaponins (A1, A2 and I) blunted the LPS-induced IKKα/β phosphorylation, IkB phosphorylation and degradation, and NF-kB p65 phosphorylation and nuclear translocation. In studying the upstream targets of soyasaponins on the NF-kB pathway, we found that soyasaponins (A1, A2 and I) suppressed the LPS-induced activation of PI3K/Akt similarly as the PI3K inhibitor LY294002, which alone blocked the LPS-induced activation of NF-kB. Additionally, soyasaponins (A1, A2 and I) reduced the LPS-induced production of reactive oxygen species (ROS) to the same extent as the anti-oxidant N-acetyl-L-cysteine, which alone inhibited the LPS-induced phosphorylation of Akt, IKKα/β, IkBα, and p65, transactivity of NF-kB, PGE2 production, and malondialdehyde production. Finally, our results show that soyasaponins (A1, A2 and I) elevated SOD activity and the GSH/GSSG ratio. Together, these results show that soyasaponins (A1, A2 and I) can blunt inflammation by inhibiting the ROS-mediated activation of the PI3K/Akt/NF-kB pathway.

Topics: Animals; Cell Line; Chromones; Cyclooxygenase 2; Dinoprostone; Glycine max; I-kappa B Kinase; Inflammation; Lipopolysaccharides; Macrophages; Malondialdehyde; Mice; Morpholines; Nitriles; Oleanolic Acid; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Saponins; Signal Transduction; Sulfones; Superoxide Dismutase; Transcription Factor RelA

Inflammation can influence multipotency and self-renewal of mesenchymal stem cells (MSCs), resulting in their awakened bone-regeneration ability. Human periodontal ligament tissue-derived MSCs (PDLSCs) have been isolated, and their differentiation potential was found to be defective due to β-catenin signaling indirectly regulated by inflammatory microenvironments. Nuclear factor-κB (NF-κB) is well studied in inflammation by many different groups. The role of NF-κB needs to be studied in PDLSCs, although genetic evidences have recently shown that NF-κB inhibits osteoblastic bone formation in mice. However, the mechanism as to how inflammation leads to the modulation of β-catenin and NF-κB signaling remains unclear. In this study, we investigated β-catenin and NF-κB signaling through regulation of glycogen synthase kinase 3β activity (GSK-3β, which modulates β-catenin and NF-κB signaling) using a specific inhibitor LiCl and a phosphatidylinositol 3-kinase (PI3K) inhibitor LY 294002. We identified that NF-κB signaling might be more important for the regulation of osteogenesis in PDLSCs from periodontitis compared with β-catenin. BAY 11-7082 (an inhibitor of NF-κB) could inhibit phosphorylation of p65 and partly rescue the differentiation potential of PDLSCs in inflammation. Our data indicate that NF-κB has a central role in regulating osteogenic differentiation of PDLSCs in inflammatory microenvironments. Given the molecular mechanisms of NF-κB in osteogenic differentiation governed by inflammation, it can be said that NF-κB helps in improving stem cell-mediated inflammatory bone disease therapy.

Topics: Adult; Animals; beta Catenin; Cell Differentiation; Cells, Cultured; Cellular Microenvironment; Chromones; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Inflammation; Lithium Chloride; Mesenchymal Stem Cells; Mice; Morpholines; NF-kappa B; Nitriles; Osteogenesis; Periodontal Ligament; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; RNA, Messenger; Signal Transduction; Sulfones; Transcription Factor RelA; Wnt Signaling Pathway

Neuroinflammation is a common feature of acute neurological conditions such as stroke and spinal cord injury, as well as neurodegenerative conditions such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. Previous studies have demonstrated that acute neuroinflammation can adversely affect the survival of neural precursor cells (NPCs) and thereby limit the capacity for regeneration and repair. However, the mechanisms by which neuroinflammatory processes induce NPC death remain unclear. Microglia are key mediators of neuroinflammation and when activated to induce a pro-inflammatory state produce a number of factors that could affect NPC survival. Importantly, in the present study we demonstrate that tumor necrosis factor α (TNFα) produced by lipopolysaccharide-activated microglia is necessary and sufficient to trigger apoptosis in mouse NPCs in vitro. Furthermore, we demonstrate that microglia-derived TNFα induces NPC apoptosis via a mitochondrial pathway regulated by the Bcl-2 family protein Bax. BH3-only proteins are known to play a key role in regulating Bax activation and we demonstrate that microglia-derived TNFα induces the expression of the BH3-only family member Puma in NPCs via an NF-κB-dependent mechanism. Specifically, we show that NF-κB is activated in NPCs treated with conditioned media from activated microglia and that Puma induction and NPC apoptosis is blocked by the NF-κB inhibitor BAY-117082. Importantly, we have determined that NPC apoptosis induced by activated microglia-derived TNFα is attenuated in Puma-deficient NPCs, indicating that Puma induction is required for NPC death. Consistent with this, we demonstrate that Puma-deficient NPCs exhibit an ∼13-fold increase in survival as compared with wild-type NPCs following transplantation into the inflammatory environment of the injured spinal cord in vivo. In summary, we have identified a key signaling pathway that regulates neuroinflammation induced apoptosis in NPCs in vitro and in vivo that could be targeted to promote regeneration and repair in diverse neurological conditions.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Culture Media, Conditioned; Inflammation; Lipopolysaccharides; Mice; Mice, Knockout; Microglia; Mitochondria; Neural Stem Cells; NF-kappa B; Nitriles; Signal Transduction; Spinal Cord; Spinal Cord Injuries; Sulfones; Transcriptional Activation; Tumor Necrosis Factor-alpha; Tumor Suppressor Proteins

Interleukin (IL) 33, a member of IL-1 cytokine family, is well known to promote Th2 type immune responses by signaling through its receptor ST2. However, it is not clear whether ST2 is expressed by mucosal epithelium, and how it responds to IL-33 to induce inflammatory mediators. This study was to identify the presence and function of ST2 and explore the role of IL-33/ST2 signaling in regulating the inflammatory cytokine production in corneal epithelial cells. Human corneal tissues and cultured primary human corneal epithelial cells (HCECs) were treated with IL-33 in different concentrations without or with different inhibitors to evaluate the expression, location and signaling pathways of ST2 in regulating production of inflammatory cytokine and chemokine. The mRNA expression was determined by reverse transcription and real time PCR, and protein production was measured by enzyme-linked immunosorbent assay (ELISA), immunohistochemical and immunofluorescent staining. ST2 mRNA and protein were detected in donor corneal epithelium and cultured HCECs, and ST2 signal was enhanced by exposure to IL-33. IL-33 significantly stimulated the production of inflammatory cytokines (TNF-α, IL-1β and IL-6) and chemokine IL-8 by HCECs at both mRNA and protein levels. The stimulated production of inflammatory mediators by IL-33 was blocked by ST2 antibody or soluble ST2 protein. Interestingly, the IκB-α inhibitor BAY11-7082 or NF-κB activation inhibitor quinazoline blocked NF-κB p65 protein phosphorylation and nuclear translocation, and also suppressed the production of these inflammatory cytokines and chemokine induced by IL-33. These findings demonstrate that ST2 is present in human corneal epithelial cells, and IL-33/ST2 signaling plays an important role in regulating IL-33 induced inflammatory responses in ocular surface.

Topics: Adult; Aged; Antibodies, Neutralizing; Cytokines; Epithelial Cells; Epithelium, Corneal; Gene Expression Regulation; Humans; Inflammation; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Interleukins; Middle Aged; NF-kappa B; Nitriles; Primary Cell Culture; Quinazolines; Receptors, Cell Surface; RNA, Messenger; Signal Transduction; Sulfones

Nuclear factor-kappa B (NF-κB) and NLRP3 inflammasome are involved in inflammation and autoimmunity. In vitro data have shown that Bay11-7082 selectively inhibits NLRP3 inflammasome activity independent of NF-κB activity. In this study, we evaluated the therapeutic effects of Bay11-7082 on murine lupus nephritis (LN) in vivo. Twelve-week-old MRL/lpr mice were treated with either Bay11-7082 (5mg/kg) or vehicle (DMSO/PBS buffer) by intraperitoneal injection thrice per week for 8 weeks. NLRP3 inflammasome formation and NF-κB activation were measured. Histopathology, immune complex deposits, proteinuria, renal function and production of anti-dsDNA antibody as well as inflammatory markers were evaluated. Bay11-7082 treatment inhibited renal NLRP3 inflammasome formation and NF-κB activation in vivo. Bay11-7082 decreased proteinuria, blood urea nitrogen, resulting in dramatically attenuated renal damage. Bay11-7082-treated mice had decreased serum anti-dsDNA level and less renal immune complex deposition. The IL-1β, TNF-α and chemokine (C-C Motif) ligand 2 (CCL2) levels and infiltration of macrophages as well as the mortality were significantly reduced by Bay11-7082 treatment. This study suggests that dual inhibition of NLRP3 inflammasome and NF-κB activation using Bay11-7082 or its analogues may be a promising therapeutic strategy for preventing the progression of LN.

Topics: Animals; Carrier Proteins; Chemokine CCL2; Female; Gene Expression Regulation; Inflammation; Kidney; Lupus Nephritis; Macrophages; Mice; Mice, Inbred MRL lpr; NF-kappa B; Nitriles; NLR Family, Pyrin Domain-Containing 3 Protein; Random Allocation; Sulfones; Tumor Necrosis Factor-alpha

Age-related macular degeneration (AMD) is the predominant cause of irreversible blindness in the elderly population. Despite intensive basic and clinical research, its pathogenesis remains unclear. However, evidence suggests that immunological and inflammatory factors contribute to the pathogenesis of AMD. A newly identified cytokine, IL-33, appears to be an important pro-inflammatory cytokine promoting tissue inflammation. In this study, IL-33 was increased through amyloid-beta(1-40) (Aβ(1-40)) stimulation and regulated inflammatory cytokines including IL-6, IL-8, IL-1β, and TNF-α secretion using different signaling pathways in retinal pigment epithelium (RPE) cells. Furthermore, ST2L, the important component of the IL-33 receptor, was significantly increased following recombinant human IL-33 stimulation in RPE cells. These findings suggest that IL-33-mediated inflammatory responses in RPE cells are involved in the pathogenesis of AMD. Greater understanding of the inflammatory effect of IL-33 and its role in RPE cells should aid the development of future clinical therapeutics and enable novel pharmacological approaches towards the prevention of AMD.

Topics: Amyloid beta-Peptides; Anthracenes; Butadienes; Cell Line; Humans; Imidazoles; Inflammation; Interleukin-1 Receptor-Like 1 Protein; Interleukin-1beta; Interleukin-33; Interleukin-6; Interleukin-8; Interleukins; JNK Mitogen-Activated Protein Kinases; Macular Degeneration; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; NF-kappa B; Nitriles; Peptide Fragments; Pyridines; Receptors, Cell Surface; Retinal Pigment Epithelium; Sulfones; Tumor Necrosis Factor-alpha

Inflammation is an emerging patho-mechanism of diabetes and its complications. NF-κB pathway is one of the central machinery initiating and propagating inflammatory responses. The present study envisaged the involvement of NF-κB inflammatory cascade in the pathophysiology of diabetic neuropathy using BAY 11-7082, an IκB phosphorylation inhibitor. Streptozotocin was used to induce diabetes in Sprauge Dawley rats. BAY 11-7082 (1 & 3 mg/kg) was administered to diabetic rats for 14 days starting from the end of six weeks post diabetic induction. Diabetic rats developed deficits in nerve functions and altered nociceptive parameters and also showed elevated expression of NF-κB (p65), IκB and p-IκB along with increased levels of IL-6 & TNF-α and inducible enzymes (COX-2 and iNOS). Furthermore, there was an increase in oxidative stress and decrease in Nrf2/HO-1 expression. We observed that BAY 11-7082 alleviated abnormal sensory responses and deficits in nerve functions. BAY 11-7082 also ameliorated the increase in expression of NF-κB, IκB and p-IκB. BAY 11-7082 curbed down the levels of IL-6, TNF-α, COX-2 and iNOS in the sciatic nerve. Lowering of lipid peroxidation and improvement in GSH levels was also seen along with increased expression of Nrf2/HO-1. Thus it can be concluded that NF-κB expression and downstream expression of proinflammatory mediators are prominent features of nerve damage leading to inflammation and oxidative stress and BAY 11-7082 was able to ameliorate experimental diabetic neuropathy by modulating neuroinflammation and improving antioxidant defence.

Topics: Animals; Blotting, Western; Diabetic Neuropathies; Glutathione; Immunohistochemistry; Inflammation; Interleukin-6; Male; Malondialdehyde; NF-kappa B; Nitriles; Oxidative Stress; Rats; Rats, Sprague-Dawley; Sulfones; Thiobarbituric Acid Reactive Substances; Tumor Necrosis Factor-alpha

The dynamics between inflammatory factors, mechanical stress, and healing factors, in an intra-articular joint, are very complex after injury. Injury to intra-articular tissue [anterior cruciate ligament (ACL), synovium] results in hypoxia, accumulation of various pro-inflammatory factors, cytokines, and metalloproteases. Although the presence of increased amounts of matrix-metalloproteinases (MMP) in the joint fluid after knee injury is considered the key factor for ACL poor healing ability; however, the exact role of collective participants of the joint fluid on MMP-2 activity and production has not been fully studied yet. To investigate the combined effects of mechanical injury, inflammation and hypoxia induced factor-1α (HIF-1α) on induction of MMP-2; we mimicked the microenvironment of joint cavity after ACL injury. The results show that TNF-α and IL-1β elevate the activity of MMP-2 in a dose- and time-dependent manner. In addition, mechanical stretch further enhances the MMP-2 protein levels with TNF-α, IL-1β, and their mixture. CoCl(2) -induced HIF-1α (100 and 500 µM) also increases the levels and activity of MMP-2. Mechanical stretch has a strong additional effect on MMP-2 production with HIF-1α. Our results conclude that mechanical injury, HIF-1α and inflammatory factors collectively induce increased MMP-2 production in ACL fibroblasts, which was inhibited by NF-κB pathway inhibitor (Bay-11-7082).

Topics: Adult; Anterior Cruciate Ligament; Cells, Cultured; Cobalt; Drug Synergism; Fibroblasts; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; In Vitro Techniques; Inflammation; Interleukin-1beta; Matrix Metalloproteinase 2; Middle Aged; NF-kappa B; Nitriles; Stress, Mechanical; Sulfones; Tumor Necrosis Factor-alpha; Young Adult

Endothelial progenitor cells (EPCs) are decreased in number and function in type 2 diabetes. Mechanisms by which this dysfunction occurs are largely unknown. We tested the hypothesis that a chronic inflammatory environment leads to insulin signaling defects in EPCs and thereby reduces their survival. Modifying EPCs by a knockdown of nuclear factor-κB (NF-κB) can reverse the insulin signaling defects, improve EPC survival, and decrease neointimal hyperplasia in Zucker fatty rats postangioplasty.. EPCs from Zucker fatty insulin-resistant rats were cultured and exposed to tumor necrosis factor-α (TNF-α). Insulin signaling defects and apoptosis were measured in the presence and absence of an NF-κB inhibitor, BAY11. Then, EPCs were modified by a knockdown of NF-κB (RelA) and exposed to TNF-α. For in vivo experiments, Zucker fatty rats were given modified EPCs post-carotid angioplasty. Tracking of EPCs was done at various time points, and neointimal hyperplasia was measured 3 weeks later.. Insulin signaling as measured by the phosphorylated-to-total AKT ratio was reduced by 56% in EPCs exposed to TNF-α. Apoptosis was increased by 71%. These defects were reversed by pretreatment with an NF-κB inhibitor, BAY11. Modified EPCs exposed to TNF-α showed a lesser reduction (RelA 20%) in insulin-stimulated AKT phosphorylation versus a 55% reduction in unmodified EPCs. Apoptosis was 41% decreased for RelA knockdown EPCs. Noeintimal hyperplasia postangioplasty was significantly less in rats receiving modified EPCs than in controls (intima-to-media ratio 0.58 vs. 1.62).. In conclusion, we have shown that insulin signaling and EPC survival is impaired in Zucker fatty insulin resistant rats. For the first time, we have shown that this defect can be significantly ameliorated by a knockdown of NF-κB and that these EPCs given to Zucker fatty rats decrease neointimal hyperplasia post-carotid angioplasty.

Topics: Animals; Apoptosis; Cells, Cultured; Diabetes Mellitus, Type 2; Endothelial Cells; Enzyme-Linked Immunosorbent Assay; Inflammation; Insulin Resistance; Interleukin-8; NF-kappa B; Nitriles; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Rats, Zucker; Reverse Transcriptase Polymerase Chain Reaction; Stem Cells; Sulfones; Tumor Necrosis Factor-alpha

Quercetin is anti-inflammatory in macrophages by inhibiting lipopolysaccharide (LPS)-mediated increases in cytokine and nitric oxide production but there is little information regarding the corresponding effect on the vasculature. We have examined the effect of quercetin, and its principal human metabolites, on inflammatory changes in the porcine isolated coronary artery.. Porcine coronary artery segments were incubated overnight at 37°C in modified Krebs-Henseleit solution with or without 1µg·mL(-1) LPS. Some segments were also co-incubated with quercetin-related flavonoids or Bay 11-7082, an inhibitor of NFκB. Changes in isometric tension of segments to vasoconstrictor and vasodilator agents were recorded. Nitrite content of the incubation solution was estimated using the Griess reaction, while inducible nitric oxide synthase was identified immunohistochemically.. Lipopolysaccharide reduced, by 35-50%, maximal contractions to KCl and U46619, thromboxane A(2) receptor agonist, and impaired endothelium-dependent relaxations to substance P. Nitrite content of the incubation medium increased 3- to 10-fold following exposure to LPS and inducible nitric oxide synthase was detected in the adventitia. Quercetin (0.1-10µM) opposed LPS-induced changes in vascular responses, nitrite production and expression of inducible nitric oxide synthase. Similarly, 10µM Bay 11-7082, 10µM quercetin 3'-sulphate and 10µM quercetin 3-glucuronide prevented LPS-induced changes, while myricetin (10µM) was inactive. Myricetin (10µM) prevented quercetin-induced modulation of LPS-mediated nitrite production.. Quercetin, quercetin 3'-suphate and quercetin 3-glucuronide, exerted anti-inflammatory effects on the vasculature, possibly through a mechanism involving inhibition of NFκB. Myricetin-induced antagonism of the effect of anti-inflammatory action of quercetin merits further investigation.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Coronary Vessels; Cytokines; Flavonoids; In Vitro Techniques; Inflammation; Isometric Contraction; Lipopolysaccharides; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Nitriles; Nitrites; Potassium Chloride; Quercetin; Sulfones; Swine

The mouse cholesterol sulfotransferase St2b2 contributes to epidermal differentiation by biosynthesizing cholesterol sulfate (CS) from cholesterol in the epidermis. 12-O-Tetradecanoylphorbol-13-acetate (TPA) causes epidermal hyperplasia, an abnormal increase in epidermal cell numbers resulting from aberrant cell differentiation and an increase in St2b2 protein levels. The mechanisms underlying enhanced St2b2 expression and the pathophysiologic significance of the increased expression are unclear, however. To verify whether increased St2b2 levels are necessary for TPA-induced epidermal hyperplasia, the effects of St2b2-specific small hairpin RNA (St2b2-shRNA) on hyperplasia were examined in mice. St2b2-shRNA clearly suppressed TPA-induced epidermal hyperplasia and the expression of a marker of epidermal differentiation, involucrin (INV). Interestingly, treating mouse epidermal cells with tumor necrosis factor-alpha (TNFα) increased St2b2 expression. Furthermore, treatment with TNFα-siRNA or anti-TNF receptor antibodies reduced the TPA-induced enhancement of St2b2 expression. Treatment with BAY 11-7082, a specific inhibitor of nuclear factor-kappa B (NF-κB), diminished TPA-induced St2b2 expression. These results suggested that enhancement of St2b2 expression by TPA treatment occurs mainly through the TNFα-NF-κB inflammatory signaling pathway, which in turn leads to increased CS concentrations in epidermal cells and hyperplasia.

Topics: Animals; Antibodies; Cholesterol Esters; Epidermis; Female; Hyperplasia; Inflammation; Mice; Mice, Inbred Strains; NF-kappa B; Nitriles; Protein Precursors; Receptors, Tumor Necrosis Factor; RNA, Small Interfering; Signal Transduction; Skin Neoplasms; Sulfones; Sulfotransferases; Tetradecanoylphorbol Acetate; Tumor Necrosis Factor-alpha

Activation of the inflammasome generates the pro-inflammatory cytokines interleukin-1 beta and -18, which are important mediators of inflammation. Abnormal activation of the inflammasome leads to many inflammatory diseases, including gout, silicosis, neurodegeneration, and genetically inherited periodic fever syndromes. Therefore, identification of small molecule inhibitors that target the inflammasome is an important step toward developing effective therapeutics for the treatment of inflammation. Here, we show that the herbal NF-kappaB inhibitory compound parthenolide inhibits the activity of multiple inflammasomes in macrophages by directly inhibiting the protease activity of caspase-1. Additional investigations of other NF-kappaB inhibitors revealed that the synthetic I kappaB kinase-beta inhibitor Bay 11-7082 and structurally related vinyl sulfone compounds selectively inhibit NLRP3 inflammasome activity in macrophages independent of their inhibitory effect on NF-kappaB activity. In vitro assays of the effect of parthenolide and Bay 11-7082 on the ATPase activity of NLRP3 demonstrated that both compounds inhibit the ATPase activity of NLRP3, suggesting that the inhibitory effect of these compounds on inflammasome activity could be mediated in part through their effect on the ATPase activity of NLRP3. Our results thus elucidate the molecular mechanism for the therapeutic anti-inflammatory activity of parthenolide and identify vinyl sulfones as a new class of potential therapeutics that target the NLRP3 inflammasome.

Topics: Animals; Anti-Inflammatory Agents; Bone Marrow Cells; Caspase 1; Cell Death; Humans; Immunoblotting; Inflammation; L-Lactate Dehydrogenase; Macrophages; Mice; NF-kappa B; Nitriles; Sesquiterpenes; Sulfones

The nuclear respiratory factor-1 (NRF1) gene is activated by lipopolysaccharide (LPS), which might reflect TLR4-mediated mitigation of cellular inflammatory damage via initiation of mitochondrial biogenesis. To test this hypothesis, we examined NRF1 promoter regulation by NFκB, and identified interspecies-conserved κB-responsive promoter and intronic elements in the NRF1 locus. In mice, activation of Nrf1 and its downstream target, Tfam, by Escherichia coli was contingent on NFκB, and in LPS-treated hepatocytes, NFκB served as an NRF1 enhancer element in conjunction with NFκB promoter binding. Unexpectedly, optimal NRF1 promoter activity after LPS also required binding by the energy-state-dependent transcription factor CREB. EMSA and ChIP assays confirmed p65 and CREB binding to the NRF1 promoter and p65 binding to intron 1. Functionality for both transcription factors was validated by gene-knockdown studies. LPS regulation of NRF1 led to mtDNA-encoded gene expression and expansion of mtDNA copy number. In cells expressing plasmid constructs containing the NRF-1 promoter and GFP, LPS-dependent reporter activity was abolished by cis-acting κB-element mutations, and nuclear accumulation of NFκB and CREB demonstrated dependence on mitochondrial H(2)O(2). These findings indicate that TLR4-dependent NFκB and CREB activation co-regulate the NRF1 promoter with NFκB intronic enhancement and redox-regulated nuclear translocation, leading to downstream target-gene expression, and identify NRF-1 as an early-phase component of the host antibacterial defenses.

Topics: Animals; Chromatin Immunoprecipitation; Computational Biology; Cyclic AMP Response Element-Binding Protein; DNA, Mitochondrial; Electrophoretic Mobility Shift Assay; Hep G2 Cells; Humans; Immunoblotting; Inflammation; Introns; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mitochondria; NF-kappa B; Nitriles; Nuclear Respiratory Factor 1; Promoter Regions, Genetic; Protein Binding; Sulfones

Despite development of therapeutic modalities, myocardial ischemia-reperfusion (I/R) injury remains an important cause of cardiac dysfunction. Multiple strategies exist experimentally, but few are clinically available. Nuclear factor kappa-B (NF-κB) is a key transcription factor in the inflammatory response and is implicated in I/R injury. We hypothesized that the NFκB inhibitor BAY 11-7082 (BAY) would decrease the extent of injury after myocardial I/R. Hypoxia-reoxygenation (H/R) was induced in rat neonatal cardiomyocytes with or without BAY pretreatment. NF-κB activation, vascular cell adhesion molecule (VCAM)-1, and monocyte chemoattractant protein (MCP)-1 were assayed by immunocytochemistry, Western blot or reverse transcriptase-polymerase chain reaction (RT-PCR). Sprague-Dawley rats (n = 7) were administered BAY (130 µg/kg) and I/R was induced by ligation of the left anterior descending artery (LAD) for 30 minutes followed by reperfusion. Infarct size was analyzed after 24 hours. At 2 weeks, echocardiography was performed to evaluate ventricular function and hearts were analyzed for fibrosis and apoptosis. BAY treatment inhibited NF-κB p65 activation, as well as VCAM-1 and MCP-1 expression induced by H/R in cardiomyocytes. Compared with control rats, BAY pretreated rats showed reduced infarct size. Echocardiograms demonstrated preserved systolic function as a fractional shortening in the BAY+I/R group (P < 0.05). Fibrosis was reduced in the BAY+I/R group (P < 0.05) and apoptosis was also reduced in the BAY+I/R group (P < 0.05).In the rat myocardial I/R injury model, BAY significantly reduced the infarct size, and preserved myocardial function. These data demonstrate that a currently available and well-tolerated inhibitor of NF-κB can decrease the risk of myocardial injury associated with I/R.

Topics: Animals; Apoptosis; Blotting, Western; Cells, Cultured; Chemokine CCL2; Disease Models, Animal; Immunohistochemistry; Inflammation; Myocytes, Cardiac; NF-kappa B; Nitriles; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sulfones

Barrett's esophagus, a columnar metaplasia of the lower esophagus epithelium related to gastroesophageal reflux disease, is the strongest known risk factor for the development of esophageal adenocarcinoma (EAC). Understanding the signal transduction events involved in esophageal epithelium carcinogenesis may provide insights into the origins of EAC and may suggest new therapies. To elucidate the molecular pathways of bile acid-induced tumorigenesis, the newly identified inflammation-associated signaling pathway involving I kappaB kinases beta (IKK beta), tuberous sclerosis complex 1 (TSC1), and mammalian target of rapamycin (mTOR) downstream effector S6 kinase (S6K1) was confirmed to be activated in immortalized Barrett's CPC-A and CPC-C cells and esophageal cancer SEG-1 and BE3 cells. Phosphorylation of TSC1 and S6K1 was induced in response to bile acid stimulation. Treatment of these cells with the mTOR inhibitor rapamycin or the IKK beta inhibitor Bay 11-7082 suppressed bile acid-induced cell proliferation and anchorage-independent growth. We next used an orthotopic rat model to evaluate the role of bile acid in the progression of Barrett's esophagus to EAC. Of interest, we found high expression of phosphorylated IKK beta (pIKK beta) and phosphorylated S6K1 (pS6K1) in tumor tissues and the Barrett's epithelium compared with normal epithelium. Furthermore, immunostaining of clinical EAC tissue specimens revealed that pIKK beta expression was strongly correlated with pS6K1 level. Together, these results show that bile acid can deregulate TSC1/mTOR through IKK beta signaling, which may play a critical role in EAC progression. In addition, Bay 11-7082 and rapamycin may potentially be chemopreventive drugs against Barrett's esophagus-associated EAC.

Topics: Adenocarcinoma; Barrett Esophagus; Bile Acids and Salts; Cell Division; Chenodeoxycholic Acid; Esophageal Neoplasms; Gastroesophageal Reflux; Gene Expression Regulation, Neoplastic; Humans; Inflammation; NF-kappa B; Nitriles; Protein Kinases; RNA, Small Interfering; Sirolimus; Sulfones; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein; Tumor Suppressor Proteins; Ursodeoxycholic Acid

The ability of human neutrophils to express a variety of genes encoding inflammatory mediators is well documented, and mounting evidence suggests that neutrophil-derived cytokines and chemokines contribute to the recruitment of discrete leukocyte populations at inflammatory sites. Despite this, our understanding of the signaling intermediates governing the generation of inflammatory cytokines by neutrophils remains fragmentary. Here, we report that inhibitors of the p38 MAPK and MEK pathways substantially diminish the release of (and in the case of p38 inhibitors, the gene expression of) several inflammatory cytokines in neutrophils stimulated with LPS or TNF. In addition, various NF-kappaB inhibitors were found to profoundly impede the inducible gene expression and release of inflammatory cytokines in these cells. The MAPK inhibitors did not affect NF-kappaB activation; instead, the transcriptional effects of the p38 MAPK inhibitor appear to involve transcriptional factor IID. Conversely, the NF-kappaB inhibitors failed to affect the activation of MAPKs. Finally, the MAPK inhibitors were found to prevent the activation a key component of the translational machinery, S6 ribosomal protein, in keeping with their post-transcriptional impact on cytokine generation. To our knowledge, this constitutes the first demonstration that in neutrophils, the inducible expression of proinflammatory cytokines by physiological stimuli largely reflects the ability of the latter to activate NF-kappaB and selected MAPK pathways. Our data also raise the possibility that NF-kappaB or MAPK inhibitors could be useful in the treatment of inflammatory disorders in which neutrophils predominate.

Topics: Boronic Acids; Cell Differentiation; Cytokines; Humans; Inflammation; Leupeptins; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Neutrophils; NF-kappa B; Nitriles; Proline; Protein Kinase Inhibitors; Structure-Activity Relationship; Sulfones; Thiocarbamates

Hydrogen sulfide (H2S) is now considered an endogenous, gaseous mediator, which has been demonstrated to be involved in many inflammatory states. However, the mechanism of its proinflammatory function remains unknown. In the present study, we used IFN-gamma-primed human monocytic cell line U937 to investigate the effects of H2S in vitro on monocytes. We found that treatment with the H2S donor, sodium hydrosulfide, led to significant increases in the mRNA expression and protein production of TNF-alpha, IL-1beta, and IL-6 in U937 cells. H2S-triggered monocyte activation was confirmed further by the up-regulation of CD11b expression on the cell surface. We also observed that H2S could induce a rapid degradation of IkappaBalpha and subsequent activation of NF-kappaB p65, and this effect was attenuated by Bay 11-7082, a specific inhibitor of NF-kappaB. Furthermore, pretreatment of cells with Bay 11-7082 substantially inhibited the secretion of TNF-alpha, IL-1beta, and IL-6 induced by H2S. We also found that H2S stimulated the phosphorylation and activation of ERK1/2, but not of p38 MAPK and JNK, and pretreatment with PD98059, a selective MEK1 antagonist, could inhibit H2S-induced NF-kappaB activation markedly. Together, our findings suggest for the first time that H2S stimulates the activation of human monocytes with the generation of proinflammatory cytokines, and this response is, at least partially, through the ERK-NF-kappaB signaling pathway.

Topics: CD11b Antigen; Cell Line; Cytokines; Dose-Response Relationship, Drug; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Gene Expression Profiling; Humans; I-kappa B Proteins; Inflammation; Monocytes; NF-kappa B; NF-KappaB Inhibitor alpha; Nitriles; Phosphorylation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Structure-Activity Relationship; Sulfides; Sulfones; Time Factors; Up-Regulation

The fungal secondary metabolite panepoxydone has been recently described as an inhibitor of NF-kappaB activation which is a pivotal regulator of the inflammatory and immune response. These findings have led to propose that panepoxydone may be useful as anti-inflammatory agent. In this study we investigated for the first time the effects of panepoxydone on inflammatory gene expression in the monocytic cell line MonoMac6, stimulated with lipopolysaccharide (LPS) and the phorbolester 12-O-tetradecanoylphorbol-13-acetate (TPA). DNA microarray analysis of 110 human genes known to be strongly regulated during inflammation, combined with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) revealed that low micromolar concentrations (12-24 microM) of panepoxydone strongly inhibited the expression of thirty-three NF-kappaB dependent pro-inflammatory genes such as the chemokines CCL3, CCL4, CCL8; CXCL8, CXCL10, CXCL20, the cytokines IL-1, IL-6, TNF-alpha, pro-inflammatory enzymes like COX-2, and components of the REL/NF-kappaB/IkappaB family without significant effects on the expression of house-keeping genes. Panepoxydone strongly inhibited hTNF-alpha, IL-8 and NF-kappaB promoter activity in LPS/TPA stimulated MonoMac6 cells with IC(50) values of 0.5-1 microg/ml by blocking the phosphorylation of IkappaB and subsequent binding of the activated NF-kappaB transcription factor to the DNA. From our data, panepoxydone may serve as lead structure for the development of transcription-based inhibitors of pro-inflammatory gene expression.

Topics: Apoptosis; Autoimmune Diseases; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Survival; Electrophoretic Mobility Shift Assay; Fluorescein-5-isothiocyanate; Gene Expression; Genes, Reporter; Humans; Inflammation; Lipopolysaccharides; NF-kappa B; Nitriles; Oligonucleotide Array Sequence Analysis; Propidium; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sulfones; Tetradecanoylphorbol Acetate

Lipopolysaccharide (LPS), a major component of the outer membrane of Gram-negative bacteria, activates a broad spectrum of signaling pathways in immune cells. In this article, RAW264.7 cells have been stimulated for 4 h with 1 microg/mL of LPS in the presence or not of specific inhibitors of the NF-kappaB pathway (BAY 11-7082) and the PI3K pathway (LY294002). Gene expression profiles were characterized using the DNA microarray "Dual Chip Mouse Inflammation." This array monitors the expression of 233 genes encoding proteins playing a role in inflammation. Both signaling pathways exert an important role in the response to LPS, but they are not completely overlapping. For example, genes encoding the PAF receptor, PAI-1, PlA2 (group V), IL-13 receptor (alpha2), and GTP cyclohydrolase 1, were upregulated after LPS treatment, but this upregulation was counteracted by LY294002. The same was observed for BAY 11-7082: genes encoding the kit ligand, TLR2, or TNFRSF5 were mainly under the control of NF-kappaB. NF-kappaB plays an important role in the macrophage response to LPS, but we have also shown that the PI3K pathway partially contributes to it. Further experiments with the specific inhibitor of mTOR (rapamycin) will provide more information on the specific contribution of the PI3K/mTOR pathway in the inflammatory response in LPS-stimulated macrophages.

Topics: Animals; Chromones; Gene Expression Profiling; Gene Expression Regulation; Inflammation; Lipopolysaccharides; Macrophages; Mice; Morpholines; NF-kappa B; Nitriles; Oligonucleotide Array Sequence Analysis; Phosphatidylinositol 3-Kinases; Protein Kinases; Signal Transduction; Sulfones; TOR Serine-Threonine Kinases; Up-Regulation

Neuropeptides play an important role in the active communication between the nervous and immune systems. Substance P (SP) is a prominent neuropeptide involved in neurogenic inflammation and has been reported to exert various proinflammatory actions on inflammatory leukocytes including neutrophils. The present study further investigated the modulatory effect of SP (1 muM) on chemokine production and chemokine receptor expression in primary mouse neutrophils. Our results showed that SP primed neutrophils for chemotactic responses not only to the CXC chemokine macrophage inflammatory protein (MIP)-2/CXCL2 but also to the CC chemokine MIP-1alpha/CCL3. The activating effect of SP on neutrophils was further evidenced by upregulation of the CD11b integrin, the activation marker of neutrophils. SP induced both the mRNA and protein expression of the chemokines MIP-1alpha/CCL3 and MIP-2/CXCL2 in neutrophils and upregulated the chemokine receptors CC chemokine receptor (CCR)-1 and CXC chemokine receptor (CXCR)-2. This stimulatory effect on chemokine and chemokine receptor expression in neutrophils was further found to be neurokinin-1 receptor (NK-1R) specific. Pretreatment with selective NK-1R antagonists inhibited SP-triggered activation of neutrophils and chemokine and chemokine receptor upregulation. Moreover, SP-induced chemokine upregulation was NF-kappaB dependent. SP time dependently induced NF-kappaB p65 binding activity, IkappaBalpha degradation, and NF-kappaB p65 nuclear translocation in neutrophils. Inhibition of NF-kappaB activation with its inhibitor Bay11-7082 (10 muM) abolished SP-induced NF-kappaB binding activity and upregulation of MIP-1alpha/CCL3 and MIP-2/CXCL2 in neutrophils. Together, these results suggest that SP exerts a direct stimulatory effect on the expression of chemokines and chemokine receptors in mouse neutrophils. The effect is NK-1R mediated, involving NF-kappaB activation.

Topics: Active Transport, Cell Nucleus; Animals; Biphenyl Compounds; CD11b Antigen; Cells, Cultured; Chemokine CCL3; Chemokine CCL4; Chemokine CXCL2; Chemokines; Chemokines, CC; Chemotaxis, Leukocyte; Dose-Response Relationship, Drug; I-kappa B Proteins; Inflammation; Macrophage Inflammatory Proteins; Male; Mice; Neuroimmunomodulation; Neutrophils; Nitriles; Receptors, CCR1; Receptors, Chemokine; Receptors, Interleukin-8B; Receptors, Neurokinin-1; Recombinant Proteins; RNA, Messenger; Signal Transduction; Substance P; Sulfones; Transcription Factor RelA; Up-Regulation

Ionizing radiation (IR) is associated with thrombotic vascular occlusion predicting a poor clinical outcome. Our study examined whether IR induced tissue factor (TF) expression and procoagulability. We further investigated coordinated gene alterations associated with TF upregulation in the myelomonocytic leukemia THP-1 cells.. TF expression was determined by quantitative Reverse Transcriptase (TaqMan) PCR, TF ELISA and TF activity by a two stage chromogenic assay in the time course of days 1, 3, 7, 10, and 17 post IR. To detect IR-induced alterations in gene expression, Affymetrix HG U133 Plus 2.0 microarrays were used. RESULTS IR induced a significant increase in TF/GAPDH mRNA ratios and cellular TF protein on days 3 and 7 post IR (20 Gy [p>or=0.01] and 40 Gy [p or=0.001] vs. control respectively), suggesting IR immediately alters the cellular thrombogenicity. TF upregulation post IR was confirmed in PBMNCs. Gene expression profiling showed IR increased the expression of inflammatory and apoptosis-related pathways known to be involved in the regulation of TF expression.. TF upregulation together with inflammation and apoptosis may increase the thrombogenicity of tissues. The demonstrated upregulation of TF might play a pivotal role in radiation associated thrombosis.

Topics: Apoptosis; Blood Coagulation Factors; Cell Line, Tumor; Enzyme-Linked Immunosorbent Assay; Factor Xa; Gene Expression Profiling; Gene Expression Regulation, Leukemic; Humans; Inflammation; Leukemia, Myelomonocytic, Acute; Neoplasm Proteins; NF-kappa B; Nitriles; Oligonucleotide Array Sequence Analysis; Particle Accelerators; Radiation, Ionizing; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Sulfones; Thrombophilia; Thromboplastin

There is much evidence to indicate a role for adipocytokines in insulin resistance and/or type 2 diabetes mellitus. In experimental models, oral salicylates, through their ability to interfere with the nuclear factor-kappa B (NF-kappa B) transcription pathway, have been demonstrated to reverse insulin resistance. The aim of this study was to investigate whether NF-kappa B regulates the release of adipocytokines in human adipose tissue and skeletal muscle. Human sc adipose tissue and skeletal muscle (obtained from normal pregnant women) were incubated in the absence (control) or presence of two NF-kappa B inhibitors sulfasalazine (1.25, 2.5, and 5 mm) and BAY 11-7082 (25, 50, and 100 microm). After an 18-h incubation, the tissues were collected, and NF-kappa B p65 DNA-binding activity and I kappa B kinase (IKK-beta) and insulin receptor-beta protein expression were assessed by ELISA and Western blotting, respectively. The incubation medium was collected, and the release of TNF-alpha, IL-6, IL-8, resistin, adiponectin, and leptin was quantified by ELISA. Treatment of adipose tissue and skeletal muscle with sulfasalazine and BAY 11-7082 significantly inhibited the release of IL-6, IL-8, and TNF-alpha; NF-kappa B p65 DNA-binding activity; and IKK-beta protein expression (P < 0.05, by Newman-Keuls test). There was no effect of sulfasalazine and BAY 11-7082 on resistin, adiponectin, or leptin release. Both sulfasalazine and BAY 11-7082 increased the adipose tissue and skeletal muscle expression of insulin receptor-beta. The data presented in this study demonstrate that the IKK-beta/NF-kappa B transcription pathway is a key regulator of IL-6, IL-8, and TNF-alpha release from adipose tissue and skeletal muscle. Control of the IKK-beta/NF-kappa B pathway may therefore provide an alternative therapeutic strategy for regulating aberrant cytokine release and thereby alleviating insulin resistance in type 2 diabetes mellitus.

Topics: Adiponectin; Adipose Tissue; Adult; Anti-Inflammatory Agents, Non-Steroidal; Blotting, Western; Cell Survival; Cytokines; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Female; Gene Expression Regulation; Hormones, Ectopic; Humans; I-kappa B Kinase; Inflammation; Intercellular Signaling Peptides and Proteins; Interleukin-6; Interleukin-8; Leptin; Muscle, Skeletal; NF-kappa B; Nitriles; Pregnancy; Protein Binding; Protein Serine-Threonine Kinases; Receptor, Insulin; Resistin; Sulfasalazine; Sulfones; Time Factors; Tissue Distribution; Transcription, Genetic; Tumor Necrosis Factor-alpha

Several proinflammatory cytokines including IL-6 and IL-8 are produced by human adipocytes, but it is still unclear how this process is regulated. Angiotensin (Ang) II, which is also produced by adipocytes, might play a role as a regulator. In the present study, we investigated the effect of Ang II on the production of IL-6 and IL-8 in in vitro differentiated human adipocytes.. Isolation of preadipocytes and differentiation of these cells into adipocytes, Real-time quantitative reverse-transcriptase polymerase chain reaction, Western-blot, enzyme-linked immunosorbent assay, and electromobility shift assay. Ang II-stimulated IL-6 and IL-8 mRNA expression and protein release in a time- and concentration-dependent way. This action of Ang II was completely blocked by the NF-kappaB-blocker Bay 117082 and the AT1 blocker candesartan, but only partially by the AT2-blocker PD 123 319. Incubation of adipocytes with Ang II resulted in an increased phosphorylation of the p65 subunit of NF-kappaB and an increased translocation of NF-kappaB to the nucleus.. Ang II stimulates IL-6 and IL-8 production and release from human adipocytes by a NF-kappaB-dependent pathway. This proinflammatory action of Ang II seems to be mediated by the AT1 and less by the AT2 receptor subtype.

Topics: Adipocytes; Adult; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin II Type 2 Receptor Blockers; Benzimidazoles; Biphenyl Compounds; Cells, Cultured; Electrophoretic Mobility Shift Assay; Female; Humans; Imidazoles; Inflammation; Interleukin-6; Interleukin-8; NF-kappa B; Nitriles; Phosphorylation; Protein Processing, Post-Translational; Protein Transport; Pyridines; Receptor, Angiotensin, Type 1; RNA, Messenger; Sulfones; Tetrazoles; Transcription Factor RelA; Transcriptional Activation

The objective of this study was to test the hypothesis that an oxidative stress can serve as a signal to regulate the expression of CCR5. When human monocytes were exposed to graded concentration of hydrogen peroxide (H(2)O(2)), CCR5 mRNA levels increased maximally at 4 h of exposure to 200 microM of H(2)O(2) and decreased by 24 h of treatment. Pretreatment of monocytes with the NF-kappaB inhibitor BAY 11-8072 blocked the H(2)O(2)-induced augmentation of CCR5 mRNA expression, suggesting a role for this transcription factor in the regulation of CCR5 expression. CCR5 protein expression on the plasma membrane was also increased by treatment with H(2)O(2,) as assessed by flow cytometry. This was accompanied by enhanced responsiveness of H(2)O(2)-pretreated monocytes to the CCR5 ligand MIP-1beta in terms of chemotaxis and c-fos gene activation. Our results suggest that oxidative stress may indeed modulate the expression of chemokine receptors and thus contribute to regulation of the inflammatory process.

Topics: Catalase; Cell Membrane; Cells, Cultured; Chemokine CCL4; Gene Expression Regulation; Genes, fos; Humans; Hydrogen Peroxide; Inflammation; Macrophage Inflammatory Proteins; Monocytes; NF-kappa B; Nitriles; Organic Chemicals; Oxidative Stress; Reactive Oxygen Species; Receptors, CCR5; RNA, Messenger; Sulfones; Time Factors; Transcriptional Activation; Up-Regulation