NF-kappaB Gene Expression Research Articles

Increased cortical neuronal survival during liver injury: effect of gamma aminobutyric acid and 5-HT chitosan nanoparticles.

Use of nanoparticulate drug delivery system for an effective therapeutic outcome against diseases gains immense hope in the study of drug delivery to partially hepatectomised rats. In the present study, partially hepatectomised rats treated with Gamma aminobutyric acid (GABA) and serotonin (5-HT) chitosan nanoparticles, individually and in combination, were evaluated to analyse their role in GABAB, and 5-HT2A receptors functional regulation, interrelated neuronal survival mechanisms by nuclear factor kappa B (NF-kappaB), tumour necrosis factor-a (TNF-alpha), Akt-1 and the antioxidant enzyme superoxide dismutase (SOD) in the cerebral cortex. A significant decrease in GABA, and 5-HT2A receptor numbers and gene expressions denoted a homeostatic adjustment by the cerebral cortex to trigger the sympathetic innervations during elevated DNA synthesis in the liver. GABAB, and 5-HT2A signalling directly influenced the cyclic AMP response element binding protein (CREB) expression, neuronal survival and ROS mediated cell damage which was confirmed from the gene expression of NF-kappaB, TNF-alpha, Akt-1 and SOD. In addition to enhanced hepatocyte proliferation, GABA and 5-HT chitosan nanoparticle treatment protected the neurons from ROS mediated cell damage and promoted their survival in the cerebral cortex. This has application in liver based diseases and treatments with nanosized active compounds.

The Role of NF-κB and H3K27me3 Demethylase, Jmjd3, on the Anthrax Lethal Toxin Tolerance of RAW 264.7 Cells

BackgroundIn Bacillus anthracis, lethal toxin (LeTx) is a critical virulence factor that causes immune suppression and toxic shock in the infected host. NF-κB is a key mediator of the inflammatory response and is crucial for the plasticity of first level immune cells such as macrophages, monocytes and neutrophils. In macrophages, this inflammatory response, mediated by NF-κB, can regulate host defense against invading pathogens. A Jumonji C family histone 3 lysine-27 (H3K27) demethylase, Jmjd3, plays a crucial role in macrophage plasticity and inflammation. Here we report that NF-κB and Jmjd3 can modulate the LeTx intoxication resistance of RAW 264.7 cells.Principal FindingsThis study showed that a 2 h exposure of macrophages to LeTx caused substantial cell death with a survival rate of around 40%. The expression of the Jmjd3 gene was induced 8-fold in intoxication-resistant cells generated by treatment with lipopolysaccharides of RAW 264.7 cells. These intoxication-resistant cell lines (PLx intox and PLxL intox) were maintained for 8 passages and had a survival rate of around 100% on secondary exposure to LeTx and lipopolysaccharides. Analysis of NF-κB gene expression showed that the expression of p100, p50 and p65 was induced around 20, 7 and 4 fold, respectively, in both of the intoxication-resistant cell lines following a 2 h treatment with PLxL (0.1+0.1+1 µg/ml). In contrast, these NF-κB genes were not induced following treatment with PLx treatment at the same concentrations.ConclusionsAlthough LeTx influences macrophage physiology and causes defects of some key signaling pathways such as GSK3β which contributes to cytotoxicity, these results indicate that modulation of NF-κB by p50, p100 and Jmjd3 could be vital for the recovery of murine macrophages from exposure to the anthrax lethal toxin.

Nuclear factor‐kappa B as a promising target for selenium chemoprevention in rat hepatocarcinogenesis

Selenium's molecular mechanism for cancer chemoprevention remains unknown. We aimed to study the gene expression of nuclear factor-kappaB (NF-kappaB), tumor growth factor-alpha (TGF-alpha) and cyclin D1 and the effects of sodium selenite using preventive and therapeutic approaches in chemically-induced hepatocarcinogenesis in rats. Rats were divided randomly into six groups: negative control, positive control (diethyl nitrosamine [DEN] + 2-acetylaminofluorene [2-AAF]), preventive group, preventive control (respective control for preventive group), therapeutic group and therapeutic control (respective control for therapeutic group). The relative gene expression of NF-kappaB, TGF-alpha and cyclin D1 in liver tissues were measured using real-time polymerase chain reaction. The findings showed that the gene expression of NF-kappaB in the preventive group and its respective control was significantly lower (P < 0.05) when compared with both the negative and positive controls. However, the expression of NF-kappaB in the positive controls and therapeutic group was significantly higher (P < 0.05) when compared with the negative controls. The expression of TGF-alpha and cyclin D1 was insignificant in all groups. The inhibition of the NF-kappaB pathway in the initiation phase of hepatocarcinogenesis could be a promising target for selenium chemoprevention. However, further studies are required.

RIP2 Is Required for NOD Signaling But Not for Th1 Cell Differentiation and Cellular Allograft Rejection

Two previous reports that receptor-interacting protein (RIP)-2 knockout (RIP2-/-) mice had defective nuclear factor-kappa B (NF-kappaB) signaling and T helper (Th)1 immune responses had led us to believe that this putative serine-threonine kinase might be a possible target for transplant immunosuppression. Thus, we tested whether RIP2-/- mice were able to reject vascularized allografts. Surprisingly, we found that T cells from RIP2-/- mice proliferated and produced interferon (IFN)-gamma after allostimulation in vitro. Moreover, naïve RIP2-/- CD4+ T cells differentiated normally into Th1 or Th2 cells under appropriate cytokine microenvironments. Consistent with these findings, no difference in allograft survival was observed between wild-type and RIP2-/- recipient mice, and rejection had similar pathology and cytokine profiles in both types of recipients. RIP2 deficiency was associated with defective NOD signaling, but this did not affect T-cell receptor (TCR)-dependent activation of the canonical NF-kappaB signaling or expression of NF-kappaB genes in rejecting allografts. Our data demonstrate that RIP2-deficient mice have intact canonical NF-kappaB signaling and can mount Th1-mediated alloresponses and reject vascularized allografts as efficiently as wild-type mice, thus arguing against RIP2 as a primary target for immunosuppression.

5-Androstenediol Promotes Survival of γ-Irradiated Human Hematopoietic Progenitors through Induction of Nuclear Factor-κB Activation and Granulocyte Colony-Stimulating Factor Expression

5-Androstenediol (5-AED) stimulates hematopoiesis and enhances survival in animals exposed to ionizing radiation (IR), suggesting that this steroid may act on hematopoietic progenitor cells. We used gamma-irradiated primary human CD34(+) hematopoietic progenitor cells to show that 5-AED protects hematopoietic cells from IR damage, as shown by enhanced cell survival, clonogenicity, proliferation, and differentiation. Unlike in tumor cells, IR did not induce nuclear factor-kappaB (NFkappaB) activation in primary progenitors. However, IR stimulated IkappaB(beta) release from NFkappaB/IkappaB complexes and caused NFkappaB1 (p50) degradation. 5-AED stabilized NFkappaB1 in irradiated cells and induced NFkappaB gene expression and NFkappaB activation (DNA binding). 5-AED stimulated interleukin-6 and granulocyte colony-stimulating factor (G-CSF) secretion. The survival-enhancing effects of 5-AED on clonogenic cells were abrogated by small interfering RNA inhibition of NFkappaB gene expression and by neutralization of G-CSF with antibody. The effects of 5-AED on survival and G-CSF secretion were blocked by the NFkappaB inhibitor N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal (MG132). 5-AED had no effect on accumulation of the proapoptotic factor p53 after IR, as determined by Western blot. The results indicate that NFkappaB1 degradation after IR may be responsible for the radiation sensitivity of CD34+ cells compared with tumor cells. 5-AED exerts survival-enhancing effects on irradiated human hematopoietic progenitor cells via induction, stabilization, and activation of NFkappaB, which results in increased secretion of hematopoietic growth factor G-CSF.

RelA is required for IL-1β stimulation of Matrix Metalloproteinase-1 expression in chondrocytes

Interleukin-1beta (IL-1beta) stimulates collagenase-1 (Matrix Metalloproteinase-1 (MMP-1)) expression in articular chondrocytes, leading to cleavage of type II collagen and irreversible cartilage degradation. The nuclear factor-kappa B (NF-kappaB) pathway is potently activated in IL-1beta-stimulated cells and has been implicated as an intermediate in MMP-1 gene expression. However, the roles of individual NF-kappaB family members during IL-1beta-induced MMP-1 gene expression have not been defined. To address the relationship between the NF-kappaB pathway and MMP-1 gene activation in chondrocytes, primary cultured human articular chondrocyte cultures (HAC) and SW-1353 cells were stimulated with IL-1beta over a 24-h time course and MMP-1, NF-kappaB1, NF-kappaB2 and RelA gene expression was assayed. IL-1beta-induced MMP-1 expression was comparable in HAC and SW-1353 cells both temporally and quantitatively. MMP-1 gene expression was mirrored by increases in NF-kappaB gene expression, and inhibition of NF-kappaB nuclear translocation with dominant-negative IkappaBalpha reduced IL-1beta-dependent MMP-1 gene expression. IL-1beta activated the NF-kappaB pathway in chondrocytes, both through phosphorylation and transient degradation of IkappaBalpha, as well as through sustained phosphorylation of RelA. Small inhibitory RNAs (siRNA) specific for RelA resulted in significant reduction of MMP-1 mRNA, whereas siRNA for NF-kappaB1 and NF-kappaB2 augmented IL-1beta-induced MMP-1 expression. Our data demonstrate that IL-1beta activation of the NF-kappaB pathway is required for IL-1beta induction of MMP-1 in chondrocytes and that RelA can work independently of NF-kappaB1 or NF-kappaB2 to activate this gene expression program.

Growth inhibition and apoptosis inducing mechanisms of curcumin on human ovarian cancer cell line A2780

To explore the growth inhibition effects and apoptosis inducing mechanisms of curcumin on human ovarian cancer cell line A2780. After treatment with 10 - 50 micromol/L curcumin for 6 - 24 h, the growth activity of A2780 cancer cells were studied by [4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) colorimetry. Cellular apoptosis was inspected by flow cytometery and acridine orange-ethidium bromide fluorescent staining methods. The fragmentation of cellular chromosome DNA was detected by DNA ladder, the ultrastructural change was observed under a transmission electron microscope, and the protein levels of nuclear factor-kappa B (NF-kappaB, P65) and cysteinyl aspartate specific protease-3 (Caspase-3) in ovarian cancer cells were measured by immunohistochemistry. After treatment with various concentrations of curcumin, the growth inhibition rates of cancer cells reached 62.05% - 89.24%, with sub-G(1) peaks appearing on histogram. Part of the cancer cells showed characteristic morphological changes of apoptosis under fluorescence and electron microscopes, and the rate of apoptosis was 21.5% - 33.5%. The protein expression of NF-kappaB was decreased, while that of Caspase-3 was increased in a time-dependent manner. Curcumin could significantly inhibit the growth of human ovarian cancer cells; inducing apoptosis through up-regulating Caspase-3 and down-regulating gene expression of NF-kappaB is probably one of its molecular mechanisms.

Differential expression of NF-κB pathway genes among peripheral T-cell lymphomas

Nuclear factor kappa B (NF-kappaB) is one important pathway in T-cell proliferation and survival. In a previously reported microarray study, we found NF-kappaB pathway genes differentially expressed between peripheral (PTCL) and lymphoblastic lymphomas. Here, we investigated the expression of NF-kappaB pathway genes using cDNA microarrays in a group of 62 PTCL and in reactive lymph nodes. We found two different subgroups of PTCL based on the expression of NF-kappaB pathway genes. One-third of PTCL showed clearly reduced expression of NF-kappaB genes, while the other group was characterized by high expression of these genes. This distinction was found among all T-cell lymphoma categories analyzed (PTCL unspecified, angioimmunoblastic, cutaneous and natural killer/T lymphomas) with the exception of anaplastic lymphomas (ALCL), which were characterized by reduced NF-kappaB expression in anaplastic cells. Quantitative RT-PCR and immunohistochemical analysis of NF-kappaB-p65 protein confirmed these differences among PTCL subgroups. Importantly, we found that differentiation between NF-kappaB-positive and -negative PTCL could be of clinical interest. The expression profile associated to reduced expression of NF-kappaB genes was significantly associated with shorter survival of patients and seems to be an independent prognostic factor in a multivariate analysis.

Treatment with an anti-CD14 monoclonal antibody delays and inhibits lipopolysaccharide-induced gene expression in humans in vivo.

CD14 is a receptor important for activation of cells by lipopolysaccharide (LPS). Treatment with the CD14 antibody IC14 was previously found to attenuate the release of proinflammatory cytokines and some chemokines into the circulation of healthy humans intravenously injected with LPS. To determine the role of circulating leukocytes in CD14-dependent gene expression, 16 healthy volunteers received LPS preceded by either IC14 or placebo. At different time points, mRNA was isolated from whole blood and gene expression was determined by multiplex ligation-dependent probe amplification (MLPA). LPS induced MIP-1alpha, MIP-1beta, IL-8, IL-1beta, and IL-1Ra mRNA production, which was delayed by 1 hr and reduced twofold by IC14 treatment. TNFR1 was unresponsive, whereas other investigated cytokines remained undetectable. Further, LPS showed differential effects on NFkappaB gene expression. LPS induced IkappaBalpha production, whereas p50 was unresponsive and p65 and p49/p100 remained undetectable. LPS induced IkappaBalpha expression was delayed (1 hr) and reduced by IC14. Gene expression profiles in blood cells corresponded poorly with observed changes in plasma levels. These data suggest that peripheral blood cells are of negligible importance in LPS-induced production of inflammatory mediators in vivo and that LPS may activate genes via a CD14-independent pathway that is slower and less efficient.

Aspirin inhibits Chlamydia pneumoniae-induced nuclear factor-kappa B activation, cytokine expression, and bacterial development in human endothelial cells.

Chlamydia pneumoniae has been associated with atherosclerosis. Infection of vascular endothelial cells with C pneumoniae increases the expression of proatherogenic cytokines mediated by nuclear factor (NF)-kappaB, a transcription factor. The present study was designed to test the effect of aspirin on C pneumoniae-induced NF-kappaB activation, interleukin expression, and bacterial development in cultured human endothelial cells. Aspirin, its metabolite salicylic acid, and 2 other unrelated NF-kappaB inhibitors showed a strong concentration-dependent inhibitory effect on chlamydial growth, indicated by the reduction of bacterial inclusions and the titer of infectious progeny. Involvement of the transcription factor NF-kappaB was confirmed by electrophoretic mobility shift assay and by transfection experiments with appropriate decoy oligodeoxynucleotides. Attenuation of the C pneumoniae-induced activation of NF-kappaB by aspirin also reduced the secretion of interleukin-6 and interleukin-8, indicating efficient inhibition of NF-kappaB gene expression. Reduction of chlamydial growth was not caused by apoptosis of the host cell, as determined by monitoring characteristic chromatin condensation. These data provide evidence that NF-kappaB-mediated gene activation represents a crucial step in the developmental cycle of C pneumoniae. Aspirin exerts an anti-chlamydial effect that is due to the inhibition of C pneumoniae-induced NF-kappaB activation, which might account for some of the cardioprotective activity of aspirin.

Increased gene expression in human promyeloid leukemia cells exposed to trans,trans-muconaldehyde, a hematotoxic benzene metabolite.

The hematotoxicity of benzene, a human leukemogen, has been postulated to be mediated by reactive metabolites and involve cell damage caused by reactive oxygen species. Because expression of the transcription factors AP-1 and NF-kappaB is sensitive to the redox state in eukaryotic cells, the DNA binding activity of AP-1 and NF-kappaB was examined in HL-60 promyeloid leukemia cells exposed to trans,trans-muconaldehyde, a microsomal hematotoxic metabolite of benzene. There was little AP-1 binding activity in nuclear extracts from control HL-60 cells based on electrophoretic mobility shift assays. Exposure to 0.1 microM MUC for 4 h resulted in significantly increased levels of nuclear protein with high sequence specificity for the consensus AP-1 sequence. In addition, electrophoretic mobility shift assays showed a strong increase in the binding of a factor to the NF-kappaB site. The latter was highest in nuclear extracts from HL-60 cells treated with 1.0 microM muconaldehyde and cultured for 4 h. Exposure of HL-60 cells to muconaldehyde resulted in an increase in c-fos and c-jun mRNA levels. Western blot analysis showed that the protein levels of c-jun increased in HL-60 cells treated with 1 microM muconaldehyde and cultured for 4-6 h and subsequently decreased gradually. Increased AP-1 binding was observed in bone marrow cells from B6C3F1 mice 2 h after administration of 440 mg/kg benzene. We suggest that increased gene expression of NF-kappaB and AP-1 binding activity and up-regulation of c-fos and c-jun may play a role in the mechanism of benzene leukemogenesis.