NF-κB Signaling Regulates Epstein–Barr Virus BamHI-Q-Driven EBNA1 Expression

Directory of Open Access Journals (Sweden)

Rob J. A. Verhoeven

2018-04-01

Full Text Available Epstein–Barr virus (EBV nuclear antigen 1 (EBNA1 is one of the few viral proteins expressed by EBV in nasopharyngeal carcinoma (NPC, most likely because of its essential role in maintaining the viral genome in EBV-infected cells. In NPC, EBNA1 expression is driven by the BamHI-Q promoter (Qp, which is regulated by both cellular and viral factors. We previously determined that the expression of another group of EBV transcripts, BamHI-A rightward transcripts (BARTs, is associated with constitutively activated nuclear factor-κB (NF-κB signaling in NPC cells. Here, we show that, like the EBV BART promoter, the EBV Qp also responds to NF-κB signaling. NF-κB p65, but not p50, can activate Qp in vitro, and NF-κB signaling regulates Qp-EBNA1 expression in NPC cells, as well as in other EBV-infected epithelial cells. The introduction of mutations in the putative NF-κB site reduced Qp activation by the NF-κB p65 subunit. Binding of p65 to Qp was shown by chromatin immunoprecipitation (ChIP analysis, while electrophoretic mobility shift assays (EMSAs demonstrated that p50 can also bind to Qp. Inhibition of NF-κB signaling by the IκB kinase inhibitor PS-1145 resulted in the downregulation of Qp-EBNA1 expression in C666-1 NPC cells. Since EBNA1 has been reported to block p65 activation by inhibiting IKKα/β through an unknown mechanism, we suggest that, in NPC, NF-κB signaling and EBNA1 may form a regulatory loop which supports EBV latent gene expression, while also limiting NF-κB activity. These findings emphasize the role of NF-κB signaling in the regulation of EBV latency in EBV-associated tumors.

NF-kappaB signaling: a tale of two pathways in skeletal myogenesis.

Science.gov (United States)

Bakkar, Nadine; Guttridge, Denis C

2010-04-01

NF-kappaB is a ubiquitiously expressed transcription factor that plays vital roles in innate immunity and other processes involving cellular survival, proliferation, and differentiation. Activation of NF-kappaB is controlled by an IkappaB kinase (IKK) complex that can direct either canonical (classical) NF-kappaB signaling by degrading the IkappaB inhibitor and releasing p65/p50 dimers to the nucleus, or causes p100 processing and nuclear translocation of RelB/p52 via a noncanonical (alternative) pathway. Under physiological conditions, NF-kappaB activity is transiently regulated, whereas constitutive activation of this transcription factor typically in the classical pathway is associated with a multitude of disease conditions, including those related to skeletal muscle. How NF-kappaB functions in muscle diseases is currently under intense investigation. Insight into this role of NF-kappaB may be gained by understanding at a more basic level how this transcription factor contributes to skeletal muscle cell differentiation. Recent data from knockout mice support that the classical NF-kappaB pathway functions as an inhibitor of skeletal myogenesis and muscle regeneration acting through multiple mechanisms. In contrast, alternative NF-kappaB signaling does not appear to be required for myofiber conversion, but instead functions in myotube homeostasis by regulating mitochondrial biogenesis. Additional knowledge of these signaling pathways in skeletal myogenesis should aid in the development of specific inhibitors that may be useful in treatments of muscle disorders.

Neuronal RING finger protein 11 (RNF11 regulates canonical NF-κB signaling

Directory of Open Access Journals (Sweden)

Pranski Elaine L

2012-04-01

Full Text Available Abstract Background The RING domain-containing protein RING finger protein 11 (RNF11 is a member of the A20 ubiquitin-editing protein complex and modulates peripheral NF-κB signaling. RNF11 is robustly expressed in neurons and colocalizes with a population of α-synuclein-positive Lewy bodies and neurites in Parkinson disease patients. The NF-κB pathway has an important role in the vertebrate nervous system, where the absence of NF-κB activity during development can result in learning and memory deficits, whereas chronic NF-κB activation is associated with persistent neuroinflammation. We examined the functional role of RNF11 with respect to canonical NF-κB signaling in neurons to gain understanding of the tight association of inflammatory pathways, including NF-κB, with the pathogenesis of neurodegenerative diseases. Methods and results Luciferase assays were employed to assess NF-κB activity under targeted short hairpin RNA (shRNA knockdown of RNF11 in human neuroblastoma cells and murine primary neurons, which suggested that RNF11 acts as a negative regulator of canonical neuronal NF-κB signaling. These results were further supported by analyses of p65 translocation to the nucleus following depletion of RNF11. Coimmunoprecipitation experiments indicated that RNF11 associates with members of the A20 ubiquitin-editing protein complex in neurons. Site-directed mutagenesis of the myristoylation domain, which is necessary for endosomal targeting of RNF11, altered the impact of RNF11 on NF-κB signaling and abrogated RNF11’s association with the A20 ubiquitin-editing protein complex. A partial effect on canonical NF-κB signaling and an association with the A20 ubiquitin-editing protein complex was observed with mutagenesis of the PPxY motif, a proline-rich region involved in Nedd4-like protein interactions. Last, shRNA-mediated reduction of RNF11 in neurons and neuronal cell lines elevated levels of monocyte chemoattractant protein 1 and

Chalepin: A Compound from Ruta angustifolia L. Pers Exhibits Cell Cycle Arrest at S phase, Suppresses Nuclear Factor-Kappa B (NF-κB) Pathway, Signal Transducer and Activation of Transcription 3 (STAT3) Phosphorylation and Extrinsic Apoptotic Pathway in Non-small Cell Lung Cancer Carcinoma (A549).

Science.gov (United States)

Richardson, Jaime Stella Moses; Aminudin, Norhaniza; Abd Malek, Sri Nurestri

2017-10-01

transducer and activation of transcription 3, and extrinsic apoptotic pathway and also its ability to arrest cell cycle in S phase. This compound was from the leaves of Ruta angustifolia L. Pers. It provides new insight on the ability of this plant in suppressing certain cancers, especially the nonsmall cell lung carcinoma according to this study. Abbreviations used: °C: Degree Celsius, ANOVA: Analysis of variance, ATCC: American Type Culture Collection, BCL-2: B-Cell CLL/Lymphoma 2, Bcl-xL: B-cell lymphoma extra-large, BH3: Bcl-2 homology 3, BID: BH3-interacting domain death agonist, BIR: Baculovirus inhibitor of apoptosis protein repeat, Caspases: Cysteinyl aspartate-specific proteases, CDK: Cyclin-dependent kinase, CO 2 : Carbon dioxide, CST: Cell signaling technologies, DISC: Death-inducing signaling complex, DMSO: Dimethyl sulfoxide, DNA: Deoxyribonucleic acid, DR4: Death receptor 4, DR5: Death receptor 5, E1a: Adenovirus early region 1A, ECL: Enhanced chemiluminescence, EDTA: Ethylenediaminetetraacetic acid, ELISA: Enzyme-linked immunosorbent assay, etc.: Etcetera, FADD: Fas-associated protein with death domain, FBS: Fetal bovine serum, FITC: Fluorescein isothiocyanate, G1: Gap 1, G2: Gap 2, HPLC: High-performance liquid chromatography, HRP: Horseradish peroxidase, IAPs: Inhibitor of apoptosis proteins, IC50: Inhibitory concentration at half maximal inhibitory, IKK-α: Inhibitor of nuclear factor kappa-B kinase subunit alpha, IKK-β: Inhibitor of nuclear factor kappa-B kinase subunit beta, IKK-γ: Inhibitor of nuclear factor kappa-B kinase subunit gamma, IKK: IκB kinase, IkBα: Nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha, m: Meter, M: Mitotic, mm: Millimeter, mRNA: Messenger ribonucleic acid, NaCl: Sodium chloride, NaVO4: Sodium orthovanadate, NEMO: NF-Kappa-B essential modulator, NF-κB: Nuclear factor kappa-light chain-enhancer of activated B cells, NSCLC: Nonsmall cell lung carcinoma, PBS: Phosphate buffered saline, PGE2

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

International Nuclear Information System (INIS)

Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming

2016-01-01

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

Energy Technology Data Exchange (ETDEWEB)

Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming, E-mail: zengshenming@gmail.com

2016-04-22

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

Magnesium isoglycyrrhizinate blocks fructose-induced hepatic NF-κB/NLRP3 inflammasome activation and lipid metabolism disorder.

Science.gov (United States)

Zhao, Xiao-Juan; Yang, Yan-Zi; Zheng, Yan-Jing; Wang, Shan-Chun; Gu, Hong-Mei; Pan, Ying; Wang, Shui-Juan; Xu, Hong-Jiang; Kong, Ling-Dong

2017-08-15

Magnesium isoglycyrrhizinate as a hepatoprotective agent possesses immune modulation and anti-inflammation, and treats liver diseases. But its effects on immunological-inflammatory and metabolic profiles for metabolic syndrome with liver injury and underlying potential mechanisms are not fully understood. In this study, magnesium isoglycyrrhizinate alleviated liver inflammation and lipid accumulation in fructose-fed rats with metabolic syndrome. It also suppressed hepatic inflammatory signaling activation by reducing protein levels of phosphorylation of nuclear factor-kappa B p65 (p-NF-κB p65), inhibitor of nuclear factor kappa-B kinase α/β (p-IKKα/β) and inhibitor of NF-κB α (p-IκBα) as well as nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC) and Caspase-1 in rats, being consistent with its reduction of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 levels. Furthermore, magnesium isoglycyrrhizinate modulated lipid metabolism-related genes characterized by up-regulating peroxisome proliferator-activated receptor-α (PPAR-α) and carnitine palmitoyl transferase-1 (CPT-1), and down-regulating sensor for fatty acids to control-1 (SREBP-1) and stearoyl-CoA desaturase 1 (SCD-1) in the liver of fructose-fed rats, resulting in the reduction of triglyceride and total cholesterol levels. These effective actions were further confirmed in fructose-exposed BRL-3A and HepG2 cells. The molecular mechanisms underpinning these observations suggest that magnesium isoglycyrrhizinate may inhibit NF-κB/NLRP3 inflammasome activation to reduce immunological-inflammatory response, which in turn may prevent liver lipid metabolic disorder and accumulation under high fructose condition. Thus, blockade of NF-κB/NLRP3 inflammasome activation and lipid metabolism disorder by magnesium isoglycyrrhizinate may be the potential therapeutic approach for improving fructose-induced liver injury with

CPT-11 activates NLRP3 inflammasome through JNK and NF-κB signalings

Energy Technology Data Exchange (ETDEWEB)

Li, Qian [Department of Oncology, The First Affiliated Hospital with Nanjing Medical University, 300, Guangzhou Road, Nanjing 210029 (China); Zhang, Xiong [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210046 (China); Wang, Weicheng; Li, LeLe [Department of Oncology, The First Affiliated Hospital with Nanjing Medical University, 300, Guangzhou Road, Nanjing 210029 (China); Xu, Qiang, E-mail: molpharm@163.com [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210046 (China); Wu, Xudong, E-mail: xudongwu@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210046 (China); Gu, Yanhong, E-mail: guluer@163.com [Department of Oncology, The First Affiliated Hospital with Nanjing Medical University, 300, Guangzhou Road, Nanjing 210029 (China)

2015-12-01

CPT-11 is widely used for cancer therapy as a chemotherapeutic agent. Despite its good efficacy, a large number of side effects appeared during decades of clinical application. Delayed diarrhea, at dose limiting toxicity, happens after 24 h of treatment and the rate of occurrence is up to 90%. Although many investments have been made on this negative impact, the real molecular mechanism of delayed diarrhea is poorly understood. In this study, we have discovered that CPT-11 promotes macrophage infiltration into intestinal tissues and activates the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome, resulting in a robust IL-1β response and colonic inflammation similar to DSS (dextran sodium sulfate) induced experimental colitis. CPT-11 plus LPS primed mouse bone marrow-derived macrophages (BMDMs) and human acute monocytic leukemia cells (THP-1 cells) staying in a highly activated status, showing increased caspase-1 activity and releasing great amounts of IL-1β and IL-18 as detected by ELISA and western blot. A further mechanism showed that JNK and NF-κB signaling pathways participated in inflammatory responses activated by CPT-11. These results prompted us to suggest that the NLRP3-IL-1β signaling pathway might play an important role in CPT11-induced colitis. Our findings provide a basis for developing novel strategies that improve clinical implications of CPT-11. - Highlights: • CPT-11 induced experimental colitis in vivo. • CPT-11 induced intestine injury and macrophage infiltration. • CPT-11 significantly elevated levels of macrophage derived inflammatory cytokines in mice intestines. • CPT-11 activated NLRP3 inflammasome in vitro and in vivo. • CPT-11 activated JNK and NF-κB signalings in THP-1 and BMDMs.

Src-family-tyrosine kinase Lyn is critical for TLR2-mediated NF-κB activation through the PI 3-kinase signaling pathway.

Science.gov (United States)

Toubiana, Julie; Rossi, Anne-Lise; Belaidouni, Nadia; Grimaldi, David; Pene, Frederic; Chafey, Philippe; Comba, Béatrice; Camoin, Luc; Bismuth, Georges; Claessens, Yann-Erick; Mira, Jean-Paul; Chiche, Jean-Daniel

2015-10-01

TLR2 has a prominent role in host defense against a wide variety of pathogens. Stimulation of TLR2 triggers MyD88-dependent signaling to induce NF-κB translocation, and activates a Rac1-PI 3-kinase dependent pathway that leads to transactivation of NF-κB through phosphorylation of the P65 NF-κB subunit. This transactivation pathway involves tyrosine phosphorylations. The role of the tyrosine kinases in TLR signaling is controversial, with discrepancies between studies using only chemical inhibitors and knockout mice. Here, we show the involvement of the tyrosine-kinase Lyn in TLR2-dependent activation of NF-κB in human cellular models, by using complementary inhibition strategies. Stimulation of TLR2 induces the formation of an activation cluster involving TLR2, CD14, PI 3-kinase and Lyn, and leads to the activation of AKT. Lyn-dependent phosphorylation of the p110 catalytic subunit of PI 3-kinase is essential to the control of PI 3-kinase biological activity upstream of AKT and thereby to the transactivation of NF-κB. Thus, Lyn kinase activity is crucial in TLR2-mediated activation of the innate immune response in human mononuclear cells. © The Author(s) 2015.

NF-κB signaling mechanisms in HTLV-1-induced adult T-cell leukemia/lymphoma.

Science.gov (United States)

Harhaj, Edward William; Giam, Chou-Zen

2018-05-03

The human T-cell leukemia virus type 1 (HTLV-1) is a complex deltaretrovirus linked to adult T-cell leukemia/lymphoma (ATLL), a fatal CD4+ malignancy in 3-5% of infected individuals. The HTLV-1 Tax regulatory protein plays indispensable roles in regulating viral gene expression and activating cellular signaling pathways that drive the proliferation and clonal expansion of T cells bearing HTLV-1 proviral integrations. Tax is a potent activator of NF-κB, a key signaling pathway that is essential for the survival and proliferation of HTLV-1 infected T cells. However, constitutive NF-κB activation by Tax also triggers a senescence response, suggesting the possibility that only T cells capable of overcoming NF-κB-induced senescence can selectively undergo clonal expansion after HTLV-1 infection. Tax expression is often silenced in the majority of ATLL due to genetic alterations in the tax gene or DNA hypermethylation of the 5'-LTR. Despite the loss of Tax, NF-κB activation remains persistently activated in ATLL due to somatic mutations in genes in the T/B-cell receptor (T/BCR) and NF-κB signaling pathways. In this review, we focus on the key events driving Tax-dependent and independent mechanisms of NF-κB activation during the multi-step process leading to ATLL. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

[NF-κB signaling pathways and the future perspectives of bone disease therapy using selective inhibitors of NF-κB].

Science.gov (United States)

Jimi, Eijiro; Fukushima, Hidefumi

2016-02-01

The transcriptional factor nuclear factor κB(NF-κB)regulates the expression of a wide variety of genes that are involved in immune and inflammatory responses, proliferation, and tumorigenesis. NF-κB consists of five members, such as p65(RelA), RelB, c-Rel, p50/p105(NF-κB1), and p52/p100(NF-κB2). There are two distinct NF-κB activation pathways, termed the classical and alternative NF-κB signaling pathways. Since mice lacking both p50 and p52 subunits developed typical osteopetrosis, due to total lack of osteoclasts, NF-κB is also important osteoclast differentiation. A selective NF-κB inhibitor blocked receptor activator of NF-κB ligand(RANKL)-induced osteoclastogenesis both in vitro and in vivo. Recent findings have shown that inactivation of NF-κB enhances osteoblast differentiation in vitro and bone formation in vivo. NF-κB is constitutively activated in many cancers including oral squamous cell carcinoma(OSCC), and is involved in the invasive characteristics of OSCC. A selective NF-κB inhibitor also prevented jaw bone destruction by OSCC by reduced osteoclast numbers in animal model. Thus the inhibition of NF-κB might useful for the treatment of bone diseases, such as arthritis, osteoporosis, periodontitis, and bone invasion by OSCC by inhibiting bone resorption and by stimulating bone formation.

Bmi-1 promotes the aggressiveness of glioma via activating the NF-kappaB/MMP-9 signaling pathway

International Nuclear Information System (INIS)

Jiang, Lili; Wu, Jueheng; Yang, Yi; Liu, Liping; Song, Libing; Li, Jun; Li, Mengfeng

2012-01-01

The prognosis of human glioma is poor, and the highly invasive nature of the disease represents a major impediment to current therapeutic modalities. The oncoprotein B-cell-specific Moloney murine leukemia virus integration site 1 protein (Bmi-1) has been linked to the development and progression of glioma; however, the biological role of Bmi-1 in the invasion of glioma remains unclear. A172 and LN229 glioma cells were engineered to overexpress Bmi-1 via stable transfection or to be silenced for Bmi-1 expression using RNA interfering method. Migration and invasiveness of the engineered cells were assessed using wound healing assay, Transwell migration assay, Transwell matrix penetration assay and 3-D spheroid invasion assay. MMP-9 expression and activity were measured using real-time PCR, ELISA and the gelatin zymography methods. Expression of NF-kappaB target genes was quantified using real-time PCR. NF-kappaB transcriptional activity was assessed using an NF-kappaB luciferase reporter system. Expression of Bmi-1 and MMP-9 in clinical specimens was analyzed using immunohistochemical assay. Ectopic overexpression of Bmi-1 dramatically increased, whereas knockdown of endogenous Bmi-1 reduced, the invasiveness and migration of glioma cells. NF-kappaB transcriptional activity and MMP-9 expression and activity were significantly increased in Bmi-1-overexpressing but reduced in Bmi-1-silenced cells. The reporter luciferase activity driven by MMP-9 promoter in Bmi-1-overexpressing cells was dependent on the presence of a functional NF-kappaB binding site, and blockade of NF-kappaB signaling inhibited the upregulation of MMP-9 in Bmi-1 overexpressing cells. Furthermore, expression of Bmi-1 correlated with NF-kappaB nuclear translocation as well as MMP-9 expression in clinical glioma samples. Bmi-1 may play an important role in the development of aggressive phenotype of glioma via activating the NF-kappaB/MMP-9 pathway and therefore might represent a novel therapeutic

Bmi-1 promotes the aggressiveness of glioma via activating the NF-kappaB/MMP-9 signaling pathway

Directory of Open Access Journals (Sweden)

Jiang Lili

2012-09-01

Full Text Available Abstract Background The prognosis of human glioma is poor, and the highly invasive nature of the disease represents a major impediment to current therapeutic modalities. The oncoprotein B-cell-specific Moloney murine leukemia virus integration site 1 protein (Bmi-1 has been linked to the development and progression of glioma; however, the biological role of Bmi-1 in the invasion of glioma remains unclear. Methods A172 and LN229 glioma cells were engineered to overexpress Bmi-1 via stable transfection or to be silenced for Bmi-1 expression using RNA interfering method. Migration and invasiveness of the engineered cells were assessed using wound healing assay, Transwell migration assay, Transwell matrix penetration assay and 3-D spheroid invasion assay. MMP-9 expression and activity were measured using real-time PCR, ELISA and the gelatin zymography methods. Expression of NF-kappaB target genes was quantified using real-time PCR. NF-kappaB transcriptional activity was assessed using an NF-kappaB luciferase reporter system. Expression of Bmi-1 and MMP-9 in clinical specimens was analyzed using immunohistochemical assay. Results Ectopic overexpression of Bmi-1 dramatically increased, whereas knockdown of endogenous Bmi-1 reduced, the invasiveness and migration of glioma cells. NF-kappaB transcriptional activity and MMP-9 expression and activity were significantly increased in Bmi-1-overexpressing but reduced in Bmi-1-silenced cells. The reporter luciferase activity driven by MMP-9 promoter in Bmi-1-overexpressing cells was dependent on the presence of a functional NF-kappaB binding site, and blockade of NF-kappaB signaling inhibited the upregulation of MMP-9 in Bmi-1 overexpressing cells. Furthermore, expression of Bmi-1 correlated with NF-kappaB nuclear translocation as well as MMP-9 expression in clinical glioma samples. Conclusions Bmi-1 may play an important role in the development of aggressive phenotype of glioma via activating the NF

NF-kappaB mediates FGF signal regulation of msx-1 expression.

Science.gov (United States)

Bushdid, P B; Chen, C L; Brantley, D M; Yull, F; Raghow, R; Kerr, L D; Barnett, J V

2001-09-01

The nuclear factor-kappaB (NF-kappaB) family of transcription factors is involved in proliferation, differentiation, and apoptosis in a stage- and cell-dependent manner. Recent evidence has shown that NF-kappaB activity is necessary for both chicken and mouse limb development. We report here that the NF-kappaB family member c-rel and the homeodomain gene msx-1 have partially overlapping expression patterns in the developing chick limb. In addition, inhibition of NF-kappaB activity resulted in a decrease in msx-1 mRNA expression. Sequence analysis of the msx-1 promoter revealed three potential kappaB-binding sites similar to the interferon-gamma (IFN-gamma) kappaB-binding site. These sites bound to c-Rel, as shown by electrophoretic mobility shift assay (EMSA). Furthermore, inhibition of NF-kappaB activity significantly reduced transactivation of the msx-1 promoter in response to FGF-2/-4, known stimulators of msx-1 expression. These results suggest that NF-kappaB mediates the FGF-2/-4 signal regulation of msx-1 gene expression. Copyright 2001 Academic Press.

Pedilanthus tithymaloides Inhibits HSV Infection by Modulating NF-κB Signaling.

Directory of Open Access Journals (Sweden)

Durbadal Ojha

Full Text Available Pedilanthus tithymaloides (PT, a widely used ethnomedicinal plant, has been employed to treat a number of skin conditions. To extend its utility and to fully exploit its medicinal potential, we have evaluated the in vitro antiviral activity of a methanolic extract of PT leaves and its isolated compounds against Herpes Simplex Virus type 2 (HSV-2. Bioactivity-guided studies revealed that the extract and one of its constituents, luteolin, had potent antiviral activity against wild-type and clinical isolates of HSV-2 (EC50 48.5-52.6 and 22.4-27.5 μg/ml, respectively, with nearly complete inhibition at 86.5-101.8 and 40.2-49.6 μg/ml, respectively. The inhibitory effect was significant (p<0.001 when the drug was added 2 h prior to infection, and was effective up to 4 h post-infection. As viral replication requires NF-κB activation, we examined whether the observed extract-induced inhibition of HSV-2 was related to NF-κB inhibition. Interestingly, we observed that treatment of HSV-2-infected cells with extract or luteolin suppressed NF-κB activation. Although NF-κB, JNK and MAPK activation was compromised during HSV replication, neither the extract nor luteolin affected HSV-2-induced JNK1/2 and MAPK activation. Moreover, the PT leaf extract and luteolin potently down-regulated the expression of tumor necrosis factor (TNF-α, Interleukin (IL-1β, IL-6, NO and iNOS and the production of gamma interferon (IFN-γ, which are directly involved in controlling the NF-κB signaling pathway. Thus, our results indicate that both PT leaf extract and luteolin modulate the NF-κB signaling pathway, resulting in the inhibition of HSV-2 replication.

TLR4 activates NF-{kappa}B in human ovarian granulosa tumor cells

Energy Technology Data Exchange (ETDEWEB)

Woods, Dori C., E-mail: dwoods2@partners.org [Vincent Center for Reproductive Biology, Vincent Obstetrics and Gynecology Service, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114 (United States); White, Yvonne A.R. [Vincent Center for Reproductive Biology, Vincent Obstetrics and Gynecology Service, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114 (United States); Dau, Caroline [University of California, San Francisco, School of Dentistry, San Francisco, CA 94143 (United States); Johnson, A.L. [Center for Reproductive Biology and Health, The Pennsylvania State University, University Park, PA 16802 (United States)

2011-06-17

Highlights: {yields} TLR4 is expressed in human ovarian granulosa tumor cells. {yields} Acting through TLR4, LPS and HSP60 induce a NF{kappa}B signaling cascade in human ovarian granulosa tumor cells. {yields} NF{kappa}B activation or inhibition did not alter chemosensitivity to TRAIL or cisplatin. -- Abstract: Previous studies have demonstrated expression of Toll-like receptors (TLRs) in the surface epithelium of normal ovaries (OSE) and in epithelial ovarian tumors. Most notably, OSE-derived cancers express TLR4, which activates the nuclear factor-kappa B (NF-{kappa}B) signaling cascade as a mediator of inflammatory response. Currently, there is considerable interest in elucidating the role of TLR-mediated signaling in cancers. Nevertheless, the expression of TLRs in granulosa cell tumors (GCTs) of the ovary, and the extent to which GCT expression of TLRs may influence cell-signaling pathways and/or modulate the efficacy of chemotherapeutics, has yet to be determined. In the present study, human GCT lines (COV434 and KGN) were utilized to evaluate expression of functional TLR4. TLR4 is expressed in GCT cell lines and ligation of TLR4 with bacterial lipopolysaccharide (LPS) led to I{kappa}B degradation and activation of NF-{kappa}B. NF-{kappa}B activation was confirmed by nuclear localization of NF-{kappa}B p65 following treatment with LPS and the naturally occurring ligand, HSP60. Notably, immunoneutralization of TLR4 blocked nuclear localization, and inhibition of NF-{kappa}B signaling attenuated LPS-induced TNF{alpha} plus increased doubling time in both cell lines. Contradictory to reports using human OSE cell lines, inhibition of NF-{kappa}B signaling failed to sensitize GCT lines to TRAIL or cisplatin. In summary, findings herein are the first to demonstrate a functional TLR-signaling pathway specifically in GCTs, and indicate that in contrast to OSE-derived cancers, inhibition of NF-{kappa}B does not sensitize GCTs to TRAIL or cisplatin.

MicroRNA Roles in the NF-κB Signaling Pathway during Viral Infections

Directory of Open Access Journals (Sweden)

Zeqian Gao

2014-01-01

Full Text Available NF-κB signaling network is a crucial component of innate immunity. miRNAs are a subtype of small noncoding RNAs, involved in regulation of gene expression at the posttranscriptional level. Increasing evidence has emerged that miRNAs play an important role in regulation of NF-κB signaling pathway during viral infections. Both host and viral miRNAs are attributed to modulation of NF-κB activity, thus affecting viral infection and clearance. Understandings of the mechanisms of these miRNAs will open a direction for development of novel antivirus drugs.

Phosphodiesterase inhibitors suppress Lactobacillus casei cell-wall-induced NF-κB and MAPK activations and cell proliferation through protein kinase A--or exchange protein activated by cAMP-dependent signal pathway.

Science.gov (United States)

Saito, Takekatsu; Sugimoto, Naotoshi; Ohta, Kunio; Shimizu, Tohru; Ohtani, Kaori; Nakayama, Yuko; Nakamura, Taichi; Hitomi, Yashiaki; Nakamura, Hiroyuki; Koizumi, Shoichi; Yachie, Akihiro

2012-01-01

Specific strains of Lactobacillus have been found to be beneficial in treating some types of diarrhea and vaginosis. However, a high mortality rate results from underlying immunosuppressive conditions in patients with Lactobacillus casei bacteremia. Cyclic AMP (cAMP) is a small second messenger molecule that mediates signal transduction. The onset and progression of inflammatory responses are sensitive to changes in steady-state cAMP levels. L. casei cell wall extract (LCWE) develops arteritis in mice through Toll-like receptor-2 signaling. The purpose of this study was to investigate whether intracellular cAMP affects LCWE-induced pathological signaling. LCWE was shown to induce phosphorylation of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and cell proliferation in mice fibroblast cells. Theophylline and phosphodiesterase inhibitor increased intracellular cAMP and inhibited LCWE-induced cell proliferation as well as phosphorylation of NF-κB and MAPK. Protein kinase A inhibitor H89 prevented cAMP-induced MAPK inhibition, but not cAMP-induced NF-κB inhibition. An exchange protein activated by cAMP (Epac) agonist inhibited NF-κB activation but not MAPK activation. These results indicate that an increase in intracellular cAMP prevents LCWE induction of pathological signaling pathways dependent on PKA and Epac signaling.

Withaferin A disrupts ubiquitin-based NEMO reorganization induced by canonical NF-κB signaling

Energy Technology Data Exchange (ETDEWEB)

Jackson, Shawn S. [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Medical Scientist Training Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Cellular and Molecular Biology Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Oberley, Christopher [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Hooper, Christopher P. [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Cellular and Molecular Biology Program, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Grindle, Kreg [Department of Medicine, Division of Hematology and Oncology, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); Wuerzberger-Davis, Shelly [McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, 6159 Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, WI 53705 (United States); Wolff, Jared [Department of Medicine, Division of Hematology and Oncology, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705 (United States); and others

2015-02-01

The NF-κB family of transcription factors regulates numerous cellular processes, including cell proliferation and survival responses. The constitutive activation of NF-κB has also emerged as an important oncogenic driver in many malignancies, such as activated B-cell like diffuse large B cell lymphoma, among others. In this study, we investigated the impact and mechanisms of action of Withaferin A, a naturally produced steroidal lactone, against both signal-inducible as well as constitutive NF-κB activities. We found that Withaferin A is a robust inhibitor of canonical and constitutive NF-κB activities, leading to apoptosis of certain lymphoma lines. In the canonical pathway induced by TNF, Withaferin A did not disrupt RIP1 polyubiquitination or NEMO–IKKβ interaction and was a poor direct IKKβ inhibitor, but prevented the formation of TNF-induced NEMO foci which colocalized with TNF ligand. While GFP-NEMO efficiently formed TNF-induced foci, a GFP-NEMO{sup Y308S} mutant that is defective in binding to polyubiquitin chains did not form foci. Our study reveals that Withaferin A is a novel type of IKK inhibitor which acts by disrupting NEMO reorganization into ubiquitin-based signaling structures in vivo. - Highlights: • Withaferin A, a NF-κB inhibitor, disrupts signaling induced NEMO localization, a novel point of inhibition. • NEMO can be localized to distinct signaling foci after treatment with TNF. • ABC-type DLCBL cells can be sensitized to apoptosis after treatment with Withaferin A.

JANEX-1, a JAK3 inhibitor, protects pancreatic islets from cytokine toxicity through downregulation of NF-{kappa}B activation and the JAK/STAT pathway

Energy Technology Data Exchange (ETDEWEB)

Lv, Na; Kim, Eun-Kyung; Song, Mi-Young [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Choi, Ha-Na; Moon, Woo Sung [Department of Pathology, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Sung-Joo [Department of Herbology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Park, Jin-Woo [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kwon, Kang-Beom, E-mail: desson@wonkwang.ac.kr [Department of Physiology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Park, Byung-Hyun, E-mail: bhpark@chonbuk.ac.kr [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

2009-07-15

JANEX-1/WHI-P131, a selective Janus kinase 3 (JAK3) inhibitor, has been shown to delay the onset of diabetes in the NOD mouse model. However, the molecular mechanism by which JANEX-1 protects pancreatic {beta}-cells is unknown. In the current study, we investigated the role of JANEX-1 on interleukin (IL)-1{beta} and interferon (IFN)-{gamma}-induced {beta}-cell damage using isolated islets. JANEX-1-pretreated islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced inducible form of NO synthase (iNOS) expression, and decreased islet destruction. The molecular mechanism by which JANEX-1 inhibits iNOS expression was mediated through suppression of the nuclear factor {kappa}B (NF-{kappa}B) and JAK/signal transducer and activator of transcription (STAT) pathways. Islets treated with the cytokines downregulated the protein levels of suppressor of cytokine signaling (SOCS)-1 and SOCS-3, but pretreatment with JANEX-1 attenuated these decreases. Additionally, islets from JAK3{sup -/-} mice were more resistant to cytokine toxicity than islets from control mice. These results demonstrate that JANEX-1 protects {beta}-cells from cytokine toxicity through suppression of the NF-{kappa}B and JAK/STAT pathways and upregulation of SOCS proteins, suggesting that JANEX-1 may be used to preserve functional {beta}-cell mass.

PHF20 regulates NF-κB signalling by disrupting recruitment of PP2A to p65

Science.gov (United States)

Zhang, Tiejun; Park, Kyeong Ah; Li, Yuwen; Byun, Hee Sun; Jeon, Juhee; Lee, Yoonjung; Hong, Jang Hee; Kim, Jin Man; Huang, Song-Mei; Choi, Seung-Won; Kim, Sun-Hwan; Sohn, Kyung-Cheol; Ro, Hyunju; Lee, Ji Hoon; Lu, Tao; Stark, George R.; Shen, Han-Ming; Liu, Zheng-gang; Park, Jongsun; Hur, Gang Min

2014-01-01

Constitutive NF-κB activation in cancer cells is caused by defects in the signalling network responsible for terminating the NF-κB response. Here we report that plant homeodomain finger protein 20 maintains NF-κB in an active state in the nucleus by inhibiting the interaction between PP2A and p65. We show that plant homeodomain finger protein 20 induces canonical NF-κB signalling by increasing the DNA-binding activity of NF-κB subunit p65. In plant homeodomain finger protein 20-overexpressing cells, the termination of tumour necrosis factor-induced p65 phosphorylation is impaired whereas upstream signalling events triggered by tumour necrosis factor are unaffected. This effect strictly depends on the interaction between plant homeodomain finger protein 20 and methylated lysine residues of p65, which hinders recruitment of PP2A to p65, thereby maintaining p65 in a phosphorylated state. We further show that plant homeodomain finger protein 20 levels correlate with p65 phosphorylation levels in human glioma specimens. Our work identifies plant homeodomain finger protein 20 as a novel regulator of NF-κB activation and suggests that elevated expression of plant homeodomain finger protein 20 may drive constitutive NF-κB activation in some cancers. PMID:23797602

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

Science.gov (United States)

Song, Ji-Hye; Kang, Hee-Bum; Park, Seung-Ho; Jeong, Ji-Hoon; Park, Jeongjin; You, Yanghee; Lee, Yoo-Hyun; Lee, Jeongmin; Kim, Eungpil; Choi, Kyung-Chul; Jun, Woojin

2017-12-01

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

Effects of Qingshen Granules on the Oxidative Stress-NF/kB Signal Pathway in Unilateral Ureteral Obstruction Rats.

Science.gov (United States)

Jin, Hua; Wang, Yiping; Wang, Dong; Zhang, Lei

2018-01-01

Background . The activation of NF-kappa B (NF/kB) signaling pathway plays an important role in the process of epithelial-mesenchymal transition (EMT) and renal interstitial fibrosis (RIF) in renal tubules. The process of oxidative stress reaction in kidney is via excessive reactive oxygen species (ROS) production to activate NF/kB signaling pathway. Qingshen Granule (QSG) is an effective Chinese formula utilized to treat chronic renal failure. Previous studies confirmed that QSG could inhibit RIF in unilateral ureteral obstruction (UUO) rats. In this study, we used UUO rats to investigate the effects of QSG on oxidative stress and the activation of NF/kB signaling. Seventy male Sprague-Dawley (SD) rats were randomly divided into a sham group, UUO model group, Qingshen Granules (QSG) high-dose, medium-dose, and low-dose groups, PDTC group, and candesartan group (10 rats in each group). Our study demonstrated that oxidative stress-NF/kB signal pathway contributed to the formation of UUO renal interstitial fibrosis. QSG may protect against RIF by inhibiting the oxidative stress-NF/kB signal pathway, reducing inflammation, and improving renal tubular EMT.

Activation of AMP-activated protein kinase by kainic acid mediates brain-derived neurotrophic factor expression through a NF-kappaB dependent mechanism in C6 glioma cells

International Nuclear Information System (INIS)

Yoon, Hana; Oh, Young Taek; Lee, Jung Yeon; Choi, Ji Hyun; Lee, Ju Hie; Baik, Hyung Hwan; Kim, Sung Soo; Choe, Wonchae; Yoon, Kyung-Sik; Ha, Joohun; Kang, Insug

2008-01-01

AMP-activated protein kinase (AMPK) is a key regulator of energy homeostasis. Kainic acid (KA), a prototype excitotoxin is known to induce brain-derived neurotrophic factor (BDNF) in brain. In this study, we examined the role of AMPK in KA-induced BDNF expression in C6 glioma cells. We showed that KA and KA receptor agonist induced activation of AMPK and KA-induced AMPK activation was blocked by inhibition of Ca 2+ /calmodulin-dependent protein kinase kinase (CaMKK) β. We then showed that inhibition of AMPK by compound C, a selective inhibitor of AMPK, or small interfering RNA of AMPKα1 blocked KA-induced BDNF mRNA and protein expression. Inhibition of AMPK blocked KA-induced phosphorylation of CaMKII and I kappaB kinase (IKK) in C6 cells. Finally, we showed that inhibition of AMPK reduced DNA binding and transcriptional activation of nuclear factor-kappaB (NF-κB) in KA-treated cells. These results suggest that AMPK mediates KA-induced BDNF expression by regulating NF-κB activation

Protein kinase Cη activates NF-κB in response to camptothecin-induced DNA damage

International Nuclear Information System (INIS)

Raveh-Amit, Hadas; Hai, Naama; Rotem-Dai, Noa; Shahaf, Galit; Gopas, Jacob; Livneh, Etta

2011-01-01

Highlights: → Protein kinase C-eta (PKCη) is an upstream regulator of the NF-κB signaling pathway. → PKCη activates NF-κB in non-stressed conditions and in response to DNA damage. → PKCη regulates NF-κB by activating IκB kinase (IKK) and inducing IκB degradation. -- Abstract: The nuclear factor κB (NF-κB) family of transcription factors participates in the regulation of genes involved in innate- and adaptive-immune responses, cell death and inflammation. The involvement of the Protein kinase C (PKC) family in the regulation of NF-κB in inflammation and immune-related signaling has been extensively studied. However, not much is known on the role of PKC in NF-κB regulation in response to DNA damage. Here we demonstrate for the first time that PKC-eta (PKCη) regulates NF-κB upstream signaling by activating the IκB kinase (IKK) and the degradation of IκB. Furthermore, PKCη enhances the nuclear translocation and transactivation of NF-κB under non-stressed conditions and in response to the anticancer drug camptothecin. We and others have previously shown that PKCη confers protection against DNA damage-induced apoptosis. Our present study suggests that PKCη is involved in NF-κB signaling leading to drug resistance.

Immune Regulation of RAW264.7 Cells In Vitro by Flavonoids from Astragalus complanatus via Activating the NF-κB Signalling Pathway

Directory of Open Access Journals (Sweden)

Yu Li

2018-01-01

Full Text Available The current study aimed at investigating the effects of flavonoids from Astragalus complanatus (FAC on the proliferation, the contents, and gene expression levels of cytokines, secretion of surface stimulating factors, cell cycle, and the expression level of the NF-κB signalling pathway in RAW264.7 cells. Our results revealed that compared with control group, the contents of IL-6, IL-1β, TNF-α, and NO and the mRNA expression levels of IL-6, IL-1β, TNF-α, and iNOS in FAC-treated groups significantly increased (p<0.01. Moreover, FAC induced macrophage activation to release the above-mentioned mediators partly involved in NF-κB/MAPK signalling pathways. Therefore, FAC regulates immune function in RAW264.7 cells via activating the NF-κB signalling pathway. FAC could be applicable for agriculture, drug research, and food industry as a potent immune-modulatory agent.

Targeting loss of the Hippo signaling pathway in NF2-deficient papillary kidney cancers

Science.gov (United States)

Ricketts, Christopher J.; Wei, Darmood; Yang, Youfeng; Baranes, Sarah M.; Gibbs, Benjamin K.; Ohanjanian, Lernik; Spencer Krane, L.; Scroggins, Bradley T.; Keith Killian, J.; Wei, Ming-Hui; Kijima, Toshiki; Meltzer, Paul S.; Citrin, Deborah E.; Neckers, Len; Vocke, Cathy D.; Marston Linehan, W.

2018-01-01

Papillary renal cell carcinomas (PRCC) are a histologically and genetically heterogeneous group of tumors that represent 15–20% of all kidney neoplasms and may require diverse therapeutic approaches. Alteration of the NF2 tumor suppressor gene, encoding a key regulator of the Hippo signaling pathway, is observed in 22.5% of PRCC. The Hippo signaling pathway controls cell proliferation by regulating the transcriptional activity of Yes-Associated Protein, YAP1. Loss of NF2 results in aberrant YAP1 activation. The Src family kinase member Yes also regulates YAP1 transcriptional activity. This study investigated the importance of YAP and Yes activity in three NF2-deficient PRCC cell lines. NF2-deficency correlated with increased expression of YAP1 transcriptional targets and siRNA-based knockdown of YAP1 and Yes1 downregulated this pathway and dramatically reduced cell viability. Dasatinib and saracatinib have potent inhibitory effects on Yes and treatment with either resulted in downregulation of YAP1 transcription targets, reduced cell viability, and G0-G1 cell cycle arrest. Xenograft models for NF2-deficient PRCC also demonstrated reduced tumor growth in response to dasatinib. Thus, inhibiting Yes and the subsequent transcriptional activity of YAP1 had a substantial anti-tumor cell effect both in vitro and in vivo and may provide a viable therapeutic approach for patients with NF2-deficient PRCC. PMID:29535838

The role of NF-κB signaling in the maintenance of pluripotency of human induced pluripotent stem cells.

Directory of Open Access Journals (Sweden)

Osamu Takase

Full Text Available NF-κB signaling plays an essential role in maintaining the undifferentiated state of embryonic stem (ES cells. However, opposing roles of NF-κB have been reported in mouse and human ES cells, and the role of NF-κB in human induced pluripotent stem (iPS cells has not yet been clarified. Here, we report the role of NF-κB signaling in maintaining the undifferentiated state of human iPS cells. Compared with differentiated cells, undifferentiated human iPS cells showed an augmentation of NF-κB activity. During differentiation induced by the removal of feeder cells and FGF2, we observed a reduction in NF-κB activity, the expression of the undifferentiation markers Oct3/4 and Nanog, and the up-regulation of the differentiated markers WT-1 and Pax-2. The specific knockdown of NF-κB signaling using p65 siRNA also reduced the expression of Oct3/4 and Nanog and up-regulated WT-1 and Pax-2 but did not change the ES-like colony formation. Our results show that the augmentation of NF-κB signaling maintains the undifferentiated state of human iPS and suggest the importance of this signaling pathway in maintenance of human iPS cells.

Sargahydroquinoic acid inhibits TNFα-induced AP-1 and NF-κB signaling in HaCaT cells through PPARα activation

Energy Technology Data Exchange (ETDEWEB)

Jeon, Youngsic; Jung, Yujung; Kim, Min Cheol; Kwon, Hak Cheol [Natural Medicine Center, KIST Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Kang, Ki Sung [College of Korean Medicine, Gachon University, Seongnam 461-701 (Korea, Republic of); Kim, Yong Kee, E-mail: yksnbk@sm.ac.kr [College of Pharmacy, Sookmyung Women’s University, Seoul 140-742 (Korea, Republic of); Kim, Su-Nam, E-mail: snkim@kist.re.kr [Natural Medicine Center, KIST Gangneung Institute, Gangneung 210-340 (Korea, Republic of)

2014-08-08

Highlights: • SHQA increases PPARα/γ transactivation and inhibits MMP-2/-9 expression. • SHQA inhibits TNFα-induced AP-1 and MAPK signaling. • SHQA inhibits TNFα-induced p65 translocation and IκBα phosphorylation. • SHQA inhibits TNFα-induced AP-1 and NF-κB signaling via PPARα. - Abstract: Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors and expressed in various cell types in the skin, including keratinocytes, fibroblasts and infiltrating immune cells. Thus, their ligands are targets for the treatment of various skin disorders, such as photo-aging and chronological aging of skin. Intensive studies have revealed that PPARα/γ functions in photo-aging and age-related inflammation by regulating matrix metalloproteinases (MMPs) via activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB). However, the detailed mechanism of PPARα/γ’s role in skin aging has not yet been elucidated. In this study, we confirmed that sargahydroquinoic acid (SHQA) as a PPARα/γ ligand significantly decreased Tumor Necrosis Factor-alpha (TNFα)-induced MMP-2/-9 expression by downregulating TNFα-induced transcription factors, subsequently reducing IκBα degradation and blocking NF-κB p65 nuclear translocation in HaCaT human epidermal keratinocyte cells. Treatment of cells with SHQA and GW6471 (PPARα antagonist) not bisphenol A diglycidyl ether (PPARγ antagonists), reversed the effect on TNFα-induced inflammatory signaling pathway activation. Taken together, our data suggest that SHQA inhibit TNFα-induced MMP-2/-9 expression and age-related inflammation by suppressing AP-1 and NF-κB pathway via PPARα.

The TRIF-dependent signaling pathway is not required for acute cerebral ischemia/reperfusion injury in mice

Energy Technology Data Exchange (ETDEWEB)

Hua, Fang, E-mail: fhua2@emory.edu [Department of Emergency Medicine, Brain Research Laboratory, Emory University School of Medicine, 1365B Clifton Road, Suite 5100, Atlanta, GA 30322 (United States); Wang, Jun; Sayeed, Iqbal; Ishrat, Tauheed; Atif, Fahim; Stein, Donald G. [Department of Emergency Medicine, Brain Research Laboratory, Emory University School of Medicine, 1365B Clifton Road, Suite 5100, Atlanta, GA 30322 (United States)

2009-12-18

TIR domain-containing adaptor protein (TRIF) is an adaptor protein in Toll-like receptor (TLR) signaling pathways. Activation of TRIF leads to the activation of interferon regulatory factor 3 (IRF3) and nuclear factor kappa B (NF-{kappa}B). While studies have shown that TLRs are implicated in cerebral ischemia/reperfusion (I/R) injury and in neuroprotection against ischemia afforded by preconditioning, little is known about TRIF's role in the pathological process following cerebral I/R. The present study investigated the role that TRIF may play in acute cerebral I/R injury. In a mouse model of cerebral I/R induced by transient middle cerebral artery occlusion, we examined the activation of NF-{kappa}B and IRF3 signaling in ischemic cerebral tissue using ELISA and Western blots. Neurological function and cerebral infarct size were also evaluated 24 h after cerebral I/R. NF-{kappa}B activity and phosphorylation of the inhibitor of kappa B (I{kappa}B{alpha}) increased in ischemic brains, but IRF3, inhibitor of {kappa}B kinase complex-{epsilon} (IKK{epsilon}), and TANK-binding kinase1 (TBK1) were not activated after cerebral I/R in wild-type (WT) mice. Interestingly, TRIF deficit did not inhibit NF-{kappa}B activity or p-I{kappa}B{alpha} induced by cerebral I/R. Moreover, although cerebral I/R induced neurological and functional impairments and brain infarction in WT mice, the deficits were not improved and brain infarct size was not reduced in TRIF knockout mice compared to WT mice. Our results demonstrate that the TRIF-dependent signaling pathway is not required for the activation of NF-{kappa}B signaling and brain injury after acute cerebral I/R.

Low-Dose Radiation Promotes Dendritic Cell Migration and IL-12 Production via the ATM/NF-KappaB Pathway.

Science.gov (United States)

Yu, Nan; Wang, Sinian; Song, Xiujun; Gao, Ling; Li, Wei; Yu, Huijie; Zhou, Chuanchuan; Wang, Zhenxia; Li, Fengsheng; Jiang, Qisheng

2018-04-01

For dendritic cells (DCs) to initiate an immune response, their ability to migrate and to produce interleukin-12 (IL-12) is crucial. It has been previously shown that low-dose radiation (LDR) promoted IL-12 production by DCs, resulting in increased DC activity that contributed to LDR hormesis in the immune system. However, the molecular mechanism of LDR-induced IL-12 production, as well as the effect of LDR on DC migration capacity require further elucidation. Using the JAWSII immortalized mouse dendritic cell line, we showed that in vitro X-ray irradiation (0.2 Gy) of DCs significantly increased DC migration and IL-12 production, and upregulated CCR7. The neutralizing antibody against CCR7 has been shown to abolish LDR-enhanced DC migration, demonstrating that CCR7 mediates LDR-promoting DC migration. We identified nuclear factor kappaB (NF-κB) as the central signaling pathway that mediated LDR-enhanced expression of IL-12 and CCR7 based on findings that 0.2 Gy X-ray irradiation activated NF-κB, showing increased nuclear p65 translocation and NF-κB DNA-binding activity, while an NF-κB inhibitor blocked LDR-enhanced expression of IL-12 and CCR7, as well as DC migration. Finally, we demonstrated that 0.2 Gy X-ray irradiation promoted ATM phosphorylation and reactive oxygen species generation; however, only the ATM inhibitor abolished the LDR-induced NF-κB-mediated expression of IL-12 and CCR7. Altogether, our data show that exposure to LDR resulted in a hormetic effect on DCs regarding CCR7-mediated migration and IL-12 production by activating the ATM/NF-κB pathway.

Inhibition of nuclear factor kappa-B signaling reduces growth in medulloblastoma in vivo

Directory of Open Access Journals (Sweden)

Deckard Lindsey A

2011-04-01

Full Text Available Abstract Background Medulloblastoma is a highly malignant pediatric brain tumor that requires surgery, whole brain and spine irradiation, and intense chemotherapy for treatment. A more sophisticated understanding of the pathophysiology of medulloblastoma is needed to successfully reduce the intensity of treatment and improve outcomes. Nuclear factor kappa-B (NFκB is a signaling pathway that controls transcriptional activation of genes important for tight regulation of many cellular processes and is aberrantly expressed in many types of cancer. Methods To test the importance of NFκB to medulloblastoma cell growth, the effects of multiple drugs that inhibit NFκB, pyrrolidine dithiocarbamate, diethyldithiocarbamate, sulfasalazine, curcumin and bortezomib, were studied in medulloblastoma cell lines compared to a malignant glioma cell line and normal neurons. Expression of endogenous NFκB was investigated in cultured cells, xenograft flank tumors, and primary human tumor samples. A dominant negative construct for the endogenous inhibitor of NFκB, IκB, was prepared from medulloblastoma cell lines and flank tumors were established to allow specific pathway inhibition. Results We report high constitutive activity of the canonical NFκB pathway, as seen by Western analysis of the NFκB subunit p65, in medulloblastoma tumors compared to normal brain. The p65 subunit of NFκB is extremely highly expressed in xenograft tumors from human medulloblastoma cell lines; though, conversely, the same cells in culture have minimal expression without specific stimulation. We demonstrate that pharmacological inhibition of NFκB in cell lines halts proliferation and leads to apoptosis. We show by immunohistochemical stain that phosphorylated p65 is found in the majority of primary tumor cells examined. Finally, expression of a dominant negative form of the endogenous inhibitor of NFκB, dnIκB, resulted in poor xenograft tumor growth, with average tumor volumes

NIK and IKKbeta interdependence in NF-kappaB signalling--flux analysis of regulation through metabolites.

Science.gov (United States)

Kim, Hong-Bum; Evans, Iona; Smallwood, Rod; Holcombe, Mike; Qwarnstrom, Eva E

2010-02-01

Activation of the transcription factor NF-kappaB is central to control of immune and inflammatory responses. Cytokine induced activation through the classical or canonical pathway relies on degradation of the inhibitor, IkappaBalpha and regulation by the IKKbeta kinase. In addition, the NF-kappaB is activated through the NF-kappaB-inducing kinase, NIK. Analysis of the IKK/NIK inter-relationship and its impact on NF-kappaB control, were analysed by mathematical modelling, using matrix formalism and stoichiometrically balanced reactions. The analysis considered a range of bio-reactions and core metabolites and their role in relation to kinase activation and in control of specific steps of the NF-kappaB pathway. The model predicts a growth-rate and time-dependent transfer of the primary kinase activity from IKKbeta to NIK. In addition, it suggests that NIK/IKKbeta interdependence is controlled by intermediates of phosphoribosylpyrophosphate (PRPP) within the glycolysis pathway, and thus, identifies a link between specific metabolic events and kinase activation in inflammatory signal transduction. Subsequent in vitro experiments, carried out to validate the impact of IKK/NIK interdependence, confirmed signal amplification at the level of the NF-kappaB/IkappaBalpha complex control in the presence of both kinases. Further, they demonstrate that the induced potentiation is due to synergistic enhancement of relA-dependent activation. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

TLR4 activates NF-κB in human ovarian granulosa tumor cells

International Nuclear Information System (INIS)

Woods, Dori C.; White, Yvonne A.R.; Dau, Caroline; Johnson, A.L.

2011-01-01

Highlights: → TLR4 is expressed in human ovarian granulosa tumor cells. → Acting through TLR4, LPS and HSP60 induce a NFκB signaling cascade in human ovarian granulosa tumor cells. → NFκB activation or inhibition did not alter chemosensitivity to TRAIL or cisplatin. -- Abstract: Previous studies have demonstrated expression of Toll-like receptors (TLRs) in the surface epithelium of normal ovaries (OSE) and in epithelial ovarian tumors. Most notably, OSE-derived cancers express TLR4, which activates the nuclear factor-kappa B (NF-κB) signaling cascade as a mediator of inflammatory response. Currently, there is considerable interest in elucidating the role of TLR-mediated signaling in cancers. Nevertheless, the expression of TLRs in granulosa cell tumors (GCTs) of the ovary, and the extent to which GCT expression of TLRs may influence cell-signaling pathways and/or modulate the efficacy of chemotherapeutics, has yet to be determined. In the present study, human GCT lines (COV434 and KGN) were utilized to evaluate expression of functional TLR4. TLR4 is expressed in GCT cell lines and ligation of TLR4 with bacterial lipopolysaccharide (LPS) led to IκB degradation and activation of NF-κB. NF-κB activation was confirmed by nuclear localization of NF-κB p65 following treatment with LPS and the naturally occurring ligand, HSP60. Notably, immunoneutralization of TLR4 blocked nuclear localization, and inhibition of NF-κB signaling attenuated LPS-induced TNFα plus increased doubling time in both cell lines. Contradictory to reports using human OSE cell lines, inhibition of NF-κB signaling failed to sensitize GCT lines to TRAIL or cisplatin. In summary, findings herein are the first to demonstrate a functional TLR-signaling pathway specifically in GCTs, and indicate that in contrast to OSE-derived cancers, inhibition of NF-κB does not sensitize GCTs to TRAIL or cisplatin.

PDK1 in NF-κB signaling is a target of Xanthium strumarium methanolic extract-mediated anti-inflammatory activities.

Science.gov (United States)

Hossen, Muhammad Jahangir; Cho, Jae Youl; Kim, Daewon

2016-08-22

Xanthium strumarium L. (Asteraceae) has traditionally been used to treat bacterial infections, nasal sinusitis, urticaria, arthritis, chronic bronchitis and rhinitis, allergic rhinitis, edema, lumbago, and other ailments. However, the molecular mechanisms by which this plant exerts its anti-inflammatory effects are poorly characterized. Here we studied the immunopharmacological activities of the methanolic extract of the aerial parts of this plant (Xs-ME) and validated its pharmacological targets. To evaluate the anti-inflammatory activity of Xs-ME, we employed lipopolysaccharide (LPS)-treated macrophages and an HCl/EtOH-induced mouse model of gastritis. We also used HPLC to identify the potentially active anti-inflammatory components of this extract. The molecular mechanisms of its anti-inflammatory activity were studied by kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) were both suppressed by Xs-ME. Moreover, orally administered Xs-ME ameliorated HCl/EtOH-induced gastric lesions. Furthermore, this extract downregulated the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 and reduced the nuclear levels of NF-κB. Signaling events upstream of NF-κB translocation, such as phosphorylation of AKT and the formation of PDK1-AKT signaling complexes, were also inhibited by Xs-ME. Moreover, Xs-ME suppressed the enzymatic activity of PDK1. Additionally, PDK1-induced luciferase activity and Akt phosphorylation were both inhibited by Xs-ME. We also identified the polyphenol resveratrol as a likely active anti-inflammatory component in Xs-ME that targets PDK1. Xs-ME exerts anti-inflammatory activity in vitro and in vivo by inhibiting PDK1 kinase activity and blocking signaling to its downstream transcription factor, NF-κB. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cardiac-specific overexpression of catalase prevents diabetes-induced pathological changes by inhibiting NF-κB signaling activation in the heart.

Science.gov (United States)

Cong, Weitao; Ruan, Dandan; Xuan, Yuanhu; Niu, Chao; Tao, Youli; Wang, Yang; Zhan, Kungao; Cai, Lu; Jin, Litai; Tan, Yi

2015-12-01

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Oleamide suppresses lipopolysaccharide-induced expression of iNOS and COX-2 through inhibition of NF-kappaB activation in BV2 murine microglial cells.

Science.gov (United States)

Oh, Young Taek; Lee, Jung Yeon; Lee, Jinhwa; Lee, Ju Hie; Kim, Ja-Eun; Ha, Joohun; Kang, Insug

2010-05-03

Oleamide (cis-9-octadecenamide) is an endogenous sleep-inducing fatty acid amide that accumulates in the cerebrospinal fluid of the sleep-deprived animals. Microglia are the major immune cells involved in neuroinflammation causing brain damage during infection, ischemia, and neurodegenerative disease. In this study, we examined the effects of oleamide on LPS-induced production of proinflammatory mediators and the mechanisms involved in BV2 microglia. Oleamide inhibited LPS-induced production of NO and prostaglandin E2 as well as expression of iNOS and COX-2. We showed that oleamide blocked LPS-induced NF-kappaB activation and phosphorylation of inhibitor kappaB kinase (IKK). We also showed that oleamide inhibited LPS-induced phosphorylation of Akt, p38 MAPK, and ERK, activation of PI 3-kinase, and accumulation of reactive oxygen species (ROS). Finally, we showed that a specific antagonist of the CB2 receptor, AM630, blocked the inhibitory effects of oleamide on LPS-induced production of proinflammatory mediators and activation of NF-kappaB. Taken together, our results suggest that oleamide shows an anti-inflammatory effect through inhibition of NF-kappaB activation in LPS-stimulated BV2 microglia. 2010 Elsevier Ireland Ltd. All rights reserved.

NF-κB signaling is activated and confers resistance to apoptosis in three-dimensionally cultured EGFR-mutant lung adenocarcinoma cells

International Nuclear Information System (INIS)

Sakuma, Yuji; Yamazaki, Yukiko; Nakamura, Yoshiyasu; Yoshihara, Mitsuyo; Matsukuma, Shoichi; Koizume, Shiro; Miyagi, Yohei

2012-01-01

Highlights: ► EGFR-mutant cells in 3D culture resist EGFR inhibition compared with suspended cells. ► Degradation of IκB and activation of NF-κB are observed in 3D-cultured cells. ► Inhibiting NF-κB enhances the efficacy of the EGFR inhibitor in 3D-cultured cells. -- Abstract: Epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells in suspension undergo apoptosis to a greater extent than adherent cells in a monolayer when EGFR autophosphorylation is inhibited by EGFR tyrosine kinase inhibitors (TKIs). This suggests that cell adhesion to a culture dish may activate an anti-apoptotic signaling pathway other than the EGFR pathway. Since the microenvironment of cells cultured in a monolayer are substantially different to that of cells existing in three-dimension (3D) in vivo, we assessed whether two EGFR-mutant lung adenocarcinoma cell lines, HCC827 and H1975, were more resistant to EGFR TKI-induced apoptosis when cultured in a 3D extracellular matrix (ECM) as compared with in suspension. The ECM-adherent EGFR-mutant cells in 3D were significantly less sensitive to treatment with WZ4002, an EGFR TKI, than the suspended cells. Further, a marked degradation of IκBα, the inhibitor of nuclear factor (NF)-κB, was observed only in the 3D-cultured cells, leading to an increase in the activation of NF-κB. Moreover, the inhibition of NF-κB with pharmacological inhibitors enhanced EGFR TKI-induced apoptosis in 3D-cultured EGFR-mutant cells. These results suggest that inhibition of NF-κB signaling would render ECM-adherent EGFR-mutant lung adenocarcinoma cells in vivo more susceptible to EGFR TKI-induced cell death.

Identification of a novel A20-binding inhibitor of nuclear factor-kappa B activation termed ABIN-2.

Science.gov (United States)

Van Huffel, S; Delaei, F; Heyninck, K; De Valck, D; Beyaert, R

2001-08-10

The nuclear factor kappaB (NF-kappaB) plays a central role in the regulation of genes implicated in immune responses, inflammatory processes, and apoptotic cell death. The zinc finger protein A20 is a cellular inhibitor of NF-kappaB activation by various stimuli and plays a critical role in terminating NF-kappaB responses. The underlying mechanism for NF-kappaB inhibition by A20 is still unknown. A20 has been shown to interact with several proteins including tumor necrosis factor (TNF) receptor-associated factors 2 and 6, as well as the inhibitory protein of kappaB kinase (IKK) gamma protein. Here we report the cloning and characterization of ABIN-2, a previously unknown protein that binds to the COOH-terminal zinc finger domain of A20. NF-kappaB activation induced by TNF and interleukin-1 is inhibited by overexpression of ABIN-2. The latter also inhibits NF-kappaB activation induced by overexpression of receptor-interacting protein or TNF receptor-associated factor 2. In contrast, NF-kappaB activation by overexpression of IKKbeta or direct activators of the IKK complex, such as Tax, cannot be inhibited by ABIN-2. These results indicate that ABIN-2 interferes with NF-kappaB activation upstream of the IKK complex and that it might contribute to the NF-kappaB-inhibitory function of A20.

p38 mitogen-activated protein kinase up-regulates NF-κB transcriptional activation through RelA phosphorylation during stretch-induced myogenesis

International Nuclear Information System (INIS)

Ji, Guoping; Liu, Dongxu; Liu, Jing; Gao, Hui; Yuan, Xiao; Shen, Gang

2010-01-01

p38 MAPK and nuclear factor-B (NF-B) signaling pathways play an indispensable role in the control of skeletal myogenesis. The specific contribution of these signaling pathways to the response of myoblast to the mechanical stimulation and the molecular mechanisms underlying this response remain unresolved. Using an established in vitro model, we now show that p38 MAP kinase activity regulates the transcriptional activation of NF-κB in response to mechanical stimulation of myoblasts. Furthermore, SB203580 blocked stretch-induced NF-κB activation during myogenesis, not through down-regulation of degradation of IκB-α, and consequent translocation of the p65 subunit of NF-κB to the nucleus. It is likely that stretch-induced NF-κB activation by phosphorylation of p65 NF-κB. Moreover, depletion of p38α using siRNA significantly reduces stretch-induced phosphorylation of RelA and NF-κB activity. These results provides the first evidence of a cross-talk between p38 MAPK and NF-κB signaling pathways during stretch-induced myogenesis, with phosphorylation of RelA being one of the effectors of this promyogenic mechanism. The α isoform of p38MAP kinase regulates the transcriptional activation of NF-κB following stimulation with cyclic stretch.

p38 mitogen-activated protein kinase up-regulates NF-{kappa}B transcriptional activation through RelA phosphorylation during stretch-induced myogenesis

Energy Technology Data Exchange (ETDEWEB)

Ji, Guoping [Department of Orthodontics, College of Stomatology, Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Research Institute of Stomatology, Shanghai 200011 (China); Liu, Dongxu [Department of Orthodontics, College of Stomatology, Shandong University, Jinan, Shandong Province 250012 (China); Liu, Jing [Department of Orthodontics, The Affiliated Qingdao Municipal Hospital, Qingdao University, Qingdao, Shandong Province 266075 (China); Gao, Hui [Department of Orthodontics, Tianjin Stomatological Hospital, Tianjin 300041 (China); Yuan, Xiao, E-mail: yuanxiaoqd@163.com [Department of Orthodontics, The Affiliated Qingdao Municipal Hospital, Qingdao University, Qingdao, Shandong Province 266075 (China); Shen, Gang, E-mail: ganshen2007@163.com [Department of Orthodontics, College of Stomatology, Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Research Institute of Stomatology, Shanghai 200011 (China)

2010-01-01

p38 MAPK and nuclear factor-B (NF-B) signaling pathways play an indispensable role in the control of skeletal myogenesis. The specific contribution of these signaling pathways to the response of myoblast to the mechanical stimulation and the molecular mechanisms underlying this response remain unresolved. Using an established in vitro model, we now show that p38 MAP kinase activity regulates the transcriptional activation of NF-{kappa}B in response to mechanical stimulation of myoblasts. Furthermore, SB203580 blocked stretch-induced NF-{kappa}B activation during myogenesis, not through down-regulation of degradation of I{kappa}B-{alpha}, and consequent translocation of the p65 subunit of NF-{kappa}B to the nucleus. It is likely that stretch-induced NF-{kappa}B activation by phosphorylation of p65 NF-{kappa}B. Moreover, depletion of p38{alpha} using siRNA significantly reduces stretch-induced phosphorylation of RelA and NF-{kappa}B activity. These results provides the first evidence of a cross-talk between p38 MAPK and NF-{kappa}B signaling pathways during stretch-induced myogenesis, with phosphorylation of RelA being one of the effectors of this promyogenic mechanism. The {alpha} isoform of p38MAP kinase regulates the transcriptional activation of NF-{kappa}B following stimulation with cyclic stretch.

TLR2 ligands induce NF-κB activation from endosomal compartments of human monocytes.

Directory of Open Access Journals (Sweden)

Karim J Brandt

Full Text Available Localization of Toll-like receptors (TLR in subcellular organelles is a major strategy to regulate innate immune responses. While TLR4, a cell-surface receptor, signals from both the plasma membrane and endosomal compartments, less is known about the functional role of endosomal trafficking upon TLR2 signaling. Here we show that the bacterial TLR2 ligands Pam3CSK4 and LTA activate NF-κB-dependent signaling from endosomal compartments in human monocytes and in a NF-κB sensitive reporter cell line, despite the expression of TLR2 at the cell surface. Further analyses indicate that TLR2-induced NF-κB activation is controlled by a clathrin/dynamin-dependent endocytosis mechanism, in which CD14 serves as an important upstream regulator. These findings establish that internalization of cell-surface TLR2 into endosomal compartments is required for NF-κB activation. These observations further demonstrate the need of endocytosis in the activation and regulation of TLR2-dependent signaling pathways.

Canonical and Non-Canonical NF-κB Signaling Promotes Breast Cancer Tumor-Initiating Cells

Science.gov (United States)

Kendellen, Megan F.; Bradford, Jennifer W.; Lawrence, Cortney L.; Clark, Kelly S.; Baldwin, Albert S.

2014-01-01

Tumor-initiating cells (TICs) are a sub-population of cells that exhibit a robust ability to self-renew and contribute to the formation of primary tumors, the relapse of previously treated tumors, and the development of metastases. TICs have been identified in various tumors, including those of the breast, and are particularly enriched in the basal-like and claudin-low subtypes of breast cancer. The signaling pathways that contribute to the function and maintenance of TICs are under intense study. We explored the potential involvement of the NF-κB family of transcription factors in TICs in cell lines that are representative of basal-like and claudin-low breast cancer. NF-κB was found to be activated in breast cancer cells that form tumorspheres efficiently. Moreover, both canonical and non-canonical NF-κB signaling is required for these cells to self-renew in vitro and to form xenograft tumors efficiently in vivo using limiting dilutions of cells. Consistent with this, canonical and non-canonical NF-κB signaling is activated in TICs isolated from breast cancer cell lines. Experimental results indicate that NF-κB promotes the function of TICs by stimulating epithelial-to-mesenchymal transition (EMT) and by upregulating the expression of the inflammatory cytokines IL-1β and IL-6. The results suggest the use of NF-κB inhibitors for clinical therapy of certain breast cancers. PMID:23474754

High glucose induces activation of NF-κB inflammatory signaling through IκBα sumoylation in rat mesangial cells

International Nuclear Information System (INIS)

Huang, Wei; Xu, Ling; Zhou, Xueqin; Gao, Chenlin; Yang, Maojun; Chen, Guo; Zhu, Jianhua; Jiang, Lan; Gan, Huakui; Gou, Fang; Feng, Hong; Peng, Juan; Xu, Yong

2013-01-01

Highlights: •The expression of SUMO1, SUMO2/3 under high glucose was obviously enhanced. •High glucose induced degradation of IκBα and activation of NF-κB pathway. •Sumoylation of IκBα in high glucose were significantly decreased. •The proteasome inhibitor MG132 could partially revert the degradation of IκBα. -- Abstract: The posttranslational modification of proteins by small ubiquitin-like modifiers (SUMOs) has emerged as an important regulatory mechanism for the alteration of protein activity, stability, and cellular localization. The latest research demonstrates that sumoylation is extensively involved in the regulation of the nuclear factor κB (NF-κB) pathway, which plays a critical role in the regulation of inflammation and contributes to fibrosis in diabetic nephropathy (DN). However, the role of sumoylation in the regulation of NF-κB signaling in DN is still unclear. In the present study, we cultured rat glomerular mesangial cells (GMCs) stimulated by high glucose and divided GMCs into six groups: normal glucose group (5.6 mmol/L), high glucose groups (10, 20, and 30 mmol/L), mannitol group (i.e., osmotic control group), and MG132 intervention group (30 mmol/L glucose with MG132, a proteasome inhibitor). The expression of SUMO1, SUMO2/3, IκBα, NF-κBp65, and monocyte chemotactic protein 1 (MCP-1) was measured by Western blot, reverse-transcription polymerase chain reaction, and indirect immunofluorescence laser scanning confocal microscopy. The interaction between SUMO1, SUMO2/3, and IκBα was observed by co-immunoprecipitation. The results showed that the expression of SUMO1 and SUMO2/3 was dose- and time-dependently enhanced by high glucose (p < 0.05). However, the expression of IκBα sumoylation in high glucose was significantly decreased compared with the normal glucose group (p < 0.05). The expression of IκBα was dose- and time-dependently decreased, and NF-κBp65 and MCP-1 were increased under high glucose conditions, which

Vitamin K2 stimulates osteoblastogenesis and suppresses osteoclastogenesis by suppressing NF-κB activation.

Science.gov (United States)

Yamaguchi, Masayoshi; Weitzmann, M Neale

2011-01-01

Several bone protective factors are reported to exhibit stimulatory activities on bone formation coupled with inhibitory effects on bone resorption; one such factor is vitamin K2. Vitamin K species [K1 (phylloquinone) and K2 (menaquinone)] have long been associated with bone protective activities and are receiving intense interest as nutritional supplements for the prevention or amelioration of bone disease in humans. However, the mechanisms of vitamin K action on the skeleton are poorly defined. Activation of the nuclear factor κB (NF-κB) signal transduction pathway is essential for osteoclast formation and resorption. By contrast, NF-κB signaling potently antagonizes osteoblast differentiation and function, prompting us to speculate that NF-κB antagonists may represent a novel class of dual anti-catabolic and pro-anabolic agents. We now show that vitamin K2 action on osteoblast and osteoclast formation and activity is accomplished by down-regulating basal and cytokine-induced NF-κB activation, by increasing IκB mRNA, in a γ-carboxylation-independent manner. Furthermore, vitamin K2 prevented repression by tumor necrosis factor α (TNFα) of SMAD signaling induced by either transforming growth factor ß (TGFß) or bone morphogenetic protein-2 (BMP-2). Vitamin K2 further antagonized receptor activator of NF-κB (RANK) ligand (RANKL)-induced NF-κB activation in osteoclast precursors. Our data provide a novel mechanism to explain the dual pro-anabolic and anti-catabolic activities of vitamin K2, and may further support the concept that pharmacological modulation of NF-κB signal transduction may constitute an effective mechanism for ameliorating pathological bone loss and for promoting bone health.

High-Mobility Group Box 1 Mediates Fibroblast Activity via RAGE-MAPK and NF-κB Signaling in Keloid Scar Formation

Directory of Open Access Journals (Sweden)

Jihee Kim

2017-12-01

Full Text Available Emerging studies have revealed the involvement of high-mobility group box 1 (HMGB1 in systemic fibrotic diseases, yet its role in the cutaneous scarring process has not yet been investigated. We hypothesized that HMGB1 may promote fibroblast activity to cause abnormal cutaneous scarring. In vitro wound healing assay with normal and keloid fibroblasts demonstrated that HMGB1 administration promoted the migration of both fibroblasts with increased speed and a greater traveling distance. Treatment of the HMGB1 inhibitor glycyrrhizic acid (GA showed an opposing effect on both activities. To analyze the downstream mechanism, the protein levels of extracellular signal-regulated kinase (ERK 1/2, protein kinase B (AKT, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB were measured by western blot analysis. HMGB1 increased the expression levels of ERK1/2, AKT, and NF-κB compared to the control, which was suppressed by GA. HMGB1 promoted both normal and keloid fibroblasts migration to a degree equivalent to that achieved with TGF-β. We concluded that HMGB1 activates fibroblasts via the receptor for advanced glycation end product (RAGE—mitogen-activated protein kinases (MAPK and NF-κB interaction signaling pathways. Further knowledge of the relationship of HMGB1 with skin fibrosis may lead to a promising clinical approach to manage abnormal scarring.

High-Mobility Group Box 1 Mediates Fibroblast Activity via RAGE-MAPK and NF-κB Signaling in Keloid Scar Formation.

Science.gov (United States)

Kim, Jihee; Park, Jong-Chul; Lee, Mi Hee; Yang, Chae Eun; Lee, Ju Hee; Lee, Won Jai

2017-12-28

Emerging studies have revealed the involvement of high-mobility group box 1 (HMGB1) in systemic fibrotic diseases, yet its role in the cutaneous scarring process has not yet been investigated. We hypothesized that HMGB1 may promote fibroblast activity to cause abnormal cutaneous scarring. In vitro wound healing assay with normal and keloid fibroblasts demonstrated that HMGB1 administration promoted the migration of both fibroblasts with increased speed and a greater traveling distance. Treatment of the HMGB1 inhibitor glycyrrhizic acid (GA) showed an opposing effect on both activities. To analyze the downstream mechanism, the protein levels of extracellular signal-regulated kinase (ERK) 1/2, protein kinase B (AKT), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were measured by western blot analysis. HMGB1 increased the expression levels of ERK1/2, AKT, and NF-κB compared to the control, which was suppressed by GA. HMGB1 promoted both normal and keloid fibroblasts migration to a degree equivalent to that achieved with TGF-β. We concluded that HMGB1 activates fibroblasts via the receptor for advanced glycation end product (RAGE)-mitogen-activated protein kinases (MAPK) and NF-κB interaction signaling pathways. Further knowledge of the relationship of HMGB1 with skin fibrosis may lead to a promising clinical approach to manage abnormal scarring.

The truncate mutation of Notch2 enhances cell proliferation through activating the NF-κB signal pathway in the diffuse large B-cell lymphomas.

Directory of Open Access Journals (Sweden)

Xinxia Zhang

Full Text Available The Notch2 is a critical membrane receptor for B-cell functions, and also displays various biological roles in lymphoma pathogenesis. In this article, we reported that 3 of 69 (4.3% diffuse large B-cell lymphomas (DLBCLs exhibited a truncate NOTCH2 mutation at the nucleotide 7605 (G/A in the cDNA sequence, which led to partial deletion of the C-terminal of PEST (proline-, glutamic acid-, serine- and threonine-rich domain. The truncate Notch2 activated both the Notch2 and the NF-κB signals and promoted the proliferation of B-cell lymphoma cell lines, including DLBCL and Burkitt's lymphoma cell lines. Moreover, the ectopic proliferation was completely inhibited by ammonium pyrrolidinedithiocarbamate (PDTC, an NF-κB inhibitor. Simultaneously, PDTC also reduced the expression level of Notch2. Based on these results, we conclude that the Notch2 receptor with PEST domain truncation enhances cell proliferation which may be associated with the activation of the Notch2 and the NF-κB signaling. Our results are expected to provide a possible target for new DLBCL therapies by suppressing the Notch2 and the NF-κB signaling.

PSMB4 promotes multiple myeloma cell growth by activating NF-κB-miR-21 signaling

Energy Technology Data Exchange (ETDEWEB)

Zheng, Peihao; Guo, Honggang [Department of Hematology, Navy General Hospital, Beijing 100048 (China); Li, Guangchao [School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006 (China); Han, Siqi [Department of Medical Oncology, Jinling Hospital, Nanjing 210002 (China); Luo, Fei [Department of Stomatology, Jinling Hospital, Nanjing 210002 (China); Liu, Yi, E-mail: liuyi2033@163.com [Department of Hematology, Navy General Hospital, Beijing 100048 (China)

2015-03-06

Proteasomal subunit PSMB4, was recently identified as potential cancer driver genes in several tumors. However, the regulatory mechanism of PSMB4 on carcinogenesis process remains unclear. In this study, we investigated the expression and roles of PSMB4 in multiple myeloma (MM). We found a significant up-regulation of PSMB4 in MM plasma and cell lines. Ectopic overexpression of PSMB4 promoted cell growth and colony forming ability of MM cells, whereas inhibition of PSMB4 led to a decrease of such events. Furthermore, our results demonstrated the up-regulation of miR-21 and a positive correlation between the levels of miR-21 and PSMB4 in MM. Re-expression of miR-21 markedly rescued PSMB4 knockdown-mediated suppression of cell proliferation and clone-formation. Additionally, while enforced expression of PSMB4 profoundly increased NF-κB activity and the level of miR-21, PSMB4 knockdown or NF-κB inhibition suppressed miR-21 expression in MM cells. Taken together, our results demonstrated that PSMB4 regulated MM cell growth in part by activating NF-κB-miR-21 signaling, which may represent promising targets for novel specific therapies. - Highlights: • First reported upregulation of PSMB4 in MM plasma and cell lines. • PSMB4 promoted MM cell growth and colony forming ability. • Further found miR-21 was up-regulated by PSMB4 in MM plasma and cell lines. • PSMB4-induced miR-21 expression was modulated by NF-κB. • PSMB4-NF-κB-miR-21 axis may be potential therapeutic targets of MM.

HMBA Enhances Prostratin-Induced Activation of Latent HIV-1 via Suppressing the Expression of Negative Feedback Regulator A20/TNFAIP3 in NF-κB Signaling

Directory of Open Access Journals (Sweden)

Duchu Chen

2016-01-01

Full Text Available In the past decade, much emphasis has been put on the transcriptional activation of HIV-1, which is proposed as a promised strategy for eradicating latent HIV-1 provirus. Two drugs, prostratin and hexamethylene bisacetamide (HMBA, have shown potent effects as inducers for releasing HIV-1 latency when used alone or in combination, although their cellular target(s are currently not well understood, especially under drug combination. Here, we have shown that HMBA and prostratin synergistically release HIV-1 latency via different mechanisms. While prostratin strongly stimulates HMBA-induced HIV-1 transcription via improved P-TEFb activation, HMBA is capable of boosting NF-κB-dependent transcription initiation by suppressing prostratin-induced expression of the deubiquitinase A20, a negative feedback regulator in the NF-κB signaling pathway. In addition, HMBA was able to increase prostratin-induced phosphorylation and degradation of NF-κB inhibitor IκBα, thereby enhancing and prolonging prostratin-induced nuclear translocation of NF-κB, a prerequisite for stimulation of transcription initiation. Thus, by blocking the negative feedback circuit, HMBA functions as a signaling enhancer of the NF-κB signaling pathway.

Curcumin alleviates macrophage activation and lung inflammation induced by influenza virus infection through inhibiting the NF-κB signaling pathway.

Science.gov (United States)

Xu, Yiming; Liu, Ling

2017-09-01

Influenza A viruses (IAV) result in severe public health problems with worldwide each year. Overresponse of immune system to IAV infection leads to complications, and ultimately causing morbidity and mortality. Curcumin has been reported to have anti-inflammatory ability. However, its molecular mechanism in immune responses remains unclear. We detected the pro-inflammatory cytokine secretion and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB)-related protein expression in human macrophages or mice infected by IAV with or without curcumin treatment. We found that the IAV infection caused a dramatic enhancement of pro-inflammatory cytokine productions of human macrophages and mice immune cells. However, curcumin treatment after IAV infection downregulated these cytokines production in a dose-dependent manner. Moreover, the NF-κB has been activated in human macrophages after IAV infection, while administration of curcumin inhibited NF-κB signaling pathway via promoting the expression of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα), and inhibiting the translocation of p65 from cytoplasm to nucleus. In summary, IAV infection could result in the inflammatory responses of immune cells, especially macrophages. Curcumin has the therapeutic potentials to relieve these inflammatory responses through inhibiting the NF-κB signaling pathway. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Wogonin improves histological and functional outcomes, and reduces activation of TLR4/NF-κB signaling after experimental traumatic brain injury.

Directory of Open Access Journals (Sweden)

Chien-Cheng Chen

Full Text Available Traumatic brain injury (TBI initiates a neuroinflammatory cascade that contributes to neuronal damage and behavioral impairment. This study was undertaken to investigate the effects of wogonin, a flavonoid with potent anti-inflammatory properties, on functional and histological outcomes, brain edema, and toll-like receptor 4 (TLR4- and nuclear factor kappa B (NF-κB-related signaling pathways in mice following TBI.Mice subjected to controlled cortical impact injury were injected with wogonin (20, 40, or 50 mg·kg(-1 or vehicle 10 min after injury. Behavioral studies, histology analysis, and measurement of blood-brain barrier (BBB permeability and brain water content were carried out to assess the effects of wogonin. Levels of TLR4/NF-κB-related inflammatory mediators were also examined. Treatment with 40 mg·kg(-1 wogonin significantly improved functional recovery and reduced contusion volumes up to post-injury day 28. Wogonin also significantly reduced neuronal death, BBB permeability, and brain edema beginning at day 1. These changes were associated with a marked reduction in leukocyte infiltration, microglial activation, TLR4 expression, NF-κB translocation to nucleus and its DNA binding activity, matrix metalloproteinase-9 activity, and expression of inflammatory mediators, including interleukin-1β, interleukin-6, macrophage inflammatory protein-2, and cyclooxygenase-2.Our results show that post-injury wogonin treatment improved long-term functional and histological outcomes, reduced brain edema, and attenuated the TLR4/NF-κB-mediated inflammatory response in mouse TBI. The neuroprotective effects of wogonin may be related to modulation of the TLR4/NF-κB signaling pathway.

Polycystin-1 promotes PKCα-mediated NF-κB activation in kidney cells

International Nuclear Information System (INIS)

Banzi, Manuela; Aguiari, Gianluca; Trimi, Viky; Mangolini, Alessandra; Pinton, Paolo; Witzgall, Ralph; Rizzuto, Rosario; Senno, Laura del

2006-01-01

Polycystin-1 (PC1), the PKD1 gene product, is a membrane receptor which regulates many cell functions, including cell proliferation and apoptosis, both typically increased in cyst lining cells in autosomal dominant polycystic kidney disease. Here we show that PC1 upregulates the NF-κB signalling pathway in kidney cells to prevent cell death. Human embryonic kidney cell lines (HEK293 CTT ), stably expressing a PC1 cytoplasmic terminal tail (CTT), presented increased NF-κB nuclear levels and NF-κB-mediated luciferase promoter activity. This, consistently, was reduced in HEK293 cells in which the endogenous PC1 was depleted by RNA interference. CTT-dependent NF-κB promoter activation was mediated by PKCα because it was blocked by its specific inhibitor Ro-320432. Furthermore, it was observed that apoptosis, which was increased in PC1-depleted cells, was reduced in HEK293 CTT cells and in porcine kidney LtTA cells expressing a doxycycline-regulated CTT. Staurosporine, a PKC inhibitor, and parthenolide, a NF-κB inhibitor, significantly reduced the CTT-dependent antiapoptotic effect. These data reveal, therefore, a novel pathway by which polycystin-1 activates a PKCα-mediated NF-κB signalling and cell survival

Transforming growth factor-beta 1 (TGF-beta1) promotes IL-2 mRNA expression through the up-regulation of NF-kappaB, AP-1 and NF-AT in EL4 cells.

Science.gov (United States)

Han, S H; Yea, S S; Jeon, Y J; Yang, K H; Kaminski, N E

1998-12-01

Transforming growth factor beta1 (TGF-beta1) has been previously shown to modulate interleukin 2 (IL-2) secretion by activated T-cells. In the present studies, we determined that TGF-beta1 induced IL-2 mRNA expression in the murine T-cell line EL4, in the absence of other stimuli. IL-2 mRNA expression was significantly induced by TGF-beta1 (0.1-1 ng/ml) over a relatively narrow concentration range, which led to the induction of IL-2 secretion. Under identical condition, we examined the effect of TGF-beta1 on the activity of nuclear factor AT (NF-AT), nuclear factor kappaB (NF-kappaB), activator protein-1 (AP-1) and octamer, all of which contribute to the regulation of IL-2 gene expression. Electrophoretic mobility shift assays showed that TGF-beta1 markedly increased NF-AT, NF-kappaB and AP-1 binding to their respective cognate DNA binding sites, whereas octamer binding remained constant, as compared with untreated cells. Employing a reporter gene expression system with p(NF-kappaB)3-CAT, p(NF-AT)3-CAT and p(AP-1)3-CAT, TGF-beta1 treatment of transfected EL4 cells induced a dose-related increase in chloramphenicol acetyltransferase activity that correlated well with the DNA binding profile found in the electrophoretic mobility shift assay studies. These results show that TGF-beta1, in the absence of any additional stimuli, up-regulates the activity of key transcription factors involved in IL-2 gene expression, including NF-AT, NF-kappaB and AP-1, to help promote IL-2 mRNA expression by EL4 cells.

Herpes Simplex Virus 1 UL24 Abrogates the DNA Sensing Signal Pathway by Inhibiting NF-κB Activation.

Science.gov (United States)

Xu, Haiyan; Su, Chenhe; Pearson, Angela; Mody, Christopher H; Zheng, Chunfu

2017-04-01

Cyclic GMP-AMP synthase (cGAS) is a newly identified DNA sensor that recognizes foreign DNA, including the genome of herpes simplex virus 1 (HSV-1). Upon binding of viral DNA, cGAS produces cyclic GMP-AMP, which interacts with and activates stimulator of interferon genes (STING) to trigger the transcription of antiviral genes such as type I interferons (IFNs), and the production of inflammatory cytokines. HSV-1 UL24 is widely conserved among members of the herpesviruses family and is essential for efficient viral replication. In this study, we found that ectopically expressed UL24 could inhibit cGAS-STING-mediated promoter activation of IFN-β and interleukin-6 (IL-6), and UL24 also inhibited interferon-stimulatory DNA-mediated IFN-β and IL-6 production during HSV-1 infection. Furthermore, UL24 selectively blocked nuclear factor κB (NF-κB) but not IFN-regulatory factor 3 promoter activation. Coimmunoprecipitation analysis demonstrated that UL24 bound to the endogenous NF-κB subunits p65 and p50 in HSV-1-infected cells, and UL24 was also found to bind the Rel homology domains (RHDs) of these subunits. Furthermore, UL24 reduced the tumor necrosis factor alpha (TNF-α)-mediated nuclear translocation of p65 and p50. Finally, mutational analysis revealed that the region spanning amino acids (aa) 74 to 134 of UL24 [UL24(74-134)] is responsible for inhibiting cGAS-STING-mediated NF-κB promoter activity. For the first time, UL24 was shown to play an important role in immune evasion during HSV-1 infection. IMPORTANCE NF-κB is a critical component of the innate immune response and is strongly induced downstream of most pattern recognition receptors (PRRs), leading to the production of IFN-β as well as a number of inflammatory chemokines and interleukins. To establish persistent infection, viruses have evolved various mechanisms to counteract the host NF-κB pathway. In the present study, for the first time, HSV-1 UL24 was demonstrated to inhibit the activation of NF

Hepatitis C Virus NS3 Mediated Microglial Inflammation via TLR2/TLR6 MyD88/NF-κB Pathway and Toll Like Receptor Ligand Treatment Furnished Immune Tolerance.

Directory of Open Access Journals (Sweden)

Ayilam Ramachandran Rajalakshmy

Full Text Available Recent evidence suggests the neurotrophic potential of hepatitis C virus (HCV. HCV NS3 protein is one of the potent antigens of this virus mediating inflammatory response in different cell types. Microglia being the immune surveillance cells in the central nervous system (CNS, the inflammatory potential of NS3 on microglia was studied. Role of toll like receptor (TLR ligands Pam2CSK3 and Pam3CSK4 in controlling the NS3 mediated microglial inflammation was studied using microglial cell line CHME3.IL (Interleukin-8, IL-6, TNF-α (Tumor nicrosis factor alpha and IL-1β gene expressions were measured by semi quantitative RT-PCR (reverse transcription-PCR. ELISA was performed to detect IL-8, IL-6, TNF-α, IL-1β and IL-10 secretion. FACS (Flourescent activated cell sorting was performed to quantify TLR1, TLR2, TLR6, MyD88 (Myeloid differntiation factor 88, IkB-α (I kappaB alpha and pNF-κB (phosphorylated nuclear factor kappaB expression. Immunofluorescence staining was performed for MyD88, TLR6 and NF-κB (Nuclear factor kappaB. Student's t-test or One way analysis of variance with Bonferoni post hoc test was performed and p < 0.05 was considered significant.Microglia responded to NS3 by secreting IL-8, IL-6, TNF-α and IL-1β via TLR2 or TLR6 mediated MyD88/NF-κB pathway. Transcription factor NF-κB was involved in activating the cytokine gene expression and the resultant inflammatory response was controlled by NF-κB inhibitor, Ro106-9920, which is known to down regulate pro-inflammatory cytokine secretion. Activation of the microglia by TLR agonists Pam3CSK4 and Pam2CSK4 induced immune tolerance against NS3. TLR ligand treatment significantly down regulated pro-inflammatory cytokine secretion in the microglia. IL-10 secretion was suggested as the possible mechanism by which TLR agonists induced immune tolerance. NS3 as such was not capable of self-inducing immune tolerance in microglia.In conclusion, NS3 protein was capable of activating

Andrographolide inhibits multiple myeloma cells by inhibiting the TLR4/NF-κB signaling pathway.

Science.gov (United States)

Gao, Hui; Wang, Jianrong

2016-02-01

Andrographolide is an active component from the extract of Andrographis paniculata [(Burm.f) Nees], a medicinal plant from the Acanthaceae family. Pharmacological studies have revealed that andrographolide possesses anti-bacterial, anti-inflammatory, anti-viral, immune regulatory and hepatoprotective properties, and is efficacious in the treatment of cardiovascular diseases, while exhibiting low toxicity and low cost. The present study aimed to determine the inhibitory effects of andrographolide on the growth of multiple myeloma (MM) cells and its possible impact on the Toll-like receptor (TLR)4/nuclear factor (NF)-κB signaling pathway. Cell proliferation was detected using an MTT assay, cellular apoptosis was measured using flow cytometry, and caspase-9/3 activation were assessed using colorimetric assay kits. Furthermore, TLR4 and NF-κB protein expression was determined by western blot analysis. The results revealed that andrographolide reduced the proliferation, while increasing cellular apoptosis and caspase-9/3 activation of MM cells, in addition to downregulating the expression of TLR4 and NF-κB protein. Of note, TLR4- or NF-κB-targeting small-interfering (si)RNA enhanced the andrographolide-induced inhibition of cell proliferation and induction of apoptosis of MM cells. The results of the present study therefore suggested that andrographolide inhibited multiple myeloma cells via the TLR4/NF-κB signaling pathway.

Downregulation of miR-199b promotes the acute spinal cord injury through IKKβ-NF-κB signaling pathway activating microglial cells

Energy Technology Data Exchange (ETDEWEB)

Zhou, Heng-Jun [Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang (China); Wang, Li-Qing [Department of Anesthesia, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003 (China); Xu, Qing-Sheng; Fan, Zuo-Xu; Zhu, Yu; Jiang, Hao; Zheng, Xiu-Jue; Ma, Yue-Hui [Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang (China); Zhan, Ren-Ya, E-mail: zhanry148@163.com [Department of Neurosurgery, the First Affiliated Hospital, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, Zhejiang (China)

2016-11-15

Inflammatory response played an important role in the progression of spinal cord injury (SCI). Several miRNAs were associated with the pathology of SCI. However, the molecular mechanism of miRNA involving in inflammatory response in acute SCI (ASCI) was poorly understood. Sprague-Dawley (SD) rats were divided into 2 groups: control group (n=6) and acute SCI (ASCI) group (n=6). The expression of miR-199b and IκB kinase β-nuclear factor-kappa B (IKKβ-NF-κB) signaling pathway were evaluated by quantitative reverse transcription-PCR (qRT-PCR) in rats with ASCI and in primary microglia activated by lipopolysaccharide (LPS). We found that downregulation of miR-199b and activation of IKKβ/NF-κB were observed in rats after ASCI and in activated microglia. miR-199b negatively regulated IKKβ by targeting its 3′- untranslated regions (UTR) through using luciferase reporter assay. Overexpression of miR-199b reversed the up-regulation of IKKβ, p-p65, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in LPS-treated BV2 cells assessed by western blotting analysis. In addition, BMS-345541 reversed the up-regulation effects of miR-199b inhibitor on the expression of TNF-α and IL-1β. In the SCI rats, overexpression of miR-199b attenuated ASCI and decreased the expression of IKKβ-NF-κB signaling pathway and TNF-α and IL-1β. These results indicated that miR-199b attenuated ASCI at least partly through IKKβ-NF-κB signaling pathway and affecting the function of microglia. Our findings suggest that miR-199b may be employed as therapeutic for spinal cord injury. - Highlights: • Downregulation of miR-199b and activation of IKKβ/NF-κB were observed in rat after SCI. • miR-199b negatively regulated IKKβ by targeting its 3′-UTR. • miR-199b overexpression reversed the increasing IKKβ, p-p65, TNF-α and IL-1β in LPS-treated BV2. • BMS-345541 reversed the up-regulation of TNF-α and IL-1β induced by miR-199b inhibitor. • Overexpression of miR-199b

[6]-Gingerol Prevents Disassembly of Cell Junctions and Activities of MMPs in Invasive Human Pancreas Cancer Cells through ERK/NF-κB/Snail Signal Transduction Pathway

Directory of Open Access Journals (Sweden)

Sung Ok Kim

2013-01-01

Full Text Available To study the effects of [6]-gingerol, a ginger phytochemical, on tight junction (TJ molecules, we investigated TJ tightening and signal transduction pathways in human pancreatic duct cell-derived cancer cell line PANC-1. The following methods were utilized: MTT assay to determine cytotoxicity; zymography to examine matrix metalloproteinase (MMP activities; transepithelial electrical resistance (TER and paracellular flux for TJ measurement; RT-PCR and immunoblotting for proteins related to TJ and invasion; and EMSA for NF-κB activity in PANC-1 cells. Results revealed that TER significantly increased and claudin 4 and MMP-9 decreased compared to those of the control. TJ protein levels, including zonula occludens (ZO- 1, occludin, and E-cadherin, increased in [6]-gingerol-treated cells, which correlated with a decrease in paracellular flux and MMP activity. Furthermore, NF-κB/Snail nuclear translocation was suppressed via downregulation of the extracellular signal-regulated kinase (ERK pathway in response to [6]-gingerol treatment. Moreover, treatment with U0126, an ERK inhibitor, completely blocked NF-κB activity. In conclusion, these findings demonstrate that [6]-gingerol regulates TJ-related proteins and suppresses invasion and metastasis through NF-κB/Snail inhibition via inhibition of the ERK pathway. Therefore, [6]-gingerol may suppress the invasive activity of PANC-1 cells.

Gastrin regulates ABCG2 to promote the migration, invasion and side populations in pancreatic cancer cells via activation of NF-κB signaling

Energy Technology Data Exchange (ETDEWEB)

Wang, Juan; Xin, Beibei; Wang, Hui; He, Xiaodan [School of Medicine, Nankai University, 94 Weijin Road, Tianjin 300071 (China); Wei, Wei; Zhang, Ti [Tianjin Medical University Cancer Institute and Hospital, Huanhu West Road, Tianjin 300060 (China); Shen, Xiaohong, E-mail: zebal2014@163.com [School of Medicine, Nankai University, 94 Weijin Road, Tianjin 300071 (China)

2016-08-01

Gastrin is absent in most normal adult pancreatic tissues but is highly expressed in pancreatic cancer tissues. Although Gastrin expression was reported to be associated with tumor proliferation in human pancreatic cancer, studies on the relationship between Gastrin and tumor metastasis in pancreatic cancer are rare. In this study, we performed an analysis to determine the effects of Gastrin on modulating the side populations, cell proportion and tumor cell metastatic potential and invasion activity and explored its mechanisms in pancreatic cancer. We indicated that Gastrin and ABCG2 were widely expressed in pancreatic cancer cell lines and overexpressed in cancer tissues. Gastrin induced ABCG2 expression, and this effect was mediated by NF-κB activation. Gastrin regulated the SP proportion of BxPC-3 cells via modulating ABCG2 expression. Through the regulation of the functions of NF-κB/ABCG2, Gastrin functionally promoted the migration and invasion in pancreatic cancer cell. The present study indicated that Gastrin induced ABCG2 expression by activating NF-κB and thereby modulated the SP proportion, tumor cell metastatic potential and invasion activity in pancreatic cancer. Gastrin could serve as an effective therapeutic target for the metastasis of pancreatic cancer. - Highlights: • Gastrin induces ABCG2 expression mediated by NF-κB activation. • Gastrin regulates NF-κB's function that binds to the ABCG2 promoter in BxPC-3 cells. • Gastrin promotes the SP proportion in BxPC-3 cells by modulating ABCG2 expression via activation of NF-κB molecule. • Gastrin induces an increase in migration and invasion potential in pancreatic cancer cell by regulating NF-κB/ABCG2 signaling.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Nie, Shaobo [Department of Orthopaedics, PLA General Hospital, Beijing 100853 (China); Xu, Jiawei [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhang, Chenghua [Department of Orthopaedics, Changle County Hospital of Traditional Chinese Medicine, Weifang 262400 (China); Xu, Chen [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Liu, Ming, E-mail: ming_li4717@sina.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yu, Degang, E-mail: ydg163@126.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China)

2016-01-29

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

International Nuclear Information System (INIS)

Nie, Shaobo; Xu, Jiawei; Zhang, Chenghua; Xu, Chen; Liu, Ming; Yu, Degang

2016-01-01

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Shigella dysenteriae infection activates proinflammatory response through β-catenin/NF-κB signaling pathway.

Directory of Open Access Journals (Sweden)

Ashidha Gopal

Full Text Available Shigella dysenteriae (S.dysenteriae the causative agent of bacillary dysentery invades the human colonic epithelium resulting in severe intestinal inflammatory response and epithelial destruction. However, the mechanism by which S.dysenteriae infection regulates proinflammatory cytokines during intestinal inflammation is still obscure. In this study, we evaluated whether the interaction of β-catenin and NF-κB regulates proinflammatory cytokines TNF-α and IL-8 by modulating GSK-3β activity during S.dysenteriae infection in rat ileal loop model. Here we demonstrated that S.dysenteriae infection stimulate β-catenin degradation which in turn decreased the association between NF-κB and β-catenin. Also, we showed that S.dysenteriae infection increased GSK-3β kinase activity which in turn phosphorylates β-catenin for its degradation by ubiquitination and upregulates IL-8 through NF-κB activation thereby leading to inflammation. Thus these findings revealed the role of β-catenin/ NF-κB and GSK-3β in modulating the inflammatory response during bacterial infection and also showed that β-catenin acts as a critical regulator of inflammation.

The Interplay between Cyclic AMP, MAPK, and NF-κB Pathways in Response to Proinflammatory Signals in Microglia

Directory of Open Access Journals (Sweden)

Mousumi Ghosh

2015-01-01

Full Text Available Cyclic AMP is an important intracellular regulator of microglial cell homeostasis and its negative perturbation through proinflammatory signaling results in microglial cell activation. Though cytokines, TNF-α and IL-1β, decrease intracellular cyclic AMP, the mechanism by which this occurs is poorly understood. The current study examined which signaling pathways are responsible for decreasing cyclic AMP in microglia following TNF-α stimulation and sought to identify the role cyclic AMP plays in regulating these pathways. In EOC2 microglia, TNF-α produced a dramatic reduction in cyclic AMP and increased cyclic AMP-dependent PDE activity that could be antagonized by Rolipram, myristoylated-PKI, PD98059, or JSH-23, implicating a role for PDE4, PKA, MEK, and NF-κB in this regulation. Following TNF-α there were significant increases in iNOS and COX-2 immunoreactivity, phosphorylated ERK1/2 and NF-κB-p65, IκB degradation, and NF-κB p65 nuclear translocation, which were reduced in the presence of high levels of cyclic AMP, indicating that reductions in cyclic AMP during cytokine stimulation are important for removing its inhibitory action on NF-κB activation and subsequent proinflammatory gene expression. Further elucidation of the signaling crosstalk involved in decreasing cyclic AMP in response to inflammatory signals may provide novel therapeutic targets for modulating microglial cell activation during neurological injury and disease.

p55PIK regulates alpha-fetoprotein expression through the NF-κB signaling pathway.

Science.gov (United States)

Ye, Guoguo; Sun, Ge; Cheng, Zhikui; Zhang, Lei; Hu, Kanghong; Xia, Xianmin; Zhou, Yin

2017-12-15

Alpha-fetoprotein (AFP) is regarded as a diagnostic and prognostic biomarker and a potential therapeutic target for hepatocellular carcinoma (HCC). However, the regulation of AFP expression in HCC remains poorly understood. This study aimed to investigate the mechanism by which AFP expression is regulated by p55PIK, an isoform of PI3K. Human HCC cell lines (HepG2 and Huh-7) were treated with p55PIK specific competitive inhibitor or shRNA, or p55PIK overexpression vector, in the absence or presence of NF-κB inhibitor PDTC. AFP expression was detected by quantitative real-time PCR and Western blotting. NF-κB responsive elements in AFP enhancer region were characterized by luciferase reporter assay. p55PIK significantly stimulated the expression of AFP by activating NF-κB signaling pathway in HCC cells. Furthermore, two NF-κB binding sites in AFP enhancer region were identified to be primarily responsible for p55PIK mediated upregulation of AFP expression. p55PIK/NF-κB signaling plays an important role in the upregulation of AFP expression in HCC. Copyright © 2017 Elsevier Inc. All rights reserved.

TGF-β1 activates the canonical NF-κB signaling to promote cell survival and proliferation in dystrophic muscle fibroblasts in vitro

Energy Technology Data Exchange (ETDEWEB)

Ma, Zhen-Yu [Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China); Department of Neurology, The Second Affiliated Hospital, Guangzhou Medical University, No.250 Changgang East Road, Guangzhou 510260, Guangdong Province (China); Zhong, Zhi-Gang; Qiu, Meng-Yao; Zhong, Yu-Hua [Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China); Zhang, Wei-Xi, E-mail: weixizhang@qq.com [Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China)

2016-03-18

Activated fibroblasts continue to proliferate at injury sites, leading to progressive muscular fibrosis in Duchenne muscular dystrophy (DMD). TGF-β1 is a dominant profibrotic mediator thought to play a critical role in muscle fibrosis; however, the implicated mechanisms are not fully understood. Here we showed that TGF-β1 increased the resistance to apoptosis and stimulated cell cycle progression in dystrophic muscle fibroblasts under serum deprivation conditions in vitro. TGF-β1 treatment activated the canonical NF-κB pathway; and we found that pharmacological inhibition of IKKβ with IMD-0354 and RelA gene knockdown with siRNA attenuated these effects of TGF-β1 on dystrophic muscle fibroblasts. Collectively, our data suggest that TGF-β1 prevents apoptosis and cell cycle arrest in dystrophic muscle fibroblasts through the canonical NF-κB signaling pathway. - Highlights: • TGF-β1 promotes survival and proliferation in dystrophic muscle fibroblasts. • TGF-β1 activated the canonical NF-κB pathway in dystrophic muscle fibroblasts. • Canonical NF-κB pathway mediates these effects of TGF-β1.

TGF-β1 activates the canonical NF-κB signaling to promote cell survival and proliferation in dystrophic muscle fibroblasts in vitro

International Nuclear Information System (INIS)

Ma, Zhen-Yu; Zhong, Zhi-Gang; Qiu, Meng-Yao; Zhong, Yu-Hua; Zhang, Wei-Xi

2016-01-01

Activated fibroblasts continue to proliferate at injury sites, leading to progressive muscular fibrosis in Duchenne muscular dystrophy (DMD). TGF-β1 is a dominant profibrotic mediator thought to play a critical role in muscle fibrosis; however, the implicated mechanisms are not fully understood. Here we showed that TGF-β1 increased the resistance to apoptosis and stimulated cell cycle progression in dystrophic muscle fibroblasts under serum deprivation conditions in vitro. TGF-β1 treatment activated the canonical NF-κB pathway; and we found that pharmacological inhibition of IKKβ with IMD-0354 and RelA gene knockdown with siRNA attenuated these effects of TGF-β1 on dystrophic muscle fibroblasts. Collectively, our data suggest that TGF-β1 prevents apoptosis and cell cycle arrest in dystrophic muscle fibroblasts through the canonical NF-κB signaling pathway. - Highlights: • TGF-β1 promotes survival and proliferation in dystrophic muscle fibroblasts. • TGF-β1 activated the canonical NF-κB pathway in dystrophic muscle fibroblasts. • Canonical NF-κB pathway mediates these effects of TGF-β1.

CC2D1A Regulates Human Intellectual and Social Function as well as NF-κB Signaling Homeostasis

Directory of Open Access Journals (Sweden)

M. Chiara Manzini

2014-08-01

Full Text Available Autism spectrum disorder (ASD and intellectual disability (ID are often comorbid, but the extent to which they share common genetic causes remains controversial. Here, we present two autosomal-recessive “founder” mutations in the CC2D1A gene causing fully penetrant cognitive phenotypes, including mild-to-severe ID, ASD, as well as seizures, suggesting shared developmental mechanisms. CC2D1A regulates multiple intracellular signaling pathways, and we found its strongest effect to be on the transcription factor nuclear factor κB (NF-κB. Cc2d1a gain and loss of function both increase activation of NF-κB, revealing a critical role of Cc2d1a in homeostatic control of intracellular signaling. Cc2d1a knockdown in neurons reduces dendritic complexity and increases NF-κB activity, and the effects of Cc2d1a depletion can be rescued by inhibiting NF-κB activity. Homeostatic regulation of neuronal signaling pathways provides a mechanism whereby common founder mutations could manifest diverse symptoms in different patients.

Purinergic signaling is required for fluid shear stress-induced NF-{kappa}B translocation in osteoblasts

Energy Technology Data Exchange (ETDEWEB)

Genetos, Damian C., E-mail: dgenetos@ucdavis.edu [Department of Anatomy, Cell Biology, and Physiology, School of Veterinary Medicine, University of California, Davis, CA (United States); Karin, Norman J. [Cell Biology and Biochemistry, Pacific Northwest National Laboratory, Richland, WA (United States); Geist, Derik J. [Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN (United States); Donahue, Henry J. [Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Pennsylvania State College of Medicine, Hershey, PA (United States); Duncan, Randall L. [Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN (United States)

2011-04-01

Fluid shear stress regulates gene expression in osteoblasts, in part by activation of the transcription factor NF-{kappa}B. We examined whether this process was under the control of purinoceptor activation. MC3T3-E1 osteoblasts under static conditions expressed the NF-{kappa}B inhibitory protein I{kappa}B{alpha} and exhibited cytosolic localization of NF-{kappa}B. Under fluid shear stress, I{kappa}B{alpha} levels decreased, and concomitant nuclear localization of NF-{kappa}B was observed. Cells exposed to fluid shear stress in ATP-depleted medium exhibited no significant reduction in I{kappa}B{alpha}, and NF-{kappa}B remained within the cytosol. Similar results were found using oxidized ATP or Brilliant Blue G, P2X{sub 7} receptor antagonists, indicating that the P2X{sub 7} receptor is responsible for fluid shear-stress-induced I{kappa}B{alpha} degradation and nuclear accumulation of NF-{kappa}B. Pharmacologic blockage of the P2Y6 receptor also prevented shear-induced I{kappa}B{alpha} degradation. These phenomena involved neither ERK1/2 signaling nor autocrine activation by P2X{sub 7}-generated lysophosphatidic acid. Our results suggest that fluid shear stress regulates NF-{kappa}B activity through the P2Y{sub 6} and P2X{sub 7} receptor.

Paeoniflorin Attenuates Inflammatory Pain by Inhibiting Microglial Activation and Akt-NF-κB Signaling in the Central Nervous System

Directory of Open Access Journals (Sweden)

Bo Hu

2018-05-01

Full Text Available Background/Aims: Paeoniflorin (PF is known to have anti-inflammatory and paregoric effects, but the mechanism underlying its analgesic effect remains unclear. The aim of this study was to clarify the effect of PF on Freund’s complete adjuvant (CFA-induced inflammatory pain and explore the underlying molecular mechanism. Methods: An inflammatory pain model was established by intraplantar injection of CFA in C57BL/6J mice. After intrathecal injection of PF daily for 8 consecutive days, thermal and mechanical withdrawal thresholds, the levels of inflammatory factors TNF-α, IL-1β and IL-6, microglial activity, and the expression of Akt-NF-κB signaling pathway in the spinal cord tissue were detected by animal ethological test, cell culture, enzyme-linked immunosorbent assay, immunofluorescence histochemistry, and western blot. Results: PF inhibited the spinal microglial activation in the CFA-induced pain model. The production of proinflammatory cytokines was decreased in the central nervous system after PF treatment both in vivo and in vitro. PF further displayed a remarkable effect on inhibiting the activation of Akt-NF-κB signaling pathway in vivo and in vitro. Conclusion: These results suggest that PF is a potential therapeutic agent for inflammatory pain and merits further investigation.

Mast cell chymase induces smooth muscle cell apoptosis by disrupting NF-κB-mediated survival signaling

International Nuclear Information System (INIS)

Leskinen, Markus J.; Heikkilae, Hanna M.; Speer, Mei Y.; Hakala, Jukka K.; Laine, Mika; Kovanen, Petri T.; Lindstedt, Ken A.

2006-01-01

Chymase released from activated mast cells induces apoptosis of vascular smooth muscle cells (SMCs) in vitro by degrading the pericellular matrix component fibronectin, so causing disruption of focal adhesion complexes and Akt dephosphorylation, which are necessary for cell adhesion and survival. However, the molecular mechanisms of chymase-mediated apoptosis downstream of Akt have remained elusive. Here, we show by means of RT-PCR, Western blotting, EMSA, immunocytochemistry and confocal microscopy, that chymase induces SMC apoptosis by disrupting NF-κB-mediated survival signaling. Following chymase treatment, the translocation of active NF-κB/p65 to the nucleus was partly abolished and the amount of nuclear p65 was reduced. Pretreatment of SMCs with chymase also inhibited LPS- and IL-1β-induced nuclear translocation of p65. The chymase-induced degradation of p65 was mediated by active caspases. Loss of NF-κB-mediated transactivation resulted in downregulation of bcl-2 mRNA and protein expression, leading to mitochondrial swelling and release of cytochrome c. The apoptotic process involved activation of both caspase 9 and caspase 8. The results reveal that, by disrupting the NF-κB-mediated survival-signaling pathway, activated chymase-secreting mast cells can mediate apoptosis of cultured arterial SMCs. Since activated mast cells colocalize with apoptotic SMCs in vulnerable areas of human atherosclerotic plaques, they may participate in the weakening and rupture of atherosclerotic plaques

XEDAR activates the non-canonical NF-κB pathway

International Nuclear Information System (INIS)

Verhelst, Kelly; Gardam, Sandra; Borghi, Alice; Kreike, Marja; Carpentier, Isabelle; Beyaert, Rudi

2015-01-01

Members of the tumor necrosis factor receptor (TNFR) superfamily are involved in a number of physiological and pathological responses by activating a wide variety of intracellular signaling pathways. The X-linked ectodermal dysplasia receptor (XEDAR; also known as EDA2R or TNFRSF27) is a member of the TNFR superfamily that is highly expressed in ectodermal derivatives during embryonic development and binds to ectodysplasin-A2 (EDA-A2), a member of the TNF family that is encoded by the anhidrotic ectodermal dysplasia (EDA) gene. Although XEDAR was first described in the year 2000, its function and molecular mechanism of action is still largely unclear. XEDAR has been reported to activate canonical nuclear factor κB (NF-κB) signaling and mitogen-activated protein (MAP) kinases. Here we report that XEDAR is also able to trigger the non-canonical NF-κB pathway, characterized by the processing of p100 (NF-κB2) into p52, followed by nuclear translocation of p52 and RelB. We provide evidence that XEDAR-induced p100 processing relies on the binding of XEDAR to TRAF3 and TRAF6, and requires the kinase activity of NIK and IKKα. We also show that XEDAR stimulation results in NIK accumulation and that p100 processing is negatively regulated by TRAF3, cIAP1 and A20. - Highlights: • XEDAR activates the non-canonical NF-κB pathway. • XEDAR-induced processing of p100 depends on XEDAR interaction with TRAF3 and TRAF6. • XEDAR-induced processing of p100 depends on NIK and IKKα activity. • Overexpression of XEDAR leads to NIK accumulation. • XEDAR-induced processing of p100 is negatively regulated by TRAF3 cIAP1 and A20

XEDAR activates the non-canonical NF-κB pathway

Energy Technology Data Exchange (ETDEWEB)

Verhelst, Kelly, E-mail: Kelly.Verhelst@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Gardam, Sandra, E-mail: s.gardam@garvan.org.au [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Borghi, Alice, E-mail: Alice.Borghi@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Kreike, Marja, E-mail: Marja.Kreike@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Carpentier, Isabelle, E-mail: Isabelle.Carpentier@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Beyaert, Rudi, E-mail: Rudi.Beyaert@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium)

2015-09-18

Members of the tumor necrosis factor receptor (TNFR) superfamily are involved in a number of physiological and pathological responses by activating a wide variety of intracellular signaling pathways. The X-linked ectodermal dysplasia receptor (XEDAR; also known as EDA2R or TNFRSF27) is a member of the TNFR superfamily that is highly expressed in ectodermal derivatives during embryonic development and binds to ectodysplasin-A2 (EDA-A2), a member of the TNF family that is encoded by the anhidrotic ectodermal dysplasia (EDA) gene. Although XEDAR was first described in the year 2000, its function and molecular mechanism of action is still largely unclear. XEDAR has been reported to activate canonical nuclear factor κB (NF-κB) signaling and mitogen-activated protein (MAP) kinases. Here we report that XEDAR is also able to trigger the non-canonical NF-κB pathway, characterized by the processing of p100 (NF-κB2) into p52, followed by nuclear translocation of p52 and RelB. We provide evidence that XEDAR-induced p100 processing relies on the binding of XEDAR to TRAF3 and TRAF6, and requires the kinase activity of NIK and IKKα. We also show that XEDAR stimulation results in NIK accumulation and that p100 processing is negatively regulated by TRAF3, cIAP1 and A20. - Highlights: • XEDAR activates the non-canonical NF-κB pathway. • XEDAR-induced processing of p100 depends on XEDAR interaction with TRAF3 and TRAF6. • XEDAR-induced processing of p100 depends on NIK and IKKα activity. • Overexpression of XEDAR leads to NIK accumulation. • XEDAR-induced processing of p100 is negatively regulated by TRAF3 cIAP1 and A20.

Molecular Determinants of Hormone-Refractory Prostate Cancer

Science.gov (United States)

2015-07-01

Suzuki Y, Honda G, et al. Large-scale identification and characterization of human genes that activate NF- kappaB and MAPK signaling pathways. Oncogene...2003 May 22;22(21):3307-18. Mendiratta P, et al. Genomic strategy for targeting therapy in castration-resistant prostate cancer. J Clin Oncol. 2009 Apr

Bcl10 links saturated fat overnutrition with hepatocellular NF-kB activation and insulin resistance

NARCIS (Netherlands)

Beek, M.H. van; Oravecz-Wilson, K.I.; Delekta, P.C.; Gu, S.; Li, X.; Jin, X.; Apel, I.J.; Konkle, K.S.; Feng, Y.; Teitelbaum, D.H.; Ruland, J.; McAllister-Lucas, L.M.; Lucas, P.C.

2012-01-01

Excess serum free fatty acids (FFAs) are fundamental to the pathogenesis of insulin resistance. With high-fat feeding, FFAs activate NF-kB in target tissues, initiating negative crosstalk with insulin signaling. However, the mechanisms underlying FFA-dependent NF-kB activation remain unclear. Here,

Tumor necrosis factor α triggers proliferation of adult neural stem cells via IKK/NF-κB signaling

Directory of Open Access Journals (Sweden)

Kaltschmidt Christian

2006-09-01

Full Text Available Abstract Background Brain inflammation has been recognized as a complex phenomenon with numerous related aspects. In addition to the very well-described neurodegenerative effect of inflammation, several studies suggest that inflammatory signals exert a potentially positive influence on neural stem cell proliferation, migration and differentiation. Tumor necrosis factor alpha (TNF-α is one of the best-characterized mediators of inflammation. To date, conclusions about the action of TNF on neural stem or progenitor cells (NSCs, NPCs have been conflicting. TNF seems to activate NSC proliferation and to inhibit their differentiation into NPCs. The purpose of the present study was to analyze the molecular signal transduction mechanisms induced by TNF and resulting in NSC proliferation. Results Here we describe for the first time the TNF-mediated signal transduction cascade in neural stem cells (NSCs that results in increased proliferation. Moreover, we demonstrate IKK-α/β-dependent proliferation and markedly up-regulated cyclin D1 expression after TNF treatment. The significant increase in proliferation in TNF-treated cells was indicated by increased neurosphere volume, increased bromodeoxyuridin (BrdU incorporation and a higher total cell number. Furthermore, TNF strongly activated nuclear factor-kappa B (NF-κB as measured by reporter gene assays and by an activity-specific antibody. Proliferation of control and TNF-treated NSCs was strongly inhibited by expression of the NF-κB super-repressor IκB-AA1. Pharmacological blockade of IκB ubiquitin ligase activity led to comparable decreases in NF-κB activity and proliferation. In addition, IKK-β gene product knock-down via siRNA led to diminished NF-κB activity, attenuated cyclin D1 expression and finally decreased proliferation. In contrast, TGFβ-activated kinase 1 (TAK-1 is partially dispensable for TNF-mediated and endogenous proliferation. Understanding stem cell proliferation is crucial

ß-Hydroxybutyrate Activates the NF-κB Signaling Pathway to Promote the Expression of Pro-Inflammatory Factors in Calf Hepatocytes

Directory of Open Access Journals (Sweden)

Xiaoxia Shi

2014-01-01

Full Text Available Background/Aims: ß-hydroxybutyrate (BHBA is the major component of ketone bodies in ketosis. Dairy cows with ketosis often undergo oxidative stress. BHBA is related to the inflammation involved in other diseases of dairy cattle. However, whether BHBA can induce inflammatory injury in dairy cow hepatocytes and the potential mechanism of this induction are not clear. The NF-κB pathway plays a vital role in the inflammatory response. Methods: Therefore, this study evaluated the oxidative stress, pro-inflammatory factors and NF-κB pathway in cultured calf hepatocytes treated with different concentrations of BHBA, pyrrolidine dithiocarbamate (PDTC, an NF-κB pathway inhibitor and N-acetylcysteine (NAC, antioxidant. Results: The results showed that BHBA could significantly increase the levels of oxidation indicators (MDA, NO and iNOS, whereas the levels of antioxidation indicators (GSH-Px, CAT and SOD were markedly decreased in hepatocytes. The IKKß activity and phospho-IκBa (p-IκBa contents were increased in BHBA-treated hepatocytes. This increase was accompanied by the increased expression level and transcription activity of p65. The expression levels of NF-κB-regulated inflammatory cytokines, namely TNF-a, IL-6 and IL-1ß, were markedly increased after BHBA treatment, while significantly decreased after NAC treatment. However, the p-IκBa level and the expression and activity of p65 and its target genes were markedly decreased in the PDTC + BHBA group compared with the BHBA (1.8 mM group. Moreover, immunocytofluorescence of p65 showed a similar trend. Conclusion: The present data indicate that higher concentrations of BHBA can induce cattle hepatocyte inflammatory injury through the NF-κB signaling pathway, which may be activated by oxidative stress.

Effects of acteoside on lipopolysaccharide-induced inflammation in acute lung injury via regulation of NF-κB pathway in vivo and in vitro

Energy Technology Data Exchange (ETDEWEB)

Jing, Wang; Chunhua, Ma, E-mail: machunhuabest@126.com; Shumin, Wang, E-mail: wangshuminch@126.com

2015-06-01

The purpose of the present study was to investigate the protective role of acteoside (AC) on lipopolysaccharide (LPS)-induced acute lung injury (ALI). BalB/c mice intraperitoneally received AC (30, and 60 mg/kg) or dexamethasone (2 mg/kg) 2 h prior to or after intratracheal instillation of LPS. Treatment with AC significantly decreased lung wet-to-dry weight (W/D) ratio and lung myeloperoxidase (MPO) activity and ameliorated LPS-induced lung histopathological changes. In addition, AC increased super oxide dismutase (SOD) level and inhibited malondialdehyde (MDA) content, total cell and neutrophil infiltrations, and levels of proinflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) in LPS-stimulated mice. Furthermore, we demonstrated that AC inhibited the phosphorylation of IκBα, nuclear factor-κB (NF-κB) p65, inhibitor of nuclear factor kappa-B kinase-α (IKK-α) and inhibitor of nuclear factor kappa-B kinase-β (IKKβ) in LPS-induced inflammation in A549 cells. Our data suggested that LPS evoked the inflammatory response in lung epithelial cells A549. The experimental results indicated that the protective mechanism of AC might be attributed partly to the inhibition of proinflammatory cytokine production and NF-κB activation. - Highlights: • Acteoside inhibited inflammation in LPS-induced lung injury in mice. • Acteoside inhibited inflammation in lung epithelial cells A549. • Acteoside inhibited NF-kB activation in LPS-induced mice and lung epithelial cells A549.

Lentiviral-mediated targeted NF-kappaB blockade in dorsal spinal cord glia attenuates sciatic nerve injury-induced neuropathic pain in the rat.

Science.gov (United States)

Meunier, Alice; Latrémolière, Alban; Dominguez, Elisa; Mauborgne, Annie; Philippe, Stéphanie; Hamon, Michel; Mallet, Jacques; Benoliel, Jean-Jacques; Pohl, Michel

2007-04-01

Neuropathic pain developing after peripheral nerve injury is associated with altered neuronal and glial cell functions in the spinal cord. Activated glia produces algogenic mediators, exacerbating pain. Among the different intracellular pathways possibly involved in the modified glial function, the nuclear factor kappaB (NF-kappaB) system is of particular interest, as numerous genes encoding inflammation- and pain-related molecules are controlled by this transcription factor. NF-kappaB is a pleiotropic factor also involved in central nervous system homeostasy. To study its role in chronic pain, it is thus essential to inhibit the NF-kappaB pathway selectively in activated spinal glial cells. Here, we show that when restricted to spinal cord and targeted to glial cells, lentiviral vector-mediated delivery of NF-kappaB super- repressor IkappaBalpha resulted in an inhibition of the NF-kappaB pathway activated in the rat spinal cord after sciatic nerve injury (chronic constriction injury, CCI). Concomitantly, IkappaBalpha overproduction prevented the enhanced expression of interleukin-6 and of inducible nitric oxide synthase associated with chronic constriction injury and resulted in prolonged antihyperalgesic and antiallodynic effects. These data show that targeted blockade of NF-kappaB activity in spinal glia efficiently alleviates pain behavior in CCI rats, demonstrating the active participation of the glial NF-kappaB pathway in the development of neuropathic pain after peripheral nerve injury.

BFV activates the NF-κB pathway through its transactivator (BTas) to enhance viral transcription

International Nuclear Information System (INIS)

Wang Jian; Tan Juan; Zhang Xihui; Guo Hongyan; Zhang Qicheng; Guo Tingting; Geng Yunqi; Qiao Wentao

2010-01-01

Multiple families of viruses have evolved sophisticated strategies to regulate nuclear factor-κB (NF-κB) signaling, which plays a pivotal role in diverse cellular events, including virus-host interactions. In this study, we report that bovine foamy virus (BFV) is able to activate the NF-κB pathway through the action of its transactivator, BTas. Both cellular IKKβ and IκBα also participate in this activation. In addition, we demonstrate that BTas induces the processing of p100, which implies that BTas can activate NF-κB through a noncanonical pathway as well. Co-immunoprecipitation analysis shows that BTas interacts with IKK catalytic subunits (IKKα and IKKβ), which may be responsible for regulation of IKK kinase activity and persistent NF-κB activation. Furthermore, our results indicate that the level of BTas-mediated LTR transcription correlates with the activity of cellular NF-κB. Together, this study suggests that BFV activates the NF-κB pathway through BTas to enhance viral transcription.

Regulation of NF-κB activity in astrocytes: effects of flavonoids at dietary-relevant concentrations

International Nuclear Information System (INIS)

Spilsbury, Alison; Vauzour, David; Spencer, Jeremy P.E.; Rattray, Marcus

2012-01-01

Highlights: ► We tested the hypothesis that low concentrations of flavonoids inhibit NF-κB in astrocytes. ► Primary cultured astrocytes possess a functional κB-system, measured using luciferase assays. ► Seven flavonoids (100 nM–1 μM) failed to reduce NF-κB activity in astrocytes. ► Four flavonoids (100 nM–1 μM) failed to reduce TNFa-stimulated NF-κB activity in astrocytes. ► (−)-Epicatechin did not regulate nuclear translocation of the NF-κB subunit, p65. -- Abstract: Neuroinflammation plays an important role in the progression of neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease. Sustained activation of nuclear transcription factor κB (NF-κB) is thought to play an important role in the pathogenesis of neurodegenerative disorders. Flavonoids have been shown to possess antioxidant and anti-inflammatory properties and we investigated whether flavonoids, at submicromolar concentrations relevant to their bioavailability from the diet, were able to modulate NF-κB signalling in astrocytes. Using luciferase reporter assays, we found that tumour necrosis factor (TNFα, 150 ng/ml) increased NF-κB-mediated transcription in primary cultures of mouse cortical astrocytes, which was abolished on co-transfection of a dominant-negative IκBα construct. In addition, TNFα increased nuclear localisation of p65 as shown by immunocytochemistry. To investigate potential flavonoid modulation of NF-κB activity, astrocytes were treated with flavonoids from different classes; flavan-3-ols ((−)-epicatechin and (+)-catechin), flavones (luteolin and chrysin), a flavonol (kaempferol) or the flavanones (naringenin and hesperetin) at dietary-relevant concentrations (0.1–1 μM) for 18 h. None of the flavonoids modulated constitutive or TNFα-induced NF-κB activity. Therefore, we conclude that NF-κB signalling in astrocytes is not a major target for flavonoids.

Immunodeficiency associated with a nonsense mutation of IKBKB

DEFF Research Database (Denmark)

Nielsen, Christian; Jakobsen, Marianne A; Larsen, Martin Jakob

2014-01-01

We report an infant of consanguineous parents of Turkish decent with a novel immunodeficiency associated with homozygosity for a nonsense mutation of the gene encoding Inhibitor of nuclear factor kappa-B (NF-κB) kinase subunit beta (IKKβ). At five months, she presented with respiratory insufficie......We report an infant of consanguineous parents of Turkish decent with a novel immunodeficiency associated with homozygosity for a nonsense mutation of the gene encoding Inhibitor of nuclear factor kappa-B (NF-κB) kinase subunit beta (IKKβ). At five months, she presented with respiratory...... no explanation before whole exome sequencing revealed a novel mutation abrogating signaling through the canonical NF-κB pathway....

Unirradiated cells rescue cells exposed to ionizing radiation: Activation of NF-κB pathway in irradiated cells

Energy Technology Data Exchange (ETDEWEB)

Lam, R.K.K. [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Han, Wei [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong (Hong Kong)

2015-12-15

Highlights: • Rescue effect was observed in both irradiated and HeLa and NIH/3T3 cells. • Novel setup and procedures to separate the rescue signals and the bystander signals. • Confirmed activation of NF-κB pathway in rescue effect using activation inhibitor. • Confirmed activation of NF-κB pathway in rescue effect using anti-NF-κB p65 antibody. - Abstract: We studied the involvement of NF-κB pathway activation in the rescue effect in HeLa and NIH/3T3 cells irradiated by α particles. Firstly, upon irradiation by 5 cGy of α particles, for both cell lines, the numbers of 53BP1 foci/cell at 12 h post-irradiation were significantly smaller when only 2.5% of the cell population was irradiated as compared to 100% irradiation, which demonstrated the rescue effect. Secondly, we studied the effect of NF-κB on the rescue effect through the use of the NF-κB activation inhibitor BAY-11-7082. Novel experimental setup and procedures were designed to prepare the medium (CM) which had conditioned the bystander cells previously partnered with irradiated cells, to ensure physical separation between rescue and bystander signals. BAY-11-7082 itself did not inflict DNA damages in the cells or have effects on activation of the NF-κB response pathway in the irradiated cells through direct irradiation. The rescue effect was induced in both cell lines by the CM, which was abrogated if BAY-11-7082 was added to the CM. Thirdly, we studied the effect of NF-κB on the rescue effect through staining for phosphorylated NF-κB (p-NF-κB) expression using the anti-NF-κB p65 (phospho S536) antibody. When the fraction of irradiated cells dropped from 100% to 2.5%, the p-NF-κB expression in the cell nuclei of irradiated NIH/3T3 cells increased significantly, while that in the cell nuclei of irradiated HeLa cells also increased although not significantly. Moreover, the p-NF-κB expression in the cell nuclei of irradiated HeLa cells and NIH/3T3 cells treated with CM also increased

Airway epithelial NF-κB activation promotes Mycoplasma pneumoniae clearance in mice.

Directory of Open Access Journals (Sweden)

Di Jiang

Full Text Available Respiratory infections including atypical bacteria Mycoplasma pneumoniae (Mp contribute to the pathobiology of asthma and chronic obstructive pulmonary disease (COPD. Mp infection mainly targets airway epithelium and activates various signaling pathways such as nuclear factor κB (NF-κB. We have shown that short palate, lung, and nasal epithelium clone 1 (SPLUNC1 serves as a novel host defense protein and is up-regulated upon Mp infection through NF-κB activation in cultured human and mouse primary airway epithelial cells. However, the in vivo role of airway epithelial NF-κB activation in host defense against Mp infection has not been investigated. In the current study, we investigated the effects of in vivo airway epithelial NF-κB activation on lung Mp clearance and its association with airway epithelial SPLUNC1 expression.Non-antimicrobial tetracycline analog 9-t-butyl doxycycline (9-TB was initially optimized in mouse primary tracheal epithelial cell culture, and then utilized to induce in vivo airway epithelial specific NF-κB activation in conditional NF-κB transgenic mice (CC10-(CAIKKβ with or without Mp infection. Lung Mp load and inflammation were evaluated, and airway epithelial SPLUNC1 protein was examined by immunohistochemistry. We found that 9-TB treatment in NF-κB transgene positive (Tg+, but not transgene negative (Tg- mice significantly reduced lung Mp load. Moreover, 9-TB increased airway epithelial SPLUNC1 protein expression in NF-κB Tg+ mice.By using the non-antimicrobial 9-TB, our study demonstrates that in vivo airway epithelial NF-κB activation promotes lung bacterial clearance, which is accompanied by increased epithelial SPLUNC1 expression.

1,25-dihydroxyvitamin D3 impairs NF-κB activation in human naive B cells

International Nuclear Information System (INIS)

Geldmeyer-Hilt, Kerstin; Heine, Guido; Hartmann, Bjoern; Baumgrass, Ria; Radbruch, Andreas; Worm, Margitta

2011-01-01

Highlights: → In naive B cells, VDR activation by calcitriol results in reduced NF-κB p105 and p50 protein expression. → Ligating the VDR with calcitriol causes reduced nuclear translocation of NF-κB p65. → Reduced nuclear amount of p65 after calcitriol incubation results in reduced binding of p65 on the p105 promoter. → Thus, vitamin D receptor signaling may reduce or prevent activation of B cells and unwanted immune responses, e.g. in IgE dependent diseases such as allergic asthma. -- Abstract: 1α,25-dihydroxyvitamin D 3 (calcitriol), the bioactive metabolite of vitamin D, modulates the activation and inhibits IgE production of anti-CD40 and IL-4 stimulated human peripheral B cells. Engagement of CD40 results in NF-κB p50 activation, which is essential for the class switch to IgE. Herein, we investigated by which mechanism calcitriol modulates NF-κB mediated activation of human naive B cells. Naive B cells were predominantly targeted by calcitriol in comparison with memory B cells as shown by pronounced induction of the VDR target gene cyp24a1. Vitamin D receptor activation resulted in a strongly reduced p105/p50 protein and mRNA expression in human naive B cells. This effect is mediated by impaired nuclear translocation of p65 and consequently reduced binding of p65 to its binding site in the p105 promoter. Our data indicate that the vitamin D receptor reduces NF-κB activation by interference with NF-κB p65 and p105. Thus, the vitamin D receptor inhibits costimulatory signal transduction in naive B cells, namely by reducing CD40 signaling.

Methylation-Dependent Activation of CDX1 through NF-κB

Science.gov (United States)

Rau, Tilman T.; Rogler, Anja; Frischauf, Myrjam; Jung, Andreas; Konturek, Peter C.; Dimmler, Arno; Faller, Gerhard; Sehnert, Bettina; El-Rifai, Wael; Hartmann, Arndt; Voll, Reinhard E.; Schneider-Stock, Regine

2013-01-01

The caudal homeobox factor 1 (CDX1) is an essential transcription factor for intestinal differentiation. Its aberrant expression in intestinal metaplasia of the upper gastrointestinal tract is a hallmark within the gastritis-metaplasia-carcinoma sequence. CDX1 expression is influenced by certain pathways, such as Wnt, Ras, or NF-κB signaling; however, these pathways alone cannot explain the transient expression of CDX1 in intestinal metaplasia or the molecular inactivation mechanism of its loss in cases of advanced gastric cancer. In this study, we investigated the epigenetic inactivation of CDX1 by promoter methylation, as well as the functional link of CDX1 promoter methylation to the inflammatory NF-κB signaling pathway. We identified methylation-dependent NF-κB binding to the CDX1 promoter and quantified it using competitive electrophoretic mobility shift assays and chromatin immunoprecipitation. A methylated CDX1 promoter was associated with closed chromatin structure, reduced NF-κB binding, and transcriptional silencing. Along the gastritis-metaplasia-carcinoma sequence, we observed a biphasic pattern of tumor necrosis factor-α (TNF-α) protein expression and an inverse biphasic pattern of CDX1 promoter methylation; both are highly consistent with CDX1 protein expression. The stages of hyper-, hypo-, and hyper-methylation patterns of the CDX1 promoter were inversely correlated with the NF-κB signaling activity along this sequence. In conclusion, these functionally interacting events drive CDX1 expression and contribute to intestinal metaplasia, epithelial dedifferentiation, and carcinogenesis in the human stomach. PMID:22749770

Integrated proteomics identified novel activation of dynein IC2-GR-COX-1 signaling in neurofibromatosis type I (NF1) disease model cells.

Science.gov (United States)

Hirayama, Mio; Kobayashi, Daiki; Mizuguchi, Souhei; Morikawa, Takashi; Nagayama, Megumi; Midorikawa, Uichi; Wilson, Masayo M; Nambu, Akiko N; Yoshizawa, Akiyasu C; Kawano, Shin; Araki, Norie

2013-05-01

Neurofibromatosis type 1 (NF1) tumor suppressor gene product, neurofibromin, functions in part as a Ras-GAP, and though its loss is implicated in the neuronal abnormality of NF1 patients, its precise cellular function remains unclear. To study the molecular mechanism of NF1 pathogenesis, we prepared NF1 gene knockdown (KD) PC12 cells, as a NF1 disease model, and analyzed their molecular (gene and protein) expression profiles with a unique integrated proteomics approach, comprising iTRAQ, 2D-DIGE, and DNA microarrays, using an integrated protein and gene expression analysis chart (iPEACH). In NF1-KD PC12 cells showing abnormal neuronal differentiation after NGF treatment, of 3198 molecules quantitatively identified and listed in iPEACH, 97 molecules continuously up- or down-regulated over time were extracted. Pathway and network analysis further revealed overrepresentation of calcium signaling and transcriptional regulation by glucocorticoid receptor (GR) in the up-regulated protein set, whereas nerve system development was overrepresented in the down-regulated protein set. The novel up-regulated network we discovered, "dynein IC2-GR-COX-1 signaling," was then examined in NF1-KD cells. Validation studies confirmed that NF1 knockdown induces altered splicing and phosphorylation patterns of dynein IC2 isomers, up-regulation and accumulation of nuclear GR, and increased COX-1 expression in NGF-treated cells. Moreover, the neurite retraction phenotype observed in NF1-KD cells was significantly recovered by knockdown of the dynein IC2-C isoform and COX-1. In addition, dynein IC2 siRNA significantly inhibited nuclear translocation and accumulation of GR and up-regulation of COX-1 expression. These results suggest that dynein IC2 up-regulates GR nuclear translocation and accumulation, and subsequently causes increased COX-1 expression, in this NF1 disease model. Our integrated proteomics strategy, which combines multiple approaches, demonstrates that NF1-related neural

Diisononyl phthalate aggravates allergic dermatitis by activation of NF-kB.

Science.gov (United States)

Kang, Jun; Song, Jing; Shen, Shiping; Li, Baizhan; Yang, Xu; Chen, Mingqing

2016-12-20

Several epidemiological studies have suggested a possible link between exposure to Diisononyl phthalate (DINP) and the development of allergies. These findings remain controversial since there is insufficient scientific evidence to assess the ability of DINP to influence allergic immune responses. In addition, the mechanisms behind DINP-caused allergic diseases have not been fully elucidated. In this study, Balb/c mice were orally exposed to DINP for 3 weeks and were then sensitized with fluorescein isothiocyanate (FITC). We showed that oral exposure to DINP could aggravate allergic-dermatitis-like lesions, indicated by an increase in the number of mast cells, and in increased skin edema in FITC-induced contact hypersensitivity. This deterioration was concomitant with increased total serum immunoglobulin-E and Th2 cytokines. We determined the oxidative damage and the activation of nuclear factor-kb (NF-kB). The data demonstrated that DINP could promote oxidative damage and the activation of NF-kB in the skin. The expression of thymic stromal lymphopoietin and the activation of signal transducer and activator of transcriptions 3, 5 and 6 were enhanced concomitant with exacerbated allergic dermatitis effects and the activation of NF-kB induced by DINP. These effects were alleviated by pyrollidine dithiocarbamate, an inhibitor of NF-kB. The results suggest that oral exposure to DINP aggravated allergic contact dermatitis, which was positively regulated via NF-kB.

Anesthetic propofol reduces endotoxic inflammation by inhibiting reactive oxygen species-regulated Akt/IKKβ/NF-κB signaling.

Directory of Open Access Journals (Sweden)

Chung-Hsi Hsing

Full Text Available BACKGROUND: Anesthetic propofol has immunomodulatory effects, particularly in the area of anti-inflammation. Bacterial endotoxin lipopolysaccharide (LPS induces inflammation through toll-like receptor (TLR 4 signaling. We investigated the molecular actions of propofol against LPS/TLR4-induced inflammatory activation in murine RAW264.7 macrophages. METHODOLOGY/PRINCIPAL FINDINGS: Non-cytotoxic levels of propofol reduced LPS-induced inducible nitric oxide synthase (iNOS and NO as determined by western blotting and the Griess reaction, respectively. Propofol also reduced the production of tumor necrosis factor-α (TNF-α, interleukin (IL-6, and IL-10 as detected by enzyme-linked immunosorbent assays. Western blot analysis showed propofol inhibited LPS-induced activation and phosphorylation of IKKβ (Ser180 and nuclear factor (NF-κB (Ser536; the subsequent nuclear translocation of NF-κB p65 was also reduced. Additionally, propofol inhibited LPS-induced Akt activation and phosphorylation (Ser473 partly by reducing reactive oxygen species (ROS generation; inter-regulation that ROS regulated Akt followed by NF-κB activation was found to be crucial for LPS-induced inflammatory responses in macrophages. An in vivo study using C57BL/6 mice also demonstrated the anti-inflammatory properties against LPS in peritoneal macrophages. CONCLUSIONS/SIGNIFICANCE: These results suggest that propofol reduces LPS-induced inflammatory responses in macrophages by inhibiting the interconnected ROS/Akt/IKKβ/NF-κB signaling pathways.

Anesthetic Propofol Reduces Endotoxic Inflammation by Inhibiting Reactive Oxygen Species-regulated Akt/IKKβ/NF-κB Signaling

Science.gov (United States)

Hsing, Chung-Hsi; Lin, Ming-Chung; Choi, Pui-Ching; Huang, Wei-Ching; Kai, Jui-In; Tsai, Cheng-Chieh; Cheng, Yi-Lin; Hsieh, Chia-Yuan; Wang, Chi-Yun; Chang, Yu-Ping; Chen, Yu-Hong; Chen, Chia-Ling; Lin, Chiou-Feng

2011-01-01

Background Anesthetic propofol has immunomodulatory effects, particularly in the area of anti-inflammation. Bacterial endotoxin lipopolysaccharide (LPS) induces inflammation through toll-like receptor (TLR) 4 signaling. We investigated the molecular actions of propofol against LPS/TLR4-induced inflammatory activation in murine RAW264.7 macrophages. Methodology/Principal Findings Non-cytotoxic levels of propofol reduced LPS-induced inducible nitric oxide synthase (iNOS) and NO as determined by western blotting and the Griess reaction, respectively. Propofol also reduced the production of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 as detected by enzyme-linked immunosorbent assays. Western blot analysis showed propofol inhibited LPS-induced activation and phosphorylation of IKKβ (Ser180) and nuclear factor (NF)-κB (Ser536); the subsequent nuclear translocation of NF-κB p65 was also reduced. Additionally, propofol inhibited LPS-induced Akt activation and phosphorylation (Ser473) partly by reducing reactive oxygen species (ROS) generation; inter-regulation that ROS regulated Akt followed by NF-κB activation was found to be crucial for LPS-induced inflammatory responses in macrophages. An in vivo study using C57BL/6 mice also demonstrated the anti-inflammatory properties against LPS in peritoneal macrophages. Conclusions/Significance These results suggest that propofol reduces LPS-induced inflammatory responses in macrophages by inhibiting the interconnected ROS/Akt/IKKβ/NF-κB signaling pathways. PMID:21408125

NF-kappaB in Lung Tumorigenesis

International Nuclear Information System (INIS)

Cai, Zhenjian; Tchou-Wong, Kam-Meng; Rom, William N.

2011-01-01

The development of lung cancer in humans can be divided into three steps initiation, promotion and progression. This process is driven by alterations in related signal transduction pathways. These pathways signal the aberrant activation of NF-kappaB, a transcription factor that regulates the expression of genes important for lung tumorigenesis. Our current knowledge about the role of the NF-kappaB signaling pathway in the development of lung cancer has been bolstered by animal models demonstrating the connection between K-ras and tobacco induced lung transformation with NF-kappaB. Activation of downstream genes leads to cell proliferation, inhibition of apoptosis, angiogenesis, inflammation, invasion, and metastasis

NF-kappaB in Lung Tumorigenesis

Energy Technology Data Exchange (ETDEWEB)

Cai, Zhenjian [Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, New York University School of Medicine, 462 First Avenue, NBV 7N24, New York, NY 10016 (United States); Tchou-Wong, Kam-Meng; Rom, William N., E-mail: william.rom@nyumc.org [Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, New York University School of Medicine, 462 First Avenue, NBV 7N24, New York, NY 10016 (United States); Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987 (United States)

2011-12-14

The development of lung cancer in humans can be divided into three steps initiation, promotion and progression. This process is driven by alterations in related signal transduction pathways. These pathways signal the aberrant activation of NF-kappaB, a transcription factor that regulates the expression of genes important for lung tumorigenesis. Our current knowledge about the role of the NF-kappaB signaling pathway in the development of lung cancer has been bolstered by animal models demonstrating the connection between K-ras and tobacco induced lung transformation with NF-kappaB. Activation of downstream genes leads to cell proliferation, inhibition of apoptosis, angiogenesis, inflammation, invasion, and metastasis.

1,25-dihydroxyvitamin D{sub 3} impairs NF-{kappa}B activation in human naive B cells

Energy Technology Data Exchange (ETDEWEB)

Geldmeyer-Hilt, Kerstin, E-mail: kerstin.hilt@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Heine, Guido, E-mail: guido.heine@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Hartmann, Bjoern, E-mail: bjoern.hartmann@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany); Baumgrass, Ria, E-mail: baumgrass@drfz.de [Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Radbruch, Andreas, E-mail: radbruch@drfz.de [Deutsches Rheuma-Forschungszentrum Berlin, Chariteplatz 1, 10117 Berlin (Germany); Worm, Margitta, E-mail: margitta.worm@charite.de [Allergie-Centrum-Charite, CCM, Klinik fuer Dermatologie und Allergologie, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, 10117 Berlin (Germany)

2011-04-22

Highlights: {yields} In naive B cells, VDR activation by calcitriol results in reduced NF-{kappa}B p105 and p50 protein expression. {yields} Ligating the VDR with calcitriol causes reduced nuclear translocation of NF-{kappa}B p65. {yields} Reduced nuclear amount of p65 after calcitriol incubation results in reduced binding of p65 on the p105 promoter. {yields} Thus, vitamin D receptor signaling may reduce or prevent activation of B cells and unwanted immune responses, e.g. in IgE dependent diseases such as allergic asthma. -- Abstract: 1{alpha},25-dihydroxyvitamin D{sub 3} (calcitriol), the bioactive metabolite of vitamin D, modulates the activation and inhibits IgE production of anti-CD40 and IL-4 stimulated human peripheral B cells. Engagement of CD40 results in NF-{kappa}B p50 activation, which is essential for the class switch to IgE. Herein, we investigated by which mechanism calcitriol modulates NF-{kappa}B mediated activation of human naive B cells. Naive B cells were predominantly targeted by calcitriol in comparison with memory B cells as shown by pronounced induction of the VDR target gene cyp24a1. Vitamin D receptor activation resulted in a strongly reduced p105/p50 protein and mRNA expression in human naive B cells. This effect is mediated by impaired nuclear translocation of p65 and consequently reduced binding of p65 to its binding site in the p105 promoter. Our data indicate that the vitamin D receptor reduces NF-{kappa}B activation by interference with NF-{kappa}B p65 and p105. Thus, the vitamin D receptor inhibits costimulatory signal transduction in naive B cells, namely by reducing CD40 signaling.

Chikusetsu saponin IVa ameliorates high fat diet-induced inflammation in adipose tissue of mice through inhibition of NLRP3 inflammasome activation and NF-κB signaling.

Science.gov (United States)

Yuan, Chengfu; Liu, Chaoqi; Wang, Ting; He, Yumin; Zhou, Zhiyong; Dun, Yaoyan; Zhao, Haixia; Ren, Dongming; Wang, Junjie; Zhang, Changcheng; Yuan, Ding

2017-05-09

Chronic metabolic inflammation in adipose tissue plays an important role in the development of obesity-associated diseases. Our previous study indicated that total saponins of Panax japonicus (SPJ) rhizoma and Chikusetsu saponin V, one main component of SPJ, could exert the anti-oxidative and anti-inflammatory effects. The present study aimed to investigate the in vivo and Ex vivo anti-inflammatory activities of another main component of SPJ, namely Chikusetsu saponin IVa (CS). CS could significantly inhibited HFD-induced lipid homeostasis, and inhibited inflammation in adipose tissue, as reflected by the decreased mRNA expression levels of inflammation-related genes and secretion of the chemokines/cytokines, inhibited the accumulation of adipose tissue macrophages (ATMs) and shifted their polarization from M1 to M2, suppressed HFD-induced expression of NLRP3 inflammasome component genes and decreased IL-1β and Caspase-1 production in mice. Moreover, CS treatment also inhibited the activation of NLRP3 inflammasome in bone marrow-derived macrophages (BMDMs). Meanwhile, CS treatment inhibited an NLRP3-induced ASC pyroptosome formation and lipopolysaccharide (LPS)-induced pyroptosis. Furthermore, CS treatment suppressed HFD-induced NF-κB signaling in vivo and LPS-induced NF-κB activation as reflected by the fact that their phosphorylated forms and the ratios of pNF-κB/NF-κB, pIKK/IKK, and pIκB/IκB were all decreased in EAT from HFD-fed mice treated with CS as compared with those of HFD mice. Taking together, this study has revealed that CS effectively inhibits HFD-induced inflammation in adipose tissue of mice through inhibiting both NLRP3 inflammasome activation and NF-κB signaling. Thus, CS can serve as a potential therapeutic drug in the prevention and treatment of inflammation-associated diseases.

Nf2-Yap signaling controls the expansion of DRG progenitors and glia during DRG development.

Science.gov (United States)

Serinagaoglu, Yelda; Paré, Joshua; Giovannini, Marco; Cao, Xinwei

2015-02-01

Molecular mechanisms governing the maintenance and proliferation of dorsal root ganglia (DRG) progenitors are largely unknown. Here we reveal that the Hippo pathway regulates the expansion of DRG progenitors and glia during mammalian DRG development. The key effectors of this pathway, transcriptional coactivators Yap and Taz, are expressed in DRG progenitors and glia during DRG development but are at least partially inhibited from activating transcription. Aberrant YAP activation leads to overexpansion of DRG progenitor and glial populations. We further show that the Neurofibromatosis 2 (Nf2) tumor suppressor inhibits Yap during DRG development. Loss of Nf2 leads to similar phenotypes as does YAP hyperactivation, and deleting Yap suppresses these phenotypes. Our study demonstrates that Nf2-Yap signaling plays important roles in controlling the expansion of DRG progenitors and glia during DRG development. Copyright © 2014 Elsevier Inc. All rights reserved.

Andrographolide Suppress Tumor Growth by Inhibiting TLR4/NF-κB Signaling Activation in Insulinoma

Science.gov (United States)

Zhang, Qian-Qian; Ding, Yi; Lei, Yan; Qi, Cui-Ling; He, Xiao-Dong; Lan, Tian; Li, Jiang-Chao; Gong, Ping; Yang, Xuesong; Geng, Jian-Guo; Wang, Li-Jing

2014-01-01

Insulinomas are rare tumors, and approximately 10% of insulinomas are malignant. Accumulating evidence has implicated that we still lack effective therapy to treat the patients who are diagnosed with rare malignant insulinoma. Previous studies have reported that Andrographolide (Andro) could inhibit cell cycle progression, reduce cell invasion and induce cell apoptosis in many common cancer cells. However, the effects of andro are cell type-dependent. So we emplored the β-TC-6 cells and the RIP1-Tag2 transgenic mouse model of endogenously growing insulinoma model to elucidate the possible anti-cancer effect of Andro on insulinoma, an uncommon type of malignant cancers in this study. Our experiments revealed that Andro significantly inhibited tumor growth at both the early-stage and the advanced-stage of insulinoma through targeting the TLR4/NF-κB signaling pathway. This work initially provides the evidence that the TLR4/NF-κB signaling pathway might be vital as a potential therapeutic target, and also indispensable in Andro-mediated anti-cancer effect in insulinoma. PMID:24719558

Immunomodulatory effect of tea saponin in immune T-cells and T-lymphoma cells via regulation of Th1, Th2 immune response and MAPK/ERK2 signaling pathway.

Science.gov (United States)

Bhardwaj, Jyoti; Chaudhary, Narendra; Seo, Hyo-Jin; Kim, Min-Yong; Shin, Tai-Sun; Kim, Jong-Deog

2014-06-01

The anti-cancer activity of saponins and phenolic compounds present in green tea was previously reported. However, the immunomodulatory and adjuvanticity activity of tea saponin has never been studied. In this study, we investigated the immunomodulatory effect of tea saponin in T-lymphocytes and EL4 cells via regulation of cytokine response and mitogen-activated protein kinases (MAPK) signaling pathway. Quantitative analysis of mRNA expression level of cytokines were performed by reverse transcription polymerase chain reaction following stimulation with tea saponin, ovalbumin (OVA) alone or tea saponin in combination with OVA. Tea saponin inhibited the proliferation of EL4 cells measured in a dose-dependent manner. No cytotoxicity effect of tea saponin was detected in T-lymphocytes; rather, tea saponin enhanced the proliferation of T-lymphocytes. Tea saponin with OVA increased the expression of interleukin (IL)-1, IL-2, IL-12, interferon-γ and tumor necrosis factor (TNF)-α and decreased the expression level of IL-10 and IL-8 in T-lymphocytes. Furthermore, tea saponin, in the presence of OVA, downregulated the MAPK signaling pathway via inhibition of IL-4, IL-8 and nuclear factor kappaB (NF-κB) in EL4 cells. Th1 cytokines enhancer and Th2 cytokines and NF-κB inhibitor, tea saponin can markedly inhibit the proliferation and invasiveness of T-lymphoma (EL4) cells, possibly due to TNF-α- and NF-κB-mediated regulation of MAPK signaling pathway.

Curcumin enhances the radiosensitivity of renal cancer cells by suppressing NF-κB signaling pathway.

Science.gov (United States)

Li, Gang; Wang, Ziming; Chong, Tie; Yang, Jie; Li, Hongliang; Chen, Haiwen

2017-10-01

The radiation resistance of renal cell carcinoma (RCC) remains the primary obstacle to improve patient survival. This study aimed to investigate the effects of curcumin on the radiosensitivity of RCC cells. Human RCC cell (ACHN) was exposed to irradiation (IR) and/or curcumin treatment. Cell viability, DNA repair, cell cycle, and apoptosis, were evaluated by MTT, immunofluoresence staining and flow cytometry. Moreover, ACHN cells were xenografted into nude mice and subjected to IR and/or curcumin treatment. The expression of NF-κB signaling related proteins in ACHN cells and xenografts was detected by western blot analysis. The results showed that curcumin significantly increased radiosensitivity of ACHN cells by inhibiting the cell proliferation and DNA damage repair, causing cell cycle arrest at G2/M phase, inducing apoptosis in vitro, and suppressing the growth of xenografts in vivo. In addition, curcumin enhanced radiosensitivity was through markedly inhibiting IR-induced NF-κB signaling by modulating the related protein expressions including NF-κBP65, I-κB, VEGF, COX2, and Bcl-2 in ACHN cells, which was further strengthened by NF-κB inhibitor PDTC treatment. Thus, curcumin may confer radiosensitivity on RCC via inhibition of NF-κB activation and its downstream regulars, suggesting the potential application of curcumin as an adjuvant in radiotherapy of RCC. Copyright © 2017. Published by Elsevier Masson SAS.

RUNX1: A Regulator of NF-kB Signaling in Pulmonary Diseases.

Science.gov (United States)

Tang, Xiaoju; Sun, Ling; Wang, Gang; Chen, Bojiang; Luo, Fengming

2018-01-01

Runt-related transcription factor 1 (RUNX1), a member of the RUNX family, is one of the key regulatory proteins in vertebrates. RUNX1 is involved in embryonic development, hematopoiesis, angiogenesis, tumorigenesis and immune response. In the past few decades, studies mainly focused on the effect of RUNX1 on acute leukemia and cancer. Only few studies about the function of RUNX1 in the pathological process of pulmonary diseases have been reported. Recent studies have demonstrated that RUNX1 is highly expressed in both mesenchymal and epithelial compartments of the developing and postnatal lung and that it plays a critical role in the lipopolysaccharide induced lung inflammation by regulating the NF-kB pathway. RUNX1 participates in the regulation of the NF-kB signaling pathway through interaction with IkB kinase complex in the cytoplasm or interaction with the NF-kB subunit P50. NF-kB is well-known signaling pathway necessary for inflammatory response in the lung. This review is to highlight the RUNX1 structure, isoforms and to present the mechanism that RUNX1 regulates NF-kB. This will illustrate the great potential role of RUNX1 in the inflammation signaling pathway in pulmonary diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Anti-inflammatory activity of Odina wodier Roxb, an Indian folk remedy, through inhibition of toll-like receptor 4 signaling pathway.

Science.gov (United States)

Ojha, Durbadal; Mukherjee, Hemanta; Mondal, Supriya; Jena, Aditya; Dwivedi, Ved Prakash; Mondal, Keshab C; Malhotra, Bharti; Samanta, Amalesh; Chattopadhyay, Debprasad

2014-01-01

Inflammation is part of self-limiting non-specific immune response, which occurs during bodily injury. In some disorders the inflammatory process becomes continuous, leading to the development of chronic inflammatory diseases including cardiovascular diseases, diabetes, cancer etc. Several Indian tribes used the bark of Odina wodier (OWB) for treating inflammatory disorders. Thus, we have evaluated the immunotherapeutic potential of OWB methanol extract and its major constituent chlorogenic acid (CA), using three popular in vivo antiinflammatory models: Carrageenan- and Dextran-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To elucidate the possible anti-inflammatory mechanism of action we determine the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2), and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-12). Further, we determine the toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 (MyD88), c-Jun N-terminal kinases (JNK), nuclear factor kappa-B cells (NF-κB), and NF-kB inhibitor alpha (IK-Bα) by protein and mRNA expression, and Western blot analysis in drug treated LPS-induced murine macrophage model. Moreover, we determined the acute and sub-acute toxicity of OWB extract in BALB/c mice. Our study demonstrated a significant anti-inflammatory activity of OWB extract and CA along with the inhibition of TNF-α, IL-1β, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-κBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the OWB extract and CA can efficiently inhibit inflammation through the down regulation of TLR4/MyD88/NF-kB signaling pathway.

Anti-inflammatory activity of Odina wodier Roxb, an Indian folk remedy, through inhibition of toll-like receptor 4 signaling pathway.

Directory of Open Access Journals (Sweden)

Durbadal Ojha

Full Text Available Inflammation is part of self-limiting non-specific immune response, which occurs during bodily injury. In some disorders the inflammatory process becomes continuous, leading to the development of chronic inflammatory diseases including cardiovascular diseases, diabetes, cancer etc. Several Indian tribes used the bark of Odina wodier (OWB for treating inflammatory disorders. Thus, we have evaluated the immunotherapeutic potential of OWB methanol extract and its major constituent chlorogenic acid (CA, using three popular in vivo antiinflammatory models: Carrageenan- and Dextran-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To elucidate the possible anti-inflammatory mechanism of action we determine the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2, and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-12. Further, we determine the toll-like receptor 4 (TLR4, Myeloid differentiation primary response gene 88 (MyD88, c-Jun N-terminal kinases (JNK, nuclear factor kappa-B cells (NF-κB, and NF-kB inhibitor alpha (IK-Bα by protein and mRNA expression, and Western blot analysis in drug treated LPS-induced murine macrophage model. Moreover, we determined the acute and sub-acute toxicity of OWB extract in BALB/c mice. Our study demonstrated a significant anti-inflammatory activity of OWB extract and CA along with the inhibition of TNF-α, IL-1β, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-κBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the OWB extract and CA can efficiently inhibit inflammation through the down regulation of TLR4/MyD88/NF-kB signaling pathway.

Inhibition of transcription factor NF-kappaB signaling proteins IKKbeta and p65 through specific cysteine residues by epoxyquinone A monomer: correlation with its anti-cancer cell growth activity.

Science.gov (United States)

Liang, Mei-Chih; Bardhan, Sujata; Pace, Emily A; Rosman, Diana; Beutler, John A; Porco, John A; Gilmore, Thomas D

2006-02-28

Transcription factor NF-kappaB is constitutively active in many human chronic inflammatory diseases and cancers. Epoxyquinone A monomer (EqM), a synthetic derivative of the natural product epoxyquinol A, has previously been shown to be a potent inhibitor of tumor necrosis factor-alpha (TNF-alpha)-induced activation of NF-kappaB, but the mechanism by which EqM inhibits NF-kappaB activation was not known. In this report, we show that EqM blocks activation of NF-kappaB by inhibiting two molecular targets: IkappaB kinase IKKbeta and NF-kappaB subunit p65. EqM inhibits TNF-alpha-induced IkappaBalpha phosphorylation and degradation by targeting IKKbeta, and an alanine substitution for Cys179 in the activation loop of IKKbeta makes it resistant to EqM-mediated inhibition. EqM also directly inhibits DNA binding by p65, but not p50; moreover, replacement of Cys38 in p65 with Ser abolishes EqM-mediated inhibition of DNA binding. Pretreatment of cells with reducing agent dithiothreitol dose-dependently reduces EqM-mediated inhibition of NF-kappaB, further suggesting that EqM directly modifies the thiol group of Cys residues in protein targets. Modifications of the exocyclic alkene of EqM substantially reduce EqM's ability to inhibit NF-kappaB activation. In the human SUDHL-4 lymphoma cell line, EqM inhibits both proliferation and NF-kappaB DNA binding, and activates caspase-3 activity. EqM also effectively inhibits the growth of human leukemia, kidney, and colon cancer cell lines in the NCI's tumor cell panel. Among six colon cancer cell lines, those with low amounts of constitutive NF-kappaB DNA-binding activity are generally more sensitive to growth inhibition by EqM. Taken together, these results suggest that EqM inhibits growth and induces cell death in tumor cells through a mechanism that involves inhibition of NF-kappaB activity at multiple steps in the signaling pathway.

Aconitum pseudo-laeve var. erectum Inhibits Receptor Activator of Nuclear Factor Kappa-B Ligand-Induced Osteoclastogenesis via the c-Fos/nuclear Factor of Activated T-Cells, Cytoplasmic 1 Signaling Pathway and Prevents Lipopolysaccharide-Induced Bone Loss in Mice

Directory of Open Access Journals (Sweden)

Jong Min Baek

2014-08-01

Full Text Available Aconitum pseudo-laeve var. erectum (APE has been widely shown in herbal medicine to have a therapeutic effect on inflammatory conditions. However, there has been no evidence on whether the extract of APE is involved in the biological bone metabolism process, particularly osteoclast-mediated bone resorption. In this study, we confirmed that the administration of APE could restore normal skeletal conditions in a murine model of lipopolysaccharide (LPS-induced bone loss via a decrease in the receptor activator of nuclear factor kappa-B ligand (RANKL/osteoprotegerin (OPG ratio and osteoclast number. We then investigated the effect of APE on the RANKL-induced formation and function of osteoclasts to elucidate its underlying molecular mechanisms. APE suppressed the formation of tartrate-resistant acid phosphatase (TRAP-positive cells, as well as the bone-resorbing activity of mature osteoclasts. Furthermore, APE attenuated nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1 and c-Fos without affecting any early signal pathway of osteoclastogenesis. Subsequently, APE significantly downregulated the expression of various genes exclusively expressed in osteoclasts. These results demonstrate that APE restores LPS-induced bone loss through a decrease of the serum RANKL/OPG ratio, and inhibits osteoclast differentiation and function, suggesting the promise of APE as a potential cure for various osteoclast-associated bone diseases.

NF-κB activation impairs somatic cell reprogramming in ageing.

Science.gov (United States)

Soria-Valles, Clara; Osorio, Fernando G; Gutiérrez-Fernández, Ana; De Los Angeles, Alejandro; Bueno, Clara; Menéndez, Pablo; Martín-Subero, José I; Daley, George Q; Freije, José M P; López-Otín, Carlos

2015-08-01

Ageing constitutes a critical impediment to somatic cell reprogramming. We have explored the regulatory mechanisms that constitute age-associated barriers, through derivation of induced pluripotent stem cells (iPSCs) from individuals with premature or physiological ageing. We demonstrate that NF-κB activation blocks the generation of iPSCs in ageing. We also show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs the generation of iPSCs by eliciting the reprogramming repressor DOT1L, which reinforces senescence signals and downregulates pluripotency genes. Genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo progeria syndrome and Hutchinson-Gilford progeria syndrome patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo extends lifespan and ameliorates the accelerated ageing phenotype of progeroid mice, supporting the interest of studying age-associated molecular impairments to identify targets of rejuvenation strategies.

Low-level laser therapy activates NF-kB via generation of reactive oxygen species in mouse embryonic fibroblasts.

Directory of Open Access Journals (Sweden)

Aaron C-H Chen

Full Text Available Despite over forty years of investigation on low-level light therapy (LLLT, the fundamental mechanisms underlying photobiomodulation at a cellular level remain unclear.In this study, we isolated murine embryonic fibroblasts (MEF from transgenic NF-kB luciferase reporter mice and studied their response to 810 nm laser radiation. Significant activation of NF-kB was observed at fluences higher than 0.003 J/cm(2 and was confirmed by Western blot analysis. NF-kB was activated earlier (1 hour by LLLT compared to conventional lipopolysaccharide treatment. We also observed that LLLT induced intracellular reactive oxygen species (ROS production similar to mitochondrial inhibitors, such as antimycin A, rotenone and paraquat. Furthermore, we observed similar NF-kB activation with these mitochondrial inhibitors. These results, together with inhibition of laser induced NF-kB activation by antioxidants, suggests that ROS play an important role in the laser induced NF-kB signaling pathways. However, LLLT, unlike mitochondrial inhibitors, induced increased cellular ATP levels, which indicates that LLLT also upregulates mitochondrial respiration.We conclude that LLLT not only enhances mitochondrial respiration, but also activates the redox-sensitive NFkB signaling via generation of ROS. Expression of anti-apoptosis and pro-survival genes responsive to NFkB could explain many clinical effects of LLLT.

Lipocalin 2 Suppresses Ocular Inflammation by Inhibiting the Activation of NF-κβ Pathway in Endotoxin-Induced Uveitis

Directory of Open Access Journals (Sweden)

Wenyi Tang

2018-03-01

response by inhibiting the phosphorylation and translocation of NF-κB p65. Conclusions: LCN2 protects against ocular inflammation, at least in part, by negatively regulating the activation of the NF-κB signaling pathway. LCN2 may be a promising anti-inflammatory therapy for ocular diseases, such as uveitis.

IL-17A promotes the migration and invasiveness of cervical cancer cells by coordinately activating MMPs expression via the p38/NF-κB signal pathway.

Directory of Open Access Journals (Sweden)

Minjuan Feng

Full Text Available IL-17A plays an important role in many inflammatory diseases and cancers. We aimed to examine the effect of IL-17A on the invasion of cervical cancer cells and study its related mechanisms.Wound healing and matrigel transwell assays were used to examine the effect of IL-17A on cervical cancer cell migration and invasion by a panel of cervical cancer cell lines. The levels of matrix metalloproteinases (MMPs and tissue inhibitor of metalloproteinases (TIMPs were investigated using western blotting. The activity of p38 and nuclear factor-kappa B (NF-κB signal pathway was detected too.Here, we showed that IL-17A could promote the migration and invasion of cervical cancer cells. Further molecular analysis showed that IL-17A could up-regulate the expressions and activities of MMP2 and MMP9, and down-regulate the expressions of TIMP-1 and TIMP-2. Furthermore, IL-17A also activates p38 signal pathway and increased p50 and p65 nuclear expression. In addition, treatment of cervical cancer cells with the pharmacological p38/NF-κB signal pathway inhibitors, SB203580 and PDTC, potently restored the roles of invasion and upregulation of MMPs induced by IL-17A.IL-17A could promote the migration and invasion of cervical cancer cell via up-regulating MMP2 and MMP9 expression, and down-regulating TIMP-1 and TIMP-2 expression via p38/NF-κB signal pathway. IL-17A may be a potential target to improve the prognosis for patients with cervical cancer.

Correlation of NF-κB signal pathway with tumor metastasis of human head and neck squamous cell carcinoma

International Nuclear Information System (INIS)

Yan, Ming; Xu, Qin; Zhang, Ping; Zhou, Xiao-jian; Zhang, Zhi-yuan; Chen, Wan-tao

2010-01-01

Nuclear factor-kappa B (NF-κB) signaling constitutes a key event in the multistep process of carcinogenesis, progression and treatment in many cancer types. However, the significance of NF-κB pathway for complex and tissue-specific aspects of head and neck cancer progression, such as invasion and metastasis, is less understood. The expression of NF-κB p65 in squamous cell carcinoma of the head and neck (SCCHN) clinical specimens by immunohistochemistry. The role of NF-κB activity in head and neck squamous cell carcinoma was determined by western blot, reporter assay and EMSA analysis in vitro and metastasis assays in vivo in different metastatic potential tumor cells. Furthermore, the apoptosis rate and expression of metastasis-related protein such as MMP9 and VEGF were examined by Annexin V/PI staining and Western blot, respectively. A higher level of active nuclear-localized NF-κB was observed in the metastatic SCCHN specimens group (p < 0.01). The NF-κB activities of SCCHN cell lines with different metastatic potentials were then determined and in excellent agreement with results found in SCCHN specimens, highly metastatic SCCHN cell lines expressed high level of NF-κB activity. The treatment of highly metastatic SCCHN cells with NF-κB inhibitors reduced the in vitro cell invasion capacity of the cells without affecting the apoptotic rate. Additionally, the NF-κB inhibitors significantly inhibited the experimental lung metastasis of Tb cells and lymph node metastasis of TL cells in nude mice. Furthermore, the expression of metastasis-related proteins, such as matrix metalloproteinase 9 and vascular endothelial growth factor, was inhibited by pyrrolidine dithiocarbonate. This study suggests that NF-κB activity significantly contributes to tumor hematologic and lymphatic metastases and may aid in the development of early detection methods or therapies targeting non-conventional molecular targets

Classical and alternative NF-κB signaling cooperate in regulating adipocyte differentiation and function

DEFF Research Database (Denmark)

Weidemann, A.; Lovas, A.; Rauch, A.

2016-01-01

Background and objective:Inflammation of adipose tissue (AT) is a central mediator of insulin resistance. However, the molecular mechanisms triggered by inflammatory cells are not fully understood. The aim of this study was to analyze the metabolic functions of lymphotoxin-β-receptor (LTβ...... to adipocytes. The molecular mechanism was elucidated by chromatin immunoprecipitation and combinatorial treatment with α-LTβR and tumor necrosis factor (TNF).Results:RelB FatKO mice showed improved insulin sensitivity despite increased adiposity and adipocyte hypertrophy. LTβR-induced activation of p52-Rel.......Conclusions:Our data describe an anti-adipogenic action of LTβR signaling and a novel synergism of alternative and classical NF-κB signaling in the regulation of adipocytes. In conclusion, this strong synergism between the two NF-κB pathways shows a method to inhibit adipocyte differentiation and to improve insulin...

Anti-influenza A virus activity of rhein through regulating oxidative stress, TLR4, Akt, MAPK, and NF-κB signal pathways.

Directory of Open Access Journals (Sweden)

Qian-Wen Wang

Full Text Available Rhein, an anthraquinone compound existing in many traditional herbal medicines, has anti-inflammatory, antioxidant, antitumor, antiviral, hepatoprotective, and nephroprotective activities, but its anti-influenza A virus (IAV activity is ambiguous. In the present study, through plaque inhibition assay, time-of-addition assay, antioxidant assay, qRT-PCR, ELISA, and western blotting assays, we investigated the anti-IAV effect and mechanism of action of rhein in vitro and in vivo. The results showed that rhein could significantly inhibit IAV adsorption and replication, decrease IAV-induced oxidative stress, activations of TLR4, Akt, p38, JNK MAPK, and NF-κB pathways, and production of inflammatory cytokines and matrix metalloproteinases in vitro. Oxidant H2O2 and agonists of TLR4, Akt, p38/JNK and IKK/NF-κB could significantly antagonize the inhibitory effects of rhein on IAV-induced cytopathic effect (CPE and IAV replication. Through an in vivo test in mice, we also found that rhein could significantly improve the survival rate, lung index, pulmonary cytokines, and pulmonary histopathological changes. Rhein also significantly decreased pulmonary viral load at a high dose. In conclusion, rhein can inhibit IAV adsorption and replication, and the mechanism of action to inhibit IAV replication may be due to its ability to suppress IAV-induced oxidative stress and activations of TLR4, Akt, p38, JNK MAPK, and NF-κB signal pathways.

Lycopene acts through inhibition of IκB kinase to suppress NF-κB signaling in human prostate and breast cancer cells.

Science.gov (United States)

Assar, Emelia A; Vidalle, Magdalena Castellano; Chopra, Mridula; Hafizi, Sassan

2016-07-01

We studied the effect of the potent dietary antioxidant lycopene on multiple points along the nuclear factor kappa B (NF-κB) signaling pathway in prostate and breast cancer cells. Lycopene significantly inhibited prostate and breast cancer cell growth at physiologically relevant concentrations of ≥1.25 μM. Similar concentrations also caused a 30-40 % reduction in inhibitor of kappa B (IκB) phosphorylation in the cells, as determined by western blotting. Furthermore, the same degree of inhibition by lycopene was observed for NF-κB transcriptional activity, as determined by reporter gene assay. Concomitant with this, immunofluorescence staining of lycopene-treated cells showed a significant suppression (≥25 %) of TNF-induced NF-κB p65 subunit nuclear translocation. Further probing of lycopene's effects on upstream elements of the NF-κB pathway showed a 25 % inhibition of both activity of recombinant IκB kinase β (IKKβ) kinase in a cell-free in vitro assay, as well as activity of IKKβ immunoprecipitated from MDA-MB-231 cells treated with lycopene. In conclusion, the anticancer properties of lycopene may occur through inhibition of the NF-κB signaling pathway, beginning at the early stage of cytoplasmic IKK kinase activity, which then leads to reduced NF-κB-responsive gene regulation. Furthermore, these effects in cancer cells were observed at concentrations of lycopene that are relevant and achievable in vivo.

DMPD: Signaling to NF-kappaB by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available l Med. 2007 Nov;13(11):460-9. Epub 2007 Oct 29. (.png) (.svg) (.html) (.csml) Show Signaling to NF-kappaB by Toll-like receptors. Pub...medID 18029230 Title Signaling to NF-kappaB by Toll-like receptors. Authors Kawai T

TRIM45 negatively regulates NF-κB-mediated transcription and suppresses cell proliferation

International Nuclear Information System (INIS)

Shibata, Mio; Sato, Tomonobu; Nukiwa, Ryota; Ariga, Tadashi; Hatakeyama, Shigetsugu

2012-01-01

Highlights: ► NF-κB plays an important role in cell survival and carcinogenesis. ► TRIM45 negatively regulates TNFα-induced NF-κB-mediated transcription. ► TRIM45 overexpression suppresses cell growth. ► TRIM45 acts as a repressor for the NF-κB signal and regulates cell growth. -- Abstract: The NF-κB signaling pathway plays an important role in cell survival, immunity, inflammation, carcinogenesis, and organogenesis. Activation of NF-κB is regulated by several posttranslational modifications including phosphorylation, neddylation and ubiquitination. The NF-κB signaling pathway is activated by two distinct signaling mechanisms and is strictly modulated by the ubiquitin–proteasome system. It has been reported that overexpression of TRIM45, one of the TRIM family ubiquitin ligases, suppresses transcriptional activities of Elk-1 and AP-1, which are targets of the MAPK signaling pathway. In this study, we showed that TRIM45 also negatively regulates TNFα-induced NF-κB-mediated transcription by a luciferase reporter assay and that TRIM45 lacking a RING domain also has an activity to inhibit the NF-κB signal. Moreover, we found that TRIM45 overexpression suppresses cell growth. These findings suggest that TRIM45 acts as a repressor for the NF-κB signal and regulates cell growth.

NF-κB dependent and independent mechanisms of quartz-induced proinflammatory activation of lung epithelial cells

Directory of Open Access Journals (Sweden)

Schins Roel PF

2010-05-01

Full Text Available Abstract In the initiation and progression of pulmonary inflammation, macrophages have classically been considered as a crucial cell type. However, evidence for the role of epithelial type II cells in pulmonary inflammation has been accumulating. In the current study, a combined in vivo and in vitro approach has been employed to investigate the mechanisms of quartz-induced proinflammatory activation of lung epithelial cells. In vivo, enhanced expression of the inflammation- and oxidative stress-related genes HO-1 and iNOS was found on the mRNA level in rat lungs after instillation with DQ12 respirable quartz. Activation of the classical NF-κB pathway in macrophages and type II pneumocytes was indicated by enhanced immunostaining of phospho-IκBα in these specific lung cell types. In vitro, the direct, particle-mediated effect on proinflammatory signalling in a rat lung epithelial (RLE cell line was compared to the indirect, macrophage product-mediated effect. Treatment with quartz particles induced HO-1 and COX-2 mRNA expression in RLE cells in an NF-κB independent manner. Supernatant from quartz-treated macrophages rapidly activated the NF-κB signalling pathway in RLE cells and markedly induced iNOS mRNA expression up to 2000-fold compared to non-treated control cells. Neutralisation of TNFα and IL-1β in macrophage supernatant did not reduce its ability to elicit NF-κB activation of RLE cells. In addition the effect was not modified by depletion or supplementation of intracellular glutathione. The results from the current work suggest that although both oxidative stress and NF-κB are likely involved in the inflammatory effects of toxic respirable particles, these phenomena can operate independently on the cellular level. This might have consequences for in vitro particle hazard testing, since by focusing on NF-κB signalling one might neglect alternative inflammatory pathways.

A role for NF-κB activity in skin hyperplasia and the development of keratoacanthomata in mice.

Directory of Open Access Journals (Sweden)

Brian Poligone

Full Text Available BACKGROUND: Previous studies have implicated NF-κB signaling in both cutaneous development and oncogenesis. However, these studies have been limited in part by the lethality that results from extreme over- or under-expression of NF-κB in available mouse models. Even cre-driven tissue specific expression of transgenes, or targeted deletion of NF-κB can cause cell death. Therefore, the present study was undertaken to evaluate a novel mouse model of enhanced NF-κB activity in the skin. METHODS: A knock-in homologous recombination technique was utilized to develop a mouse model (referred to as PD mice with increased NF-κB activity. RESULTS: The data show that increased NF-κB activity leads to hyperproliferation and dysplasia of the mouse epidermis. Chemical carcinogenesis in the context of enhanced NF-κB activity promotes the development of keratoacanthomata. CONCLUSION: Our findings support an important role for NF-κB in keratinocyte dysplasia. We have found that enhanced NF-κB activity renders keratinocytes susceptible to hyperproliferation and keratoacanthoma (KA development but is not sufficient for transformation and SCC development. We therefore propose that NF-κB activation in the absence of additional oncogenic events can promote TNF-dependent, actinic keratosis-like dysplasia and TNF-independent, KAs upon chemical carcinogensis. These studies suggest that resolution of KA cannot occur when NF-κB activation is constitutively enforced.

Novel 1,3,4-Oxadiazole Induces Anticancer Activity by Targeting NF-κB in Hepatocellular Carcinoma Cells

Directory of Open Access Journals (Sweden)

Chakrabhavi Dhananjaya Mohan

2018-03-01

Full Text Available Aberrant activation of NF-κB is linked with the progression of human malignancies including hepatocellular carcinoma (HCC, and blockade of NF-κB signaling could be a potential target in the treatment of several cancers. Therefore, designing of novel small molecule inhibitors that target NF-κB activation is of prime importance in the treatment of several cancers. In the present work, we report the synthesis of series of 1,3,4-oxadiazoles, investigated their anticancer potential against HCC cells, and identified 2-(3-chlorobenzo[b]thiophen-2-yl-5-(3-methoxyphenyl-1,3,4-oxadiazole (CMO as the lead compound. Further, we examined the effect of CMO on cell cycle distribution (flow cytometry, apoptosis (annexin V-propidium iodide-FITC staining, and phosphorylation of NF-κB signaling pathway proteins (IκB and p65 in HCC cells. We found that CMO induced antiproliferative effect in dose- and time-dependent manner. Also, CMO significantly increased the percentage of sub-G1 cell population and induced apoptosis. Furthermore, CMO found to decrease the phosphorylation of IκB (Ser 32 in the cytoplasmic extract and p65 (Ser 536 in the nuclear extract of HCC cells. It also abrogated the DNA binding ability and transcriptional activity of NF-κB. CMO induced the cleavage of PARP and caspase-3 in a time-dependent manner. In addition, transfection with p65 small interfering RNA blocks CMO-induced caspase-3/7 activation. Molecular docking analysis revealed that CMO interacts with the hydrophobic region of p65 protein. Thus, we are reporting CMO as an inhibitor of NF-κB signaling pathway.

MicroRNA-7/NF-κB signaling regulatory feedback circuit regulates gastric carcinogenesis

Science.gov (United States)

Zhao, Xiao-Di; Lu, Yuan-Yuan; Guo, Hao; Xie, Hua-Hong; He, Li-Jie; Shen, Gao-Fei; Zhou, Jin-Feng; Li, Ting; Hu, Si-Jun; Zhou, Lin; Han, Ya-Nan; Liang, Shu-Li; Wang, Xin; Wu, Kai-Chun; Shi, Yong-Quan; Nie, Yong-Zhan

2015-01-01

MicroRNAs play essential roles in gene expression regulation during carcinogenesis. Here, we investigated the role of miR-7 and the mechanism by which it is dysregulated in gastric cancer (GC). We used genome-wide screenings and identified RELA and FOS as novel targets of miR-7. Overexpression of miR-7 repressed RELA and FOS expression and prevented GC cell proliferation and tumorigenesis. These effects were clinically relevant, as low miR-7 expression was correlated with high RELA and FOS expression and poor survival in GC patients. Intriguingly, we found that miR-7 indirectly regulated RELA activation by targeting the IκB kinase IKKε. Furthermore, IKKε and RELA can repress miR-7 transcription, which forms a feedback circuit between miR-7 and nuclear factor κB (NF-κB) signaling. Additionally, we demonstrate that down-regulation of miR-7 may occur as a result of the aberrant activation of NF-κB signaling by Helicobacter pylori infection. These findings suggest that miR-7 may serve as an important regulator in GC development and progression. PMID:26261179

Molecular evidence for the existence of lipopolysaccharide-induced TNF-alpha factor (LITAF) and Rel/NF-kB pathways in disk abalone (Haliotis discus discus).

Science.gov (United States)

De Zoysa, Mahanama; Nikapitiya, Chamilani; Oh, Chulhong; Whang, Ilson; Lee, Jae-Seong; Jung, Sung-Ju; Choi, Cheol Young; Lee, Jehee

2010-01-01

The lipopolysaccharide-induced TNF-alpha factor (LITAF) and Rel family nuclear factor kappaB (Rel/NF-kB) are two important transcription factors which play major roles in the regulating inflammatory cytokine, apoptosis and immune related genes. Here, we report the discovery of disk abalone LITAF (AbLITAF) and Rel/NF-kB (AbRel/NF-kB) homologues and their immune responses. Full-length cDNA of AbLITAF consists of 441 bp open reading frame (ORF) that translates into putative peptide of 147 aa. Analysis of AbLITAF sequence showed it has characteristic LITAF (Zn(+2)) binding domain with two CXXC motifs. Phylogenetic analysis results further revealed that AbLITAF is a member of LITAF family. AbRel/NF-kB is 584 aa protein that contains several characteristic motifs including Rel homology domain (RHD), Rel protein signature, DNA binding motif, nuclear localization signal (NLS) and transcription factor immunoglobulin - like fold (TIG) similar to their invertebrate and vertebrate counterparts. Tissue specific analysis results showed that both AbLITAF and AbRel/NF-kB mRNA was expressed ubiquitously in all selected tissues in constitutive manner. However, constitutive expression of AbLITAF was higher than AbRel/NF-kB in all tissues except mantle. Upon immune challenge by bacteria (Vibrio alginolyticus, Vibrio parahemolyticus and Lysteria monocytogenes) and viral hemoragic septicemia virus (VHSV), AbLITAF showed the significant up-regulation in gills while AbRel/NF-kB transcription was not change significantly. Based on transcriptional response against immune challenge, we could suggest that regulation of TNF-alpha expression may have occurred mainly by LITAF activation rather than NF-kB in disk abalone. The cumulative data from other molluscs and our data with reference to TNF-alpha, LITAF and Rel/NF-kB from disk abalone provide strong evidence that LITAF and NF-kB are independent pathways likely to occur throughout the Phylum mollusca. 2010 Elsevier Ltd. All rights reserved.

Local and Systemic IKKε and NF-κB Signaling Associated with Sjögren’s Syndrome Immunopathogenesis

Directory of Open Access Journals (Sweden)

Weiqian Chen

2015-01-01

Full Text Available The activated NF-κB signaling pathway plays an important role in pathogenesis of primary Sjögren’s syndrome (pSS. The inhibitor of κB (IκB kinase (IKK family such as IKKα, IKKβ, IKKγ, and IKKε, is required for this signaling. Our aim was to investigate the role of IKKα/β/γ/ε in patients with untreated pSS. In minor salivary glands from pSS patients, phosphorylated IKKε (pIKKε, pIκBα, and pNF-κB p65 (p-p65 were highly expressed in ductal epithelium and infiltrating mononuclear cells by immunohistochemistry, compared to healthy individuals. pIKKα/β and pIKKγ were both negative. And pIKKε positively related to expression of p-p65. Furthermore, pIKKε and p-p65 expression significantly correlated with biopsy focus score and overall disease activity. Meanwhile, in peripheral blood mononuclear cells from pSS patients, pIKKε, total IKKε, pIKKα/β, and p-p65 were significantly increased by western blot, compared to healthy controls. However, there was no difference in IKKγ and IκBα between pSS patients and healthy individuals. These results demonstrated an abnormality of IKKε, IκBα, and NF-κB in pSS, suggesting a potential target of treatment for pSS based on the downregulation of IKKε expression and deregulation of NF-κB pathway.

Role of monoubiquitylation on the control of IκBα degradation and NF-κB activity.

Directory of Open Access Journals (Sweden)

Elisa Da Silva-Ferrada

Full Text Available The NF-κB pathway is regulated by multiple post-translational modifications including phosphorylation, ubiquitylation and SUMOylation. Many of these modifications act on the natural inhibitor IκBα modulating its capacity to control signal-mediated NF-κB activity. While the canonical pathway involving the phosphorylation and polyubiquitylation of IκBα has been well characterized, the role of these post-translational modifications in the control of basal NF-κB activity has not been deeply explored. Using the recently developed Tandem-repeated Ubiquitin Binding Entities (also known as ubiquitin traps to capture ubiquitylated proteins, we identified monoubiquitylated forms of IκBα from multiple rat organs and cell types. The identification of these forms was demonstrated through different procedures such as immunoprecipitations with specific ubiquitin antibodies or His6-Ubiquitin pull downs. Monoubiquitylated forms of IκBα are resistant to TNFα-mediated degradation and can be captured using TUBEs, even after proteasome inhibitors treatment. As it occurs for monoSUMOylation, monoubiquitylation is not dependent of the phosphorylation of IκBα on the serines 32/36 and is not optimally degraded after TNFα stimulation. A ubiquitin-IκBα fusion exhibits phosphorylation defects and resistance to TNFα mediated degradation similar to the ones observed for endogenous monoubiquitylated IκBα. The N-terminal attachment of a single ubiquitin moiety on the IκBα fusion results in a deficient binding to the IKKβ kinase and recruitment of the SCF ligase component βTrCP, promoting a negative impact on the NF-κB activity. Altogether, our results suggest the existence of a reservoir of monoubiquitylated IκBα resistant to TNFα-induced proteolysis, which is able to interact and repress DNA binding and NF-κB transcriptional activity. Such pool of IκBα may play an important role in the control of basal and signal-mediated NF-κB activity.

Ganoderma lucidum ethanol extract inhibits the inflammatory response by suppressing the NF-κB and toll-like receptor pathways in lipopolysaccharide-stimulated BV2 microglial cells.

Science.gov (United States)

Yoon, Hyun-Min; Jang, Kyung-Jun; Han, Min Seok; Jeong, Jin-Woo; Kim, Gi Young; Lee, Jai-Heon; Choi, Yung Hyun

2013-03-01

Ganoderma lucidum is a traditional Oriental medicine that has been widely used as a tonic to promote longevity and health in Korea and other Asian countries. Although a great deal of work has been carried out on the therapeutic potential of this mushroom, the pharmacological mechanisms of its anti-inflammatory actions remain unclear. In this study, we evaluated the inhibitory effects of G. lucidum ethanol extract (EGL) on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated murine BV2 microglia. We also investigated the effects of EGL on the LPS-induced activation of nuclear factor kappaB (NF-κB) and upregulation of toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). Elevated levels of nitric oxide (NO), prostaglandin E(2) (PGE(2)) and pro-inflammatory cytokine production were detected in BV2 microglia following LPS stimulation. We identifed that EGL significantly inhibits the excessive production of NO, PGE(2) and pro-inflammatory cytokines, including interleukin (IL)-1β and tumor necrosis factor-α in a concentration-dependent manner without causing cytotoxicity. In addition, EGL suppressed NF-κB translocation and transcriptional activity by blocking IκB degradation and inhibiting TLR4 and MyD88 expression in LPS-stimulated BV2 cells. Our results indicate that the inhibitory effects of EGL on LPS-stimulated inflammatory responses in BV2 microglia are associated with the suppression of the NF-κB and TLR signaling pathways. Therefore, EGL may be useful in the treatment of neurodegenerative diseases by inhibiting inflammatory mediator responses in activated microglia.

PUMA and NF-kB Are Cell Signaling Predictors of Reovirus Oncolysis of Breast Cancer.

Science.gov (United States)

Thirukkumaran, Chandini; Shi, Zhong-Qiao; Thirukkumaran, Ponnampalam; Luider, Joanne; Kopciuk, Karen; Spurrell, Jason; Elzinga, Kate; Morris, Don

2017-01-01

Reovirus is a ubiquitous RNA virus that exploits aberrant signaling pathways for its replication. The oncolytic potential of reovirus against numerous cancers under pre-clinical/clinical conditions has been documented by us and others. Despite its proven clinical activity, the underlying mechanisms of reovirus oncolysis is still not well elucidated. If reovirus therapy is to be optimized for cancer, including breast cancer patients, it is imperative to understand the mechanisms of reovirus oncolysis, especially in treatment of resistant tumour. In the present study global gene expression profiling was utilized as a preliminary roadmap to tease-out pivotal molecules involved in reovirus induced apoptosis in breast cancer. Reovirus treated HTB133 and MCF7 breast cancer cells revealed transcriptional alteration of a defined subset of apoptotic genes and members of the nuclear factor-kappa B (NF-kB) family and p53 upregulated modulator of apoptosis (PUMA) were prominent. Since NF-kB can paradoxically suppress or promote apoptosis in cancer, the significance of NF-kB in reovirus oncolysis of breast cancer was investigated. Real time PCR analysis indicated a 2.9-4.3 fold increase in NF-kB p65 message levels following reovirus infection of MCF7 and HTB133, respectively. Nuclear translocation of NF-kB p65 protein was also dramatically augmented post reovirus treatment and correlated with enhanced DNA binding. Pharmacologic inhibition of NF-kB lead to oncolytic protection and significant down regulation of PUMA message levels. PUMA down regulation using siRNA suppressed reovirus oncolysis via significantly repressed apoptosis in p53 mutant HTB133 cells. This study demonstrates for the first time that a prominent pathway of reovirus oncolysis of breast cancer is mediated through NF-kB and that PUMA upregulation is dependent on NF-kB activation. These findings represent potential therapeutic indicators of reovirus treatment in future clinical trials.

Andrographolide ameliorates OVA-induced lung injury in mice by suppressing ROS-mediated NF-κB signaling and NLRP3 inflammasome activation.

Science.gov (United States)

Peng, Shuang; Gao, Jian; Liu, Wen; Jiang, Chunhong; Yang, Xiaoling; Sun, Yang; Guo, Wenjie; Xu, Qiang

2016-12-06

In this study, we attempted to explore the effect and possible mechanism of Andrographolide on OVA-induced asthma. OVA challenge induced significant airway inflammatory cell recruitment and lung histological alterations, which were ameliorated by Andrographolide. The protein levels of cytokines in bron-choalveolar fluid (BALF) and serum were reduced by Andrographolide administration as well as the mRNA levels in lung tissue. Mechanically, Andrographolide markedly hampered the activation of nuclear factor-κB (NF-κB) and NLRP3 inflammasome both in vivo and vitro thus decreased levels of TNF-α and IL-1β. Finally, we confirmed that ROS scavenging was responsible for Andrographolide's inactivation of NF-κB and NLRP3 inflammasome signaling. Our study here revealed the effect and possible mechanism of Andrographolide on asthma, which may represent a new therapeutic approach for treating this disease.

The role of NF-κB signaling pathway in polyhexamethylene guanidine phosphate induced inflammatory response in mouse macrophage RAW264.7 cells.

Science.gov (United States)

Kim, Ha Ryong; Shin, Da Young; Chung, Kyu Hyuck

2015-03-04

Polyhexamethylene guanidine (PHMG) phosphate is a competitive disinfectant with strong antibacterial activity. However, epidemiologists revealed that inhaled PHMG-phosphate may increase the risk of pulmonary fibrosis associated with inflammation, resulting in the deaths of many people, including infants and pregnant women. In addition, in vitro and in vivo studies reported the inflammatory effects of PHMG-phosphate. Therefore, the aim of the present study was to clarify the inflammatory effects and its mechanism induced by PHMG-phosphate in murine RAW264.7 macrophages. Cell viability, inflammatory cytokine secretion, nuclear factor kappa B (NF-κB) activation, and reactive oxygen species (ROS) generation were investigated in macrophages exposed to PHMG-phosphate. PHMG-phosphate induced dose-dependent cytotoxicity, with LC50 values of 11.15-0.99mg/ml at 6 and 24h, respectively. PHMG-phosphate induced pro-inflammatory cytokines including IL-1β, IL-6, and IL-8. In particular, IL-8 expression was completely inhibited by the NF-κB inhibitor BAY11-7082. In addition, PHMG-phosphate decreased IκB-α protein expression and increased NF-κB-mediated luciferase activity, which was diminished by N-acetyl-l-cystein. However, abundant amounts of ROS were generated in the presence of PHMG-phosphate at high concentrations with a cytotoxic effect. Our results demonstrated that PHMG-phosphate triggered the activation of NF-κB signaling pathway by modulating the degradation of IκB-α. Furthermore, the NF-κB signaling pathway plays a critical role in the inflammatory responses induced by PHMG-phosphate. We assumed that ROS generated by PHMG-phosphate were associated with inflammatory responses as secondary mechanism. In conclusion, we suggest that PHMG-phosphate induces inflammatory responses via NF-κB signaling pathway. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Anti-Inflammatory Activity of Bee Venom in BV2 Microglial Cells: Mediation of MyD88-Dependent NF-κB Signaling Pathway.

Science.gov (United States)

Im, Eun Ju; Kim, Su Jung; Hong, Seung Bok; Park, Jin-Kyu; Rhee, Man Hee

2016-01-01

Bee venom has long been used as a traditional folk medicine in Korea. It has been reportedly used for the treatment of arthritis, cancer, and inflammation. Although its anti-inflammatory activity in lipopolysaccharide- (LPS-) stimulated inflammatory cells has been reported, the exact mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, the aim of this study was to investigate the anti-inflammatory mechanism of bee venom in BV2 microglial cells. We first investigated whether NO production in LPS-activated BV2 cells was inhibited by bee venom, and further iNOS mRNA and protein expressions were determined. The mRNA and protein levels of proinflammatory cytokines were examined using semiquantitative RT-PCR and immunoblotting, respectively. Moreover, modulation of the transcription factor NF-κB by bee venom was also investigated using a luciferase assay. LPS-induced NO production in BV2 microglial cells was significantly inhibited in a concentration-dependent manner upon pretreatment with bee venom. Bee venom markedly reduced the mRNA expression of COX-2, TNF-α, IL-1β, and IL-6 and suppressed LPS-induced activation of MyD88 and IRAK1 and phosphorylation of TAK1. Moreover, NF-κB translocation by IKKα/β phosphorylation and subsequent IκB-α degradation were also attenuated. Thus, collectively, these results indicate that bee venom exerts its anti-inflammatory activity via the IRAK1/TAK1/NF-κB signaling pathway.

Protective role of benfotiamine, a fat-soluble vitamin B1 analogue, in lipopolysaccharide-induced cytotoxic signals in murine macrophages.

Science.gov (United States)

Yadav, Umesh C S; Kalariya, Nilesh M; Srivastava, Satish K; Ramana, Kota V

2010-05-15

This study was designed to investigate the molecular mechanisms by which benfotiamine, a lipid-soluble analogue of vitamin B1, affects lipopolysaccharide (LPS)-induced inflammatory signals leading to cytotoxicity in the mouse macrophage cell line RAW264.7. Benfotiamine prevented LPS-induced apoptosis, expression of the Bcl-2 family of proapoptotic proteins, caspase-3 activation, and PARP cleavage and altered mitochondrial membrane potential and release of cytochrome c and apoptosis-inducing factor and phosphorylation and subsequent activation of p38-MAPK, stress-activated kinases (SAPK/JNK), protein kinase C, and cytoplasmic phospholipase A2 in RAW cells. Further, phosphorylation and degradation of inhibitory kappaB and consequent activation and nuclear translocation of the redox-sensitive transcription factor NF-kappaB were significantly prevented by benfotiamine. The LPS-induced increased expression of cytokines and chemokines and the inflammatory marker proteins iNOS and COX-2 and their metabolic products NO and PGE(2) was also blocked significantly. Thus, our results elucidate the molecular mechanism of the anti-inflammatory action of benfotiamine in LPS-induced inflammation in murine macrophages. Benfotiamine suppresses oxidative stress-induced NF-kappaB activation and prevents bacterial endotoxin-induced inflammation, indicating that vitamin B1 supplementation could be beneficial in the treatment of inflammatory diseases. Copyright 2010 Elsevier Inc. All rights reserved.

Fish oil suppresses cell growth and metastatic potential by regulating PTEN and NF-κB signaling in colorectal cancer.

Directory of Open Access Journals (Sweden)

Shevali Kansal

Full Text Available Homeostasis in eukaryotic tissues is tightly regulated by an intricate balance of the prosurvival and antisurvival signals. The tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10, a dual-specificity phosphatase, plays a functional role in cell cycle arrest and apoptosis. NF-κB and its downstream regulators (such as VEGF play a central role in prevention of apoptosis, promotion of inflammation and tumor growth. Therefore, we thought to estimate the expression of PTEN, Poly-ADP-ribose polymerase (PARP, NF-κBp50, NF-κBp65 and VEGF to evaluate the effect of supplementation of fish oil on apoptotic and inflammatory signaling in colon carcinoma. Male wistar rats in Group I received purified diet while Group II and III received modified diet supplemented with FO∶CO(1∶1&FO∶CO(2.5∶1 respectively. These were further subdivided into controls receiving ethylenediamine-tetra acetic-acid and treated groups received dimethylhydrazine-dihydrochloride (DMH/week for 4 weeks. Animals sacrificed 48 hours after last injection constituted initiation phase and that sacrificed after 16 weeks constituted post-initiation phase. We have analysed expression of PTEN, NF-κBp50, NF-κBp65 by flowcytometer and nuclear localization of NF-κB by immunofluorescence. PARP and VEGF were assessed by immunohistochemistry. In the initiation phase, animals receiving DMH have shown increased % of apoptotic cells, PTEN, PARP, NF-κBp50, NF-κBp65 and VEGF however in post-initiation phase no significant alteration in apoptosis with decreased PTEN and increased PARP, NF-κBp50, NF-κBp65 and VEGF were observed as compared to control animals. On treatment with both ratios of fish oil in both the phases, augmentation in % of apoptotic cells, decreased PTEN, PARP, NF-κBp50, NF-κBp65 and VEGF were documented with respect to DMH treated animals with effect being more exerted with higher ration in post-initiation phase. Hence, fish oil activates

WRI1-1, ABI5, NF-YA3 and NF-YC2 increase oil biosynthesis in coordination with hormonal signaling during fruit development in oil palm.

Science.gov (United States)

Yeap, Wan-Chin; Lee, Fong-Chin; Shabari Shan, Dilip Kumar; Musa, Hamidah; Appleton, David Ross; Kulaveerasingam, Harikrishna

2017-07-01

The oil biosynthesis pathway must be tightly controlled to maximize oil yield. Oil palm accumulates exceptionally high oil content in its mesocarp, suggesting the existence of a unique fruit-specific fatty acid metabolism transcriptional network. We report the complex fruit-specific network of transcription factors responsible for modulation of oil biosynthesis genes in oil palm mesocarp. Transcriptional activation of EgWRI1-1 encoding a key master regulator that activates expression of oil biosynthesis genes, is activated by three ABA-responsive transcription factors, EgNF-YA3, EgNF-YC2 and EgABI5. Overexpression of EgWRI1-1 and its activators in Arabidopsis accelerated flowering, increased seed size and oil content, and altered expression levels of oil biosynthesis genes. Protein-protein interaction experiments demonstrated that EgNF-YA3 interacts directly with EgWRI1-1, forming a transcription complex with EgNF-YC2 and EgABI5 to modulate transcription of oil biosynthesis pathway genes. Furthermore, EgABI5 acts downstream of EgWRKY40, a repressor that interacts with EgWRKY2 to inhibit the transcription of oil biosynthesis genes. We showed that expression of these activators and repressors in oil biosynthesis can be induced by phytohormones coordinating fruit development in oil palm. We propose a model highlighting a hormone signaling network coordinating fruit development and fatty acid biosynthesis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Ganoderma lucidum suppresses growth of breast cancer cells through the inhibition of Akt/NF-kappaB signaling.

Science.gov (United States)

Jiang, Jiahua; Slivova, Veronika; Harvey, Kevin; Valachovicova, Tatiana; Sliva, Daniel

2004-01-01

Ganoderma lucidum (Reishi, Lingzhi) is a popular Asian mushroom that has been used for more than 2 millennia for the general promotion of health and was therefore called the "Mushroom of Immortality." Ganoderma lucidum was also used in traditional Chinese medicine to prevent or treat a variety of diseases, including cancer. We previously demonstrated that Ganoderma lucidum suppresses the invasive behavior of breast cancer cells by inhibiting the transcription factor NF-kappaB. However, the molecular mechanisms responsible for the inhibitory effects of Ganoderma lucidum on the growth of highly invasive and metastatic breast cancer cells has not been fully elucidated. Here, we show that Ganoderma lucidum inhibits proliferation of breast cancer MDA-MB-231 cells by downregulating Akt/NF-kappaB signaling. Ganoderma lucidum suppresses phosphorylation of Akt on Ser473 and downregulates the expression of Akt, which results in the inhibition of NF-kappaB activity in MDA-MB-231 cells. The biological effect of Ganoderma lucidum was demonstrated by cell cycle arrest at G0/G1, which was the result of the downregulation of expression of NF-kappaB-regulated cyclin D1, followed by the inhibition of cdk4. Our results suggest that Ganoderma lucidum inhibits the growth of MDA-MB-231 breast cancer cells by modulating Akt/NF-kappaB signaling and could have potential therapeutic use for the treatment of breast cancer.

Effects of canonical NF-κB signaling pathway on the proliferation and odonto/osteogenic differentiation of human stem cells from apical papilla.

Science.gov (United States)

Li, Junjun; Yan, Ming; Wang, Zilu; Jing, Shuanglin; Li, Yao; Liu, Genxia; Yu, Jinhua; Fan, Zhipeng

2014-01-01

NF-κB signaling pathway plays a complicated role in the biological functions of mesenchymal stem cells. However, the effects of NF-κB pathway on the odonto/osteogenic differentiation of stem cells from apical papilla (SCAPs) remain unclear. The present study was designed to evaluate the effects of canonical NF-κB pathway on the osteo/odontogenic capacity of SCAPs in vitro. Western blot results demonstrated that NF-κB pathway in SCAPs was successfully activated by TNF-α or blocked by BMS-345541. NF-κB pathway-activated SCAPs presented a higher proliferation activity compared with control groups, as indicated by dimethyl-thiazol-diphenyl tetrazolium bromide assay (MTT) and flow cytometry assay (FCM). Wound scratch assay revealed that NF-κB pathway-activated SCAPs presented an improved migration capacity, enhanced alkaline phosphatase (ALP) activity, and upregulated mineralization capacity of SCAPs, as compared with control groups. Meanwhile, the odonto/osteogenic markers (ALP/ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, OPN/OPN, BSP/BSP, DSPP/DSP, and DMP-1/DMP-1) in NF-κB pathway-activated SCAPs were also significantly upregulated as compared with control groups at both protein and mRNA levels. However, NF-κB pathway-inhibited SCAPs exhibited a lower proliferation/migration capacity, and decreased odonto/osteogenic ability in comparison with control groups. Our findings suggest that classical NF-κB pathway plays a paramount role in the proliferation and committed differentiation of SCAPs.

Aspirin Prevention of Colorectal Cancer: Focus on NF-κB Signalling and the Nucleolus

Directory of Open Access Journals (Sweden)

Jingyu Chen

2017-07-01

Full Text Available Overwhelming evidence indicates that aspirin and related non-steroidal anti-inflammatory drugs (NSAIDs have anti-tumour activity and the potential to prevent cancer, particularly colorectal cancer. However, the mechanisms underlying this effect remain hypothetical. Dysregulation of the nuclear factor-kappaB (NF-κB transcription factor is a common event in many cancer types which contributes to tumour initiation and progression by driving expression of pro-proliferative/anti-apoptotic genes. In this review, we will focus on the current knowledge regarding NSAID effects on the NF-κB signalling pathway in pre-cancerous and cancerous lesions, and the evidence that these effects contribute to the anti-tumour activity of the agents. The nuclear organelle, the nucleolus, is emerging as a central regulator of transcription factor activity and cell growth and death. Nucleolar function is dysregulated in the majority of cancers which promotes cancer growth through direct and indirect mechanisms. Hence, this organelle is emerging as a promising target for novel therapeutic agents. Here, we will also discuss evidence for crosstalk between the NF-κB pathway and nucleoli, the role that this cross-talk has in the anti-tumour effects of NSAIDs and ways forward to exploit this crosstalk for therapeutic purpose.

Pentacyclic Triterpenoids Inhibit IKKβ Mediated Activation of NF-κB Pathway: In Silico and In Vitro Evidences.

Directory of Open Access Journals (Sweden)

Kalpesh R Patil

Full Text Available Pentacyclic Triterpenoids (PTs and their analogues as well as derivatives are emerging as important drug leads for various diseases. They act through a variety of mechanisms and a majority of them inhibit the nuclear factor kappa-beta (NF-κB signaling pathway. In this study, we examined the effects of the naturally occurring PTs on IκB kinase-β (IKKβ, which has great scientific relevance in the NF-κB signaling pathway. On virtual screening, 109 PTs were screened through the PASS (prediction of activity spectra of substances software for prediction of NF-κB inhibitory activity followed by docking on the NEMO/IKKβ association complex (PDB: 3BRV and testing for compliance with the softened Lipinski's Rule of Five using Schrodinger (LLC, New York, USA. Out of the projected 45 druggable PTs, Corosolic Acid (CA, Asiatic Acid (AA and Ursolic Acid (UA were assayed for IKKβ kinase activity in the cell free medium. The UA exhibited a potent IKKβ inhibitory effect on the hotspot kinase assay with IC50 of 69 μM. Whereas, CA at 50 μM concentration markedly reduced the NF-κB luciferase activity and phospho-IKKβ protein expressions. The PTs tested, attenuated the expression of the NF-κB cascade proteins in the LPS-stimulated RAW 264.7 cells, prevented the phosphorylation of the IKKα/β and blocked the activation of the Interferon-gamma (IFN-γ. The results suggest that the IKKβ inhibition is the major mechanism of the PTs-induced NF-κB inhibition. PASS predictions along with in-silico docking against the NEMO/IKKβ can be successfully applied in the selection of the prospective NF-κB inhibitory downregulators of IKKβ phosphorylation.

Styrene induces an inflammatory response in human lung epithelial cells via oxidative stress and NF-κB activation

International Nuclear Information System (INIS)

Roeder-Stolinski, Carmen; Fischaeder, Gundula; Oostingh, Gertie Janneke; Feltens, Ralph; Kohse, Franziska; Bergen, Martin von; Moerbt, Nora; Eder, Klaus; Duschl, Albert; Lehmann, Irina

2008-01-01

Styrene is a volatile organic compound (VOC) that is widely used as a solvent in many industrial settings. Chronic exposure to styrene can result in irritation of the mucosa of the upper respiratory tract. Contact of styrene with epithelial cells stimulates the expression of a variety of inflammatory mediators, including the chemotactic cytokine monocyte chemoattractant protein-1 (MCP-1). To characterise the underlying mechanisms of the induction of inflammatory signals by styrene, we investigated the influence of this compound on the induction of oxidative stress and the activation of the nuclear factor-kappa B (NF-κB) signalling pathway in human lung epithelial cells (A549). The results demonstrate that styrene-induced MCP-1 expression, as well as the expression of the oxidative stress marker glutathione S-transferase (GST), is associated with a concentration dependent pattern of NF-κB activity. An inhibitor of NF-κB, IKK-NBD, and the anti-inflammatory antioxidant N-acetylcysteine (NAC) were both effective in suppressing styrene-induced MCP-1 secretion. In addition, NAC was capable of inhibiting the upregulation of GST expression. Our findings suggest that the activation of the NF-κB signalling pathway by styrene is mediated via a redox-sensitive mechanism

Curcumin Modulates the Radiosensitivity of Colorectal Cancer Cells by Suppressing Constitutive and Inducible NF-κB Activity

International Nuclear Information System (INIS)

Sandur, Santosh K.; Deorukhkar, Amit; Pandey, Manoj K.; Pabon, Ana Maria B.S.; Shentu, Shujun; Guha, Sushovan; Aggarwal, Bharat B.; Krishnan, Sunil

2009-01-01

Purpose: Radiation therapy is an integral part of the preoperative treatment of rectal cancers. However, only a minority of patients achieve a complete pathologic response to therapy because of resistance of these tumors to radiation therapy. This resistance may be mediated by constitutively active pro-survival signaling pathways or by inducible/acquired mechanisms in response to radiation therapy. Simultaneous inhibition of these pathways can sensitize these tumors to radiation therapy. Methods and Materials: Human colorectal cancer cells were exposed to clinically relevant doses of gamma rays, and the mechanism of their radioresistance was investigated. We characterized the transcription factor nuclear factor-κB (NF-κB) activation as a mechanism of inducible radioresistance in colorectal cancer and used curcumin, the active ingredient in the yellow spice turmeric, to overcome this resistance. Results: Curcumin inhibited the proliferation and the post-irradiation clonogenic survival of multiple colorectal cancer cell lines. Radiation stimulated NF-κB activity in a dose- and time-dependent manner, whereas curcumin suppressed this radiation-induced NF-κB activation via inhibition of radiation-induced phosphorylation and degradation of inhibitor of κB alpha, inhibition of inhibitor of κB kinase activity, and inhibition of Akt phosphorylation. Curcumin also suppressed NF-κB-regulated gene products (Bcl-2, Bcl-x L , inhibitor of apoptosis protein-2, cyclooxygenase-2, and cyclin D1). Conclusions: Our results suggest that transient inducible NF-κB activation provides a prosurvival response to radiation that may account for development of radioresistance. Curcumin blocks this signaling pathway and potentiates the antitumor effects of radiation therapy.

NF-κB activity in muscle from obese and type 2 diabetic subjects under basal and exercise-stimulated conditions.

Science.gov (United States)

Tantiwong, Puntip; Shanmugasundaram, Karthigayan; Monroy, Adriana; Ghosh, Sangeeta; Li, Mengyao; DeFronzo, Ralph A; Cersosimo, Eugenio; Sriwijitkamol, Apiradee; Mohan, Sumathy; Musi, Nicolas

2010-11-01

NF-κB is a transcription factor that controls the gene expression of several proinflammatory proteins. Cell culture and animal studies have implicated increased NF-κB activity in the pathogenesis of insulin resistance and muscle atrophy. However, it is unclear whether insulin-resistant human subjects have abnormal NF-κB activity in muscle. The effect that exercise has on NF-κB activity/signaling also is not clear. We measured NF-κB DNA-binding activity and the mRNA level of putative NF-κB-regulated myokines interleukin (IL)-6 and monocyte chemotactic protein-1 (MCP-1) in muscle samples from T2DM, obese, and lean subjects immediately before, during (40 min), and after (210 min) a bout of moderate-intensity cycle exercise. At baseline, NF-κB activity was elevated 2.1- and 2.7-fold in obese nondiabetic and T2DM subjects, respectively. NF-κB activity was increased significantly at 210 min following exercise in lean (1.9-fold) and obese (2.6-fold) subjects, but NF-κB activity did not change in T2DM. Exercise increased MCP-1 mRNA levels significantly in the three groups, whereas IL-6 gene expression increased significantly only in lean and obese subjects. MCP-1 and IL-6 gene expression peaked at the 40-min exercise time point. We conclude that insulin-resistant subjects have increased basal NF-κB activity in muscle. Acute exercise stimulates NF-κB in muscle from nondiabetic subjects. In T2DM subjects, exercise had no effect on NF-κB activity, which could be explained by the already elevated NF-κB activity at baseline. Exercise-induced MCP-1 and IL-6 gene expression precedes increases in NF-κB activity, suggesting that other factors promote gene expression of these cytokines during exercise.

Andrographolide suppresses proliferation of human colon cancer SW620 cells through the TLR4/NF-κB/MMP-9 signaling pathway.

Science.gov (United States)

Zhang, Rui; Zhao, Jian; Xu, Jian; Jiao, De-Xin; Wang, Jian; Gong, Zhi-Qiang; Jia, Jian-Hui

2017-10-01

Modern pharmacological research has revealed that andrographolide has various functions, including anti-bacterial, anti-inflammatory and anti-viral effects, immunoregulation, treating cardiovascular and cerebrovascular diseases, and prevention and treatment of alcoholic liver injury. The present study investigated whether andrographolide suppresses the proliferation of human colon cancer cell through the Toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB/matrix metalloproteinase-9 (MMP-9) signaling pathway. The MTT assay and lactate dehydrogenase assay were used to evaluate the anticancer effects of andrographolide on cell proliferation and cytotoxicity in human colon cancer SW620 cells. Flow cytometry was used to analyze the anticancer effects of andrographolide on apoptosis by Annexin V-fluorescein isothiocyanate/propidium iodide kit. The effects of andrographolide on the activity of caspase-3/9 were measured using ELISA. Western blot analysis was also used to analyze the protein expression of TLR4, myeloid differentiation primary response gene 88 (MyD88), NF-κB-p65 and MMP-9. In the present study, it was found that andrographolide suppressed the cell proliferation, augmented cytotoxicity, evoked cell apoptosis and activated caspase-3/9 activities in human colon cancer SW620 cells. The results revealed that the anti-proliferation effects of andrographolide on the SW620 cells was associated with the inhibition of TLR4, MyD88, NF-κB-p65 and MMP-9 signaling activation. The results suggest that andrographolide is a promising drug for treatment of human colon cancer via suppression of the TLR4/NF-κB/MMP-9 signaling pathway.

Endocytosis-independent function of clathrin heavy chain in the control of basal NF-κB activation.

Directory of Open Access Journals (Sweden)

Man Lyang Kim

Full Text Available BACKGROUND: Nuclear factor-κB (NF-κB is a transcription factor that regulates the transcription of genes involved in a variety of biological processes, including innate and adaptive immunity, stress responses and cell proliferation. Constitutive or excessive NF-κB activity has been associated with inflammatory disorders and higher risk of cancer. In contrast to the mechanisms controlling inducible activation, the regulation of basal NF-κB activation is not well understood. Here we test whether clathrin heavy chain (CHC contributes to the regulation of basal NF-κB activity in epithelial cells. METHODOLOGY: Using RNA interference to reduce endogenous CHC expression, we found that CHC is required to prevent constitutive activation of NF-κB and gene expression. Immunofluorescence staining showed constitutive nuclear localization of the NF-κB subunit p65 in absence of stimulation after CHC knockdown. Elevated basal p65 nuclear localization is caused by constitutive phosphorylation and degradation of inhibitor of NF-κB alpha (IκBα through an IκB kinase α (IKKα-dependent mechanism. The role of CHC in NF-κB signaling is functionally relevant as constitutive expression of the proinflammatory chemokine interleukin-8 (IL-8, whose expression is regulated by NF-κB, was found after CHC knockdown. Disruption of clathrin-mediated endocytosis by chemical inhibition or depletion of the μ2-subunit of the endocytosis adaptor protein AP-2, and knockdown of clathrin light chain a (CHLa, failed to induce constitutive NF-κB activation and IL-8 expression, showing that CHC acts on NF-κB independently of endocytosis and CLCa. CONCLUSIONS: We conclude that CHC functions as a built-in molecular brake that ensures a tight control of basal NF-κB activation and gene expression in unstimulated cells. Furthermore, our data suggest a potential link between a defect in CHC expression and chronic inflammation disorder and cancer.

OSU-A9 inhibits angiogenesis in human umbilical vein endothelial cells via disrupting Akt–NF-κB and MAPK signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Omar, Hany A. [Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210 (United States); Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Arafa, El-Shaimaa A. [Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Salama, Samir A. [Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11511 (Egypt); Arab, Hany H. [Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo 11562 (Egypt); Wu, Chieh-Hsi, E-mail: chhswu@mail.cmu.edu.tw [School of Pharmacy, China Medical University, Taichung 40402, Taiwan (China); Weng, Jing-Ru, E-mail: columnster@gmail.com [Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan (China)

2013-11-01

Since the introduction of angiogenesis as a useful target for cancer therapy, few agents have been approved for clinical use due to the rapid development of resistance. This problem can be minimized by simultaneous targeting of multiple angiogenesis signaling pathways, a potential strategy in cancer management known as polypharmacology. The current study aimed at exploring the anti-angiogenic activity of OSU-A9, an indole-3-carbinol-derived pleotropic agent that targets mainly Akt–nuclear factor-kappa B (NF-κB) signaling which regulates many key players of angiogenesis such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Human umbilical vein endothelial cells (HUVECs) were used to study the in vitro anti-angiogenic effect of OSU-A9 on several key steps of angiogenesis. Results showed that OSU-A9 effectively inhibited cell proliferation and induced apoptosis and cell cycle arrest in HUVECs. Besides, OSU-A9 inhibited angiogenesis as evidenced by abrogation of migration/invasion and Matrigel tube formation in HUVECs and attenuation of the in vivo neovascularization in the chicken chorioallantoic membrane assay. Mechanistically, Western blot, RT-PCR and ELISA analyses showed the ability of OSU-A9 to inhibit MMP-2 production and VEGF expression induced by hypoxia or phorbol-12-myristyl-13-acetate. Furthermore, dual inhibition of Akt–NF-κB and mitogen-activated protein kinase (MAPK) signaling, the key regulators of angiogenesis, was observed. Together, the current study highlights evidences for the promising anti-angiogenic activity of OSU-A9, at least in part through the inhibition of Akt–NF-κB and MAPK signaling and their consequent inhibition of VEGF and MMP-2. These findings support OSU-A9's clinical promise as a component of anticancer therapy. - Highlights: • The antiangiogenic activity of OSU-A9 in HUVECs was explored. • OSU-A9 inhibited HUVECs proliferation, migration, invasion and tube formation. • OSU-A9

Modeling oscillatory control in NF-¿B, p53 and Wnt signaling

DEFF Research Database (Denmark)

Mengel, Benedicte; Hunziker, Alexander; Pedersen, Lykke

2010-01-01

Oscillations are commonly observed in cellular behavior and span a wide range of timescales, from seconds in calcium signaling to 24 hours in circadian rhythms. In between lie oscillations with time periods of 1-5 hours seen in NF-¿B, p53 and Wnt signaling, which play key roles in the immune system......, cell growth/death and embryo development, respectively. In the first part of this article, we provide a brief overview of simple deterministic models of oscillations. In particular, we explain the mechanism of saturated degradation that has been used to model oscillations in the NF-¿B, p53 and Wnt...

Proinflammatory cytokine tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) suppresses satellite cell self-renewal through inversely modulating Notch and NF-κB signaling pathways.

Science.gov (United States)

Ogura, Yuji; Mishra, Vivek; Hindi, Sajedah M; Kuang, Shihuan; Kumar, Ashok

2013-12-06

Satellite cell self-renewal is an essential process to maintaining the robustness of skeletal muscle regenerative capacity. However, extrinsic factors that regulate self-renewal of satellite cells are not well understood. Here, we demonstrate that TWEAK cytokine reduces the proportion of Pax7(+)/MyoD(-) cells (an index of self-renewal) on myofiber explants and represses multiple components of Notch signaling in satellite cell cultures. The number of Pax7(+) cells is significantly increased in skeletal muscle of TWEAK knock-out (KO) mice compared with wild-type in response to injury. Furthermore, Notch signaling is significantly elevated in cultured satellite cells and in regenerating myofibers of TWEAK-KO mice. Forced activation of Notch signaling through overexpression of the Notch1 intracellular domain (N1ICD) rescued the TWEAK-mediated inhibition of satellite cell self-renewal. TWEAK also activates the NF-κB transcription factor in satellite cells and inhibition of NF-κB significantly improved the number of Pax7(+) cells in TWEAK-treated cultures. Furthermore, our results demonstrate that a reciprocal interaction between NF-κB and Notch signaling governs the inhibitory effect of TWEAK on satellite cell self-renewal. Collectively, our study demonstrates that TWEAK suppresses satellite cell self-renewal through activating NF-κB and repressing Notch signaling.

Ceftiofur impairs pro-inflammatory cytokine secretion through the inhibition of the activation of NF-κB and MAPK

International Nuclear Information System (INIS)

Ci Xinxin; Song Yu; Zeng Fanqin; Zhang Xuemei; Li Hongyu; Wang Xinrui; Cui Junqing; Deng Xuming

2008-01-01

Ceftiofur is a new broad-spectrum, third-generation cephalosporin antibiotic for veterinary use. Immunopharmacological studies can provide new information on the immunomodulatory activities of some drugs, including their effect on cytokine productions. For this reason, we investigated the effect of ceftiofur on cytokine productions in vitro. We found that ceftiofur can downregulate tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), but did not affect interleukin-10 (IL-10) production. We further investigated signal transduction mechanisms to determine how ceftiofur affects. RAW 264.7 cells were pretreated with 1, 5, or 10 mg/L of ceftiofur 1 h prior to treatment with 1 mg/L of LPS. Thirty minutes later, cells were harvested and mitogen activated protein kinases (MAPKs) activation was measured by Western blot. Alternatively, cells were fixed and nuclear factor-κB (NF-κB) activation was measured using immunocytochemical analysis. Signal transduction studies showed that ceftiofur significantly inhibited extracellular signal-regulated kinase (ERK), p38, and c-jun NH 2 -terminal kinase (JNK) phosphorylation protein expression. Ceftiofur also inhibited p65-NF-κB translocation into the nucleus. Therefore, ceftiofur may inhibit LPS-induced production of inflammatory cytokines by blocking NF-κB and MAPKs signaling in RAW264.7 cells

Deleterious effect of salusin-β in paraventricular nucleus on sympathetic activity and blood pressure via NF-κB signaling in a rat model of obesity hypertension.

Science.gov (United States)

Huang, Xiaodong; Wang, Yanchun; Ren, Kuang

2015-08-01

The paraventricular nucleus (PVN) has been shown to play a critical role in regulating blood pressure and sympathetic activity in obesity hypertension (OH). Salusin-β is a bioactive peptide with potential roles in mediating cardiovascular activity. The study was designed to test the hypothesis that salusin-β in the PVN can modulate sympathetic activity and blood pressure in OH. Male Sprague-Dawley rats were used to induce OH by a 12-week feeding of a high-fat diet (42% kcal as fat). Microinjection of salusin-β into the PVN increased the renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) in a dose-dependent manner, whereas salusin-β antibody elicited significant decreases in RSNA, MAP and HR, and abolished the effects of salusin-β only in the OH rats. As expected, the OH rats had a higher norepinephrine level, which was further increased by salusin-β. Furthermore, salusin-β in the PVN accelerated the nuclear translocation of the p65 subunit of nuclear factor kappa B (NF-KB) and the degradation of IKB-α (an endogenous inhibitor of NF-KB). Pretreatment with pyrrolidine dithiocarbamate (an exogenous inhibitor of NF-KB) decreased RSNA, MAP and HR, and abolished the effects of salusin-β in the PVN in the OH rats. We concluded that salusin-β in the PVN markedly increased sympathetic outflow and blood pressure in diet-induced OH rats via NF-κB signaling.

DMAV in Drinking Water Activated NF-κB Signal Pathway and Increased TGF-β and IL-1β Expressions in Bladder Epithelial Cells of Rats

Directory of Open Access Journals (Sweden)

Siqi Cao

2015-01-01

Full Text Available Dimethylarsinic acid (DMAV is the main product of arsenic methylation metabolism in vivo and is rat bladder carcinogen and tumor promoting agent. In this study, we measured the expressions of mRNA and proteins of NF-κB pathway members, IKKα, IKKβ, p65, and p50 in rat bladder epithelium by qRT-PCR and immunohistochemical analysis after rats received drinking water containing 100 and 200 ppm DMAV for 10 weeks. Transforming growth factor-β (TGF-β immunoexpression in rat bladder epithelium and urine level of IL-1β also were determined. We found that DMAV dramatically increased the mRNA levels of NF-κB p50 and IKKα in the bladder epithelium of rats compared to the control group. Immunohistochemical examinations showed that DMAV increased immunoreactivities of IKKα, IKKβ, and phospho-NF-κB p50 in the cytoplasm and phospho-NF-κB p50 and p65 in nucleus of rat urothelial cells. In addition, DMAV treated rats exhibited significantly increased inflammatory factor TGF-β immunoreactivity in bladder epithelium and IL-1β secretion in urine. These data suggest that DMAV could activate NF-κB signal pathway and increase TGF-β and IL-1β expressions in bladder epithelial cells of rats.

Bmi-1-targeting suppresses osteosarcoma aggressiveness through the NF-κB signaling pathway

Science.gov (United States)

Liu, Jiaguo; Luo, Bin; Zhao, Meng

2017-01-01

Bone cancer is one of the most lethal malignancies and the specific causes of tumor initiation are not well understood. B-cell-specific Moloney murine leukemia virus integration site 1 protein (Bmi-1) has been reported to be associated with the initiation and progression of osteosarcoma, and as a prognostic indicator in the clinic. In the current study, a full-length antibody targeting Bmi-1 (AbBmi-1) was produced and the preclinical value of Bmi-1-targeted therapy was evaluated in bone carcinoma cells and tumor xenograft mice. The results indicated that the Bmi-1 expression level was markedly upregulated in bone cancer cell lines, and inhibition of Bmi-1 by AbBmi-1 reduced the invasiveness and migration of osteosarcoma cells. Overexpression of Bmi-1 promoted proliferation and angiogenesis, and increased apoptosis resistance induced by cisplatin via the nuclear factor-κB (NF-κB) signal pathway. In addition, AbBmi-1 treatment inhibited the tumorigenicity of osteosarcoma cells in vivo. Furthermore, AbBmi-1 blocked NF-κB signaling and reduced MMP-9 expression. Furthermore, Bmi-1 promoted osteosarcoma tumor growth, whereas AbBmi-1 significantly inhibited osteosarcoma tumor growth in vitro and in vivo. Notably, AbBmi-1 decreased the percentages of Ki67-positive cells and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells in tumors compared with Bmi-1-treated and PBS controls. Notably, MMP-9 and NF-κB expression were downregulated by treatment with AbBmi-1 in MG-63 osteosarcoma cells. In conclusion, the data provides evidence that AbBmi-1 inhibited the progression of osteosarcoma, suggesting that AbBmi-1 may be a novel anti-cancer agent through the inhibition of Bmi-1 via activating the NF-κB pathway in osteosarcoma. PMID:28983587

Interactions among oscillatory pathways in NF-kappa B signaling

Directory of Open Access Journals (Sweden)

White Michael RH

2011-02-01

Full Text Available Abstract Background Sustained stimulation with tumour necrosis factor alpha (TNF-alpha induces substantial oscillations—observed at both the single cell and population levels—in the nuclear factor kappa B (NF-kappa B system. Although the mechanism has not yet been elucidated fully, a core system has been identified consisting of a negative feedback loop involving NF-kappa B (RelA:p50 hetero-dimer and its inhibitor I-kappa B-alpha. Many authors have suggested that this core oscillator should couple to other oscillatory pathways. Results First we analyse single-cell data from experiments in which the NF-kappa B system is forced by short trains of strong pulses of TNF-alpha. Power spectra of the ratio of nuclear-to-cytoplasmic concentration of NF-kappa B suggest that the cells' responses are entrained by the pulsing frequency. Using a recent model of the NF-kappa B system due to Caroline Horton, we carried out extensive numerical simulations to analyze the response frequencies induced by trains of pulses of TNF-alpha stimulation having a wide range of frequencies and amplitudes. These studies suggest that for sufficiently weak stimulation, various nonlinear resonances should be observable. To explore further the possibility of probing alternative feedback mechanisms, we also coupled the model to sinusoidal signals with a wide range of strengths and frequencies. Our results show that, at least in simulation, frequencies other than those of the forcing and the main NF-kappa B oscillator can be excited via sub- and superharmonic resonance, producing quasiperiodic and even chaotic dynamics. Conclusions Our numerical results suggest that the entrainment phenomena observed in pulse-stimulated experiments is a consequence of the high intensity of the stimulation. Computational studies based on current models suggest that resonant interactions between periodic pulsatile forcing and the system's natural frequencies may become evident for sufficiently

Vorinostat, a HDAC inhibitor, showed anti-osteoarthritic activities through inhibition of iNOS and MMP expression, p38 and ERK phosphorylation and blocking NF-κB nuclear translocation.

Science.gov (United States)

Zhong, Hui-ming; Ding, Qian-hai; Chen, Wei-ping; Luo, Ru-bin

2013-10-01

Overproduction of nitric oxide (NO) and matrix metalloproteinases (MMPs) plays an important role in the pathogenesis of osteoarthritis (OA). In present study, we investigated whether vorinostat can inhibit the catabolic effects of IL-1β in vitro, especially the inhibition of MMPs and inducible nitric oxide synthase (iNOS) through the attenuation of nuclear factor kappa-B (NF-κB) and mitogen activated protein kinase (MAPK) pathways in human chondrocytes. Human OA chondrocytes were either left untreated or treated with various concentrations of vorinostat followed by incubation with IL-1β (5ng/mL). Effects of vorinostat on IL-1β-induced gene and protein expression of iNOS, MMP-1, MMP-13 and tissue inhibitors of metalloproteinase-1 (TIMP-1) were verified by quantitative real time-PCR and Western blot analysis. Production of NO, MMP-1, MMP-13 and TIMP-1 released in culture supernatant was estimated using commercially available kits. The roles of NF-κB and MAPK pathways in the regulation of targeted genes and the mechanism involved in vorinostat mediated modulation of these genes were determined by Western blot using specific antibodies. We found that vorinostat down-regulated iNOS, MMP-1 and MMP-13 expression and up-regulated TIMP-1 expression in human OA chondrocytes. In addition, the release of NO, MMP-1 and MMP-13 secreted from IL-1β stimulated chondrocytes was also suppressed by vorinostat. Interestingly, vorinostat selectively inhibited IL-1β-induced p38 and ERK1/2 activation without affecting JNK activation. Furthermore, we observed that vorinostat inhibited NF-κB pathway by suppressing the degradation of I-κBα and attenuating NF-κB p65 translocation to the nucleus. These results suggest that vorinostat may be a promising therapeutic agent for the prevention and treatment of OA. © 2013.

Fungal-induced cell cycle impairment, chromosome instability and apoptosis via differential activation of NF-κB.

Directory of Open Access Journals (Sweden)

Mariem Ben-Abdallah

Full Text Available Microbial pathogens have developed efficient strategies to compromise host immune responses. Cryptococcus neoformans is a facultative intracellular pathogen, recognised as the most common cause of systemic fungal infections leading to severe meningoencephalitis, mainly in immunocompromised patients. This yeast is characterized by a polysaccharide capsule, which inhibits its phagocytosis. Whereas phagocytosis escape and macrophage intracellular survival have been intensively studied, extracellular survival of this yeast and restraint of host innate immune response are still poorly understood. In this study, we have investigated whether C. neoformans affected macrophage cell viability and whether NF-κB (nuclear factor-κB, a key regulator of cell growth, apoptosis and inflammation, was involved. Using wild-type (WT as well as mutant strains of C. neoformans for the pathogen side, and WT and mutant cell lines with altered NF-κB activity or signalling as well as primary macrophages for the host side, we show that C. neoformans manipulated NF-κB-mediated signalling in a unique way to regulate macrophage cell fate and viability. On the one hand, serotype A strains reduced macrophage proliferation in a capsule-independent fashion. This growth decrease, which required a critical dosage of NF-κB activity, was caused by cell cycle disruption and aneuploidy, relying on fungal-induced modification of expression of several cell cycle checkpoint regulators in S and G2/M phases. On the other hand, C. neoformans infection induced macrophage apoptosis in a capsule-dependent manner with a differential requirement of the classical and alternative NF-κB signalling pathways, the latter one being essential. Together, these findings shed new light on fungal strategies to subvert host response through uncoupling of NF-κB activity in pathogen-controlled apoptosis and impairment of cell cycle progression. They also provide the first demonstration of induction of

A new structural class of proteasome inhibitors that prevent NF-kappa B activation.

Science.gov (United States)

Lum, R T; Kerwar, S S; Meyer, S M; Nelson, M G; Schow, S R; Shiffman, D; Wick, M M; Joly, A

1998-05-01

The multicatalytic proteinase or proteasome is a highly conserved cellular structure that is responsible for the ATP-dependent proteolysis of many proteins involved in important regulatory cellular processes. We have identified a novel class of inhibitors of the chymotrypsin-like proteolytic activity of the 20S proteasome that exhibit IC50 values ranging from 0.1 to 0.5 microgram/mL (0.1 to 1 microM). In cell proliferation assays, these compounds inhibit growth with an IC50 ranging from 5 to 10 micrograms/mL (10-20 microM). A representative member of this class of inhibitors was tested in other biological assays. CVT-634 (5-methoxy-1-indanone-3-acetyl-leu-D-leu-1-indanylamide) prevented lipopolysaccharide (LPS), tumor necrosis factor (TNF)-, and phorbol ester-induced activation of nuclear factor kappa B (NF-kappa B) in vitro by preventing signal-induced degradation of I kappa B-alpha. In these studies, the I kappa B-alpha that accumulated was hyperphosphorylated, indicating that CVT-634 did not inhibit I kappa B-alpha kinase, the enzyme responsible for signal-induced phosphorylation of I kappa B-alpha. In vivo studies indicated that CVT-634 prevented LPS-induced TNF synthesis in a murine macrophage cell line. In addition, in mice pretreated with CVT-634 at 25 and 50 mg/kg and subsequently treated with LPS, serum TNF levels were significantly lower (225 +/- 59 and 83 +/- 41 pg/mL, respectively) than in those mice that were treated only with LPS (865 +/- 282 pg/mL). These studies suggest that specific inhibition of the chymotrypsin-like activity of the proteasome is sufficient to prevent signal-induced NF-kappa B activation and that the proteasome is a novel target for the identification of agents that may be useful in the treatment of diseases whose etiology is dependent upon the activation of NF-kappa B.

Antioxidant Activity of γ-Oryzanol: A Complex Network of Interactions

Directory of Open Access Journals (Sweden)

Igor Otavio Minatel

2016-08-01

Full Text Available γ-oryzanol (Orz, a steryl ferulate extracted from rice bran layer, exerts a wide spectrum of biological activities. In addition to its antioxidant activity, Orz is often associated with cholesterol-lowering, anti-inflammatory, anti-cancer and anti-diabetic effects. In recent years, the usefulness of Orz has been studied for the treatment of metabolic diseases, as it acts to ameliorate insulin activity, cholesterol metabolism, and associated chronic inflammation. Previous studies have shown the direct action of Orz when downregulating the expression of genes that encode proteins related to adiposity (CCAAT/enhancer binding proteins (C/EBPs, inflammatory responses (nuclear factor kappa-B (NF-κB, and metabolic syndrome (peroxisome proliferator-activated receptors (PPARs. It is likely that this wide range of beneficial activities results from a complex network of interactions and signals triggered, and/or inhibited by its antioxidant properties. This review focuses on the significance of Orz in metabolic disorders, which feature remarkable oxidative imbalance, such as impaired glucose metabolism, obesity, and inflammation.

Antioxidant Activity of γ-Oryzanol: A Complex Network of Interactions.

Science.gov (United States)

Minatel, Igor Otavio; Francisqueti, Fabiane Valentini; Corrêa, Camila Renata; Lima, Giuseppina Pace Pereira

2016-08-09

γ-oryzanol (Orz), a steryl ferulate extracted from rice bran layer, exerts a wide spectrum of biological activities. In addition to its antioxidant activity, Orz is often associated with cholesterol-lowering, anti-inflammatory, anti-cancer and anti-diabetic effects. In recent years, the usefulness of Orz has been studied for the treatment of metabolic diseases, as it acts to ameliorate insulin activity, cholesterol metabolism, and associated chronic inflammation. Previous studies have shown the direct action of Orz when downregulating the expression of genes that encode proteins related to adiposity (CCAAT/enhancer binding proteins (C/EBPs)), inflammatory responses (nuclear factor kappa-B (NF-κB)), and metabolic syndrome (peroxisome proliferator-activated receptors (PPARs)). It is likely that this wide range of beneficial activities results from a complex network of interactions and signals triggered, and/or inhibited by its antioxidant properties. This review focuses on the significance of Orz in metabolic disorders, which feature remarkable oxidative imbalance, such as impaired glucose metabolism, obesity, and inflammation.

NF-kappaB and p53 are the dominant apoptosis-inducing transcription factors elicited by the HIV-1 envelope.

Science.gov (United States)

Perfettini, Jean-Luc; Roumier, Thomas; Castedo, Maria; Larochette, Nathanael; Boya, Patricia; Raynal, Brigitte; Lazar, Vladimir; Ciccosanti, Fabiola; Nardacci, Roberta; Penninger, Josef; Piacentini, Mauro; Kroemer, Guido

2004-03-01

The coculture of cells expressing the HIV-1 envelope glycoprotein complex (Env) with cells expressing CD4 results into cell fusion, deregulated mitosis, and subsequent cell death. Here, we show that NF-kappaB, p53, and AP1 are activated in Env-elicited apoptosis. The nuclear factor kappaB (NF-kappaB) super repressor had an antimitotic and antiapoptotic effect and prevented the Env-elicited phosphorylation of p53 on serine 15 and 46, as well as the activation of AP1. Transfection with dominant-negative p53 abolished apoptosis and AP1 activation. Signs of NF-kappaB and p53 activation were also detected in lymph node biopsies from HIV-1-infected individuals. Microarrays revealed that most (85%) of the transcriptional effects of HIV-1 Env were blocked by the p53 inhibitor pifithrin-alpha. Macroarrays led to the identification of several Env-elicited, p53-dependent proapoptotic transcripts, in particular Puma, a proapoptotic "BH3-only" protein from the Bcl-2 family known to activate Bax/Bak. Down modulation of Puma by antisense oligonucleotides, as well as RNA interference of Bax and Bak, prevented Env-induced apoptosis. HIV-1-infected primary lymphoblasts up-regulated Puma in vitro. Moreover, circulating CD4+ lymphocytes from untreated, HIV-1-infected donors contained enhanced amounts of Puma protein, and these elevated Puma levels dropped upon antiretroviral therapy. Altogether, these data indicate that NF-kappaB and p53 cooperate as the dominant proapoptotic transcription factors participating in HIV-1 infection.

Effects of age and sedentary lifestyle on skeletal muscle NF-kappaB signaling in men.

Science.gov (United States)

Buford, Thomas W; Cooke, Matthew B; Manini, Todd M; Leeuwenburgh, Christiaan; Willoughby, Darryn S

2010-05-01

Nuclear factor kappa B (NF-kappaB) is a critical signaling molecule of disuse-induced skeletal muscle atrophy. However, few studies have carefully investigated whether similar pathways are modulated with physical activity and age. The present study examined lean mass, maximal force production, and skeletal muscle NF-kappaB signaling in 41 men categorized as sedentary (OS, N = 13, 63.85 +/- 6.59 year), physically active (OA, N = 14, 60.71 +/- 5.54 year), or young and sedentary (YS, N = 14, 21.35 +/- 3.84 year). Muscle tissue from the vastus lateralis was assayed for messenger RNA (mRNA) expression of the beta subunit of IkB kinase (IKKbeta), cytosolic protein content of phosphorylated inhibitor of kappa B alpha (pIKBalpha), and nuclear content of NF-kappaB subunits p50 and p65. When compared with YS, OS demonstrated age-related muscle atrophy and reduced isokinetic knee extension torque. Physical activity in older individuals preserved maximal isokinetic knee extension torque. OS muscle contained 50% more pIKBalpha than OA and 61% more pIKBalpha than YS. Furthermore, nuclear p65 was significantly elevated in OS compared with YS. OS muscle did not differ from either of the other two groups for nuclear p50 or for mRNA expression of IKKbeta. These results indicate that skeletal muscle content of nuclear-bound p65 is elevated by age in humans. The elevation in nuclear-bound p65 appears to be at least partially due to significant increases in pIKBalpha. A sedentary lifestyle appears to play some role in increased IKBalpha; however, further research is needed to identify downstream effects of this increase.

Homeostatic NF-κB Signaling in Steady-State Migratory Dendritic Cells Regulates Immune Homeostasis and Tolerance.

Science.gov (United States)

Baratin, Myriam; Foray, Chloe; Demaria, Olivier; Habbeddine, Mohamed; Pollet, Emeline; Maurizio, Julien; Verthuy, Christophe; Davanture, Suzel; Azukizawa, Hiroaki; Flores-Langarica, Adriana; Dalod, Marc; Lawrence, Toby

2015-04-21

Migratory non-lymphoid tissue dendritic cells (NLT-DCs) transport antigens to lymph nodes (LNs) and are required for protective immune responses in the context of inflammation and to promote tolerance to self-antigens in steady-state. However, the molecular mechanisms that elicit steady-state NLT-DC maturation and migration are unknown. By comparing the transcriptome of NLT-DCs in the skin with their migratory counterparts in draining LNs, we have identified a novel NF-κB-regulated gene network specific to migratory DCs. We show that targeted deletion of IKKβ in DCs, a major activator of NF-κB, prevents NLT-DC accumulation in LNs and compromises regulatory T cell conversion in vivo. This was associated with impaired tolerance and autoimmunity. NF-κB is generally considered the prototypical pro-inflammatory transcription factor, but this study describes a role for NF-κB signaling in DCs for immune homeostasis and tolerance that could have implications in autoimmune diseases and immunity. Copyright © 2015 Elsevier Inc. All rights reserved.

Homeostatic regulatory role of Pokemon in NF-κB signaling: stimulating both p65 and IκBα expression in human hepatocellular carcinoma cells.

Science.gov (United States)

Zhang, Nan-Nan; Sun, Qin-Sheng; Chen, Zhe; Liu, Feng; Jiang, Yu-Yang

2013-01-01

NF-κB consists of p50, p65 (RelA), p52, c-Rel, and RelB, and among them p65 is a representative protein to investigate the regulation and function of this signaling. NF-κB integrates inflammation and carcinogenesis and regulates the expression of a variety of genes in response to immunity, inflammation, and apoptosis. IκBα acts as an inhibitor of NF-κB through forming an inactive NF-κB/IκBα complex. Pokemon is a ubiquitous transcription factor involved in different signaling pathways, playing a pivotal role in cell proliferation, anti-apoptosis, embryonic development, and maintenance. In this study, we found that p65 and IκBα are both novel regulatory targets of Pokemon. Ectopic expression of Pokemon in immortalized liver cells HL7702 enhanced p65 and IκBα expression, whereas silencing of Pokemon in hepatocellular carcinoma cells QGY7703 reduced cellular p65 levels. ChIP assay and targeted mutagenesis revealed that Pokemon directly binds to the element of -434 to -430 bp in p65 promoter and of -453 to -448 bp in IκBα promoter and stimulates luciferase reporter gene expression. Co-transfection of Pokemon with p65 or IκBα promoter-reporter notably enhanced their promoter activity. These data suggest that Pokemon activates the expression of both p65 and IκBα by sequence-specific binding to their promoters and plays a dual role in regulating NF-κB signaling.

CD137 is induced by the CD40 signal on chronic lymphocytic leukemia B cells and transduces the survival signal via NF-κB activation.

Directory of Open Access Journals (Sweden)

Yukana Nakaima

Full Text Available CD137 is a member of the tumor necrosis factor receptor family that is expressed on activated T cells. This molecule provides a co-stimulatory signal that enhances the survival, and differentiation of cells, and has a crucial role in the development of CD8 cytotoxic T cells and anti-tumor immunity. Here we report that CD137 expression is also induced on normal or malignant human B cells by CD40 ligation by its ligand CD154. This CD137 induction was more prominent in chronic lymphocytic leukemia (CLL cells than in other types of B cells. CD137 stimulation on B cells by its ligand induced the nuclear translocation of p52 (a non-canonical NF-κB factor. In agreement with this finding, expression of the survival factor BCL-XL was upregulated. Consequently, the CD137 signal augmented the survival of CD154-stimulated CLL B cells in vitro. This unexpected induction of CD137 on B cells by CD40 signal may influence the clinical course of CLL.

Fisetin-treatment alleviates airway inflammation through inhbition of MyD88/NF-κB signaling pathway.

Science.gov (United States)

Huang, Wei; Li, Ming-Li; Xia, Ming-Yue; Shao, Jian-Ying

2018-07-01

Asthma is a common chronic airway inflammation disease and is considered as a major public health problem. Fisetin (3,3',4',7-tetrahydroxyflavone) is a naturally occurring flavonoid abundantly found in different vegetables and fruits. Fisetin has been reported to exhibit various positive biological effects, including anti-proliferative, anticancer, anti-oxidative and neuroprotective effects. We evaluated the effects of fisetin on allergic asthma regulation in mice. Mice were first sensitized, then airway-challenged with ovalbumin (OVA). Whether fisetin treatment attenuated OVA-induced airway inflammation was examined via inflammation inhibition through MyD88-related NF-κB (p65) signaling pathway. Mice were divided into the control (Con), OVA-induced asthma (Mod), 40 (FL) and 50 (FH) mg/kg fisetin-treated OVA-induced asthma groups. Our results found that OVA-induced airway inflammation in mice caused a significant inflammatory response via the activation of MyD88 and NF-κB signaling pathways, leading to release of pro-inflammatory cytokines. In contrast, fisetin-treated mice after OVA induction inhibited activation of MyD88 and NF-κB signaling pathways, resulting in downregulation of pro-inflammatory cytokine secretion. Further, fisetin significantly ameliorated the airway hyperresponsiveness (AHR) towards methacholine (Mch). In addition, fisetin reduced the number of eosinophil, monocyte, neutrophil and total white blood cell in the bronchoalveolar lavage fluid (BALF) of OVA-induced mice. The serum and BALF samples obtained from the OVA-induced mice with fisetin showed lower levels of pro-inflammatory cytokines. The results of our study illustrated that fisetin may be a new promising candidate to inhibit airway inflammation response induced by OVA.

Calcineurin inhibitors recruit protein kinases JAK2 and JNK, TLR signaling and the UPR to activate NF-κB-mediated inflammatory responses in kidney tubular cells

International Nuclear Information System (INIS)

González-Guerrero, Cristian; Ocaña-Salceda, Carlos; Berzal, Sergio; Carrasco, Susana; Fernández-Fernández, Beatriz

2013-01-01

The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus are key drugs in current immunosuppressive regimes for solid organ transplantation. However, they are nephrotoxic and promote death and profibrotic responses in tubular cells. Moreover, renal inflammation is observed in CNI nephrotoxicity but the mechanisms are poorly understood. We have now studied molecular pathways leading to inflammation elicited by the CNIs in cultured and kidney tubular cells. Both CsA and tacrolimus elicited a proinflammatory response in tubular cells as evidenced by a transcriptomics approach. Transcriptomics also suggested several potential pathways leading to expression of proinflammatory genes. Validation and functional studies disclosed that in tubular cells, CNIs activated protein kinases such as the JAK2/STAT3 and TAK1/JNK/AP-1 pathways, TLR4/Myd88/IRAK signaling and the Unfolded Protein Response (UPR) to promote NF-κB activation and proinflammatory gene expression. CNIs also activated an Nrf2/HO-1-dependent compensatory response and the Nrf2 activator sulforaphane inhibited JAK2 and JNK activation and inflammation. A murine model of CsA nephrotoxicity corroborated activation of the proinflammatory pathways identified in cell cultures. Human CNIs nephrotoxicity was also associated with NF-κB, STAT3 and IRE1α activation. In conclusion, CNIs recruit several intracellular pathways leading to previously non-described proinflammatory actions in renal tubular cells. Identification of these pathways provides novel clues for therapeutic intervention to limit CNIs nephrotoxicity. - Highlights: • Molecular mechanisms modulating CNI renal inflammation were investigated. • Kinases, immune receptors and ER stress mediate the inflammatory response to CNIs. • Several intracellular pathways activate NF-κB in CNIs-treated tubular cells. • A NF-κB-dependent cytokine profile characterizes CNIs-induced inflammation. • CNI nephrotoxicity was associated to inflammatory

Andrographolide Inhibits Inflammatory Cytokines Secretion in LPS-Stimulated RAW264.7 Cells through Suppression of NF-κB/MAPK Signaling Pathway.

Science.gov (United States)

Li, Yu; He, Shengnan; Tang, Jishun; Ding, Nana; Chu, Xiaoyan; Cheng, Lianping; Ding, Xuedong; Liang, Ting; Feng, Shibin; Rahman, Sajid Ur; Wang, Xichun; Wu, Jinjie

2017-01-01

Andrographolide, the main active component extracted from Andrographis paniculata (Burm.f.) Wall. ex Nees, exerts anti-inflammatory effects; however, the principal molecular mechanisms remain unclear. The objective of this study was to investigate the molecular mechanisms of Andrographolide in modifying lipopolysaccharide- (LPS-) induced signaling pathway in RAW264.7 cells. An in vitro model of inflammation was induced by LPS in mouse RAW264.7 cells in the presence of Andrographolide. The concentration and expression levels of proinflammatory cytokines were determined by an enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. The nuclear level of NF- κ B was measured by an electrophoretic mobility shift assay (EMSA). The expression levels of NF- κ B, p38, ERK, and JNK were determined by western blot. Andrographolide dose-dependently inhibited the release and mRNA expression of TNF- α , IL-6, and IL-1 β in LPS-stimulated RAW264.7 cells. The nuclear level of p65 protein was decreased in Andrographolide treatment group. Western blot analysis showed that Andrographolide suppressed LPS-induced NF- κ B activation and the phosphorylation of IkBa, ERK1/2, JNK, and p38. These results suggest that Andrographolide exerts an anti-inflammatory effect by inhibiting the activation of NF- κ B/MAPK signaling pathway and the induction of proinflammatory cytokines.

Andrographolide Inhibits Inflammatory Cytokines Secretion in LPS-Stimulated RAW264.7 Cells through Suppression of NF-κB/MAPK Signaling Pathway

Directory of Open Access Journals (Sweden)

Yu Li

2017-01-01

Full Text Available Andrographolide, the main active component extracted from Andrographis paniculata (Burm.f. Wall. ex Nees, exerts anti-inflammatory effects; however, the principal molecular mechanisms remain unclear. The objective of this study was to investigate the molecular mechanisms of Andrographolide in modifying lipopolysaccharide- (LPS- induced signaling pathway in RAW264.7 cells. An in vitro model of inflammation was induced by LPS in mouse RAW264.7 cells in the presence of Andrographolide. The concentration and expression levels of proinflammatory cytokines were determined by an enzyme-linked immunosorbent assay (ELISA and quantitative real-time polymerase chain reaction (qRT-PCR, respectively. The nuclear level of NF-κB was measured by an electrophoretic mobility shift assay (EMSA. The expression levels of NF-κB, p38, ERK, and JNK were determined by western blot. Andrographolide dose-dependently inhibited the release and mRNA expression of TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells. The nuclear level of p65 protein was decreased in Andrographolide treatment group. Western blot analysis showed that Andrographolide suppressed LPS-induced NF-κB activation and the phosphorylation of IkBa, ERK1/2, JNK, and p38. These results suggest that Andrographolide exerts an anti-inflammatory effect by inhibiting the activation of NF-κB/MAPK signaling pathway and the induction of proinflammatory cytokines.

Reduced skeletal muscle inhibitor of kappaB beta content is associated with insulin resistance in subjects with type 2 diabetes: reversal by exercise training.

Science.gov (United States)

Sriwijitkamol, Apiradee; Christ-Roberts, Christine; Berria, Rachele; Eagan, Phyllis; Pratipanawatr, Thongchai; DeFronzo, Ralph A; Mandarino, Lawrence J; Musi, Nicolas

2006-03-01

Skeletal muscle insulin resistance plays a key role in the pathogenesis of type 2 diabetes. It recently has been hypothesized that excessive activity of the inhibitor of kappaB (IkappaB)/nuclear factor kappaB (NFkappaB) inflammatory pathway is a mechanism underlying skeletal muscle insulin resistance. However, it is not known whether IkappaB/NFkappaB signaling in muscle from subjects with type 2 diabetes is abnormal. We studied IkappaB/NFkappaB signaling in vastus lateralis muscle from six subjects with type 2 diabetes and eight matched control subjects. Muscle from type 2 diabetic subjects was characterized by a 60% decrease in IkappaB beta protein abundance, an indicator of increased activation of the IkappaB/NFkappaB pathway. IkappaB beta abundance directly correlated with insulin-mediated glucose disposal (Rd) during a hyperinsulinemic (40 mU x m(-2) x min(-1))-euglycemic clamp (r = 0.63, P = 0.01), indicating that increased IkappaB/NFkappaB pathway activity is associated with muscle insulin resistance. We also investigated whether reversal of this abnormality could be a mechanism by which training improves insulin sensitivity. In control subjects, 8 weeks of aerobic exercise training caused a 50% increase in both IkappaB alpha and IkappaB beta protein. In subjects with type 2 diabetes, training increased IkappaB alpha and IkappaB beta protein to levels comparable with that of control subjects, and these increments were accompanied by a 40% decrease in tumor necrosis factor alpha muscle content and a 37% increase in insulin-stimulated glucose disposal. In summary, subjects with type 2 diabetes have reduced IkappaB protein abundance in muscle, suggesting excessive activity of the IkappaB/NFkappaB pathway. Moreover, this abnormality is reversed by exercise training.

Veronicastrum axillare Alleviates Ethanol-Induced Injury on Gastric Epithelial Cells via Downregulation of the NF-kB Signaling Pathway

Directory of Open Access Journals (Sweden)

Wei-chun Zhao

2017-01-01

Full Text Available We used human gastric epithelial cells (GES-1 line in an ethanol-induced cell damage model to study the protective effect of Veronicastrum axillare and its modulation to NF-κB signal pathway. The goal was to probe the molecular mechanism of V. axillare decoction in the prevention of gastric ulcer and therefore provide guidance in the clinical application of V. axillare on treating injuries from chronic nephritis, pleural effusion, gastric ulcer, and other ailments. The effects of V. axillare-loaded serums on cell viability were detected by MTT assays. Enzyme-linked immunosorbent assay (ELISA and Real-Time PCR methods were used to analyze the protein and mRNA expression of TNF-α, NF-κB, IκBα, and IKKβ. The results showed that V. axillare-loaded serum partially reversed the damaging effects of ethanol and NF-κB activator (phorbol-12-myristate-13-acetate: PMA and increased cell viability. The protein and mRNA expressions of TNF-α, NF-κB, IκBα, and IKKβ were significantly upregulated by ethanol and PMA while they were downregulated by V. axillare-loaded serum. In summary, V. axillare-loaded serum has significantly protective effect on GES-1 against ethanol-induced injury. The protective effect was likely linked to downregulation of TNF-α based NF-κB signal pathway.

Quantification of cellular NEMO content and its impact on NF-κB activation by genotoxic stress.

Directory of Open Access Journals (Sweden)

Byounghoon Hwang

Full Text Available NF-κB essential modulator, NEMO, plays a key role in canonical NF-κB signaling induced by a variety of stimuli, including cytokines and genotoxic agents. To dissect the different biochemical and functional roles of NEMO in NF-κB signaling, various mutant forms of NEMO have been previously analyzed. However, transient or stable overexpression of wild-type NEMO can significantly inhibit NF-κB activation, thereby confounding the analysis of NEMO mutant phenotypes. What levels of NEMO overexpression lead to such an artifact and what levels are tolerated with no significant impact on NEMO function in NF-κB activation are currently unknown. Here we purified full-length recombinant human NEMO protein and used it as a standard to quantify the average number of NEMO molecules per cell in a 1.3E2 NEMO-deficient murine pre-B cell clone stably reconstituted with full-length human NEMO (C5. We determined that the C5 cell clone has an average of 4 x 10(5 molecules of NEMO per cell. Stable reconstitution of 1.3E2 cells with different numbers of NEMO molecules per cell has demonstrated that a 10-fold range of NEMO expression (0.6-6x10(5 molecules per cell yields statistically equivalent NF-κB activation in response to the DNA damaging agent etoposide. Using the C5 cell line, we also quantified the number of NEMO molecules per cell in several commonly employed human cell lines. These results establish baseline numbers of endogenous NEMO per cell and highlight surprisingly normal functionality of NEMO in the DNA damage pathway over a wide range of expression levels that can provide a guideline for future NEMO reconstitution studies.

Insulin receptor substrate-3, interacting with Bcl-3, enhances p50 NF-{kappa}B activity

Energy Technology Data Exchange (ETDEWEB)

Kabuta, Tomohiro [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502 (Japan); Hakuno, Fumihiko; Cho, Yoshitake; Yamanaka, Daisuke; Chida, Kazuhiro [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Asano, Tomoichiro [Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8551 (Japan); Wada, Keiji [Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502 (Japan); Takahashi, Shin-Ichiro, E-mail: atkshin@mail.ecc.u-tokyo.ac.jp [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan)

2010-04-09

The insulin receptor substrate (IRS) proteins are major substrates of both insulin receptor and insulin-like growth factor (IGF)-I receptor tyrosine kinases. Previously, we reported that IRS-3 is localized to both cytosol and nucleus, and possesses transcriptional activity. In the present study, we identified Bcl-3 as a novel binding protein to IRS-3. Bcl-3 is a nuclear protein, which forms a complex with the homodimer of p50 NF-{kappa}B, leading to enhancement of transcription through p50 NF-{kappa}B. We found that Bcl-3 interacts with the pleckstrin homology domain and the phosphotyrosine binding domain of IRS-3, and that IRS-3 interacts with the ankyrin repeat domain of Bcl-3. In addition, IRS-3 augmented the binding activity of p50 to the NF-{kappa}B DNA binding site, as well as the tumor necrosis factor (TNF)-{alpha}-induced transcriptional activity of NF-{kappa}B. Lastly, IRS-3 enhanced NF-{kappa}B-dependent anti-apoptotic gene induction and consequently inhibited TNF-{alpha}-induced cell death. This series of results proposes a novel function for IRS-3 as a transcriptional regulator in TNF-{alpha} signaling, distinct from its function as a substrate of insulin/IGF receptor kinases.

Alteration in Inflammation-related miR-146a Expression in NF-KB Signaling Pathway in Diabetic Rat Hippocampus.

Science.gov (United States)

Habibi, Fatemeh; Ghadiri Soufi, Farhad; Ghiasi, Rafighe; Khamaneh, Amir Mahdi; Alipour, Mohammad Reza

2016-03-01

The purpose of the present study is to evaluate the expression of miR-146a gene, its adaptor genes (TRAF6, NF-KB, and IRAK1), and possible changes in the cellular signaling pathway in diabetic hippocampus tissue. Male Sprague-Dawley rats are randomly selected and divided into control and diabetic (n=6) groups. Diabetes induced by the single-dose injection of nicotinamide [110 mg/kg, (i.p.)], 15 min before streptozotocin (50 mg/kg; i.p.) in 12-h fasted rats. The rats are kept at the laboratory for two months. After anaesthetization, hippocampus of the rats was removed in order to measure the expression of miR-146a, NFK-B, IRAK1, and TRAF6 genes using real-time PCR and activity of NF-KB as well as amount of apoptosis rate using ELISA. The results indicated a reduction in expression of miR-146a and an increase in expression of IRAK1, NF-KB, and TRAF6 genes in the hippocampus of diabetic rats compared to control. Also it reveals an increase in the activity of NF-KB and apoptosis rate in the hippocampus of diabetic rats. Our results report the probability that reduction of miR-146a expression in the negative feedback loop between miR-146a and NF-KB increases NF-kB expression and thus intensifies inflammation and apoptosis in hippocampus.

Effects of Age and Sedentary Lifestyle on Skeletal Muscle NF-κB Signaling in Men

Science.gov (United States)

Buford, Thomas W.; Cooke, Matthew B.; Manini, Todd M.; Leeuwenburgh, Christiaan

2010-01-01

Background. Nuclear factor kappa B (NF-κB) is a critical signaling molecule of disuse-induced skeletal muscle atrophy. However, few studies have carefully investigated whether similar pathways are modulated with physical activity and age. Methods. The present study examined lean mass, maximal force production, and skeletal muscle NF-κB signaling in 41 men categorized as sedentary (OS, N = 13, 63.85 ± 6.59 year), physically active (OA, N = 14, 60.71 ± 5.54 year), or young and sedentary (YS, N = 14, 21.35 ± 3.84 year). Muscle tissue from the vastus lateralis was assayed for messenger RNA (mRNA) expression of the β subunit of IkB kinase (IKKβ), cytosolic protein content of phosphorylated inhibitor of kappa B alpha (pIKBα), and nuclear content of NF-κB subunits p50 and p65. Results. When compared with YS, OS demonstrated age-related muscle atrophy and reduced isokinetic knee extension torque. Physical activity in older individuals preserved maximal isokinetic knee extension torque. OS muscle contained 50% more pIKBα than OA and 61% more pIKBα than YS. Furthermore, nuclear p65 was significantly elevated in OS compared with YS. OS muscle did not differ from either of the other two groups for nuclear p50 or for mRNA expression of IKKβ. Conclusions. These results indicate that skeletal muscle content of nuclear-bound p65 is elevated by age in humans. The elevation in nuclear-bound p65 appears to be at least partially due to significant increases in pIKBα. A sedentary lifestyle appears to play some role in increased IKBα; however, further research is needed to identify downstream effects of this increase. PMID:20045871

Resistin Enhances Inflammatory Cytokine Production in Coronary Artery Tissues by Activating the NF-κB Signaling

Directory of Open Access Journals (Sweden)

Fang Gao

2016-01-01

Full Text Available Purpose. Kawasaki disease (KD is a systemic vasculitis and is a leading cause of coronary artery lesions (CALs in childhood. Our previous study has shown higher levels of serum Resistin in KD patients with coronary aneurysm. This study aimed at examining the association of Resistin with inflammatory cytokine expression in mouse model of coronary arteritis and determining the potential mechanisms. Methods. C57BL/6 mice were injected with Lactobacillus cell wall extract (LCWE to induce coronary arteritis. The relative levels of Resistin, TNF-α, IL-1β, and MMP-9 expression and inflammatory infiltrates in the coronary arteries were determined longitudinally by quantitative RT-PCR, ELISA, and histology. The effect of TLR4 and NF-κB activation on Resistin-induced TNF-α and IL-1β expression in human coronary artery endothelium cells (HCAECs was examined by quantitative RT-PCR. Results. Higher levels of Resistin, TNF-α, IL-1β, and MMP-9 expression were associated with the degrees of inflammatory infiltrates in the coronary artery walls of the LCWE-injected mice. Resistin enhanced TNF-α and IL-1β expression in HCAECs at 18 or 24 hours after stimulation. Pretreatment with anti-TLR4 attenuated Resistin-enhanced IL-1β, but not TNF-α, expression and pretreatment with parthenolide or QNZ demolished Resistin-enhanced TNF-α expression in HACECs. Pretreatment with parthenolide, but not QNZ, blocked Resistin-enhanced IL-1β expression in HCAECs. Conclusion. Resistin may enhance inflammation by cross-talking with TLR4/NF-κB signaling during the development of coronary arteritis in mice.

Regulation of HTLV-1 Tax Stability, Cellular Trafficking and NF-κB Activation by the Ubiquitin-Proteasome Pathway

Science.gov (United States)

Lavorgna, Alfonso; Harhaj, Edward William

2014-01-01

Human T-cell leukemia virus type 1 (HTLV-1) is a complex retrovirus that infects CD4+ T cells and causes adult T-cell leukemia/lymphoma (ATLL) in 3%–5% of infected individuals after a long latent period. HTLV-1 Tax is a trans-activating protein that regulates viral gene expression and also modulates cellular signaling pathways to enhance T-cell proliferation and cell survival. The Tax oncoprotein promotes T-cell transformation, in part via constitutive activation of the NF-κB transcription factor; however, the underlying mechanisms remain unknown. Ubiquitination is a type of post-translational modification that occurs in a three-step enzymatic cascade mediated by E1, E2 and E3 enzymes and regulates protein stability as well as signal transduction, protein trafficking and the DNA damage response. Emerging studies indicate that Tax hijacks the ubiquitin machinery to activate ubiquitin-dependent kinases and downstream NF-κB signaling. Tax interacts with the E2 conjugating enzyme Ubc13 and is conjugated on C-terminal lysine residues with lysine 63-linked polyubiquitin chains. Tax K63-linked polyubiquitination may serve as a platform for signaling complexes since this modification is critical for interactions with NEMO and IKK. In addition to NF-κB signaling, mono- and polyubiquitination of Tax also regulate its subcellular trafficking and stability. Here, we review recent advances in the diverse roles of ubiquitin in Tax function and how Tax usurps the ubiquitin-proteasome pathway to promote oncogenesis. PMID:25341660

TRIM29 Overexpression Promotes Proliferation and Survival of Bladder Cancer Cells through NF-κB Signaling.

Science.gov (United States)

Tan, Shu-Tao; Liu, Sheng-Ye; Wu, Bin

2016-10-01

TRIM29 overexpression has been reported in several human malignancies and showed correlation with cancer cell malignancy. The aim of the current study is to examine its clinical significance and biological roles in human bladder cancer tissues and cell lines. A total of 102 cases of bladder cancer tissues were examined for TRIM29 expression by immunohistochemistry. siRNA and plasmid transfection were performed in 5637 and BIU-87 cell lines. Cell Counting Kit-8, flow cytometry, western blot, and real-time polymerase chain reaction were performed to examine its biological roles and mechanism in bladder cancer cells. We found that TRIM29 overexpression showed correlation with invading depth (p=0.0087). Knockdown of TRIM29 expression in bladder cancer cell line 5637 inhibited cell growth rate and cell cycle transition while its overexpression in BIU-87 cells accelerated cell proliferation and cell cycle progression. TRIM29 overexpression also inhibited cell apoptosis induced by cisplatin. In addition, we demonstrated that TRIM29 depletion decreased while its overexpression led to upregulated expression of cyclin D1, cyclin E, and Bcl-2. We also showed that TRIM29 knockdown inhibited protein kinase C (PKC) and nuclear factor κB (NF-κB) signaling while its overexpression stimulated the PKC and NF-κB pathways. BAY 11-7082 (NF-κB inhibitor) partly attenuated the effect of TRIM29 on expression of cyclin and Bcl-2. Treatment with PKC inhibitor staurosporine resulted in ameliorated TRIM29 induced activation of NF-κB. The current study demonstrated that TRIM29 upregulates cyclin and Bcl family proteins level to facilitate malignant cell growth and inhibit drug-induced apoptosis in bladder cancer, possibly through PKC-NF-κB signaling pathways.

Central inhibition of IKKβ/NF-κB signaling attenuates high-fat diet-induced obesity and glucose intolerance.

Science.gov (United States)

Benzler, Jonas; Ganjam, Goutham K; Pretz, Dominik; Oelkrug, Rebecca; Koch, Christiane E; Legler, Karen; Stöhr, Sigrid; Culmsee, Carsten; Williams, Lynda M; Tups, Alexander

2015-06-01

Metabolic inflammation in the central nervous system might be causative for the development of overnutrition-induced metabolic syndrome and related disorders, such as obesity, leptin and insulin resistance, and type 2 diabetes. Here we investigated whether nutritive and genetic inhibition of the central IκB kinase β (IKKβ)/nuclear factor-κB (NF-κB) pathway in diet-induced obese (DIO) and leptin-deficient mice improves these metabolic impairments. A known prominent inhibitor of IKKβ/NF-κB signaling is the dietary flavonoid butein. We initially determined that oral, intraperitoneal, and intracerebroventricular administration of this flavonoid improved glucose tolerance and hypothalamic insulin signaling. The dose-dependent glucose-lowering capacity was profound regardless of whether obesity was caused by leptin deficiency or high-fat diet (HFD). To confirm the apparent central role of IKKβ/NF-κB signaling in the control of glucose and energy homeostasis, we genetically inhibited this pathway in neurons of the arcuate nucleus, one key center for control of energy homeostasis, via specific adeno-associated virus serotype 2-mediated overexpression of IκBα, which inhibits NF-κB nuclear translocation. This treatment attenuated HFD-induced body weight gain, body fat mass accumulation, increased energy expenditure, and reduced arcuate suppressor of cytokine signaling 3 expression, indicative for enhanced leptin signaling. These results reinforce a specific role of central proinflammatory IKKβ/NF-κB signaling in the development and potential treatment of DIO-induced comorbidities. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

[Notch1 signaling participates in the release of inflammatory mediators in mouse RAW264.7 cells via activating NF-κB pathway].

Science.gov (United States)

Zhao, Hongwei; Xu, Che Nan; Huang, Chao; Jiang, Jinzhi; Li, Liangchang

2017-10-01

Objective To study the effect of Notch1 signaling on the release of inflammatory mediators in lipopolysaccharide (LPS)-induced macrophages and the related mechanism. Methods The expressions of Notch1 and hairy and enhancer of split 1 (Hes1) mRNAs were investigated by reverse transcription PCR (RT-PCR) in mouse RAW264.7 cells after stimulated with 100 ng/mL LPS for 8 hours. Prior to stimulation with LPS, mouse RAW264.7 cells were treated with DAPT (10 μmol/L), an inhibitor of Notch1 signaling, for 1 hour. The concentrations of tumor necrosis factor (TNF-α), interleukin 1β (IL-1β), IL-6, nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) in cell culture media were measured by ELISA. The mRNA levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were examined by RT-PCR. The protein levels of iNOS, COX-2, nuclear factor kappa Bp65 (NF-κBp65) and phosphorylated nuclear factor κB inhibitor α (p-IκBα) were detected by Western blotting. Results The expressions of Notch1 and Hes1 mRNAs significantly increased in mouse RAW264.7 cells after stimulated with LPS. The levels of TNF-α, IL-1β, IL-6, NO and PGE 2 were significantly up-regulated in cell culture media after stimulated with LPS, but the levels of those inflammatory mediators were reduced by DAPT. The mRNA and protein levels of iNOS and COX-2 were significant raised in mouse RAW264.7 cells after stimulated with LPS, while they were inhibited by DAPT. Both IκBα-phosphorylation and NF-κBp65 translocation into nuclear in LPS-induced RAW264.7 cells were also inhibited by DAPT. Conclusion Notch1 signaling activates NF-κB to participate in LPS-induced inflammatory mediator release in macrophages.

Dusuqing granules (DSQ) suppress inflammation in Klebsiella pneumonia rat via NF-κB/MAPK signaling.

Science.gov (United States)

Mei, Xue; Wang, Hao-Xun; Li, Jian-Sheng; Liu, Xiao-Hui; Lu, Xiao-Fan; Li, Ya; Zhang, Wei-Yu; Tian, Yan-Ge

2017-04-17

Dusuqing granules (DSQ) have been used in the treatment of bacterial pneumonia clinically, with remarkable benefits. This study was initiated to explore the effects of DSQ on pulmonary inflammation by regulating nuclear factor (NF)-κB/mitogen-activated protein kinase (MAPK) signaling in bacterial pneumonia rats. Rat model was duplicated with Klebsiella pneumonia by a one-time intratracheal injection. Rats were randomized into control, model, DSQ and levofloxacin (LVX) groups. After administrated with appropriate medicines for 7 days, lung tissues were harvested and prepared for pathological analysis, and interleukin (IL)-1, IL-6, monocyte chemotactic protein (MCP)-1and macrophage inflammatory protein (MIP)-2 detections. NF-κB mRNA was measured by real-time qPCR, and the phosphorylation and total proteins of P38MAPK, JNK46/54, ERK42/44 were determined by Western blotting. Marked pathological impairments were observed in model rats, whereas were improved in DSQ group. The cytokines levels, NF-κB mRNA expression and the phosphorylation of P38MAPK, JNK46/54 and ERK42/44 proteins were significantly higher in model group, and were significantly depressed in DSQ group. The protective effects of DSQ on Klebsiella pneumonia might be attributed to its inactivative effects of NF-κB/ MAPK pathway.

Fisetin, a dietary flavonoid, ameliorates experimental colitis in mice: Relevance of NF-κB signaling.

Science.gov (United States)

Sahu, Bidya Dhar; Kumar, Jerald Mahesh; Sistla, Ramakrishna

2016-02-01

Fisetin, a dietary flavonoid, is commonly found in many fruits and vegetables. Although studies indicate that fisetin has an anti-inflammatory property, little is known about its effects on intestinal inflammation. The present study investigated the effects of the fisetin on dextran sulphate sodium (DSS)-induced murine colitis, an animal model that resembles human inflammatory bowel disease. Fisetin treatment to DSS-exposed mice significantly reduced the severity of colitis and alleviated the macroscopic and microscopic signs of the disease. Moreover, fisetin reduced the levels of myeloperoxidase activity, the production of proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) and the expressions of COX-2 and iNOS in the colon tissues. Further studies revealed that fisetin suppressed the activation of NF-κB (p65) by inhibiting IκBα phosphorylation and NF-κB (p65)-DNA binding activity and attenuated the phosphorylation of Akt and the p38, but not ERK and JNK MAPKs in the colon tissues of DSS-exposed mice. In addition, DSS-induced decline in reduced glutathione (GSH) and the increase in malondialdehyde (MDA) levels were significantly restored by oral fisetin. Furthermore, the results from in vitro studies showed that fisetin significantly reduced the pro-inflammatory cytokine and mediator release and suppressed the degradation and phosphorylation of IκBα with subsequent nuclear translocation of NF-κB (p65) in lipopolysaccharide (LPS)-stimulated mouse primary peritoneal macrophages. These results suggest that fisetin exerts anti-inflammatory activity via inhibition of Akt, p38 MAPK and NF-κB signaling in the colon tissues of DSS-exposed mice. Thus, fisetin may be a promising candidate as pharmaceuticals or nutraceuticals in the treatment of inflammatory bowel disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Aluminum chloride- and norepinephrine-induced immunotoxicity on splenic lymphocytes by activating β2-AR/cAMP/PKA/NF-κB signal pathway in rats.

Science.gov (United States)

Xiu, Chunyu; Ren, Limin; Li, Miao; Liu, Shiming; Zhu, Yanzhu; Liu, Jianyu; Li, Yanfei

2014-12-01

We found in our previous research that aluminum (Al) exposure induced immunotoxicity on spleen and increased norepinephrine (NE) content in serum from rats. However, it is unclear how NE is involved in the AlCl3 immunotoxicity on rats. Therefore, this experiment was designed to explore the mechanism of AlCl3 and NE-induced immunotoxicity on the splenic lymphocytes. Eighty male Wistar rats were orally exposed to AlCl3 (0, 64, 128, and 256 mg/kg BW) through drinking water for 120 days. Al contents in brain and spleen; NE contents in serum and in the hypothalamus; β2-AR density; cAMP content; β2-AR, PKA, and NF-κB mRNA expression levels; and protein expressions of PKA and nuclear NF-κB in splenic lymphocytes of AlCl3-treated rats were examined. The results showed that AlCl3 increased NE content in serum, the β2-AR density, the β2-AR and PKA (C-subunits) mRNA expression levels, cAMP content and the PKA (C-subunits) protein expression levels in lymphocytes, whereas, decreased NE content in the hypothalamus, the NF-κB (p65) mRNA expression level and nuclear NF-κB (p65) protein expression level in lymphocytes. These results indicated that the accumulated AlCl3 in spleen and the increased NE in serum induced the immunotoxicity on splenic lymphocytes by activating β2-AR/cAMP/PKA/NF-κB signal pathway in rats.

Logical network of genotoxic stress-induced NF-kappaB signal transduction predicts putative target structures for therapeutic intervention strategies

Directory of Open Access Journals (Sweden)

Rainer Poltz

2009-12-01

Full Text Available Rainer Poltz1, Raimo Franke1,#, Katrin Schweitzer1, Steffen Klamt2, Ernst-Dieter Gilles2, Michael Naumann11Institute of Experimental Internal Medicine, Otto von Guericke University, Magdeburg, Germany; 2Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany; #Present address: Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, GermanyAbstract: Genotoxic stress is induced by a broad range of DNA-damaging agents and could lead to a variety of human diseases including cancer. DNA damage is also therapeutically induced for cancer treatment with the aim to eliminate tumor cells. However, the effectiveness of radio- and chemotherapy is strongly hampered by tumor cell resistance. A major reason for radio- and chemotherapeutic resistances is the simultaneous activation of cell survival pathways resulting in the activation of the transcription factor nuclear factor-kappa B (NF-κB. Here, we present a Boolean network model of the NF-κB signal transduction induced by genotoxic stress in epithelial cells. For the representation and analysis of the model, we used the formalism of logical interaction hypergraphs. Model reconstruction was based on a careful meta-analysis of published data. By calculating minimal intervention sets, we identified p53-induced protein with a death domain (PIDD, receptor-interacting protein 1 (RIP1, and protein inhibitor of activated STAT y (PIASy as putative therapeutic targets to abrogate NF-κB activation resulting in apoptosis. Targeting these structures therapeutically may potentiate the effectiveness of radio- and chemotherapy. Thus, the presented model allows a better understanding of the signal transduction in tumor cells and provides candidates as new therapeutic target structures.Keywords: apoptosis, Boolean network, cancer therapy, DNA-damage response, NF-κB

Cancer Cell Growth Inhibitory Effect of Bee Venom via Increase of Death Receptor 3 Expression and Inactivation of NF-kappa B in NSCLC Cells

Directory of Open Access Journals (Sweden)

Kyung Eun Choi

2014-07-01

Full Text Available Our previous findings have demonstrated that bee venom (BV has anti-cancer activity in several cancer cells. However, the effects of BV on lung cancer cell growth have not been reported. Cell viability was determined with trypan blue uptake, soft agar formation as well as DAPI and TUNEL assay. Cell death related protein expression was determined with Western blotting. An EMSA was used for nuclear factor kappaB (NF-κB activity assay. BV (1–5 μg/mL inhibited growth of lung cancer cells by induction of apoptosis in a dose dependent manner in lung cancer cell lines A549 and NCI-H460. Consistent with apoptotic cell death, expression of DR3 and DR6 was significantly increased. However, deletion of DRs by small interfering RNA significantly reversed BV induced cell growth inhibitory effects. Expression of pro-apoptotic proteins (caspase-3 and Bax was concomitantly increased, but the NF-κB activity and expression of Bcl-2 were inhibited. A combination treatment of tumor necrosis factor (TNF-like weak inducer of apoptosis, TNF-related apoptosis-inducing ligand, docetaxel and cisplatin, with BV synergistically inhibited both A549 and NCI-H460 lung cancer cell growth with further down regulation of NF-κB activity. These results show that BV induces apoptotic cell death in lung cancer cells through the enhancement of DR3 expression and inhibition of NF-κB pathway.

Porcine arterivirus activates the NF-κB pathway through IκB degradation

International Nuclear Information System (INIS)

Lee, Sang-Myeong; Kleiboeker, Steven B.

2005-01-01

Nuclear factor-kappaB (NF-κB) is a critical regulator of innate and adaptive immune function as well as cell proliferation and survival. The present study demonstrated for the first time that a virus belonging to the Arteriviridae family activates NF-κB in MARC-145 cells and alveolar macrophages. In porcine reproductive and respiratory syndrome virus (PRRSV)-infected cells, NF-κB activation was characterized by translocation of NF-κB from the cytoplasm to the nucleus, increased DNA binding activity, and NF-κB-regulated gene expression. NF-κB activation was increased as PRRSV infection progressed and in a viral dose-dependent manner. UV-inactivation of PRRSV significantly reduced the level of NF-κB activation. Degradation of IκB protein was detected late in PRRSV infection, and overexpression of the dominant negative form of IκBα (IκBαDN) significantly suppressed NF-κB activation induced by PRRSV. However, IκBαDN did not affect viral replication and viral cytopathic effect. PRRSV infection induced oxidative stress in cells by generating reactive oxygen species (ROS), and antioxidants inhibited NF-κB DNA binding activity in PRRSV-infected cells, suggesting ROS as a mechanism by which NF-κB was activated by PRRSV infection. Moreover, NF-κB-dependent expression of matrix metalloproteinase (MMP)-2 and MMP-9 was observed in PRRSV-infected cells, an observation which implies that NF-κB activation is a biologically significant aspect of PRRSV pathogenesis. The results presented here provide a basis for understanding molecular pathways of pathology and immune evasion associated with disease caused by PRRSV

Lymphotoxin-α3 mediates monocyte-endothelial interaction by TNFR I/NF-κB signaling

International Nuclear Information System (INIS)

Suna, Shinichiro; Sakata, Yasuhiko; Shimizu, Masahiko; Nakatani, Daisaku; Usami, Masaya; Matsumoto, Sen; Mizuno, Hiroya; Ozaki, Kouichi; Takashima, Seiji; Takeda, Hiroshi; Tanaka, Toshihiro; Hori, Masatsugu; Sato, Hiroshi

2009-01-01

We recently reported that the single nucleotide polymorphisms of the lymphotoxin-(LT)α gene, a member of the tumor necrosis factor (TNF) family, are closely related to acute myocardial infarction; however, the precise mechanism of LTα signaling in atherogenesis remains unclear. We investigated the role of LTα3, a secreted homotrimer of LTα, in monocyte-endothelial cell adhesion using cultured human umbilical vein endothelial cells (HUVEC). We found that LTα3 induced cell adhesion molecules and activated NF-κB p50 and p65. LTα3 also induced phosphorylation of Akt, phosphorylation and degradation of IκB, nuclear translocation of p65, and increased adhesion of THP1 monocytes to HUVEC. These effects were mediated by TNF receptor (TNFR) I and attenuated by the phosphatidylinositol triphosphate-kinase (PI3K) inhibitors LY294002 and Wortmannin. Thus, LTα3 mediates the monocyte-endothelial interaction via the classical NF-κB pathway following TNFR I/PI3K activation, indicating it may play a role in the development of coronary artery disease.

Light induces translocation of NF-κB p65 to the mitochondria and suppresses expression of cytochrome c oxidase subunit III (COX III) in the rat retina

Energy Technology Data Exchange (ETDEWEB)

Tomita, Hiroshi, E-mail: htomita@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Soft-Path Engineering Research Center (SPERC), Faculty of Science and Engineering, Iwate University, Morioka 020-8551 (Japan); Clinical Research, Innovation and Education Center, Tohoku University Hospital, 1-1 Seiryo, Aoba, Sendai, Miyagi 980-8574 (Japan); Tabata, Kitako, E-mail: ktabata@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Takahashi, Maki, E-mail: mqdelta@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Nishiyama, Fumiaki, E-mail: t2114018@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Sugano, Eriko, E-mail: sseriko@iwate-u.ac.jp [Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551 (Japan); Soft-Path Engineering Research Center (SPERC), Faculty of Science and Engineering, Iwate University, Morioka 020-8551 (Japan)

2016-05-13

The transcription factor nuclear factor kappaB (NF-κB) plays various roles in cell survival, apoptosis, and inflammation. In the rat retina, NF-κB activity increases after exposure to damaging light, resulting in degeneration of photoreceptors. Here, we report that in dark-adapted rats exposed for 6 h to bright white light, the p65 subunit of retinal NF-κB translocates to the mitochondria, an event associated with a decrease in expression of cytochrome c oxidase subunit III (COX III). However, sustained exposure for 12 h depleted p65 from the mitochondria, and enhanced COX III expression. Treatment with the protective antioxidant PBN prior to light exposure prevents p65 depletion in the mitochondria and COX III upregulation during prolonged exposure, and apoptosis in photoreceptor cells. These results indicate that COX III expression is sensitive to the abundance of NF-κB p65 in the mitochondria, which, in turn, is affected by exposure to damaging light. - Highlights: • Damaging light exposure of the retina induces NF-κB p65 mitochondrial translocation. • NF-κB p65 mitochondrial translocation is associated with the decrease of COX III expression. • Prolonged light exposure depletes mitochondrial p65 resulting in the increase in COX III expression. • NF-κB p65 and COX III expression play an important role in the light-induced photoreceptor degeneration.

Light induces translocation of NF-κB p65 to the mitochondria and suppresses expression of cytochrome c oxidase subunit III (COX III) in the rat retina

International Nuclear Information System (INIS)

Tomita, Hiroshi; Tabata, Kitako; Takahashi, Maki; Nishiyama, Fumiaki; Sugano, Eriko

2016-01-01

The transcription factor nuclear factor kappaB (NF-κB) plays various roles in cell survival, apoptosis, and inflammation. In the rat retina, NF-κB activity increases after exposure to damaging light, resulting in degeneration of photoreceptors. Here, we report that in dark-adapted rats exposed for 6 h to bright white light, the p65 subunit of retinal NF-κB translocates to the mitochondria, an event associated with a decrease in expression of cytochrome c oxidase subunit III (COX III). However, sustained exposure for 12 h depleted p65 from the mitochondria, and enhanced COX III expression. Treatment with the protective antioxidant PBN prior to light exposure prevents p65 depletion in the mitochondria and COX III upregulation during prolonged exposure, and apoptosis in photoreceptor cells. These results indicate that COX III expression is sensitive to the abundance of NF-κB p65 in the mitochondria, which, in turn, is affected by exposure to damaging light. - Highlights: • Damaging light exposure of the retina induces NF-κB p65 mitochondrial translocation. • NF-κB p65 mitochondrial translocation is associated with the decrease of COX III expression. • Prolonged light exposure depletes mitochondrial p65 resulting in the increase in COX III expression. • NF-κB p65 and COX III expression play an important role in the light-induced photoreceptor degeneration.

p38 mitogen-activated protein kinase up-regulates LPS-induced NF-κB activation in the development of lung injury and RAW 264.7 macrophages

International Nuclear Information System (INIS)

Kim, Hee J.; Lee, Hui S.; Chong, Young H.; Kang, Jihee Lee

2006-01-01

Clarification of the key regulatory steps that lead to nuclear factor-kappa B (NF-κB) under cellular and pathological conditions is very important. The action of p38 mitogen-activated protein kinase (MAPK) on the upstream of NF-κB activation remains controversial. To examine this issue using an in vivo lung injury model, SB203580, a p38 MAPK inhibitor was given intraorally 1 h prior to lipopolysaccharide (LPS) treatment (intratracheally). The mice were sacrificed 4 h after LPS treatment. SB203580 substantially suppressed LPS-induced rises in p38 MAPK phosphorylation, neutrophil recruitment, total protein content in bronchoalveolar lavage fluid, and apoptosis of bronchoalveolar cells. Furthermore, SB203580 blocked LPS-induced NF-κB activation in lung tissue through down-regulation of serine phosphorylation, degradation of IκB-α, and consequent translocation of the p65 subunit of NF-κB to the nucleus. It is likely that, in cultured RAW 264.7 macrophages, SB203580 also blocked LPS-induced NF-κB activation in a dose-dependent manner. SB203580 inhibited LPS-induced serine phosphorylation, degradation of IκB-α, and tyrosine phosphorylation of p65 NF-κB. These data indicate that p38 MAPK acts upstream of LPS-induced NF-κB activation by modulating the phosphorylation of IκB-α and p65 NF-κB during acute lung injury. Because LPS-stimulated macrophages may contribute to inflammatory lung injury, the inhibition of the p38 MAPK-mediated intracellular signaling pathway leading to NF-κB activation represents a target for the attenuation of lung inflammation and parenchymal damage

Valproic acid inhibits neural progenitor cell death by activation of NF-κB signaling pathway and up-regulation of Bcl-XL

Directory of Open Access Journals (Sweden)

Han Seol

2011-07-01

Full Text Available Abstract Background At the beginning of neurogenesis, massive brain cell death occurs and more than 50% of cells are eliminated by apoptosis along with neuronal differentiation. However, few studies were conducted so far regarding the regulation of neural progenitor cells (NPCs death during development. Because of the physiological role of cell death during development, aberration of normal apoptotic cell death is detrimental to normal organogenesis. Apoptosis occurs in not only neuron but also in NPCs and neuroblast. When growth and survival signals such as EGF or LIF are removed, apoptosis is activated as well as the induction of differentiation. To investigate the regulation of cell death during developmental stage, it is essential to investigate the regulation of apoptosis of NPCs. Methods Neural progenitor cells were cultured from E14 embryonic brains of Sprague-Dawley rats. For in vivo VPA animal model, pregnant rats were treated with VPA (400 mg/kg S.C. diluted with normal saline at E12. To analyze the cell death, we performed PI staining and PARP and caspase-3 cleavage assay. Expression level of proteins was investigated by Western blot and immunocytochemical assays. The level of mRNA expression was investigated by RT-PCR. Interaction of Bcl-XL gene promoter and NF-κB p65 was investigated by ChIP assay. Results In this study, FACS analysis, PI staining and PARP and caspase-3 cleavage assay showed that VPA protects cultured NPCs from cell death after growth factor withdrawal both in basal and staurosporine- or hydrogen peroxide-stimulated conditions. The protective effect of prenatally injected VPA was also observed in E16 embryonic brain. Treatment of VPA decreased the level of IκBα and increased the nuclear translocation of NF-κB, which subsequently enhanced expression of anti-apoptotic protein Bcl-XL. Conclusion To the best of our knowledge, this is the first report to indicate the reduced death of NPCs by VPA at developmentally

MicroRNA-129-5p inhibits the development of autoimmune encephalomyelitis-related epilepsy by targeting HMGB1 through the TLR4/NF-kB signaling pathway.

Science.gov (United States)

Liu, Ai-Hua; Wu, Ya-Ting; Wang, Yu-Ping

2017-06-01

The study aimed to explore the effects of microRNA-129-5p (miR-129-5p) on the development of autoimmune encephalomyelitis (AE)-related epilepsy by targeting HMGB1 through the TLR4/NF-kB signaling pathway in a rat model. AE-related epilepsy models were established. Sprague-Dawley (SD) rats were randomly divided into control, model, miR-129-5p mimics, miR-129-5p inhibitor, HMGB1 shRNA, TLR4/NF-kB (TLR4/NF-kB signaling pathway was inhibited) and miR-129-5p mimics+HMGB1 shRNA groups respectively. Latency to a first epilepsy seizure attack was recorded. Neuronal injuries in the hippocampus regions were detected using HE, Nissl and FJB staining methods 24h following model establishment. Microglial cells were detected by OX-42 immunohistochemistry. Expressions of miR-129-5p, HMGB1 and TLR4/NF-kB signaling pathway-related proteins were detected by qRT-PCR. Protein expressions of HMGB1 and TLR4/NF-kB signaling pathway-related proteins were detected by Western blotting. Dual luciferase reporter gene assay showed that miR-129-5p was negatively targeting HMGB1. Neurons of hippocampal tissues in rats were heavily injured by an injection of lithium chloride. Compared with the model and control groups, neuronal injury of the hippocampus and AE-related epilepsy decreased and microglial cells increased in the miR-129-5p mimics, HMGB1 shRNA and TLR4/NF-kB groups; however, in the miR-129-5p inhibitor group, miR-129-5p expression decreased, HMGB1 expression increased, TLR4/NF-kB signaling pathway was activated, latency to a first epilepsy seizure attack was shortened, and neuronal injury increased. This study provides evidence that miR-129-5p inhibits the development of AE-related epilepsy by suppressing HMGB1 expression and inhibiting TLR4/NF-kB signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Chlamydia abortus Pmp18.1 Induces IL-1β Secretion by TLR4 Activation through the MyD88, NF-κB, and Caspase-1 Signaling Pathways.

Science.gov (United States)

Pan, Qing; Zhang, Qiang; Chu, Jun; Pais, Roshan; Liu, Shanshan; He, Cheng; Eko, Francis O

2017-01-01

The polymorphic membrane protein D (Pmp18D) is a 160-kDa outer membrane protein that is conserved and plays an important role in Chlamydia abortus pathogenesis. We have identified an N-terminal fragment of Pmp18D (designated Pmp18.1) as a possible subunit vaccine antigen. In this study, we evaluated the vaccine potential of Pmp18.1 by investigating its ability to induce innate immune responses in dendritic cells and the signaling pathway(s) involved in rPmp18.1-induced IL-1β secretion. We next investigated the immunomodulatory impact of VCG, in comparison with the more established Th1-promoting adjuvants, CpG and FL, on rPmp18.1-mediated innate immune activation. Finally, the effect of siRNA targeting TLR4, MyD88, NF-κB p50, and Caspase-1 mRNA in DCs on IL-1β cytokine secretion was also investigated. Bone marrow-derived dendritic cells (BMDCs) were stimulated with rPmp18.1 in the presence or absence of VCG or CpG or FL and the magnitude of cytokines produced was assessed using a multiplex cytokine ELISA assay. Expression of costimulatory molecules and Toll-like receptors (TLRs) was analyzed by flow cytometry. Quantitation of intracellular levels of myeloid differentiation factor 88 (MyD88), nuclear factor kappa beta (NF-κB p50/p65), and Caspase-1 was evaluated by Western immunoblotting analysis while NF-κB p65 nuclear translocation was assessed by confocal microscopy. The results showed DC stimulation with rPmp18.1 provoked the secretion of proinflammatory cytokines and upregulated expression of TLRs and co-stimulatory molecules associated with DC maturation. These responses were significantly ( p ≤ 0.001) enhanced by VCG but not CpG or FL. In addition, rPmp18.1 activated the expression of MyD88, NF-κB p50, and Caspase-1 as well as the nuclear expression of NF-κB p65 in treated DCs. Furthermore, targeting TLR4, MyD88, NF-κB p50, and Caspase-1 mRNA in BMDCs with siRNA significantly reduced their expression levels, resulting in decreased IL-1β cytokine

Chlamydia abortus Pmp18.1 Induces IL-1β Secretion by TLR4 Activation through the MyD88, NF-κB, and Caspase-1 Signaling Pathways

Directory of Open Access Journals (Sweden)

Qing Pan

2017-12-01

Full Text Available The polymorphic membrane protein D (Pmp18D is a 160-kDa outer membrane protein that is conserved and plays an important role in Chlamydia abortus pathogenesis. We have identified an N-terminal fragment of Pmp18D (designated Pmp18.1 as a possible subunit vaccine antigen. In this study, we evaluated the vaccine potential of Pmp18.1 by investigating its ability to induce innate immune responses in dendritic cells and the signaling pathway(s involved in rPmp18.1-induced IL-1β secretion. We next investigated the immunomodulatory impact of VCG, in comparison with the more established Th1-promoting adjuvants, CpG and FL, on rPmp18.1-mediated innate immune activation. Finally, the effect of siRNA targeting TLR4, MyD88, NF-κB p50, and Caspase-1 mRNA in DCs on IL-1β cytokine secretion was also investigated. Bone marrow-derived dendritic cells (BMDCs were stimulated with rPmp18.1 in the presence or absence of VCG or CpG or FL and the magnitude of cytokines produced was assessed using a multiplex cytokine ELISA assay. Expression of costimulatory molecules and Toll-like receptors (TLRs was analyzed by flow cytometry. Quantitation of intracellular levels of myeloid differentiation factor 88 (MyD88, nuclear factor kappa beta (NF-κB p50/p65, and Caspase-1 was evaluated by Western immunoblotting analysis while NF-κB p65 nuclear translocation was assessed by confocal microscopy. The results showed DC stimulation with rPmp18.1 provoked the secretion of proinflammatory cytokines and upregulated expression of TLRs and co-stimulatory molecules associated with DC maturation. These responses were significantly (p ≤ 0.001 enhanced by VCG but not CpG or FL. In addition, rPmp18.1 activated the expression of MyD88, NF-κB p50, and Caspase-1 as well as the nuclear expression of NF-κB p65 in treated DCs. Furthermore, targeting TLR4, MyD88, NF-κB p50, and Caspase-1 mRNA in BMDCs with siRNA significantly reduced their expression levels, resulting in decreased IL-1�

Green tea polyphenol epigallocatechin-3-gallate inhibits TLR4 signaling through the 67-kDa laminin receptor on lipopolysaccharide-stimulated dendritic cells

Energy Technology Data Exchange (ETDEWEB)

Byun, Eui-Baek [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Choi, Han-Gyu [Department of Microbiology and Research Institute for Medical Sciences, College of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Sung, Nak-Yun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Byun, Eui-Hong, E-mail: ehbyun80@gmail.com [Department of Microbiology and Research Institute for Medical Sciences, College of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of)

2012-10-05

Highlights: Black-Right-Pointing-Pointer Expressions of CD80, CD86, and MHC class I/II were inhibited by EGCG via 67LR. Black-Right-Pointing-Pointer EGCG-treated DCs inhibited LPS-induced pro-inflammatory cytokines via 67LR. Black-Right-Pointing-Pointer EGCG-treated DCs inhibited MAPKs activation and NF-{kappa}B p65 translocation via 67LR. Black-Right-Pointing-Pointer EGCG elevated the expression of the Tollip protein through 67LR in DCs. -- Abstract: Epigallocatechin-3-gallate (EGCG), a major active polyphenol of green tea, has been shown to down-regulate inflammatory responses in dendritic cells (DCs); however, the underlying mechanism has not been understood. Recently, we identified the 67-kDa laminin receptor (67LR) as a cell-surface EGCG receptor. In this study, we showed the molecular basis for the down-regulation of toll-like receptor 4 (TLR4) signal transduction by EGCG in DCs. The expressions of CD80, CD86, and MHC class I and II, which are molecules essential for antigen presentation by DCs, were inhibited by EGCG via 67LR. In addition, EGCG-treated DCs inhibited lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-{alpha}, interleukin [IL]-1{beta}, and IL-6) and activation of mitogen-activated protein kinases (MAPKs), e.g., extracellular signal-regulated kinase 1/2 (ERK1/2), p38, c-Jun N-terminal kinase (JNK), and nuclear factor {kappa}B (NF-{kappa}B) p65 translocation through 67LR. Interestingly, we also found that EGCG markedly elevated the expression of the Tollip protein, a negative regulator of TLR signaling, through 67LR. These novel findings provide new insight into the understanding of negative regulatory mechanisms of the TLR4 signaling pathway and consequent inflammatory responses that are implicated in the development and progression of many chronic diseases.

EBV induces persistent NF-κB activation and contributes to survival of EBV-positive neoplastic T- or NK-cells.

Directory of Open Access Journals (Sweden)

Honami Takada

Full Text Available Epstein-Barr virus (EBV has been detected in several T- and NK-cell neoplasms such as extranodal NK/T-cell lymphoma nasal type, aggressive NK-cell leukemia, EBV-positive peripheral T-cell lymphoma, systemic EBV-positive T-cell lymphoma of childhood, and chronic active EBV infection (CAEBV. However, how this virus contributes to lymphomagenesis in T or NK cells remains largely unknown. Here, we examined NF-κB activation in EBV-positive T or NK cell lines, SNT8, SNT15, SNT16, SNK6, and primary EBV-positive and clonally proliferating T/NK cells obtained from the peripheral blood of patients with CAEBV. Western blotting, electrophoretic mobility shift assays, and immunofluorescent staining revealed persistent NF-κB activation in EBV-infected cell lines and primary cells from patients. Furthermore, we investigated the role of EBV in infected T cells. We performed an in vitro infection assay using MOLT4 cells infected with EBV. The infection directly induced NF-κB activation, promoted survival, and inhibited etoposide-induced apoptosis in MOLT4 cells. The luciferase assay suggested that LMP1 mediated NF-κB activation in MOLT4 cells. IMD-0354, a specific inhibitor of NF-κB that suppresses NF-κB activation in cell lines, inhibited cell survival and induced apoptosis. These results indicate that EBV induces NF-κB-mediated survival signals in T and NK cells, and therefore, may contribute to the lymphomagenesis of these cells.

Shigella IpaH0722 E3 Ubiquitin Ligase Effector Targets TRAF2 to Inhibit PKC–NF-κB Activity in Invaded Epithelial Cells

Science.gov (United States)

Ashida, Hiroshi; Nakano, Hiroyasu; Sasakawa, Chihiro

2013-01-01

NF-κB plays a central role in modulating innate immune responses to bacterial infections. Therefore, many bacterial pathogens deploy multiple mechanisms to counteract NF-κB activation. The invasion of and subsequent replication of Shigella within epithelial cells is recognized by various pathogen recognition receptors as pathogen-associated molecular patterns. These receptors trigger innate defense mechanisms via the activation of the NF-κB signaling pathway. Here, we show the inhibition of the NF-κB activation by the delivery of the IpaH E3 ubiquitin ligase family member IpaH0722 using Shigella's type III secretion system. IpaH0722 dampens the acute inflammatory response by preferentially inhibiting the PKC-mediated activation of NF-κB by ubiquitinating TRAF2, a molecule downstream of PKC, and by promoting its proteasome-dependent degradation. PMID:23754945

Kaempferol modulates pro-inflammatory NF-κB activation by suppressing advanced glycation endproducts-induced NADPH oxidase

Science.gov (United States)

Kim, Ji Min; Lee, Eun Kyeong; Kim, Dae Hyun; Yu, Byung Pal

2010-01-01

Advanced glycation endproducts (AGE) are oxidative products formed from the reaction between carbohydrates and a free amino group of proteins that are provoked by reactive species (RS). It is also known that AGE enhance the generation of RS and that the binding of AGE to a specific AGE receptor (RAGE) induces the activation of the redox-sensitive, pro-inflammatory transcription factor, nuclear factor-kappa B (NF-ĸB). In this current study, we investigated the anti-oxidative effects of short-term kaempferol supplementation on the age-related formation of AGE and the binding activity of RAGE in aged rat kidney. We further investigated the suppressive action of kaempferol against AGE's ability to stimulate activation of pro-inflammatory NF-ĸB and its molecular mechanisms. For this study, we utilized young (6 months old), old (24 months old), and kaempferol-fed (2 and 4 mg/kg/day for 10 days) old rats. In addition, for the molecular work, the rat endothelial cell line, YPEN-1 was used. The results show that AGE and RAGE were increased during aging and that these increases were blunted by kaempferol. In addition, dietary kaempferol reduced age-related increases in NF-κB activity and NF-ĸB-dependant pro-inflammatory gene activity. The most significant new finding from this study is that kaempferol supplementation prevented age-related NF-κB activation by suppressing AGE-induced nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase). Taken together, our results demonstrated that dietary kaempferol exerts its anti-oxidative and anti-inflammatory actions by modulating the age-related NF-κB signaling cascade and its pro-inflammatory genes by suppressing AGE-induced NADPH oxidase activation. Based on these data, dietary kaempferol is proposed as a possible anti-AGE agent that may have the potential for use in anti-inflammation therapies. PMID:20431987

Presence of Tube isoforms in Litopenaeus vannamei suggests various regulatory patterns of signal transduction in invertebrate NF-κB pathway.

Science.gov (United States)

Li, Chaozheng; Chen, Yixiao; Weng, Shaoping; Li, Sedong; Zuo, Hongliang; Yu, Xiaoqiang; Li, Haoyang; He, Jianguo; Xu, Xiaopeng

2014-02-01

The toll-like receptor (TLR)/NF-κB signaling pathways play critical roles in the innate immune system. The intracellular signal transduction of most TLR pathways in invertebrate cells is triggered by formation of a heterotrimeric complex composed of MyD88, Tube and Pelle. In this study, we identified a Litopenaeus vannamei Pelle (LvPelle) and an isoform of L. vannamei Tube (LvTube) designated as LvTube-1. The interactions among LvPelle, LvTube/LvTube-1 and LvMyD88/LvMyD88-1 were elucidated and their functions during pathogen infections were investigated. Knockdowns of LvPelle and LvTube/LvTube-1 using RNAi strategy led to higher mortalities of shrimps during Vibrio parahemolyticus infection, and could reduce the genome copy number of white spot syndrome virus (WSSV) in the infected muscle tissue but did not affect the mortality caused by WSSV infection. The effects of LvPelle and LvTube/LvTube-1 on promoters containing NF-κB binding motifs were analyzed by dual-luciferase reporter assays and the results demonstrated that LvTube-1 could activate the NF-κB activity to significantly higher level than LvTube did. Moreover, tissue distributions of LvTube and LvTube-1 mRNAs and their expression profiles during pathogen and immune stimulant challenges were different, indicating that they could play different roles in immune responses. This is the first report of Tube isoforms in invertebrates. Together with our previous study on LvMyD88 isoforms, our results suggest that various isoforms of adaptor components may be involved in various regulatory patterns of signal transduction in invertebrate TLR/NF-κB pathway and this could be a strategy adopted by invertebrates to modulate immune responses. Copyright © 2013 Elsevier Ltd. All rights reserved.

A complex relationship between TRAF3 and non-canonical NF-κB2 activation in B lymphocytes

Directory of Open Access Journals (Sweden)

Wai Wai Lin

2013-12-01

Full Text Available The adaptor protein TRAF3 restrains BAFF receptor (BAFFR and CD40-mediated activation of the NF-κB2 pathway in B cells. Mice lacking TRAF3 specifically in B cells revealed the critical role of TRAF3 in restraining homeostatic B cell survival. Furthermore, loss- of-function mutations of the traf3 gene have been associated with human B cell malignancies, especially multiple myeloma (MM. It has been proposed that receptor-induced TRAF3 degradation leads to stabilization of the NF-B inducing kinase NIK, and subsequent NF-κB2 activation. However, it is unclear how receptor-mediated TRAF3 degradation or loss of function contributes to B cell-specific NF-κB2 activation. In the current study, we employed two complementary models to address this question. One utilized a mutant traf3 gene found in a human MM-derived cell line called LP1. The LP1 mutant TRAF3 protein lacks the TRAF-N and TRAF-C domains. Consistent with the paradigm described, expression of LP1 TRAF3 in B cells promoted higher basal levels of NF-κB2 activation compared to Wt TRAF3. However, LP1 did not associate with TRAF2, CD40, or BAFFR, and no LP1 degradation was observed following receptor engagement. Interestingly, LP1 showed enhanced NIK association. Thus, TRAF3 degradation becomes dispensable to activate NF-κB2 when it is unable to associate with TRAF2. In a second model, we examined several mutant forms of BAFFR that are unable to induce NF-κB2 activation in B cells. Signaling to B cells by each of these BAFFR mutants, however, induced levels of TRAF3 degradation similar to those induced by Wt BAFFR. Thus, in B cells, receptor-mediated TRAF3 degradation is not sufficient to promote NF-B2 activation. We thus conclude that there is not a simple linear relationship in B lymphocytes between relative levels of cellular TRAF3, induced TRAF3 degradation, NIK activation and NF-B2 activation.

NF-{kappa}B p50 promotes tumor cell invasion through negative regulation of invasion suppressor gene CRMP-1 in human lung adenocarcinoma cells

Energy Technology Data Exchange (ETDEWEB)

Ming, Gao [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Yeh, P Y [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China); Lu, Y -S [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan, ROC (China); Chang, W C [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Kuo, M -L [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Cheng, A -L [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China)], E-mail: alcheng@ntu.edu.tw

2008-11-14

Lung adenocarcinoma Cl1-5 cells were selected from parental Cl1-0 cells based on their high metastatic potential. In a previous study, CRMP-1, an invasion suppressor gene, was shown to be suppressed in Cl1-5 cells. However, the regulation of CRMP-1 expression has not been explored. In this study, we showed nuclear factor-{kappa}B controls CRMP-1 expression. The electromobility shift assay showed that while Cl1-0 cells exhibited low NF-{kappa}B activity in response to TNF-{alpha}, an abundance of basal and TNF-{alpha}-induced NF-{kappa}B-DNA complex was detected in Cl1-5 cells. Supershift-coupled EMSA and Western blotting of nuclear proteins, however, revealed p50 protein, but not classic p65/p50 heterodimer in the complex. ChIP and EMSA demonstrated that p50 binds to a {kappa}B site residing between -1753 and -1743 of the CRMP-1 promoter region. Transfection of antisense p50 gene into Cl1-5 cells increased the CRMP-1 protein level and decreased the invasive activity of Cl1-5 cells.

Chronic Fluoxetine Treatment Upregulates the Activity of the ERK1/2-NF-κB Signaling Pathway in the Hippocampus and Prefrontal Cortex of Rats Exposed to Forced-Swimming Stress.

Science.gov (United States)

Cui, Jingqiu; Yang, Kun; Yu, Xue; Wang, Jing-Lan; Li, Jie; Zhang, Yong; Li, Hengfen

2016-01-01

The aim of this study was to explore whether or not the antidepressant actions of fluoxetine (FLX) are correlated with extracellular signal-regulated kinase 1 and 2 (ERK1/2) and nuclear factor κ-light chain enhancer of activated B cells (NF-κB) in the hippocampus (HC) and prefrontal cortex (PFC) of rats. A total of 108 male Sprague-Dawley rats were randomly divided into 6 groups of 18 rats each. Group 1 was the control group, while group 2 comprised the depressed model in which rats were subjected to 28 days of forced-swimming stress (FST); groups 3-6 were also subjected to 28 days of FST and treated with FLX once a day for 1 day (group 3; F1d), 1 week (group 4; F1w), 2 weeks (group 5; F2w), or 4 weeks (group 6; F4w). The control group was not subjected to FST or treated with FLX. Behavior tests that included the Morris water maze (MWM) and saccharin preference were performed, and ERK1/2 and NF-κB proteins were assayed using Western blot. The rats in the control group and in groups 5 and 6 (F2w and F4w, respectively) had a significantly shorter average escape latency, needed more attempts in order to successfully cross the platform, and had a greater saccharin preference than those in the depressed group (p < 0.05). In the depressed group, the phosphorylated ERK1/2 (p-ERK1/2) and phosphorylated NF-κB (p-NF-κB) expression in the HC and PFC were lower than in the control group (p < 0.05). Treatment with FLX reversed the changes in the expression of p-ERK1/2 and p-NF-κB in rats in the F2w and F4w groups. In this study, FLX treatment for 2 weeks or longer reversed the impaired spatial learning, memory, and anhedonia observed in the depressed model rats and upregulated the activities of the ERK1/2-NF-κB signaling pathway. © 2016 S. Karger AG, Basel.

TNF-α-induced NF-κB activation promotes myofibroblast differentiation of LR-MSCs and exacerbates bleomycin-induced pulmonary fibrosis.

Science.gov (United States)

Hou, Jiwei; Ma, Tan; Cao, Honghui; Chen, Yabing; Wang, Cong; Chen, Xiang; Xiang, Zou; Han, Xiaodong

2018-03-01

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible lung disease of unknown cause. It has been reported that both lung resident mesenchymal stem cells (LR-MSCs) and tumor necrosis factor-α (TNF-α) play important roles in the development of pulmonary fibrosis. However, the underlying connections between LR-MSCs and TNF-α in the pathogenesis of pulmonary fibrosis are still elusive. In this study, we found that the pro-inflammatory cytokine TNF-α and the transcription factor nuclear factor kappa B (NF-κB) p65 subunit were both upregulated in bleomycin-induced fibrotic lung tissue. In addition, we discovered that TNF-α promotes myofibroblast differentiation of LR-MSCs through activating NF-κB signaling. Interestingly, we also found that TNF-α promotes the expression of β-catenin. Moreover, we demonstrated that suppression of the NF-κB signaling could attenuate myofibroblast differentiation of LR-MSCs and bleomycin-induced pulmonary fibrosis which were accompanied with decreased expression of β-catenin. Our data implicates that inhibition of the NF-κB signaling pathway may provide a therapeutic strategy for pulmonary fibrosis, a disease that warrants more effective treatment approaches. © 2017 Wiley Periodicals, Inc.

Regorafenib induces extrinsic and intrinsic apoptosis through inhibition of ERK/NF-κB activation in hepatocellular carcinoma cells.

Science.gov (United States)

Tsai, Jai-Jen; Pan, Po-Jung; Hsu, Fei-Ting

2017-02-01

The aim of the present study was to investigate the role of NF-κB inactivation in regorafenib-induced apoptosis in human hepatocellular carcinoma SK-HEP-1 cells. SK-HEP-1 cells were treated with different concentrations of the NF-κB inhibitor 4-N-[2-(4-phenoxyphenyl)ethyl]quinazoline-4,6-diamine (QNZ) or regorafenib for different periods. The effects of QNZ and regorafenib on cell viability, expression of NF-κB-modulated anti-apoptotic proteins and apoptotic pathways were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blotting, DNA gel electrophoresis, flow cytometry and NF-κB reporter gene assay. Inhibitors of various kinases including AKT, c-Jun N-terminal kinase (JNK), P38 and extracellular signal-regulated kinase (ERK) were used to evaluate the mechanism of regorafenib-induced NF-κB inactivation. The results demonstrated that both QNZ and regorafenib significantly inhibited the expression of anti-apoptotic proteins and triggered extrinsic and intrinsic apoptosis. We also demonstrated that regorafenib inhibited NF-κB activation through ERK dephosphorylation. Taken all together, our findings indicate that regorafenib triggers extrinsic and intrinsic apoptosis through suppression of ERK/NF-κB activation in SK-HEP-1 cells.

Lycium barbarum polysaccharides improve CCl4-induced liver fibrosis, inflammatory response and TLRs/NF-kB signaling pathway expression in wistar rats.

Science.gov (United States)

Gan, Fang; Liu, Qing; Liu, Yunhuan; Huang, Da; Pan, Cuiling; Song, Suquan; Huang, Kehe

2018-01-01

Lycium barbarum polysaccharides (LBPs) have multiple biological and pharmacological functions, including antioxidant, anti-inflammatory and anticancer activities. This research was conducted to evaluate whether LBPs could alleviate carbon tetrachloride (CCl 4 )-induced liver fibrosis and the underlying signaling pathway mechanism. Fifty male wistar rats were randomly allocated to five groups (n=10): control, CCl 4 and CCl 4 with 400, 800 or 1600mg/kg LBPs, respectively. Each wistar rat from each group was used for blood and tissue collections at the end of experiment. The results showed that CCl 4 induced liver fibrosis as demonstrated by increasing histopathological damage, α-smooth muscle actin expression, aspartate transaminase activities, alkaline phosphatase activities and alanine aminotransferase activities. LBPs supplementation alleviated CCl 4 -induced liver fibrosis as demonstrated by reversing the above parameters. In addition, CCl 4 treatment induced the oxidative injury, increased the mRNA levels of tumor necrosis factor-α, monocyte chemoattractant protein-1 and interleukin-1β, and up-regulated the protein expressions of toll-like receptor 4 (TLR4), TLR2, myeloid differentiation factor 88, nuclear factor-kappa B (NF-kB) and p-p65. LBPs supplementation alleviated CCl 4 -induced oxidative injury, inflammatory response and TLRs/NF-kB signaling pathway expression by reversing the above some parameters. These results suggest that the alleviating effects of LBPs on CCl 4 -induced liver fibrosis in wistar rats may be through inhibiting the TLRs/NF-kB signaling pathway expression. Copyright © 2017 Elsevier Inc. All rights reserved.

Thrombin-induced, TNFR-dependent miR-181c downregulation promotes MLL1 and NF-κB target gene expression in human microglia.

Science.gov (United States)

Yin, Min; Chen, Zhiying; Ouyang, Yetong; Zhang, Huiyan; Wan, Zhigang; Wang, Han; Wu, Wei; Yin, Xiaoping

2017-06-29

Controlling thrombin-driven microglial activation may serve as a therapeutic target for intracerebral hemorrhage (ICH). Here, we investigated microRNA (miRNA)-based regulation of thrombin-driven microglial activation using an in vitro thrombin toxicity model applied to primary human microglia. A miRNA array identified 22 differential miRNA candidates. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) identified miR-181c as the most significantly downregulated miRNA. TargetScan analysis identified mixed lineage leukemia-1 (MLL1) as a putative gene target for miR-181c. qRT-PCR was applied to assess tumor necrosis factor-alpha (TNF-α), miR-181c, and MLL1 levels following thrombin or proteinase-activated receptor-4-specific activating peptide (PAR4AP) exposure. Anti-TNF-α antibodies and tumor necrosis factor receptor (TNFR) silencing were employed to test TNF-α/TNFR dependence. A dual-luciferase reporter system and miR-181c mimic transfection assessed whether mir-181c directly binds to and negatively regulates MLL1. Nuclear factor kappa-B (NF-κB)-dependent luciferase reporter assays and NF-κB target gene expression were assessed in wild-type (MLL1+) and MLL1-silenced cells. Thrombin or PAR4AP-induced miR-181c downregulation (p < 0.05) and MLL1 upregulation (p < 0.05) that were dependent upon TNF-α/TNFR. miR-181c decreased wild-type MLL1 3'-UTR luciferase reporter activity (p < 0.05), and a miR-181c mimic suppressed MLL1 expression (p < 0.05). Thrombin treatment increased, while miR-181c reduced, NF-κB activity and NF-κB target gene expression in both wild-type (MLL1+) and MLL1-silenced cells (p < 0.05). Thrombin-induced, TNF-α/TNFR-dependent miR-181c downregulation promotes MLL1 expression, increases NF-κB activity, and upregulates NF-κB target gene expression. As miR-181c opposes thrombin's stimulation of pro-inflammatory NF-κB activity, miR-181c mimic therapy may show promise in controlling thrombin

Wnt-11 signaling leads to down-regulation of the Wnt/β-catenin, JNK/AP-1 and NF-κB pathways and promotes viability in the CHO-K1 cells

International Nuclear Information System (INIS)

Railo, Antti; Nagy, Irina I.; Kilpelaeinen, Pekka; Vainio, Seppo

2008-01-01

The Wnt family of glycoprotein growth factors controls a number of central cellular processes such as proliferation, differentiation and ageing. All the Wnt proteins analyzed so far either activate or inhibit the canonical β-catenin signaling pathway that regulates transcription of the target genes. In addition, some of them activate noncanonical signaling pathways that involve components such as the JNK, heterotrimeric G proteins, protein kinase C, and calmodulin-dependent protein kinase II, although the precise signaling mechanisms are only just beginning to be revealed. We demonstrate here that Wnt-11 signaling is sufficient to inhibit not only the canonical β-catenin mediated Wnt signaling but also JNK/AP-1 and NF-κB signaling in the CHO cells, thus serving as a noncanonical Wnt ligand in this system. Inhibition of the JNK/AP-1 pathway is mediated in part by the MAPK kinase MKK4 and Akt. Moreover, protein kinase C is involved in the regulation of JNK/AP-1 by Wnt-11, but not of the NF-κB pathway. Consistent with the central role of Akt, JNK and NF-κB in cell survival and stress responses, Wnt-11 signaling promotes cell viability. Hence Wnt-11 is involved in coordination of key signaling pathways

NF-κB Protects NKT Cells from Tumor Necrosis Factor Receptor 1-induced Death.

Science.gov (United States)

Kumar, Amrendra; Gordy, Laura E; Bezbradica, Jelena S; Stanic, Aleksandar K; Hill, Timothy M; Boothby, Mark R; Van Kaer, Luc; Joyce, Sebastian

2017-11-15

Semi-invariant natural killer T (NKT) cells are innate-like lymphocytes with immunoregulatory properties. NKT cell survival during development requires signal processing by activated RelA/NF-κB. Nonetheless, the upstream signal(s) integrated by NF-κB in developing NKT cells remains incompletely defined. We show that the introgression of Bcl-x L -coding Bcl2l1 transgene into NF-κB signalling-deficient IκBΔN transgenic mouse rescues NKT cell development and differentiation in this mouse model. We reasoned that NF-κB activation was protecting developing NKT cells from death signals emanating either from high affinity agonist recognition by the T cell receptor (TCR) or from a death receptor, such as tumor necrosis factor receptor 1 (TNFR1) or Fas. Surprisingly, the single and combined deficiency in PKC-θ or CARMA-1-the two signal transducers at the NKT TCR proximal signalling node-only partially recapitulated the NKT cell deficiency observed in IκBΔN tg mouse. Accordingly, introgression of the Bcl2l1 transgene into PKC-θ null mouse failed to rescue NKT cell development. Instead, TNFR1-deficiency, but not the Fas-deficiency, rescued NKT cell development in IκBΔN tg mice. Consistent with this finding, treatment of thymocytes with an antagonist of the inhibitor of κB kinase -which blocks downstream NF-κB activation- sensitized NKT cells to TNF-α-induced cell death in vitro. Hence, we conclude that signal integration by NF-κB protects developing NKT cells from death signals emanating from TNFR1, but not from the NKT TCR or Fas.

Lycopene Inhibits NF-kB-Mediated IL-8 Expression and Changes Redox and PPARγ Signalling in Cigarette Smoke–Stimulated Macrophages

Science.gov (United States)

Simone, Rossella E.; Russo, Marco; Catalano, Assunta; Monego, Giovanni; Froehlich, Kati; Boehm, Volker; Palozza, Paola

2011-01-01

Increasing evidence suggests that lycopene, the major carotenoid present in tomato, may be preventive against smoke-induced cell damage. However, the mechanisms of such a prevention are still unclear. The aim of this study was to investigate the role of lycopene on the production of the pro-inflammatory cytokine IL-8 induced by cigarette smoke and the possible mechanisms implicated. Therefore, human THP-1 macrophages were exposed to cigarette smoke extract (CSE), alone and following a 6-h pre-treatment with lycopene (0.5–2 µM). CSE enhanced IL-8 production in a time- and a dose-dependent manner. Lycopene pre-treatment resulted in a significant inhibition of CSE-induced IL-8 expression at both mRNA and protein levels. NF-kB controlled the transcription of IL-8 induced by CSE, since PDTC prevented such a production. Lycopene suppressed CSE-induced NF-kB DNA binding, NF-kB/p65 nuclear translocation and phosphorylation of IKKα and IkBα. Such an inhibition was accompanied by a decrease in CSE-induced ROS production and NOX-4 expression. Lycopene further inhibited CSE-induced phosphorylation of the redox-sensitive ERK1/2, JNK and p38 MAPKs. Moreover, the carotenoid increased PPARγ levels which, in turn, enhanced PTEN expression and decreased pAKT levels in CSE-exposed cells. Such effects were abolished by the PPARγ inhibitor GW9662. Taken together, our data indicate that lycopene prevented CSE-induced IL-8 production through a mechanism involving an inactivation of NF-kB. NF-kB inactivation was accompanied by an inhibition of redox signalling and an activation of PPARγ signalling. The ability of lycopene in inhibiting IL-8 production, NF-kB/p65 nuclear translocation, and redox signalling and in increasing PPARγ expression was also found in isolated rat alveolar macrophages exposed to CSE. These findings provide novel data on new molecular mechanisms by which lycopene regulates cigarette smoke-driven inflammation in human macrophages. PMID:21625550

Using High-Precision Signaling Activity Imaging to Personalize Ras Pathway Inhibition Strategies in Neurofibromatosis

Science.gov (United States)

2017-06-01

cell types and genetic contexts relevant to NF1. During this award period, we have improved methodologies for introducing genetically encoded...shown that the kinetics of ERK and Akt activation, including the intensity, duration, and probability of response, are critical for deciding how the...and genetic configurations relevant to NF1. We will assess whether NF1 mutants cells differ in signaling intensity, duration, threshold, or basal

Eggshell membrane hydrolyzates activate NF-κB in vitro: possible implications for in vivo efficacy

Directory of Open Access Journals (Sweden)

Ruff KJ

2015-02-01

Full Text Available Kevin J Ruff,1 Paul L Durham,2 Austin O’Reilly,2 F Daniel Long1 1ESM Technologies, LLC, Carthage, MO, USA; 2Center for Biomedical and Life Sciences, Missouri State University, Springfield, MO, USA Purpose: Eggshell membrane (ESM has been shown to contain naturally occurring bioactive components, and biological activities such as reducing proinflammatory cytokines, liver fibrosis, and joint pain in osteoarthritis sufferers have also been reported for ESM matrix as a whole. Nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB is a signaling protein found in the cytoplasm of nearly all human and animal cell types and is a primary regulator of immune function. The studies reported herein were designed to investigate the possible role that NF-κB activity might play in the reported biological activities of ESM. Methods: Three ESM hydrolyzates produced via fermentation, enzymatic, or chemical hydrolysis were evaluated in vitro in either human peripheral blood mononuclear cell or THP-1 (human leukemic monocyte cell cultures for NF-κB activity following 4-hour exposure. The hydrolyzates were compared with untreated control cells or cells incubated with lipopolysaccharide or ascorbic acid. The source of ESM activity was also evaluated. Results: NF-κB levels were increased above levels found in untreated cells at all three dilutions (1:100, 1:1,000, and 1:10,000 for the fermentation hydrolyzate of ESM (ESM-FH (P=0.021, P=0.020, P=0.009, respectively in peripheral blood mononuclear cells. The enzymatic hydrolyzate of ESM (ESM-EH also produced statistically significant levels of activated NF-κB at the 1:100 and 1:1,000 dilutions (P=0.004, P=0.006, respectively but fell just shy of significance at the 1:10,000 dilution (P=0.073. Similarly, ESM-FH (P=0.021, P=0.002 and ESM-EH (P=0.007, P=0.007 activated NF-κB in THP-1 cells at 1:1,000 and 1:10,000 dilutions, respectively. The chemical hydrolyzate of ESM (ESM-CH showed statistically

6-OHDA-induced apoptosis and mitochondrial dysfunction are mediated by early modulation of intracellular signals and interaction of Nrf2 and NF-κB factors

International Nuclear Information System (INIS)

Tobón-Velasco, Julio C.; Limón-Pacheco, Jorge H.; Orozco-Ibarra, Marisol; Macías-Silva, Marina; Vázquez-Victorio, Genaro; Cuevas, Elvis; Ali, Syed F.

2013-01-01

6-Hydroxydopamine (6-OHDA) is a neurotoxin that generates an experimental model of Parkinson's disease in rodents and is commonly employed to induce a lesion in dopaminergic pathways. The characterization of those molecular mechanisms linked to 6-OHDA-induced early toxicity is needed to better understand the cellular events further leading to neurodegeneration. The present work explored how 6-OHDA triggers early downstream signaling pathways that activate neurotoxicity in the rat striatum. Mitochondrial function, caspases-dependent apoptosis, kinases signaling (Akt, ERK 1/2, SAP/JNK and p38) and crosstalk between nuclear factor kappa B (NF-κB) and nuclear factor-erythroid-2-related factor 2 (Nrf2) were evaluated at early times post-lesion. We found that 6-OHDA initiates cell damage via mitochondrial complex I inhibition, cytochrome c and apoptosis-inducing factor (AIF) release, as well as activation of caspases 9 and 3 to induce apoptosis, kinase signaling modulation and NF-κB-mediated inflammatory responses, accompanied by inhibition of antioxidant systems regulated by the Nrf2 pathway. Our results suggest that kinases SAP/JNK and p38 up-regulation may play a role in the early stages of 6-OHDA toxicity to trigger intrinsic pathways for apoptosis and enhanced NF-κB activation. In turn, these cellular events inhibit the activation of cytoprotective mechanisms, thereby leading to a condition of general damage

Modulation of NF-KB in rescued irradiated cells

International Nuclear Information System (INIS)

Lam, R.K.K.; Fung, Y.K.; Han, W.; Li, L.; Chiu, S.K.; Cheng, S.H.; Yu, K.N.

2015-01-01

Studies by different groups on the rescue effect, where unirradiated bystander cells mitigated the damages in the irradiated cells, since its discovery by the authors' group in 2011 were first reviewed. The properties of the rescue effect were then examined using a novel experimental set-up to physically separate the rescue signals from the bystander signals. The authors' results showed that the rescue effect was mediated through activation of the nuclear factor-KB (NF-KB) response pathway in the irradiated cells, and that the NF-KB activation inhibitor BAy -1 1-7082 did not affect the activation of this response pathway in the irradiated cells induced by direct irradiation. (authors)

Targeting NF-kB signaling with polymeric hybrid micelles that co-deliver siRNA and dexamethasone for arthritis therapy.

Science.gov (United States)

Wang, Qin; Jiang, Hao; Li, Yan; Chen, Wenfei; Li, Hanmei; Peng, Ke; Zhang, Zhirong; Sun, Xun

2017-04-01

The transcription factor NF-kB plays a pivotal role in the pathogenesis of rheumatoid arthritis. Here we attempt to slow arthritis progression by co-delivering the glucocorticoid dexamethasone (Dex) and small-interfering RNA targeting NF-kB p65 using our previously developed polymeric hybrid micelle system. These micelles contain two similar amphiphilic copolymers: polycaprolactone-polyethylenimine (PCL-PEI) and polycaprolactone-polyethyleneglycol (PCL-PEG). The hybrid micelles loaded with Dex and siRNA effectively inhibited NF-kB signaling in murine macrophages more efficiently than micelles containing either Dex or siRNA on their own. In addition, the co-delivery system was able to switch macrophages from the M1 to M2 state. Injecting hybrid micelles containing Dex and siRNA into mice with collagen-induced arthritis led the therapeutic agents to accumulate in inflamed joints and reduce inflammation, without damaging renal or liver function. Thus, blocking NF-kB activation in inflammatory tissue using micelle-based co-delivery may provide a new approach for treating inflammatory disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Diclofenac inhibits tumor necrosis factor-α-induced nuclear factor-κB activation causing synergistic hepatocyte apoptosis.

Science.gov (United States)

Fredriksson, Lisa; Herpers, Bram; Benedetti, Giulia; Matadin, Quraisha; Puigvert, Jordi C; de Bont, Hans; Dragovic, Sanja; Vermeulen, Nico P E; Commandeur, Jan N M; Danen, Erik; de Graauw, Marjo; van de Water, Bob

2011-06-01

Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by diclofenac and the proinflammatory cytokine tumor necrosis factor α (TNF-α). HepG2 cells were treated with diclofenac followed by TNF-α challenge and subsequent evaluation of necrosis and apoptosis. Diclofenac caused a mild apoptosis of HepG2 cells, which was strongly potentiated by TNF-α. A focused apoptosis machinery short interference RNA (siRNA) library screen identified that this TNF-α-mediated enhancement involved activation of caspase-3 through a caspase-8/Bid/APAF1 pathway. Diclofenac itself induced sustained activation of c-Jun N-terminal kinase (JNK) and inhibition of JNK decreased both diclofenac and diclofenac/TNF-α-induced apoptosis. Live cell imaging of GFPp65/RelA showed that diclofenac dampened the TNF-α-mediated nuclear factor kappaB (NF-κB) translocation oscillation in association with reduced NF-κB transcriptional activity. This was associated with inhibition by diclofenac of the TNF-α-induced phosphorylation of the inhibitor of NF-κB alpha (IκBα). Finally, inhibition of IκB kinase β (IKKβ) with BMS-345541 as well as stable lentiviral short hairpin RNA (shRNA)-based knockdown of p65/RelA sensitized hepatocytes towards diclofenac/TNF-α-induced cytotoxicity. Together, our data suggest a model whereby diclofenac-mediated stress signaling suppresses TNF-α-induced survival signaling routes and sensitizes cells to apoptosis. Copyright © 2011 American Association for the Study of Liver Diseases.

Estrogen deficiency inhibits the odonto/osteogenic differentiation of dental pulp stem cells via activation of the NF-κB pathway.

Science.gov (United States)

Wang, Yanping; Yan, Ming; Yu, Yan; Wu, Jintao; Yu, Jinhua; Fan, Zhipeng

2013-06-01

Various factors can affect the functions of dental pulp stem cells (DPSCs). However, little knowledge is available about the effects of estrogen deficiency on the differentiation of DPSCs. In this study, an estrogen-deficient rat model was constructed and multi-colony-derived DPSCs were obtained from the incisors of ovariectomized (OVX) or sham-operated rats. Odonto/osteogenic differentiation and the possible involvement of the nuclear factor kappa B (NF-κB) pathway in the OVX-DPSCs/Sham-DPSCs of these rats were then investigated. OVX-DPSCs presented decreased odonto/osteogenic capacity and an activated NF-κB pathway, as compared with Sham-DPSCs. When the cellular NF-κB pathway was specifically inhibited by BMS345541, the odonto/osteogenic potential in OVX-DPSCs was significantly upregulated. Thus, estrogen deficiency down-regulated the odonto/osteogenic differentiation of DPSCs by activating NF-κB signaling and inhibition of the NF-κB pathway effectively rescued the decreased differentiation potential of DPSCs.

Recombinant Human Endostatin Suppresses Mouse Osteoclast Formation by Inhibiting the NF-κB and MAPKs Signaling Pathways

Directory of Open Access Journals (Sweden)

Non eChen

2016-06-01

Full Text Available Rheumatoid arthritis is an autoimmune disease characterized by synovial hyperplasia and progressive joint destruction. As reported previously, recombinant human endostatin (rhEndostatin is associated with inhibition of joint bone destruction present in rat adjuvant-induced arthritis; however, the effect of rhEndostatin on bone destruction is not known. This study was designed to assess the inhibitory effect and mechanisms of rhEndostatin on formation and function of osteoclasts in vitro, and to gain insight into the mechanism underlying the inhibitory effect of bone destruction. Bone marrow-derived macrophages isolated from BALB/c mice were stimulated with receptor activator of NF-κB ligand (RANKL and macrophage colony-stimulating factor to establish osteoclast formation. Osteoclast formation was determined by TRAP staining. Cell viability of BMMs affected by rhEndostatin was determined using a MTT assay. Bone resorption was examined with a bone resorption pits assay. The expression of osteoclast-specific markers was analyzed using quantitative real-time PCR. The related signaling pathways were examined using a Luciferase reporter assay and western blot analysis. Indeed, rhEndostatin showed a significant reduction in the number of osteoclast-like cells and early-stage bone resorption. Moreover, molecular analysis demonstrated that rhEndostatin attenuated RANKL-induced NF-κB signaling by inhibiting the phosphorylation of IκBα and NF-κB p65 nuclear translocation. Furthermore, rhEndostatin significantly inhibited the activation of RANKL-dependent mitogen-activated protein kinases (MAPKs, such as ERK1/2, JNK, and p38. Hence, we demonstrated for the first time that preventing the formation and function of osteoclasts is an important anti-bone destruction mechanism of rhEndostatin, which might be useful in the prevention and treatment of bone destruction in RA.

DNA-dependent protein kinase participates in the radiation activation of NF-kB

International Nuclear Information System (INIS)

Rosenzweig, Kenneth E.; Youmell, Matthew B.; Price, Brendan D.

1997-01-01

The NF-kB transcription factor is maintained in an inactive state by binding to the lkBa inhibitory protein. Activation requires phosphorylation and degradation of lkBa, releasing active NF-kB. NF-kB can be activated by cytokines, antigens, free radicals and X-ray irradiation. The protein kinase responsible for phosphorylation of lkBa in vivo has not been fully characterized. Here, we have examined the role of the DNA-dependent protein kinases (DNA-PK) in the radiation-activation of NF-kB. Wortmannin is an inhibitor of DNA-PK and related kinases. Exposure of SW480 cells to wortmannin inhibited the radioactivation of NF-kB DNA-binding. Analysis of lkBa levels by western blotting indicated that wortmannin blocked the radiation induced degradation of lkBa. In in vitro experiments, purified DNA-PK was able to efficiently phosphorylate lkBa, and this phosphorylation was inhibited by wortmannin. In contrast, the induction of NF-kB activity by TNFa was unaffected by wortmannin. The results suggest that DNA-PK may phosphorylate lkBa following irradiation, leading to degradation of lkBa and the release of active NF-kB. The inability of wortmannin to block TNFa activation of NF-kB indicates there may be more than one pathway for the activation of NF-kB

Morin impedes Yap nuclear translocation and fosters apoptosis through suppression of Wnt/β-catenin and NF-κB signaling in Mst1 overexpressed HepG2 cells

Energy Technology Data Exchange (ETDEWEB)

Perumal, NaveenKumar [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Perumal, MadanKumar [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States); Kannan, Anbarasu [Department of Cellular and Molecular Biology, The University of Texas Health Science Center, Tyler, Texas (United States); Subramani, Kumar [Centre for Biotechnology, Anna University, Chennai 600025, Tamil Nadu (India); Halagowder, Devaraj [Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Sivasithamparam, NiranjaliDevaraj, E-mail: profniranjali@gmail.com [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India)

2017-06-15

Recent clinical and experimental evidences strongly acclaim Yes-associated protein (Yap), a key oncogenic driver in liver carcinogenesis, as a therapeutic target. Of the known multiple schemes to inhibit Yap activity, activation of Mammalian Sterile 20-like Kinase 1 (Mst1), an upstream regulator of Yap, appears to be a promising one. In this study, we hypothesize that morin, a bioflavonoid, mediates its anti-cancer effect through the activation of Mst1/hippo signaling in liver cancer cells. To test this hypothesis, both full length Mst1 (F-Mst1) and kinase active N-terminal Mst1 (N-Mst1)-overexpressed HepG2 cells were used. Exposure of F-Mst1 overexpressed HepG2 cells to morin activated Mst1 by caspase-3 cleavage and thereby inhibited Yap nuclear translocation and fostered apoptosis. Morin suppressed NF-κB p65 and Wnt/β-catenin signaling through Mst1 activation via cleavage and phosphorylation, leading to cell death. Annexin-V/PI staining further confirmed the induction of apoptosis in morin treated F-Mst1 overexpressed cells. The present study shows that morin targets cell survival molecules such as NF-κB p65 and β-catenin through activation of hippo signaling. Therefore, morin could be considered as a potential anti-cancer agent against liver cancer. - Highlights: • Morin induced cytotoxicity in cultured HepG2 cells. • Morin activated hippo pathway via Mst1 activation in transfected HepG2 cells. • Morin suppressed Wnt/β-catenin signaling and induced G0/G1 cell cycle arrest. • Morin inhibited NF-κB signaling through Mst1 activation in transfected HepG2 cells. • Morin potentiates apoptosis through Mst1-JNK-caspase mediated mechanism in HepG2 cells.

Morin impedes Yap nuclear translocation and fosters apoptosis through suppression of Wnt/β-catenin and NF-κB signaling in Mst1 overexpressed HepG2 cells

International Nuclear Information System (INIS)

Perumal, NaveenKumar; Perumal, MadanKumar; Kannan, Anbarasu; Subramani, Kumar; Halagowder, Devaraj; Sivasithamparam, NiranjaliDevaraj

2017-01-01

Recent clinical and experimental evidences strongly acclaim Yes-associated protein (Yap), a key oncogenic driver in liver carcinogenesis, as a therapeutic target. Of the known multiple schemes to inhibit Yap activity, activation of Mammalian Sterile 20-like Kinase 1 (Mst1), an upstream regulator of Yap, appears to be a promising one. In this study, we hypothesize that morin, a bioflavonoid, mediates its anti-cancer effect through the activation of Mst1/hippo signaling in liver cancer cells. To test this hypothesis, both full length Mst1 (F-Mst1) and kinase active N-terminal Mst1 (N-Mst1)-overexpressed HepG2 cells were used. Exposure of F-Mst1 overexpressed HepG2 cells to morin activated Mst1 by caspase-3 cleavage and thereby inhibited Yap nuclear translocation and fostered apoptosis. Morin suppressed NF-κB p65 and Wnt/β-catenin signaling through Mst1 activation via cleavage and phosphorylation, leading to cell death. Annexin-V/PI staining further confirmed the induction of apoptosis in morin treated F-Mst1 overexpressed cells. The present study shows that morin targets cell survival molecules such as NF-κB p65 and β-catenin through activation of hippo signaling. Therefore, morin could be considered as a potential anti-cancer agent against liver cancer. - Highlights: • Morin induced cytotoxicity in cultured HepG2 cells. • Morin activated hippo pathway via Mst1 activation in transfected HepG2 cells. • Morin suppressed Wnt/β-catenin signaling and induced G0/G1 cell cycle arrest. • Morin inhibited NF-κB signaling through Mst1 activation in transfected HepG2 cells. • Morin potentiates apoptosis through Mst1-JNK-caspase mediated mechanism in HepG2 cells.

Classical NF-κB Metabolically Reprograms Sarcoma Cells Through Regulation of Hexokinase 2

Directory of Open Access Journals (Sweden)

Priya Londhe

2018-04-01

Full Text Available BackgroundMetabolic reprogramming has emerged as a cancer hallmark, and one of the well-known cancer-associated metabolic alterations is the increase in the rate of glycolysis. Recent reports have shown that both the classical and alternative signaling pathways of nuclear factor κB (NF-κB play important roles in controlling the metabolic profiles of normal cells and cancer cells. However, how these signaling pathways affect the metabolism of sarcomas, specifically rhabdomyosarcoma (RMS and osteosarcoma (OS, has not been characterized.MethodsClassical NF-κB activity was inhibited through overexpression of the IκBα super repressor of NF-κB in RMS and OS cells. Global gene expression analysis was performed using Affymetrix GeneChip Human Transcriptome Array 2.0, and data were interpreted using gene set enrichment analysis. Seahorse Bioscience XFe24 was used to analyze oxygen consumption rate as a measure of aerobic respiration.ResultsInhibition of classical NF-κB activity in sarcoma cell lines restored alternative signaling as well as an increased oxidative respiratory metabolic phenotype in vitro. In addition, microarray analysis indicated that inhibition of NF-κB in sarcoma cells reduced glycolysis. We showed that a glycolytic gene, hexokinase (HK 2, is a direct NF-κB transcriptional target. Knockdown of HK2 shifted the metabolic profile in sarcoma cells away from aerobic glycolysis, and re-expression of HK2 rescued the metabolic shift induced by inhibition of NF-κB activity in OS cells.ConclusionThese findings suggest that classical signaling of NF-κB plays a crucial role in the metabolic profile of pediatric sarcomas potentially through the regulation of HK2.

Novel Serine 176 Phosphorylation of YBX1 Activates NF-κB in Colon Cancer.

Science.gov (United States)

Martin, Matthew; Hua, Laiqing; Wang, Benlian; Wei, Han; Prabhu, Lakshmi; Hartley, Antja-Voy; Jiang, Guanglong; Liu, Yunlong; Lu, Tao

2017-02-24

Y box protein 1 (YBX1) is a well known oncoprotein that has tumor-promoting functions. YBX1 is widely considered to be an attractive therapeutic target in cancer. To develop novel therapeutics to target YBX1, it is of great importance to understand how YBX1 is finely regulated in cancer. Previously, we have shown that YBX1 could function as a tumor promoter through phosphorylation of its Ser-165 residue, leading to the activation of the NF-κB signaling pathway (1). In this study, using mass spectrometry analysis, we discovered a distinct phosphorylation site, Ser-176, on YBX1. Overexpression of the YBX1-S176A (serine-to-alanine) mutant in either HEK293 cells or colon cancer HT29 cells showed dramatically reduced NF-κB-activating ability compared with that of WT-YBX1, confirming that Ser-176 phosphorylation is critical for the activation of NF-κB by YBX1. Importantly, the mutant of Ser-176 and the previously reported Ser-165 sites regulate distinct groups of NF-κB target genes, suggesting the unique and irreplaceable function of each of these two phosphorylated serine residues. Our important findings could provide a novel cancer therapy strategy by blocking either Ser-176 or Ser-165 phosphorylation or both of YBX1 in colon cancer. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Targeting of NF-κB to Dendritic Spines Is Required for Synaptic Signaling and Spine Development.

Science.gov (United States)

Dresselhaus, Erica C; Boersma, Matthew C H; Meffert, Mollie K

2018-04-25

Long-term forms of brain plasticity share a requirement for changes in gene expression induced by neuronal activity. Mechanisms that determine how the distinct and overlapping functions of multiple activity-responsive transcription factors, including nuclear factor κB (NF-κB), give rise to stimulus-appropriate neuronal responses remain unclear. We report that the p65/RelA subunit of NF-κB confers subcellular enrichment at neuronal dendritic spines and engineer a p65 mutant that lacks spine enrichment (p65ΔSE) but retains inherent transcriptional activity equivalent to wild-type p65. Wild-type p65 or p65ΔSE both rescue NF-κB-dependent gene expression in p65-deficient murine hippocampal neurons responding to diffuse (PMA/ionomycin) stimulation. In contrast, neurons lacking spine-enriched NF-κB are selectively impaired in NF-κB-dependent gene expression induced by elevated excitatory synaptic stimulation (bicuculline or glycine). We used the setting of excitatory synaptic activity during development that produces NF-κB-dependent growth of dendritic spines to test physiological function of spine-enriched NF-κB in an activity-dependent response. Expression of wild-type p65, but not p65ΔSE, is capable of rescuing spine density to normal levels in p65-deficient pyramidal neurons. Collectively, these data reveal that spatial localization in dendritic spines contributes unique capacities to the NF-κB transcription factor in synaptic activity-dependent responses. SIGNIFICANCE STATEMENT Extensive research has established a model in which the regulation of neuronal gene expression enables enduring forms of plasticity and learning. However, mechanisms imparting stimulus specificity to gene regulation, ensuring biologically appropriate responses, remain incompletely understood. NF-κB is a potent transcription factor with evolutionarily conserved functions in learning and the growth of excitatory synaptic contacts. Neuronal NF-κB is localized in both synapse and

Heterologous SUMO-2/3-ubiquitin chains optimize IκBα degradation and NF-κB activity.

Directory of Open Access Journals (Sweden)

Fabienne Aillet

Full Text Available The NF-κB pathway is regulated by SUMOylation at least at three levels: the inhibitory molecule IκBα, the IKK subunit γ/NEMO and the p52 precursor p100. Here we investigate the role of SUMO-2/3 in the degradation of IκBα and activation of NF-κB mediated by TNFα. We found that under conditions of deficient SUMOylation, an important delay in both TNFα-mediated proteolysis of IκBα and NF-κB dependent transcription occurs. In vitro and ex vivo approaches, including the use of ubiquitin-traps (TUBEs, revealed the formation of chains on IκBα containing SUMO-2/3 and ubiquitin after TNFα stimulation. The integration of SUMO-2/3 appears to promote the formation of ubiquitin chains on IκBα after activation of the TNFα signalling pathway. Furthermore, heterologous chains of SUMO-2/3 and ubiquitin promote a more efficient degradation of IκBα by the 26S proteasome in vitro compared to chains of either SUMO-2/3 or ubiquitin alone. Consistently, Ubc9 silencing reduced the capture of IκBα modified with SUMO-ubiquitin hybrid chains that display a defective proteasome-mediated degradation. Thus, hybrid SUMO-2/3-ubiquitin chains increase the susceptibility of modified IκBα to the action of 26S proteasome, contributing to the optimal control of NF-κB activity after TNFα-stimulation.

Acetylshikonin Inhibits Human Pancreatic PANC-1 Cancer Cell Proliferation by Suppressing the NF-κB Activity.

Science.gov (United States)

Cho, Seok-Cheol; Choi, Bu Young

2015-09-01

Acetylshikonin, a natural naphthoquinone derivative compound, has been used for treatment of inflammation and cancer. In the present study, we have investigated whether acetylshikonin could regulate the NF-κB signaling pathway, thereby leading to suppression of tumorigenesis. We observed that acetylshikonin significantly reduced proliferation of several cancer cell lines, including human pancreatic PANC-1 cancer cells. In addition, acetylshikonin inhibited phorbol 12-myristate 13-acetate (PMA) or tumor necrosis-α (TNF-α)-induced NF-κB reporter activity. Proteome cytokine array and real-time RT-PCR results illustrated that acetylshikonin inhibition of PMA-induced production of cytokines was mediated at the transcriptional level and it was associated with suppression of NF-κB activity and matrix metalloprotenases. Finally, we observed that an exposure of acetylshikonin significantly inhibited the anchorage-independent growth of PANC-1 cells. Together, our results indicate that acetylshikonin could serve as a promising therapeutic agent for future treatment of pancreatic cancer.

Loss of the HPV-infection resistance EVER2 protein impairs NF-κB signaling pathways in keratinocytes.

Directory of Open Access Journals (Sweden)

Françoise Vuillier

Full Text Available Homozygous mutations in EVER genes cause epidermodysplasia verruciformis (EV, characterized by an immune defect and the development of skin cancers associated with β-human papillomavirus (HPV infections. The effects of EVER protein loss on the keratinocyte immune response remain unknown. We show here that EVER2 plays a critical role in the interplay between the NF-κB and JNK/AP-1 signaling pathways. EVER2-deficient cells overproduce IL-6 following the upregulation of JNK activation. They respond poorly to phorbol ester and TNF via the NF-κB pathway. They have lower levels of IKKα subunit, potentially accounting for impairments of p100 processing and the alternative NF-κB pathway. The loss of EVER2 is associated with an unusual TRAF protein profile. We demonstrate that EVER2 deficiency sustains TRAF2 ubiquitination and decreases the pool of TRAF2 available in the detergent-soluble fraction of the cell. Finally, we demonstrate that EVER2 loss induces constitutive PKCα-dependent c-jun phosphorylation and facilitates activation of the HPV5 long control region through a JNK-dependent pathway. These findings indicate that defects of the EVER2 gene may create an environment conducive to HPV replication and the persistence of lesions with the potential to develop into skin cancer.

NF-κB in T-cell Acute Lymphoblastic Leukemia: Oncogenic Functions in Leukemic and in Microenvironmental Cells

International Nuclear Information System (INIS)

Santos, Nuno R. dos; Ghezzo, Marinella N.; Silva, Ricardo C. da; Fernandes, Mónica T.

2010-01-01

Two main NF-κB signaling pathways, canonical and noncanonical, performing distinct functions in organisms have been characterized. Identification of mutations in genes encoding components of these NF-κB signaling pathways in lymphoid malignancies confirmed their key role in leukemogenesis. T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes that despite significant therapeutic advances can still be fatal. Although mutations in NF-κB genes have not been reported in T-ALL, NF-κB constitutive activation in human T-ALL and in acute T-cell leukemia mouse models has been observed. Although these studies revealed activation of members of both canonical and noncanonical NF-κB pathways in acute T-cell leukemia, only inhibition of canonical NF-κB signaling was shown to impair leukemic T cell growth. Besides playing an important pro-oncogenic role in leukemic T cells, NF-κB signaling also appears to modulate T-cell leukemogenesis through its action in microenvironmental stromal cells. This article reviews recent data on the role of these transcription factors in T-ALL and pinpoints further research crucial to determine the value of NF-κB inhibition as a means to treat T-ALL

NF-κB in T-cell Acute Lymphoblastic Leukemia: Oncogenic Functions in Leukemic and in Microenvironmental Cells

Energy Technology Data Exchange (ETDEWEB)

Santos, Nuno R. dos, E-mail: nrsantos@ualg.pt; Ghezzo, Marinella N.; Silva, Ricardo C. da; Fernandes, Mónica T. [IBB-Institute for Biotechnology and Bioengineering, Centre for Molecular and Structural Biomedicine (CBME), University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

2010-11-05

Two main NF-κB signaling pathways, canonical and noncanonical, performing distinct functions in organisms have been characterized. Identification of mutations in genes encoding components of these NF-κB signaling pathways in lymphoid malignancies confirmed their key role in leukemogenesis. T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes that despite significant therapeutic advances can still be fatal. Although mutations in NF-κB genes have not been reported in T-ALL, NF-κB constitutive activation in human T-ALL and in acute T-cell leukemia mouse models has been observed. Although these studies revealed activation of members of both canonical and noncanonical NF-κB pathways in acute T-cell leukemia, only inhibition of canonical NF-κB signaling was shown to impair leukemic T cell growth. Besides playing an important pro-oncogenic role in leukemic T cells, NF-κB signaling also appears to modulate T-cell leukemogenesis through its action in microenvironmental stromal cells. This article reviews recent data on the role of these transcription factors in T-ALL and pinpoints further research crucial to determine the value of NF-κB inhibition as a means to treat T-ALL.

Diphlorethohydroxycarmalol from Ishige okamurae Suppresses Osteoclast Differentiation by Downregulating the NF-κB Signaling Pathway

Directory of Open Access Journals (Sweden)

Hye Jung Ihn

2017-12-01

Full Text Available Marine algae possess a variety of beneficial effects on human health. In this study, we investigated whether diphlorethohydroxycarmalol (DPHC, isolated from Ishige okamurae, a brown alga, suppresses receptor activator of nuclear factor-κB ligand (RANKL-induced osteoclast differentiation. DPHC significantly suppressed RANKL-induced osteoclast differentiation and macrophage-colony stimulating factor (M-CSF expression in a dose-dependent manner. In addition, it significantly inhibited actin ring formation, the expression of osteoclast marker genes, such as tartrate-resistant acid phosphatase (TRAP, nuclear factor of activated T-cells cytoplasmic 1 (Nfatc1, cathepsin K (Ctsk, and dendritic cell-specific transmembrane protein (Dcstamp, and osteoclast-induced bone resorption. Analysis of the RANKL-mediated signaling pathway showed that the phosphorylation of both IκB and p65 was specifically inhibited by DPHC. These results suggest that DPHC substantially suppresses osteoclastogenesis by downregulating the RANK-NF-κB signaling pathway. Thus, it holds significant potential for the treatment of skeletal diseases associated with an enhanced osteoclast activity.

Transcription Factor NF-κB: An Update on Intervention Strategies.

Science.gov (United States)

Panday, Arvind; Inda, Maria Eugenia; Bagam, Prathyusha; Sahoo, Malaya K; Osorio, Diana; Batra, Sanjay

2016-12-01

The nuclear factor (NF)-κB family of transcription factors are ubiquitous and pleiotropic molecules that regulate the expression of more than 150 genes involved in a broad range of processes including inflammation, immunity, cell proliferation, differentiation, and survival. The chronic activation or dysregulation of NF-κB signaling is the central cause of pathogenesis in many disease conditions and, therefore, NF-κB is a major focus of therapeutic intervention. Because of this, understanding the relationship between NF-κB and the induction of various downstream signaling molecules is imperative. In this review, we provide an updated synopsis of the role of NF-κB in DNA repair and in various ailments including cardiovascular diseases, HIV infection, asthma, herpes simplex virus infection, chronic obstructive pulmonary disease, and cancer. Furthermore, we also discuss the specific targets for selective inhibitors and future therapeutic strategies.

Melatonin alleviates inflammasome-induced pyroptosis through inhibiting NF-κB/GSDMD signal in mice adipose tissue.

Science.gov (United States)

Liu, Zhenjiang; Gan, Lu; Xu, Yatao; Luo, Dan; Ren, Qian; Wu, Song; Sun, Chao

2017-08-01

Pyroptosis is a proinflammatory form of cell death that is associated with pathogenesis of many chronic inflammatory diseases. Melatonin is substantially reported to possess anti-inflammatory properties by inhibiting inflammasome activation. However, the effects of melatonin on inflammasome-induced pyroptosis in adipocytes remain elusive. Here, we demonstrated that melatonin alleviated lipopolysaccharides (LPS)-induced inflammation and NLRP3 inflammasome formation in mice adipose tissue. The NLRP3 inflammasome-mediated pyroptosis was also inhibited by melatonin in adipocytes. Further analysis revealed that gasdermin D (GSDMD), the key executioner of pyroptosis, was the target for melatonin inhibition of adipocyte pyroptosis. Importantly, we determined that nuclear factor κB (NF-κB) signal was required for the GSDMD-mediated pyroptosis in adipocytes. We also confirmed that melatonin alleviated adipocyte pyroptosis by transcriptional suppression of GSDMD. Moreover, GSDMD physically interacted with interferon regulatory factor 7 (IRF7) and subsequently formed a complex to promote adipocyte pyroptosis. Melatonin also attenuated NLRP3 inflammasome activation and pyroptosis, which was induced by LPS or obesity. In summary, our results demonstrate that melatonin alleviates inflammasome-induced pyroptosis by blocking NF-κB/GSDMD signal in mice adipose tissue. Our data reveal a novel function of melatonin on adipocyte pyroptosis, suggesting a new potential therapy for melatonin to prevent and treat obesity caused systemic inflammatory response. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Phorbol-ester-induced activation of the NF-κB transcription factor involves dissociation of an apparently cytoplasmic NF-κB/inhibitor complex

International Nuclear Information System (INIS)

Baeuerle, P.A.; Lenardo, M.; Pierce, J.W.; Baltimore, D.

1988-01-01

There is increasing evidence that inducible transcription of genes is mediated through the induction of the activity of trans-acting protein factors. The NF-κB transcription factor provides a model system to study the posttranslational activation of a phorbol-ester-inducible transcription factor. The finding that NF-κB activity is undectable in subcellular fractions from unstimulated cells suggests that NF-κB exists as an inactive precursor. The authors showed that NF-κB is detectable in two different forms. After selective removal of endogenous NF-κB, they demonstrate the existence of a protein inhibitor in cytosolic fractions of unstimulated cells that is able in vitro to convert NF-κB into an inactive desoxycholate-dependent form. The data are consistent with a molecular mechanism of inducible gene expression by which an apparently cytoplasmic transcription factor-inhibitor complex is dissociated by the action of TPA-activated protein kinase C

Cell wall mannoprotein of Candida albicans induces cell cycle alternation and inhibits apoptosis of HaCaT cells via NF-κB signal pathway.

Science.gov (United States)

Han, Yang; Jiang, Hang-Hang; Zhang, Yu-Jing; Hao, Xing-Jia; Sun, Yu-Zhe; Qi, Rui-Qun; Chen, Hong-Duo; Gao, Xing-Hua

2017-10-01

Candida albicans (C. albicans) is a commensal organism in human and a well-known dimorphic opportunistic pathogenic fungus. Though plenty of researches on the pathogenesis of C. albicans have been performed, the mechanism is not fully understood. The cell wall components of C. albicans have been documented to play important roles in its pathogenic processes. To further study the infectious mechanism of C. albicans, we investigated the potential functional role of its cell wall mannoprotein in cell cycle and apoptosis of HaCaT cells. We found that mannoprotein could promote the transition of cell cycle from G1/G0 to S phase, in which Cyclin D1, CDK4 and p-Rb, the major regulators of the cell cycle progression, showed significant upregulation, and CDKN1A (cyclin dependent kinase inhibitor 1A (p21)) showed significant downregulation. Mannoprotein also could inhibit apoptosis of HaCaT cells, which was well associated with increased expression of BCL2 (Bcl-2). Moreover, mannoprotein could increase the phosphorylation levels of RELA (p65) and NFKBIA (IκBα), as the key factors of NF-κB signal pathway in HaCaT cells, suggesting the activation of NF-κB signal pathway. Additionally, a NF-κB specific inhibitor, PDTC, could rescue the effect of mannoprotein on cell cycle and apoptosis of HaCaT cells, which suggested that mannoprotein could activate NF-κB signal pathway to mediate cell cycle alternation and inhibit apoptosis. Copyright © 2017. Published by Elsevier Ltd.

SseK3 Is a Salmonella Effector That Binds TRIM32 and Modulates the Host's NF-κB Signalling Activity.

Directory of Open Access Journals (Sweden)

Zhe Yang

Full Text Available Salmonella Typhimurium employs an array of type III secretion system effectors that facilitate intracellular survival and replication during infection. The Salmonella effector SseK3 was originally identified due to amino acid sequence similarity with NleB; an effector secreted by EPEC/EHEC that possesses N-acetylglucoasmine (GlcNAc transferase activity and modifies death domain containing proteins to block extrinsic apoptosis. In this study, immunoprecipitation of SseK3 defined a novel molecular interaction between SseK3 and the host protein, TRIM32, an E3 ubiquitin ligase. The conserved DxD motif within SseK3, which is essential for the GlcNAc transferase activity of NleB, was required for TRIM32 binding and for the capacity of SseK3 to suppress TNF-stimulated activation of NF-κB pathway. However, we did not detect GlcNAc modification of TRIM32 by SseK3, nor did the SseK3-TRIM32 interaction impact on TRIM32 ubiquitination that is associated with its activation. In addition, lack of sseK3 in Salmonella had no effect on production of the NF-κB dependent cytokine, IL-8, in HeLa cells even though TRIM32 knockdown suppressed TNF-induced NF-κB activity. Ectopically expressed SseK3 partially co-localises with TRIM32 at the trans-Golgi network, but SseK3 is not recruited to Salmonella induced vacuoles or Salmonella induced filaments during Salmonella infection. Our study has identified a novel effector-host protein interaction and suggests that SseK3 may influence NF-κB activity. However, the lack of GlcNAc modification of TRIM32 suggests that SseK3 has further, as yet unidentified, host targets.

Ubiquitylation of an internalized killer cell Ig-like receptor by Triad3A disrupts sustained NF-κB signaling.

Science.gov (United States)

Miah, S M Shahjahan; Purdy, Amanda K; Rodin, Nicholas B; MacFarlane, Alexander W; Oshinsky, Jennifer; Alvarez-Arias, Diana A; Campbell, Kerry S

2011-03-01

Killer cell Ig-like receptor (KIR) with two Ig-like domains and a long cytoplasmic domain 4 (2DL4; CD158d) is a unique KIR expressed on human NK cells, which stimulates cytokine production, but mechanisms regulating its expression and function are poorly understood. By yeast two-hybrid screening, we identified the E3 ubiquitin ligase, Triad3A, as an interaction partner for the 2DL4 cytoplasmic domain. The protein interaction was confirmed in vivo, and Triad3A expression induced polyubiquitylation and degradation of 2DL4. Overexpression of Triad3A selectively abrogated the cytokine-producing function of 2DL4, whereas Triad3A short hairpin RNA reversed ubiquitylation and restored cytokine production. Expression of Triad3A in an NK cell line did not affect receptor surface expression, internalization, or early signaling, but significantly reduced receptor turnover and suppressed sustained NF-κB activation. 2DL4 endocytosis was found to be vital to stimulate cytokine production, and Triad3A expression diminished localization of internalized receptor in early endosomes. Our results reveal a critical role for endocytosed 2DL4 receptor to generate sustained NF-κB signaling and drive cytokine production. We conclude that Triad3A is a key negative regulator of sustained 2DL4-mediated NF-κB signaling from internalized 2DL4, which functions by promoting ubiquitylation and degradation of endocytosed receptor from early endosomes.

Aqueous extract of Tribulus terrestris Linn induces cell growth arrest and apoptosis by down-regulating NF-κB signaling in liver cancer cells.

Science.gov (United States)

Kim, Hye Jin; Kim, Jin Chul; Min, Jung Sun; Kim, Mi-Jee; Kim, Ji Ae; Kor, Myung Ho; Yoo, Hwa Seung; Ahn, Jeong Keun

2011-06-14

A medicinal herb Tribulus terrestris Linn has been used to treat various diseases including hepatocellular carcinoma. The aim of the present study was to investigate the anticancer activity of Tribulus terrestris Linn (TT) in liver cancer cells. The antitumor activity of aqueous TT extract was analyzed by testing the cytotoxicity and the effect on clonogenecity in HepG2 cells. Apoptosis and cell cycle arrest induced by TT were dissected by flow cytometry and its inhibitory effect on NF-κB activity was determined by analyzing the expression levels of NF-κB/IκB subunit proteins. The suppression of NF-κB-regulated gene expression by TT was assessed by RT-PCR. TT extract repressed clonogenecity and proliferation, induced apoptosis, and enhanced accumulation in the G0/G1 phase of liver cancer cells. It also turned out that TT extract inhibited NF-κB-dependent reporter gene expression and NF-κB subunit p50 expression, while it enhanced the cellular level of IκBα by inhibiting the phosphorylation and degradation of IκBα. In addition, IKK activity was inhibited in a dose-dependent manner. Furthermore, TT extract suppressed the transcription of genes associated with cell cycle regulation, anti-apoptosis, and invasion. These data showed that TT extract blocks proliferation and induces apoptosis in human liver cancer cells through the inhibition of NF-κB signaling. Aqueous TT extract can be used as an anticancer drug for hepatocellular carcinoma patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The NF-κB p65 and p50 homodimer cooperate with IRF8 to activate iNOS transcription

International Nuclear Information System (INIS)

Simon, Priscilla S.; Sharman, Sarah K.; Lu, Chunwan; Yang, Dafeng; Paschall, Amy V.; Tulachan, Sidhartha S.; Liu, Kebin

2015-01-01

Inducible nitric oxide synthase (iNOS) metabolizes L-arginine to produce nitric oxide (NO) which was originally identified in myeloid cells as a host defense mechanism against pathogens. Recent studies, however, have revealed that iNOS is often induced in tumor cells and myeloid cells in the tumor microenvironment. Compelling experimental data have shown that iNOS promotes tumor development in certain cellular context and suppresses tumor development in other cellular conditions. The molecular mechanisms underlying these contrasting functions of iNOS is unknown. Because iNOS is often induced by inflammatory signals, it is therefore likely that these contrasting functions of iNOS could be controlled by the inflammatory signaling pathways, which remains to be determined. iNOS is expressed in colon carcinoma and myeloid cells in the tumor microenvironment. Colon carcinoma and myeloid cell lines were used to elucidate the molecular mechanisms underlying iNOS expression. Chromatin immunoprecipitation and electrophoretic mobility shift assay were used to determine the IFNγ-activated pSTAT1 and NF-κB association with the chromatin DNA of the nos2 promoter. We show here that iNOS is dramatically up-regulated in inflammed human colon tissues and in human colon carcinoma as compared to normal colon tissue. iNOS is expressed in either the colon carcinoma cells or immune cells within the tumor microenvironment. On the molecular level, the proinflammatory IFNγ and NF-κB signals induce iNOS expression in human colon cancer cells. We further demonstrate that NF-κB directly binds to the NOS2 promoter to regulate iNOS expression. Although neither the IFNγ signaling pathway nor the NF-κB signaling pathway alone is sufficient to induce iNOS expression in myeloid cells, IFNγ and NF-κB synergistically induce iNOS expression in myeloid cells. Furthermore, we determine that IFNγ up-regulates IRF8 expression to augment NF-κB induction of iNOS expression. More interestingly, we

Th17-type cytokines, IL-6 and TNF-α synergistically activate STAT3 and NF-kB to promote colorectal cancer cell growth.

Science.gov (United States)

De Simone, V; Franzè, E; Ronchetti, G; Colantoni, A; Fantini, M C; Di Fusco, D; Sica, G S; Sileri, P; MacDonald, T T; Pallone, F; Monteleone, G; Stolfi, C

2015-07-01

Colorectal cancers (CRCs) often show a dense infiltrate of cytokine-producing immune/inflammatory cells. The exact contribution of each immune cell subset and cytokine in the activation of the intracellular pathways sustaining CRC cell growth is not understood. Herein, we isolate tumor-infiltrating leukocytes (TILs) and lamina propria mononuclear cells (LPMCs) from the tumor area and the macroscopically unaffected, adjacent, colonic mucosa of patients who underwent resection for sporadic CRC and show that the culture supernatants of TILs, but not of LPMCs, potently enhance the growth of human CRC cell lines through the activation of the oncogenic transcription factors signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-kB). Characterization of immune cell complexity of TILs and LPMCs reveals no differences in the percentages of T cells, natural killer T cells, natural killer (NK) cells, macrophages and B cells. However, T cells from TILs show a functional switch compared with those from LPMCs to produce large amounts of T helper type 17 (Th17)-related cytokines (that is, interleukin-17A (IL-17A), IL-17F, IL-21 and IL-22), tumor necrosis factor-α (TNF-α) and IL-6. Individual neutralization of IL-17A, IL-17F, IL-21, IL-22, TNF-α or IL-6 does not change TIL-derived supernatant-driven STAT3 and NF-kB activation, as well as their proproliferative effect in CRC cells. In contrast, simultaneous neutralization of both IL-17A and TNF-α, which abrogates NF-kB signaling, and IL-22 and IL-6, which abrogates STAT3 signaling, reduces the mitogenic effect of supernatants in CRC cells. IL-17A, IL-21, IL-22, TNF-α and IL-6 are also produced in excess in the early colonic lesions in a mouse model of sporadic CRC, associated with enhanced STAT3/NF-kB activation. Mice therapeutically given BP-1-102, an orally bioavailable compound targeting STAT3/NF-kB activation and cross-talk, exhibit reduced colon tumorigenesis and diminished expression of

Activation of NF-κB is involved in 6-hydroxydopamine-but not MPP+-induced dopaminergic neuronal cell death: its potential role as a survival determinant

International Nuclear Information System (INIS)

Park, Seong H.; Choi, Won-Seok; Yoon, So-Young; Ahn, Young Soo; Oh, Young J.

2004-01-01

The nuclear factor-kappaB (NF-κB) family plays an important role in the control of the apoptotic response. Its activation has been demonstrated in both neurons and glial cells in many neurological disorders. In the present study, we specifically examined whether and to what extent NF-κB activation is involved in culture models of Parkinson's disease following exposure of MN9D dopaminergic neuronal cells to 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-4-phenylpyridinium ion (MPP + ). Both analysis by immunocytochemistry and of immunoblots revealed that NF-κB-p65 was translocated into the nuclei following 6-OHDA but not MPP + -treatment. A time-dependent activation of NF-κB induced by 6-OHDA but not MPP + was also demonstrated by an electrophoretic mobility shift assay. A competition assay indicated that not only NF-κB-p65 but also -p50 is involved in 6-OHDA-induced NF-κB activity. Co-treatment with an antioxidant, N-acetyl-L-cysteine, blocked 6-OHDA-induced activation of NF-κB signaling. In the presence of an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), 6-OHDA-induced cell death was accelerated while PDTC did not affect MPP + -induced cell death. Our data may point to a drug-specific activation of NF-κB as a survival determinant for dopaminergic neurons

Interleukin 6 promotes endometrial cancer growth through an autocrine feedback loop involving ERK–NF-κB signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Che, Qi; Liu, Bin-Ya; Wang, Fang-Yuan; He, Yin-Yan; Lu, Wen; Liao, Yun [Department of Obstetrics and Gynecology, Shanghai First People’s Hospital Affiliated to Shanghai Jiao Tong University, Shanghai (China); Gu, Wei, E-mail: krisgu70@163.com [Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai (China); Wan, Xiao-Ping, E-mail: wanxp@sjtu.edu.cn [Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital Affiliated to Tong Ji University, Shanghai (China)

2014-03-28

Highlights: • IL-6 could promote endometrial cancer cells proliferation. • IL-6 promotes its own production through an autocrine feedback loop. • ERK and NF-κB pathway inhibitors inhibit IL-6 production and tumor growth. • IL-6 secretion relies on the activation of ERK–NF-κB pathway axis. • An orthotopic nude endometrial carcinoma model confirms the effect of IL-6. - Abstract: Interleukin (IL)-6 as an inflammation factor, has been proved to promote cancer proliferation in several human cancers. However, its role in endometrial cancer has not been studied clearly. Previously, we demonstrated that IL-6 promoted endometrial cancer progression through local estrogen biosynthesis. In this study, we proved that IL-6 could directly stimulate endometrial cancer cells proliferation and an autocrine feedback loop increased its production even after the withdrawal of IL-6 from the medium. Next, we analyzed the mechanism underlying IL-6 production in the feedback loop and found that its production and IL-6-stimulated cell proliferation were effectively blocked by pharmacologic inhibitors of nuclear factor-kappa B (NF-κB) and extra-cellular signal-regulated kinase (ERK). Importantly, activation of ERK was upstream of the NF-κB pathways, revealing the hierarchy of this event. Finally, we used an orthotopic nude endometrial carcinoma model to confirm the effects of IL-6 on the tumor progression. Taken together, these data indicate that IL-6 promotes endometrial carcinoma growth through an expanded autocrine regulatory loop and implicate the ERK–NF-κB pathway as a critical mediator of IL-6 production, implying IL-6 to be an important therapeutic target in endometrial carcinoma.

Melatonin Inhibits Androgen Receptor Splice Variant-7 (AR-V7)-Induced Nuclear Factor-Kappa B (NF-κB) Activation and NF-κB Activator-Induced AR-V7 Expression in Prostate Cancer Cells: Potential Implications for the Use of Melatonin in Castration-Resistant Prostate Cancer (CRPC) Therapy.

Science.gov (United States)

Liu, Vincent Wing Sun; Yau, Wing Lung; Tam, Chun Wai; Yao, Kwok-Ming; Shiu, Stephen Yuen Wing

2017-05-31

A major current challenge in the treatment of advanced prostate cancer, which can be initially controlled by medical or surgical castration, is the development of effective, safe, and affordable therapies against progression of the disease to the stage of castration resistance. Here, we showed that in LNCaP and 22Rv1 prostate cancer cells transiently overexpressing androgen receptor splice variant-7 (AR-V7), nuclear factor-kappa B (NF-κB) was activated and could result in up-regulated interleukin ( IL ) -6 gene expression, indicating a positive interaction between AR-V7 expression and activated NF-κB/IL-6 signaling in castration-resistant prostate cancer (CRPC) pathogenesis. Importantly, both AR-V7-induced NF-κB activation and IL-6 gene transcription in LNCaP and 22Rv1 cells could be inhibited by melatonin. Furthermore, stimulation of AR-V7 mRNA expression in LNCaP cells by betulinic acid, a pharmacological NF-κB activator, was reduced by melatonin treatment. Our data support the presence of bi-directional positive interactions between AR-V7 expression and NF-κB activation in CRPC pathogenesis. Of note, melatonin, by inhibiting NF-κB activation via the previously-reported MT₁ receptor-mediated antiproliferative pathway, can disrupt these bi-directional positive interactions between AR-V7 and NF-κB and thereby delay the development of castration resistance in advanced prostate cancer. Apparently, this therapeutic potential of melatonin in advanced prostate cancer/CRPC management is worth translation in the clinic via combined androgen depletion and melatonin repletion.

Melatonin Inhibits Androgen Receptor Splice Variant-7 (AR-V7-Induced Nuclear Factor-Kappa B (NF-κB Activation and NF-κB Activator-Induced AR-V7 Expression in Prostate Cancer Cells: Potential Implications for the Use of Melatonin in Castration-Resistant Prostate Cancer (CRPC Therapy

Directory of Open Access Journals (Sweden)

Vincent Wing Sun Liu

2017-05-01

Full Text Available A major current challenge in the treatment of advanced prostate cancer, which can be initially controlled by medical or surgical castration, is the development of effective, safe, and affordable therapies against progression of the disease to the stage of castration resistance. Here, we showed that in LNCaP and 22Rv1 prostate cancer cells transiently overexpressing androgen receptor splice variant-7 (AR-V7, nuclear factor-kappa B (NF-κB was activated and could result in up-regulated interleukin (IL-6 gene expression, indicating a positive interaction between AR-V7 expression and activated NF-κB/IL-6 signaling in castration-resistant prostate cancer (CRPC pathogenesis. Importantly, both AR-V7-induced NF-κB activation and IL-6 gene transcription in LNCaP and 22Rv1 cells could be inhibited by melatonin. Furthermore, stimulation of AR-V7 mRNA expression in LNCaP cells by betulinic acid, a pharmacological NF-κB activator, was reduced by melatonin treatment. Our data support the presence of bi-directional positive interactions between AR-V7 expression and NF-κB activation in CRPC pathogenesis. Of note, melatonin, by inhibiting NF-κB activation via the previously-reported MT1 receptor-mediated antiproliferative pathway, can disrupt these bi-directional positive interactions between AR-V7 and NF-κB and thereby delay the development of castration resistance in advanced prostate cancer. Apparently, this therapeutic potential of melatonin in advanced prostate cancer/CRPC management is worth translation in the clinic via combined androgen depletion and melatonin repletion.

Differential NF-κB and MAPK activation underlies fluoride- and TPA-mediated CXCL8 (IL-8 induction in lung epithelial cells

Directory of Open Access Journals (Sweden)

Refsnes M

2014-12-01

Full Text Available Magne Refsnes, Tonje Skuland, Marit Låg, Per E Schwarze, Johan Øvrevik Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo, Norway Abstract: Different toxic agents have a varying potential to induce the production of the proinflammatory chemokine, CXCL8 (interleukin [IL]-8, in lung cells. A critical question is which mechanisms determine the magnitude and persistence of the CXCL8 responses to different stimuli. To approach this, we compared the potential of the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA, and sodium fluoride (NaF to induce CXCL8 responses in A549 cells, with emphasis on the importance of nuclear factor kappa B (NF-κB- and mitogen-activated protein kinase (MAPK signaling. Notably, TPA induced a greater release of CXCL8 than did NaF. Furthermore, TPA induced a strong, rapid, but transient upregulation of CXCL8 messenger (mRNA, whereas NaF induced a weaker, more delayed, but persistent upregulation. With respect to signaling, TPA led to an early, strong, and relatively transient extracellular signal-regulated kinase (ERK1/2 phosphorylation, and a less marked and even more transient phosphorylation of c-jun-N-terminal kinases (JNK1/2 and p38. In contrast, NaF elicited a lower, but relatively sustained increase in phosphorylation of ERK1/2, and a marked phosphorylation of p38 and JNK1/2, with the JNK1/2 response as most transient. Only ERK1/2 inhibition affected the TPA response, whereas inhibition of all the three MAPK cascades reduced NaF-induced CXCL8 release. TPA also induced an early, marked phosphorylation/translocation of p65 (NF-κB, whereas NaF induced slower, less pronounced effects on p65. The CXCL8 responses by TPA and NaF were reduced by p65-siRNA. In conclusion, all MAPK cascades were involved in NaF-induced CXCL8 release, whereas only ERK1/2 activation was involved in response to TPA. Furthermore, NF-κB activation appeared to be

Fisetin inhibits laryngeal carcinoma through regulation of AKT/NF-κB/mTOR and ERK1/2 signaling pathways.

Science.gov (United States)

Zhang, Xi-Jun; Jia, Shen-Shan

2016-10-01

Targeting cancer cells is crucial for improving the efficiency of laryngeal cancer treatment. However, the signaling pathway and therapeutic strategy, related to the tumor, still need further research. Dietary flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) found in many fruits and vegetables has been shown in preclinical studies to inhibit cancer growth through regulating cell cycle, apoptosis, angiogenesis, invasion and metastasis without causing any toxicity to normal cells. PI3K/AKT and ERK1/2 have been known as essential signaling pathways to modulate cell proliferation, apoptosis as well as autophagy via mTOR, Caspase-3 and NF-κB signals. In our study, flow cytometry and western blot assays suggested that apoptosis was induced by fisetin administration, promoting Caspase-3 expressions by regulating PI3K/AKT/NF-κB. Additionally, fisetin suppressed TU212 cells proliferation, which was linked with ERK1/2 inactivation. Further, the activation of PI3K/AKT-regulated mTOR was inhibited by fisetin, leading to transcription suppression and proliferation inhibition of TU212 cells. In vivo studies also showed that the tumor volume and weight of nude mice were reduced for fisetin use with KI-67 decrease and LC3II increase in tumor tissue samples. Together, our data indicated that fisetin had a potential role in controlling human laryngeal cancer through inhibiting tumor cell proliferation, inducing apoptosis and autophagy regulated by ERK1/2 and AKT/NF-κB/mTOR signaling pathways, which might provide a therapeutic strategy for laryngeal cancer inhibition in future. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Ascorbic acid suppresses endotoxemia and NF-κB signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach

Energy Technology Data Exchange (ETDEWEB)

Abhilash, P.A.; Harikrishnan, R.; Indira, M., E-mail: indiramadambath@gmail.com

2014-01-15

Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-κB activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKKβ and the protein expressions of phospho-IκBα, NF-κB, TNF-α, TGF-β{sub 1} and IL-6 were also altered in ethanol group. The expressions of fibrosis markers α-SMA, α{sub 1} (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-κB activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKKβ, which decreased the activation of NF-κB and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-κB activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKKβ and alteration of

An Oncogenic Role for Alternative NF-κB Signaling in DLBCL Revealed upon Deregulated BCL6 Expression

Directory of Open Access Journals (Sweden)

Baochun Zhang

2015-05-01

Full Text Available Diffuse large B cell lymphoma (DLBCL is a complex disease comprising diverse subtypes and genetic profiles. Possibly because of the prevalence of genetic alterations activating canonical NF-κB activity, a role for oncogenic lesions that activate the alternative NF-κB pathway in DLBCL has remained elusive. Here, we show that deletion/mutation of TRAF3, a negative regulator of the alternative NF-κB pathway, occurs in ∼15% of DLBCLs and that it often coexists with BCL6 translocation, which prevents terminal B cell differentiation. Accordingly, in a mouse model constitutive activation of the alternative NF-κB pathway cooperates with BCL6 deregulation in DLBCL development. This work demonstrates a key oncogenic role for the alternative NF-κB pathway in DLBCL development.

Glucose-6-Phosphate Dehydrogenase Enhances Antiviral Response through Downregulation of NADPH Sensor HSCARG and Upregulation of NF-κB Signaling

Directory of Open Access Journals (Sweden)

Yi-Hsuan Wu

2015-12-01

Full Text Available Glucose-6-phosphate dehydrogenase (G6PD-deficient cells are highly susceptible to viral infection. This study examined the mechanism underlying this phenomenon by measuring the expression of antiviral genes—tumor necrosis factor alpha (TNF-α and GTPase myxovirus resistance 1 (MX1—in G6PD-knockdown cells upon human coronavirus 229E (HCoV-229E and enterovirus 71 (EV71 infection. Molecular analysis revealed that the promoter activities of TNF-α and MX1 were downregulated in G6PD-knockdown cells, and that the IκB degradation and DNA binding activity of NF-κB were decreased. The HSCARG protein, a nicotinamide adenine dinucleotide phosphate (NADPH sensor and negative regulator of NF-κB, was upregulated in G6PD-knockdown cells with decreased NADPH/NADP+ ratio. Treatment of G6PD-knockdown cells with siRNA against HSCARG enhanced the DNA binding activity of NF-κB and the expression of TNF-α and MX1, but suppressed the expression of viral genes; however, the overexpression of HSCARG inhibited the antiviral response. Exogenous G6PD or IDH1 expression inhibited the expression of HSCARG, resulting in increased expression of TNF-α and MX1 and reduced viral gene expression upon virus infection. Our findings suggest that the increased susceptibility of the G6PD-knockdown cells to viral infection was due to impaired NF-κB signaling and antiviral response mediated by HSCARG.

Gallic acid inhibits gastric cancer cells metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity

Energy Technology Data Exchange (ETDEWEB)

Ho, Hsieh-Hsun [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Chang, Chi-Sen [Department of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Division of Gastroenterology, Taichung Veterans General Hospital, Taichung 402, Taiwan (China); Ho, Wei-Chi [Division of Gastroenterology, Jen-Ai Hospital, Taichung 402, Taiwan (China); Liao, Sheng-You [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Lin, Wea-Lung [Department of Pathology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pathology, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Wang, Chau-Jong, E-mail: wcj@csmu.edu.tw [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China)

2013-01-01

Our previous study demonstrated the therapeutic potential of gallic acid (GA) for controlling tumor metastasis through its inhibitory effect on the motility of AGS cells. A noteworthy finding in our previous experiment was increased RhoB expression in GA-treated cells. The aim of this study was to evaluate the role of RhoB expression on the inhibitory effects of GA on AGS cells. By applying the transfection of RhoB siRNA into AGS cells and an animal model, we tested the effect of GA on inhibition of tumor growth and RhoB expression. The results confirmed that RhoB-siRNA transfection induced GA to inhibit AGS cells’ invasive growth involving blocking the AKT/small GTPase signals pathway and inhibition of NF-κB activity. Finally, we evaluated the effect of GA on AGS cell metastasis by colonization of tumor cells in nude mice. It showed GA inhibited tumor cells growth via the expression of RhoB. These data support the inhibitory effect of GA which was shown to inhibit gastric cancer cell metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity. Thus, GA might be a potential agent in treating gastric cancer. Highlights: ► GA could downregulate AKT signal via increased expression of RhoB. ► GA inhibits metastasis in vitro in gastric carcinoma. ► GA inhibits tumor growth in nude mice model.

Rivaroxaban attenuates thrombosis by targeting the NF-κB signaling pathway in a rat model of deep venous thrombus.

Science.gov (United States)

Ma, Junhao; Li, Xinxi; Wang, Yang; Yang, Zhenwei; Luo, Jun

2017-12-01

Anticoagulant therapy is commonly used for the prevention and treatment of patients with deep venous thrombus. Evidence has shown that rivaroxaban is a potential oral anticoagulant drug for the acute treatment of venous thromboembolism. However, the rivaroxaban-mediated molecular mechanism involved in the progression of deep venous thrombosis has not been investigated. In the present study, we investigated the efficacy of rivaroxaban and the underlying signaling pathways in the prevention and treatment of rats with deep venous thrombosis. A rat model with deep vein thrombus formation was established and received treatment with rivaroxaban or PBS as control. The thrombin-activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor-1 (PAI-1) were analyzed both in vitro and in vivo. The progression of thrombosis and stroke was evaluated after treatment with rivaroxaban or PBS. Nuclear factor-κB (NF-κB) signaling pathway in venous endothelial cells and in the rat model of deep venous thrombus was assessed. The therapeutic effects of rivaroxaban were evaluated as determined by changes in deep venous thrombosis in the rat model. Our results showed that rivaroxaban markedly inhibited TAFI and PAI-1 expression levels, neutrophils, tissue factor, neutrophil extracellular traps (NETs), myeloperoxidase and macrophages in venous endothelial cells and in the rat model of deep venous thrombus. Expression levels of ADP, PAIs, von Willebrand factor (vWF) and thromboxane were downregulated in vein endothelial cells and in serum from the experimental rats. Importantly, the incidences of inferior vena cava filter thrombus were protected by rivaroxaban during heparin-induced thrombolysis deep venous thrombosis in the rat model. We observed that activity of the NF-κB signaling pathway was inhibited by rivaroxaban in vein endothelial cells both in vitro and in vivo. Notably, immunohistology indicated that rivaroxaban attenuated deep venous thrombosis and the

Anthocyanin prevents CD40-activated proinflammatory signaling in endothelial cells by regulating cholesterol distribution.

Science.gov (United States)

Xia, Min; Ling, Wenhua; Zhu, Huilian; Wang, Qing; Ma, Jing; Hou, Mengjun; Tang, Zhihong; Li, Lan; Ye, Qinyuan

2007-03-01

Intracellular tumor necrosis factor receptor-associated factors (TRAFs) translocation to lipid rafts is a key element in CD40-induced signaling. The purpose of this study was to investigate the influence of anthocyanin on CD40-mediated proinflammatory events in human endothelial cells and the underlying possible molecular mechanism. Treatment of endothelial cells with anthocyanin prevented from CD40-induced proinflammatory status, measured by production of IL-6, IL-8, and monocyte chemoattractant protein-1 through inhibiting CD40-induced nuclear factor-kappaB (NF-kappaB) activation. TRAF-2 played pivotal role in CD40-NF-kappaB pathway as TRAF-2 small interference RNA (siRNA) diminished CD40-induced NF-kappaB activation and inflammation. TRAF-2 overexpression increased CD40-mediated NF-kappaB activation. Moreover, TRAF-2 almost totally recruited to lipid rafts after stimulation by CD40 ligand and depletion of cholesterol diminished CD40-mediated NF-kappaB activation. Exposure to anthocyanin not only interrupted TRAF-2 recruitment to lipid rafts but also decreased cholesterol content in Triton X-100 insoluble lipid rafts. However, anthocyanin did not influence the interaction between CD40 ligand and CD40 receptor. Our findings suggest that anthocyanin protects from CD40-induced proinflammatory signaling by preventing TRAF-2 translocation to lipid rafts through regulation of cholesterol distribution, which thereby may represent a mechanism that would explain the anti-inflammatory response of anthocyanin.

Blocking NF-κB: an inflammatory issue.

Science.gov (United States)

Rahman, Arshad; Fazal, Fabeha

2011-11-01

The nuclear factor (NF)-κB is considered the master regulator of inflammatory responses. Studies in mouse models have established this transcription factor as an important mediator of many inflammatory disease states, including pulmonary diseases such as acute lung injury and acute respiratory distress syndrome. Endothelial cells provide the first barrier for leukocytes migrating to the inflamed sites and hence offer an attractive cellular context for targeting NF-κB for treatment of these diseases. However, recent studies showing that NF-κB also plays an important role in resolution phase of inflammation and in tissue repair and homeostasis have challenged the view of therapeutic inhibition of NF-κB. This article reviews the regulation of NF-κB in the context of endothelial cell signaling and provides a perspective on why "dampening" rather than "abolishing" NF-κB activation may be a safe and effective treatment strategy for inflammation-associated pulmonary and other inflammatory diseases.

Ethanol enhances arsenic-induced cyclooxygenase-2 expression via both NFAT and NF-κB signalings in colorectal cancer cells

Energy Technology Data Exchange (ETDEWEB)

Wang, Lei; Hitron, John Andrew [Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Wise, James T.F. [Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Son, Young-Ok; Roy, Ram Vinod [Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Kim, Donghern; Dai, Jin [Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Pratheeshkumar, Poyil [Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Zhang, Zhuo [Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Xu, Mei; Luo, Jia [Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@uky.edu [Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

2015-10-15

Arsenic is a known carcinogen to humans, and chronic exposure to environmental arsenic is a worldwide health concern. As a dietary factor, ethanol carries a well-established risk for malignancies, but the effects of co-exposure to arsenic and ethanol on tumor development are not well understood. In the present study, we hypothesized that ethanol would enhance the function of an environmental carcinogen such as arsenic through increase in COX-2 expression. Our in vitro results show that ethanol enhanced arsenic-induced COX-2 expression. We also show that the increased COX-2 expression associates with intracellular ROS generation, up-regulated AKT signaling, with activation of both NFAT and NF-κB pathways. We demonstrate that antioxidant enzymes have an inhibitory effect on arsenic/ethanol-induced COX-2 expression, indicating that the responsive signaling pathways from co-exposure to arsenic and ethanol relate to ROS generation. In vivo results also show that co-exposure to arsenic and ethanol increased COX-2 expression in mice. We conclude that ethanol enhances arsenic-induced COX-2 expression in colorectal cancer cells via both the NFAT and NF-κB pathways. These results imply that, as a common dietary factor, ethanol ingestion may be a compounding risk factor for arsenic-induced carcinogenesis/cancer development. - Highlights: • Arsenic is able to induce Cox-2 expression in colorectal cancer cells. • Ethanol, a diet nutritional factor, could enhance arsenic-induced Cox-2. • The up-regulation of Cox-2 via both NFAT and NF-κB activities.

Ethanol enhances arsenic-induced cyclooxygenase-2 expression via both NFAT and NF-κB signalings in colorectal cancer cells

International Nuclear Information System (INIS)

Wang, Lei; Hitron, John Andrew; Wise, James T.F.; Son, Young-Ok; Roy, Ram Vinod; Kim, Donghern; Dai, Jin; Pratheeshkumar, Poyil; Zhang, Zhuo; Xu, Mei; Luo, Jia; Shi, Xianglin

2015-01-01

Arsenic is a known carcinogen to humans, and chronic exposure to environmental arsenic is a worldwide health concern. As a dietary factor, ethanol carries a well-established risk for malignancies, but the effects of co-exposure to arsenic and ethanol on tumor development are not well understood. In the present study, we hypothesized that ethanol would enhance the function of an environmental carcinogen such as arsenic through increase in COX-2 expression. Our in vitro results show that ethanol enhanced arsenic-induced COX-2 expression. We also show that the increased COX-2 expression associates with intracellular ROS generation, up-regulated AKT signaling, with activation of both NFAT and NF-κB pathways. We demonstrate that antioxidant enzymes have an inhibitory effect on arsenic/ethanol-induced COX-2 expression, indicating that the responsive signaling pathways from co-exposure to arsenic and ethanol relate to ROS generation. In vivo results also show that co-exposure to arsenic and ethanol increased COX-2 expression in mice. We conclude that ethanol enhances arsenic-induced COX-2 expression in colorectal cancer cells via both the NFAT and NF-κB pathways. These results imply that, as a common dietary factor, ethanol ingestion may be a compounding risk factor for arsenic-induced carcinogenesis/cancer development. - Highlights: • Arsenic is able to induce Cox-2 expression in colorectal cancer cells. • Ethanol, a diet nutritional factor, could enhance arsenic-induced Cox-2. • The up-regulation of Cox-2 via both NFAT and NF-κB activities.

Assessment of Nanobiotechnology-Targeted siRNA Designed to Inhibit NF-KappaB Classical and Alternative Signaling in Breast Tumor Macrophages

Science.gov (United States)

2014-07-01

Intraductal Injection of LPS as a Mouse Model of Mastitis : Signaling Visualized via an NF-κB Reporter Transgenic. J Vis Exp. (67). pii: 4030. 2012. PMID...injection of LPS as a mouse model of mastitis : signaling visualized via an NF-κB reporter transgenic. Journal of Visualized Experiments 2012. 4(67...supplies, including media, fetal bovine serum, antibiotics, and nonessential amino acids, were obtained from Life Technologies (Carlsbad, CA). The

Identification of a novel TIF-IA-NF-κB nucleolar stress response pathway.

Science.gov (United States)

Chen, Jingyu; Lobb, Ian T; Morin, Pierre; Novo, Sonia M; Simpson, James; Kennerknecht, Kathrin; von Kriegsheim, Alex; Batchelor, Emily E; Oakley, Fiona; Stark, Lesley A

2018-06-05

p53 as an effector of nucleolar stress is well defined, but p53 independent mechanisms are largely unknown. Like p53, the NF-κB transcription factor plays a critical role in maintaining cellular homeostasis under stress. Many stresses that stimulate NF-κB also disrupt nucleoli. However, the link between nucleolar function and activation of the NF-κB pathway is as yet unknown. Here we demonstrate that artificial disruption of the PolI complex stimulates NF-κB signalling. Unlike p53 nucleolar stress response, this effect does not appear to be linked to inhibition of rDNA transcription. We show that specific stress stimuli of NF-κB induce degradation of a critical component of the PolI complex, TIF-IA. This degradation precedes activation of NF-κB and is associated with increased nucleolar size. It is mimicked by CDK4 inhibition and is dependent upon a novel pathway involving UBF/p14ARF and S44 of the protein. We show that blocking TIF-IA degradation blocks stress effects on nucleolar size and NF-κB signalling. Finally, using ex vivo culture, we show a strong correlation between degradation of TIF-IA and activation of NF-κB in freshly resected, human colorectal tumours exposed to the chemopreventative agent, aspirin. Together, our study provides compelling evidence for a new, TIF-IA-NF-κB nucleolar stress response pathway that has in vivo relevance and therapeutic implications.

Melatonin enhances the anti-tumor effect of fisetin by inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways.

Directory of Open Access Journals (Sweden)

Canhui Yi

Full Text Available Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy.

Melatonin Enhances the Anti-Tumor Effect of Fisetin by Inhibiting COX-2/iNOS and NF-κB/p300 Signaling Pathways

Science.gov (United States)

Yu, Zhenlong; Xiao, Yao; Wang, Jingshu; Qiu, Huijuan; Yu, Wendan; Tang, Ranran; Yuan, Yuhui; Guo, Wei; Deng, Wuguo

2014-01-01

Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy. PMID:25000190

A Staphylococcus aureus TIR domain protein virulence factor blocks TLR2-mediated NF-κB signaling.

Science.gov (United States)

Askarian, Fatemeh; van Sorge, Nina M; Sangvik, Maria; Beasley, Federico C; Henriksen, Jørn R; Sollid, Johanna U E; van Strijp, Jos A G; Nizet, Victor; Johannessen, Mona

2014-01-01

Signaling through Toll-like receptors (TLRs), crucial molecules in the induction of host defense responses, requires adaptor proteins that contain a Toll/interleukin-1 receptor (TIR) domain. The pathogen Staphylococcus aureus produces several innate immune-evasion molecules that interfere with the host's innate immune response. A database search analysis suggested the presence of a gene encoding a homologue of the human TIR domain in S. aureus MSSA476 which was named staphylococcal TIR domain protein (TirS). Ectopic expression of TirS in human embryonic kidney, macrophage and keratinocyte cell lines interfered with signaling through TLR2, including MyD88 and TIRAP, NF-κB and/or mitogen-activated protein kinase pathways. Moreover, the presence of TirS reduced the levels of cytokines MCP-1 and G-CSF secreted in response to S. aureus. The effects on NF-κB pathway were confirmed using S. aureus MSSA476 wild type, an isogenic mutant MSSA476ΔtirS, and complemented MSSA476ΔtirS +pTirS in a Transwell system where bacteria and host cells were physically separated. Finally, in a systematic mouse infection model, TirS promoted bacterial accumulation in several organs 4 days postinfection. The results of this study reveal a new S. aureus virulence factor that can interfere with PAMP-induced innate immune signaling in vitro and bacterial survival in vivo. © 2014 S. Karger AG, Basel.

Experimental study on 1,25(OH)2 D3 amelioration of oral lichen planus through regulating NF-κB signaling pathway.

Science.gov (United States)

Du, J; Li, R; Yu, F; Yang, F; Wang, J; Chen, Q; Wang, X; Zhao, B; Zhang, F

2017-09-01

To explore the protective function of vitamin D (VD)/vitamin D receptor (VDR) on the development of oral lichen planus (OLP) and elaborate the underling mechanism of it. H&E staining, myeloid peroxidase (MPO) assays, quantitative PCR (qPCR), Western blotting, and Elisa were used to test the human biopsies and serum. QPCR, Western blotting, Elisa, and siRNA transfection were also performed in LPS-induced keratinocytes to observe the functions of vitamin D and VDR. The lack of VDR in the diseased biopsies from OLP patients was associated with activated helper T-cell type 1 (Th1)-driven inflammatory response. Importantly, the status of serum 25-hydroxyvitamin D of OLP patients was reduced consistently. In a cultured cell model, 1,25(OH) 2 D 3 could downregulate excessive production of pro-inflammatory factors induced by lipopolysaccharide (LPS) in keratinocyte HaCat cells. Mechanistically, even though LPS-induced cytokines in keratinocytes were inhibited both by nuclear factor-κB (NF-κB) inhibitor and by activator protein 1 (AP-1) inhibitor, VDR-dependent 1,25(OH) 2 D 3 blocked the activation of phosphorylated-NF-κB p65 rather than c-Jun/c-Fos in the presence of LPS stimulation. These results suggest that 1,25(OH) 2 D 3 plays an anti-inflammatory role in OLP by mediating NF-κB signaling pathway but not AP-1 signaling pathway with a VDR-dependent manner, predicting vitamin D supplement may be a potential strategy for the OLP management. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do, E-mail: ydjung@chonnam.ac.kr

2012-03-01

Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells

Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

International Nuclear Information System (INIS)

Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do

2012-01-01

Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H 2 O 2 ) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H 2 O 2 increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells treated with nicotine

Flavonoids Identified from Korean Scutellaria baicalensis Georgi Inhibit Inflammatory Signaling by Suppressing Activation of NF-κB and MAPK in RAW 264.7 Cells

Directory of Open Access Journals (Sweden)

Gyeong-Eun Hong

2013-01-01

Full Text Available Scutellaria baicalensis Georgi has been used as traditional medicine for treating inflammatory diseases, hepatitis, tumors, and diarrhea in Asia. Hence, we investigated the anti-inflammatory effect and determined the molecular mechanism of action of flavonoids isolated from Korean S. baicalensis G. in lipopolysaccharide- (LPS- stimulated RAW 264.7 macrophages. A 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay was performed to examine cytotoxicity of the flavonoids at various concentrations of 10, 40, 70, and 100 µg/mL. No cytotoxicity was observed in RAW 264.7 cells at these concentrations. Furthermore, the flavonoids decreased production of inflammatory mediators such as inducible nitric oxide synthase, cyclooxygenase-2, interleukin-6, and tumor necrosis factor-alpha and inhibited phosphorylation of nuclear factor-kappa B (NF-κB and mitogen-activated protein kinases (MAPKs in LPS-induced RAW 264.7 cells. Moreover, to identify the differentially expressed proteins in RAW 264.7 cells of the control, LPS-treated, and flavonoid-treated groups, two-dimensional gel electrophoresis and mass spectrometry were conducted. The identified proteins were involved in the inflammatory response and included PRKA anchor protein and heat shock protein 70 kD. These findings suggest that the flavonoids isolated from S. baicalensis G. might have anti-inflammatory effects that regulate the expression of inflammatory mediators by inhibiting the NF-κB signaling pathway via the MAPK signaling pathway in RAW 264.7 cells.

The potent suppressive effect of β-d-mannuronic acid (M2000) on molecular expression of the TLR/NF-kB Signaling Pathway in ankylosing spondylitis patients.

Science.gov (United States)

Roozbehkia, Maryam; Mahmoudi, Mahdi; Aletaha, Somaye; Rezaei, Nima; Fattahi, Mohammad Javad; Jafarnezhad-Ansariha, Fahimeh; Barati, Anis; Mirshafiey, Abbas

2017-11-01

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by the inflammation of sacroiliac joints and axial skeleton. A combination of genetic, environmental and immunological factors are involved in AS's pathogenesis. TLRs are type I transmembrane glycoproteins that play a crucial role in the innate immune responses against invading pathogens. Observational studies have demonstrated a possible association between TLR dysregulation and AS. The β-d-mannuronic acid (M2000), as a novel NSAID with immunosuppressive property, has shown an inhibitory effect on Toll-like receptor (TLR) 2, 4 signaling in HEK293 cells. In the present study, we investigated the gene expression of Myd88, IKB-alpha, NF-kB and MAPK14 (genes of the TLR/NF-kB Signaling Pathway) in AS patients in comparison to healthy subjects and also the effect of β-d-mannuronic acid on disease activity and mRNA expression of these molecules in affected patients. We showed for the first time that the gene expression level of Myd88, IKB-alpha, NF-kB and MAPK14 was higher in AS patients in comparison to healthy subjects. Moreover we confirmed that the β-d-mannuronic acid not just reduced significantly the disease activity of AS individuals compared to placebo, but also it could significantly decrease the expression level of genes associated with TLR/NF-kB Signaling Pathway in treated patients with M2000. These results may provide a new therapeutic approach to attenuate inflammatory responses in AS patients, (Identified; IRCT 2013062213739N1). Copyright © 2017. Published by Elsevier B.V.

Tanreqing Injection Attenuates Lipopolysaccharide-Induced Airway Inflammation through MAPK/NF-κB Signaling Pathways in Rats Model

Science.gov (United States)

Liu, Wei; Jiang, Hong-li; Cai, Lin-li; Yan, Min; Dong, Shou-jin; Mao, Bing

2016-01-01

Background. Tanreqing injection (TRQ) is a commonly used herbal patent medicine for treating inflammatory airway diseases in view of its outstanding anti-inflammatory properties. In this study, we explored the signaling pathways involved in contributions of TRQ to LPS-induced airway inflammation in rats. Methods/Design. Adult male Sprague Dawley (SD) rats randomly divided into different groups received intratracheal instillation of LPS and/or intraperitoneal injection of TRQ. Bronchoalveolar Lavage Fluid (BALF) and lung samples were collected at 24 h, 48 h, and 96 h after TRQ administration. Protein and mRNA levels of tumor necrosis factor- (TNF-) α, Interleukin- (IL-) 1β, IL-6, and IL-8 in BALF and lung homogenate were observed by ELISA and real-time PCR, respectively. Lung sections were stained for p38 MAPK and NF-κB detection by immunohistochemistry. Phospho-p38 MAPK, phosphor-extracellular signal-regulated kinases ERK1/2, phospho-SAPK/JNK, phospho-NF-κB p65, phospho-IKKα/β, and phospho-IκB-α were measured by western blot analysis. Results. The results showed that TRQ significantly counteracted LPS-stimulated release of TNF-α, IL-1β, IL-6, and IL-8, attenuated cells influx in BALF, mitigated mucus hypersecretion, suppressed phosphorylation of NF-κB p65, IκB-α, ΙKKα/β, ERK1/2, JNK, and p38 MAPK, and inhibited p38 MAPK and NF-κB p65 expression in rat lungs. Conclusions. Results of the current research indicate that TRQ possesses potent exhibitory effects in LPS-induced airway inflammation by, at least partially, suppressing the MAPKs and NF-κB signaling pathways, in a general dose-dependent manner. PMID:27366191

Reactive oxygen species-dependent Toll/NF-κB activation in the Drosophila hematopoietic niche confers resistance to wasp parasitism.

Science.gov (United States)

Louradour, Isabelle; Sharma, Anurag; Morin-Poulard, Ismael; Letourneau, Manon; Vincent, Alain; Crozatier, Michèle; Vanzo, Nathalie

2017-11-01

Hematopoietic stem/progenitor cells in the adult mammalian bone marrow ensure blood cell renewal. Their cellular microenvironment, called 'niche', regulates hematopoiesis both under homeostatic and immune stress conditions. In the Drosophila hematopoietic organ, the lymph gland, the posterior signaling center (PSC) acts as a niche to regulate the hematopoietic response to immune stress such as wasp parasitism. This response relies on the differentiation of lamellocytes, a cryptic cell type, dedicated to pathogen encapsulation and killing. Here, we establish that Toll/NF-κB pathway activation in the PSC in response to wasp parasitism non-cell autonomously induces the lymph gland immune response. Our data further establish a regulatory network where co-activation of Toll/NF-κB and EGFR signaling by ROS levels in the PSC/niche controls lymph gland hematopoiesis under parasitism. Whether a similar regulatory network operates in mammals to control emergency hematopoiesis is an open question.

Dexmedetomidine reduces ventilator-induced lung injury (VILI by inhibiting Toll-like receptor 4 (TLR4/nuclear factor (NF-κB signaling pathway

Directory of Open Access Journals (Sweden)

Hongli Chen

2018-02-01

Full Text Available Mechanical ventilation (MV may lead to ventilator-induced lung injury (VILI. Previous research has shown that dexmedetomidine attenuates pulmonary inflammation caused by MV, but the underlying mechanisms remain unclear. Our study aims to test whether dexmedetomidine has a protective effect against VILI and to explore the possible molecular mechanisms using the rat model. Thirty adult male Wistar rats weighing 200-250 g were randomly assigned to 5 groups (n = 6: control, low tidal volume MV (LMV, high tidal volume (HVT MV (HMV, HVT MV + dexmedetomidine (DEX, HVT MV + dexmedetomidine + yohimbine (DEX+Y. Rats were euthanized after being ventilated for 4 hours. Pathological changes, lung wet/dry (W/D weight ratio, lung myeloperoxidase (MPO activity, levels of inflammatory cytokines (i.e., interleukin [IL]-1β, tumor necrosis factor alpha [TNF-α], and IL-6 in the bronchoalveolar lavage fluid (BALF and lung tissues, expression of Toll-like receptor 4 (TLR4 and nuclear factor (NF-κB, and activation of NF-κB in lung tissues were measured. Compared with HMV, DEX group showed fewer pathological changes, lower W/D ratios and decreased MPO activity of the lung tissues and lower concentrations of the inflammatory cytokines in the BALF and lung tissues. Dexmedetomidine significantly inhibited the expression of TLR4 and NF-κB and activation of NF-κB. Yohimbine partly alleviated the effects of dexmedetomidine. Dexmedetomidine reduced the inflammatory response to HVT-MV and had a protective effect against VILI, with the inhibition of the TLR4/NF-κB signaling pathway, at least partly via α2-adrenoceptors.

Silencing of FKBP51 alleviates the mechanical pain threshold, inhibits DRG inflammatory factors and pain mediators through the NF-kappaB signaling pathway.

Science.gov (United States)

Yu, Hong-Mei; Wang, Qi; Sun, Wen-Bo

2017-09-05

Neuropathic pain is chronic pain caused by lesions or diseases of the somatosensory system, currently available analgesics provide only temporal relief. The precise role of FK506 binding protein 51 (FKBP51) in neuropathic pain induced by chronic constriction injury (CCI) is not clear. The purpose of the present study was to investigate the effects and possible mechanisms of FKBP51 in neuropathic pain in the rat model of CCI. Our results showed that FKBP51 was obviously upregulated in a time-dependent manner in the dorsal root ganglion (DRG) of CCI rats. Additionally, silencing of FKBP51 remarkably attenuated mechanical allodynia and thermal hyperalgesia as reflected by paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) in CCI rats. Moreover, knockdown of FKBP51 reduced the production of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) expression in the DRG of CCI rats. Furthermore, we revealed that inhibition of FKBP51 greatly suppressed the activation of the NF-kappaB (NF-κB) signaling in the DRG of CCI rats. Interestingly, similar to the FKBP51 siRNA (si-FKBP51), ammonium pyrrolidinedithiocarbamate (PDTC, an inhibitor of NF-κB) also alleviated neuropathic pain and neuro-inflammation, indicating that knockdown of FKBP51 alleviated neuropathic pain development of CCI rats by inhibiting the activation of NF-κB signaling pathway. Taken together, our findings indicate that FKBP51 may serve as a novel therapeutic target for neuropathic pain. Copyright © 2017. Published by Elsevier B.V.

Attenuation of liver pro-inflammatory responses by Zingiber officinale via inhibition of NF-kappa B activation in high-fat diet-fed rats.

Science.gov (United States)

Li, Xiao-Hong; McGrath, Kristine C-Y; Nammi, Srinivas; Heather, Alison K; Roufogalis, Basil D

2012-03-01

The aim of this study was to investigate whether treatment with a ginger (Zingiber officinale) extract of high-fat diet (HFD)-fed rats suppresses Nuclear factor-kappa B (NF-κB)-driven hepatic inflammation and to subsequently explore the molecular mechanisms in vitro. Adult male Sprague-Dawley rats were treated with an ethanolic extract of Zingiber officinale (400 mg/kg) along with a HFD for 6 weeks. Hepatic cytokine mRNA levels, cytokine protein levels and NF-κB activation were measured by real-time PCR, Western blot and an NF-κB nuclear translocation assay, respectively. In vitro, cell culture studies were carried out in human hepatocyte (HuH-7) cells by treatment with Zingiber officinale (100 μg/mL) for 24 hr prior to interleukin-1β (IL-1β, 8 ng/mL)-induced inflammation. We showed that Zingiber officinale treatment decreased cytokine gene TNFα and IL-6 expression in HFD-fed rats, which was associated with suppression of NF-κB activation. In vitro, Zingiber officinale treatment decreased NF-κB-target inflammatory gene expression of IL-6, IL-8 and serum amyloid A1 (SAA1), while it suppressed NF-κB activity, IκBα degradation and IκB kinase (IKK) activity. In conclusion, Zingiber officinale suppressed markers of hepatic inflammation in HFD-fed rats, as demonstrated by decreased hepatic cytokine gene expression and decreased NF-κB activation. The study demonstrates that the anti-inflammatory effect of Zingiber officinale occurs at least in part through the NF-κB signalling pathway. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

Vaccinium bracteatum Thunb. Exerts Anti-Inflammatory Activity by Inhibiting NF-κB Activation in BV-2 Microglial Cells.

Science.gov (United States)

Kwon, Seung-Hwan; Ma, Shi-Xun; Ko, Yong-Hyun; Seo, Jee-Yeon; Lee, Bo-Ram; Lee, Taek Hwan; Kim, Sun Yeou; Lee, Seok-Yong; Jang, Choon-Gon

2016-09-01

This study was designed to evaluate the pharmacological effects of Vaccinium bracteatum Thunb. methanol extract (VBME) on microglial activation and to identify the underlying mechanisms of action of these effects. The anti-inflammatory properties of VBME were studied using lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. We measured the production of nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase (COX)-2, prostaglandin E₂ (PGE₂), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) as inflammatory parameters. We also examined the effect of VBME on intracellular reactive oxygen species (ROS) production and the activity of nuclear factor-kappa B p65 (NF-κB p65). VBME significantly inhibited LPS-induced production of NO and PGE2 and LPS-mediated upregulation of iNOS and COX-2 expression in a dose-dependent manner; importantly, VBME was not cytotoxic. VBME also significantly reduced the generation of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6. In addition, VBME significantly dampened intracellular ROS production and suppressed NF-κB p65 translocation by blocking IκB-α phosphorylation and degradation in LPS-stimulated BV2 cells. Our findings indicate that VBME inhibits the production of inflammatory mediators in BV-2 microglial cells by suppressing NF-κB signaling. Thus, VBME may be useful in the treatment of neurodegenerative diseases due to its ability to inhibit inflammatory mediator production in activated BV-2 microglial cells.

Induction of cyclooxygenase-2 in macrophages by catalase: role of NF-kappaB and PI3K signaling pathways.

Science.gov (United States)

Jang, Byeong-Churl; Kim, Do-Hyun; Park, Jong-Wook; Kwon, Taeg Kyu; Kim, Sang-Pyo; Song, Dae-Kyu; Park, Jong-Gu; Bae, Jae-Hoon; Mun, Kyo-Chul; Baek, Won-Ki; Suh, Min-Ho; Hla, Timothy; Suh, Seong-Il

2004-04-02

Induction of COX-2 by catalase in smooth muscle cells, endothelial cells, and neuronal cells has been previously reported. However, the mechanism by which catalase up-regulates COX-2 remains poorly understood. In this study, we investigated the effect of catalase on induction of COX-2 in macrophages. The addition of catalase into Raw 264.7 macrophages induced COX-2 expression that was correlated with increased COX-2 transcription and mRNA stability. Catalase also induced activation of NF-kappaB, PI3K, ERKs, p38s, or JNKs. Catalase-induced COX-2 expression was abrogated by treatment of MG-132 (a NF-kappaB inhibitor) or LY294002 (a PI3K inhibitor), but not by treatment of PD98059 (an ERK inhibitor), SB203580 (a p38 inhibitor), or SP600125 (a JNK inhibitor). Moreover, inhibition of PI3K by LY294002 caused partial decrease of catalase-induced COX-2 transcription and steady-state COX-2 transcript levels, but not COX-2 mRNA stability. Together, these results suggest that catalase induces the expression of COX-2 in Raw 264.7 macrophages, and the induction is related with activation of NF-kappaB transcription factor and PI3K signaling pathway.

Rhein inhibits malignant phenotypes of human renal cell carcinoma by impacting on MAPK/NF-κB signaling pathways

Directory of Open Access Journals (Sweden)

Ma YL

2018-03-01

Full Text Available Ya-Li Ma,* Fang Chen,* Jun ShiDepartment of Nephrology, Huaihe Hospital Henan University, Kaifeng, People’s Republic of China*These authors contributed equally to this workBackground: Rhein, an anthraquinone derivative of rhubarb, is traditionally used in Chinese herbal medicine. Now emerging studies suggest its antitumor properties in many human cancers. The present study aims to investigate the antitumor role of Rhein and its possible mechanism in human renal cell carcinoma (RCC.Materials and methods: Three RCC cell lines (A489, 786-O and ACHN were used as the cell models. We applied CCK-8, cell counting, colony formation, wound healing and Transwell assays to assess the antitumor roles of Rhein in RCC cells in vitro. The therapeutic efficacy of Rhein was further evaluated by intraperitoneal administrations in tumor formation of mice. Western blot was used to investigate the underlying mechanisms of action of Rhein.Results: Rhein inhibited RCC cell proliferation in a dose- and time-dependent manner. It also suppressed RCC cell migration and invasion in vitro. Moreover, Rhein was able to inhibit tumor growth in nude mice by intraperitoneal administration in vivo. Mechanistically, the protein levels of phosphorylated MAPK (mitogen-activated protein kinase, extracellular signal-regulated kinase and c-Jun N-terminal kinase, phosphorylated Akt and two targets of NF-κB (nuclear factor kappa-light-chain enhancer of activated B cells pathway, matrix metalloproteinase 9 and CCND1 were all markedly reduced by Rhein treatment.Conclusion: Rhein processed the antitumor effects in RCC cells by inhibiting cell proliferation, migration and invasion, and these tumor-suppressing functions might be mediated by MAPK/NF-κB signaling pathways.Keywords: Rhein, renal cell carcinoma, antitumor effects, MAPK, NF-κB

NF1 Signal Transduction and Vascular Dysfunction

Science.gov (United States)

2015-05-01

microenvironment that promotes much of the pathology associated with the disease . Moreover we hypothesize that a mechanistic consequence of the loss...obliteration of the normal red pulp architecture. In addition, we found significant peri-aveolar and peri-vascular inflammatory infiltrates in the lung...the mouse model of NF1 disease in the endothelium we proposed and have done experiments investigating the loss of endothelial NF1 in the adult

Tenascin-C induces resistance to apoptosis in pancreatic cancer cell through activation of ERK/NF-κB pathway.

Science.gov (United States)

Shi, Meiyan; He, Xiaodan; Wei, Wei; Wang, Juan; Zhang, Ti; Shen, Xiaohong

2015-06-01

As a glycol-protein located in extracellular matrix (ECM), tenascin-C (TNC) is absent in most normal adult tissues but is highly expressed in the majority of malignant solid tumors. Pancreatic cancer is characterized by an abundant fibrous tissue rich in TNC. Although it was reported that TNC's expression increased in the progression from low-grade precursor lesions to invasive cancer and was associated with tumor differentiation in human pancreatic cancer, studies on the relations between TNC and tumor progression in pancreatic cancer were rare. In this study, we performed an analysis to determine the effects of TNC on modulating cell apoptosis and chemo-resistance and explored its mechanisms involving activation in pancreatic cancer cell. The expressions of TNC, ERK1/2/p-ERK1/2, Bcl-xL and Bcl-2 were detected by immunohistochemistry and western blotting. Then the effects of exogenous and endogenous TNC on the regulation of tumor proliferation, apoptosis and gemcitabine cytotoxicity were investigated. The associations among the TNC knockdown, TNC stimulation and expressions of ERK1/2/NF-κB/p65 and apoptotic regulatory proteins were also analyzed in cell lines. The mechanism of TNC on modulating cancer cell apoptosis and drug resistant through activation of ERK1/2/NF-κB/p65 signals was evaluated. The effect of TNC on regulating cell cycle distribution was also tested. TNC, ERK1/2/p-ERK1/2, and apoptotic regulatory proteins Bcl-xL and Bcl-2 were highly expressed in human pancreatic cancer tissues. In vitro, exogenous TNC promoted pancreatic cancer cell growth also mediates basal as well as starved and drug-induced apoptosis in pancreatic cancer cells. The effects of TNC on anti-apoptosis were induced by the activation state of ERK1/2/NF-κB/p65 signals in pancreatic cell. TNC phosphorylate ERK1/2 to induce NF-κB/p65 nucleus translocation. The latter contributes to promote Bcl-xL, Bcl-2 protein expressions and reduce caspase activity, which inhibit cell apoptotic

Haloperidol Abrogates Matrix Metalloproteinase-9 Expression by Inhibition of NF-κB Activation in Stimulated Human Monocytic Cells

Directory of Open Access Journals (Sweden)

Yueh-Lun Lee

2018-01-01

Full Text Available Much evidence has indicated that matrix metalloproteinases (MMPs participate in the progression of neuroinflammatory disorders. The present study was undertaken to investigate the inhibitory effect and mechanism of the antipsychotic haloperidol on MMP activation in the stimulated THP-1 monocytic cells. Haloperidol exerted a strong inhibition on tumor necrosis factor- (TNF- α-induced MMP-9 gelatinolysis of THP-1 cells. A concentration-dependent inhibitory effect of haloperidol was observed in TNF-α-induced protein and mRNA expression of MMP-9. On the other hand, haloperidol slightly affected cell viability and tissue inhibition of metalloproteinase-1 levels. It significantly inhibited the degradation of inhibitor-κB-α (IκBα in activated cells. Moreover, it suppressed activated nuclear factor-κB (NF-κB detected by a mobility shift assay, NF-κB reporter gene, and chromatin immunoprecipitation analyses. Consistent with NF-κB inhibition, haloperidol exerted a strong inhibition of lipopolysaccharide- (LPS- induced MMP-9 gelatinolysis but not of transforming growth factor-β1-induced MMP-2. In in vivo studies, administration of haloperidol significantly attenuated LPS-induced intracerebral MMP-9 activation of the brain homogenate and the in situ in C57BL/6 mice. In conclusion, the selective anti-MMP-9 activation of haloperidol could possibly involve the inhibition of the NF-κB signal pathway. Hence, it was found that haloperidol treatment may represent a bystander of anti-MMP actions for its conventional psychotherapy.

Prevalence of bortezomib-resistant constitutive NF-kappaB activity in mantle cell lymphoma

Directory of Open Access Journals (Sweden)

Kahl Brad S

2008-05-01

Full Text Available Abstract Background The proteasome inhibitor bortezomib can inhibit activation of the transcription factor NF-κB, a mechanism implicated in its anti-neoplastic effects observed in mantle cell lymphoma (MCL. However, NF-κB can be activated through many distinct mechanisms, including proteasome independent pathways. While MCL cells have been shown to harbor constitutive NF-κB activity, what fraction of this activity in primary MCL samples is sensitive or resistant to inhibition by bortezomib remains unclear. Results Proteasome activity in the EBV-negative MCL cell lines Jeko-1 and Rec-1 is inhibited by greater than 80% after exposure to 20 nM bortezomib for 4 hours. This treatment decreased NF-κB activity in Jeko-1 cells, but failed to do so in Rec-1 cells when assessed by electrophoretic mobility shift assay (EMSA. Concurrently, Rec-1 cells were more resistant to the cytotoxic effects of bortezomib than Jeko-1 cells. Consistent with a proteasome inhibitor resistant pathway of activation described in mouse B-lymphoma cells (WEHI231 and a breast carcinoma cell line (MDA-MB-468, the bortezomib-resistant NF-κB activity in Rec-1 cells is inhibited by calcium chelators, calmodulin inhibitors, and perillyl alcohol, a monoterpene capable of blocking L-type calcium channels. Importantly, the combination of perillyl alcohol and bortezomib is synergistic in eliciting Rec-1 cell cytotoxicity. The relevance of these results is illuminated by the additional finding that a considerable fraction of primary MCL samples (8 out of 10 displayed bortezomib-resistant constitutive NF-κB activity. Conclusion Our findings show that bortezomib-resistant NF-κB activity is frequently observed in MCL samples and suggest that this activity may be relevant to MCL biology as well as serve as a potential therapeutic target.

Regorafenib inhibits tumor progression through suppression of ERK/NF-κB activation in hepatocellular carcinoma bearing mice.

Science.gov (United States)

Weng, Mao-Chi; Wang, Mei-Hui; Tsai, Jai-Jen; Kuo, Yu-Cheng; Liu, Yu-Chang; Hsu, Fei-Ting; Wang, Hsin-Ell

2018-03-13

Regorafenib has been demonstrated in our previous study to trigger apoptosis through suppression of extracellular signal-regulated kinase (ERK)/nuclear factor-κB (NF-κB) activation in hepatocellular carcinoma (HCC) SK-Hep1 cells in vitro However, the effect of regorafenib on NF-κB-modulated tumor progression in HCC in vivo is ambiguous. The aim of the present study is to investigate the effect of regorafenib on NF-κB-modulated tumor progression in HCC bearing mouse model. pGL4.50 luciferase reporter vector transfected SK-Hep1 (SK-Hep1/ luc2 ) and Hep3B 2.1-7 tumor bearing mice were established and used for this study. Mice were treated with vehicle or regorafenib (20 mg/kg/day by gavage) for 14 days. Effects of regorafenib on tumor growth and protein expression together with toxicity of regorafenib were evaluated with digital caliper and bioluminescence imaging (BLI), ex vivo Western blotting immunohistochemistry (IHC) staining, and measurement of body weight and pathological examination of liver tissue, respectively, in SK-Hep1/ luc2 and Hep3B 2.1-7 tumor bearing mice. The results indicated regorafenib significantly reduced tumor growth and expression of phosphorylated ERK, NF-κB p65 (Ser536), phosphorylated AKT and tumor progression-associated proteins. In addition, we found regorafenib induced both extrinsic and intrinsic apoptotic pathways. Body weight and liver morphology were not affected by regorafenib treatment. Our findings present the mechanism of tumor progression inhibition by regorafenib is linked to suppression of ERK/NF-κB signaling in SK-Hep1/ luc2 and Hep3B 2.1-7 tumor-bearing mice. ©2018 The Author(s).

Aloin Suppresses Lipopolysaccharide-Induced Inflammatory Response and Apoptosis by Inhibiting the Activation of NF-κB

Directory of Open Access Journals (Sweden)

Xuan Luo

2018-02-01

Full Text Available Numerous herbal-derived natural products are excellent anti-inflammatory agents. Several studies have reported that aloin, the major anthraquinone glycoside obtained from the Aloe species, exhibits anti-inflammatory activity. However, the molecular mechanism of this activity is not well understood. In this report, we found that aloin suppresses lipopolysaccharide-induced pro-inflammatory cytokine secretion and nitric oxide production, and downregulates the expression of tumor necrosis factor alpha (TNF-α, interleukin 6 (IL-6, inducible nitric oxide synthase (iNOS, and cyclooxygenase-2 (COX-2. Aloin inhibits the phosphorylation and acetylation of the NF-κB p65 subunit by suppressing the upstream kinases p38 and Msk1, preventing LPS-induced p65 translocation to the nucleus. We have also shown that aloin inhibits LPS-induced caspase-3 activation and apoptotic cell death. Collectively, these findings suggest that aloin effectively suppresses the inflammatory response, primarily through the inhibition of NF-κB signaling.

Investigations on GSK-3β/NF-kB signaling in stress and stress adaptive behavior in electric foot shock subjected mice.

Science.gov (United States)

Bali, Anjana; Jaggi, Amteshwar Singh

2016-04-01

The present study was designed to explore the role of GSK-3β and NF-kB signaling in electric foot shock-induced stress and stress adaptation. Mice were subjected to foot shocks of 0.5mA intensity and 1s duration of 1h to produce acute stress. Animals were exposed to the same stressor for 5 days to induce stress adaptation. The behavioral alterations were assessed using the actophotometer, hole board, open field and social interaction tests. The serum corticosterone levels were assessed as a marker of the HPA axis. The levels of total GSK-3β, p-GSK-3β-S9 and p-NF-kB were determined in the hippocampus, frontal cortex and amygdala. Acute electric foot shock stress produced behavioral and biochemical changes; decreased the levels of p-GSK-3β-S9, produced no change in total GSK-3β levels and increased p-NF-kB levels in the brain. However, repeated exposure of foot shock stress restored the behavioral and biochemical changes along with normalization of p-GSK-3β-S9 and p-NF-kB levels. Administration of AR-A01, a selective GSK-3β inhibitor, or diethyldithiocarbamic acid (DDTC), a selective NF-kB inhibitor, diminished acute stress-induced behavioral and biochemical changes. Furthermore, AR-A014418 normalized acute stress-induced alterations in p-GSK-3β-S9 and p-NF-kB levels, however, DDTC selectively restored NF-kB levels without any change in p-GSK-3β-S9 levels. It probably suggests that NF-kB is a downstream mediator of the GSK-3 signaling cascade. It may conclude that acute stress associated decrease in p-GSK-3β-S9 and increase in p-NF-kB levels in the brain contribute in the development of behavioral and biochemical alterations and normalization of GSK-3β/NF-kB signaling may contribute in stress adaptive behavior in response to repeated electric foot shock-subjected mice. Copyright © 2016 Elsevier B.V. All rights reserved.

Epithelial cells detect functional type III secretion system of enteropathogenic Escherichia coli through a novel NF-κB signaling pathway.

Directory of Open Access Journals (Sweden)

Yael Litvak

2017-07-01

Full Text Available Enteropathogenic Escherichia coli (EPEC, a common cause of infant diarrhea, is associated with high risk of mortality in developing countries. The primary niche of infecting EPEC is the apical surface of intestinal epithelial cells. EPEC employs a type three secretion system (TTSS to inject the host cells with dozens of effector proteins, which facilitate attachment to these cells and successful colonization. Here we show that EPEC elicit strong NF-κB activation in infected host cells. Furthermore, the data indicate that active, pore-forming TTSS per se is necessary and sufficient for this NF-κB activation, regardless of any specific effector or protein translocation. Importantly, upon infection with wild type EPEC this NF-κB activation is antagonized by anti-NF-κB effectors, including NleB, NleC and NleE. Accordingly, this NF-κB activation is evident only in cells infected with EPEC mutants deleted of nleB, nleC, and nleE. The TTSS-dependent NF-κB activation involves a unique pathway, which is independent of TLRs and Nod1/2 and converges with other pathways at the level of TAK1 activation. Taken together, our results imply that epithelial cells have the capacity to sense the EPEC TTSS and activate NF-κB in response. Notably, EPEC antagonizes this capacity by delivering anti-NF-κB effectors into the infected cells.

Delphinidin, a specific inhibitor of histone acetyltransferase, suppresses inflammatory signaling via prevention of NF-κB acetylation in fibroblast-like synoviocyte MH7A cells

International Nuclear Information System (INIS)

Seong, Ah-Reum; Yoo, Jung-Yoon; Choi, KyungChul; Lee, Mee-Hee; Lee, Yoo-Hyun; Lee, Jeongmin; Jun, Woojin; Kim, Sunoh; Yoon, Ho-Geun

2011-01-01

Highlights: → Delphinidin is a novel inhibitor of p300/CBP histone acetyltransferase. → Delphinidin prevents the hyperacetylation of p65 by inhibiting the HAT activity of p300/CBP. → Delphinidin efficiently suppresses the expression of inflammatory cytokines in MH7A cells via hypoacetylation of NF-κB. → Delphinidin inhibits cytokine release in the Jurkat T lymphocyte cell line. -- Abstract: Histone acetyltransferase (HAT) inhibitors (HATi) isolated from dietary compounds have been shown to suppress inflammatory signaling, which contributes to rheumatoid arthritis. Here, we identified a novel HATi in Punica granatum L. known as delphinidin (DP). DP did not affect the activity of other epigenetic enzymes (histone deacetylase, histone methyltransferase, or sirtuin1). DP specifically inhibited the HAT activities of p300/CBP. It also inhibited p65 acetylation in MH7A cells, a human rheumatoid arthritis synovial cell line. DP-induced hypoacetylation was accompanied by cytosolic accumulation of p65 and nuclear localization of IKBα. Accordingly, DP treatment inhibited TNFα-stimulated increases in NF-κB function and expression of NF-κB target genes in these cells. Importantly, DP suppressed lipopolysaccharide-induced pro-inflammatory cytokine expression in Jurkat T lymphocytes, demonstrating that HATi efficiently suppresses cytokine-mediated immune responses. Together, these results show that the HATi activity of DP counters anti-inflammatory signaling by blocking p65 acetylation and that this compound may be useful in preventing inflammatory arthritis.

Delphinidin, a specific inhibitor of histone acetyltransferase, suppresses inflammatory signaling via prevention of NF-{kappa}B acetylation in fibroblast-like synoviocyte MH7A cells

Energy Technology Data Exchange (ETDEWEB)

Seong, Ah-Reum; Yoo, Jung-Yoon; Choi, KyungChul [Department of Biochemistry and Molecular Biology, Center for Chronic Metabolic Disease Research, College of Medicine, Yonsei University, Seoul (Korea, Republic of); Lee, Mee-Hee [Department of Biochemistry and Molecular Biology, Center for Chronic Metabolic Disease Research, College of Medicine, Yonsei University, Seoul (Korea, Republic of); Brain Korea 21 Project for Medical Sciences, Yonsei University, College of Medicine, Seoul (Korea, Republic of); Lee, Yoo-Hyun [Department of Food Science and Nutrition, The University of Suwon, Kyunggi-do (Korea, Republic of); Lee, Jeongmin [Department of Medical Nutrition, Kyung Hee University, Kyunggi-do (Korea, Republic of); Jun, Woojin [Department of Food and Nutrition, Chonnam National University, Gwangju (Korea, Republic of); Kim, Sunoh, E-mail: sunoh@korea.ac.kr [Jeollanamdo Institute of Natural Resources Research, Jeonnam (Korea, Republic of); Yoon, Ho-Geun, E-mail: yhgeun@yuhs.ac [Department of Biochemistry and Molecular Biology, Center for Chronic Metabolic Disease Research, College of Medicine, Yonsei University, Seoul (Korea, Republic of); Brain Korea 21 Project for Medical Sciences, Yonsei University, College of Medicine, Seoul (Korea, Republic of)

2011-07-08

Highlights: {yields} Delphinidin is a novel inhibitor of p300/CBP histone acetyltransferase. {yields} Delphinidin prevents the hyperacetylation of p65 by inhibiting the HAT activity of p300/CBP. {yields} Delphinidin efficiently suppresses the expression of inflammatory cytokines in MH7A cells via hypoacetylation of NF-{kappa}B. {yields} Delphinidin inhibits cytokine release in the Jurkat T lymphocyte cell line. -- Abstract: Histone acetyltransferase (HAT) inhibitors (HATi) isolated from dietary compounds have been shown to suppress inflammatory signaling, which contributes to rheumatoid arthritis. Here, we identified a novel HATi in Punica granatum L. known as delphinidin (DP). DP did not affect the activity of other epigenetic enzymes (histone deacetylase, histone methyltransferase, or sirtuin1). DP specifically inhibited the HAT activities of p300/CBP. It also inhibited p65 acetylation in MH7A cells, a human rheumatoid arthritis synovial cell line. DP-induced hypoacetylation was accompanied by cytosolic accumulation of p65 and nuclear localization of IKB{alpha}. Accordingly, DP treatment inhibited TNF{alpha}-stimulated increases in NF-{kappa}B function and expression of NF-{kappa}B target genes in these cells. Importantly, DP suppressed lipopolysaccharide-induced pro-inflammatory cytokine expression in Jurkat T lymphocytes, demonstrating that HATi efficiently suppresses cytokine-mediated immune responses. Together, these results show that the HATi activity of DP counters anti-inflammatory signaling by blocking p65 acetylation and that this compound may be useful in preventing inflammatory arthritis.

Overexpression of the transcription factor NF-YC9 confers abscisic acid hypersensitivity in Arabidopsis.

Science.gov (United States)

Bi, Chao; Ma, Yu; Wang, Xiao-Fang; Zhang, Da-Peng

2017-11-01

Nuclear factor Y (NF-Y) family proteins are involved in many developmental processes and responses to environmental cues in plants, but whether and how they regulate phytohormone abscisic acid (ABA) signaling need further studies. In the present study, we showed that over-expression of the NF-YC9 gene confers ABA hypersensitivity in both the early seedling growth and stomatal response, while down-regulation of NF-YC9 does not affect ABA response in these processes. We also showed that over-expression of the NF-YC9 gene confers salt and osmotic hypersensitivity in early seedling growth, which is likely to be directly associated with the ABA hypersensitivity. Further, we observed that NF-YC9 physically interacts with the ABA-responsive bZIP transcription factor ABA-INSENSITIVE5 (ABI5), and facilitates the function of ABI5 to bind and activate the promoter of a target gene EM6. Additionally, NF-YC9 up-regulates expression of the ABI5 gene in response to ABA. These findings show that NF-YC9 may be involved in ABA signaling as a positive regulator and likely functions redundantly together with other NF-YC members, and support the model that the NF-YC9 mediates ABA signaling via targeting to and aiding the ABA-responsive transcription factors such as ABI5.

Synergistic activation of NF-κB by nontypeable H. influenzae and S. pneumoniae is mediated by CK2, IKKβ-IκBα, and p38 MAPK

International Nuclear Information System (INIS)

Kweon, Soo-Mi; Wang, Beinan; Rixter, Davida; Lim, Jae Hyang; Koga, Tomoaki; Ishinaga, Hajime; Chen, L.-F.; Jono, Hirofumi; Xu Haidong; Li, J.-D.

2006-01-01

In review of the past studies on NF-κB regulation, most of them have focused on investigating how NF-κB is activated by a single inducer at a time. Given the fact that, in mixed bacterial infections in vivo, multiple inflammation inducers, including both nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae, are present simultaneously, a key issue that has yet to be addressed is whether NTHi and S. pneumoniae simultaneously activate NF-κB and the subsequent inflammatory response in a synergistic manner. Here, we show that NTHi and S. pneumoniae synergistically induce NF-κB-dependent inflammatory response via activation of multiple signaling pathways in vitro and in vivo. The classical IKKβ-IκBα and p38 MAPK pathways are involved in synergistic activation of NF-κB via two distinct mechanisms, p65 nuclear translocation-dependent and -independent mechanisms. Moreover, casein kinase 2 (CK2) is involved in synergistic induction of NF-κB via a mechanism dependent on phosphorylation of p65 at both Ser536 and Ser276 sites. These studies bring new insights into the molecular mechanisms underlying the NF-κB-dependent inflammatory response in polymicrobial infections and may lead to development of novel therapeutic strategies for modulating inflammation in mixed infections for patients with otitis media and chronic obstructive pulmonary diseases

The function of DREAM gene mediated by NF-kB signal pathway in the pathogenesis of osteosarcoma.

Science.gov (United States)

Qian, Jize; Lv, Mingbo; Zhang, Wenbo

2017-01-01

To explore the function of DREAM gene mediated by NF-kB signal pathway in the pathogenesis of osteosarcoma. This study included 13 Sprague Dawley (SD) rats with osteosarcoma (treatment group) and 13 healthy rats (control group). NF-kB, DREAM and P105 mRNAs expression levels were determined using quantitative PCR (qPCR). The expression levels of NF-kB, DREAM and P105 proteins were evaluated using ELISA and western blot. Also, DREAM protein expression in rats was determined by immunofluorescence. NF-kB and DREAM levels in the treatment group were significantly higher than those in the control group (pkB and DREAM expression levels in the treatment group were significantly higher than in the control group (pkB and DREAM levels in the treatment group were 4.3±0.12 μg/l and 6.8±0.21 μg/l, respectively. These levels in the control group were 0.96±0.11 μg/l and 1.25±0.18 μg/l, respectively. P105 expression level in the treatment group was 0.37±0.11 μg/l which was significantly lower than that in the control group (1.63±0.21 μg/l) (pkB signal pathway promoted the expression of DREAM gene and also promoted the pathogenesis and worsening of osteosarcoma.

Baicalin Inhibits Lipopolysaccharide-Induced Inflammation Through Signaling NF-κB Pathway in HBE16 Airway Epithelial Cells.

Science.gov (United States)

Dong, Shou-jin; Zhong, Yun-qing; Lu, Wen-ting; Li, Guan-hong; Jiang, Hong-li; Mao, Bing

2015-08-01

Baicalin, a flavonoid monomer derived from Scutellaria baicalensis called Huangqin in mandarin, is the main active ingredient contributing to S. baicalensis' efficacy. It is known in China that baicalin has potential therapeutic effects on inflammatory diseases. However, its anti-inflammatory mechanism has still not been fully interpreted. We aim to investigate the anti-inflammatory effect of baicalin on lipopolysaccharide (LPS)-induced inflammation in HBE16 airway epithelial cells and also to explore the underlying signaling mechanisms. The anti-inflammatory action of baicalin was evaluated in human airway epithelial cells HBE16 treated with LPS. Airway epithelial cells HBE16 were pretreated with a range of concentrations of baicalin for 30 min and then stimulated with 10 μg/ml LPS. The secretions of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) in cell culture supernatants were quantified by enzyme-linked immunosorbent assay (ELISA). The messenger RNA (mRNA) expressions of IL-6, IL-8, and TNF-α were tested by quantitative real-time polymerase chain reaction (real-time RT-PCR). Furthermore, Western blotting was used to determine whether the signaling pathway NF-κB was involved in the anti-inflammatory action of baicalin. The inflammatory cell model was successfully built with 10 μg/ml LPS for 24 h in our in vitro experiments. Both the secretions and the mRNA expressions of IL-6, IL-8, and TNF-α were significantly inhibited by baicalin. Moreover, the expression levels of phospho-IKKα/β and phospho-NF-κB p65 were downregulated, and the phospho-IκB-α level was upregulated by baicalin. These findings suggest that the anti-inflammatory properties of baicalin may be resulted from the inhibition of IL-6, IL-8, and TNF-α expression via preventing signaling NF-κB pathway in HBE16 airway epithelial cells. In addition, this study provides evidence to understand the therapeutic effects of baicalin on inflammatory diseases in

Diclofenac enhances proinflammatory cytokine-induced nitric oxide production through NF-κB signaling in cultured astrocytes

International Nuclear Information System (INIS)

Kakita, Hiroki; Aoyama, Mineyoshi; Hussein, Mohamed Hamed; Kato, Shin; Suzuki, Satoshi; Ito, Tetsuya; Togari, Hajime; Asai, Kiyofumi

2009-01-01

Recently, the number of reports of encephalitis/encephalopathy associated with influenza virus has increased. In addition, the use of a non-steroidal anti-inflammatory drug, diclofenac sodium (DCF), is associated with a significant increase in the mortality rate of influenza-associated encephalopathy. Activated astrocytes are a source of nitric oxide (NO), which is largely produced by inducible NO synthase (iNOS) in response to proinflammatory cytokines. Therefore, we investigated whether DCF enhances nitric oxide production in astrocytes stimulated with proinflammatory cytokines. We stimulated cultured rat astrocytes with three cytokines, interleukin-1β, tumor necrosis factor-α and interferon-γ, and then treated the astrocytes with DCF or acetaminophen (N-acetyl-p-aminophenol: APAP). iNOS and NO production in astrocyte cultures were induced by proinflammatory cytokines. The addition of DCF augmented NO production, but the addition of APAP did not. NF-κB inhibitors SN50 and MG132 inhibited iNOS gene expression in cytokine-stimulated astrocytes with or without DCF. Similarly, NF-κB p65 Stealth small interfering RNA suppressed iNOS gene expression in cytokine-stimulated astrocytes with or without DCF. LDH activity and DAPI staining showed that DCF induces cell damage in cytokine-stimulated astrocytes. An iNOS inhibitor, L-NMMA, inhibited the cytokine- and DCF-induced cell damage. In conclusion, this study demonstrates that iNOS and NO are induced in astrocyte cultures by proinflammatory cytokines. Addition of DCF further augments NO production. This effect is mediated via NF-κB signaling and leads to cell damage. The enhancement of DCF on NO production may explain the significant increase in the mortality rate of influenza-associated encephalopathy in patients treated with DCF.

B-cell-intrinsic hepatitis C virus expression leads to B-cell-lymphomagenesis and induction of NF-κB signalling.

Directory of Open Access Journals (Sweden)

Yuri Kasama

Full Text Available Hepatitis C virus (HCV infection leads to the development of hepatic diseases, as well as extrahepatic disorders such as B-cell non-Hodgkin's lymphoma (B-NHL. To reveal the molecular signalling pathways responsible for HCV-associated B-NHL development, we utilised transgenic (Tg mice that express the full-length HCV genome specifically in B cells and develop non-Hodgkin type B-cell lymphomas (BCLs. The gene expression profiles in B cells from BCL-developing HCV-Tg mice, from BCL-non-developing HCV-Tg mice, and from BCL-non-developing HCV-negative mice were analysed by genome-wide microarray. In BCLs from HCV-Tg mice, the expression of various genes was modified, and for some genes, expression was influenced by the gender of the animals. Markedly modified genes such as Fos, C3, LTβR, A20, NF-κB and miR-26b in BCLs were further characterised using specific assays. We propose that activation of both canonical and alternative NF-κB signalling pathways and down-regulation of miR-26b contribute to the development of HCV-associated B-NHL.

The oncoprotein gankyrin interacts with RelA and suppresses NF-κB activity

International Nuclear Information System (INIS)

Higashitsuji, Hiroaki; Higashitsuji, Hisako; Liu, Yu; Masuda, Tomoko; Fujita, Takanori; Abdel-Aziz, H. Ismail; Kongkham, Supranee; Dawson, Simon; John Mayer, R.; Itoh, Yoshito; Sakurai, Toshiharu; Itoh, Katsuhiko; Fujita, Jun

2007-01-01

Gankyrin is an oncoprotein commonly overexpressed in hepatocellular carcinomas. It interacts with multiple proteins and accelerates degradation of tumor suppressors Rb and p53. Since gankyrin consists of 7 ankyrin repeats and is structurally similar to IκBs, we investigated its interaction with NF-κB. We found that gankyrin directly binds to RelA. In HeLa and 293 cells, overexpression of gankyrin suppressed the basal as well as TNFα-induced transcriptional activity of NF-κB, whereas down-regulation of gankyrin increased it. Gankyrin did not affect the NF-κB DNA-binding activity or nuclear translocation of RelA induced by TNFα in these cells. Leptomycin B that inhibits nuclear export of RelA suppressed the NF-κB activity, which was further suppressed by gankyrin. The inhibitory effect of gankyrin was abrogated by nicotinamide as well as down-regulation of SIRT1, a class III histone deacetylase. Thus, gankyrin binds to NF-κB and suppresses its activity at the transcription level by modulating acetylation via SIRT1

Myelin activates FAK/Akt/NF-kappaB pathways and provokes CR3-dependent inflammatory response in murine system.

Directory of Open Access Journals (Sweden)

Xin Sun

2010-02-01

Full Text Available Inflammatory response following central nervous system (CNS injury contributes to progressive neuropathology and reduction in functional recovery. Axons are sensitive to mechanical injury and toxic inflammatory mediators, which may lead to demyelination. Although it is well documented that degenerated myelin triggers undesirable inflammatory responses in autoimmune diseases such as multiple sclerosis (MS and its animal model, experimental autoimmune encephalomyelitis (EAE, there has been very little study of the direct inflammatory consequences of damaged myelin in spinal cord injury (SCI, i.e., there is no direct evidence to show that myelin debris from injured spinal cord can trigger undesirable inflammation in vitro and in vivo. Our data showed that myelin can initiate inflammatory responses in vivo, which is complement receptor 3 (CR3-dependent via stimulating macrophages to express pro-inflammatory molecules and down-regulates expression of anti-inflammatory cytokines. Mechanism study revealed that myelin-increased cytokine expression is through activation of FAK/PI3K/Akt/NF-kappaB signaling pathways and CR3 contributes to myelin-induced PI3K/Akt/NF-kappaB activation and cytokine production. The myelin induced inflammatory response is myelin specific as sphingomyelin (the major lipid of myelin and myelin basic protein (MBP, one of the major proteins of myelin are not able to activate NF-kappaB signaling pathway. In conclusion, our results demonstrate a crucial role of myelin as an endogenous inflammatory stimulus that induces pro-inflammatory responses and suggest that blocking myelin-CR3 interaction and enhancing myelin debris clearance may be effective interventions for treating SCI.

Root Extract of Polygonum cuspidatum Siebold & Zucc. Ameliorates DSS-Induced Ulcerative Colitis by Affecting NF-kappaB Signaling Pathway in a Mouse Model via Synergistic Effects of Polydatin, Resveratrol, and Emodin

Directory of Open Access Journals (Sweden)

Baohai Liu

2018-04-01

Full Text Available Background:Polygonum cuspidatum Siebold & Zucc. (PCS has antibacterial properties and may prevent Ulcerative colitis (UC but related molecular mechanism remains unknown. NF-κB signaling pathway is associated with inflammatory responses and its inactivation may be critical for effective therapy of UC.Methods: UC mouse (C57BL/6J model was established by using dextran sulfate sodium (DSS. The extract of PCS (PCSE was prepared by using ethanol and its main ingredients were measured by HPLC. Thirty-two UC mice were evenly assigned into DG (received vehicle control, LG (0.1 g/kg PCSE daily, MG (0.2 g/kg PCSE daily and HG (0.4 g/kg PCSE daily groups. Meanwhile, 8 healthy mice were assigned as a control group (CG. Serum pharmacokinetics of PCS was measured by using HPLC. After 8-day treatment, weight, colon length and disease activity index (DAI were measured. Inflammatory cytokines and oxidant biomarkers were measured by ELISA kits. The levels of cytokines, and key molecules in NF-κB pathway, were measured by using Western Blot. The effects of main ingredients of PCSE on cytokines and NF-κB signaling pathway were explored by using intestinal cells of a mouse UC model. The normality criterion was evaluated using the Saphiro–Wilk test. The quantitative variables were compared using the paired Student’s-t test.Results: The main ingredients of PCSE were polydatin, resveratrol and emodin. Polydatin may be transformed into resveratrol in the intestine of the mice. PCSE prevented DSS-caused weight loss and colon length reduction, and improved histopathology of UC mice (P < 0.05. PCSE treatment increased the serum levels of IL-10 and reduced the levels of IL-1 beta, IL-6 and TNF-α (P < 0.05. PCSE increased the activities of SOD, CAT, GPX and reduced the level of MDA, BCL-2, beta-arrestin, NF-κB p65 and the activity of MPO (P < 0.05. The combination of polydatin, resveratrol or emodin, and or PCSE exhibited higher inhibitory activities for cytokines

NF-kappaB: Two Sides of the Same Coin.

Science.gov (United States)

Pires, Bruno R B; Silva, Rafael C M C; Ferreira, Gerson M; Abdelhay, Eliana

2018-01-09

Nuclear Factor-kappa B (NF-κB) is a transcription factor family that regulates a large number of genes that are involved in important physiological processes, including survival, inflammation, and immune responses. More recently, constitutive expression of NF-κB has been associated with several types of cancer. In addition, microorganisms, such as viruses and bacteria, cooperate in the activation of NF-κB in tumors, confirming the multifactorial role of this transcription factor as a cancer driver. Recent reports have shown that the NF-κB signaling pathway should receive attention for the development of therapies. In addition to the direct effects of NF-κB in cancer cells, it might also impact immune cells that can both promote or prevent tumor development. Currently, with the rise of cancer immunotherapy, the link among immune cells, inflammation, and cancer is a major focus, and NF-κB could be an important regulator for the success of these therapies. This review discusses the contrasting roles of NF-κB as a regulator of pro- and antitumor processes and its potential as a therapeutic target.

Gnotobiotic IL-10; NF-kappaB mice develop rapid and severe colitis following Campylobacter jejuni infection.

Directory of Open Access Journals (Sweden)

Elisabeth Lippert

2009-10-01

Full Text Available Limited information is available on the molecular mechanisms associated with Campylobacter jejuni (C. jejuni induced food-borne diarrheal illnesses. In this study, we investigated the function of TLR/NF-kappaB signaling in C. jejuni induced pathogenesis using gnotobiotic IL-10(-/-; NF-kappaB(EGFP mice. In vitro analysis showed that C. jejuni induced IkappaB phosphorylation, followed by enhanced NF-kappaB transcriptional activity and increased IL-6, MIP-2alpha and NOD2 mRNA accumulation in infected-mouse colonic epithelial cells CMT93. Importantly, these events were blocked by molecular delivery of an IkappaB inhibitor (Ad5IkappaBAA. NF-kappaB signalling was also important for C.jejuni-induced cytokine gene expression in bone marrow-derived dendritic cells. Importantly, C. jejuni associated IL-10(-/-; NF-kappaB(EGFP mice developed mild (day 5 and severe (day 14 ulcerating colonic inflammation and bloody diarrhea as assessed by colonoscopy and histological analysis. Macroscopic analysis showed elevated EGFP expression indicating NF-kappaB activation throughout the colon of C. jejuni associated IL-10(-/-; NF-kappaB(EGFP mice, while fluorescence microscopy revealed EGFP positive cells to be exclusively located in lamina propria mononuclear cells. Pharmacological NF-kappaB inhibition using Bay 11-7085 did not ameliorate C. jejuni induced colonic inflammation. Our findings indicate that C. jejuni induces rapid and severe intestinal inflammation in a susceptible host that correlates with enhanced NF-kappaB activity from lamina propria immune cells.

Transglutaminase 2 gene ablation protects against renal ischemic injury by blocking constant NF-κB activation

International Nuclear Information System (INIS)

Kim, Dae-Seok; Kim, Bora; Tahk, Hongmin; Kim, Dong-Hyun; Ahn, Eu-Ree; Choi, Changsun; Jeon, Yoon; Park, Seo Young; Lee, Ho; Oh, Seung Hyun; Kim, Soo-Youl

2010-01-01

Research highlights: → No acute renal tubular necrotic lesions were found in TGase2 -/- mice with ischemic kidney injury. → NF-κB activation is reduced in TGase2 -/- mice with ischemic kidney injury. → Hypoxic stress did not increase NF-κB activity in MEFs from TGase2 -/- mice. → COX-2 induction is suppressed in TGase2 -/- mice with ischemic kidney injury. -- Abstract: Transglutaminase 2 knockout (TGase2 -/- ) mice show significantly reduced inflammation with decreased myofibroblasts in a unilateral ureteral obstruction (UUO) model, but the mechanism remains to be clarified. Nuclear factor-κB (NF-κB) activation plays a major role in the progression of inflammation in an obstructive nephropathy model. However, the key factors extending the duration of NF-κB activation in UUO are not known. In several inflammatory diseases, we and others recently found that TGase 2 plays a key role in extending NF-κB activation, which contributes to the pathogenesis of disease. In the current study, we found that NF-κB activity in mouse embryogenic fibroblasts (MEFs) from TGase2 -/- mice remained at the control level while the NF-κB activity of wild-type (WT) MEFs was highly increased under hypoxic stress. Using the obstructive nephropathy model, we found that NF-κB activity remained at the control level in TGase2 -/- mouse kidney tissues, as measured by COX-2 expression, but was highly increased in WT tissues. We conclude that TGase 2 gene ablation reduces the duration of NF-κB activation in ischemic injury.

The MC160 Protein Expressed by the Dermatotropic Poxvirus Molluscum Contagiosum Virus Prevents Tumor Necrosis Factor Alpha-Induced NF-κB Activation via Inhibition of I Kappa Kinase Complex Formation

Science.gov (United States)

Nichols, Daniel Brian; Shisler, Joanna L.

2006-01-01

The pluripotent cytokine tumor necrosis factor alpha (TNF-α) binds to its cognate TNF receptor I (TNF-RI) to stimulate inflammation via activation of the NF-κB transcription factor. To prevent the detrimental effects of TNF-α in keratinocytes infected with the molluscum contagiosum virus (MCV), this poxvirus is expected to produce proteins that block at least one step of the TNF-RI signal transduction pathway. One such product, the MC160 protein, is predicted to interfere with this cellular response because of its homology to other proteins that regulate TNF-RI-mediated signaling. We report here that expression of MC160 molecules did significantly reduce TNF-α-mediated NF-κB activation in 293T cells, as measured by gene reporter and gel mobility shift assays. Since we observed that MC160 decreased other NF-κB activation pathways, namely those activated by receptor-interacting protein, TNF receptor-associated factor 2, NF-κB-inducing kinase, or MyD88, we hypothesized that the MC160 product interfered with I kappa kinase (IKK) activation, an event common to multiple signal transduction pathways. Indeed, MC160 protein expression was associated with a reduction in in vitro IKK kinase activity and IKK subunit phosphorylation. Further, IKK1-IKK2 interactions were not detected in MC160-expressing cells, under conditions demonstrated to induce IKK complex formation, but interactions between the MC160 protein and the major IKK subunits were undetectable. Surprisingly, MC160 expression correlated with a decrease in IKK1, but not IKK2 levels, suggesting a mechanism for MC160 disruption of IKK1-IKK2 interactions. MCV has probably retained its MC160 gene to inhibit NF-κB activation by interfering with signaling via multiple biological mediators. In the context of an MCV infection in vivo, MC160 protein expression may dampen the cellular production of proinflammatory molecules and enhance persistent infections in host keratinocytes. PMID:16378960

URG4/URGCP enhances the angiogenic capacity of human hepatocellular carcinoma cells in vitro via activation of the NF-κB signaling pathway

International Nuclear Information System (INIS)

Xing, Sizhong; Zhang, Bing; Hua, Ruixi; Tai, William Chi-shing; Zeng, Zhirong; Xie, Binhui; Huang, Chenghui; Xue, Jisu; Xiong, Shiqiu; Yang, Jianyong; Liu, Side; Li, Heping

2015-01-01

Angiogenesis is essential for tumor growth. Hepatocellular carcinoma (HCC) is characterized by hypervascularity; high levels of angiogenesis are associated with poor prognosis and a highly invasive phenotype in HCC. Up-regulated gene-4 (URG4), also known as upregulator of cell proliferation (URGCP), is overexpressed in multiple tumor types and has been suggested to act as an oncogene. This study aimed to elucidate the effect of URG4/URGCP on the angiogenic capacity of HCC cells in vitro. Expression of URG4/URGCP in HCC cell lines and normal liver epithelial cell lines was examined by Western blotting and quantitative real-time PCR. URG4/URGCP was stably overexpressed or transiently knocked down using a shRNA in two HCC cell lines. The human umbilical vein endothelial cell (HUVEC) tubule formation and Transwell migration assays and chicken chorioallantoic membrane (CAM) assay were used to examine the angiogenic capacity of conditioned media from URG4/URGCP-overexpressing and knockdown cells. A luciferase reporter assay was used to examine the transcriptional activity of nuclear factor kappa – light – chain - enhancer of activated B cells (NF-κB). NF-κB was inhibited by overexpressing degradation-resistant mutant inhibitor of κB (IκB)-α. Expression of vascular endothelial growth factor C (VEGFC), tumor necrosis factor-α (TNFα), interleukin (IL)-6, IL-8 and v-myc avian myelocytomatosis viral oncogene homolog (MYC) were examined by quantitative real-time PCR; VEGFC protein expression was analyzed using an ELISA. URG4/URGCP protein and mRNA expression were significantly upregulated in HCC cell lines. Overexpressing URG4/URGCP enhanced - while silencing URG4/URGCP decreased - the capacity of HCC cell conditioned media to induce HUVEC tubule formation and migration and neovascularization in the CAM assay. Furthermore, overexpressing URG4/URGCP increased - whereas knockdown of URG4/URGCP decreased - VEGFC expression, NF-κB transcriptional activity, the levels

Bee Venom Inhibits Porphyromonas gingivalis Lipopolysaccharides-Induced Pro-Inflammatory Cytokines through Suppression of NF-κB and AP-1 Signaling Pathways.

Science.gov (United States)

Kim, Woon-Hae; An, Hyun-Jin; Kim, Jung-Yeon; Gwon, Mi-Gyeong; Gu, Hyemin; Park, Jae-Bok; Sung, Woo Jung; Kwon, Yong-Chul; Park, Kyung-Duck; Han, Sang Mi; Park, Kwan-Kyu

2016-11-10

Periodontitis is a chronic inflammatory disease that leads to destruction of tooth supporting tissues. Porphyromonas gingivalis ( P. gingivalis ), especially its lipopolysaccharides (LPS), is one of major pathogens that cause periodontitis. Bee venom (BV) has been widely used as a traditional medicine for various diseases. Previous studies have demonstrated the anti-inflammatory, anti-bacterial effects of BV. However, a direct role and cellular mechanism of BV on periodontitis-like human keratinocytes have not been explored. Therefore, we investigated the anti-inflammatory mechanism of BV against P. gingivalis LPS (PgLPS)-induced HaCaT human keratinocyte cell line. The anti-inflammatory effect of BV was demonstrated by various molecular biological methods. The results showed that PgLPS increased the expression of Toll-like receptor (TLR)-4 and pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, and interferon (IFN)-γ. In addition, PgLPS induced activation of the signaling pathways of inflammatory cytokines-related transcription factors, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein 1 (AP-1). BV effectively inhibited those pro-inflammatory cytokines through suppression of NF-κB and AP-1 signaling pathways. These results suggest that administration of BV attenuates PgLPS-induced inflammatory responses. Furthermore, BV may be a useful treatment to anti-inflammatory therapy for periodontitis.

Antitumor Activity of Portulaca Oleracea L. Polysaccharide on HeLa Cells Through Inducing TLR4/NF-κB Signaling.

Science.gov (United States)

Zhao, Rui; Zhang, Tao; Ma, Baoling; Li, Xing

2017-01-01

Abstarct We have previously shown that Portulaca oleracea L. polysaccharide (POL-P3b) possesses the ability to inhibit cervical cancer cell growth in vitro and in vivo. In this study, we explored how toll-like receptor 4 (TLR4) signaling correlated with the antitumor mechanism of POL-P3b. Western blotting was utilized to detect the expression of TLR4 and the downstream signaling pathway. The level of inflammatory mediator was quantified using enzyme-linked immunosorbent assay (ELISA) kits. The effects of POL-P3b on the proliferation and apoptosis in HeLa cells were determined by WST-8 assay and Hoechst 33342/propidium iodide (PI) assay. Our results demonstrated that lipopolysaccharide (LPS) binding to TLR4 on tumor cells could enhance HeLa cell proliferation and increase the expression of TLR4 and the downstream molecules. Treating HeLa cells with POL-P3b could decrease the proliferation of HeLa cells, and upregulate Bax level and downregulate Bcl-2 level in a concentration-dependent manner. In addition, POL-P3b inhibited the protein expression levels of TLR4, MyD88, TRAF6, Activator Protein-1 (AP-1) and nuclear factor-κB (NF-κB) subunit P65 in HeLa cells. Furthermore, POL-P3b also reduced the production of cytokine/chemokine. Taken together, the present work suggested the antitumor mechanism of POL-P3b by downregulating TLR4 downstream signaling pathway and inducing cell apoptosis. Our results may provide direct evidence to suggest that POL-P3b should be considered as a potent nutrient supplement for oncotherapy.

Genetic diversity of EBV-encoded LMP1 in the Swiss HIV Cohort Study and implication for NF-Κb activation.

Directory of Open Access Journals (Sweden)

Emilie Zuercher

Full Text Available Epstein-Barr virus (EBV is associated with several types of cancers including Hodgkin's lymphoma (HL and nasopharyngeal carcinoma (NPC. EBV-encoded latent membrane protein 1 (LMP1, a multifunctional oncoprotein, is a powerful activator of the transcription factor NF-κB, a property that is essential for EBV-transformed lymphoblastoid cell survival. Previous studies reported LMP1 sequence variations and induction of higher NF-κB activation levels compared to the prototype B95-8 LMP1 by some variants. Here we used biopsies of EBV-associated cancers and blood of individuals included in the Swiss HIV Cohort Study (SHCS to analyze LMP1 genetic diversity and impact of sequence variations on LMP1-mediated NF-κB activation potential. We found that a number of variants mediate higher NF-κB activation levels when compared to B95-8 LMP1 and mapped three single polymorphisms responsible for this phenotype: F106Y, I124V and F144I. F106Y was present in all LMP1 isolated in this study and its effect was variant dependent, suggesting that it was modulated by other polymorphisms. The two polymorphisms I124V and F144I were present in distinct phylogenetic groups and were linked with other specific polymorphisms nearby, I152L and D150A/L151I, respectively. The two sets of polymorphisms, I124V/I152L and F144I/D150A/L151I, which were markers of increased NF-κB activation in vitro, were not associated with EBV-associated HL in the SHCS. Taken together these results highlighted the importance of single polymorphisms for the modulation of LMP1 signaling activity and demonstrated that several groups of LMP1 variants, through distinct mutational paths, mediated enhanced NF-κB activation levels compared to B95-8 LMP1.

Suppression of NF-κB signaling and NLRP3 inflammasome activation in macrophages is responsible for the amelioration of experimental murine colitis by the natural compound fraxinellone

Energy Technology Data Exchange (ETDEWEB)

Wu, Xue-Feng; Ouyang, Zi-Jun; Feng, Li-Li; Chen, Gong; Guo, Wen-Jie; Shen, Yan; Wu, Xu-Dong; Sun, Yang, E-mail: yangsun@nju.edu.cn; Xu, Qiang, E-mail: molpharm@163.com

2014-11-15

Inflammatory bowel disease (IBD) affects millions of people worldwide. Although the etiology of this disease is uncertain, accumulating evidence indicates a key role for the activated mucosal immune system. In the present study, we examined the effects of the natural compound fraxinellone on dextran sulfate sodium (DSS)-induced colitis in mice, an animal model that mimics IBD. Treatment with fraxinellone significantly reduced weight loss and diarrhea in mice and alleviated the macroscopic and microscopic signs of the disease. In addition, the activities of myeloperoxidase and alkaline phosphatase were markedly suppressed, while the levels of glutathione were increased in colitis tissues following fraxinellone treatment. This compound also decreased the colonic levels of interleukin (IL)-1β, IL-6, IL-18 and tumor necrosis factor (TNF)-α in a concentration-dependent manner. These effects of fraxinellone in mice with experimental colitis were attributed to its inhibition of CD11b{sup +} macrophage infiltration. The mRNA levels of macrophage-related molecules in the colon, including intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2), were also markedly inhibited following fraxinellone treatment. The results from in vitro assays showed that fraxinellone significantly reduced lipopolysaccharide (LPS)-induced production of nitric oxide (NO), IL-1β and IL-18 as well as the activity of iNOS in both THP-1 cells and mouse primary peritoneal macrophages. The mechanisms responsible for these effects were attributed to the inhibitory role of fraxinellone in NF-κB signaling and NLRP3 inflammasome activation. Overall, our results support fraxinellone as a novel drug candidate in the treatment of colonic inflammation. - Highlights: • Fraxinellone, a lactone compound, alleviated DSS induced colitis. • The effects of fraxinellone were attributed to its inhibition on

Modulation of the nuclear factor-kappa B (NF-κB) signalling pathway by glutamine in peritoneal macrophages of a murine model of protein malnutrition.

Science.gov (United States)

da Silva Lima, Fabiana; Rogero, Marcelo Macedo; Ramos, Mayara Caldas; Borelli, Primavera; Fock, Ricardo Ambrósio

2013-06-01

Protein malnutrition affects resistance to infection by impairing the inflammatory response, modifying the function of effector cells, such as macrophages. Recent studies have revealed that glutamine-a non-essential amino acid, which could become conditionally essential in some situations like trauma, infection, post-surgery and sepsis-is able to modulate the synthesis of cytokines. The aim of this study was to evaluate the effect of glutamine on the expression of proteins involved in the nuclear factor-kappa B (NF-κB) signalling pathway of peritoneal macrophages from malnourished mice. Two-month-old male Balb/c mice were submitted to protein-energy malnutrition (n = 10) with a low-protein diet containing 2 % protein, whereas control mice (n = 10) were fed a 12 % protein-containing diet. The haemogram and analysis of plasma glutamine and corticosterone were evaluated. Peritoneal macrophages were pre-treated in vitro with glutamine (0, 0.6, 2 and 10 mmol/L) for 24 h and then stimulated with 1.25 μg LPS for 30 min, and the synthesis of TNF-α and IL-1α and the expression of proteins related to the NF-κB pathway were evaluated. Malnourished animals had anaemia, leucopoenia, lower plasma glutamine and increased corticosterone levels. TNF-α production of macrophages stimulated with LPS was significantly lower in cells from malnourished animals when cultivated in supraphysiological (2 and 10 mmol/L) concentrations of glutamine. Further, glutamine has a dose-dependent effect on the activation of macrophages, in both groups, when stimulated with LPS, inducing a decrease in TNF-α and IL-1α production and negatively modulating the NF-κB signalling pathway. These data lead us to infer that the protein malnutrition state interferes with the activation of macrophages and that higher glutamine concentrations, in vitro, have the capacity to act negatively in the NF-κB signalling pathway.

Fisetin Alleviates Lipopolysaccharide-Induced Acute Lung Injury via TLR4-Mediated NF-κB Signaling Pathway in Rats.

Science.gov (United States)

Feng, Guang; Jiang, Ze-Yu; Sun, Bo; Fu, Jie; Li, Tian-Zuo

2016-02-01

Acute lung injury (ALI), a common component of systemic inflammatory disease, is a life-threatening condition without many effective treatments. Fisetin, a natural flavonoid from fruits and vegetables, was reported to have wide pharmacological properties such as anti-inflammatory, antioxidant, and anticancer activities. The aim of this study was to detect the effects of fisetin on lipopolysaccharide (LPS)-induced acute lung injury and investigate the potential mechanism. Fisetin was injected (1, 2, and 4 mg/kg, i.v.) 30 min before LPS administration (5 mg/kg, i.v.). Our results showed that fisetin effectively reduced the inflammatory cytokine release and total protein in bronchoalveolar lavage fluids (BALF), decreased the lung wet/dry ratios, and obviously improved the pulmonary histology in LPS-induced ALI. Furthermore, fisetin inhibited LPS-induced increases of neutrophils and macrophage infiltration and attenuated MPO activity in lung tissues. Additionally, fisetin could significantly inhibit the Toll-like receptor 4 (TLR4) expression and the activation of NF-κB in lung tissues. Our data indicates that fisetin has a protective effect against LPS-induced ALI via suppression of TLR4-mediated NF-κB signaling pathways, and fisetin may be a promising candidate for LPS-induced ALI treatment.

Induction of activator protein (AP)-1 and nuclear factor-kappaB by CD28 stimulation involves both phosphatidylinositol 3-kinase and acidic sphingomyelinase signals.

Science.gov (United States)

Edmead, C E; Patel, Y I; Wilson, A; Boulougouris, G; Hall, N D; Ward, S G; Sansom, D M

1996-10-15

A major obstacle in understanding the signaling events that follow CD28 receptor ligation arises from the fact that CD28 acts as a costimulus to TCR engagement, making it difficult to assess the relative contribution of CD28 signals as distinct from those of the TCR. To overcome this problem, we have exploited the observation that activated human T cell blasts can be stimulated via the CD28 surface molecule in the absence of antigenic challenge; thus, we have been able to observe the response of normal T cells to CD28 activation in isolation. Using this system, we observed that CD28 stimulation by B7-transfected CHO cells induced a proliferative response in T cells that was not accompanied by measurable IL-2 production. However, subsequent analysis of transcription factor generation revealed that B7 stimulation induced both activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) complexes, but not NF-AT. In contrast, engagement of the TCR by class II MHC/superantigen, either with or without CD28 ligation, resulted in the induction of NF-AT, AP-1, and NF-kappaB as well as IL-2 production. Using selective inhibitors, we investigated the signaling pathways involved in the CD28-mediated induction of AP-1 and NF-kappaB. This revealed that NF-kappaB generation was sensitive to chloroquine, an inhibitor of acidic sphingomyelinase, but not to the phosphatidylinositol 3-kinase inhibitor, wortmannin. In contrast, AP-1 generation was inhibited by wortmannin and was also variably sensitive to chloroquine. These data suggest that in activated normal T cells, CD28-derived signals can stimulate proliferation at least in part via NF-kappaB and AP-1 generation, and that this response uses both acidic sphingomyelinase and phosphatidylinositol 3-kinase-linked pathways.

10−7 m 17β-oestradiol enhances odonto/osteogenic potency of human dental pulp stem cells by activation of the NF-κB pathway

Science.gov (United States)

Wang, Y; Zheng, Y; Wang, Z; Li, J; Wang, Z; Zhang, G; Yu, J

2013-01-01

Objectives Oestrogen has been proven to significantly enhance osteogenic potency, while oestrogen deficiency usually leads to impaired osteogenic differentiation of mesenchymal stem cells. However, little is known concerning direct effects of oestrogen on differentiation of human dental pulp stem cells (DPSCs). Materials and methods In this study, human DPSCs were isolated and treated with 10−7 m 17β-oestradiol (E2). Alkaline phosphatase (ALP) assay and alizarin red staining were performed. Results Alkaline phosphatase and alizarin red showed that E2 treatment significantly enhanced ALP activity and mineralization ability of DPSCs, but had no effect on cell proliferation. Real-time RT-PCR and western blot assay demonstrated that odonto/osteogenic markers (ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN and DSPP/DSP) were significantly upregulated in the cells after E2 treatment. Moreover, phosphorylation of cytoplasmic IκBα/P65 and expression of nuclear P65 were enhanced in a time-dependent manner following E2 treatment, suggesting activation of NF-κB signaling. Conversely, inhibition of the NF-κB pathway suppressed E2-mediated upregulation of odonto/osteogenic markers, indicating that the NF-κB pathway was pivotal for E2-mediated differentiation. Conclusion These findings provide evidence that 10−7 m 17β-oestradiol promoted odonto/osteogenic differentiation of human DPSCs via activation of the NF-κB signaling pathway. PMID:24152244

Molecular mechanisms of BMP-induced bone formation: Cross-talk between BMP and NF-κB signaling pathways in osteoblastogenesis

Directory of Open Access Journals (Sweden)

Eijiro Jimi

2010-02-01

Full Text Available Osteoblasts are bone-forming cells that differentiate from mesenchymal stem cells. Differentiation processes are coordinately and dynamically controlled in the mesenchymal cells by specific signal transduction pathways. Bone morphogenetic proteins (BMPs, members of the TGF-β superfamily, induce not only bone formation in vivo, but also osteoblast differentiation of mesenchymal cells in vitro. BMP signals are transduced from plasma membrane receptors to the nucleus through both Smad-dependent and -independent pathways, and are regulated by many extracellular and intercellular proteins that interact with BMPs or components of BMP signaling pathways. To understand the molecular mechanisms underlying the role of BMPs in osteoblast differentiation, it is important to elucidate the BMP signaling transduction pathways that are active during osteoblast differentiation. In this review, we summarize the BMP signaling pathways that are known to function in osteoblast development. We also describe our recent findings regarding the molecular mechanisms underlying the cross-talk between BMP/Smad and NF-κB pathways in osteoblast differentiation.

TLR4/MyD88/NF-κB signaling and PPAR-γ within the paraventricular nucleus are involved in the effects of telmisartan in hypertension

Energy Technology Data Exchange (ETDEWEB)

Li, Hong-Bao; Li, Xiang; Huo, Chan-Juan; Su, Qing; Guo, Jing [Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Health Science Center, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an 710061 (China); Yuan, Zu-Yi [Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi' an Jiaotong University, Xi' an 710061 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Shi, Xiao-Lian, E-mail: shxl@mail.xjtu.edu.cn [Department of Pharmacology, School of Basic Medical Sciences, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Liu, Jin-Jun, E-mail: jupet@163.com [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Health Science Center, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an 710061 (China)

2016-08-15

Previous findings from our laboratory and others indicate that the main therapeutic effect of angiotensin II type 1 receptor (AT1-R) antagonists is to decrease blood pressure and exert anti-inflammatory effects in the cardiovascular system. In this study, we determined whether AT1-R antagonist telmisartan within the hypothalamic paraventricular nucleus (PVN) attenuates hypertension and hypothalamic inflammation via both the TLR4/MyD88/NF-κB signaling pathway and peroxisome proliferator-activated receptor-γ (PPAR-γ) in the PVN in hypertensive rats. Spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats were treated for 4 weeks through bilateral PVN infusion with the AT1-R antagonist telmisartan (TEL, 10 μg/h), or losartan (LOS, 20 μg/h), or the PPAR-γ antagonist GW9662 (GW, 100 μg/h), or vehicle via osmotic minipump. Mean arterial pressure (MAP) was recorded by a tail-cuff occlusion method. PVN tissue and blood were collected for the measurement of AT1-R, PPAR-γ, pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6), inducible nitric oxide synthase (iNOS), TLR4, MyD88, nuclear factor-kappa B (NF-κB) activity and plasma norepinephrine (NE), respectively. Hypertensive rats exhibited significantly higher level of AT1-R and lower level of PPAR-γ in the PVN. PVN treatment with TEL attenuated MAP, improved cardiac hypertrophy, reduced TNF-α, IL-1β, IL-6, iNOS levels, and plasma NE in SHR but not in WKY rats. These results were associated with reduced TLR4, MyD88 and NF-κB levels and increased PPAR-γ level in the PVN of hypertensive rats. Our findings suggest that TLR4/MyD88/NF-κB signaling and PPAR-γ within the PVN are involved in the beneficial effects of telmisartan in hypertension. - Highlights: • PVN infusion of TEL in spontaneously hypertensive rats is reported. • PVN infusion of TEL attenuates hypertension and proinflammatory cytokines in PVN. • PVN blockade of AT1-R attenuates

Diarctigenin, a lignan constituent from Arctium lappa, down-regulated zymosan-induced transcription of inflammatory genes through suppression of DNA binding ability of nuclear factor-kappaB in macrophages.

Science.gov (United States)

Kim, Byung Hak; Hong, Seong Su; Kwon, Soon Woo; Lee, Hwa Young; Sung, Hyeran; Lee, In-Jeong; Hwang, Bang Yeon; Song, Sukgil; Lee, Chong-Kil; Chung, Daehyun; Ahn, Byeongwoo; Nam, Sang-Yoon; Han, Sang-Bae; Kim, Youngsoo

2008-11-01

Diarctigenin was previously isolated as an inhibitor of nitric oxide (NO) production in macrophages from the seeds of Arctium lappa used as an alternative medicine for the treatment of inflammatory disorders. However, little is known about the molecular basis of these effects. Here, we demonstrated that diarctigenin inhibited the production of NO, prostaglandin E(2), tumor necrosis factor-alpha, and interleukin (IL)-1beta and IL-6 with IC(50) values of 6 to 12 miciroM in zymosan- or lipopolysaccharide-(LPS) activated macrophages. Diarctigenin attenuated zymosan-induced mRNA synthesis of inducible NO synthase (iNOS) and also inhibited promoter activities of iNOS and cytokine genes in the cells. Because nuclear factor (NF)-kappaB plays a pivotal role in inflammatory gene transcription, we next investigated the effect of diarctigenin on NF-kappaB activation. Diarctigenin inhibited the transcriptional activity and DNA binding ability of NF-kappaB in zymosan-activated macrophages but did not affect the degradation and phosphorylation of inhibitory kappaB (IkappaB) proteins. Moreover, diarctigenin suppressed expression vector NF-kappaB p65-elicited NF-kappaB activation and also iNOS promoter activity, indicating that the compound could directly target an NF-kappa-activating signal cascade downstream of IkappaB degradation and inhibit NF-kappaB-regulated iNOS expression. Diarctigenin also inhibited the in vitro DNA binding ability of NF-kappaB but did not affect the nuclear import of NF-kappaB p65 in the cells. Taken together, diarctigenin down-regulated zymosan- or LPS-induced inflammatory gene transcription in macrophages, which was due to direct inhibition of the DNA binding ability of NF-kappaB. Finally, this study provides a pharmacological potential of diarctigenin in the NF-kappaB-associated inflammatory disorders.

Evidence of correlation between TGFBR2 gene expression mediated by NF-kB signaling pathways and Kawasaki disease in children.

Science.gov (United States)

Gao, Qinling; Yuan, Shuhua; Yuan, Dawei

2017-09-15

We explored the correlation between the TGFBR2 gene that is mediated by NF-kb signaling pathways and the pathogenesis of Kawasaki disease in children. In this study, 43 children with Kawasaki disease from April 2014 to January 2016 at our hospital were selected as the observation group, and 42 healthy children were selected as the control group. The mRNA expression levels of NF-kb gene and TGFBR2 gene in different groups were detected using fluorescence quantitative PCR. The protein expression levels of the NF-kb and TGFBR2 were detected using enzyme-linked immunosorbent assay (ELISA) in different groups. The expression levels of NF-kb and TGFBR2 in the observation group and the control group were detected using immunohistochemistry. Compared to the control group, the mRNA expression levels of NF-kb and TGFBR2 were 12.3 times and 27.5 times as high as those in the control group respectively and there were significant differences between the two groups (pkb and TGFBR2 in the control group (0.87±0.12, 1.25±0.18) ug/l and those in the observation group (3.27±0.17, 8.16±0.22) ug/l (pkB and TGFBR2 in children with Kawasaki disease were significantly higher than those in healthy subjects (pkB signaling pathways.

A Family of Salmonella Type III Secretion Effector Proteins Selectively Targets the NF-κB Signaling Pathway to Preserve Host Homeostasis.

Science.gov (United States)

Sun, Hui; Kamanova, Jana; Lara-Tejero, Maria; Galán, Jorge E

2016-03-01

Microbial infections usually lead to host innate immune responses and inflammation. These responses most often limit pathogen replication although they can also result in host-tissue damage. The enteropathogenic bacteria Salmonella Typhimurium utilizes a type III secretion system to induce intestinal inflammation by delivering specific effector proteins that stimulate signal transduction pathways resulting in the production of pro-inflammatory cytokines. We show here that a family of related Salmonella Typhimurium effector proteins PipA, GogA and GtgA redundantly target components of the NF-κB signaling pathway to inhibit transcriptional responses leading to inflammation. We show that these effector proteins are proteases that cleave both the RelA (p65) and RelB transcription factors but do not target p100 (NF-κB2) or p105 (NF-κB1). A Salmonella Typhimurium strain lacking these effectors showed increased ability to stimulate NF-κB and increased virulence in an animal model of infection. These results indicate that bacterial pathogens can evolve determinants to preserve host homeostasis and that those determinants can reduce the pathogen's virulence.

Fibroblast growth factor 21 attenuates hepatic fibrogenesis through TGF-β/smad2/3 and NF-κB signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Xu, Pengfei; Zhang, Yingjie; Liu, Yunye; Yuan, Qingyan; Song, Liying; Liu, Mingyao; Liu, Zhihang; Yang, Yongbi; Li, Junyan; Li, Deshan, E-mail: deshanli@163.com; Ren, Guiping, E-mail: renguiping@126.com

2016-01-01

Fibroblast growth factor 21 (FGF-21) is a secreted protein, which has anti-diabetic and lipocaic effects, but its ability to protect against hepatic fibrosis has not been studied. In this study, we investigated the ability of FGF-21 to attenuate dimethylnitrosamine (DMN)-induced hepatic fibrogenesis in mice and the mechanism of its action. Hepatic fibrosis was induced by injection of DMN, FGF-21 was administered to the mice once daily in association with DMN injection till the end of the experiment. Histopathological examination, tissue 4-hydroxyproline content and expressions of smooth muscle α-actin (α-SMA) and collagen I were measured to assess hepatic fibrosis. Ethanol/PDGF-BB-activated hepatic stellate cells (HSCs) were used to understand the mechanisms of FGF-21 inhibited hepatic fibrogenesis. Results showed that FGF-21 treatment attenuated hepatic fibrogenesis and was associated with a significant decrease in intrahepatic fibrogenesis, 4-hydroxyproline accumulation, α-SMA expression and collagen I deposition. FGF-21 treatment inhibited the activation of HSCs via down-regulating the expression of TGF-β, NF-κB nuclear translocation, phosphorylation levels of smad2/3 and IκBα. Besides, FGF-21 treatment caused activated HSC apoptosis with increasing expression of Caspase-3, and decreased the ratio of Bcl-2 to Bax. In conclusion, FGF-21 attenuates hepatic fibrogenesis and inhibits the activation of HSC warranting the use of FGF-21 as a potential therapeutic agent in the treatment of hepatic fibrosis. - Highlights: • Fibroblast growth factor 21 attenuates hepatic fibrogenesis. • Fibroblast growth factor 21 attenuates hepatic fibrogenesis via TGF-β/smad2/3 signaling pathways. • Fibroblast growth factor 21 attenuates hepatic fibrogenesis via NF-κB signaling pathways.

Altholactone Inhibits NF-κB and STAT3 Activation and Induces Reactive Oxygen Species-Mediated Apoptosis in Prostate Cancer DU145 Cells

Directory of Open Access Journals (Sweden)

Chunwa Jiang

2017-02-01

Full Text Available Altholactone, a natural compound isolated from Goniothalamus spp., has demonstrated anti-inflammatory and anticancer activities, but its molecular mechanisms are still not fully defined. Nuclear factor kappa B (NF-κB and signal transducer and activator of transcription 3 (STAT3 play pivotal roles in the cell survival of many human tumors. The objective of this study was to elucidate the mechanism of action of altholactone against prostate cancer DU145 cells and to evaluate whether its effects are mediated by inhibition of NF-κB and STAT3 activity. Altholactone inhibited proliferation of DU145 cells and induced cell cycle arrest in S phase and triggered apoptosis. Reporter assays revealed that altholactone repressed p65- and TNF-α-enhanced NF-κB transcriptional activity and also inhibited both constitutive and IL-6-induced transcriptional activity of STAT3. Consistent with this, altholactone down-regulated phosphorylation of STAT3 and moreover, decreased constitutively active mutant of STAT3 (STAT3C-induced transcriptional activity. Altholactone treatment also results in down-regulation of STAT3 target genes such as survivin, and Bcl-2 followed by up regulation of pro-apoptotic Bax protein. However, pre-treatment with the antioxidant N-acetylcysteine (NAC significantly inhibited the activation of Bax and prevented down-regulation of STAT3 target genes. Collectively, our findings suggest that altholactone induces DU145 cells death through inhibition of NF-κB and STAT3 activity.

Oligonol Ameliorates CCl4-Induced Liver Injury in Rats via the NF-Kappa B and MAPK Signaling Pathways

Directory of Open Access Journals (Sweden)

Jeonghyeon Bak

2016-01-01

Full Text Available Oxidative stress is thought to be a key risk factor in the development of hepatic diseases. Blocking or retarding the reactions of oxidation and the inflammatory process by antioxidants could be a promising therapeutic intervention for prevention or treatment of liver injuries. Oligonol is a low molecular weight polyphenol containing catechin-type monomers and oligomers derived from lychee fruit. In this study, we investigated the anti-inflammatory effect of oligonol on carbon tetrachloride- (CCl4- induced acute hepatic injury in rats. Oral administration of oligonol (10 or 50 mg/kg reduced CCl4-induced abnormalities in liver histology and serum AST and serum ALT levels. Oligonol treatment attenuated the CCl4-induced production of inflammatory mediators, including TNF-α, IL-1β, cyclooxygenase-2 (COX-2, and inducible nitric oxide synthase (iNOS mRNA levels. Western blot analysis showed that oligonol suppressed proinflammatory nuclear factor-kappa B (NF-κB p65 activation, phosphorylation of extracellular signal-regulated kinase (ERK, c-Jun NH2-terminal kinase (JNK, and p38 mitogen-activated protein kinases (MAPKs as well as Akt. Oligonol exhibited strong antioxidative activity in vitro and in vivo, and hepatoprotective activity against t-butyl hydroperoxide-induced HepG2 cells. Taken together, oligonol showed antioxidative and anti-inflammatory effects in CCl4-intoxicated rats by inhibiting oxidative stress and NF-κB activation via blockade of the activation of upstream kinases including MAPKs and Akt.

A noncanonical Flt3ITD/NF-κB signaling pathway represses DAPK1 in acute myeloid leukemia.

Science.gov (United States)

Shanmugam, Rajasubramaniam; Gade, Padmaja; Wilson-Weekes, Annique; Sayar, Hamid; Suvannasankha, Attaya; Goswami, Chirayu; Li, Lang; Gupta, Sushil; Cardoso, Angelo A; Baghdadi, Tareq Al; Sargent, Katie J; Cripe, Larry D; Kalvakolanu, Dhananjaya V; Boswell, H Scott

2012-01-15

Death-associated protein kinase 1 (DAPK1), a tumor suppressor, is a rate-limiting effector in an endoplasmic reticulum (ER) stress-dependent apoptotic pathway. Its expression is epigenetically suppressed in several tumors. A mechanistic basis for epigenetic/transcriptional repression of DAPK1 was investigated in certain forms of acute myeloid leukemia (AML) with poor prognosis, which lacked ER stress-induced apoptosis. Heterogeneous primary AMLs were screened to identify a subgroup with Flt3ITD in which repression of DAPK1, among NF-κB-and c-Jun-responsive genes, was studied. RNA interference knockdown studies were carried out in an Flt3ITD(+) cell line, MV-4-11, to establish genetic epistasis in the pathway Flt3ITD-TAK1-DAPK1 repression, and chromatin immunoprecipitations were carried out to identify proximate effector proteins, including TAK1-activated p52NF-κB, at the DAPK1 locus. AMLs characterized by normal karyotype with Flt3ITD were found to have 10- to 100-fold lower DAPK1 transcripts normalized to the expression of c-Jun, a transcriptional activator of DAPK1, as compared with a heterogeneous cytogenetic category. In addition, Meis1, a c-Jun-responsive adverse AML prognostic gene signature was measured as control. These Flt3ITD(+) AMLs overexpress relB, a transcriptional repressor, which forms active heterodimers with p52NF-κB. Chromatin immunoprecipitation assays identified p52NF-κB binding to the DAPK1 promoter together with histone deacetylase 2 (HDAC2) and HDAC6 in the Flt3ITD(+) human AML cell line MV-4-11. Knockdown of p52NF-κB or its upstream regulator, NF-κB-inducing kinase (NIK), de-repressed DAPK1. DAPK1-repressed primary Flt3ITD(+) AMLs had selective nuclear activation of p52NF-κB. Flt3ITD promotes a noncanonical pathway via TAK1 and p52NF-κB to suppress DAPK1 in association with HDACs, which explains DAPK1 repression in Flt3ITD(+) AML. ©2011 AACR.

Noisy transcription factor NF-¿B oscillations stabilize and sensitize cytokine signaling in space

DEFF Research Database (Denmark)

Gangstad, S.W.; Feldager, C.W.; Juul, Jeppe Søgaard

2013-01-01

NF-¿B is a major transcription factor mediating inflammatory response. In response to a pro-inflammatory stimulus, it exhibits a characteristic response - a pulse followed by noisy oscillations in concentrations of considerably smaller amplitude. NF-¿B is an important mediator of cellular...... amplitude has not been addressed. We use a cellular automaton model to address these issues in the context of spatially distributed communicating cells. We find that noisy secondary oscillations stabilize concentric wave patterns, thus improving signal quality. Furthermore, both lower secondary amplitude...... as well as noise in the oscillation period might be working against chronic inflammation, the state of self-sustained and stimulus-independent excitations. Our findings suggest that the characteristic irregular secondary oscillations of lower amplitude are not accidental. On the contrary, they might have...

FTO Inhibits Insulin Secretion and Promotes NF-κB Activation through Positively Regulating ROS Production in Pancreatic β cells.

Directory of Open Access Journals (Sweden)

Hong-Qi Fan

Full Text Available FTO (Fat mass and obesity-associated is associated with increased risk of obesity and type 2 diabetes incurrence. Pancreas islet β cells dysfunction and insulin resistance are major causes of type 2 diabetes. However, whether FTO plays an important functional role in pancreatic β cells as well as the related molecular mechanism is still unclear. In the present study, the tissue expression profile of FTO was firstly determined using quantitative PCR and western blot. FTO is widely expressed in various tissues and presented with relative high expression in pancreas tissue, especially in endocrine pancreas. FTO overexpression in MIN6 cells achieved by lentivirus delivery significantly inhibits insulin secretion in the presence of glucose stimulus as well as KCl. FTO silence has no effect on insulin secretion of MIN6 cells. However, FTO overexpression doesn't affect the transcription of insulin gene. Furthermore, reactive oxygen species (ROS production and NF-κB activation are significantly promoted by FTO overexpression. Inhibition of intracellular ROS production by N-acetyl-L-cysteine (NAC can alleviate NF-κB activation and restore the insulin secretion mediated by FTO overexpression. A whole transcript-microarray is employed to analyze the differential gene expression mediated by FTO overexpression. The genes which are modulated by FTO are involved in many important biological pathways such as G-protein coupled receptor signaling and NF-κB signaling. Therefore, our study indicates that FTO may contribute to pancreas islet β cells dysfunction and the inhibition of FTO activity is a potential target for the treatment of diabetes.

Heme activates TLR4-mediated inflammatory injury via MyD88/TRIF signaling pathway in intracerebral hemorrhage

Directory of Open Access Journals (Sweden)

Lin Sen

2012-03-01

Full Text Available Abstract Background Inflammatory injury plays a critical role in intracerebral hemorrhage (ICH-induced neurological deficits; however, the signaling pathways are not apparent by which the upstream cellular events trigger innate immune and inflammatory responses that contribute to neurological impairments. Toll-like receptor 4 (TLR4 plays a role in inflammatory damage caused by brain disorders. Methods In this study, we investigate the role of TLR4 signaling in ICH-induced inflammation. In the ICH model, a significant upregulation of TLR4 expression in reactive microglia has been demonstrated using real-time RT-PCR. Activation of microglia was detected by immunohistochemistry, cytokines were measured by ELISA, MyD88, TRIF and NF-κB were measured by Western blot and EMSA, animal behavior was evaluated by animal behavioristics. Results Compared to WT mice, TLR4−/− mice had restrained ICH-induced brain damage showing in reduced cerebral edema and lower neurological deficit scores. Quantification of cytokines including IL-6, TNF-α and IL-1β and assessment of macrophage infiltration in perihematoma tissues from TLR4−/−, MyD88−/− and TRIF−/− mice showed attenuated inflammatory damage after ICH. TLR4−/− mice also exhibited reduced MyD88 and TRIF expression which was accompanied by decreased NF-κB activity. This suggests that after ICH both MyD88 and TRIF pathways might be involved in TLR4-mediated inflammatory injury possibly via NF-κB activation. Exogenous hemin administration significantly increased TLR4 expression and microglial activation in cultures and also exacerbated brain injury in WT mice but not in TLR4−/− mice. Anti-TLR4 antibody administration suppressed hemin-induced microglial activation in cultures and in the mice model of ICH. Conclusions Our findings suggest that heme potentiates microglial activation via TLR4, in turn inducing NF-κB activation via the MyD88/TRIF signaling pathway, and ultimately

Human T-cell leukemia virus type 1 (HTLV-1 tax requires CADM1/TSLC1 for inactivation of the NF-κB inhibitor A20 and constitutive NF-κB signaling.

Directory of Open Access Journals (Sweden)

Rajeshree Pujari

2015-03-01

Full Text Available Persistent activation of NF-κB by the Human T-cell leukemia virus type 1 (HTLV-1 oncoprotein, Tax, is vital for the development and pathogenesis of adult T-cell leukemia (ATL and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. K63-linked polyubiquitinated Tax activates the IKK complex in the plasma membrane-associated lipid raft microdomain. Tax also interacts with TAX1BP1 to inactivate the NF-κB negative regulatory ubiquitin-editing A20 enzyme complex. However, the molecular mechanisms of Tax-mediated IKK activation and A20 protein complex inactivation are poorly understood. Here, we demonstrated that membrane associated CADM1 (Cell adhesion molecule1 recruits Ubc13 to Tax, causing K63-linked polyubiquitination of Tax, and IKK complex activation in the membrane lipid raft. The c-terminal cytoplasmic tail containing PDZ binding motif of CADM1 is critical for Tax to maintain persistent NF-κB activation. Finally, Tax failed to inactivate the NF-κB negative regulator ubiquitin-editing enzyme A20 complex, and activate the IKK complex in the lipid raft in absence of CADM1. Our results thus indicate that CADM1 functions as a critical scaffold molecule for Tax and Ubc13 to form a cellular complex with NEMO, TAX1BP1 and NRP, to activate the IKK complex in the plasma membrane-associated lipid rafts, to inactivate NF-κB negative regulators, and maintain persistent NF-κB activation in HTLV-1 infected cells.

Adrenergic regulation during acute hepatic infection with Entamoeba histolytica in the hamster: involvement of oxidative stress, Nrf2 and NF-KappaB

Directory of Open Access Journals (Sweden)

Aldaba-Muruato Liseth Rubi

2017-01-01

Full Text Available Oxidative stress and transcriptional pathways of nuclear factor erythroid 2-related factor 2 (Nrf2 and nuclear factor kappa-B (NF-κB are critically involved in the etiopathology of amebic liver abscess (ALA. In this work, we studied the relationship between the adrenergic nervous system and ALA in the hamster. ALA was visible at 12 h of infection. While 6-hydroxidopamine (6-OHDA decreased infection, propranolol (β-adrenergic blocker treatment was associated with less extensive liver damage, and phentolamine treatment (α-adrenergic blocker significantly reduced ALA compared to 6-OHDA and propranolol. Serum enzymatic activities of alanine aminotransferase (ALT and γ-glutamyl transpeptidase (γ-GTP were increased at 12 h post-infection. Chemical denervation and α and β-adrenergic blockers decreased ALT to normal levels, while 6-OHDA and propranolol showed a trend to decrease γ-GTP but phentolamine significantly reduced γ-GTP. Amebic infection increased oxidized glutathione (GSSG and decreased both reduced glutathione (GSH and the GSH/GSSG ratio. Propranolol and 6-OHDA showed a tendency to decrease GSSG. However, GSH, GSSG and GSH/GSSG returned to normal levels with phentolamine. Furthermore, amebic infection increased pNF-κB and interleukin-1β (IL-1β, and showed a tendency to decrease hemoxigenase-1 (HO-1, but not Nrf2. Chemical denervation showed a trend to decrease pNF-κB and IL-1β, and neither Nrf2 nor HO-1 increased significantly. In addition, NF-κB and IL-1β were attenuated by propranolol and phentolamine treatments, although phentolamine showed significant overexpression of Nrf2 and HO-1. This suggests that the adrenergic system may be involved in oxidative stress and in modulation of the Nrf2 and NF-κB pathways during ALA development.

Persistent activation of NF-kappaB related to IkappaB's degradation profiles during early chemical hepatocarcinogenesis

Directory of Open Access Journals (Sweden)

García-Román Rebeca

2007-04-01

Full Text Available Abstract Background To define the NF-kappaB activation in early stages of hepatocarcinogenesis and its IkappaB's degradation profiles in comparison to sole liver regeneration. Methods Western-blot and EMSA analyses were performed for the NF-kappaB activation. The transcriptional activity of NF-kappaB was determined by RT-PCR of the IkappaB-α mRNA. The IkappaB's degradation proteins were determined by Western-blot assay. Results We demonstrated the persistent activation of NF-kappaB during early stages of hepatocarcinogenesis, which reached maximal level 30 min after partial hepatectomy. The DNA binding and transcriptional activity of NF-kappaB, were sustained during early steps of hepatocarcinogenesis in comparison to only partial hepatectomy, which displayed a transitory NF-kappaB activation. In early stages of hepatocarconogenesis, the IkappaB-α degradation turned out to be acute and transitory, but the low levels of IkappaB-β persisted even 15 days after partial hepatectomy. Interestingly, IkappaB-β degradation is not induced after sole partial hepatectomy. Conclusion We propose that during liver regeneration, the transitory stimulation of the transcription factor response, assures blockade of NF-kappaB until recovery of the total mass of the liver and the persistent NF-kappaB activation in early hepatocarcinogenesis may be due to IkappaB-β and IkappaB-α degradation, mainly IkappaB-β degradation, which contributes to gene transcription related to proliferation required for neoplasic progression.

The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

2016-01-15

Highlights: • α-irradiated Beas-2B cells induced bystander effects in macrophage U937 cells. • The neighboring macrophages enhanced the damage of α-irradiated Beas-2B cells. • MAPK and NF-κB pathways were activated in U937 cells after cell co-culture. • NF-κB and MAPK pathways participated in the bilateral bystander responses. - Abstract: Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage.

The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways

International Nuclear Information System (INIS)

Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin

2016-01-01

Highlights: • α-irradiated Beas-2B cells induced bystander effects in macrophage U937 cells. • The neighboring macrophages enhanced the damage of α-irradiated Beas-2B cells. • MAPK and NF-κB pathways were activated in U937 cells after cell co-culture. • NF-κB and MAPK pathways participated in the bilateral bystander responses. - Abstract: Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage.

Fisetin Protects against Intracerebral Hemorrhage-Induced Neuroinflammation in Aged Mice.

Science.gov (United States)

Chen, Cheng; Yao, Li; Cui, Jing; Liu, Bao

2018-01-01

Fisetin is commonly used as an anti-inflammatory and neuroprotective drug. In this study, we aimed to investigate the efficacy of fisetin in alleviating intracerebral hemorrhage (ICH)-induced brain injury. Mouse ICH models were constructed using the collagenase-induction method. ICH mice received fisetin treatment at the dose of 10-90 mg/kg, followed by the evaluation of neurological deficit through neurologic severity scores (mNSS), brain water content and terminal deoxynucleotidyl transferase dUTP nick end labeling analysis of cell apoptosis. Cytokine levels were also assessed with enzyme-linked immunosorbent assay. The activation of astrocytes and microglia was evaluated through S100 staining and Western blot analysis of ionized calcium-binding adaptor molecule 1 respectively. Nuclear factor kappa-B (NF-κB) signaling was also evaluated by Western blot. ICH mice demonstrated dramatic increase in mNSS, brain edema and cell apoptosis, indicating severe brain deficit. Fisetin treatment lowered these parameters, suggesting the alleviation of brain injury. Levels of proinflammatory cytokines were reduced, accompanied by a prominent decrease in activated astrocytes and microglia. NF-κB signaling was also attenuated by fisetin treatment. Fisetin effectively alleviates ICH by downregulating proinflammatory cytokines and attenuating NF-κB signaling. These data suggest fisetin as a valuable natural flavonol for clinical management of ICH-induced brain injury. © 2018 S. Karger AG, Basel.

Nobiletin Inhibits CD36-Dependent Tumor Angiogenesis, Migration, Invasion, and Sphere Formation Through the Cd36/Stat3/Nf-Κb Signaling Axis

Directory of Open Access Journals (Sweden)

Nipin Sp

2018-06-01

Full Text Available Targeted cancer therapy with natural compounds is more effective than nontargeted therapy. Nobiletin is a flavonoid derived from citrus peel that has anticancer activity. Cluster of differentiation 36 (CD36 is a member of the class B scavenger receptor family that is involved in importing fatty acids into cells. CD36 plays a role in tumor angiogenesis by binding to its ligand, thrombospondin-1 (TSP-1, and then interacting with transforming growth factor beta 1 (TGFβ1. CD36 is implicated in tumor metastasis through its roles in fatty acid metabolism. This study investigated the molecular mechanisms underlying nobiletin’s anticancer activity by characterizing its interactions with CD36 as the target molecule. We hypothesize that the anti-angiogenic activity of nobiletin involving its regulation of CD36 via signal transducer and activator of transcription 3 (STAT3 rather than through TSP-1. Gene analysis identified a Gamma interferon activation site (GAS element in the CD36 gene promoter that acts as a STAT3 binding site, an interaction that was confirmed by ChIP assay. STAT3 interacts with nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB, suggesting that nobiletin also acts through the CD36/ (STAT3/NF-κB signaling axis. Nobiletin inhibited CD36-dependent breast cancer cell migration and invasion as well as CD36-mediated tumor sphere formation. Taken together, these results suggest that nobiletin inhibits cancer stem cells in multiple ways.

14-3-3γ Regulates Lipopolysaccharide-Induced Inflammatory Responses and Lactation in Dairy Cow Mammary Epithelial Cells by Inhibiting NF-κB and MAPKs and Up-Regulating mTOR Signaling

Directory of Open Access Journals (Sweden)

Lixin Liu

2015-07-01

Full Text Available As a protective factor for lipopolysaccharide (LPS-induced injury, 14-3-3γ has been the subject of recent research. Nevertheless, whether 14-3-3γ can regulate lactation in dairy cow mammary epithelial cells (DCMECs induced by LPS remains unknown. Here, the anti-inflammatory effect and lactation regulating ability of 14-3-3γ in LPS-induced DCMECs are investigated for the first time, and the molecular mechanisms responsible for their effects are explored. The results of qRT-PCR showed that 14-3-3γ overexpression significantly inhibited the mRNA expression of tumor necrosis factor-α (TNF-α, interleukin-6 (IL-6, interleukin-1β (IL-1β and inducible nitric oxide synthase (iNOS. Enzyme-linked immunosorbent assay (ELISA analysis revealed that 14-3-3γ overexpression also suppressed the production of TNF-α and IL-6 in cell culture supernatants. Meanwhile, CASY-TT Analyser System showed that 14-3-3γ overexpression clearly increased the viability and proliferation of cells. The results of kit methods and western blot analysis showed that 14-3-3γ overexpression promoted the secretion of triglycerides and lactose and the synthesis of β-casein. Furthermore, the expression of genes relevant to nuclear factor-κB (NF-κB and mitogen-activated protein kinase (MAPKs and lactation-associated proteins were assessed by western blot, and the results suggested that 14-3-3γ overexpression inactivated the NF-κB and MAPK signaling pathways by down-regulating extracellular signal regulated protein kinase (ERK, p38 mitogen-activated protein kinase (p38MAPK and inhibitor of NF-κB (IκB phosphorylation levels, as well as by inhibiting NF-κB translocation. Meanwhile, 14-3-3γ overexpression enhanced the expression levels of β-casein, mammalian target of rapamycin (mTOR, ribosomal protein S6 kinase 1 (S6K1, serine/threonine protein kinase Akt 1 (AKT1, sterol regulatory element binding protein 1 (SREBP1 and peroxisome proliferator-activated receptor gamma

Effusanin E suppresses nasopharyngeal carcinoma cell growth by inhibiting NF-κB and COX-2 signaling.

Directory of Open Access Journals (Sweden)

Mingzhu Zhuang

Full Text Available Rabdosia serra is well known for its antibacterial, anti-inflammatory and antitumor activities, but no information has been available for the active compounds derived from this plant in inhibiting human nasopharyngeal carcinoma (NPC cell growth. In this study, we isolated and purified a natural diterpenoid from Rabdosia serra and identified its chemical structure as effusanin E and elucidated its underlying mechanism of action in inhibiting NPC cell growth. Effusanin E significantly inhibited cell proliferation and induced apoptosis in NPC cells. Effusanin E also induced the cleavage of PARP, caspase-3 and -9 proteins and inhibited the nuclear translocation of p65 NF-κB proteins. Moreover, effusanin E abrogated the binding of NF-κB to the COX-2 promoter, thereby inhibiting the expression and promoter activity of COX-2. Pretreatment with a COX-2 or NF-κB-selective inhibitor (celecoxib or ammonium pyrrolidinedithiocarbamate had an additive effect on the effusanin E-mediated inhibition of proliferation, while pretreatment with an activator of NF-κB/COX-2 (lipopolysaccharides abrogated the effusanin E-mediated inhibition of proliferation. Effusanin E also significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity, furthermore, the expression of p50 NF-κB and COX-2 were down-regulated in the tumors of nude mice. These data suggest that effusanin E suppresses p50/p65 proteins to down-regulate COX-2 expression, thereby inhibiting NPC cell growth. Our findings provide new insights into exploring effusanin E as a potential therapeutic compound for the treatment of human nasopharyngeal carcinoma.

Anti-cancer effect of bee venom in prostate cancer cells through activation of caspase pathway via inactivation of NF-κB.

Science.gov (United States)

Park, Mi Hee; Choi, Myoung Suk; Kwak, Dong Hoon; Oh, Ki-Wan; Yoon, Do Young; Han, Sang Bae; Song, Ho Sueb; Song, Min Jong; Hong, Jin Tae

2011-06-01

Bee venom has been used as a traditional medicine to treat arthritis, rheumatism, back pain, cancerous tumors, and skin diseases. However, the effects of bee venom on the prostate cancer and their action mechanisms have not been reported yet. To determine the effect of bee venom and its major component, melittin on the prostate cancer cells, apoptosis is analyzed by tunnel assay and apoptotic gene expression. For xenograft studies, bee venom was administrated intraperitoneally twice per week for 4 weeks, and the tumor growth was measured and the tumor were analyzed by immunohistochemistry. To investigate whether bee venom and melittin can inactivate nuclear factor kappa B (NF-κB), we assessed NF-κB activity in vitro and in vivo. Bee venom (1-10 µg/ml) and melittin (0.5-2.5 µg/ml) inhibited cancer cell growth through induction of apoptotic cell death in LNCaP, DU145, and PC-3 human prostate cancer cells. These effects were mediated by the suppression of constitutively activated NF-κB. Bee venom and melittin decreased anti-apoptotic proteins but induced pro-apoptotic proteins. However, pan caspase inhibitor abolished bee venom and melittin-induced apoptotic cell death and NF-κB inactivation. Bee venom (3-6 mg/kg) administration to nude mice implanted with PC-3 cells resulted in inhibition of tumor growth and activity of NF-κB accompanied with apoptotic cell death. Therefore, these results indicated that bee venom and melittin could inhibit prostate cancer in in vitro and in vivo, and these effects may be related to NF-κB/caspase signal mediated induction of apoptotic cell death. Copyright © 2010 Wiley-Liss, Inc.

Fucofuroeckol-A from Eisenia bicyclis Inhibits Inflammation in Lipopolysaccharide-Induced Mouse Macrophages via Downregulation of the MAPK/NF-κB Signaling Pathway

Directory of Open Access Journals (Sweden)

Sang-Hoon Lee

2016-01-01

Full Text Available Fucofuroeckol-A (FF isolated from an edible perennial brown seaweed Eisenia bicyclis was shown to be potent anti-inflammatory agents. FF suppressed the production of nitric oxide (NO and prostaglandin E2 (PGE2 and the expression of inducible nitric oxide synthase and cyclooxygenase-2 dose dependently in lipopolysaccharide- (LPS- induced RAW 264.7 mouse macrophages. An enzyme-linked immunosorbent assay and cytometric bead array assay demonstrated that FF significantly reduced the production of proinflammatory cytokines, such as interleukin-6 and tumor necrosis factor-α, and that of the monocyte chemoattractant protein-1. Moreover, FF reduced the activation of nuclear factor κB (NF-κB and mitogen-activated protein kinases (MAPKs. These results strongly suggest that the inhibitory effects of fucofuroeckol-A from E. bicyclis on LPS-induced NO and PGE2 production might be due to the suppression of the NF-κB and MAPK signaling pathway.

NF-κB is involved in the LPS-mediated proliferation and apoptosis of MAC-T epithelial cells as part of the subacute ruminal acidosis response in cows.

Science.gov (United States)

Fan, Wen-Jie; Li, He-Ping; Zhu, He-Shui; Sui, Shi-Ping; Chen, Pei-Ge; Deng, Yue; Sui, Tong-Ming; Wang, Yue-Ying

2016-11-01

To determine the effect of NF-κB on cell proliferation and apoptosis, we investigate the expression of inflammation and apoptosis-related factors in the bovine mammary epithelial cell line, MAC-T. MAC-T cells were cultured in vitro and MTT and LDH assays used to determine the effects of lipopolysaccharide (LPS) on proliferation and cytotoxicity respectively. RT-PCR and western blotting were used to evaluate the effect of LPS and NF-κB inhibition [pyrrolidine dithiocarbamate (PDTC) treatment] on the expression of inflammation and apoptosis-related factors. LPS significantly inhibited MAC-T cell proliferation in a dose- and time-dependent manner. Furthermore, LPS promoted apoptosis while the NF-кB inhibitor PDTC attenuated this effect. After LPS treatment, the NF-кB signaling pathway was activated, and the expression of inflammation and apoptosis-related factors increased. When PDTC blocked NF-кB signaling, the expression of inflammation and apoptosis-related factors were decreased in MAC-T cells. LPS activates the TLR4/NF-κB signaling pathway, inhibits proliferation and promotes apoptosis in MAC-T cells. NF-кB inhibition attenuates MAC-T cell apoptosis and TLR4/NF-κB signaling pathway. NF-кB inhibitor alleviating MAC-T cell apoptosis is presumably modulated by NF-кB.

Anti-proliferative effect of RCE-4 from Reineckia carnea on human cervical cancer HeLa cells by inhibiting the PI3K/Akt/mTOR signaling pathway and NF-κB activation.

Science.gov (United States)

Bai, Caihong; Yang, Xiaojiao; Zou, Kun; He, Haibo; Wang, Junzhi; Qin, Huilin; Yu, Xiaoqin; Liu, Chengxiong; Zheng, Juyan; Cheng, Fan; Chen, Jianfeng

2016-06-01

Cervical cancer is the second leading cause of cancer deaths in women worldwide. In recent years, the studies find that inflammation is a critical component of tumor progression, and the ideal therapeutic methods should be aimed at the inflammation reaction triggers. (1β,3β,5β,25S)-spirostan-1,3-diol1-[α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranoside] (RCE-4) was the main active composition of Reineckia carnea (Andr.) Kunth. It significantly induced apoptosis in cervical cancer Caski cells through the mitochondrial pathway in our previous studies; however, its underlying mechanism remains poorly understood. This study aimed to further evaluate the effect of RCE-4 on human cervical cancer HeLa cells. Based on this observation, we investigated the anti-cervical cancer effect of RCE-4 by modulating phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway, nuclear factor-kappa B (NF-κB) activation, and inflammation-related key factors in HeLa cells. The results indicated that the HeLa cell was the most sensitive with an IC50 of 7.01 μM; RCE-4 significantly promoted the release of cellular lactate dehydrogenase (LDH); increased DNA fragmentation and apoptosis; reduced PI3K, Akt, mTOR, and NF-κBp65 phosphorylation levels; increased the Bax and cleaved poly (ADP-ribose) polymerase (PARP) protein levels; suppressed Bcl-2 protein expression; elevated the Bax/Bcl-2 expression ratio; and decreased the interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) mRNA expressions in HeLa cells in a concentration-dependent manner. These findings suggest that RCE-4 exerted beneficially anti-cervical cancer effect on HeLa cells, mainly inhibiting PI3K/Akt/mTOR signaling pathway phosphorylation and NF-κB activation, promoting HeLa cell apoptosis. Graphical abstract Anti-tumor effect of RCE-4 on HeLa cells.