NFkB pathway

Neuronal dysfunction initiates several intracellular signaling cascades to release different proinflammatory cytokines and chemokines, as well as various reactive oxygen species. In addition to neurons, microglia, and astrocytes are also affected by this signaling cascade. This release can either be helpful, neutral or detrimental for cell survival. Toll-like receptors (TLRs) activate and signal their downstream pathway to activate NF-κB and pro-IL-1β, both of which are responsible for neuroinflammation and linked to the pathogenesis of different age-related neurological conditions. However, herein, recent aspects of polyphenols in the treatment of neurodegenerative diseases are assessed, with a focus on TLR regulation by polyphenols. Different polyphenol classes, including flavonoids, phenolic acids, phenolic alcohols, stilbenes, and lignans can potentially target TLR signaling in a distinct pathway. Further, some polyphenols can suppress overexpression of inflammatory mediators through TLR4/NF-κB/STAT signaling intervention, while others can reduce neuronal apoptosis via modulating the TLR4/MyD88/NF-κB-pathway in microglia/macrophages. Indeed, neurodegeneration etiology is complex and yet to be completely understood, it may be that targeting TLRs could reveal a number of molecular and pharmacological aspects related to neurodegenerative diseases. Thus, activating TLR signaling modulation via natural resources could provide new therapeutic potentiality in the treatment of neurodegeneration.

The IκB kinase (IKK) complex acts as the gatekeeper of canonical NF-κB signaling, thereby regulating immunity, inflammation and cancer. It consists of the catalytic subunits IKKα and IKKβ and the regulatory subunit NEMO/IKKγ. Here, we show that the ubiquitin binding domain (UBAN) in NEMO is essential for IKK/NF-κB activation in response to TNFα, but not IL-1β stimulation. By screening a natural compound library we identified an anthraquinone derivative that acts as an inhibitor of NEMO-ubiquitin binding (iNUB). Using biochemical and NMR experiments we demonstrate that iNUB binds to NEMO UBAN and competes for interaction with methionine-1-linked linear ubiquitin chains. iNUB inhibited NF-κB activation upon UBAN-dependent TNFα and TCR/CD28, but not UBAN-independent IL-1β stimulation. Moreover, iNUB was selectively killing lymphoma cells that are addicted to chronic B-cell receptor triggered IKK/NF-κB activation. Thus, iNUB disrupts the NEMO-ubiquitin protein-protein interaction interface and thereby inhibits physiological and pathological NF-κB signaling. NF-κ B signaling plays a crucial role in inflammation, immune responses, survival and cell proliferation 1. The canonical NF-κ B signaling can be activated through various pathways including TNF receptor (TNFR), IL-1 receptor (IL-1R) or T-cell receptor (TCR) 2,3. Upon ligand binding, proximal signaling events converge at the Iκ B kinase (IKK) complex, which acts as the gatekeeper of NF-κ B signaling by phosphorylating and inactivating the inhibitors of NF-κ B (Iκ Bs). The IKK complex consists of two catalytic subunits IKKα /IKKβ and the regulatory subunit IKKγ /NEMO (NF-κ B essential modulator) 4. The IKK regulatory subunit NEMO serves as a critical integrating platform that couples upstream receptor signaling complexes to the catalytic IKKs 5,6. Biochemical and genetic studies have highlighted a pivotal function of poly-ubiquitination for IKK/NF-κ B activation. It has been shown that IKK upstream signaling adaptors like RIP1 (TNFR), IRAK1/4 (IL-1R) or MALT1 (TCR) are modified by ubiquitin (Ub) chains to recruit NEMO and thereby promote IKK activation 2,7,8. Assembly of Met1-linked (linear) Ub chains by the LUBAC (linear Ub assembly complex) is also essential for IKK/NF-κ B activation in response to various stimuli 9–12 .

Co-stimulatory CD28 and transcription factor NFKB1 genes are considered as a crucial player in the determination of inflammatory responses; genetic variability in these may modulate the risk for idiopathic recurrent miscarriages (IRM). We investigated the association of functional variants of CD28 (rs3116496 T/C) and NFKB1 (rs28362491 ins/del and rs696 A/G) with IRM cases. We recruited 200 IRM women with a history of at least three consecutive pregnancy losses before 20th week of pregnancy and 300 fertile control women. Determination of CD28 (rs3116496 T/C) and NFKB1 (rs28362491 ins/del and rs696 A/G) gene variants were based on the polymerase chain reaction pursued by restriction fragment length polymorphism analysis and validated with Sanger sequencing. Single marker analysis and multifactor dimensionality reduction (MDR) model used to predict the IRM risk. We observed nearly three- to twofold increased risk in single marker analysis for minor homozygous genotypes of rs3116496 T/C...

Oxidative stress, inflammation and androgen receptor (AR) signaling play a pivotal role in the initiation, development and progression of prostate cancer (PCa). Numerous papers in the literature have documented the interconnection between oxidative stress and inflammation; and how antioxidants can combat the inflammation. It has been shown in the literature that both oxidative stress and inflammation regulate AR, the key receptor involved in the transition of PCa to castration resistant prostate cancer (CRPC). In this review, we discuss about the importance of targeting Nrf-2-antioxidant signaling, NF-κB inflammatory response and AR signaling in PCa. Finally, we discuss about the crosstalk between these three critical pathways as well as how the anti-inflammatory antioxidant phytochemicals like sulforaphane (SFN) and curcumin (CUR), which can also target AR, can be ideal candidates in the chemoprevention of PCa.

Several studies underline the role of the transcription factor NF-κB in the development of left cardiac hypertrophy (LVH). We have demonstrated recently that the RGS homology domain within the amino terminus of GRK5 (GRK5-NT) is able to inhibit NF-κB transcription activity and its associated phenotypes. The aim of this study was to evaluate the ability of GRK5-NT to regulate LVH through the inhibition of NF-κB both in vitro and in vivo. In cardiomyoblasts, GRK5-NT inhibits phenylephrine-induced transcription of both NF-κB and atrial natriuretic factor promoters, assessed by luciferase assay, thus confirming a role for this protein in the regulation of cardiomyocyte hypertrophy. In vivo, we explored 2 rat models of LVH, the spontaneously hypertensive rat and the normotensive Wistar Kyoto rat exposed to chronic administration of phenylephrine. Intracardiac injection of an adenovirus encoding for GRK5-NT reduces cardiac mass in spontaneously hypertensive rats and prevents the development of phenylephrine-induced LVH in Wistar Kyoto rats. This associates with inhibition of NF-κB signaling (assessed by NF-κB levels), transcriptional activity and phenotypes (fibrosis and apoptosis). Such phenomenon is independent from hemodynamic changes, because adenovirus encoding for GRK5-NT did not reduce blood pressure levels in spontaneously hypertensive rats or in Wistar Kyoto rats. In conclusion, our study supports the regulation of LVH based on the GRK5-NT inhibition of the NF-κB transduction signaling.

Chromosomal rearrangement involving 14q32 region that results in TNF receptor associated factor 3 (TRAF3) dysfunctional mutation is the most frequent NF-κB pathway mutation in multiple myeloma (MM). Subsequent NF-κB inducing Kinase (NIK) stabilization plays a critical role in alternative NF-κB activation. However, disease progression resulting from TRAF3 dysregulation has not been well understood. In this study, we identified lymphocyte cellular protein 1 (LCP1) as a novel NIK-driven alternative NF-κB target in TRAF3 dysfunctional mutation using RNA-seq, ChIP-seq (RelA/p65 and p52 NF-κB) and other validation methods. LCP1 is exclusively activated in MM cells with TRAF3 loss-of-function mutation. In MM patients, higher LCP1 expression was significantly pronounced in poor prognosis groups such as 4p16 and MAF. CD138 negative MM patient cells showed elevated LCP1 expression and inhibition of LCP1 can sensitize proteasome inhibitor bortezomib in TRAF3 mutant MM cells in vitro. We report that LCP1 is a NIK-driven biomarker in TRAF3 dysfunctional MM and targeting LCP1 can provide a valuable therapeutic intervention in TRAF3 mutated MM.

Filoviruses are highly lethal in humans and nonhuman primates, likely due to potent antagonism of host interferon (IFN) responses early in infection. Filoviral protein VP35 is implicated as the major IFN induction antagonist, while Ebola virus (EBOV) VP24 or Marburg virus (MARV) VP40 are known to block downstream IFN signaling. Despite progress elucidating EBOV and MARV antagonist function, those for most other filoviruses, including Reston (RESTV), Sudan (SUDV), Taï Forest (TAFV), Bundibugyo (BDBV) and Ravn (RAVV) viruses, remain largely neglected. Thus, using standardized vectors and reporter assays, we characterized activities by each IFN antagonist from all known ebolavirus and marburgvirus species side-by-side. We uncover noncanonical suppression of IFN induction by ebolavirus VP24, differing potencies by MARV and RAVV proteins, and intriguingly, weaker antagonism by VP24 of RESTV. These underlying molecular explanations for differential virulence in humans could guide future investigations of more-neglected filoviruses as well as treatment and vaccine studies.

G protein coupled receptor kinase type 2 (GRK2)
plays an important role in the development and maintenance
of cardiac hypertrophy and heart failure even if its exact role is
still unknown. In this study, we assessed the effect of GRK2
on the regulation of cardiac hypertrophy. In H9C2 cells,
GRK2 overexpression increased atrial natriuretic factor
(ANF) activity and enhanced phenylephrine-induced ANF response,
and this is associated with an increase of NFκB transcriptional
activity. The kinase dead mutant and a synthetic
inhibitor of GRK2 activity exerted the opposite effect, suggesting
that GRK2 regulates hypertrophy through upregulation
of NFκB activity in a phosphorylation-dependent manner.
In two different in vivo models of left ventricle hypertrophy
(LVH), the selective inhibition of GRK2 activity prevented
hypertrophy and reduced NFκB transcription activity. Our
results suggest a previously undisclosed role for GRK2 in
the regulation of hypertrophic responses and propose GRK2
as potential therapeutic target for limiting LVH.

ÖZET: Inflamatuar ortam hücresel stresi tetikler. Aynı şekilde hücresel stres inflamatuar mediyatörlerin salgılanmasını uyararak hücresel stresi tetikler. Hücresel stres mekanizmaları hücresel yaşlanmayı tetikleyerek hücresel fonksiyonları baskılar. Artan hücre stresi, reaktif oksijen ürünlerinin ve inflamatuar sitokinlerin uyarısıyla, tümor supresor genlerin aktivasyonunun artmasına neden olur.Tumor supresor genlerle uyarılan JNK, p53 gibi bazı faktörler; onkogenlerle uyarılan PI3K, Akt, ras, raf gibi faktörleri antagonize ederek işlevlerini baskılamaya çalışır. Tumor supresor faktörlerin işlevi; hücre metabolizması, sağkalımı ve proliferasyonu gibi yaşamsal faaliyetleri yöneten onkogenlerle ilişkili faktörlerin baskılanmasına yol açar. Böylece,kronik inflamatuar ortamda aşırı sitokin uyarısıyla yaşlanması tetiklenmiş hücreler fonksiyonlarını yerine getiremez.Bu yaşlanmış hücrelerden oluşan dokuların fonksiyon kaybı nedeniyle, vucuttaki lipit ve glikoz gibi metabolitlerin hücrelerde metabolize edilmesi baskılanmış olur. Plazmada biriken metabolitler reaktif oksijen ürünleriyle etkileşerek Toll Like Reseptörleri(TLR) uyarır. TLR uyarısı NfkB bağımlı hücre stresini ve stresle ilişkili hücresel yaşlanmayı daha da artırır.Dokuların fonksiyon kaybıyla metabolik olaylar baskılanır, glikoz ve lipit gibi metabolitlerin kan plazmasındaki derişimi artar.Bu mekanizmanın Insulin direnci-Tip 2 Diyabet ve Ateroskleroz gelişim patogenezinde yer aldığı düşünülmüştür. Sirtuin(SIRT) agonistleri, NfkB bağımlı hücresel stresi baskılar. SIRT ile NfkB'nin baskılanması inflamatuar sitokin üretimini engelleyerek organizmada inflamatuar stres bağımlı hücresel yaşlanma gelişiminin yavaşlatılmasını sağlar, bu sayede doku fonksiyonlarının korunmasına yardım edebilir. Böylece SIRT agonistleri Tip 2 diyabet ve aterosklerozun kombine tedavisinde kullanılabilir.

Toxicity associated with systemic administration of adenoviral vectors occurs in three phases: acute, intermediate and chronic. Chronic toxicity has largely been abolished with the application of
helper-dependent vectors (HDV). However, the acute toxicity induced by both early generation and helper-dependent adenoviral vectors continues to be a major obstacle for clinical application in humans. We are utilizing microarray technology to determine alterations in gene expression patterns that are brought about in vitro and in vivo by infection with both first generation and helper-dependent adenoviral vectors. Signaling pathways that are activated by Ad infection may contribute to the host innate immune response. These same pathways would be targets for pharmacologic manipulations aimed at decreasing acute toxicity and improving the therapeutic index of HDVs.
We have performed preliminary in vitro analyses using RNA collected 24 hours after infection of Human Umbilical Vein Endothelial Cells (HUVEC) with PBS, First Generation or Helper-Dependent adenoviral vectors. This RNA was reverse transcribed and hybridized to either Affymetrix oligo arrays or NFκB pathway arrays. HUVECs represent a relevant target cell type based on substantial endothelial cell transduction following intravenous adenoviral vector administration observed in nonhuman primates, while the NFκB pathway has been implicated in host innate immune response to adenoviral vector by our lab and several others. The Affymetrix chips offer a genome-wide analysis of expression pattern alterations, while the NFκB targeted array has been specifically designed to include 112 genes associated with the NFκB signaling network.
Data from the NFκB pathway array suggests that of the 112 spotted genes, approximately 40 genes undergo at least a two-fold induction in helper-dependent vector-infected HUVECs as compared to mock-infected HUVECs. These genes include several TLRs, TRAFs and interferons alpha and beta. On first pass, these data support modulation of NFκB signaling in target cells as a potential approach for addressing acute toxicity of Ad vectors.
Current in vitro experiments are addressing additional cell types including hepatocytes and dendritic cells from both mouse and human.

SUMMARY Non-dysplastic Barrett's oesophagus (NDBE) occurs as a consequence of an inflam-matory response triggered through prolonged gastro-oesophageal reflux and it may precede the development of oesophageal adenocarcinoma. NF-kB activation as a result of inflammatory response has been shown in NDBE, but the possible mechanism involved in the process is unknown. The aim of this study was to assess, using immunohistochemistry, Survivin and Bcl3 expression as potential biomarkers for NF-kB activation along the oesophageal metaplasia–dysplasia–adenocarcinoma sequence. Survivin is an NF-kB-inducible anti-apoptotic protein, and Bcl3 is a negative regulator of NF-kB. There was progressive upregulation of Survivin expression along the oesophageal metaplasia–dysplasia–adenocarcinoma sequence. Bcl3 expression was upregulated in non-dysplastic Barrett's oesophagus, low-grade, high-grade dysplasia and oesophageal adenocarcinoma when compared to squamous group. The study shows the differential expression of Bcl3 between the squamous and Barrett's stage, suggesting that Bcl3 could be a surrogate marker for early event involving constitutive NF-kB activation. In addition, the study suggests that NF-jB activation may infer resistance to apoptosis through the expression of anti-apoptotic genes such as Survivin, which showed progressive increase in expression throughout the oeso-phageal metaplasia–dysplasia–adenocarcinoma sequence. This ability to avoid apop-tosis may underlie the persistence and malignant predisposition of Barrett's metaplasia.

The innate immune system protects against infections
by initiating an inducible inflammatory response.
NF-kappa B (NF-KB) is one of the critical
transcription factors controlling this complex
response, but some aspects of its regulation remain
unclear. For example, although long noncoding
RNAs (lncRNAs) have been shown to critically
regulate gene expression, only a fraction of
these have been functionally characterized, and the
extent to which lncRNAs control NF-KB expression
is unknown. Here, we describe the generation
of a GFP-based NF-KB reporter system in immortalized
murine bone marrow–derived macrophages
(iBMDMs). Activation of this reporter, using Tolllike
receptor ligands, resulted in GFP expression,
which could be monitored by flow cytometry. We
also established a CRISPR/Cas9 gene deletion system
in this NF-KB reporter line, enabling us to
screen for genes that regulate NF-KB signaling. Our
deletion-based approach identified two long intergenic
noncoding (linc)RNAs, lincRNA-Cox2 and
lincRNA-AK170409, that control NF-KB signaling.
We demonstrate a potential novel role for lincRNACox2
in promoting IkBA degradation in the cytoplasm.
For lincRNA-AK170409, we provide evidence
that this nuclear-localized lincRNA regulates
a number of inflammation-related genes. In conclusion,
we have established an NF-KB–GFP iBMDM
reporter cell line and a line that stably expresses
Cas9. Our approach enabled identification
of lincRNA-Cox2 and lincRNA-AK170409 as NFKB
regulators and this tool will be useful for identifying
additional genes involved in regulating this
transcription factor critical for immune function.

A commercial aqueous stem bark extract of Mangifera indica L. (Vimang®) has been reported to have antiinflammatory, immunomodulatory and antioxidant activities. The molecular basis for these diverse properties is still unknown. This study shows that a stem bark extract of M. indica inhibits early and late events in T cell activation, including CD25 cell surface expression, progression to the S-phase of the cell cycle and proliferation in response to T cell receptor (TCR) stimulation. Moreover, the extract prevented TNFα-induced IκBα degradation and the binding of NF-κB to the DNA. This study may help to explain at the molecular level some of the biological activities attributed to the aqueous stem bark extract of M. indica (Vimang®). Copyright © 2005 John Wiley & Sons, Ltd.

Endotoxin (LPS)-induced changes in histone lysine methylation contribute to the gene-specific transcription for control of inflammation. Still unidentified are the chromatin regulators that drive the transition from a transcriptional-repressive to a transcriptional-active chromatin state of pro-inflammatory genes. Here, using combined approaches to analyze LPS-induced changes in both gene-specific transcription and protein secretion to the extracellular compartment, we characterize novel functions of the lysine demethylase PHF8 as a pro-inflammatory, gene-specific chromatin regulator. First, in the LPS-induced, acute-inflamed macrophages, PHF8 knockdown led to both a reduction of pro-inflammatory factors and an increase in a transcriptional-repressive code (H3K9me2) written by the methyltransferase G9a. Through unbiased quantitative secretome screening we discovered that LPS induces the secretion of a cluster of PHF8-dependent, 'tolerizable' proteins that are related to diverse extracellular pathways/processes including those for the activation of adaptive immunity. Specifically, we determined that PHF8 promotes T-cell activation and proliferation, thus providing the first link between the epigenetic regulation of inflammation and adaptive immunity. Further, we found that, in the acute-inflamed macrophages, the acute-active PHF8 opposes the H3K9me1/2-writing activity of G9a to activate specific protein secretions that are suppressed by G9a in the endotoxin-tolerant cells, revealing the inflammatory-phenotypic chromatin drivers that regulate the gene-specific chromatin plasticity. Activation of inflammation, the key host innate immune response to microbial challenge 1 , is a double-edged sword; it protects the host from infection and cellular damage, yet, its deregulation contributes directly to various inflammation-associated pathologies 2,3. Previous studies indicated that control of inflammation is achieved by endotoxin-or lipopolysaccharide (LPS)-induced gene-specific chromatin modifications. The landscape of promoter chromatin modifications is differentially programmed for a class of pro-inflammatory or " tolerizeable " (T-class) genes, in correlation with either acutely or chronically inflamed nature or " inflammatory-phenotype " of the stimulated cells 4. However, how inflammation-phenotypic plasticity is regulated within the chromatin of pro-inflammatory genes is poorly understood. The properties of histones, the core components of chromatin, can be altered by different post-translational modifications (PTMs) that specify whether the promoter of associated gene is in an open/active or closed/

Previous studies have shown significant changes in amyloid-b (Ab) transport across the blood-brain barrier (BBB) under diabetic conditions with hypoinsulinemia, which is involved in diabetes-associated cognitive impairment. Present study employed db/db mice with hyperinsulinemia to investigate changes in Ab transport across the BBB, hippocampal synaptic plasticity, and restorative effects of antidiabetic drugs. Our results showed that db/db mice exhibited similar changes in Ab transport across the BBB to that of insulin-deficient mice. Chronic treatment of db/db mice with antidiabetic drugs such as metformin, glibenclamide and insulin glargine significantly decreased Ab influx across the BBB determined by intra-arterial infusion of 125 I-Ab 1-40 , and expression of the receptor for advanced glycation end products (RAGE) participating in Ab influx. Insulin glargine, but not, metformin or glibenclamide increased Ab efflux across the BBB determined by stereotaxic intra-cerebral infusion of 125 I-Ab 1-40 , and expression of the low-density lipoprotein receptor related protein 1 (LRP1) participating in Ab efflux. Moreover, treatment with these drugs significantly decreased hippocampal Ab 1-40 or Ab 1-42 and inhibited neuronal apoptosis. The drugs also ameliorated memory impairment confirmed by improved performance on behavioral tasks. However, insulin glargine or glibenclamide, but not metformin, restored hippocampal synaptic plasticity characterized by enhancing in vivo long-term potentiation (LTP). Further study found that these three drugs significantly restrained NF-kB, but only insulin glargine enhanced peroxisome proliferator-activated receptor g (PPARg) activity at the BBB in db/db mice. Our data indicate that the antidiabetic drugs can partially restore abnormal Ab transport across the BBB and memory impairment under diabetic context.

G protein coupled receptor kinase type 2 (GRK2) plays an important role in the development and maintenance of cardiac hypertrophy and heart failure even if its exact role is still unknown. In this study, we assessed the effect of GRK2 on the regulation of cardiac hypertrophy. In H9C2 cells, GRK2 overexpression increased atrial natriuretic factor (ANF) activity and enhanced phenylephrine-induced ANF response, and this is associated with an increase of NFκB transcriptional activity. The kinase dead mutant and a synthetic inhibitor of GRK2 activity exerted the opposite effect, suggesting that GRK2 regulates hypertrophy through upregulation of NFκB activity in a phosphorylation-dependent manner. In two different in vivo models of left ventricle hypertrophy (LVH), the selective inhibition of GRK2 activity prevented hypertrophy and reduced NFκB transcription activity. Our results suggest a previously undisclosed role for GRK2 in the regulation of hypertrophic responses and propose GRK2 as...

Regardless of abundant efforts to enhance primary prevention and early detection, the number of melanoma cases in the United States has increased steadily over the past 15 years, thus greatly affecting public health and the economy. In previous studies, we demonstrated protein kinase C-ι (PKC-ι) to be an oncogene in melanoma, which promotes the activation of nuclear factor (NF)-κB, thereby supporting survival and progression. In addition, we demonstrated that PKC-ι induced the metastasis of melanoma cells by activating Vimentin, and PKC-ι inhibition downregulated epithilial-mesencymal transition (EMT), while inducing apoptosis. Of note, PKC-ι specific inhibitors downregulated the expression of both PKC-ι and phosphorylated PKC-ι, suggesting that PKC-ι plays a role in regulating its own expression in melanoma. In this study, we report the underlaying mechanisms of the transcriptional regulation of PKC-ι (PRKCI gene) expression in melanoma. c-Jun, interferon-stimulated gene factor 3 (ISGF3), paired box gene 3 (PAX3), early growth response protein 1 (EGR1) and Forkhead box protein O1 (FOXO1), which bind on or near the promoter sequence of the PRKCI gene, were analyzed for their role in PKC-ι regulation in SK-MEL-2 and MeWo cell lines. We silenced selected transcription factors using siRNA, and the results revealed that the silencing of c-Jun and FOXO1 significantly altered the expression of PRKCI. The levels of both phosphorylated and total PKC-ι increased upon FOXO1 silencing and decreased upon c-Jun silencing, suggesting that c-Jun acts as an upregulator, while FOXO1 acts as a down-regulator of PRKCI expression. We also used a multiplex ELISA to analyze multiple pathways other than NF-κB that were affected by treatment with PKC-ι inhibitor. The silencing of NF-κB p65 and PKC-ι by siRNA suggested that the regulation of PKC-ι expression was strongly associated with FOXO1. In addition, we observed a significant decrease in the mRNA levels of both interleukin (IL)-6 and IL-8, with a significant increase in the levels of IL-17E and intercellular adhesion molecule 1 (ICAM-1) upon the knockdown of expression of PKC-ι in both cell lines. This suggested that PKC-ι expression was affected by these cytokines in an autocrine manner. Overall, the findings of this study suggest that PKC-ι inhibition suppresses its own expression, diminishing oncogenic signaling, while upregulating anti-tumor signaling, thus rendering it an effective novel biomarker for use in the design of novel targeted therapeutics for melanoma.

Inflammation triggers cellular stress which induces secretion of inflammatory mediators.Mechanisms of cellular stress triggers cellular senescence that suppresses physiological funcitons of cells. A type of antagonism occurs among tumor suppressor genes and oncogenes.Tumor supressor genes related factors, suppress oncogenes related factors in generally. Increased cell stress causes stimulation of tumor suppressor factors by inflammatory cytokines and reactive oxygene species(ROS).In chronic inflammatory environment, stimulation by excessive cytokines lead to cellular senescence. Tissue disfunctions which are triggered by cellular senescence, cause suppression of metabolic pathways for some glucose and lipid derived metabolites. Accumulated metabolites in extracellular matrix or plasma, oxidized metabolites stimulate several types of Toll Like Receptors(TLRs) which stimulate NfkB dependent cellular stress this causes more accelarated cellular senescence.This physiopathology may trigger Insulin resistance,diabetes and atherosclerosis, and other senescence related diseases like osteoarthrits. Sirtuin(SIRT) agonists can suppress NfkB dependent cellular stress. Suppressing of NfkB by SIRT may decrease inflammatory cytokine production which leads to decreasing of cellular senescence.Thus,SIRT agonists may help protection of tissue and organ functions. SIRT agonists maybe a new therapeautic target for combined therapy of Insulin resistance-Type 2 diabetes mellitus and atherosclerosis.

A commercial aqueous stem bark extract of Mangifera indica L. (Vimang®) has been reported to have antiinflammatory, immunomodulatory and antioxidant activities. The molecular basis for these diverse properties is still unknown. This study shows that a stem bark extract of M. indica inhibits early and late events in T cell activation, including CD25 cell surface expression, progression to the S-phase of the cell cycle and proliferation in response to T cell receptor (TCR) stimulation. Moreover, the extract prevented TNFα-induced IκBα degradation and the binding of NF-κB to the DNA. This study may help to explain at the molecular level some of the biological activities attributed to the aqueous stem bark extract of M. indica (Vimang®). Copyright © 2005 John Wiley & Sons, Ltd.

Glucosamine (GlcN) is used in the treatment of osteoarthritis as symptomatic slow-acting drug, but its mode of action is not completely known. We analyzed the influence of GlcN and its N-acetyl-phenylalanine derivative (NAPA) on mRNA transcription level of TNF-alpha-stimulated genes in cell culture. Human immortalized chondrocyte cell line lbpva55 was stimulated with TNF-alpha and treated with GlcN and NAPA. mRNA transcription level of several genes, identified by complementary DNA microarray (cDNA microarray), was validated by Quantitative Real-Time Polymerase Chain Reaction (Q-RT-PCR). Several genes, whose mRNA level was increased by TNF-alpha treatment and significantly reduced by GlcN and NAPA in lbpva55 cells, were identified. These include cytokine receptors TNF-R1 and TNF-R2, their associated factor TRAF-6, signaling intermediates IGFB-6 and Rnd1, as well as cell cycle regulating proteins CUL-2 and G1S protein 1. Down- regulation of mRNA expression level of some of these gene...

Reactive astrocytes have been implicated in neuronal loss following ischemic stroke. However, the molecular mechanisms associated with this process are yet to be fully elucidated. In this work, we tested the hypothesis that astroglial NF-κB, a key regulator of inflammatory responses, is a contributor to neuronal death following ischemic injury. We compared neuronal survival in the ganglion cell layer (GCL) after retinal ischemia-reperfusion in wild-type (WT) and in GFAP-IκBα-dn transgenic mice, where the NF-κB classical pathway is suppressed specifically in astrocytes. The GFAP-IκBα-dn mice showed significantly increased survival of neurons in the GCL following ischemic injury as compared with WT littermates. Neuroprotection was associated with significantly reduced expression of pro-inflammatory genes, encoding Tnf-α, Ccl2 (Mcp1), Cxcl10 (IP10), Icam1, Vcam1, several subunits of NADPH oxidase and NO-synthase in the retinas of GFAP-IκBα-dn mice. These data suggest that certain NF-κB-regulated pro-inflammatory and redox-active pathways are central to glial neurotoxicity induced by ischemic injury. The inhibition of these pathways in astrocytes may represent a feasible neuroprotective strategy for retinal ischemia and stroke.