The NF-kappaB pathway

Selective protein detection with a dsLNA-functionalized nanopore

In the last years, nanopore technology has been increasingly exploited for biomolecule detection and analysis. Recently, the main focus of the research has moved from the study of nucleic acids to the analysis of proteins and DNA-protein complexes. In this paper, chemically functionalized solid-state nanopore has been used to recognize Nuclear Factor-kappa B proteins (NF-κB), that are involved in several disorders and inflammation processes, so that their identification is of crucial importance for prognostic applications. In particular, we show that it is possible to electrically detect the specific interaction between p50, a protein belonging to the NF-κB family, and dsLNA probe molecules covalently attached to the surface of a FIB fabricated SiN pore. The obtained results have been compared with those related to BSA protein, which does not interact with the used probes. Finally, the potential of the device has been further tested by analyzing a whole cell extract. In this case, three principal peaks in the distribution of electrical event duration can be identified, corresponding to different interacting NF-κB complexes, so that the methodology appears to be effective also to study biological samples of considerable complexity. Ultimately, the presented data emphasize the selectivity and versatility of the functionalized nanopore device, demonstrating its applicability in bioanalytics and advanced diagnostics.

Diethylcarbamazine inhibits NF-κB activation in acute lung injury induced by carrageenan in mice

Diethylcarbamazine citrate (DEC) is widely used to treat lymphatic filariasis and Tropical Pulmonary Eosinophilia. A number of studies have reported a possible role in the host immune system, but exactly how DEC exerts this effect is still unknown. The present study reports the effects of DEC pretreatment on NF-κB regulation using the pleurisy model induced by carrageenan. Swiss male mice (Mus musculus) were divided into four experimental groups: control (SAL); carrageenan (CAR); diethylcarbamazine (DEC) and curcumin (CUR). The animals were pretreated with DEC (50mg/kg, v.o), CUR (50mg/kg, i.p) or distilled water for three consecutive days before pleurisy. One way analysis of variance (ANOVA) was performed by Tukey post-hoc test, and values were considered statistically significant when p<0.05. DEC pretreatment reduced tissue damage and the production of inflammatory markers, such as NO, iNOS, PGE2, COX-2, and PARP induced by carrageenan. Similarly, a known inhibitor of NF-κB pathway (curcumin) was also able to reduce these parameters. Like curcumin, DEC prevents NF-κB activation by reducing NF-κB p65 phosphorylation and IκBα degradation. DEC prevented NF-κB activation via p38 MAPK, but did not interfere in the ERK pathway in this experimental model. However, further studies should be developed to confirm this hypothesis. These findings suggest that DEC could be a promising drug for inflammatory disorders, especially in pulmonary diseases such as Acute Lung Inflammation, due its high anti-inflammatory potential which prevents NF-κB activation.

Penta-O-galloyl-β-D-glucose ameliorates inflammation by inhibiting MyD88/NF-κB and MyD88/MAPK signalling pathways

BACKGROUND AND PURPOSE

The gallnut of Rhus chinensis MILL and its main constituent penta-O-galloyl-β-D-glucose (PGG) inhibited NF-κB activation in LPS-stimulated peritoneal and colonic macrophages. Here we have investigated PGG mechanisms underlying anti-inflammatory effects of PGG in vitro and in vivo.

EXPERIMENTAL APPROACH

Male C57BL/6 mice (18-22 g, 6 weeks old) were used to prepare peritoneal and colonic macrophages and for the induction of colitis by intrarectal administration of 2,3,4-trinitrobenzene sulphonic acid (TNBS). A range of inflammatory markers and transcription factors were evaluated by elisa, immunoblotting, flow cytometry and confocal microscopy.

KEY RESULTS

Expression of Toll-like receptor (TLR)-4 or Lipopolysaccharide (LPS) binding to TLR-4 in LPS-stimulated peritoneal macrophages was not affected by PGG. However PGG inhibited binding of an anti-MyD88 antibody to peritoneal macrophages, but did not reduce binding of anti-IL-1 receptor-associated kinase (IRAK1) and IRAK4 antibodies to the macrophages with or without transfection with MyD88 siRNA. PGG potently reduced the activation of IRAK1, NF-κB, and MAPKs in LPS- or pepetidoglycan-stimulated peritoneal and colonic macrophages. PGG suppressed IL-1β, TNF-α and IL-6 in LPS-stimulated peritoneal macrophages, while increasing expression of the anti-inflammatorycytokine IL-10. Oral administration of PGG inhibited colon shortening and myeloperoxidase activity in mice with TNBS-induced colitis, along with reducing NF-κB activation and IL-1β, TNF-α, and IL-6 levels, whereas it increased IL-10.

CONCLUSIONS AND IMPLICATIONS

PGG reduced activation of NF-κB and MAPK signalling pathways by directly interacting with the MyD88 adaptor protein. PGG may ameliorate inflammatory diseases such as colitis.

A novel NF-κB inhibitor, DHMEQ, ameliorates pristane-induced lupus in mice

Nuclear factor (NF)-κB is strongly associated with the development of immune regulation and inflammation. The aim of the present study was to identify whether a NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), ameliorates systemic lupus erythematosus (SLE) in a pristane-induced mouse model. SLE was induced in 8-week-old female BALB/c mice by the injection of 0.5 ml pristane. The therapeutic effect of 12 mg/kg DHMEQ on the pristane-induced BALB/c mouse model of lupus was investigated to elucidate the effects on SLE. The intraperitoneal administration of DHMEQ three times per week was initiated when the mice were 16 weeks-old (8 weeks following the pristane injection) and the treatment was continued for 16 weeks. Serum IgG autoantibodies against nucleosomes, dsDNA and histones were detected at weeks 8, 16 and 32. In addition, the expression levels of interleukin (IL)-1β, 6 and 17, as well as tumor necrosis factor (TNF)-α, were analyzed at week 32. Renal lesions were also observed. DHMEQ was shown to antagonize the increasing levels of anti-nucleosome, anti-dsDNA and anti-histone autoantibodies, as well as the increasing levels of IL-1β, 6 and 17 and TNF-α. In addition, DHMEQ reduced the number of renal lesions caused by pristane, as reflected by milder proteinuria and reduced renal pathology. The renal expression levels of phosphorylated-p38 mitogen-activated protein kinase (MAPK), phosphorylated-c-Jun N-terminal kinase (JNK) and NF-κB p65 were significantly downregulated. Therefore, the results of the present study indicate that DHMEQ has a beneficial effect on pristane-induced lupus through regulating cytokine levels and the MAPK/JNK/NF-κB signaling pathway.

Immune regulation and anti-inflammatory effects of isogarcinol extracted from Garcinia mangostana L. against collagen-induced arthritis

Isogarcinol is a natural compound that we extracted from Garcinia mangostana L., and we were the first to report that it is a new immunosuppressant. In the present study, we investigated the immune regulation and anti-inflammatory effects of isogarcinol on collagen-induced arthritis (CIA) and explored its potential mechanism in the treatment of rheumatoid arthritis. The oral administration of isogarcinol significantly reduced clinical scores, alleviated cartilage and bone erosion, and reduced the levels of serum inflammatory cytokines in CIA mice. Isogarcinol inhibited xylene-induced mouse ear edema in vivo. In vitro, isogarcinol decreased iNOS and COX-2 mRNA expression and NO content by inhibiting NF-κB expression. Furthermore, isogarcinol decreased the activity of NFAT and inhibited IL-2 expression. The mechanism of action of isogarcinol is associated with down-regulation of both autoimmune and inflammatory reactions.

Wild-type uromodulin prevents NFkB activation in kidney cells, while mutant uromodulin, causing FJHU nephropathy, does not

BACKGROUND

Uromodulin (Tamm-Horsfall protein) is the most abundant urinary protein in healthy individuals. Despite 60 years of research, its physiological role remains rather elusive. Familial juvenile hyperuricemic nephropathy and medullary cystic kidney disease Type 2 are autosomal dominant tubulointerstitial nephropathies characterized by gouty arthritis and progressive renal insufficiency, caused by uromodulin (UMOD) mutations. The aim of this study was to compare the cellular effects of mutant and wild-type UMOD.

METHODS

Wild-type UMOD cDNA was cloned from human kidney cDNA into pcDNA3 expression vector. A mutant UMOD construct, containing the previously reported mutation, V273, was created by in vitro mutagenesis. Transient and stable transfection studies were performed in human embryonic kidney cells and mouse distal convoluted tubular cells, respectively. Expression was evaluated by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunofluorescence. Oligosaccharide cleavage by glycosidases was performed to characterize different forms of UMOD. Nuclear translocation of P65 and degradation of IκBα and IRAK1 in response to interleukin (IL)-1β were used to evaluate the effects of wild-type and mutant UMOD on the IL-1R-NFκB pathway.

RESULTS

The mutant protein was shown to be retained in the endoplasmic reticulum and was not excreted to the cell medium, as opposed to the wild-type protein. NFκB activation in cells expressing mutant UMOD was similar to that of untransfected cells. In contrast, cells over-expressing wild-type UMOD showed markedly reduced NFκB activation.

CONCLUSION

Our findings suggest that UMOD may have a physiologic function related to its inhibitory effect on the NFκB pathway.

Inhibitors of NF-kappaB reverse cellular invasion and target gene upregulation in an experimental model of aggressive oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is diagnosed in 640,000 patients yearly with a poor (50%) 5-year survival rate that has not changed appreciably in decades.

PAITENTS AND METHODS

To investigate molecular changes that drive OSCC progression, cDNA microarray analysis was performed using human OSCC cells that form aggressive poorly differentiated tumors (SCC25-PD) in a murine orthotopic xenograft model compared to cells that produce well-differentiated tumors (SCC25-WD).

RESULTS

As this analysis revealed that 59 upregulated genes were NF-κB target genes, the role of NF-κB activation in alteration of the transcriptional profile was evaluated. The mRNA and protein upregulation of a panel NF-κB target genes was validated by real-time qPCR and immunohistochemistry. Additionally, nuclear translocation of RelA was greatly increased in SCC25-PD, increased nuclear RelA was observed in oral tumors initiated with SCC25-PD compared with tumors initiated by SCC25-WD, and nuclear RelA correlated with stage of disease on two human OSCC tissue microarrays. Treatment of SCC25-PD cells with the IKKβ-inhibitor sc-514, that effectively prevents RelA phosphorylation on Ser 536, reversed nuclear-translocation of RelA and strongly inhibited NF-κB gene activation. Furthermore, blocking the phosphorylation of RelA using the MSK1/2 inhibitor SB 747651A significantly reduced the mRNA upregulation of a subset of target genes. Treatment with sc-514 or SB747651A markedly diminished cellular invasiveness.

CONCLUSIONS

These studies support a model wherein NF-κB is constitutively active in aggressive OSCC, while blocking the NF-κB pathway reduces NF-κB target gene upregulation and cellular invasiveness.

TWEAK/Fn14 and Non-Canonical NF-kappaB Signaling in Kidney Disease

The incidence of acute kidney injury (AKI) and chronic kidney disease (CKD) is increasing. However, there is no effective therapy for AKI and current approaches only slow down, but do not prevent progression of CKD. TWEAK is a TNF superfamily cytokine. A solid base of preclinical data suggests a role of therapies targeting the TWEAK or its receptor Fn14 in AKI and CKD. In particular TWEAK/Fn14 targeting may preserve renal function and decrease cell death, inflammation, proteinuria, and fibrosis in mouse animal models. Furthermore there is clinical evidence for a role of TWEAK in human kidney injury including increased tissue and/or urinary levels of TWEAK and parenchymal renal cell expression of the receptor Fn14. In this regard, clinical trials of TWEAK targeting are ongoing in lupus nephritis. Nuclear factor-kappa B (NF-κB) activation plays a key role in TWEAK-elicited inflammatory responses. Activation of the non-canonical NF-κB pathway is a critical difference between TWEAK and TNF. TWEAK activation of the non-canonical NF-κB pathways promotes inflammatory responses in tubular cells. However, there is an incomplete understanding of the role of non-canonical NF-κB activation in kidney disease and on its contribution to TWEAK actions in vivo.

Aromadendrin Inhibits Lipopolysaccharide-Induced Nuclear Translocation of NF-κB and Phosphorylation of JNK in RAW 264.7 Macrophage Cells

Aromadendrin, a flavonol, has been reported to possess a variety of pharmacological activities such as anti-inflammatory, antioxidant, and anti-diabetic properties. However, the underlying mechanism by which aromadendrin exerts its biological activity has not been extensively demonstrated. The objective of this study is to elucidate the anti-inflammatory mechanism of aromadedrin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Aromadendrin significantly suppressed LPS-induced excessive production of pro-inflammatory mediators such as nitric oxide (NO) and PGE2. In accordance, aromadendrin attenuated LPSinduced overexpression iNOS and COX-2. In addition, aromadendrin significantly suppressed LPS-induced degradation of IκB, which sequesters NF-κB in cytoplasm, consequently inhibiting the nuclear translocation of pro-inflammatory transcription factor NF- κB. To elucidate the underlying signaling mechanism of anti-inflammatory activity of aromadendrin, MAPK signaling pathway was examined. Aromadendrin significantly attenuated LPS-induced activation of JNK, but not ERK and p38, in a concentration-dependent manner. Taken together, the present study clearly demonstrates that aromadendrin exhibits anti-inflammatory activity through the suppression of nuclear translocation of NF-κB and phosphorylation of JNK in LPS-stimulated RAW 264.7 macrophage cells.

The immune-enhancing effect of the Cronobacter sakazakii ES2 phage results in the activation of nuclear factor-κB and dendritic cell maturation via the activation of IL-12p40 in the mouse bone marrow

The bacteriophage ES2 is a virus for bacterial host cells. Unlike other phages that are known for their therapeutic effects, the ES2 phage has never been clearly examined as a therapeutic agent. To systematically and conclusively evaluate its therapeutic efficacy, the expression of the surface markers CD86, CD40, and MHCII, the production of the proinflammatory cytokines IL-6, IL-1α, IL-1β, and TNF-α, and the underlying NF-κB signaling pathway in murine bone marrow-derived dendritic cells (BM-DCs) in response to ES2 phage infection were examined. The bacteriophage ES2, which was isolated from swine fecal samples an antigen, affected the expression of the cell surface molecules and proinflammatory cytokines that are associated with the DC maturation processes. Treatment with ES2 phage also led to NF-κBp65 activation and translocation to the nucleus, which indicates the activation of NF-κB signaling. Furthermore, the ES2 phage induced the promoter activity of IL-12p40. Our chromatin immunoprecipitation assay revealed that p65 was enriched at the IL12-p40 promoter as a direct target of chromatin. The present study demonstrates that the ES2 phage potently induces DC maturation via immune-enhancement processes.

Doxorubicin induces atypical NF-κB activation through c-Abl kinase activity in breast cancer cells

PURPOSE

NF-κB transcription factor has been associated with cancer development and chemoresistance. We studied the signaling pathway activated by doxorubicin (DOX) leading to NF-κB activation in breast cancer cells.

METHODS

NF-κB activity was evaluated by electrophoretic mobility shift in T47D, ZR75.30 and primary culture (MBCDF) from a ductal infiltrating carcinoma. Cell viability was measured by crystal violet. Western blotting was performed to check the expression and phosphorylation of IκBα Ser-32/36. c-Abl was inhibited with Imatinib or by overexpressing a dominant negative form of c-Abl (K290R).

RESULTS

We found a correlation between sensitivity to DOX and amplitude of NF-κB activation. In cells least sensitive to DOX, NF-κB remained activated for longer time (T47D and MBCDF). The opposite effect was observed in cells sensitive to DOX (ZR75.30). DOX did not induce IκBα degradation or Ser-32/36 phosphorylation. Instead, there were modifications in the levels of IκBα tyrosine phosphorylation, suggesting an atypical NF-κB activation. In DOX-resistant cells, Imatinib treatment reduced IκBα tyrosine phosphorylation and NF-κB activity. The Imatinib-DOX combination significantly enhanced cell death of T47D and MBCDF breast cancer cells. Overexpression of c-Abl K290R in T47D and MBCDF cells reduced basal and DOX-induced NF-κB activation as well as IκBα tyrosine phosphorylation. In c-Abl K290R cells, DOX treatment did not mimic the combination Imatinib-DOX-induced cell death.

CONCLUSIONS

Inhibition of c-Abl inactivated IκBα/NF-κB pathway is associated with IκBα tyrosine phosphorylation in breast cancer cells. These results also raise the potential use of a combined therapy with Imatinib and DOX for breast cancer patients.

NSD1 mitigates caspase-1 activation by listeriolysin O in macrophages

Mammals and plants share pathogen-sensing systems named nod-like receptors (NLRs). Some NLRs form the inflammasome, a protein scaffold that regulates the secretion of interleukin (IL)-1β and IL-18 by cleaving catalytically inactive substrates into mature cytokines. Here, we show an immune conservation between plant and mammalian NLRs and demonstrate that the murine nuclear receptor binding SET domain protein 1 (NSD1), a protein that bears similarity to the NLR regulator enhanced downy mildew 2 (EDM2) in Arabidopsis, diminishes caspase-1 activity during extracellular stimulation with Listeria monocytogenes listeriolysin O (LLO). EDM2 is known to regulate plant developmental processes, whereas NSD1 is associated with developmental disorders. We observed that NSD1 neither affects nuclear factor (NF)-κB signaling nor regulates NLRP3 inflammasome gene expression at the chromatin, transcriptional or translational level during LLO stimulation of macrophages. Silencing of Nsd1 followed by LLO stimulation led to increased caspase-1 activation, enhanced post-translational maturation of IL-1β and IL-18 and elevated pyroptosis, a form of cell death associated with inflammation. Furthermore, treatment of macrophages with LLO^W492A, which lacks hemolytic activity due to a tryptophan to alanine substitution in the undecapeptide motif, indicates the importance of functional LLO for NSD1 regulation of the NLRP3 inflammasome. Taken together, our results indicate that NLR signaling in plants may be used for gene discovery in mammals.

Protein tyrosine phosphatase non-receptor type 22 modulates NOD2-induced cytokine release and autophagy

Background

Variations within the gene locus encoding protein tyrosine phosphatase non-receptor type 22 (PTPN22) are associated with the risk to develop inflammatory bowel disease (IBD). PTPN22 is involved in the regulation of T- and B-cell receptor signaling, but although it is highly expressed in innate immune cells, its function in other signaling pathways is less clear. Here, we study whether loss of PTPN22 controls muramyl-dipeptide (MDP)-induced signaling and effects in immune cells.

Material & Methods

Stable knockdown of PTPN22 was induced in THP-1 cells by shRNA transduction prior to stimulation with the NOD2 ligand MDP. Cells were analyzed for signaling protein activation and mRNA expression by Western blot and quantitative PCR; cytokine secretion was assessed by ELISA, autophagosome induction by Western blot and immunofluorescence staining. Bone marrow derived dendritic cells (BMDC) were obtained from PTPN22 knockout mice or wild-type animals.

Results

MDP-treatment induced PTPN22 expression and activity in human and mouse cells. Knockdown of PTPN22 enhanced MDP-induced activation of mitogen-activated protein kinase (MAPK)-isoforms p38 and c-Jun N-terminal kinase as well as canonical NF-κB signaling molecules in THP-1 cells and BMDC derived from PTPN22 knockout mice. Loss of PTPN22 enhanced mRNA levels and secretion of interleukin (IL)-6, IL-8 and TNF in THP-1 cells and PTPN22 knockout BMDC. Additionally, loss of PTPN22 resulted in increased, MDP-mediated autophagy in human and mouse cells.

Conclusions

Our data demonstrate that PTPN22 controls NOD2 signaling, and loss of PTPN22 renders monocytes more reactive towards bacterial products, what might explain the association of PTPN22 variants with IBD pathogenesis.

The roles of microRNAs on tuberculosis infection: meaning or myth?

The central proteins for protection against tuberculosis are attributed to interferon-γ, tumor necrosis factor-α, interleukin (IL)-6 and IL-1β, while IL-10 primarily suppresses anti-mycobacterial responses. Several studies found alteration of expression profile of genes involved in anti-mycobacterial responses in macrophages and natural killer (NK) cells from active and latent tuberculosis and from tuberculosis and healthy controls. This alteration of cellular composition might be regulated by microRNAs (miRNAs). Albeit only 1% of the genomic transcripts in mammalian cells encode miRNA, they are predicted to control the activity of more than 60% of all protein-coding genes and they have a huge influence in pathogenesis theory, diagnosis and treatment approach to some diseases. Several miRNAs have been found to regulate T cell differentiation and function and have critical role in regulating the innate function of macrophages, dendritic cells and NK cells. Here, we have reviewed the role of miRNAs implicated in tuberculosis infection, especially related to their new roles in the molecular pathology of tuberculosis immunology and as new targets for future tuberculosis diagnostics.

Immunomodulatory effect of chinese herbal medicine formula sheng-fei-yu-chuan-tang in lipopolysaccharide-induced acute lung injury mice

Traditional Chinese medicine formula Sheng-Fei-Yu-Chuan-Tang (SFYCT), consisting of 13 medicinal plants, was used to treat patients with lung diseases. This study investigated the immunoregulatory effect of SFYCT on intratracheal lipopolysaccharides- (LPS-) challenged acute lung injury (ALI) mice. SFYCT attenuated pulmonary edema, macrophages, and neutrophils infiltration in the airways. SFYCT decreased inflammatory cytokines, including tumor necrosis factor-α (TNFα), interleukin-1β, and interleukin-6 and inhibited nitric oxide (NO) production but increased anti-inflammatory cytokines, interleukin-4, and interleukin-10, in the bronchoalveolar lavage fluid of LPS-challenged mice. TNFα and monocyte chemotactic protein-1 mRNA expression in the lung of LPS-challenged mice as well as LPS-stimulated lung epithelial cell and macrophage were decreased by SFYCT treatment. SFYCT treatment also decreased the inducible nitric oxide synthase expression and phosphorylation of nuclear factor-κB (NF-κB) in the lung of mice and macrophage with LPS stimulation. SFYCT treatment dose dependently decreased the LPS-induced NO and reactive oxygen species generation in LPS-stimulated macrophage. In conclusion, SFYCT attenuated lung inflammation during LPS-induced ALI through decreasing inflammatory cytokines production while increasing anti-inflammatory cytokines production. The immunoregulatory effect of SFYCT is related to inhibiting NF-κB phosphorylation.

Genetic interaction between genes involved in NF-κB signaling pathway in systemic lupus erythematosus

Recently, multiple genetic associations have been found between genes involved in nuclear factor-kappaB (NF-κB) signaling pathway and systemic lupus erythematosus (SLE) or other autoimmune diseases. This study was undertaken to replicate some of these associations and further test for genetic interactions among these genes in SLE in a Chinese population. Ten single-nucleotide polymorphisms (SNPs) in NFKB1, REL, inhibitor of κB-like (IκBL), IκB kinase β (IKBKB), tumor necrosis factor receptor associated factor 6 (TRAF6), tumor necrosis factor a-induced protein 3 (TNFAIP3), TNFAIP3 interacting protein 1 (TNIP1) were genotyped in 898 Chinese patients with SLE and 988 healthy controls by Sequenom MassArray technology. Single-marker genetic association analysis was performed, and additive and multiplicative interactions were analyzed. Associations of TNFAIP3 rs2230926 (p=1.43 × 10(-3)) and TNIP1 rs10036748 (p=4.33 × 10(-3)) with SLE were replicated in our study. Two other SNPs, NFKB1 rs28362491 and IκBL rs2071592, showed nominal evidence for association (p=4.70 × 10(-2) and p=5.90 × 10(-3), respectively) but these were not significant after applying Bonferroni correction. Additive interaction analysis revealed significant interaction between NFKB1 rs28362491 and TNFAIP3 rs2230926 (RERI=0.98, 95%CI=0.02-1.93; AP=43.2%, 95%CI=0.12-0.74). Significant multiplicative interaction was observed between NFKB1 rs28362491 and TNIP1 rs3792783 (p=0.03). Our results provide evidence for gene-gene interactions, which further support the important role of NF-κB signaling pathway in the genetic basis of SLE and the notion of genetic interactions accounting for missing heritability.

Rotenone could activate microglia through NFκB associated pathway

Parkinson's disease (PD) is a common neurodegenerative disease, and its etiology remains obscure. Increasing evidence has suggested an important role for environmental factors such as exposure to pesticides in increasing the risk of developing PD and inflammation is the early incident during the process of PD. In this study, we measure the pro-inflammatory cytokines by enzyme-linked immunosorbnent assay and RT-PCR methods; analyze the reactive oxygen species by DCFH-DA; detected nuclear factor κB (NFκB) translocation by western blot and immunofluorescence methods; and analyze the phosphorylation of mitogen-activated protein (MAP) kinase and protein level of Nurr1 by western blot. Results showed that rotenone could induce tumor neurosis factor α (TNFα) and interleukin 1β (IL-1β) release from BV-2 cells, enhance TNFα and IL-1β mRNA levels in substantia nigra lesioned by rotenone; also, rotenone could increase the phosphorylation of inhibitor of κB (IκB), extracellular regulated protein kinase , c-Jun N-terminal kinase, p38 MAP kinases and promote p65 subunit of NFκB translocation to nuclear; at the same time, rotenone could decrease the protein level of Nurr1 in nuclear. So, rotenone exerted toxicity through activating microglia, and its mechanism might be associated with NFκB signal pathway.

Pellino3 ubiquitinates RIP2 and mediates Nod2-induced signaling and protective effects in colitis

Mutations that result in loss of function of Nod2, an intracellular receptor for bacterial peptidoglycan, are associated with Crohn's disease. Here we found that the E3 ubiquitin ligase Pellino3 was an important mediator in the Nod2 signaling pathway. Pellino3-deficient mice had less induction of cytokines after engagement of Nod2 and had exacerbated disease in various experimental models of colitis. Furthermore, expression of Pellino3 was lower in the colons of patients with Crohn's disease. Pellino3 directly bound to the kinase RIP2 and catalyzed its ubiquitination. Loss of Pellino3 led to attenuation of Nod2-induced ubiquitination of RIP2 and less activation of the transcription factor NF-κB and mitogen-activated protein kinases (MAPKs). Our findings identify RIP2 as a substrate for Pellino3 and Pellino3 as an important mediator in the Nod2 pathway and regulator of intestinal inflammation.

Pancreatic acinar cell nuclear factor κB activation because of bile acid exposure is dependent on calcineurin

Biliary pancreatitis is the most common etiology of acute pancreatitis, accounting for 30-60% of cases. A dominant theory for the development of biliary pancreatitis is the reflux of bile into the pancreatic duct and subsequent exposure to pancreatic acinar cells. Bile acids are known to induce aberrant Ca(2+) signals in acinar cells as well as nuclear translocation of NF-κB. In this study, we examined the role of the downstream Ca(2+) target calcineurin on NF-κB translocation. Freshly isolated mouse acinar cells were infected for 24 h with an adenovirus expressing an NF-κB luciferase reporter. The bile acid taurolithocholic acid-3-sulfate caused NF-κB activation at concentrations (500 μm) that were associated with cell injury. We show that the NF-κB inhibitor Bay 11-7082 (1 μm) blocked translocation and injury. Pretreatment with the Ca(2+) chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, the calcineurin inhibitors FK506 and cyclosporine A, or use of acinar cells from calcineurin Aβ-deficient mice each led to reduced NF-κB activation with taurolithocholic acid-3-sulfate. Importantly, these manipulations did not affect LPS-induced NF-κB activation. A critical upstream regulator of NF-κB activation is protein kinase C, which translocates to the membranes of various organelles in the active state. We demonstrate that pharmacologic and genetic inhibition of calcineurin blocks translocation of the PKC-δ isoform. In summary, bile-induced NF-κB activation and acinar cell injury are mediated by calcineurin, and a mechanism for this important early inflammatory response appears to be upstream at the level of PKC translocation.

Inhibiting neuropeptide Y Y1 receptor modulates melanocortin receptor- and NF-κB-mediated feeding behavior in phenylpropanolamine-treated rats

Neuropeptide Y (NPY) and nuclear factor-kappa B (NF-κB) are involved in regulating anorexia elicited by phenylpropanolamine (PPA), a sympathomimetic drug. This study explored whether NPY Y1 receptor (Y1R) is involved in this process, and a potential role for the proopiomelanocortin system was identified. Rats were given PPA once a day for 4days. Changes in the hypothalamic expression of the NPY, Y1R, NF-κB, and melanocortin receptor 4 (MC4R) levels were assessed and compared. The results indicated that food intake and NPY expression decreased, with the largest reductions observed on Day 2 (approximately 50% and 45%, respectively), whereas NF-κB, MC4R, and Y1R increased, achieving maximums on Day 2 (160%, 200%, and 280%, respectively). To determine the role of Y1R, rats were pretreated with Y1R antisense or a Y1R antagonist via intracerebroventricular injection 1h before the daily PPA dose. Y1R knockdown and inhibition reduced PPA anorexia and partially restored the normal expression of NPY, MC4R, and NF-κB. The data suggest that hypothalamic Y1R participates in the appetite-suppression from PPA by regulating MC4R and NF-κB. The results of this study increase our understanding of the molecular mechanisms in PPA-induced anorexia.

Inhibition of IκB kinase reduces the multiple organ dysfunction caused by sepsis in the mouse

Nuclear factor κB (NF-κB) plays a pivotal role in sepsis. Activation of NF-κB is initiated by the signal-induced ubiquitylation and subsequent degradation of inhibitors of kappa B (IκBs) primarily via activation of the IκB kinase (IKK). This study was designed to investigate the effects of IKK inhibition on sepsis-associated multiple organ dysfunction and/or injury (MOD) and to elucidate underlying signaling mechanisms in two different in vivo models: male C57BL/6 mice were subjected to either bacterial cell wall components [lipopolysaccharide and peptidoglycan (LPS/PepG)] or underwent cecal ligation and puncture (CLP) to induce sepsis-associated MOD. At 1 hour after LPS/PepG or CLP, mice were treated with the IKK inhibitor IKK 16 (1 mg/kg body weight). At 24 hours, parameters of organ dysfunction and/or injury were assessed in both models. Mice developed a significant impairment in systolic contractility (echocardiography), and significant increases in serum creatinine, serum alanine aminotransferase and lung myeloperoxidase activity, thus indicating cardiac dysfunction, renal dysfunction, hepatocellular injury and lung inflammation, respectively. Treatment with IKK 16 attenuated the impairment in systolic contractility, renal dysfunction, hepatocellular injury and lung inflammation in LPS/PepG-induced MOD and in polymicrobial sepsis. Compared with mice that were injected with LPS/PepG or underwent CLP, immunoblot analyses of heart and liver tissues from mice that were injected with LPS/PepG or underwent CLP and were also treated with IKK 16 revealed: (1) significant attenuation of the increased phosphorylation of IκBα; (2) significant attenuation of the increased nuclear translocation of the NF-κB subunit p65; (3) significant attenuation of the increase in inducible nitric oxide synthase (iNOS) expression; and (4) a significant increase in the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS). Here, we report for the first time that delayed IKK inhibition reduces MOD in experimental sepsis. We suggest that this protective effect is (at least in part) attributable to inhibition of inflammation through NF-κB, the subsequent decrease in iNOS expression and the activation of the Akt-eNOS survival pathway.

Redox regulation of T-cell function: from molecular mechanisms to significance in human health and disease

Reactive oxygen species (ROS) are thought to have effects on T-cell function and proliferation. Low concentrations of ROS in T cells are a prerequisite for cell survival, and increased ROS accumulation can lead to apoptosis/necrosis. The cellular redox state of a T cell can also affect T-cell receptor signaling, skewing the immune response. Various T-cell subsets have different redox statuses, and this differential ROS susceptibility could modulate the outcome of an immune response in various disease states. Recent advances in T-cell redox signaling reveal that ROS modulate signaling cascades such as the mitogen-activated protein kinase, phosphoinositide 3-kinase (PI3K)/AKT, and JAK/STAT pathways. Also, tumor microenvironments, chronic T-cell stimulation leading to replicative senescence, gender, and age affect T-cell susceptibility to ROS, thereby contributing to diverse immune outcomes. Antioxidants such as glutathione, thioredoxin, superoxide dismutase, and catalase balance cellular oxidative stress. T-cell redox states are also regulated by expression of various vitamins and dietary compounds. Changes in T-cell redox regulation may affect the pathogenesis of various human diseases. Many strategies to control oxidative stress have been employed for various diseases, including the use of active antioxidants from dietary products and pharmacologic or genetic engineering of antioxidant genes in T cells. Here, we discuss the existence of a complex web of molecules/factors that exogenously or endogenously affect oxidants, and we relate these molecules to potential therapeutics.

Polysaccharide from Ganoderma atrum evokes antitumor activity via Toll-like receptor 4-mediated NF-κB and mitogen-activated protein kinase signaling pathways

Ganoderma atrum has been used as a traditional Chinese medicine for centuries. In this study, the antitumor activity of a novel G. atrum polysaccharide (PSG-1) was investigated in vitro and in vivo using S180 tumor-bearing mice. The results showed that PSG-1 significantly inhibited the proliferation of S180 via the activation of macrophages in a dose-dependent manner. PSG-1-primed macrophages exhibited a higher tumoricidal activity than untreated macrophages. Administration of PSG-1 significantly inhibited the growth of transplantable sarcoma S180-bearing mice and increased macrophage phagocytosis and the levels of cytokines and nitride oxide. Expression of Toll-like receptor (TLR) 4 in the membrane was markedly increased in PSG-1-treated groups, suggesting that it may be a possible receptor for PSG-1. PSG-1 also promoted the translocation of the p65 subunit of NF-κB from cytosol to nucleus and the degradation of IκBα. Moreover, the phosphorylation of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1/2, and c-Jun N-terminal kinase in macrophages was improved by PSG-1 in a dose-dependent manner. Therefore, it is suggested that PSG-1 may elicit its antitumor effect by improving immune system functions through TLR4-mediated NF-κB and MAPK signaling pathways.

Local injection of dsRNA targeting calcitonin receptor-like receptor (CLR) ameliorates Clostridium difficile toxin A-induced ileitis

Enteritis caused by Clostridium difficile toxin (Tx) is a nosocomial disease of increasing clinical concern, but the local mediators of C. difficile TxA inflammation are unknown. The potent vasodilator calcitonin gene-related peptide mediates neurogenic inflammation via the calcitonin receptor-like receptor (CLR). Here we examined the ileum-specific effects of reducing CLR on TxA ileitis by local preinjection of double-stranded RNAs. Treatment with CLR dsRNA for 7 d decreased CLR immunoreactivity, whereas treatment with non-CLR dsRNA did not. Subsequent injection of TxA in the same location increased CLR in rats treated with non-CLR dsRNA but not in rats treated with CLR dsRNA, documenting that local injection of dsRNA is effective in preventing the increase in CLR immunoreactivity in response to local TxA. After non-CLR dsRNA pretreatment, TxA induced robust intestinal secretion, myeloperoxidase activity, and histopathologic indications of inflammation including epithelial damage, congestion, neutrophil infiltration, loss of mucin from goblet cells, and increase in mast cell numbers. After CLR dsRNA pretreatment, TxA-induced changes in intestinal secretion and histopathologic inflammation were improved, including normal mucin staining and fewer resident mast cells. Loss of CLR prevented TxA-mediated activation of NF-κB and concomitant increases in pERK1/2 and TNF-α mRNA. Locally produced CLR plays a proinflammatory role in TxA ileitis via MAPK signaling and TNF-α. The results reported here strongly suggest that a local injection of dsRNA targeting CLR could be an effective local therapeutic approach at the inflammation site in the treatment of a growing, clinically relevant hospital-acquired disease, C. difficile infection.

Microarray-assisted pathway analysis identifies MT1X & NFκB as mediators of TCRP1-associated resistance to cisplatin in oral squamous cell carcinoma

We recently reported that TCRP1, a novel multidrug-resistance associated human gene, can mediate cisplatin resistance in OSCC cells. However, the molecular mechanism underlying this role of TCRP1 remained to be elucidated. In this study, by using Human Toxicology and Drug Resistance Microarray, we identified 30 genes with significantly different expression levels between Tca/PYM and TCRP1 knockdown cell lines. Co-immunoprecipitation experiments and GST-pull down assays showed that metallothionein1X (MT1X) and Akt interact with TCRP1. siRNA-mediated knockdown of TCRP1 and MT1X was found to sensitize cells to cisplatin, leading to increased apoptosis and inhibition of cell proliferation. These functions of TCRP1 may be caused at least in part via activation of the PI3K/Akt/NF-κB signaling pathway. Taken together, our findings indicate that TCRP1 may be an important drug target for improvement of the treatment and survival of patients with oral squamous cell carcinoma.

Yuwen02f1 suppresses LPS-induced endotoxemia and adjuvant-induced arthritis primarily through blockade of ROS formation, NFkB and MAPK activation

Phagocytes release inflammatory mediators to defense harmful stimuli upon bacterial invasion, however, excessive inflammatory reaction leads to tissue damage and manifestation of pathological states. Therefore, targeting on uncontrolled inflammation seems feasible to control numerous inflammation-associated diseases. Under the drug screening process of synthetic diphenylpyrazole derivatives, we discovered compound yuwen02f1 possesses anti-inflammatory effects in decreasing the release of pro-inflammatory cytokines including TNFα and IL-6, nitric oxide, reactive oxygen species (ROS) as well as inhibiting migration of LPS-stimulated phagocytes. In addition, we observed that the molecular mechanism of yuwen02f1-mediated anti-inflammation is associated with decreasing phosphorylation of MAPK molecules including ERK1/2, JNK and p38, and attenuating translocation of p47(phox) and p67(phox) to the cell membrane. Yuwen02f1 also reverses IκBα degradation and attenuates the expression of NFκB-related downstream inducible enzymes like iNOS and COX-2. Furthermore, we found that yuwen02f1 attenuates some pathological syndromes of LPS-induced sepsis and adjuvant-induced arthritis in mice, as evidenced by decreasing the cytokine production, reversing thrombocytopenic syndrome, protecting the mice from tissue injury in septic mice, and attenuating paw edema in arthritic mice as well. These results suggest that yuwen02f1 is a potential anti-inflammatory agent for alleviating syndromes of acute and chronic inflammatory diseases as evidenced by attenuating the generation of cytokines and down-regulating the expression of iNOS and COX-2 through the blockade of ROS generation and NADPH oxidase, NFκB and MAPK activation pathways in LPS-stimulated phagocytes.

Pellino3 targets the IRF7 pathway and facilitates autoregulation of TLR3- and viral-induced expression of type I interferons

Toll-like receptors (TLRs) sense pathogen-associated molecules and respond by inducing cytokines and type I interferon. Here we show that genetic ablation of the E3 ubiquitin ligase Pellino3 augmented the expression of type I interferon but not of proinflammatory cytokines in response to TLR3 activation. Pellino3-deficient mice had greater resistance against the pathogenic and lethal effects of encephalomyocarditis virus (EMCV). TLR3 signaling induced Pellino3, which in turn interacted with and ubiquitinated TRAF6. This modification suppressed the ability of TRAF6 to interact with and activate IRF7, resulting in downregulation of type I interferon expression. Our findings highlight a new physiological role for Pellino3 and define a new autoregulatory network for controlling type I interferon expression.

Antimicrobial peptide LL37 promotes vascular endothelial growth factor-A expression in human periodontal ligament cells

BACKGROUND AND OBJECTIVE

LL37, originally found in the innate immune system, is a robust antimicrobial peptide. LL37 exhibits multiple bio-functions in various cell types, such as migration, cytokine production, apoptosis, and angiogenesis besides its antimicrobial activity Periodontal ligament (PL) cells play a pivotal role in periodontal tissue regeneration. Based on these findings, we hypothesized that LL37 can regulate PL cell function to promote regeneration of periodontal tissue. To prove this hypothesis, we investigated the effect of LL37 on the potent angiogenic inducer vascular endothelial growth factor (VEGF) expression in cultures of human PL (HPL) cells because neovascularization is indispensable for the progress of tissue regeneration. Moreover, we investigated the signaling cascade associated with LL37-induced VEGF expression.

MATERIAL AND METHOD

HPL cells were treated with synthesized LL37 in the presence or absence of PD98059, a MEK-ERK inhibitor, or PDTC, an NF-κB inhibitor. VEGF expression levels were assessed by real-time polymerase chain reaction analysis and an enzyme-linked immunoassay. Phosphorylation levels of ERK1/2 or NF-κB p65 were determined by Western blotting.

RESULTS

LL37 upregulated VEGF-A expression at the mRNA and protein levels in HPL cells, while VEGF-B mRNA expression was not affected. Both ERK and NF-κB inhibitors clearly abrogated the increase in VEGF-A levels induced by LL37 in HPL cells. Importantly, LL37 increased phosphorylated levels of ERK1/2 and NF-κB p65 in HPL cells.

CONCLUSION

LL37 induces VEGF-A production in HPL cells via ERK and NF-κB signaling cascades, which may result in angiogenesis, thereby contributing to periodontal regeneration.

Anti-inflammatory effect of fucoxanthin derivatives isolated from Sargassum siliquastrum in lipopolysaccharide-stimulated RAW 264.7 macrophage

In this study, the anti-inflammatory effect of fucoxanthin (FX) derivatives, which was isolated from Sargassum siliquastrum were evaluated by examining their inhibitory effects on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells. The FX derivatives were isolated from activity-guided chloroform fraction using inhibition of nitric oxide (NO) production and identified as 9'-cis-(6'R) fucoxnathin (FXA), and 13-cis and 13'-cis-(6'R) fucoxanthin complex (FXB) on the basis of a comparison of NMR spectroscopic data. Both FXA and FXB significantly inhibited the NO production and showed slightly reduce the PGE2 production. However, FXB exhibited cytotoxicity at the whole tested concentration, therefore, the results of FXA was only illustrate for further experiments. FXA induced dose-dependent reduction in the inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) proteins as well as mRNA expression. In addition, FXA reduced the LPS-stimulated production and mRNA expressions of TNF-α and IL-6 in a dose-dependent manner whereas IL-1β production do not inhibit by addition of FXA. Taken together, these findings indicate that the anti-inflammatory properties of FXA may be due to the inhibition of iNOS/NO pathway which associated with the attenuation of TNF-α and IL-6 formation. Thus FXA may provide a potential therapeutic approach for inflammation related diseases.

Altered microRNA signatures in sputum of patients with active pulmonary tuberculosis

Role of microRNA (miRNA) has been highlighted in pathogen-host interactions recently. At present, their role in active pulmonary tuberculosis is unknown. The aim of the study was to delineate miRNA expression in sputum supernatant of patients with active pulmonary tuberculosis. Expression of miRNAs was evaluated by microarray analysis and differentially expressed miRNAs were validated by RT-qPCR. Secreted cytokines TNF-α and IL-6 were measured by ELISA. We found that 95 miRNAs were differentially expressed between tuberculosis group and controls. More miRNAs (52 out of 95 miRNAs) were underexpressed than overexpressed during tuberculosis infection. Overexpression of miR-3179, miR-147 and underexpression of miR-19b-2* in TB group compared with controls were confirmed in the validation cohort. TNF-α and IL-6 levels were not significantly altered between TB group and controls. For the first time, differential expression of miRNAs in sputum was found in active pulmonary tuberculosis. The study provides rationale for identifying the role of miRNAs in the pathogenesis of pulmonary tuberculosis and indicates potential for miRNA-based therapeutic strategies.

Nuclear factor κB and cyclooxygenase-2 immunoexpression in oral dysplasia and oral squamous cell carcinoma

Oral leukoplakia is the main potentially malignant oral lesion, and oral squamous cell carcinoma accounts for more than 95% of all malignant neoplasms in the oral cavity. Therefore, the aim of this study was to verify the immunoexpression of nuclear factor κB (NF-κB) and cyclooxygenase-2 (COX-2) proteins in dysplastic oral lesions and oral squamous cell carcinoma. Immunohistochemical reactions were performed on 6 inflammatory fibrous hyperplasia, 28 oral leukoplakia, and 15 oral squamous cell carcinoma paraffin-embedded samples. Immunoperoxidase reaction for NF-κB and COX-2 was applied on the specimens, and the positivity of the reactions was calculated for 1000 epithelial cells. Using the analysis of variance and the Tukey post hoc statistical analyses, a significantly increased immunoexpression for NF-κB was observed when oral squamous cell carcinoma samples were compared with the other groups studied. However, using the Kruskal-Wallis and the Dunn post hoc tests, a statistically significant result for COX-2 expression was obtained only when the moderate dysplasia group was compared with the inflammatory fibrous hyperplasia group. Nuclear factor κB may participate in the malignant phenotype acquisition process of the oral squamous cell carcinoma in its late stages, whereas COX-2 may be involved in the early stages of oral carcinogenesis process.

Monocyte chemotactic protein-1-induced protein-1 (MCPIP1) is a novel multifunctional modulator of inflammatory reactions

The generalized inflammatory response leads to activation of hundreds of genes transcribed in an established sequence in specialized cells. Transcriptome analysis of human monocyte-derived cells stimulated with IL-1beta or with monocyte chemotactic protein-1 (MCP-1) has led to the identification of a new inflammation-related gene ZC3H12A encoding a chain of 599 amino acids corresponding to a 66-kDa protein. The protein, given a provisional name of MCPIP1 (monocyte chemotactic protein-induced protein-1), is expressed in several human and murine tissues such as bone marrow, spleen, heart and placenta. In in vivo studies, mice with inactivated MCPIP1-encoding gene showed growth retardation, lymphadenopathy, splenomegaly and enhanced inflammatory symptoms. Principal molecular features of MCPIP1 include a single zinc finger motif, an RNase-like PIN domain and ubiquitin-binding domain. Reports from independent laboratories suggest that MCPIP1 may function also as a deubiquitinase. Although MCPIP1 is regarded by some authors as a new transcription factor or cell differentiation factor modulating angiogenesis or adipogenesis, its principal function appears to be downregulation of inflammatory responses through at least two independent mechanisms: increased degradation of cytokine mRNAs and inhibition of LPS- and IL-1-induced NF-kappaB signaling pathway. The interference with NF-kappaB activation is highly complex and includes TRAF6 and TANK interaction with the ubiquitin-associated (UBA) domain of MCPIP1. Purified MCPIP1 protein was reported to degrade specific mRNA and cleave K48- and K63-linked polyubiquitin chains. Although some structural features and the mechanism of action of MCPIP1 are not fully explained yet, its importance in the regulation of inflammatory reactions has been firmly established.

Chlorophyll revisited: anti-inflammatory activities of chlorophyll a and inhibition of expression of TNF-α gene by the same

In view of the folklore use of green leaves to treat inflammation, the anti-inflammatory property of chlorophylls and their degradation products were studied. Chlorophyll a and pheophytin a (magnesium-free chlorophyll a) from fresh leaves showed potent anti-inflammatory activity against carrageenan-induced paw edema in mice and formalin-induced paw edema in rats. Chlorophyll a inhibited bacterial lipopolysaccharide-induced TNF-α (a pro-inflammatory cytokine) gene expression in HEK293 cells, but it did not influence the expression of inducible nitric acid synthase and cyclooxygenase-2 genes. Chlorophyll b only marginally inhibited both inflammation and TNF-α gene expression. But both chlorophyll a and chlorophyll b showed the same level of marginal inhibition on 12-O-tetradecanoyl-phorbol-13-acetate-induced NF-κB activation. Chlorophylls and pheophytins showed in vitro anti-oxidant activity. The study shows that chlorophyll a and its degradation products are valuable and abundantly available anti-inflammatory agents and promising for the development of phytomedicine or conventional medicine to treat inflammation and related diseases.

Echinocystic acid ameliorates lung inflammation in mice and alveolar macrophages by inhibiting the binding of LPS to TLR4 in NF-κB and MAPK pathways

Orally administered lancemaside A, which is isolated from Codonopsis lanceolata (family Campanulaceae), showed anti-colitic effect in mice. However, its metabolite echinocystic acid was absorbed into the blood. Therefore, its anti-inflammatory effects were investigated in lipopolysaccharide (LPS)-stimulated alveolar macrophages in vitro and acute lung injury in vivo. Alveolar macrophages from mice were stimulated with LPS and were treated with echinocystic acid. Acute lung injury was induced by intratracheal administration of LPS in mice. Mice were treated with echinocystic acid or dexamethasone. Echinocystic acid potently suppressed the production of the pro-inflammatory cytokines, TNF-α and IL-1β, as well as of the activations of NF-κB and MAPKS, in LPS-stimulated alveolar macrophages. Echinocystic acid also down-regulated the production of inflammatory markers, which included inducible nitric oxide synthase and cyclooxygenase-2, as well as the inflammatory mediators, nitric oxide and prostaglandin E(2), in LPS-stimulated alveolar macrophages. Echinocystic acid also inhibited the activation of IL-1 receptor-associated kinases, and the activation of mitogen-activated protein kinases in LPS-stimulated alveolar macrophages. Furthermore, echinocystic acid potently inhibited the interaction between LPS and TLR4 in alveolar macrophages transfected with or without MyD88 siRNA, although it did not inhibit the binding in the macrophages transfected with TLR4 siRNA. Echinocystic acid suppressed LPS-induced acute lung inflammation in mice, as well as the expression of pro-inflammatory cytokines, such as IL-1β and TNF-α, and their transcription factor, NF-κB. On the basis of these findings, echinocystic acid, a metabolite of lancemaside A, may express anti-inflammatory effects by inhibiting the binding of LPS to TLR4 on macrophages.

Dysregulated TLR3-dependent signaling and innate immune activation in superoxide-deficient macrophages from nonobese diabetic mice

In type 1 diabetes (T1D), reactive oxygen species (ROS) and proinflammatory cytokines produced by macrophages and other innate immune cells destroy pancreatic β cells while promoting autoreactive T cell maturation. Superoxide-deficient nonobese diabetic mice (NOD.Ncf1(m1J)) are resistant to spontaneous diabetes, revealing the integral role of ROS signaling in T1D. Here, we evaluate the innate immune activation state of bone marrow-derived macrophages (BM-Mϕ) from NOD and NOD.Ncf1(m1J) mice after poly(I:C)-induced Toll-like receptor 3 (TLR3) signaling. We show that ROS synthesis is required for efficient activation of the NF-κB signaling pathway and concomitant expression of TLR3 and the cognate adaptor molecule, TRIF. Poly(I:C)-stimulated NOD.Ncf1(m1J) BM-Mϕ exhibited a 2- and 10-fold decrease in TNF-α and IFN-β proinflammatory cytokine synthesis, respectively, in contrast to NOD BM-Mϕ. Optimal expression of IFN-α/β is not solely dependent on superoxide synthesis, but requires p47(phox) to function in a NOX-independent manner to mediate type I interferon synthesis. Interestingly, MHC-II I-A(g7) expression necessary for CD4 T cell activation is increased 2-fold relative to NOD, implicating a role for superoxide in I-A(g7) downregulation. These findings suggest that defective innate immune-pattern-recognition receptor activation and subsequent decrease in TNF-α and IFN-β proinflammatory cytokine synthesis necessary for autoreactive T cell maturation may contribute to the T1D protection observed in NOD.Ncf1(m1J) mice.

The effect of the NF-kappa B inhibitors curcumin and lactacystin on myogenic differentiation of rhabdomyosarcoma cells

Rhabdomyosarcoma is a soft tissue sarcoma mainly seen in children. Despite considerable progress within the last few years, therapeutic approaches for this type of tumor are still limited. The respective tumor cells originate from myogenic precursor cells and are characterized by a blockade in their differentiation program. Interestingly, there is a direct inverse correlation between the differentiation status of a specific rhabdomyosarcoma cell and its metastatic potential. Thus, here, we tested whether the ubiquitous transcription factor NF-κB, which regulates myogenic differentiation and is also a promising therapeutic target in the treatment of other types of tumors, might be an interesting candidate for the development of novel rhabdomyosarcoma treatment strategies. For this purpose, we analyzed NF-κB activity (classical pathway) in myoblasts with different differentiation potential, specifically in three different rhabdomyosarcoma cell lines. In addition, we inhibited NF-κB activity in these cells and analyzed the effects on myogenic differentiation. We show that after the induction of differentiation, NF-κB activity declines rapidly in normal myoblasts, but only slightly in rhabdomyosarcoma cells. However, after treatment of the cells with two different small-molecule NF-κB-inhibiting compounds, the IKK inhibitor curcumin and the proteasome inhibitor lactacystin, we found that neither curcumin nor lactacystin promoted myogenic differentiation in either normal myoblasts or rhabdomyosarcoma cells. Taken together, our data suggest that treatment with curcumin or lactacystin might not be a suitable approach in the treatment of rhabdomyosarcoma.

NF-κB p65 phosphorylated at serine-536 is an independent prognostic factor in Swedish colorectal cancer patients

INTRODUCTION

The NF-κB transcription factor protein family has diverse cellular and biological functions, and posttranslational modification is important to regulate these functions. An important site of phosphorylation of NF-κB p65 subunit is at serine-536 (phospho-Ser536-p65), and this phosphorylation is involved in regulation of transcriptional activity, nuclear localization, and protein stability.

PATIENTS AND METHODS

In this study, we investigated expression of phospho-Ser536-p65 in colorectal cancers and its relationships with clinicopathological factors. The expression of phospho-Ser536-p65 was examined by immunohistochemistry in 203 primary colorectal cancers, 156 normal mucosa specimens, and 18 metastases in the lymph nodes.

RESULTS

The expression of phospho-Ser536-p65 increased from normal mucosa to primary tumor (p < 0.0001). Further, the increased expression of phospho-Ser536-p65 in the cytoplasm of the primary tumors correlated with worse survival of the patients independently of gender, age, tumor location, stage, and differentiation (p = 0.04; hazard ratio, 1.89; 95% CI 1.03-3.47).

CONCLUSION

The NF-κB p65 subunit phosphorylated at serine-536 is an independent prognostic factor in colorectal cancer patients.

Anti-inflammatory effects of ladostigil and its metabolites in aged rat brain and in microglial cells

Impaired mitochondrial function accompanied by microglial activation and the release of nitric oxide (NO) and pro-inflammatory cytokines has been reported in Alzheimer's disease, its prodromal phase of Mild Cognitive Impairment (MCI) and in aged rats. The present study showed that 6 months treatment of 16 month old rats with ladostigil (1 mg/kg/day), a novel drug designed for the treatment of MCI, prevented the development of spatial memory deficits at 22 months of age and significantly decreased the gene expression of IL-1β, IL-6, TNF-α and inducible nitric oxide synthase (iNOS) in the parietal cortex. It was also shown that concentrations ranging from 1nM-1 μM of ladostigil and three of its active metabolites inhibited the release of nitric oxide (NO) induced by lipopolysaccharide (LPS) from mouse microglial cells by up to 35-40 %. Ladostigil and its metabolites (10nM) also reduced TNF-α mRNA and protein by 25-35 % and IL-1β and inducible nitric oxide synthase (iNOS) mRNA by 20-35 %. The concentration of 10nM is in the range of that of the parent drug, R-MCPAI and R-HPAI found in plasma after oral administration of ladostigil (1 mg/kg/day) to rats. All the compounds inhibited the degradation of IkB-α and nuclear translocation of the p65 subunit of NF-kB. They also inhibited phosphorylation of p38 and ERK1/2 mitogen-activated protein kinase (MAPK), but had no effect on that of JNK. We propose that the anti-inflammatory activity may contribute towards the neuroprotective action of ladostigil against the development of memory impairments induced by aging or toxin-induced microglial activation.

Mutations in RIPK4 cause the autosomal-recessive form of popliteal pterygium syndrome

The autosomal-recessive form of popliteal pterygium syndrome, also known as Bartsocas-Papas syndrome, is a rare, but frequently lethal disorder characterized by marked popliteal pterygium associated with multiple congenital malformations. Using Affymetrix 250K SNP array genotyping and homozygosity mapping, we mapped this malformation syndrome to chromosomal region 21q22.3. Direct sequencing of RIPK4 (receptor-interacting serine/threonine kinase protein 4) showed a homozygous transversion (c.362T>A) that causes substitution of a conserved isoleucine with asparagine at amino acid position 121 (p.Ile121Asn) in the serine/threonine kinase domain of the protein. Additional pathogenic mutations-a homozygous transition (c.551C>T) that leads to a missense substitution (p.Thr184Ile) at a conserved position and a homozygous one base-pair insertion mutation (c.777_778insA) predicted to lead to a premature stop codon (p.Arg260ThrfsX14) within the kinase domain-were observed in two families. Molecular modeling of the kinase domain showed that both the Ile121 and Thr184 positions are critical for the protein's stability and kinase activity. Luciferase reporter assays also demonstrated that these mutations are critical for the catalytic activity of RIPK4. RIPK4 mediates activation of the nuclear factor-κB (NF-κB) signaling pathway and is required for keratinocyte differentiation and craniofacial and limb development. The phenotype of Ripk4(-/-) mice is consistent with the human phenotype presented herein. Additionally, the spectrum of malformations observed in the presented families is similar, but less severe than the conserved helix-loop-helix ubiquitous kinase (CHUK)-deficient human fetus phenotype; known as Cocoon syndrome; this similarity indicates that RIPK4 and CHUK might function via closely related pathways to promote keratinocyte differentiation and epithelial growth.

Soyasaponin Ab ameliorates colitis by inhibiting the binding of lipopolysaccharide (LPS) to Toll-like receptor (TLR)4 on macrophages

Many clinical studies have shown that daily intake of soybean [ Glycine max (L.) Merr., Fabacease] or its foods may reduce the risk of osteoporosis, heart attack, hyperlipidemia, coronary heart disease, cardiovascular and chronic renal diseases, and cancers, including prostate, colon, and breast cancers. Of the soy constituents, soyasaponins exhibit anti-aging, antioxidant, apoptotic, and anti-inflammatory effects. However, the anti-inflammatory effect of soyasaponin Ab has not been thoroughly studied. Therefore, we investigated its anti-inflammatory effects in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitic mice and lipopolysaccharide (LPS)-stimulated peritoneal macrophages. Soyasaponin Ab inhibited colon shortening, myeloperoxidase activity, the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), and activation of the transcription factor nuclear factor-κB (NF-κB). Soyasaponin Ab (1, 2, 5, and 10 μM) inhibited the production of NO (IC(50) = 1.6 ± 0.1 μM) and prostaglandin E(2) (IC(50) = 2.0 ± 0.1 ng/mL), the expression of tumor necrosis factor (TNF)-α (IC(50) = 1.3 ± 0.1 ng/mL), interleukin (IL)-1β (IC(50) = 1.5 ± 0.1 pg/mL), and toll-like receptor (TLR)4, and the phosphorylation of interleukin-1 receptor-associated kinase (IRAK)-1 in LPS-stimulated peritoneal macrophages. Soyasaponin Ab weakly inhibited the phosphorylation of ERK, JNK, and p38. Soyasaponin Ab significantly reduced the binding of Alexa-Fluor-594-conjugated LPS to peritoneal macrophages. Soyasaponin Ab did not affect TLR4 expression or LPS-induced NF-κB activation in TLR4 siRNA-treated peritoneal macrophages (knockdown efficiency of TLR4 > 94%). On the basis of these findings, soyasaponin Ab may ameliorate colitis by inhibiting the binding of LPS to TLR4 on macrophages.