The NF-kappaB pathway

Binding of nuclear factor κB to noncanonical consensus sites reveals its multimodal role during the early inflammatory response

Mammalian cells have developed intricate mechanisms to interpret, integrate, and respond to extracellular stimuli. For example, tumor necrosis factor (TNF) rapidly activates proinflammatory genes, but our understanding of how this occurs against the ongoing transcriptional program of the cell is far from complete. Here, we monitor the early phase of this cascade at high spatiotemporal resolution in TNF-stimulated human endothelial cells. NF-κB, the transcription factor complex driving the response, interferes with the regulatory machinery by binding active enhancers already in interaction with gene promoters. Notably, >50% of these enhancers do not encode canonical NF-κB binding motifs. Using a combination of genomics tools, we find that binding site selection plays a key role in NF-κΒ–mediated transcriptional activation and repression. We demonstrate the latter by describing the synergy between NF-κΒ and the corepressor JDP2. Finally, detailed analysis of a 2.8-Mbp locus using sub-kbp-resolution targeted chromatin conformation capture and genome editing uncovers how NF-κΒ that has just entered the nucleus exploits pre-existing chromatin looping to exert its multimodal role. This work highlights the involvement of topology in cis-regulatory element function during acute transcriptional responses, where primary DNA sequence and its higher-order structure constitute a regulatory context leading to either gene activation or repression.

Anti-inflammatory properties of tianeptine on lipopolysaccharide-induced changes in microglial cells involve toll-like receptor-related pathways

Accumulating evidence suggests that activation of microglia plays a key role in the pathogenesis of depression. Activated microglia produce a wide range of factors whose prolonged or excessive release may lead to brain disorders. Thus, the inhibition of microglial cells may be beneficial in the treatment of depressive diseases. Tianeptine is an atypical antidepressant drug with proven clinical efficacy, but its mechanism of action remains still not fully understood. In the present study, using microglial cultures we investigated whether tianeptine modifies microglial activation after lipopolysaccharide (LPS) stimulation and which intracellular pathways are involved in the activity of this antidepressant. Our study shows that tianeptine attenuated the LPS-evoked inflammatory activation of microglia by decreasing the expression of proinflammatory cytokines such as IL-1β, IL-18, IL-6 and tumor necrosis factor α (TNF-α), the release of nitric oxide (NO) and reactive oxygen species (ROS) as well as the expression of inducible nitric oxide synthase. Analyses of signaling pathways demonstrate that tianeptine led to the suppression of LPS-induced TLR4 expression and ERK1/2 phosphorylation. Furthermore, our study reveals the inhibitory impact of tianeptine on caspase-3-induced PKCδ degradation and consequently on the activation of NF-κB factor in microglial cells. Taken together, present results show anti-inflammatory properties of tianeptine in microglial cultures stimulated by LPS. This study provides evidence that the inhibition of microglial activation may underlie the therapeutic activity of tianeptine. Our findings show the anti-inflammatory effect of tianeptine (TIA) in lipopolisaccharide (LPS)-stimulated microglial cells. The beneficial tianeptine action is mediated through the inhibition of Toll-like receptor 4 (TLR4) expression as well as the TLR4-related pathways: extracellular signal-regulated kinase 1/2 (ERK1/2), caspase-3-dependent protein kinase δ (PKCδ) cleavage and the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings may provide a new therapeutic strategy for treatment of disorders based on neuroinflammation, including depression.

Common Genetic Polymorphisms within NFκB-Related Genes and the Risk of Developing Invasive Aspergillosis

Invasive Aspergillosis (IA) is an opportunistic infection caused by Aspergillus, a ubiquitously present airborne pathogenic mold. A growing number of studies suggest a major host genetic component in disease susceptibility. Here, we evaluated whether 14 single-nucleotide polymorphisms within NFκB1, NFκB2, RelA, RelB, Rel, and IRF4 genes influence the risk of IA in a population of 834 high-risk patients (157 IA and 677 non-IA) recruited through a collaborative effort involving the aspBIOmics consortium and four European clinical institutions. No significant overall associations between selected SNPs and the risk of IA were found in this large cohort. Although a hematopoietic stem cell transplantation (HSCT)-stratified analysis revealed that carriers of the IRF4_{rs12203592T/T} genotype had a six-fold increased risk of developing the infection when compared with those carrying the C allele (OR_REC = 6.24, 95%CI 1.25–31.2, P = 0.026), the association of this variant with IA risk did not reach significance at experiment-wide significant threshold. In addition, we found an association of the IRF4_AATC and IRF4_GGTC haplotypes (not including the IRF4_rs12203592T risk allele) with a decreased risk of IA but the magnitude of the association was similar to the one observed in the single-SNP analysis, which indicated that the haplotypic effect on IA risk was likely due to the IRF4_rs12203592 SNP. Finally, no evidence of significant interactions among the genetic markers tested and the risk of IA was found. These results suggest that the SNPs on the studied genes do not have a clinically relevant impact on the risk of developing IA.

Medical ozone increases methotrexate clinical response and improves cellular redox balance in patients with rheumatoid arthritis

Medical ozone reduced inflammation, IL-1β, TNF-α mRNA levels and oxidative stress in PG/PS-induced arthritis in rats. The aim of this study was to investigate the medical ozone effects in patients with rheumatoid arthritis treated with methotrexate and methotrexate+ozone, and to compare between them. A randomized clinical study with 60 patients was performed, who were divided into two groups: one (n=30) treated with methotrexate (MTX), folic acid and Ibuprophen (MTX group) and the second group (n=30) received the same as the MTX group+medical ozone by rectal insufflation of the gas (MTX+ozone group). The clinical response of the patients was evaluated by comparing Disease Activity Score 28 (DAS28), Health Assessment Questionnaire Disability Index (HAQ-DI), Anti-Cyclic Citrullinated (Anti-CCP) levels, reactants of acute phase and biochemical markers of oxidative stress before and after 20 days of treatment. MTX+ozone reduced the activity of the disease while MTX merely showed a tendency to decrease the variables. Reactants of acute phase displayed a similar picture. MTX+ozone reduced Anti-CCP levels as well as increased antioxidant system, and decreased oxidative damage whereas MTX did not change. Glutathione correlated with all clinical variables just after MTX+ozone. MTX+ozone increased the MTX clinical response in patients with rheumatoid arthritis. No side effects were observed. These results suggest that ozone can increase the efficacy of MTX probably because both share common therapeutic targets. Medical ozone treatment is capable of being a complementary therapy in the treatment of rheumatoid arthritis.

E3 Ubiquitin ligase RNF183 Is a Novel Regulator in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Specific members of the RING finger [RNF] protein family serve as E3 ubiquitin ligases and play important roles in the regulation of inflammation. However, their roles in the pathogenesis of inflammatory bowel disease [IBD] have not been explored.

METHODS

Genomic microarray of inflamed colon samples from Crohn's disease [CD] patients was performed to identify potential up-regulated genes. Expression of the identified highly up-regulated RNF183 gene was subsequently examined by quantitative reverse transcription polymerase chain reaction [qRT-PCR], western blotting and immunohistochemistry of the intestinal tissues of IBD patients and the colons of trinitrobenzene sulphonic acid [TNBS]-induced colitic mice. RNF183-mediated interaction with the NF-κB pathway and ubiquitination of IκBα were examined by siRNA, plasmid transfection, and immunoprecipitation. The miRNA predicted to target RNF183 was explored and its role in the RNF183/ NF-κB pathway was investigated.

RESULTS

RNF183 was up-regulated in intestinal epithelial cells in IBD patients and in colitic mice. RNF183 promoted intestinal inflammation via the activation of the NF-κB pathway by increasing the ubiquitination and degradation of IκBα. Computational analysis identified putative binding of miR-7 to RNF183. Transfection of intestinal cells with a miR-7 mimic or inhibitor confirmed its negative regulatory effect on RNF183 expression and ubiquitination of IκBα. miR-7 was down-regulated in inflamed colon tissues of IBD patients and colitic mice.

CONCLUSIONS

RNF183, which is negatively regulated by miR-7, is a novel regulator promoting intestinal inflammation by increasing the ubiquitination and degradation of IκBα, thereby inducing NF-κB activation. The interaction between RNF183-mediated ubiquitination and miRNA may be an important novel epigenetic mechanism in the pathogenesis of IBD.

The Activation of NF-κB in Infiltrated Mononuclear Cells Negatively Correlates with Treg Cell Frequency in Oral Lichen Planus

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory mucosal disease with persistent accumulation of T cells in the lamina propria. Nuclear factor-kappa B (NF-κB) is a major regulator of immune responses, and NF-κB-dependent cytokines and pro-inflammatory mediators can be detected in higher levels in the saliva and serum from patients with OLP. CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells play an important role in the prevention of autoimmune pathology by regulating the immune response. To explore the correlation between NF-κB p65 activation and accumulation of Treg cells in patients with OLP, 40 ethnic Chinese patients with OLP and 10 healthy volunteers were recruited. The nuclear expression of NF-κB p65 in infiltrated mononuclear cells and Treg cells in the OLP lesion and the normal oral mucosa (NOM) was analyzed by immunohistochemistry assay. Our results showed that both the nuclear expression of NF-κB p65 and the number of Foxp3(+) Treg were higher in the OLP lesions. Furthermore, the frequency of Treg cells was negatively correlated with NF-κB nuclear expression in subepithelial lymphocytic infiltrate of the OLP lesion. This finding provides a new insight into the pathogenesis of OLP and may contribute to novel therapeutic strategies for the treatment of OLP by modulating the immune system.

Black ginseng-enriched Chong-Myung-Tang extracts improve spatial learning behavior in rats and elicit anti-inflammatory effects in vitro

Background

Chong-Myung-Tang (CMT) extract is widely used in Korea as a traditional herbal tonic for increasing memory capacity in high-school students and also for numerous body ailments since centuries. The use of CMT to improve the learning capacity has been attributed to various plant constituents, especially black ginseng, in it. Therefore, in this study, we have first investigated whether black ginseng-enriched CMT extracts affected spatial learning using the Morris water maze (MWM) test. Their molecular mechanism of action underlying improvement of learning and memory was examined in vitro.

Methods

We used two types of black ginseng-enriched CMT extracts, designated as CM-1 and CM-2, and evaluated their efficacy in the MWM test for spatial learning behavior and their anti-inflammatory effects in BV2 microglial cells.

Results

Our results show that both black ginseng-enriched CMT extracts improved the learning behavior in scopolamine-induced impairment in the water maze test. Moreover, these extracts also inhibited nitric oxide production in BV2 cells, with significant suppression of expression of proinflammatory cytokines, especially inducible nitric oxide synthase, cyclooxygenase-2, and interleukin-1β. The protein expression of mitogen-activated protein kinase and nuclear factor-κB pathway factors was also diminished by black ginseng-enriched CMT extracts, indicating that it not only improves the memory impairment, but also acts a potent anti-inflammatory agent for neuroinflammatory diseases.

Conclusion

Our research for the first time provides the scientific evidence that consumption of black ginseng-enriched CMT extract as a brain tonic improves memory impairment. Thus, our study results can be taken as a reference for future neurobehavioral studies.

Expression of TLR-7, MyD88, NF-kB, and INF-α in B Lymphocytes of Mayan Women with Systemic Lupus Erythematosus in Mexico

Background

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease involving multiple organs. It is currently accepted that several genetic, environmental, and hormonal factors are contributing to its development. Innate immunity may have a great influence in autoimmunity through Toll-like receptors. TLR-7 recognizing single-strand RNA has been involved in SLE. Its activation induces intracellular signal with attraction of MyD88 and NF-kBp65, leading to IFN-α synthesis which correlate with disease activity.

Objective

To assess the expression of TLR-7, MyD88, and NF-kBp65 in B lymphocytes of Mayan women with SLE.

Methods

One hundred patients with SLE and 100 healthy controls, all of them Mayan women, were included. TLR-7 was analyzed on B and T lymphocytes, and MyD88 and NF-kB only in B lymphocytes. Serum INF-α level was evaluated by ELISA.

Results

Significant expression (p < 0.0001) of TLR-7 in B and T lymphocytes and serum IFN-α increased (p = 0.034) was observed in patients. MyD88 and NF-kBp65 were also increased in B lymphocytes of patients. TLR-7 and NF-kBp65 expression correlated, but no correlation with INF-α and disease activity was detected.

Conclusion

Data support the role of TLR-7 and signal proteins in the pathogenesis of SLE in the Mayan population of Yucatán.

Receptor-Interacting Protein Kinase-2 Inhibition by CYLD Impairs Antibacterial Immune Responses in Macrophages

Upon infection with intracellular bacteria, nucleotide oligomerization domain protein 2 recognizes bacterial muramyl dipeptide and binds, subsequently, to receptor-interacting serine/threonine kinase 2 (RIPK2), which activates immune responses via the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) and extracellular signal-regulated kinase (ERK) pathways. Activation of RIPK2 depends on its K63 ubiquitination by E3 ligases, whereas the deubiquitinating enzyme A20 counter regulates RIPK2 activity by cleaving K63-polyubiquitin chains from RIPK2. Here, we newly identify the deubiquitinating enzyme CYLD as a new inhibitor of RIPK2. We show that CYLD binds to and removes K63-polyubiquitin chains from RIPK2 in Listeria monocytogenes (Lm) infected murine bone marrow-derived macrophages. CYLD-mediated K63 deubiquitination of RIPK2 resulted in an impaired activation of both NF-κB and ERK1/2 pathways, reduced production of proinflammatory cytokines interleukin-6 (IL-6), IL-12, anti-listerial reactive oxygen species (ROS) and nitric oxide (NO), and, finally, impaired pathogen control. In turn, RIPK2 inhibition by siRNA prevented activation of NF-κB and ERK1/2 and completely abolished the protective effect of CYLD deficiency with respect to the production of IL-6, NO, ROS, and pathogen control. Noteworthy, CYLD also inhibited autophagy of Listeria in a RIPK2-ERK1/2-dependent manner. The protective function of CYLD deficiency was dependent on interferon gamma (IFN-γ) prestimulation of infected macrophages. Interestingly, the reduced NF-κB activation in CYLD-expressing macrophages limited the protective effect of IFN-γ by reducing NF-κB-dependent signal transducers and activators of transcription-1 (STAT1) activation. Taken together, our study identifies CYLD as an important inhibitor of RIPK2-dependent antibacterial immune responses in macrophages.

Porcine lactoferrin-derived peptide LFP-20 protects intestinal barrier by maintaining tight junction complex and modulating inflammatory response

LFP-20, a 20-amino acid antimicrobial peptide in the N terminus of porcine lactoferrin, has antimicrobial and immunomodulatory activities. This study assessed the protective effects of LFP-20 on LPS-induced intestinal damage in a LPS-induced mouse model and in vitro, using intestinal porcine epithelial cell line 1 (IPEC-1) cells. LFP-20 prevented LPS-induced impairment in colon epithelium tissues, infiltration of macrophages or leukocytes, histological evidence of inflammation and increased levels of TNF-a, IL-6 and IFN-γ. LFP-20 increased the expression of zonula occludens-1, occludin and claudin-1 and reduced permeability as well as apoptosis of the colon in LPS-treated mice. In IPEC-1 cells, LFP-20 increased transepithelial electrical resistance and tight junction expression. Moreover, we found LFP-20 decreased the MyD88 and AKT levels to affect the NF-κB signaling pathway, to modulate inflammation response and tight junction networks in the processing of LPS stimulation. In summary, LFP-20 prevents the inflammatory response and disruption of tight junction structure induced by LPS, suggesting the potential use of LFP-20 as a prophylactic agent to protect intestinal barrier function.

NFKB1: a suppressor of inflammation, ageing and cancer

The pleiotropic consequences of nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) pathway activation result from the combinatorial effects of the five subunits that form the homo- and heterodimeric NF-κB complexes. Although biochemical and gene knockout studies have demonstrated overlapping and distinct functions for these proteins, much is still not known about the mechanisms determining context-dependent functions, the formation of different dimer complexes and transcriptional control in response to diverse stimuli. Here we discuss recent results that reveal that the nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NFKB1) (p105/p50) subunit is an important regulator of NF-κB activity in vivo. These effects are not restricted to being a dimer partner for other NF-κB subunits. Rather p50 homodimers have a critical role as suppressors of the NF-κB response, while the p105 precursor has a variety of NF-κB-independent functions. The importance of Nfkb1 function can be seen in mouse models, where Nfkb1(-/-) mice display increased inflammation and susceptibility to certain forms of DNA damage, leading to cancer, and a rapid ageing phenotype. In humans, low expression of Kip1 ubiquitination-promoting complex 1 (KPC1), a ubiquitin ligase required for p105 to p50 processing, was shown to correlate with a reduction in p50 and glioblastoma incidence. Therefore, while the majority of research in this field has focused on the upstream signalling pathways leading to NF-κB activation or the function of other NF-κB subunits, such as RelA (p65), these data demonstrate a critical role for NFKB1, potentially revealing new strategies for targeting this pathway in inflammatory diseases and cancer.

Evaluating Nuclear Factor NF-κB Activation following Bone Trauma: A Pilot Study in a Wistar Rats Model

The present study investigated the moment of peak NF-kB activation and its dissipation in the cortical bone in the femur of Wistar rat stimulated by surgical trauma. Sixty-five Wistar rats were divided into 13 groups (n = 5 per group): eight experimental groups (expG 1–8) divided based on the euthanasia time point (zero, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h and 24 h) and five sham control groups (conG 1–5) killed at zero, 1 h, 2 h, 4 h and 6 h, respectively. A 1.8-mm-diameter defect was generated 0.5 mm from the femur proximal joint using a round bur to induce the surgical trauma. Overall, the activation peak of NF-κB in the cortical bone was 6 h (expG5 group) independent of the evaluated position; this peak was significantly different compared to those in the other groups (p < 0.05). The surgical trauma resulted in a spread of immune markings throughout the cortical bone with an accentuation in the knee region. The present study provides the first evidence that the NF-κB activation peak was established after 6 hours in the cortical bone of Wistar rats. The signs from a surgical trauma can span the entire cortical bone and are not limited to the damaged region.

A Novel Korean Red Ginseng Compound Gintonin Inhibited Inflammation by MAPK and NF-κB Pathways and Recovered the Levels of mir-34a and mir-93 in RAW 264.7 Cells

The beneficial health promoting effects of ginseng from vitalizing the body to enhancing long life have been well explored very rapidly in the past few years. Up till now many ginsenosides have been discovered for their marvelous therapeutic effects. However during past three years, a novel ginseng compound has been discovered, called gintonin, that differs from other ginsenosides on the basis of its signal transduction and chemical nature. Gintonin has been widely studied for its anti-Alzheimer's disease activities and other neuropathies. However, its anti-inflammatory activity remained unexplored. In our study we have reported for the first time the anti-inflammatory activity of gintonin on RAW 264.7 cells. We found that gintonin potently suppresses the nitric oxide production without any cytotoxicity at given doses and also efficiently suppressed the levels of proinflammatory cytokines. Moreover, it mediaes its signal transduction via MAPK and NF-κB pathways and revives the levels of mir-34a and mir-93. These findings are valuable for the anti-inflammatory effects of this new compound with particular reference to microRNA involvement in the ginseng family.

LFP-20, a porcine lactoferrin peptide, ameliorates LPS-induced inflammation via the MyD88/NF-κB and MyD88/MAPK signaling pathways

LFP-20 is one of the 20 amino acid anti-microbial peptides identified in the N terminus of porcine lactoferrin. Apart from its extensively studied direct anti-bacterial activity, its potential as an activator of immune-related cellular functions is unknown. Therefore, this study investigated its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated pig alveolar macrophages in vitro and systemic inflammation in an in vivo mouse model. We found that the inhibitory effects of LFP-20 on production of pro-inflammatory cytokines were independent of its LPS-binding activity. However, they were associated with NF-κB and MAPK-dependent signaling. Furthermore, LFP-20 might directly influence MyD88 levels to block its interaction with NF-κB and MAPK-dependent signaling molecules that might alter LPS-mediated inflammatory responses in activated macrophages. Taken together, our data indicated that LFP-20 prevents the LPS-induced inflammatory response by inhibiting MyD88/NF-κB and MyD88/MAPK signaling pathways, and sheds light on the potential use of LFP-20 in the therapy of LPS-mediated sepsis.

iTRAQ-based comparative proteomic analysis of Vero cells infected with virulent and CV777 vaccine strain-like strains of porcine epidemic diarrhea virus

The re-emerging porcine epidemic diarrhea virus (PEDV) variant related diarrhea has been documented in China since late 2010 and now with global distribution. Currently, a virulent PEDV CH/YNKM-8/2013 and a CV777 vaccine strain-like AH-M have been successfully isolated from the clinical samples. To dissect out the underlying pathogenic mechanism of virulent PEDV and clarify the differences between virulent and CV777 vaccine strain-like PEDV infections, we performed an iTRAQ-based comparative quantitative proteomic study of Vero cells infected with both PEDV strains. A total of 661 and 474 differentially expressed proteins were identified upon virulent and CV777 vaccine strain-like isolates infection, respectively. Ingenuity Pathway Analysis was employed to investigate the canonical pathways and functional networks involved in both PEDV infections. Comprehensive studies have revealed that the PEDV virulent strain suppressed protein synthesis of Vero cells through down-regulating mTOR as well as its downstream targets 4EBP1 and p70S6K activities, which were validated by immunoblotting. In addition, the virulent strain could activate NF-κB pathway more intensively than the CV777 vaccine strain-like isolate, and elicit stronger inflammatory cascades as well. These data might provide new insights for elucidating the specific pathogenesis of PEDV infection, and pave the way for the development of effective therapeutic strategies.

Biological significance

Porcine epidemic diarrhea is now worldwide distributed and causing huge economic losses to swine industry. The immunomodulation and pathogenesis between PEDV and host, as well as the difference between virulent and attenuated strains of PEDV infections are still largely unknown. In this study, we presented for the first application of proteomic analysis to compare whole cellular protein alterations induced by virulent and CV777 vaccine strain-like PEDV infections, which might contribute to understand the pathogenesis of PEDV and anti-viral strategy development.

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Vero cells proteome was individually analyzed upon virulent and attenuated PEDV infections.

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Many pathways and interactive networks were constructed based on differentially expressed proteins.

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Virulent PEDV strain suppressed mTOR as well as its downstream targets 4EBP1 and p70S6K activities.

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Virulent PEDV strain activated NF-κB pathway more intensively than the attenuated isolate.

The IκB kinase inhibitor ACHP strongly attenuates TGFβ1-induced myofibroblast formation and collagen synthesis

Excessive accumulation of a collagen‐rich extracellular matrix (ECM) by myofibroblasts is a characteristic feature of fibrosis, a pathological state leading to serious organ dysfunction. Transforming growth factor beta1 (TGFβ1) is a strong inducer of myofibroblast formation and subsequent collagen production. Currently, there are no remedies for the treatment of fibrosis. Activation of the nuclear factor kappa B (NF‐κB) pathway by phosphorylating IκB with the enzyme IκB kinase (IKK) plays a major role in the induction of fibrosis. ACHP {2‐Amino‐6‐[2‐(cyclopropylmethoxy)‐6‐hydroxyphenyl]‐4‐(4‐piperidinyl)‐3 pyridinecarbonitrile}, a selective inhibitor of IKK, prohibits the activation of the NF‐κB pathway. It is not known whether ACHP has potential anti‐fibrotic properties. Using adult human dermal and lung fibroblasts we have investigated whether ACHP has the ability to inhibit the TGFβ1‐induced transition of fibroblasts into myofibroblasts and its excessive synthesis of ECM. The presence of ACHP strongly suppressed the induction of the myofibroblast markers alpha‐smooth muscle actin (αSMA) and SM22α, as well as the deposition of the ECM components collagen type I and fibronectin. Furthermore, post‐treatment with ACHP partly reversed the expression of αSMA and collagen type I production. Finally, ACHP suppressed the expression of the three collagen‐modifying enzymes lysyl hydroxylase (PLOD1,PLOD2 and PLOD3) in dermal fibroblasts, but did not do so in lung fibroblasts. We conclude that the IKK inhibitor ACHP has potent antifibrotic properties, and that the NF‐κB pathway plays an important role in myofibroblast biology.

Impaired Vitamin D Signaling in Endothelial Cell Leads to an Enhanced Leukocyte-Endothelium Interplay: Implications for Atherosclerosis Development

Endothelial cell activation leading to leukocyte recruitment and adhesion plays an essential role in the initiation and progression of atherosclerosis. Vitamin D has cardioprotective actions, while its deficiency is a risk factor for the progression of cardiovascular damage. Our aim was to assess the role of basal levels of vitamin D receptor (VDR) on the early leukocyte recruitment and related endothelial cell-adhesion-molecule expression, as essential prerequisites for the onset of atherosclerosis. Knockdown of VDR in endothelial cells (shVDR) led to endothelial cell activation, characterized by upregulation of VCAM-1, ICAM-1 and IL-6, decreased peripheral blood mononuclear cell (PBMC) rolling velocity and increased PBMC rolling flux and adhesion to the endothelium. shVDR cells showed decreased IκBα levels and accumulation of p65 in the nucleus compared to shRNA controls. Inhibition of NF-κB activation with super-repressor IκBα blunted all signs of endothelial cell activation caused by downregulation of VDR in endothelial cells. In vivo, deletion of VDR led to significantly larger aortic arch and aortic root lesions in apoE^-/- mice, with higher macrophage content. apoE^-/-VDR^-/-mice showed higher aortic expression of VCAM-1, ICAM-1 and IL-6 when compared to apoE^-/-VDR^+/+ mice. Our data demonstrate that lack of VDR signaling in endothelial cells leads to a state of endothelial activation with increased leukocyte-endothelial cell interactions that may contribute to the more severe plaque accumulation observed in apoE^-/-VDR^-/- mice. The results reveal an important role for basal levels of endothelial VDR in limiting endothelial cell inflammation and atherosclerosis.

Acute TNF-induced repression of cell identity genes is mediated by NFκB-directed redistribution of cofactors from super-enhancers

The proinflammatory cytokine tumor necrosis factor (TNF) plays a central role in low-grade adipose tissue inflammation and development of insulin resistance during obesity. In this context, nuclear factor κ-light-chain-enhancer of activated B cells (NFκB) is directly involved and required for the acute activation of the inflammatory gene program. Here, we show that the major transactivating subunit of NFκB, v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA), is also required for acute TNF-induced suppression of adipocyte genes. Notably, this repression does not involve RELA binding to the associated enhancers but rather loss of cofactors and enhancer RNA (eRNA) selectively from high-occupancy sites within super-enhancers. Based on these data, we have developed models that, with high accuracy, predict which enhancers and genes are repressed by TNF in adipocytes. We show that these models are applicable to other cell types where TNF represses genes associated with super-enhancers in a highly cell-type–specific manner. Our results propose a novel paradigm for NFκB-mediated repression, whereby NFκB selectively redistributes cofactors from high-occupancy enhancers, thereby specifically repressing super-enhancer-associated cell identity genes.

Rosuvastatin improves hepatopulmonary syndrome through inhibition of inflammatory angiogenesis of lung

The hepatopulmonary syndrome (HPS) is characterized by hypoxia and increased intrapulmonary shunts in cirrhotic patients. Emerging evidence showed promising results of treating HPS by abolishment of intrapulmonary inflammation and angiogenesis. Rosuvastatin is a kind of 3-hydroxy-methyl-3-glutamyl coenzyme A reductase inhibitor. In addition to lipid-lowering effects, it has anti-inflammation and anti-angiogenesis properties. We postulated that rosuvastatin treatment can ameliorate HPS. Common bile duct ligation (CBDL) was applied in an experimental HPS animal model. CBDL rats received 2-week rosuvastatin (20 mg/kg/day) treatments from the fifteenth day after operation. The haemodynamic data, blood gas analysis, liver biochemistries, tumour necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were examined after rosuvastatin treatment. The liver and lung tissues were dissected for histopathological studies and protein analyses. In the parallel groups, intrapulmonary shunts were determined. The haemodynamic and liver biochemistries were not changed after rosuvastatin treatment in CBDL rats, but the alveolar-arterial oxygen pressure gradient was significantly decreased, implying that HPS-induced hypoxia was reversed after rosuvastatin treatment. In addition, rosuvastatin treatment reduced intrapulmonary shunts and plasma levels of VEGF and TNF-α. Besides, the intrapulmonary protein expression of nuclear factor kappa B (NF-κB), VEGF receptor (VEGFR)-1,2 and Rho-associated A kinase were significantly down-regulated and the intrapulmonary angiogenesis was ameliorated. We concluded that rosuvastatin alleviates experimental HPS through blockade of pulmonary inflammatory angiogenesis via TNF-α/NF-κB and VEGF/Rho-associated A kinase pathways down-regulation.

Dynamic imaging of pancreatic nuclear factor κB (NF-κB) activation in live mice using adeno-associated virus (AAV) infusion and bioluminescence

Nuclear factor κB (NF-κB) is an important signaling molecule that plays a critical role in the development of acute pancreatitis. Current methods for examining NF-κB activation involve infection of an adenoviral NF-κB-luciferase reporter into cell lines or electrophoretic mobility shift assay of lysate. The use of adeno-associated viruses (AAVs) has proven to be an effective method of transfecting whole organs in live animals. We examined whether intrapancreatic duct infusion of AAV containing an NF-κB-luciferase reporter (AAV-NF-κB-luciferase) can reliably measure pancreatic NF-κB activation. We confirmed the infectivity of the AAV-NF-κB-luciferase reporter in HEK293 cells using a traditional luciferase readout. Mice were infused with AAV-NF-κB-luciferase 5 weeks before induction of pancreatitis (caerulein, 50 μg/kg). Unlike transgenic mice that globally express NF-κB-luciferase, AAV-infused mice showed a 15-fold increase in pancreas-specific NF-κB bioluminescence following 12 h of caerulein compared with baseline luminescence (p < 0.05). The specificity of the NF-κB-luciferase signal to the pancreas was confirmed by isolating the pancreas and adjacent organs and observing a predominant bioluminescent signal in the pancreas compared with liver, spleen, and stomach. A complementary mouse model of post-ERCP-pancreatitis also induced pancreatic NF-κB signals. Taken together these data provide the first demonstration that NF-κB activation can be examined in a live, dynamic fashion during pancreatic inflammation. We believe this technique offers a valuable tool to study real-time activation of NF-κB in vivo.

The novel S59P mutation in the TNFRSF1A gene identified in an adult onset TNF receptor associated periodic syndrome (TRAPS) constitutively activates NF-κB pathway

Introduction

Mutations in the TNFRSF1A gene, encoding tumor necrosis factor receptor 1 (TNF-R1), are associated with the autosomal dominant autoinflammatory disorder, called TNF receptor associated periodic syndrome (TRAPS). TRAPS is clinically characterized by recurrent episodes of long-lasting fever and systemic inflammation. A novel mutation (c.262 T > C; S59P) in the TNFRSF1A gene at residue 88 of the mature protein was recently identified in our laboratory in an adult TRAPS patient. The aim of this study was to functionally characterize this novel TNFRSF1A mutation evaluating its effects on the TNF-R1-associated signaling pathways, firstly NF-κB, under particular conditions and comparing the results with suitable control mutations.

Methods

HEK-293 cell line was transfected with pCMV6-AC construct expressing wild-type (WT) or c.262 T > C (S59P), c.362G > A (R92Q), c.236C > T (T50M) TNFRSF1A mutants. Peripheral blood mononuclear cells (PBMCs) were instead isolated from two TRAPS patients carrying S59P and R92Q mutations and from five healthy subjects. Both transfected HEK-293 and PBMCs were stimulated with tumor necrosis factor (TNF) or interleukin 1β (IL-1β) to evaluate the expression of TNF-R1, the activation of TNF-R1-associated downstream pathways and the pro-inflammatory cytokines by means of immunofluorescent assay, array-based technique, immunoblotting and immunometric assay, respectively.

Results

TNF induced cytoplasmic accumulation of TNF-R1 in all mutant cells. Furthermore, all mutants presented a particular set of active TNF-R1 downstream pathways. S59P constitutively activated IL-1β, MAPK and SRC/JAK/STAT3 pathways and inhibited apoptosis. Also, NF-κB pathway involvement was demonstrated in vitro by the enhancement of p-IκB-α and p65 nuclear subunit of NF-κB expression in all mutants in the presence of TNF or IL-1β stimulation. These in vitro results correlated with patients’ data from PBMCs. Concerning the pro-inflammatory cytokines secretion, mainly IL-1β induced a significant and persistent enhancement of IL-6 and IL-8 in PBMCs carrying the S59P mutation.

Conclusions

The novel S59P mutation leads to defective cellular trafficking and to constitutive activation of TNF-R1. This mutation also determines constitutive activation of the IL-1R pathway, inhibition of apoptosis and enhanced and persistent NF-κB activation and cytokine secretion in response to IL-1β stimulation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0604-7) contains supplementary material, which is available to authorized users.

Bovine immunoglobulin/protein isolate binds pro-inflammatory bacterial compounds and prevents immune activation in an intestinal co-culture model

Intestinal barrier dysfunction is associated with chronic gastrointestinal tract inflammation and diseases such as IBD and IBS. Serum-derived bovine immunoglobulin/protein isolate (SBI) is a specially formulated protein preparation (>90%) for oral administration. The composition of SBI is greater than 60% immunoglobulin including contributions from IgG, IgA, and IgM. Immunoglobulin within the lumen of the gut has been recognized to have anti-inflammatory properties and is involved in maintaining gut homeostasis. The binding of common intestinal antigens (LPS and Lipid A) and the ligand Pam3CSK4, by IgG, IgA, and IgM in SBI was shown using a modified ELISA technique. Each of these antigens stimulated IL-8 and TNF-α cytokine production by THP-1 monocytes. Immune exclusion occurred as SBI (≤50 mg/mL) bound free antigen in a dose dependent manner that inhibited cytokine production by THP-1 monocytes in response to 10 ng/mL LPS or 200 ng/mL Lipid A. Conversely, Pam3CSK4 stimulation of THP-1 monocytes was unaffected by SBI/antigen binding. A co-culture model of the intestinal epithelium consisted of a C2BBe1 monolayer separating an apical compartment from a basal compartment containing THP-1 monocytes. The C2BBe1 monolayer was permeabilized with dimethyl palmitoyl ammonio propanesulfonate (PPS) to simulate a damaged epithelial barrier. Results indicate that Pam3CSK4 was able to translocate across the PPS-damaged C2BBe1 monolayer. However, binding of Pam3CSK4 by immunoglobulins in SBI prevented Pam3CSK4 translocation across the damaged C2BBe1 barrier. These results demonstrated steric exclusion of antigen by SBI which prevented apical to basal translocation of antigen due to changes in the physical properties of Pam3CSK4, most likely as a result of immunoglobulin binding. This study demonstrates that immunoglobulins in SBI can reduce antigen-associated inflammation through immune and steric exclusion mechanisms and furthers the mechanistic understanding of how SBI might improve immune status and reduce inflammation in various intestinal disease states.

Orphan receptor IL-17RD regulates Toll-like receptor signalling via SEFIR/TIR interactions

Receptor families of the innate immune response engage in 'cross-talk' to tailor optimal immune responses against invading pathogens. However, these responses are subject to multiple levels of regulation to keep in check aberrant inflammatory signals. Here, we describe a role for the orphan receptor interleukin-17 receptor D (IL-17RD) in negatively regulating Toll-like receptor (TLR)-induced responses. Deficiency of IL-17RD expression in cells leads to enhanced pro-inflammatory signalling and gene expression in response to TLR stimulation, and Il17rd(-/-) mice are more susceptible to TLR-induced septic shock. We demonstrate that the intracellular Sef/IL-17R (SEFIR) domain of IL-17RD targets TIR adaptor proteins to inhibit TLR downstream signalling thus revealing a paradigm involving cross-regulation of members of the IL-17R and TLR families.

Porcine epidemic diarrhea virus infection induces NF-κB activation through the TLR2, TLR3 and TLR9 pathways in porcine intestinal epithelial cells

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that induces persistent diarrhoea in swine, resulting in severe economic losses in swine-producing countries. Insights into the interplay between PEDV infection and the innate immune system are necessary for understanding the associated mechanism of pathogenesis. The transcription factor NF-κB plays an important role in regulating host immune responses. Here, we elucidated for the first time to our knowledge the potential mechanism of PEDV-mediated NF-κB activation in porcine small intestinal epithelial cells (IECs). During PEDV infection, NF-κB p65 was found to translocate from the cytoplasm to the nucleus, and PEDV-dependent NF-κB activity was associated with viral dose and active replication. Using small interfering RNAs to screen different mRNA components of the Toll-like receptor (TLR) or RIG-I-like receptor signalling pathways, we demonstrated that TLR2, TLR3 and TLR9 contribute to NF-κB activation in response to PEDV infection, but not RIG-I. By screening PEDV structural proteins for their ability to induce NF-κB activities, we found that PEDV nucleocapsid protein (N) could activate NF-κB and that the central region of N was essential for NF-κB activation. Furthermore, TLR2 was involved in PEDV N-induced NF-κB activation in IECs. Collectively, these findings provide new avenues of investigation into the molecular mechanisms of NF-κB activation induced by PEDV infection.

Indoline-3-propionate and 3-aminopropyl carbamates reduce lung injury and pro-inflammatory cytokines induced in mice by LPS

BACKGROUND AND PURPOSE

In the search for safer and effective anti-inflammatory agents, we investigated the effect of methyl indoline-3-propionate and indoline-3-(3-aminopropyl) carbamates on LPS-induced lung injury and pro-inflammatory cytokines in mice. Their mechanism of action was determined in murine peritoneal macrophages.

EXPERIMENTAL APPROACH

Lung injury was induced by intratracheal infusion of LPS and assessed by the change in lung weight and structure by light microscopy after staining by haematoxylin and eosin. In LPS-activated macrophages, MAPK proteins and IκBα were measured by Western blotting and the transcription factors, AP-1 and NF-κB by electromobility shift assay. Cytokines in the plasma and spleen of mice injected with LPS were measured by elisa-based assay.

KEY RESULTS

AN917 and AN680 (1-10 pM) decreased TNF-α protein in macrophages by inhibiting phosphorylation of p38 MAPK, IκBα degradation and activation of AP-1 and NF-κB without affecting cell viability. In vivo, these compounds (10 μmol · kg(-1)) markedly decreased lung injury induced by LPS and the elevation of TNF-α and IL-6 in lung, plasma and spleen. Activation of α-7nACh receptors contributed to the reduction of TNF-α by AN917, which inhibited AChE in the spleen by 35%.

CONCLUSION AND IMPLICATIONS

Indoline carbamates are potent inhibitors of pro-inflammatory mediators in murine macrophages and in mice injected with LPS, acting via the p38 MAPK, AP-1 and NF-κB cascades. Indirect α-7nACh receptor activation by AN917, through inhibition of AChE, contributes to its anti-inflammatory effect. Indoline carbamates may have therapeutic potential for lung injury and other diseases associated with chronic inflammation without causing immunosuppression.

Review on molecular and chemopreventive potential of nimbolide in cancer

Cancer is the most dreaded disease in human and also major health problem worldwide. Despite its high occurrence, the exact molecular mechanisms of the development and progression are not fully understood. The existing cancer therapy based on allopathic medicine is expensive, exhibits side effects; and may also alter the normal functioning of genes. Thus, a non-toxic and effective mode of treatment is needed to control cancer development and progression. Some medicinal plants offer a safe, effective and affordable remedy to control the cancer progression. Nimbolide, a limnoid derived from the neem (Azadirachta indica) leaves and flowers of neem, is widely used in traditional medical practices for treating various human diseases. Nimbolide exhibits several pharmacological effects among which its anticancer activity is the most promising. The previous studies carried out over the decades have shown that nimbolide inhibits cell proliferation and metastasis of cancer cells. This review highlights the current knowledge on the molecular targets that contribute to the observed anticancer activity of nimbolide related to induction of apoptosis and cell cycle arrest; and inhibition of signaling pathways related to cancer progression.

Activation of apoptosis by caspase-3-dependent specific RelB cleavage in anticancer agent-treated cancer cells: involvement of positive feedback mechanism

DTCM-glutarimide (DTCM-G) is a newly found anti-inflammatory agent. In the course of experiments with lymphoma cells, we found that DTCM-G induced specific RelB cleavage. Anticancer agent vinblastine also induced the specific RelB cleavage in human fibrosarcoma HT1080 cells. The site-directed mutagenesis analysis revealed that the Asp205 site in RelB was specifically cleaved possibly by caspase-3 in vinblastine-treated HT1080 cells. Moreover, the cells stably overexpressing RelB Asp205Ala were resistant to vinblastine-induced apoptosis. Thus, the specific Asp205 cleavage of RelB by caspase-3 would be involved in the apoptosis induction by anticancer agents, which would provide the positive feedback mechanism.

Anti-inflammatory effect of methylpenicinoline from a marine isolate of Penicillium sp. (SF-5995): inhibition of NF-κB and MAPK pathways in lipopolysaccharide-induced RAW264.7 macrophages and BV2 microglia

In the course of a search for anti-inflammatory metabolites from marine-derived fungi, methylpenicinoline (1) was isolated from a marine isolate of Penicillin sp. Compound 1 inhibited lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production by suppressing the expression of inducible NO synthase (iNOS) in RAW264.7 macrophages and BV2 microglia. It also attenuated prostaglandin E₂ (PGE₂) production by suppressing cyclooxygenase-2 (COX-2) expression in a concentration-dependent manner (from 10 μM to 80 μM) without affecting cell viability. In addition, compound 1 reduced the production of the pro-inflammatory cytokine interleukin-1β (IL-1β). In a further study designed to elucidate the mechanism of its anti-inflammatory effects, compound 1 was shown to block nuclear factor-kappa B (NF-κB) activation in LPS-induced RAW264.7 macrophages and BV2 microglia by inhibiting the phosphorylation of inhibitor kappa B-α (IκB-α), thereby suppressing the nuclear translocation of NF-κB dimers, namely p50 and p65, that are known to be crucial molecules associated with iNOS and COX-2 expression. In addition, compound 1 inhibited the activation of mitogen-activated protein kinase (MAPK) pathways. Taken together, the results suggest that compound 1 might be a valuable therapeutic agent for the treatment of anti-inflammatory and anti-neuroinflammatory diseases.

2-Hydroxy-3,4-naphthochalcone (2H-NC) inhibits TNFα-induced tumor invasion through the downregulation of NF-κB-mediated MMP-9 gene expression

The control of tumor metastasis is important for the successful prevention and treatment of cancer. Emerging evidence indicates that various natural and synthetic chalcones exhibit antimetastatic activity through the inhibition of nuclear factor-κB (NF-κB), although the precise mechanism by which this occurs is currently unclear. In this study, 2-hydroxy-3,4-naphthochalcone (2H-NC) was found to reduce tumor necrosis factor alpha (TNFα)-induced MMP-9 mRNA expression and gelatinolytic enzyme activity. These actions were associated with inhibition of RelA/p65 NF-κB activity. In addition, 2H-NC inhibited TNFα-induced invasion of MDA-MB-231 breast cancer cells, as assessed using a three-dimensional spheroid invasion assay. Taken together, these data demonstrate that 2H-NC prevents TNFα-induced tumor cell invasion through downregulation of NF-κB-mediated MMP-9 gene expression, and thereby identify naphthochalcones as a potentially effective class of molecules to use as a platform for the development of antimetastatic agents.

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.