Diversity and regulation in the NF-kappaB system

Exploring omics approaches in probiotics: Contemporary developments and prospective pathways

The application of omics technologies in combination with bench investigations has brought about a significant transformation in the field of probiotics, enabling a thorough investigation of the basic elements contributing to the probiotic activity. Genomics studies have decoded the complete set of genes of probiotic organisms, shedding light on beneficial traits and mechanisms of probiotic action. Transcriptomics analyses focus on gene expression patterns and investigate probiotic adaptation and functionality. Proteomic studies have revealed the intricate connections between proteins in probiotic cells and their relationship with the host environment. Metabolomic profiling has provided a comprehensive perspective on the metabolic pathways related to probiotic metabolism and the production of bioactive substances. The ongoing development of omics technology presents exciting opportunities for probiotic research, as it allows for a deeper exploration of probiotic-host interactions and the creation of advanced and tailored probiotics that offer specific health advantages. A comprehensive analysis of recent progress in genomics, transcriptomics, proteomics, and metabolomics related to probiotics is presented in this review.

Identification of key proteins of cytopathic biotype bovine viral diarrhoea virus involved in activating NF-κB pathway in BVDV-induced inflammatory response

Bovine viral diarrhoea virus (BVDV) is the etiologic agent of bovine viral diarrhea-mucosal disease, one of the most important viral diseases in cattle, with inflammatory diarrhea, enteritis, and mucosa necrosis as the major clinical manifestations. NF-κB is an important transcription complex that regulates the expression of genes involved in inflammation and immune responses. NLRP3 inflammasome plays a key role in the development of inflammatory diseases. However, whether the activation of NF-κB is crucial for BVDV infection-induced inflammatory responses remains unclear. The results of our present study showed that BVDV infection significantly activated the NF-κB pathway and promoted the expression of NLRP3 inflammasome components (NLRP3, ASC, pro-caspase 1) as well inflammatory cytokine pro-IL-1β in BVDV-infected bovine cells, resulting in the cleavage of pro-caspase 1 and pro-IL-1β into active form caspase 1 and IL-1β. However, the levels of the NLRP3 inflammasome components and inflammatory cytokines were obviously inhibited, as well the cleavage of pro-caspase 1 and pro-IL-1β in the pre-treated bovine cells with NF-κB-specific inhibitors after BVDV infection. Further, cytopathic biotype BVDV (cpBVDV) Erns and NS5A proteins with their key functional domains contributed to BVDV-induced inflammatory responses via activating the NF-κB pathway were confirmed experimentally. Especially, the NS5A can promote cholesterol synthesis and accelerate its augmentation, further activating the NF-κB signalling pathway. Conclusively, our data elucidate that the activation of NF-κB signaling pathway plays a crucial role in cpBVDV infection-induced inflammatory responses.

Rutin Suppresses DMBA Carcinogenesis in the Breast Through Modulating IL-6/NF-κB, SRC1/HSP90 and ER-α

Rutin dietary supplements may offer pharmacological benefits as anticancer and antiinflammatory properties. This study aimed to investigate the inhibitory and protective effect of rutin on signaling pathways of mammary gland carcinogenesis expermintally induced in female rats by 7,12-di-methyl benz (a) anthracene (DMBA). Results showed that rutin administration ameliorated DMBA toxicity and carcinogic effect on kidney and liver revealed by a significant decrease of urea and creatinine levels, and the activity of the liver enzymes alanine aminotransferase (ALT) and alkaline phosphatase (ALP). The antioxidant state indicated by the total antioxidant capacity (TAC) was significantly increased accompanied by a reduction in the inflammatory markers of interleukin-1β (IL-1B), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) with induction of apoptosis indicated by a significant increase in caspase-3 level. Rutin significantly reduced the levels of the tumor markers carcinoma antigen 15-3 (CA 15-3) and proto-oncogene tyrosine-protein kinase Src1 (Src1). along with downregulation of nuclear factor-kB (NF-κB), heat shock protein 90 (HSP 90), and inducible nitric oxide synthase (iNOS) gene expression. The present study demonstrated the beneficial anticancer activity of rutin as a protective and therapeutic agent. Rutin induces its antitumor activity through elevation of the antioxidant state, inhibition of inflammatory cytokines, downregulation of oncogenes expression, and stimulation of apoptosis.

Effectiveness of the fruit of Rosa odorata sweet var. gigantea (Coll. et Hemsl.) Rehd. et Wils in the protection and the healing of ethanol-induced rat gastric mucosa ulcer based on Nrf2/NF-κB pathway regulation

ETHNOPHARMACOLOGICAL RELEVANCE

Rosa odorata Sweet var. gigantea (Coll. et Hemsl.) Rehd. et Wils (Rosaceae), is also known as "GU-GONG-GUO", the root of which has been recognized as common ethnodrug from the Yi nationality for treating inflammatory bowel disease. The aim of the present study was to investigate the preventive and curative effects of extract from the fruits of Rosa odorata Sweet var. gigantea (Coll.et Hemsl.) Rehd. et Wils (FOE) in vitro and in vivo as well as elucidate the potential mechanisms of the action involved.

MATERIALS AND METHODS

Male Wistar rats were applied to ethanol-induced gastric ulcer model. They were divided into six groups: control, model (GU), positive (Magnesium aluminate chewable tablets, 125 mg/kg), FOE low (125 mg/kg), middle (250 mg/kg) and high (500 mg/kg) doses groups. Histopathology observation of gastric tissues was detected by hematoxylin and eosin (H&E) staining. The expression of Nrf2, HO-1, Keap1, NF-κB p65 and IKKα/β in gastric tissues were evaluated by immunohistochemistry (IHC). The levels of cytokines in serum and tissues were measured by Enzyme-linked immunosorbent assay (ELISA). The expression of Nrf2, HO-1, Keap1, NF-κB p65, IKKα/β, PCNA and COX2 proteins were ulteriorly assessed by Western blotting to elucidate the molecular mechanism of FOE's protective effect on gastric ulcer.

RESULTS

MTT detection showed that LPS reduced RAW264.7 cell survival, and FOE blocked the inhibition of RAW264.7 cell growth induced by LPS. When RAW264.7 cells were treated with both FOE (100 μg mL^-1) and LPS (5 μg mL^-1) for 24 h, compared with the model group, the level of NO, TNF-α, IL-6, IL-1β and MDA significantly decreased, and the activity of SOD was significantly reduced. Obvious pathological injuries in the GU model group were observed, which was improved after treatments with FOE. The contents of pro-inflammatory factors in serum and tissues were decreased by 25% whereas prostaglandin E2 (PGE2) and epidermal growth factor (EGF) were increased by 30% in a dose-dependent manner after FOE (500 mg/kg) treatments. In addition to the promotion effects of superoxide dismutase (SOD), FOE (500 mg/kg) also attenuated the levels of nitric oxide (NO) and malondialdehyde (MDA) by 20%. Likewise, the expression of NF-κB p65, IKKα/β and Keap1 were suppressed after treatments with FOE whereas Nrf2 and HO-1 showed the opposite trend, which mechanisms were found to be associated with Nrf2/NF-κB signaling pathways.

CONCLUSION

The study demonstrated that FOE is able to protect against GU via inhibiting NF-κB signaling pathway and activating Nrf2 signaling pathway, which might provide a stronger theoretical basis for the treatment of GU.

Redox and Inflammatory Signaling, the Unfolded Protein Response, and the Pathogenesis of Pulmonary Hypertension

Protein folding overload and oxidative stress disrupt endoplasmic reticulum (ER) homeostasis, generating reactive oxygen species (ROS) and activating the unfolded protein response (UPR). The altered ER redox state induces further ROS production through UPR signaling that balances the cell fates of survival and apoptosis, contributing to pulmonary microvascular inflammation and dysfunction and driving the development of pulmonary hypertension (PH). UPR-induced ROS production through ER calcium release along with NADPH oxidase activity results in endothelial injury and smooth muscle cell (SMC) proliferation. ROS and calcium signaling also promote endothelial nitric oxide (NO) synthase (eNOS) uncoupling, decreasing NO production and increasing vascular resistance through persistent vasoconstriction and SMC proliferation. C/EBP-homologous protein further inhibits eNOS, interfering with endothelial function. UPR-induced NF-κB activity regulates inflammatory processes in lung tissue and contributes to pulmonary vascular remodeling. Conversely, UPR-activated nuclear factor erythroid 2-related factor 2-mediated antioxidant signaling through heme oxygenase 1 attenuates inflammatory cytokine levels and protects against vascular SMC proliferation. A mutation in the bone morphogenic protein type 2 receptor (BMPR2) gene causes misfolded BMPR2 protein accumulation in the ER, implicating the UPR in familial pulmonary arterial hypertension pathogenesis. Altogether, there is substantial evidence that redox and inflammatory signaling associated with UPR activation is critical in PH pathogenesis.

Effect of irradiation on the expression of E-cadherin and β-catenin in early and late radiation sequelae of the urinary bladder and its modulation by NF-κB inhibitor thalidomide

Purpose

In a previous study we have shown in a mouse model that administration of nuclear factor-kappa B (NF-κB) inhibitor thalidomide has promising therapeutic effects on early radiation cystitis (ERC) and late radiation sequelae (LRS) of the urinary bladder. The aim of this study was to evaluate in the same mice the effect of thalidomide on adherens junction (AJ) proteins in ERC and LRS.

Methods

Urothelial expressions of E‑cadherin and β‑catenin were assessed by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) bladder specimens over 360 days post single-dose irradiation on day 0. First, the effect of irradiation on AJ expression and then effects of thalidomide on irradiation-induced AJ alterations were assessed using three different treatment times.

Results

Irradiation provoked a biphasic upregulation of E‑cadherin and β‑catenin in the early phase. After a mild decrease of E‑cadherin and a pronounced decrease of β‑catenin at the end of the early phase, both increased again in the late phase. Early administration of thalidomide (day 1–15) resulted in a steeper rise in the first days, an extended and increased expression at the end of the early phase and a higher expression of β‑catenin alone at the beginning of the late phase.

Conclusion

Upregulation of AJ proteins is an attempt to compensate irradiation-induced impairment of urothelial barrier function. Early administration of thalidomide improves these compensatory mechanisms by inhibiting NF-κB signaling and its interfering effects.

Transcriptional repression of NFKBIA triggers constitutive IKK- and proteasome-independent p65/RelA activation in senescence

The IκB kinase (IKK)‐NF‐κB pathway is activated as part of the DNA damage response and controls both inflammation and resistance to apoptosis. How these distinct functions are achieved remained unknown. We demonstrate here that DNA double‐strand breaks elicit two subsequent phases of NF‐κB activation in vivo and in vitro, which are mechanistically and functionally distinct. RNA‐sequencing reveals that the first‐phase controls anti‐apoptotic gene expression, while the second drives expression of senescence‐associated secretory phenotype (SASP) genes. The rapidly activated first phase is driven by the ATM‐PARP1‐TRAF6‐IKK cascade, which triggers proteasomal destruction of inhibitory IκBα, and is terminated through IκBα re‐expression from the NFKBIA gene. The second phase, which is activated days later in senescent cells, is on the other hand independent of IKK and the proteasome. An altered phosphorylation status of NF‐κB family member p65/RelA, in part mediated by GSK3β, results in transcriptional silencing of NFKBIA and IKK‐independent, constitutive activation of NF‐κB in senescence. Collectively, our study reveals a novel physiological mechanism of NF‐κB activation with important implications for genotoxic cancer treatment.

The Fire Within: NF-κB Involvement in Non-Small Cell Lung Cancer

Thirty-four years since its discovery, NF-κB remains a transcription factor with great potential for cancer therapy. However, NF-κB-targeted therapies have yet to find a way to be clinically translatable. Here, we focus exclusively on the role of NF-κB in non-small cell lung cancer (NSCLC) and discuss its contributing effect on cancer hallmarks such as inflammation, proliferation, survival, apoptosis, angiogenesis, epithelial-mesenchymal transition, metastasis, stemness, metabolism, and therapy resistance. In addition, we present our current knowledge of the clinical significance of NF-κB and its involvement in the treatment of patients with NSCLC with chemotherapy, targeted therapies, and immunotherapy.

The role of Interleukin 1 receptor antagonist in mesenchymal stem cell-based tissue repair and regeneration

Interleukin (IL)-1 receptor antagonist (IL-1Ra), a naturally occurring antagonist of IL-1α/IL-1β signaling pathways, has been attributed to the immunosuppressive effects of mesenchymal stem cells (MSCs). MSCs, in IL-1Ra-dependent manner, suppressed production of IL-1β in dermal macrophages, induced their polarization in anti-inflammatory M2 phenotype, attenuated antigen-presenting properties of dendritic cells (DCs), and promoted expansion of immunosuppressive T regulatory cells in the skin, which resulted in enhanced repair of the nonhealing wounds. Reduced activation of inflammasome and suppressed production of IL-1β in macrophages were mainly responsible for beneficial effects of MSC-derived IL-1Ra in alleviation of acute lung injury, dry eye syndrome, and corneal injury. Through the production of IL-1Ra, MSCs reduced migration of DCs to the draining lymph nodes and attenuated generation of inflammatory Th1 and Th17 cells that resulted in alleviation of fulminant hepatitis and rheumatoid arthritis. MSCs, in IL-1Ra-dependent manner, reduced liver fibrosis by suppressing production of Type I collagen in hepatic stellate cells. IL-1Ra was, at least partially, responsible for enhanced proliferation of hepatocytes and chondrocytes in MSC-treated animals with partial hepatectomy and osteoarthritis. Despite of these beneficial effects, IL-1Ra-dependent inhibition of IL-1α/IL-1β-signaling significantly increased risk of infections. Therefore, future experimental and clinical studies should delineate potential side effects of MSC-derived IL-1Ra before IL-1Ra-overexpressing MSCs could be used as a potentially new therapeutic agent for the treatment of acute and chronic inflammatory diseases.

TRIP6 regulates the proliferation, migration, invasion and apoptosis of osteosarcoma cells by activating the NF-κB signaling pathway

Thyroid hormone receptor-interacting protein 6 (TRIP6), a member of the zyxin family of Lin-Isl-Mec (LIM) proteins, is an adaptor protein primarily expressed in epithelial cells. TRIP6 can regulate a variety of cellular responses, such as actin cytoskeletal reorganization and cell adhesion. However, to the best of our knowledge, the role of TRIP6 in osteosarcoma (Os) has not been previously reported. Therefore, the present study investigated the role of TRIP6 in the occurrence and development of Os, and the potential of utilizing TRIP6 as a therapeutic target in Os. The present results suggested that the expression levels of TRIP6 were significantly increased in Os cells and clinical tissue specimens compared with normal osteoblasts and adjacent non-tumor tissue. Moreover, the present results suggested that overexpressing TRIP6 significantly increased proliferation, migration and invasion, while inhibiting apoptosis in Os cells. However, silencing TRIP6 decreased proliferation, migration and invasion, while activating apoptosis in Os cells. The present results suggested that overexpression of TRIP6 increased NF-κB activation by decreasing the protein expression levels of inhibitor of κBα, and increasing total and phosphorylated P65 levels. The present results indicated that TRIP6 silencing decreased NF-κB activation. Collectively, the present results suggested that TRIP6 may play a role in promoting Os cell proliferation, migration and invasion, while inhibiting cell apoptosis. Furthermore, TRIP6 may be utilized as a novel prognostic biomarker and therapeutic target in Os.

Translational Aspects of Nuclear Factor-Kappa B and Its Modulation by Thalidomide on Early and Late Radiation Sequelae in Urinary Bladder Dysfunction

PURPOSE

This preclinical study aimed to investigate the role of nuclear factor (NF)-κB in early and late radiogenic sequelae of urinary bladder dysfunction in mice. Thalidomide was applied either during the early or late response phase to determine potential effects of NF-κB inhibition on functional bladder impairment.

METHODS AND MATERIALS

After pelvic irradiation on day 0, female C3H/Neu mice were observed over a period of 360 days and radiation response was evaluated for alterations in bladder functionality and NF-κB activation. Functionality was determined in graded dose experiments (14-24 Gy) and assessed by micturition frequency analysis and transurethral cystotonometry to reveal alterations in voiding and volume. The induction of the NF-κB proteins p50 and p65 was evaluated by immunohistochemistry in response to a single dose of 23 Gy (ED₉₀). Thalidomide (100 mg/kg/d) was applied intraperitoneally in 3 treatment groups: daily from day 1 to 15, daily from day 16 to 30, and in 2-day-intervals from day 150 to 180.

RESULTS

Immunohistochemical analysis showed a biphasic activation of p50 and p65 during the early radiation cystitis phase (day 1-30). After a transient decrease, p50, but not p65, was reactivated permanently leading to increased levels, which suggests an occurrence of chronic inflammation correlated with functional impairment. Both early thalidomide treatments reduced NF-κB activation and shifted the ED₅₀ value for early radiation cystitis and late radiation sequelae to higher doses.

CONCLUSIONS

These data clearly demonstrate the involvement of NF-κB signaling in the pathogenesis of radiation-induced urinary bladder dysfunction. Additionally, this study emphasizes that biological targeting of early radiogenic processes has enormous effect on chronic symptoms. The late administration of thalidomide showed no significant effect on functionality.

Suppressive effects of dehydrocostus lactone on the toll-like receptor signaling pathways

Toll-like receptors (TLRs) are a group of pattern-recognition receptors (PRRs) that are at the core of innate and adaptive immune responses. TLRs activation triggers the activation of two downstream signaling pathways, the myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-β (TRIF)-dependent pathways. To evaluate the therapeutic potential of DHL, a natural sesquiterpene lactone derived from Inulahelenium L. and Saussurea lappa, we examined its effect on signal transduction via the TLR signaling pathways. DHL inhibited the activation of nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3), the representative transcription factors involved in the inflammatory response, induced by TLR agonists, as well as the expression of cyclooxygenase-2 and interferon inducible protein-10. DHL also inhibited the activation of NF-κB and IRF3 induced by the overexpression of downstream signaling components of the TLRs signaling pathways. All results suggest that DHL might become a new therapeutic drug for a variety of inflammatory diseases.

Newly Defined ATP-Binding Cassette Subfamily B Member 5 Positive Dermal Mesenchymal Stem Cells Promote Healing of Chronic Iron-Overload Wounds via Secretion of Interleukin-1 Receptor Antagonist

In this study, we report the beneficial effects of a newly identified dermal cell subpopulation expressing the ATP-binding cassette subfamily B member 5 (ABCB5) for the therapy of nonhealing wounds. Local administration of dermal ABCB5+ -derived mesenchymal stem cells (MSCs) attenuated macrophage-dominated inflammation and thereby accelerated healing of full-thickness excisional wounds in the iron-overload mouse model mimicking the nonhealing state of human venous leg ulcers. The observed beneficial effects were due to interleukin-1 receptor antagonist (IL-1RA) secreted by ABCB5+ -derived MSCs, which dampened inflammation and shifted the prevalence of unrestrained proinflammatory M1 macrophages toward repair promoting anti-inflammatory M2 macrophages at the wound site. The beneficial anti-inflammatory effect of IL-1RA released from ABCB5+ -derived MSCs on human wound macrophages was conserved in humanized NOD-scid IL2rγ null mice. In conclusion, human dermal ABCB5+ cells represent a novel, easily accessible, and marker-enriched source of MSCs, which holds substantial promise to successfully treat chronic nonhealing wounds in humans. Stem Cells 2019;37:1057-1074.

Transcriptomic analysis of small intestinal mucosa from porcine epidemic diarrhea virus infected piglets

Caused by porcine epidemic diarrhea virus (PEDV), porcine epidemic diarrhea (PED) is an acute infectious disease which causes damage to the intestine including intestinal villus atrophy and shedding, leading to serious economic losses to the pig industry worldwide. In order to obtain detailed information about the pathogenesis and host immune response in a PEDV-infected host for first In vivo study we used high-throughput sequencing to analyze the gene expression differences of the small intestinal mucosa after infection with PEDV. Transcripts obtained were over 65,525,000 clean reads after reassembly were 22,605 genes detected, of which 22,248 were known genes and 371 new genes were predicted. Moreover, 3168 genes expression was up-regulated and 3876 genes down-regulated. (Gene Ontology) GO annotation and functional enrichment analysis indicated that all of the DEGs (differentially expressed genes) were annotated into biological process, cellular component and molecular function. Most of these unigenes are annotated in cellular processes, the cell and binding. KEGG analysis of the DEGs showed that a total of 7044 DEGs unigenes were annotated into 323 pathways classified into 6 main categories. Most of these unigenes are annotated were related to immune system response to the infectious diseases pathways. In addition, 20 DEGs were verified by quantitative real-time PCR. As the first, in vivo, RNAseq analysis of piglets and PEDV infection, our study provides knowledge about the transcriptomics of intestinal mucosa in PEDV-infected piglets, from which a complex molecular pathways and pathogenesis-related biological processes are involved in PEDV interaction with piglet intestinal mucosa.

A Novel Monoallelic Nonsense Mutation in the NFKB2 Gene Does Not Cause a Clinical Manifestation

NF-κB signaling, acting through NFKB1 dependent canonical and NFKB2 dependent non-canonical pathways plays a critical role in inflammatory and immune responses. Recent studies have associated mutations in these two genes with a common variable immunodeficiency (CVID). While evaluating a female patient seeking a diagnosis explaining her recurrent infections, we found a novel heterozygous c.1831C > T (p.Arg611^∗) nonsense mutation in the NFKB2 gene which introduces a Stop codon in the ankyrin repeat domain of p100. Whole exome sequencing (WES) analysis, followed by Sanger sequencing, identified this previously unknown mutation in two other family members. Penetrance of the c.1831C > T variant was assessed by flow-cytometry and protein expression in peripheral blood mononuclear cells (PBMC); whereas, activation of the NF-κB2 signaling pathway was examined through immunoblotting and real-time PCR. Heterozygous c.1831C > T variant led to the expansion of lymphocyte B subpopulations with concomitant reduction of plasmablasts, low IgG levels, and accumulation of p52 in PBMC. On the other hand, tested subjects had normal levels of IgM, IgA, IgE and no impairment in lymphocytes proliferation. Although evaluated patients did not fulfill all clinical features of CVID, their health should be monitored in the future for possible late manifestation of the disease. In conclusion, we showed that NFKB2 haplodeficiency caused by c.1831C > T nonsense mutation is asymptomatic, possibly due to the compensatory mechanisms and allele redundancy.

Impact of intracellular ionic strength on dimer binding in the NF-kB Inducing kinase

Improper signaling of the nuclear factor-κB (NF-κB) pathway plays a critical role in many inflammatory disease states including cancer, stroke, and viral infections. Although the signaling pathways are known, how these molecular mechanisms respond to changes in the intracellular microenvironment such as pH, ionic strength, and temperature, remains elusive. Molecular dynamics simulations were employed to differentiate the structural dynamics of the NF-κB Inducing Kinase (NIK), a protein kinase responsible for invoking the non-canonical NF-κB pathway, in its native and mutant form, and in the absence and presence of salt concentration in efforts to probe whether changes in the ionic environment stabilize or destabilize the NIK dimer. Analyses of structure-activity and conformational-activity relationships indicate that the protein-protein interactions are sensitive to changes in the ionic strength. Ligand binding pockets as well as regions between the oligomer interface either compress or expand, affecting both local and distal intermolecular interactions that result in stabilization or destabilization in the protein assembly.

Genetic variations in NF-κB were associated with the susceptibility to hepatitis C virus infection among Chinese high-risk population

Polymorphisms within NF-κB pathway genes may be linked to hepatitis C virus (HCV) infection susceptibility and outcomes. We investigated the associations between single nucleotide polymorphisms (SNPs) in NF-κB and the susceptibility as well as resolution of HCV infection. A Chinese population, including 1125 uninfected control cases, 558 cases with spontaneous viral clearance and 898 cases with persistent HCV infection, was genotyped for four SNPs (rs11820062, rs230530, rs1056890 and rs3774963) using a TaqMan assay. Our logistic analyses indicate that the subjects carrying RelA rs11820062 A allele had a significantly increased risk of HCV susceptibility (P Bonferroni  < 0.003125 in a dominant or additive model). In stratified analysis, the increased risk associated with rs11820062 A allele on HCV susceptibility remained in some case subgroups. This study demonstrates that a genetic variant involved in the NF-κB pathway gene (rs11820062 A allele) is associated with an increased HCV susceptibility within a high-risk Chinese population.

Differential gene modulation of pattern-recognition receptor TLR and RIG-I-like and downstream mediators on intestinal mucosa of pigs infected with PEDV non S-INDEL and PEDV S-INDEL strains

Porcine epidemic diarrhea virus (PEDV) strains can be divided into non-S-INDEL and S-INDEL strains. PEDV pathogenesis is strain-specific, and studies in neonatal pigs have demonstrated that the PEDV non-S-INDEL strains are more pathogenic than the PEDV S-INDEL strains. RNA viruses, including PEDV, can interact with a large number of pattern recognition receptors (PRRs) in the intestinal mucosa, including toll-like receptors (TLRs) and RIG-I-like receptors (RLRs). We investigated the differential gene modulation of TLRs, RIG-I, and downstream mediators on the intestinal mucosa of neonatal pigs infected with PEDV S-INDEL and non-S-INDEL strains. Ten five-day-old piglets were inoculated orally with 10 ml of 10⁴ TCDI₅₀/ml of either PEDV non-S-INDEL or S-INDEL strains. PEDV S-INDEL infection induced pro-inflammatory cytokines through the non-canonical NF-κB signaling pathway by activating RIG-I. In contrast, PEDV non-S-INDEL infection suppressed the induction of pro-inflammatory cytokines and type 1 interferon production by down-regulation of TLRs and downstream signaling molecules.

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Differential gene modulation of TLR and RIG-I-like receptors and downstream mediators.

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PEDV S-INDEL induces pro-inflammatory cytokines through non-canonical NF-κB signaling pathway.

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PEDV S-INDEL pro-inflammatory cytokines activation is RIG-I dependent.

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PEDV non-S-INDEL suppresses the induction of pro-inflammatory cytokines and type 1 interferon.

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PEDV non-S-INDEL effect is mediated by down-regulation of TLRs and its downstream-signaling molecules.

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PEDV S-INDEL and PEDV non-S-INDEL cause differential modulation on innate immune response pathways.

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Differential modulation could be translated into differences in pathogenesis and clinical outcomes.

Enhanced IgG1 production by overexpression of nuclear factor kappa B inhibitor zeta (NFKBIZ) in Chinese hamster ovary cells

Several engineering strategies have been employed to improve the production of therapeutic recombinant proteins in Chinese hamster ovary (CHO) cell lines. We have focused on unfolded protein response-based engineering and reported that ATF4 overexpression increases protein production. In this study, transcriptome analysis of ATF4-overexpressed CHO cells was performed using high-coverage expression profiling, to search for another key factor contributing to recombinant protein production. We observed the upregulated expression of transcription factor, nuclear factor (NF)-kappa-B inhibitor zeta (NFKBIZ or Iκbζ), in ATF4-overexpressed cells. A total of 1917 bp of CHO NFKBIZ cDNA was cloned, and two stable cell lines overexpressing NFKBIZ were constructed. We investigated the effects of NFKBIZ on IgG1 production in CHO cells. Although the two stable cell lines, NFKBIZ-A and -B, had the opposite phenotypes in cell growth, the specific IgG1 production rate of both cell lines was enhanced by 1.2-1.4-fold. In the NFKBIZ-A cell line, the synergistic effect between enhanced viable cell density and improved specific IgG1 production rate brought about a large increase in the final IgG1 titer. Luciferase-based NF-κB signaling assay results suggest that altered p50/p50 signaling seems to be due to the opposite phenotypes in cell growth. No difference was observed in the translational levels and intracellular assembly states of IgG1 between mock and two NFKBIZ cell lines, indicating that the secretion machinery of correctly folded IgG1 was enhanced in NFKBIZ-overexpressing cell lines.

Involvement of NF-κB in regulation of Actinobacillus pleuropneumoniae exotoxin ApxI-induced proinflammatory cytokine production in porcine alveolar macrophages

Actinobacillus pleuropneumoniae is a crucial respiratory pathogen that causes fibrinous, hemorrhagic, necrotizing pleuropneumonia in pigs. A. pleuropneumoniae exotoxins (ApxI to IV) are the major virulence factors contributing to A. pleuropneumoniae pathogenesis. Previously, we demonstrated that ApxI induces the expression of proinflammatory cytokines in porcine alveolar macrophages (PAMs) via the mitogen-activated protein kinases (MAPKs) p38 and cJun NH2-terminal kinase (JNK). Nonetheless, the role of nuclear factor (NF)-κB-a transcription factor widely implicated in immune and inflammatory responses-in ApxI-elicited cytokine production has yet to be defined. In the present study, we examined the involvement of NF-κB in ApxI-elicited production of interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in PAMs and investigated the correlation between NF-κB and MAPK (p38 and JNK) pathways in this event. The results of Western blot analysis, confocal microscopy, and a DNA binding activity assay revealed that the classical NF-κB pathway was activated by ApxI, as evidenced by the decreased levels of IκB and subsequent NF-κB translocation and activation in ApxI-stimulated PAMs. Moreover, the blocking of ApxI-induced NF-κB activation significantly attenuated the levels of mRNA and protein secretion of IL-1β, IL-8, and TNF-α in PAMs. Notably, the attenuation of JNK activation by a specific inhibitor (SP600125) reduced ApxI-induced NF-κB activation, whereas a p38 blocker (SB203580) had no effect on the NF-κB pathway. Further examination revealed that the level of phosphorylation at serine 536 on the NF-κB p65 subunit was dependent on JNK activity. Collectively, this study, for the first time, demonstrates a pivotal role of NF-κB in ApxI-induced IL-1β, IL-8, and TNF-α production; JNK, but not p38, may positively affect the activation of the classical NF-κB pathway.

Progranulin deficiency induces overactivation of WNT5A expression via TNF-α/NF-κB pathway in peripheral cells from frontotemporal dementia-linked granulin mutation carriers

BACKGROUND

Loss-of-function progranulin gene (GRN) mutations have been identified as the major cause of frontotemporal lobar degeneration with transactive response (TAR) DNA-binding protein 43 (TDP-43) pathology (frontotemporal lobar degeneration [FTLD]-TDP); however, little is known about the association between progranulin (PGRN) deficiency and neuronal loss in individuals with FTLD-TDP. Previously we reported enhanced proliferative activity associated with the activation of WNT5A/CDK6/pRb signalling in PGRN-deficient cells. The objective of this work was to elucidate the association between PGRN deficiency, WNT5A signalling and cell proliferation in immortalized lymphoblasts from carriers of the c.709-1G > A GRN mutation (asymptomatic and FTLD-TDP).

METHODS

We assessed cell proliferation in carriers of the c.709-1G > A GRN gene mutation and controls without GRN mutation and without sign of neurologic degeneration by cell counting or using an MTT assay. We used a luciferase assay to measure the nuclear factor-κ (NF-κ) activity. We evaluated messenger RNA levels using quantitative real-time polymerase chain reaction and protein levels by immunoblotting. Co-immunoprecipitation was used to analyze the interaction between PGRN and its receptors.

RESULTS

We enrolled 19 carriers of the GRN gene mutation and 10 controls in this study. The PGRN-deficient cells showed increased expression of WNT5A due to NF-κB signalling overactivation. We observed a competition between PGRN and tumour necrosis factor-α (TNF-α) for binding both TNF receptors (TNFR) I and II. Blocking NF-κB signalling using wedelolactone or specific antibodies against TNFRs inhibited WNT5A overexpression and proliferation of PGRN-deficient cells. Conversely, the activation of NF-κB signalling by TNF-α increased WNT5A-dependent proliferation of control cells.

LIMITATIONS

All cell lines were derived from individuals harboring the same splicing GRN mutation. Nevertheless, most of the known GRN mutations lead to haploinsufficiency of the protein.

CONCLUSION

Our results revealed an important role of NF-κB signalling in PGRN-associated FTLD-TDP and confirm that PGRN can bind to TNF-α receptors regulating the expression of WNT5A, suggesting novel targets for treatment of FTLD-TDP linked to GRN mutations.

Structure-activity relationships of benzhydrol derivatives based on 1'-acetoxychavicol acetate (ACA) and their inhibitory activities on multiple myeloma cell growth via inactivation of the NF-κB pathway

1'-Acetoxychavicol acetate (ACA), which was isolated from the rhizomes of Zingiberaceae, exhibits various biological actions, including anti-inflammatory, anti-human immunodeficiency virus (HIV), and anti-cancer activities. ACA represents an attractive candidate for the treatment of many cancers. We herein examined the structure-activity relationships of ACA derivatives based on the benzhydrol skeleton in human leukemia cells (HL-60). Our results revealed that the ACA derivatives synthesized (ACA, 1, and 18) had inhibitory effects on the growth of multiple myeloma cells (IM-9 cells) by inactivating the NF-κB pathway.

NF-kB as a key player in regulation of cellular radiation responses and identification of radiation countermeasures

Nuclear factor (NF)-κB is a transcription factor that plays significant role in immunity, cellular survival and inhibition of apoptosis, through the induction of genetic networks. Depending on the stimulus and the cell type, the members of NF-κB related family (RelA, c-Rel, RelB, p50, and p52), forms different combinations of homo and hetero-dimers. The activated complexes (Es) translocate into the nucleus and bind to the 10bp κB site of promoter region of target genes in stimulus specific manner. In response to radiation, NF-κB is known to reduce cell death by promoting the expression of anti-apoptotic proteins and activation of cellular antioxidant defense system. Constitutive activation of NF-κB associated genes in tumour cells are known to enhance radiation resistance, whereas deletion in mice results in hypersensitivity to IR-induced GI damage. NF-κB is also known to regulate the production of a wide variety of cytokines and chemokines, which contribute in enhancing cell proliferation and tissue regeneration in various organs, such as the GI crypts stem cells, bone marrow etc., following exposure to IR. Several other cytokines are also known to exert potent pro-inflammatory effects that may contribute to the increase of tissue damage following exposure to ionizing radiation. Till date there are a series of molecules or group of compounds that have been evaluated for their radio-protective potential, and very few have reached clinical trials. The failure or less success of identified agents in humans could be due to their reduced radiation protection efficacy. In this review we have considered activation of NF-κB as a potential marker in screening of radiation countermeasure agents (RCAs) and cellular radiation responses. Moreover, we have also focused on associated mechanisms of activation of NF-κB signaling and their specified family member activation with respect to stimuli. Furthermore, we have categorized their regulated gene expressions and their function in radiation response or modulation. In addition, we have discussed some recently developed radiation countermeasures in relation to NF-κB activation

Tat predominantly associates with host promoter elements in HIV-1-infected T-cells - regulatory basis of transcriptional repression of c-Rel

HIV-1 Tat is a multifunctional regulatory protein that, in addition to its primary function of transactivating viral transcription, also tends to modulate cellular gene expression, for which the molecular mechanism remains to be clarified. We have reported earlier nuclear factor kappa B (NFκB) enhancer binding activity of Tat and proposed this DNA binding activity as a possible molecular basis for Tat-mediated regulation of cellular gene expression in infected cells. In the present study, we analyzed the genome-wide occupancy of Tat protein on host cell chromatin in HIV-1-infected T-cells to investigate a potential role of Tat on cellular gene expression. The results obtained identify a spectrum of binding sites of Tat protein on the chromatin and reveal that Tat is also recruited on a number of cellular gene promoters in HIV-1-infected T-cells, indicating its possible involvement in the regulation of gene expression of such cellular genes. Tat was identified as a repressor of one such validated gene, c-Rel, because it downregulates the expression of c-Rel in both Tat expressing and HIV-1-infected T-cells. The results also show that Tat downregulates c-Rel promoter activity by interacting with specific NFκB sites on the c-Rel promoter, thus providing a molecular basis of Tat-mediated regulation of cellular gene expression. Thus, in the present study, we have not only identified recruitment sites of Tat on the chromatin in HIV-1-infected T-cells, but also report for the first time that c-Rel is downregulated in HIV-1-infected cells specifically by interaction of Tat with NFκB binding sites on the promoter.

Notch and hedgehog signaling cooperate to maintain self-renewal of human embryonic stem cells exposed to low oxygen concentration

BACKGROUND AND OBJECTIVES

Expansion and maintenance of human embryonic stem cells (hESCs) in undifferentiated state is influenced by complex signals in the microenvironment, including those contingent upon oxygen availability. Responses mediated by Notch and Hedgehog (Hh) have essential role in the growth and maintenance of hESCs, therefore this study examined their effect on the self-renewal of hESCs exposed to low oxygen.

METHODS AND RESULTS

Using potent antagonists γ-secretase inhibitor and cyclopamine, we inhibited Notch and Hh pathways, respectively, in the CLS1 hESC line expanded continuously in a hypoxic atmosphere of 5% oxygen. Immunohistochemical staining and protein assays revealed loss of Oct4 and gain of stage-specific embryonic antigen 1 (SSEA1) markers in the inhibited cells. Semiquantitative real-time RT-PCR, and bromodeoxyuridine and thymidine incorporation assays demonstrated low Oct4 and Nanog mRNA expression, and decreased DNA synthesis, respectively, resulting from the block of each of the pathways. The loss increased significantly with co-inhibition of both pathways. Importantly, Notch and Hh downstream targets, including Hes1, Hey1, GIi1, and Ptc1, were surprisingly suppressed not only by the pathway-specific but also the unrelated inhibitor.

CONCLUSIONS

These findings demonstrate complementary effect of Notch and Hh signaling in hypoxia enhanced maintenance of hESCs.

Cyclin-dependent kinase 6 is a chromatin-bound cofactor for NF-κB-dependent gene expression

Given the intimate link between inflammation and dysregulated cell proliferation in cancer, we investigated cytokine-triggered gene expression in different cell cycle stages. Transcriptome analysis revealed that G1 release through cyclin-dependent kinase 6 (CDK6) and CDK4 primes and cooperates with the cytokine-driven gene response. CDK6 physically and functionally interacts with the NF-κB subunit p65 in the nucleus and is found at promoters of many transcriptionally active NF-κB target genes. CDK6 recruitment to distinct chromatin regions of inflammatory genes was essential for proper loading of p65 to its cognate binding sites and for the function of p65 coactivators, such as TRIP6. Furthermore, cytokine-inducible nuclear translocation and chromatin association of CDK6 depends on the kinase activity of TAK1 and p38. These results have widespread biological implications, as aberrant CDK6 expression or activation that is frequently observed in human tumors modulates NF-κB to shape the cytokine and chemokine repertoires in chronic inflammation and cancer.

Suppression of TRIF-dependent signaling pathway of toll-like receptors by (E)-1-(2-(2-nitrovinyl)phenyl)pyrrolidine

Toll-like receptors (TLRs) play an important role in the recognition of microbial pathogens and induce innate immune responses. The recognition of microbial components by TLRs triggers the activation of myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-β (TRIF)-dependent downstream signaling pathways. Previously, we synthesized (E)-1-(2-(2-nitrovinyl)phenyl)pyrrolidine (NVPP), which contains a nitrovinyl-phenyl and pyrrolidine. To evaluate the therapeutic potential of NVPP, its effect on signal transduction via the TRIF-dependent pathway of TLRs induced by lipopolysaccharide (LPS) or polyinosinic-polycytidylic acid (poly[I:C]) was examined. NVPP inhibited LPS or poly[I:C]-induced activation of nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3), and the phosphorylation of IRF3, as well as inhibiting the activation of interferon-inducible genes such as interferon inducible protein-10 (IP-10). These results suggest that NVPP can modulate TRIF-dependent signaling pathways of TLRs, potentially resulting in effective therapeutics for chronic inflammatory diseases.

RelB: an outlier in leukocyte biology

RelB is one of the more unusual members of the NF-κB family. This family, arguably the best known group of transcription regulators, regulates an astonishing array of cell types and biological processes. This includes regulation of cell growth, differentiation and death by apoptosis, and the development and function of the innate and adaptive-immune system. RelB is best known for its roles in lymphoid development, DC biology, and noncanonical signaling. Within the last few years, however, surprising functions of RelB have emerged. The N-terminal leucine zipper motif of RelB, a motif unique among the NF-κB family, may associate with more diverse DNA sequences than other NF-κB members. RelB is capable of direct binding to the AhR that supports the xenobiotic-detoxifying pathway. RelB can regulate the circadian rhythm by directly binding to the BMAL partner of CLOCK. Finally, RelB also couples with bioenergy NAD(+) sensor SIRT1 to integrate acute inflammation with changes in metabolism and mitochondrial bioenergetics. In this review, we will explore these unique aspects of RelB, specifically with regard to its role in immunity.

Porcine epidemic diarrhea virus N protein prolongs S-phase cell cycle, induces endoplasmic reticulum stress, and up-regulates interleukin-8 expression

Porcine epidemic diarrhea (PED) is an acute and highly contagious enteric disease of swine caused by porcine epidemic diarrhea virus (PEDV). The porcine intestinal epithelial cell is the PEDV target cell. In this study, we established a porcine intestinal epithelial cell (IEC) line which can stably express PEDV N protein. We also investigate the subcellular localization and function of PEDV N protein by examining its effects on cell growth, cycle progression, interleukin-8 (IL-8) expression, and survival. The results show that the PEDV N protein localizes in the endoplasmic reticulum (ER), inhibits the IEC growth and prolongs S-phase cell cycle. The S-phase is prolonged which is associated with a decrease of cyclin A transcription level and an increase of cyclin A degradation. The IEC expressing PEDV N protein can express higher levels of IL-8 than control cells. Further studies show that PEDV N protein induces ER stress and activates NF-κB, which is responsible for the up-regulation of IL-8 and Bcl-2 expression. This is the first report to demonstrate that PEDV N protein can induce cell cycle prolongation at the S-phase, ER stress and up-regulation interleukin-8 expression. These findings provide novel information on the function of the PEDV N protein and are likely to be very useful in understanding the molecular mechanisms responsible for PEDV pathogenesis.

Porcine epidemic diarrhea virus E protein causes endoplasmic reticulum stress and up-regulates interleukin-8 expression

Background

Porcine epidemic diarrhea virus (PEDV) is an important pathogen in swine and is responsible for substantial economic losses. Previous studies suggest that the PEDV E protein plays an important role in the viral assembly process. However, the subcellular localization and other functions of PEDV E protein still require more research.

Methods

The subcellular localization and function of PEDV E protein were investigated by examining its effects on cell growth, cell cycle progression, interleukin-8 (IL-8) expression and cell survival.

Results

The results show that plenty of PEDV E protein is localized in the ER, with small quantities localized in the nucleus. The PEDV E protein has no effect on the intestinal epithelial cells (IEC) growth, cell cycle and cyclin A expression. The cells expressing PEDV E protein express higher levels of IL-8 than control cells. Further studies show that PEDV E protein induced endoplasmic reticulum (ER) stress and activated NF-κB which is responsible for the up-regulation of IL-8 and Bcl-2 expression.

Conclusions

This study shows that the PEDV E protein is localized in the ER and the nucleus and it can cause ER stress. The PEDV E protein had no effect on the IEC growth and cell cycle. In addition, the PEDV E protein is able to up-regulate IL-8 and Bcl-2 expression.

Cyclin-dependent kinase 6 phosphorylates NF-κB P65 at serine 536 and contributes to the regulation of inflammatory gene expression

Nuclear factor kappa-B (NF-κB) activates multiple genes with overlapping roles in cell proliferation, inflammation and cancer. Using an unbiased approach we identified human CDK6 as a novel kinase phosphorylating NF-κB p65 at serine 536. Purified and reconstituted CDK6/cyclin complexes phosphorylated p65 in vitro and in transfected cells. The physiological role of CDK6 for basal as well as cytokine-induced p65 phosphorylation or NF-κB activation was revealed upon RNAi-mediated suppression of CDK6. Inhibition of CDK6 catalytic activity by PD332991 suppressed activation of NF-κB and TNF-induced gene expression. In complex with a constitutively active viral cyclin CDK6 stimulated NF-κB p65-mediated transcription in a target gene specific manner and this effect was partially dependent on its ability to phosphorylate p65 at serine 536. Tumor formation in thymi and spleens of v-cyclin transgenic mice correlated with increased levels of p65 Ser536 phosphorylation, increased expression of CDK6 and upregulaton of the NF-κB target cyclin D3. These results suggest that aberrant CDK6 expression or activation that is frequently observed in human tumors can contribute through NF-κB to chronic inflammation and neoplasia.

The coactivator role of histone deacetylase 3 in IL-1-signaling involves deacetylation of p65 NF-κB

Histone deacetylase (HDAC) 3, as a cofactor in co-repressor complexes containing silencing mediator for retinoid or thyroid-hormone receptors (SMRT) and nuclear receptor co-repressor (N-CoR), has been shown to repress gene transcription in a variety of contexts. Here, we reveal a novel role for HDAC3 as a positive regulator of IL-1-induced gene expression. Various experimental approaches involving RNAi-mediated knockdown, conditional gene deletion or small molecule inhibitors indicate a positive role of HDAC3 for transcription of the majority of IL-1-induced human or murine genes. This effect was independent from the gene regulatory effects mediated by the broad-spectrum HDAC inhibitor trichostatin A (TSA) and thus suggests IL-1-specific functions for HDAC3. The stimulatory function of HDAC3 for inflammatory gene expression involves a mechanism that uses binding to NF-κB p65 and its deacetylation at various lysines. NF-κB p65-deficient cells stably reconstituted to express acetylation mimicking forms of p65 (p65 K/Q) had largely lost their potential to stimulate IL-1-triggered gene expression, implying that the co-activating property of HDAC3 involves the removal of inhibitory NF-κB p65 acetylations at K122, 123, 314 and 315. These data describe a novel function for HDAC3 as a co-activator in inflammatory signaling pathways and help to explain the anti-inflammatory effects frequently observed for HDAC inhibitors in (pre)clinical use.

A conserved domain in the N-terminus is important for LEAFY dimerization and function in Arabidopsis thaliana

The floral meristem identity gene LEAFY (LFY) of Arabidopsis thaliana is essential for the formation of fertile flowers and has roles in the control of several aspects of floral development, which include phyllotaxy and organ number and identity. This gene encodes a land plant-specific transcription factor and regulates expression of a number of genes that include other floral meristem identity genes and floral homeotic genes. Although the LFY DNA-binding domain has a structure that resembles that of helix-turn-helix proteins, LFY and its orthologs represent a novel family of transcription factors that are characterized by a conserved N-terminus domain of unknown function and a C-terminus DNA-binding domain. Many transcription factors act as dimers. These dimers are essential for the biological activity of the proteins. We demonstrate that LFY forms homodimers or oligomers in solution. This association is mediated through the N-terminus conserved region of the LFY protein. Although mutant LFY proteins that cannot dimerize in solution can bind DNA, the binding is weaker than that of wild type LFY protein. LFY-LFY interactions mediated by the N-terminus domain are essential for the biological activity of this protein, as mutations that abolish the ability to self-associate cannot complement an lfy null allele. Our data indicate: (i) that LFY, and probably its orthologs in other plants, must act in complexes that contain at least two LFY molecules; and (ii) that the N-terminus is essential for stabilization of LFY complexes. This situation is integral to the ability of LFY to regulate gene expression.

Suppression of the TRIF-dependent signaling pathway of toll-like receptors by (E)-isopropyl 4-oxo-4-(2-oxopyrrolidin-1-yl)-2-butenoate

Toll-like receptors (TLRs) are pattern recognition receptors that recognize molecular structures derived from microbes and initiate innate immunity. TLRs have two downstream signaling pathways, the MyD88- and TRIF-dependent pathways. Dysregulated activation of TLRs is closely linked to increased risk of many chronic diseases. Previously, we synthesized fumaryl pyrrolidinone, (E)-isopropyl 4-oxo-4-(2-oxopyrrolidin-1- yl)-2-butenoate (IPOP), which contains a fumaric acid isopropyl ester and pyrrolidinone, and demonstrated that it inhibits the activation of nuclear factor kappa B by inhibiting the MyD88-dependent pathway of TLRs. However, the effect of IPOP on the TRIF-dependent pathway remains unknown. Here, we report the effect of IPOP on signal transduction via the TRIF-dependent pathway of TLRs. IPOP inhibited lipopolysaccharide- or polyinosinic-polycytidylic acid-induced interferon regulatory factor 3 activation, as well as interferon- inducible genes such as interferon inducible protein-10. These results suggest that IPOP can modulate the TRIF-dependent signaling pathway of TLRs, leading to decreased inflammatory gene expression.

Profile of NF-κBp(65/NFκBp50) among prostate specific antigen sera levels in prostatic pathologies

AIM

The aim of this work was to characterise the immunoexpression of NF-κB (p50/p65) in human prostatic pathologies and to study its profiles of activation among sera prostate specific antigen antigen (PSA) according the three groups: 0-4ng/mL, 4-20ng/mL and >20ng/mL.

PATIENTS AND METHODS

Twenty-four men with benign prostate hyperplasia (BPH); 19 men with prostate cancer (PC) and five men with normal prostates (NP). Immunohistochemical and western blot analysis was performed. Serum levels of PSA were assayed by immulite autoanalyser.

RESULTS

In BPH and PC samples, immunoexpressions were observed for NF-κBp65 and NF-κBp50; while in NP samples, only were detected NF-κBp50. PC samples showed immunoreactions to NF-κBp65 and NF-κBp50 more intense (respectively 24.18±0.67 and 28.23±2.01) than that observed in BPH samples (respectively18.46±2.04 and 18.66±1.59) with special localisation in the nucleus. Different profiles of NF-κBp65 immunoexpressions were observed and BPH patients with sera PSA levels between 0-4ng/mL presented a significant weak percentage compared to BPH patients with sera PSA levels between 4-20ng/mL and >20ng/mL. No immunoreactions to NF-κBp65 were observed in PC patients with sera PSA levels between 4-20ng/mL.

CONCLUSION

The sensibility of both NF-κB and PSA to inflammation allowed confirming the relationship between these two molecules and its involvement in prostatic diseases progression (inflammatory and neoplasic).

Modulation of Mucosal Immune Response, Tolerance, and Proliferation in Mice Colonized by the Mucin-Degrader Akkermansia muciniphila

Epithelial cells of the mammalian intestine are covered with a mucus layer that prevents direct contact with intestinal microbes but also constitutes a substrate for mucus-degrading bacteria. To study the effect of mucus degradation on the host response, germ-free mice were colonized with Akkermansia muciniphila. This anaerobic bacterium belonging to the Verrucomicrobia is specialized in the degradation of mucin, the glycoprotein present in mucus, and found in high numbers in the intestinal tract of human and other mammalian species. Efficient colonization of A. muciniphila was observed with highest numbers in the cecum, where most mucin is produced. In contrast, following colonization by Lactobacillus plantarum, a facultative anaerobe belonging to the Firmicutes that ferments carbohydrates, similar cell-numbers were found at all intestinal sites. Whereas A. muciniphila was located closely associated with the intestinal cells, L. plantarum was exclusively found in the lumen. The global transcriptional host response was determined in intestinal biopsies and revealed a consistent, site-specific, and unique modulation of about 750 genes in mice colonized by A. muciniphila and over 1500 genes after colonization by L. plantarum. Pathway reconstructions showed that colonization by A. muciniphila altered mucosal gene expression profiles toward increased expression of genes involved in immune responses and cell fate determination, while colonization by L. plantarum led to up-regulation of lipid metabolism. These indicate that the colonizers induce host responses that are specific per intestinal location. In conclusion, we propose that A. muciniphila modulates pathways involved in establishing homeostasis for basal metabolism and immune tolerance toward commensal microbiota.

Classical swine fever virus NS2 protein promotes interleukin-8 expression and inhibits MG132-induced apoptosis

Classical swine fever (CSF) caused by virulent strains of classical swine fever virus (CSFV) is a hemorrhagic disease of pigs and is characterized by disseminated intravascular coagulation, thrombocytopenia, and immunosuppression. Until now, the role of the NS2 protein produced by CSFV in the pathogenesis of CSF is not well understood. In this report, we investigated the function of CSFV NS2 by examining its effects on the pro-inflammatory CXC chemokine, interleukin-8 (IL-8) expression, and cell survival. Stable swine umbilical vein endothelial cell line (SUVEC) expressing CSFV NS2 were established and showed that CSFV NS2 expressing SUVEC cells express approximately 16-fold higher levels of IL-8 as compared to control vector GFP-expressing cells, GFP-E2 expressing cells, and untransfected cells. Further studies showed that CSFV NS2 induced endoplasmic reticulum stress and activated the nuclear transcription factor kappa B (NF-κB), which is responsible for the up-regulation of IL-8 and the anti-apoptotic protein, Bcl-2, expression. In addition, the GFPNS2-expressing SUVEC cells were resistant to MG132-induced apoptosis. This study suggested that CSFV NS2 plays an important role in the inflammatory response and in persistent CSFV infection. These findings provide novel information on the function of the poorly characterized CSFV NS2.

Interleukin-32α production is regulated by MyD88-dependent and independent pathways in IL-1β-stimulated human alveolar epithelial cells

Interleukin (IL)-32 is a recently described cytokine that appears to play a critical role in a variety of inflammatory diseases including chronic obstructive pulmonary disease (COPD). However, thus far, the regulation of IL-32 production has not been fully established. Here, we report on signaling pathways that regulate the production of IL-32α, the most abundant isoform, in the human alveolar epithelial cell line, A549. IL-32α was expressed and secreted by IL-1β. The IL-32 expression was attenuated by PP2 (a Src-family kinase [SFK] inhibitor), rottlerin (a protein kinase [PK] Cδ inhibitor), and LY294002 (a phosphatidylinositol 3-kinase [PI3K] inhibitor). Furthermore, the overexpression of Fgr rather than other SFKs upregulated IL-32α expression, while Fgr small interfering RNA (siRNA) transfection downregulated it. The suppression of Fgr with PP2 and Fgr siRNA inhibited activating phosphorylation of PKCδ and PI3K/Akt, but not IL-1 receptor-associated kinase (IRAK)1, a well-known MyD88-dependent signaling molecule, and Erk1/2, p38, and JNK. Rottlerin and PKCδ siRNA also inhibited expression of IL-32α and activation of PI3K/Akt, but not of IRAK1 and mitogen activation protein (MAP) kinases. MyD88 siRNA suppressed the expression of IL-32α and the phosphorylation of IRAK1, PI3K, and MAP kinases, but not of PKCδ. Of interest, both Fgr/PKCδ and MyD88-dependent signals regulated PI3K/Akt, suggesting that it is a crosstalk molecule. Among MyD88-dependent MAP kinases, only p38 regulated IL-32α expression and PI3K/Akt activation. With these results, we demonstrated that the expression and secretion of IL-32α are regulated by MyD88-dependent IRAK1/p38/PI3K and independent Fgr/PKCδ/PI3K pathways, and that Fgr and PKCδ are critical for the MyD88-independent IL-32α production.

Human mucosal in vivo transcriptome responses to three lactobacilli indicate how probiotics may modulate human cellular pathways

Probiotic bacteria, specific representatives of bacterial species that are a common part of the human microbiota, are proposed to deliver health benefits to the consumer by modulation of intestinal function through largely unknown molecular mechanisms. To explore in vivo mucosal responses of healthy adults to probiotics, we obtained transcriptomes in an intervention study after a double-blind placebo-controlled cross-over design. In the mucosa of the proximal small intestine of healthy volunteers, probiotic strains from the species Lactobacillus acidophilus, L. casei, and L. rhamnosus each induced differential gene-regulatory networks and pathways in the human mucosa. Comprehensive analyses revealed that these transcriptional networks regulate major basal mucosal processes and uncovered remarkable similarity to response profiles obtained for specific bioactive molecules and drugs. This study elucidates how intestinal mucosa of healthy humans perceives different probiotics and provides avenues for rationally designed tests of clinical applications.

TBK1-targeted suppression of TRIF-dependent signaling pathway of toll-like receptor 3 by auranofin

Toll-like receptors (TLRs) play an important role in induction of innate immune responses. The stimulation of TLRs by microbial components triggers two branches of downstream signaling pathways: myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-beta (TRIF)-dependent signaling pathways. Auranofin, a sulfur-containing gold compound (Au[I]), has been widely used for the treatment of rheumatoid arthritis. Since dysregulation of TLRs can lead to severe systemic inflammatory and joint destructive process in rheumatoid arthritis, auranofin-mediated modulation of TLR activation may have therapeutic potential against such diseases. Previously, we demonstrated that auranofin suppressed TLR4 signaling pathway by inhibiting TLR4 dimerization induced by LPS. Here, we examined the effect of auranofin on signal transduction via the TRIF-dependent pathway induced by a TLR3 agonist. Auranofin inhibited nuclear factor-kappaB and interferon (IFN) regulatory factor 3 (IRF3) activation induced by polyinosinic-polycytidylic acid (poly[I:C]). Auranofin inhibited poly[I:C]-induced phosphorylation of IRF3 as well as IFN-inducible genes such as IFN inducible protein-10. Furthermore, auranofin inhibited TBK1 kinase activity in vitro. All the results suggest that auranofin suppress TLR signaling at multiple steps.

Construction of a large scale integrated map of macrophage pathogen recognition and effector systems

Background

In an effort to better understand the molecular networks that underpin macrophage activation we have been assembling a map of relevant pathways. Manual curation of the published literature was carried out in order to define the components of these pathways and the interactions between them. This information has been assembled into a large integrated directional network and represented graphically using the modified Edinburgh Pathway Notation (mEPN) scheme.

Results

The diagram includes detailed views of the toll-like receptor (TLR) pathways, other pathogen recognition systems, NF-kappa-B, apoptosis, interferon signalling, MAP-kinase cascades, MHC antigen presentation and proteasome assembly, as well as selected views of the transcriptional networks they regulate. The integrated pathway includes a total of 496 unique proteins, the complexes formed between them and the processes in which they are involved. This produces a network of 2,170 nodes connected by 2,553 edges.

Conclusions

The pathway diagram is a navigable visual aid for displaying a consensus view of the pathway information available for these systems. It is also a valuable resource for computational modelling and aid in the interpretation of functional genomics data. We envisage that this work will be of value to those interested in macrophage biology and also contribute to the ongoing Systems Biology community effort to develop a standard notation scheme for the graphical representation of biological pathways.

Cross talk between stimulated NF-kappaB and the tumor suppressor p53

Nuclear factor-kappaB (NF-kappaB) and p53 critically determine cancer development and progression. Defining the cross talk between these transcription factors can expand our knowledge on molecular mechanisms of tumorigenesis. Here, we show that induction of replicational stress activates NF-kappaB p65 and triggers its interaction with p53 in the nucleus. Experiments with knockout cells show that p65 and p53 are both required for enhanced NF-kappaB activity during S-phase checkpoint activation involving ataxia-telangiectasia mutated and checkpoint kinase-1. Accordingly, the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) also triggers formation of a transcriptionally active complex containing nuclear p65 and p53 on kappaB response elements. Gene expression analyses revealed that, independent of NF-kappaB activation in the cytosol, TNF-induced NF-kappaB-directed gene expression relies on p53. Hence, p53 is unexpectedly necessary for NF-kappaB-mediated gene expression induced by atypical and classical stimuli. Remarkably, data from gain- and loss-of function approaches argue that anti-apoptotic NF-kappaB p65 activity is constitutively evoked by a p53 hot-spot mutant frequently found in tumors. Our observations suggest explanations for the outstanding question why p53 mutations rather than p53 deletions arise in tumors of various origins.

Divergent intracellular pathways regulate interleukin-1beta-induced miR-146a and miR-146b expression and chemokine release in human alveolar epithelial cells

We have previously reported that IL-beta-induced miR-146a and miR-146b expression negatively regulates IL-8 and RANTES release in human alveolar A549 epithelial cells. To determine the intracellular pathways that regulate this response, we demonstrate IL-1beta-induced activation of the nuclear factor (NF)-kappaB, extracellular regulated kinase (ERK)-1/2, c-jun N-terminal kinase (JNK)-1/2 and p38 mitogen activated kinase (MAP) kinase pathways. Subsequent pharmacological studies show that IL-1beta-induced miR-146a, IL-8 and RANTES production was regulated via NF-kappaB and JNK-1/2 whilst miR-146b expression was mediated via MEK-1/2 and JNK-1/2. These divergent intracellular pathways likely explain the differential expression and biological action of the miR-146 isoforms.

Phosphorylation of NF-kappaB p65 at Ser468 controls its COMMD1-dependent ubiquitination and target gene-specific proteasomal elimination

The nuclear factor-kappaB (NF-kappaB) transcription factor system is a crucial component that controls several important biological functions, thus raising the need for mechanisms that ensure the correct termination of its activity. Here, we identify a new phosphorylation/ubiquitination switch in the NF-kappaB network that controls the stability of the transactivating p65 subunit. Tumour necrosis factor-induced phosphorylation of p65 at Ser468 allows binding of COMMD1 and cullin 2, components of a multimeric ubiquitin ligase complex mediating p65 ubiquitination. Mutation of p65 at Ser468 largely prevents p65 ubiquitination and proteasomal degradation. Inducible p65 elimination is restricted to a subset of NF-kappaB target genes such as Icam1. Accordingly, chromatin immunoprecipitation experiments reveal the selective recruitment of Ser468-phosphorylated p65 and COMMD1 to the Icam1 promoter. Phosphorylation of p65 at Ser468 leads to ubiquitin/proteasome-dependent removal of chromatin-bound p65, thus contributing to the selective termination of NF-kappaB-dependent gene expression.

Autoregulatory feedback loops terminating the NF-kappaB response

After nuclear factor (NF)-kappaB activation, a complex network of negative feedback loops ensures that the termination of the NF-kappaB response occurs in a highly organized manner. Recent results show that signals initiated during the induction phase already program a default termination procedure that enables temporally and spatially regulated NF-kappaB deactivation. All negative feedback mechanisms occur with a characteristic time delay, thereby permitting full NF-kappaB function during the interim period. Some proteins that direct termination are produced directly in response to NF-kappaB activation, whereas others are activated via inducible binding or by protein stabilization. Another time-delaying strategy of NF-kappaB feedback inhibitory proteins relies on their ability to function as timers and molecular clockworks with the intrinsic property to terminate their own activity within a preset period.