ABINs: A20 binding inhibitors of NF-kappa B and apoptosis signaling

Potential probiotic Lactiplantibacillus plantarum strains alleviate TNF-α by regulating ADAM17 protein and ameliorate gut integrity through tight junction protein expression in in vitro model

BACKGROUND

Lactiplantibacillus species are extensively studied for their ability to regulate host immune responses and functional therapeutic potentials. Nevertheless, there is a lack of understanding on the mechanisms of interactions with the hosts during immunoregulatory activities.

METHODS

Two Lactiplantibacillus plantarum strains MKMB01 and MKMB02 were tested for probiotic potential following Indian Council of Medical Research (ICMR) guidelines. Human colorectal adenocarcinoma cells such as HT-29, caco-2, and human monocytic cell THP-1 were also used to study the potential of MKMB01 and MKMB02 in regulating the host immune response when challenged with enteric pathogen Salmonella enterica typhimurium. Cells were pre-treated with MKMB01 and MKMB02 for 4 h and then stimulated with Salmonella. qRT-PCR and ELISA were used to analyze the genes and protein expression. Confocal microscopy and field emission scanning electron microscopy (FESEM) were used to visualize the effects. An Agilent Seahorse XF analyzer was used to determine real-time mitochondrial functioning.

RESULTS

Both probiotic strains could defend against Salmonella by maintaining gut integrity via expressing tight junction proteins (TJPs), MUC-2, and toll-like receptors (TLRs) negative regulators such as single Ig IL-1-related receptor (SIGIRR), toll-interacting protein (Tollip), interleukin-1 receptor-associated kinase (IRAK)-M, A20, and anti-inflammatory transforming growth factor-β and interleukin-10. Both strains also downregulated the expression of pro-inflammatory cytokines/chemokines interleukin-1β, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor-alpha (TNF-α), interleukin 6, and nitric oxide (NO). Moreover, TNF-α sheddase protein, a disintegrin and metalloproteinase domain 17 (ADAM17), and its regulator iRhom2 were downregulated by both strains. Moreover, the bacteria also ameliorated Salmonella-induced mitochondrial dysfunction by restoring bioenergetic profiles, such as non-mitochondrial respiration, spare respiratory capacity (SRC), basal respiration, adenosine triphosphate (ATP) production, and maximal respiration.

CONCLUSIONS

MKMB01 and MKMB02 can reduce pathogen-induced gut-associated disorders and therefore should be further explored for their probiotic potential.

The course of cytokine and chemokine gene expression in clinically suspect arthralgia patients during progression to inflammatory arthritis

OBJECTIVES

Autoantibody responses increase years before the onset of inflammatory arthritis (IA) and are stable during transitioning from clinically suspect arthralgia (CSA) to IA. Cytokine and chemokine levels also increase years before IA onset. However, the course in the at-risk stage of CSA during progression to disease or non-progression is unknown. To increase the understanding of processes mediating disease development, we studied the course of cytokine, chemokine and related receptors gene expression in CSA patients during progression to IA and in CSA patients who ultimately did not develop IA.

METHODS

Whole-blood RNA expression of 37 inflammatory cytokines, chemokines and related receptors was determined by dual-colour reverse transcription multiplex ligation-dependent probe amplification in paired samples of CSA patients at CSA onset and either at IA development or after 24 months without IA development. ACPA-positive and ACPA-negative CSA patients developing IA were compared at CSA onset and during progression to IA. Generalised estimating equations tested changes over time. A false discovery rate approach was applied.

RESULTS

None of the cytokine/chemokine genes significantly changed in expression between CSA onset and IA development. In CSA patients without IA development, G-CSF expression decreased (P = 0.001), whereas CCR6 and TNIP1 expression increased (P < 0.001 and P = 0.002, respectively) over a 2 year period. Expression levels in ACPA-positive and ACPA-negative CSA patients who developed IA were similar.

CONCLUSION

Whole-blood gene expression of assessed cytokines, chemokines and related receptors did not change significantly from CSA to IA development. This suggests that changes in expression of these molecules may not be related to the final process of developing chronicity and may have occurred preceding CSA onset. Changes in gene expression in CSA patients without IA development may provide clues for processes related to resolution.

Establishment and characterization of a new activated B-cell-like DLBCL cell line, TMD12

We report the establishment of a novel activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) cell line, designated as TMD12, from a patient with highly refractory DLBCL. ABC-DLBCL is a subtype with a relatively unfavorable prognosis that was originally categorized using gene expression profiling according to its cell of origin. TMD12 cells were isolated from the pleural effusion of the patient at relapse and passaged continuously in vitro for >4 years. The cells displayed cluster of differentiation (CD)19, CD20, CD22, CD38, human leukocyte antigen-DR isotype, and κ positivity and CD5, CD10, CD23, and λ negativity, as detected using flow cytometric analysis. The chromosomal karyotypic analysis, including the spectral karyotyping method, confirmed t(1;19)(q21:q13.1), del(6q23), gain of chromosome 18, and other abnormalities. Mutation analyses, including whole-exome sequencing, revealed that TMD12 cells harbored mutations in MYD88 and CD79B, indicating an ABC subtype. TMD12 cells exhibited chronic active B-cell receptor signaling and constitutive activation of the nuclear factor κB pathway, which is typically associated with sensitivity to a specific Bruton tyrosine kinase inhibitor, ibrutinib. Intriguingly, TMD12 cells displayed moderate resistance to ibrutinib and lacked activation of Janus kinase/signal transducers and activators of transcription 3 signaling, another hallmark of this DLBCL subtype. Treatment with an inhibitor against tumor progression locus 2 (TPL2), a multifunctional intracellular kinase that is activated particularly downstream of Toll-like receptors or MYD88 and IκB kinase α/β (IKKα/β), suppressed the proliferation of TMD12 cells, implying the possible involvement of the TPL2-p105 pathway in the tumorigenesis of ABC-DLBCL. Because only a limited number of ABC-DLBCL cell lines are currently available, TMD12 cells might provide a useful tool in the search for novel druggable targets for this intractable lymphoma.

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele.

Oncogenetic landscape of lymphomagenesis in coeliac disease

OBJECTIVE

Enteropathy-associated T-cell lymphoma (EATL) is a rare but severe complication of coeliac disease (CeD), often preceded by low-grade clonal intraepithelial lymphoproliferation, referred to as type II refractory CeD (RCDII). Knowledge on underlying oncogenic mechanisms remains scarce. Here, we analysed and compared the mutational landscape of RCDII and EATL in order to identify genetic drivers of CeD-associated lymphomagenesis.

DESIGN

Pure populations of RCDII-cells derived from intestinal biopsies (n=9) or sorted from blood (n=2) were analysed by whole exome sequencing, comparative genomic hybridisation and RNA sequencing. Biopsies from RCDII (n=50), EATL (n=19), type I refractory CeD (n=7) and uncomplicated CeD (n=18) were analysed by targeted next-generation sequencing. Moreover, functional in vitro studies and drug testing were performed in RCDII-derived cell lines.

RESULTS

80% of RCDII and 90% of EATL displayed somatic gain-of-functions mutations in the JAK1-STAT3 pathway, including a remarkable p.G1097 hotspot mutation in the JAK1 kinase domain in approximately 50% of cases. Other recurrent somatic events were deleterious mutations in nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) regulators TNFAIP3 and TNIP3 and potentially oncogenic mutations in TET2, KMT2D and DDX3X. JAK1 inhibitors, and the proteasome inhibitor bortezomib could block survival and proliferation of malignant RCDII-cell lines.

CONCLUSION

Mutations activating the JAK1-STAT3 pathway appear to be the main drivers of CeD-associated lymphomagenesis. In concert with mutations in negative regulators of NF-κB, they may favour the clonal emergence of malignant lymphocytes in the cytokine-rich coeliac intestine. The identified mutations are attractive therapeutic targets to treat RCDII and block progression towards EATL.

A20 and ABIN-1 cooperate in balancing CBM complex-triggered NF-κB signaling in activated T cells

T cell activation initiates protective adaptive immunity, but counterbalancing mechanisms are critical to prevent overshooting responses and to maintain immune homeostasis. The CARD11-BCL10-MALT1 (CBM) complex bridges T cell receptor engagement to NF-κB signaling and MALT1 protease activation. Here, we show that ABIN-1 is modulating the suppressive function of A20 in T cells. Using quantitative mass spectrometry, we identified ABIN-1 as an interactor of the CBM signalosome in activated T cells. A20 and ABIN-1 counteract inducible activation of human primary CD4 and Jurkat T cells. While A20 overexpression is able to silence CBM complex-triggered NF-κB and MALT1 protease activation independent of ABIN-1, the negative regulatory function of ABIN-1 depends on A20. The suppressive function of A20 in T cells relies on ubiquitin binding through the C-terminal zinc finger (ZnF)4/7 motifs, but does not involve the deubiquitinating activity of the OTU domain. Our mechanistic studies reveal that the A20/ABIN-1 module is recruited to the CBM complex via A20 ZnF4/7 and that proteasomal degradation of A20 and ABIN-1 releases the CBM complex from the negative impact of both regulators. Ubiquitin binding to A20 ZnF4/7 promotes destructive K48-polyubiquitination to itself and to ABIN-1. Further, after prolonged T cell stimulation, ABIN-1 antagonizes MALT1-catalyzed cleavage of re-synthesized A20 and thereby diminishes sustained CBM complex signaling. Taken together, interdependent post-translational mechanisms are tightly controlling expression and activity of the A20/ABIN-1 silencing module and the cooperative action of both negative regulators is critical to balance CBM complex signaling and T cell activation.

Genetic variants in IL-17A rs10484879 and serum levels of IL-17A are associated with psoriasis risk

Psoriasis is an inflammatory skin disease characterized by keratinocyte hyperproliferation with effective environmental and genetic factors. Recent studies showing that the IL-23/IL-17 axis plays a central role in the pathogenesis of the disease. Experimental and clinical studies suggest that IL-17A, an important regulatory effector cytokine in this pathway and triggers changes mainly in affected tissues. Based on the central role of IL-17A in the pathogenesis of psoriasis, we thought that variations in this gene could affect the susceptibility and severity of this disease. Therefore, in this study, we aimed to analyze whether IL-17A rs10484879 variant has an effect on psoriasis pathogenesis in Turkish population. In this case-control study, the study group consisting of 564 patient (188 psoriasis patients (66 males/122 females)/376 controls (132 males/244 females) and they were genotyped in terms of IL-17A (rs10484879) polymorphism with TaqMan 5 'Allelic Discrimination Test. IL-17A serum levels were measured with the Enzyme-linked immunosorbent assay (ELISA). The genotype distributions of the IL-17A rs10484879 polymorphism between the patient and control groups were statistically different in the TT genotype and it was observed more commonly in the patient group compared to the controls (p < 0.001). Similarly, the T allele was observed with a higher prevalence in the patient group compared to the controls (p = 0.007). IL-17A serum levels were associated with increased serum concentration, respectively, TT > GT > GG in all study groups (p < 0.05). We would like to report that IL-17A rs10484879 TT genotype and T allele are associated with increased risk of psoriasis in the Turkish population.

Inhibitory feedback control of NF-κB signalling in health and disease

Cells must adapt to changes in their environment to maintain cell, tissue and organismal integrity in the face of mechanical, chemical or microbiological stress. Nuclear factor-κB (NF-κB) is one of the most important transcription factors that controls inducible gene expression as cells attempt to restore homeostasis. It plays critical roles in the immune system, from acute inflammation to the development of secondary lymphoid organs, and also has roles in cell survival, proliferation and differentiation. Given its role in such critical processes, NF-κB signalling must be subject to strict spatiotemporal control to ensure measured and context-specific cellular responses. Indeed, deregulation of NF-κB signalling can result in debilitating and even lethal inflammation and also underpins some forms of cancer. In this review, we describe the homeostatic feedback mechanisms that limit and ‘re-set’ inducible activation of NF-κB. We first describe the key components of the signalling pathways leading to activation of NF-κB, including the prominent role of protein phosphorylation and protein ubiquitylation, before briefly introducing the key features of feedback control mechanisms. We then describe the array of negative feedback loops targeting different components of the NF-κB signalling cascade including controls at the receptor level, post-receptor signalosome complexes, direct regulation of the critical ‘inhibitor of κB kinases’ (IKKs) and inhibitory feedforward regulation of NF-κB-dependent transcriptional responses. We also review post-transcriptional feedback controls affecting RNA stability and translation. Finally, we describe the deregulation of these feedback controls in human disease and consider how feedback may be a challenge to the efficacy of inhibitors.

Structural and Biochemical Basis for Higher-Order Assembly between A20-Binding Inhibitor of NF-κB 1 (ABIN1) and M1-Linked Ubiquitins

Polyubiquitination is important in controlling NF-κB signaling. Excessive NF-κB activity has been linked to inflammatory disorders and autoimmune diseases, while ABIN1 could attenuate NF-κB activation to maintain immune homeostasis by utilizing UBAN to recognize linear (M1)-linked polyubiquitinated NF-κB activation mediators, including NEMO, IRAK1 and RIP1. PolyUb-mediated UBAN recruitment remains undetermined, since the recognition studies focused mostly on di-ubiquitin (diUb). Here we report three crystal structures of human ABIN1 UBAN (hABIN1^UBAN) in complex with M1-linked diUb, triUb, and tetraUb, respectively. Notably, the hABIN1^UBAN:diUb structure reveals that a diUb randomly binds one of the Ub-binding sites of the hABIN1^UBAN dimer and leaves the other site vacant. Together with the ITC and gel-filtration analyses, we found that M1-triUb and M1-tetraUb adopt two unique conformations, instead of an elongated one, and they preferentially use the N-terminal two-Ub unit to bind the primary Ub-binding site of a hABIN1^UBAN dimer and the C-terminal two-Ub unit to bind the secondary Ub-binding site of another hABIN1^UBAN dimer. Especially, our results suggest that two ABIN1^UBAN dimers cooperatively bind two UBAN-binding units of a tetraUb or vice versa. Since the UBAN family members share a conserved diUb-binding mode, our results suggest that M1-polyUb modification allows multiple copies of the two-tandem Ub unit to simultaneously coordinate multiple and/or different binding partners to increase their local concentrations and to facilitate the formation of a large signaling complex. Our study provides a structural-functional glimpse of M1-polyUb as a multiple-molecule binding platform to exert its intrinsic structural plasticity in mediating cellular signaling.

Association of TNIP1 polymorphisms with hepatocellular carcinoma in a Northwest Chinese Han population

ABSTRACT

Study has demonstrated that TNIP1 polymorphisms are associated with an increased risk of HBV-induced hepatocellular carcinoma (HCC). The purpose of this study was to investigate the correlation between polymorphisms in TNIP1 and HCC risk in a Northwest Chinese Han population.A case-control study was conducted including 473 Hepatocellular carcinoma patients and 564 healthy controls. Three SNPs (rs3792792, rs7708392, and rs10036748) were genotyped with Sequenom MassARRAY technology and their associations with HCC risk were analyzed. These data were evaluated using the Chi-square test/Fisher's exact test, genetic model analysis, and haplotype analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association.Patients with the "G" allele of TNIP1 rs7708392 showed a significantly increased risk of HCC (OR = 1.24, 95%CI: 1.01-1.52, P = .042). Significant association was also shown between TNIP1 rs7708392 and HCC susceptibility in Additive model (OR = 1.25; 95% CI = 1.01-1.54; P = .040). Besides, we also found that the "GC" haplotype of rs7708392 and rs10036748 was significantly associated with higher occurrence of HCC (OR = 1.25, 95% CI: 1.01-1.54, P = .039).These results demonstrate that TNIP1 polymorphisms are associated with increased HCC risk in a Northwest Chinese Han population for the first time, which warrants further investigation in the future.

Expression and role of ABIN1 in sepsis: In vitro and in vivo studies

In this research, we attempted to explain the effect and the related molecular mechanisms of ABIN1 in lipopolysaccharide (LPS)-induced septic mice or RAW264.7 macrophages. LPS was adopted to treat RAW264.7 macrophages for 4 h, and the levels of inflammatory factors were assessed by ELISA. Besides, ABIN1 expression was measured by quantitative reverse transcription polymerase chain reaction. Apparently, LPS enhanced immunoreaction, suggested by increased expression of IL-1β, tumor necrosis factor (TNF)-α, and IL-6. ABIN1 levels were obviously reduced compared to the control. Furthermore, we evaluated the roles of ABIN1-plasmid in immunoreaction and nuclear factor-κB (NF-κB) pathway. We found that ABIN1-plasmid significantly reduced the expression of IL-1β, TNF-α, and IL-6 in LPS-treated cells and inhibited NF-κB pathway activation. Meanwhile, a septic mouse mode was conducted to validate the role of ABIN1 in inflammatory response and organ damage in vivo. These data suggested that ABIN1-plasmid significantly inhibited the secretion of inflammatory cytokines and Cr, BUN, AST, and ALT levels in the serum of LPS-stimulated mice compared to LPS + control-plasmid group, reflecting the relieved inflammation and organ injury. In summary, the present findings indicated that ABIN1 alleviated sepsis by repressing inflammatory response through NF-κB signaling pathway, emphasizing the potential value of ABIN1 as therapeutic strategy for sepsis.

The Anti-Inflammatory Protein TNIP1 Is Intrinsically Disordered with Structural Flexibility Contributed by Its AHD1-UBAN Domain

TNFAIP3 interacting protein 1 (TNIP1) interacts with numerous non-related cellular, viral, and bacterial proteins. TNIP1 is also linked with multiple chronic inflammatory disorders on the gene and protein levels, through numerous single-nucleotide polymorphisms and reduced protein amounts. Despite the importance of TNIP1 function, there is limited investigation as to how its conformation may impact its apparent multiple roles. Hub proteins like TNIP1 are often intrinsically disordered proteins. Our initial in silico assessments suggested TNIP1 is natively unstructured, featuring numerous potentials intrinsically disordered regions, including the ABIN homology domain 1-ubiquitin binding domain in ABIN proteins and NEMO (AHD1-UBAN) domain associated with its anti-inflammatory function. Using multiple biophysical approaches, we demonstrate the structural flexibility of full-length TNIP1 and the AHD1-UBAN domain. We present evidence the AHD1-UBAN domain exists primarily as a pre-molten globule with limited secondary structure in solution. Data presented here suggest the previously described coiled-coil conformation of the crystallized UBAN-only region may represent just one of possibly multiple states for the AHD1-UBAN domain in solution. These data also characterize the AHD1-UBAN domain in solution as mostly monomeric with potential to undergo oligomerization under specific environmental conditions (e.g., binding partner availability, pH-dependence). This proposed intrinsic disorder across TNIP1 and within the AHD1-UBAN region is likely to impact TNIP1 function and interaction with its multiple partners.

Role of microRNA-15a-5p/TNFAIP3-interacting protein 2 axis in acute lung injury induced by traumatic hemorrhagic shock

The present study aimed to investigate the role of microRNA (miR)-15a-5p in the pathogenesis of acute lung injury induced by traumatic hemorrhagic shock (THS), and to explore the underlying molecular mechanism. The expression level of miR-15a-5p was detected using reverse transcription-quantitative (RT-qPCR) and the association between miR-15a-5p and TNFAIP3-interacting protein 2 (TNIP2) was revealed using TargetScan and dual luciferase reporter assays. To investigate the effect of miR-15a-5p on THS-induced acute lung injury, a THS rat model was established. Lung capillary permeability and lung edema were then determined. Moreover, proinflammatory factors in the bronchoalveolar lavage fluid (BALF) and serum of the THS rat model were detected using ELISA. In addition, protein levels in the current study were measured via western blotting. It was revealed that miR-15a-5p was significantly upregulated in both patients with THS and samples from the THS rat model. TNIP2 represents a direct target of miR-15a-5p, and it was downregulated in both patients with THS and the THS rat model. Further analyses indicated that downregulation of miR-15a-5p significantly relieved acute lung injury induced by THS, evidenced by a decreased ratio of Evan's blue dye (EBD) in the BALF to EBD in plasma of THS rats, decreased lung permeability index and reduced lung wet/dry ratio. Inhibition of miR-15a-5p also decreased THS-induced upregulation of pro-inflammatory factors. Furthermore, the data revealed that THS-induced NF-κB activation in the lung tissues of rats was inhibited by miR-15a-5p knockdown. Moreover, it was demonstrated that all the effects of miR-15a-5p on THS rats were ablated following TNIP2 silencing. Taken together, the data of the current study indicate that miR-15a-5p downregulation serves a protective role in THS-induced acute lung injury via directly targeting TNIP2.

A20-Binding Inhibitor of NF-κB 1 Ameliorates Neuroinflammation and Mediates Antineuroinflammatory Effect of Electroacupuncture in Cerebral Ischemia/Reperfusion Rats

A20-binding inhibitor of NF-κB 1 (ABIN1) is an inhibitor of NF-κB and exerts anti-inflammatory effect. Electroacupuncture (EA) is considered as a neuroprotective strategy by inhibiting neuroinflammatory damage after cerebral ischemia. This study was performed to explore the role of ABIN1 and investigate whether the ABIN1 is involved in the mechanism of EA in cerebral ischemia/reperfusion (I/R) rats. Male Sprague-Dawley (SD) rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and received EA after reperfusion once a day. Lentivirus-mediated ABIN1 gene knockdown was used to detect the role of ABIN1 in neuroinflammation after I/R. ABIN1 expression, proinflammatory cytokine levels, microglial activation, neurological function, infarct volumes, and NF-κB activation were assessed. ABIN1 expression was elevated in the peri-infarct cortex and was further upregulated by EA. ABIN1 knockdown increased the levels of proinflammatory cytokines and activation of microglia, worsened neurological deficits, and enlarged the infarct volume. Moreover, ABIN1 was blocked to partially reverse the neuroprotective effect of EA, and this treatment weakened the ability of EA to suppress NF-κB activity. Based on these findings, ABIN1 is a potential suppressor of neuroinflammation and ABIN1 mediates the antineuroinflammatory effect of EA in cerebral I/R rats.

Liquiritin protects PC12 cells from corticosterone-induced neurotoxicity via regulation of metabolic disorders, attenuation ERK1/2-NF-κB pathway, activation Nrf2-Keap1 pathway, and inhibition mitochondrial apoptosis pathway

Liquiritin, a flavone derived from the medicine food homology plant liquorice, possesses neuroprotective. However, the neuroprotective mechanism is not clear. In this study, metabolomics based LC-MS was performed to discover the metabolite changes in PC12 cells treated with corticosterone-induced neurotoxicity after liquiritin treatment. A total of 30 metabolites were identified as differential metabolites. Among them, 11 metabolites were regulated by liquiritin, and involved in the D-glutamine and D-glutamate metabolism, and glutathione metabolism, etc. Based on the results of metabolomics, three cell signaling pathways related to these metabolic pathways were verified. The results showed that the ERK1/2-NF-κB pathway related to the D-glutamine and D-glutamate metabolism was attenuated by liquiritin via down-regulation phospho-ERK1/2, phospho-IκBα, phospho-NF-κB protein expression levels. Furthermore, the Nrf2-Keap1 pathway related to glutathione metabolism was activated by liquiritin via up-regulation Nrf2, Keap1, HO-1, NQO1 protein expression levels, and increased SOD, CAT, GSH-PX enzyme activity, thus exerting antioxidant activity. Additionally, liquiritin inhibited the mitochondrial apoptosis by decreasing the Ca²⁺ concentration, improving MMP, up-regulating Bcl-2, and down-regulating Bax, cytochrome C, cleaved-Caspase-3 expression levels. These results suggest that the neuroprotective mechanisms of liquiritin are connected to the regulation of metabolic disorders, activation Nrf2/Keap1 pathway, attenuation ERK1/2/NF-κB pathway, and inhibition mitochondrial apoptosis pathway.

ABIN-1 protects chondrocytes from lipopolysaccharide-induced inflammatory injury through the inactivation of NF-κB signalling

The A20-binding inhibitor of nuclear factor (NF)-κB-1 (ABIN-1) protein has recently been implicated as a key regulator of inflammation with involvement in multiple inflammatory diseases. However, the function of ABIN-1 in osteoarthritis (OA) remains unclear. In the current study, we explored the role of ABIN-1 in the regulation of lipopolysaccharide (LPS)-induced inflammatory injury of chondrocytes, which served as an in vitro model of OA. Results revealed that ABIN-1 expression was induced by chondrocyte exposure to LPS. ABN-1 silencing exacerbated LPS-induced apoptosis and the inflammatory response, while ABIN-1 overexpression alleviated the inflammatory response and LPS-induced apoptosis in chondrocytes. Moreover, ABIN-1 overexpression resulted in significantly decreased LPS-induced NF-κB activation. Notably, activation of NF-κB signalling significantly reversed ABIN-1-mediated inhibitory effects on LPS-induced inflammatory injury in chondrocytes. Taken together, these results demonstrate that ABIN-1 protects chondrocytes against LPS-induced inflammatory injury through the suppression of NF-κB signalling. Our study suggests a potential role for ABIN-1 in OA. Further, we show that ABIN-1 may serve as a potential target for controlling joint inflammation.

Modulation of Toll-like receptor-mediated innate immunity in bovine intestinal epithelial cells by lactic acid bacteria isolated from feedlot cattle

The ability of lactobacilli isolated from feedlot cattle environment to differentially modulate the innate immune response triggered by Toll-like receptors (TLRs) activation in bovine intestinal epithelial (BIE) cells was evaluated. BIE cells were stimulated with Lactobacillus mucosae CRL2069, Lactobacillus acidophilus CRL2074, Lactobacillus fermentum CRL2085 or Lactobacillus rhamnosus CRL2084 and challenged with heat-stable pathogen associated molecular patterns (PAMPs) from enterotoxigenic Escherichia coli (ETEC) to induce the activation of TLR4 or with polyinosinic:polycytidylic acid (poly(I:C)) to activate TLR3. Type I interferons, cytokines, chemokines and negative regulators of TLR signalling were studied by RT-PCR. L. mucosae CRL2069 significantly reduced the expression of interleukin (IL)-8 and monocyte chemoattractant protein (MCP)-1 in BIE cells in the context of TLR3 activation. L. mucosae CRL2069 also reduced the expression of tumour necrosis factor-α, IL-β, MCP-1, and IL-8 in heat-stable ETEC PAMPs-challenged BIE cells. In addition, reduced expressions of IL-6, MCP-1, and IL-8 were found in BIE cells stimulated with L. rhamnosus CRL2084, although its effect was significantly lower than that observed for the CRL2069 strain. The reduced levels of pro-inflammatory factors in BIE cells induced by the CRL2069 and CRL2085 strains was related to their ability of increasing the expression of TLR negative regulators. L. mucosae CRL2069 significantly improved the expression of A20-binding inhibitor of NFκ-B activation 3 (ABIN-3), interleukin-1 receptor-associated kinase M (IRAK-M) and mitogen-activated protein kinase 1 (MKP-1) while L. rhamnosus CRL2084 augmented ABIN-3 expression in BIE cells. The results of this work suggest that among the studied strains, L. mucosae CRL2069 was able to regulate TLR3-mediated innate immune response and showed a remarkable capacity to modulate TLR4-mediated inflammation in BIE cells. The CRL2069 strain induce the up-regulation of three TLR negative regulators that would influence nuclear factor kB and mitogen-activated protein kinases signalling pathways while reducing the expression of pro-inflammatory cytokines and chemokines. Therefore, L. mucosae CRL2069 is an interesting immunobiotic candidate for the protection of the bovine host against TLR-mediated intestinal inflammatory damage.

TNFAIP3 Interacting Protein 3 Overexpression Suppresses Nonalcoholic Steatohepatitis by Blocking TAK1 Activation

Nonalcoholic steatohepatitis (NASH) is an unmet clinical challenge due to the rapid increase in its occurrence but the lack of approved drugs to treat it. Further unraveling of the molecular mechanisms underlying NASH may identify potential successful drug targets for this condition. Here, we identified TNFAIP3 interacting protein 3 (TNIP3) as a novel inhibitor of NASH. Hepatocyte-specific TNIP3 transgenic overexpression attenuates NASH in two dietary models in mice. Mechanistically, this inhibitory effect of TNIP3 is independent of its conventional role as an inhibitor of TNFAIP3. Rather, TNIP3 directly interacts with TAK1 and inhibits its ubiquitination and activation by the E3 ligase TRIM8 in hepatocytes in response to metabolic stress. Notably, adenovirus-mediated TNIP3 expression in the liver substantially blocks NASH progression in mice. These results suggest that TNIP3 may be a promising therapeutic target for NASH management.

Limonin ameliorates acetaminophen-induced hepatotoxicity by activating Nrf2 antioxidative pathway and inhibiting NF-κB inflammatory response via upregulating Sirt1

BACKGROUND

Limonin, a bioactive compound from citrus plants, exerts antioxidant activities, however its therapeutic potential in acetaminophen (APAP)-induced hepatotoxicity remains unclear.

PURPOSE

Our study aims to investigate the protective effect of limonin on APAP-induced hepatotoxicity and illuminate the underlying mechanisms.

STUDY

design In vitro, we chose L-02 cells to establish in vitro APAP-induced liver injury model. L-02 cells were treated with APAP (7.5 mM) for 24 h after pre-incubation with limonin (10, 25, 50 μM) or NAC (250 μM) for 2 h. In vivo, we used C57BL/6 mice as an in vivo APAP-induced liver injury model. C57BL/6 mice with pre-treatment of limonin (40, 80 mg/kg) or NAC (150 mg/kg) for 1 h, were given with a single dose of APAP (300 mg/kg).

METHODS

After pre-incubation with limonin (10, 25, 50 μM) for 2 h, L-02 cells were treated with APAP (7.5 mM) for 24 h.The experiments in vitro included MTT assay, Annexin V/PI staining, measurement of reactive oxygen species (ROS), quantitative real-time PCR analysis, Western blot analysis, immunofluorescence microscopy and analysis of LDH activity. Transfection of Nrf2 or Sirt1 siRNA was also conducted in vitro. In vivo, C57BL/6 mice with pre-treatment of limonin (40, 80 mg/kg) or NAC (150 mg/kg) for 1 h, were given with a single dose of APAP (300 mg/kg). Mice were sacrificed at 4, 12 h after APAP poisoning, and analysis of ALT and AST in serum, GSH level in liver tissues, liver histological observation and immunohistochemistry were performed.

RESULTS

Limonin increased the cell viability and alleviated APAP-induced apoptosis in hepatocytes. Limonin also inhibited APAP-induced mitochondrial-mediated apoptosis by decreasing the ratio of Bax/Bcl-2, recovery of mitochondrial membrane potential (MMP), inhibiting ROS production and cleavage of caspase-3 in L-02 cells. Moreover, limonin induced activation of Nrf2 and increased protein expression and mRNA levels of its downstream targets, including HO-1, NQO1 and GCLC/GCLM. The inhibition of limonin on apoptosis and promotion on Nrf2 antioxidative pathway were lessened after the application of Nrf2 siRNA. In addition, limonin inhibited NF-κB transcriptional activation, NF-κB-regulated genes and protein expression of inflammatory related proteins iNOS and COX2. Furthermore, limonin increased the protein expression of Sirt1. Sirt1 siRNA transfection confirmed that limonin activated Nrf2 antioxidative pathway and inhibited NF-κB inflammatory response by upregulating Sirt1. Finally, we established APAP-induced liver injury in vivo and demonstrated that limonin alleviated APAP-induced hepatotoxicity by activating Nrf2 antioxidative signals and inhibiting NF-κB inflammatory response via upregulating Sirt1.

CONCLUSION

In summary, this study documented that limonin mitigated APAP-induced hepatotoxicity by activating Nrf2 antioxidative pathway and inhibiting NF-κB inflammatory response via upregulating Sirt1, and demonstrated that limonin had therapeutic promise in APAP-induced liver injury.

Associations of gene polymorphisms in interferon-alpha signature-related genes with autoimmune thyroid diseases

Interferon (IFN)-α treatment predisposes patients to the occurrence of autoimmune thyroid disease (AITD).

METHODS

We investigated associations of single nucleotide polymorphisms (SNPs) of molecules participating in the IFN-α signature, including rs2304204 and rs2304206 of IFN regulatory factor 3 (IRF3), rs1061501 of IRF7, and rs7708392 of TNFA1P3-interacting protein 1 with serum IFN-α levels and AITD in an ethnic Chinese (ie Taiwanese) population. Totally, 319 patients with Graves' disease (GD), 83 patients with Hashimoto's thyroiditis (HT) and 351 healthy controls were recruited.

RESULTS

There were increased percentages of the C allele, and CC and TC + CC genotypes of rs1061501 in GD patients compared to the controls. HT patients had higher serum IFN-α levels compared to the controls, while there was no difference in serum IFN-α levels between patients with GD and controls. However, patients with GD in a remission status had lower serum IFN-α levels than those without remission. On the other hand, the C allele of rs1061501 was only associated with serum IFN-α levels in patients with HT.

CONCLUSIONS

The SNP rs1061501 of IRF7 was associated with the development of GD. Serum IFN-α levels were associated with HT, while they might modify the disease status of GD. Moreover, a genetic effect of rs1061501 on regulating serum IFN-α production was observed in HT.

TNIP1 Inhibits Proliferation And Promotes Apoptosis In Clear Cell Renal Carcinoma Through Targeting C/Ebpβ

Background/Purpose

TNF-α-induced protein 3-interacting protein 1 (TNIP1) is active in various cancers, but its expression and function in renal cell carcinoma (RCC) have not been described. This study investigated the role of TNIP1 in clear cell renal cell carcinomas (ccRCC), which accounts for 75–80% of RCC and has a poor prognosis.

Methods

The expression of TNIP1 in human ccRCC tissues and cells was detected by real-time quantitative reverse transcription–polymerase chain reaction (qRT-PCR), Western blot (WB), and immunohistochemical (IHC) staining. Cell proliferation was assayed by a cell counting kit (CCK)-8 assay; cell cycle analysis and apoptosis assay were done by flow cytometry.

Results

TNIP1 is downregulated in both ccRCC human tissues and cells. Besides, TNIP1 downregulation promoted cell proliferation with more cell cycle entry, and inhibited apoptosis. TNIP1 downregulation was associated with increased of expression of the Bcl-2 anti-apoptosis gene and decreased expression of the Bax apoptosis-promoting gene and cleaved-caspase-3 by negatively regulating C/EBPβ expression.

Conclusion

TNIP1 acted as a tumor-inhibitor in ccRCC by targeting C/EBPβ. The results warrant study of TNIP1 as a potential diagnostic marker and therapeutic target of ccRCC.

TNIP1-mediated TNF-α/NF-κB signalling cascade sustains glioma cell proliferation

As a malignant tumour of the central nervous system, glioma exhibits high incidence and poor prognosis. Although TNIP1 and the TNF‐α/NF‐κB axis play key roles in immune diseases and inflammatory responses, their relationship and role in glioma remain unknown. Here, we revealed high levels of TNIP1 and TNF‐α/NF‐κB in glioma tissue. Glioma cell proliferation was activated with TNF‐α treatment and showed extreme sensitivity to the TNF receptor antagonist. Furthermore, loss of TNIP1 disbanded the A20 complex responsible for IκB degradation and NF‐κB nucleus translocation, and consequently erased TNFα‐induced glioma cell proliferation. Thus, our investigation uncovered a vital function of the TNIP1‐mediated TNF‐α/NF‐κB axis in glioma cell proliferation and provides novel insight into glioma pathology and diagnosis.

Association of genetic polymorphism of interleukin-17A & interleukin-17F with susceptibility of psoriasis

Background & objectives:

Psoriasis is a chronic inflammatory skin disease with unknown aetiology. So far studies have confirmed that interleukins, pro-inflammatory factors and T-cell activation play major role in the development of disease. Interleukin-17 (IL-17) a T helper inflammatory cytokine, was found to be positively correlated with severity of psoriasis. However, the specific mechanism has not been clarified. IL-17A and IL-17F are group members of IL17 family cytokines and found to be located adjacent to one another on the same human chromosome, 6p12. The present study was designed to identify the association between IL-17A and IL-17F gene polymorphism with susceptibility of psoriasis in north Indian population.

Methods:

A total of 166 psoriasis patients and 150 healthy controls were genotyped for IL-17A and IL-17F gene polymorphism by amplification refractory mutation system-polymerase chain reaction method. One single nucleotide polymorphism (SNP) was analysed in IL-17A (rs10484879) and one SNP in IL-17F (rs763780) to look for an association with psoriasis.

Results:

Our study indicated decreased frequency of IL-17A (rs10484879) G allele (51.8 vs. 65.0%), and IL-17F (rs763780) C allele (36.5 vs. 45.7%) in psoriatic patients as compared to healthy controls.

Interpretation & conclusions:

The present findings suggest that IL-17A (rs10484879) G/T and IL-17F (rs763780) C/T gene polymorphisms may contribute in pathogenesis of psoriasis. Further studies need to be done to confirm these findings.

The Functional Role of Prostate Cancer Metastasis-related Micro-RNAs

The mortality of patients with hormone-resistant prostate cancer can be ascribed to a large degree to metastasis to distant organs, predominantly to the bones. In this review, we discuss the contribution of micro-RNAs (miRs) to the metastatic process of prostate cancer. The criteria for selection of miRs for this review were the availability of preclinical in vivo metastasis-related data in conjunction with prognostic clinical data. Depending on their function in the metastatic process, the corresponding miRs are up- or down-regulated in prostate cancer tissues when compared to matching normal tissues. Up-regulated miRs preferentially target suppressors of cytokine signaling or tumor suppressor-related genes and metastasis-inhibitory transcription factors. Down-regulated miRs promote epithelial-mesenchymal transition or mesenchymal-epithelial transition and diverse pro-metastatic signaling pathways. Some of the discussed miRs exert their function by simultaneously targeting epigenetic pathways as well as cell-cycle-related, anti-apoptotic and signaling-promoting targets. Finally, we discuss potential therapeutic options for the treatment of prostate cancer-related metastases by substitution or inhibition of miRs.

Expression and role of TNIP2 in multiple organ dysfunction syndrome following severe trauma

Severe trauma can result in secondary multiple organ dysfunction syndrome (MODS) and death. Inflammation response and oxidative stress promote the occurrence and development of MODS. TNFAIP3‑interacting protein 2 (TNIP2), which can repress the activation of nuclear factor‑κB (NF‑κB) and may be involved in MODS progression, has not been studied in regards to MODS. The present study aimed to investigate the expression, role and mechanism of TNIP2 in MODS following severe trauma. The expression level of TNIP2 was initially detected in the blood of patients with MODS using reverse transcription‑quantitative polymerase chain reaction and western blot assay. Then, to investigate the role of TNIP2 in MODS, a MODS rat model was conducted by trauma and the model rats were treated with TNIP2‑plasmid (intraperitoneal injection). Blood levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), creatine (Cr) and creatine kinase (CK); and tumor necrosis factor α (TNF‑α), high‑mobility group box 1 (HMGB‑1), malondialdehyde (MDA) and total antioxidant capacity (TAC) in the different groups were assessed. In addition, activation of NF‑κB was assessed by detecting the level of phospho‑p65. The results showed that TNIP2 was significantly decreased in the blood of patients with MODS. TNIP2 was also significantly downregulated in the blood and the pulmonary, renal and hepatic tissues of MODS rats. The levels of ALT, AST, LDH, BUN, Cr and CK were markedly increased in the blood of MODS rats, and these increases were inhibited by TNIP2‑plasmid administration. Moreover, blood levels of TNF‑α, HMGB‑1 and MDA were significantly increased in MODS rats, while TAC was notably decreased, and these changes were prevented by TNIP2‑plasmid administration. Furthermore, it was found that activation of NF‑κB induced by MODS was eliminated by TNIP2‑plasmid. In conclusion, the data indicated that TNIP2 is significantly decreased in MODS following severe trauma, and it plays a protective role in MODS development by inhibiting the inflammation response and oxidative stress by preventing NF‑κB activation.

Erythropoietin Treatment Ameliorates Lupus Nephritis of MRL/lpr Mice

An increasing body of data has shown that erythropoietin (EPO) plays multiple roles in inflammation control and immunoregulation. However, less attention has been given to its effects on lupus nephritis (LN). In this study, we investigated the therapeutic effects of EPO on LN in MRL/lpr mice, a well-studied animal model for lupus. MRL/lpr mice were randomly divided into an EPO and control group. Mice in the EPO group were treated with EPO; saline was given to the control group. Both groups were treated for 10 weeks. We analyzed the differences of general disease condition, histopathologic changes, Th lymphocytes subsets, and the expression of inflammatory factors of mice between the groups. Compared to the control group, mice in the EPO group showed less spleen hyperplasia, less urinary protein, and lower serum anti-dsDNA antibody; they also had lower renal histopathologic scores and less deposition of IgG/C3 within glomeruli. Moreover, Th1 and Th17 levels were decreased, while Th2 and Treg levels were increased in the spleen, and the expression of inflammatory cytokines decreased in both the spleen and kidneys. EPO increased Th2 and Treg lymphocytes, decreased Th1, Th17 lymphocytes in the spleen, and inhibited the inflammatory reactions in both the spleen and kidneys, thus ameliorating LN of MRL/lpr mice.

NLRP10 Affects the Stability of Abin-1 To Control Inflammatory Responses

NOD-like receptors (NLR) are critical regulators of innate immune signaling. The NLR family consists of 22 human proteins with a conserved structure containing a central oligomerization NACHT domain, an N-terminal interaction domain, and a variable number of C-terminal leucine-rich repeats. Most NLR proteins function as cytosolic pattern recognition receptors with activation of downstream inflammasome signaling, NF-κB, or MAPK activation. Although NLRP10 is the only NLR protein lacking the leucine rich repeats, it has been implicated in multiple immune pathways, including the regulation of inflammatory responses toward Leishmania major and Shigella flexneri infection. In this study, we identify Abin-1, a negative regulator of NF-κB, as an interaction partner of NLRP10 that binds to the NACHT domain of NLRP10. Using S. flexneri as an infection model in human epithelial cells, our work reveals a novel function of NLRP10 in destabilizing Abin-1, resulting in enhanced proinflammatory signaling. Our data give insight into the molecular mechanism underlying the function of NLRP10 in innate immune responses.

Differential gene expression in human tissue resident regulatory T cells from lung, colon, and blood

As we learn more about how immune responses occur in situ, it is becoming clear that each organ/tissue is characterized with its own anatomy and microenvironment which may affect and even determine the outcome of the immune responses. With emerging data from animal studies showing that regulatory T cells infiltrating non-lymphoid tissues exhibit unique phenotypes and transcriptional signatures and display functions beyond their well-established suppressive roles, there is an urgent need to explore the function of tissue Treg cells in humans. Here we characterized the transcriptome of Treg residing at the human mucosal tissue obtained from the normal area of cancer resections and their peripheral blood counterparts, identifying human lung and colon tissue Treg signature genes and their upstream regulators. Pathway analysis highlighted potential differences in the cross-talk between tissue Treg cells and other non-immune tissue-specific cell types. For example, genes associated with wnt pathway were differentially regulated in lung Treg cells compared to blood or colon indicating a potential role for lung Treg cells in epithelium repair and regeneration. Moreover, we identified several non-coding RNAs specifically expressed by tissue-resident Tregs. These results provide a comprehensive view of lung and colon tissue Treg transcriptional landscape.

Precision medicine in lupus nephritis: can biomarkers get us there?

Patients with systemic lupus erythematosus frequently develop lupus nephritis (LN), a condition that can lead to end-stage kidney disease. Multiple serum and urine biomarkers for LN have been proposed in recent years, yet none have become incorporated into clinical use. The majority of studies have been single center with significant variability in cohorts, assays, and sample storage, leading to inconclusive results. It has become clear that no single biomarker is likely to be sufficient to diagnose LN, identify flares, and define the response to therapy and prognosis. A more likely scenario is a panel of urine, serum, tissue, and genetic biomarkers. In this review, we summarize traditional and novel biomarkers and discuss how they may be utilized in order to bring precision medicine to clinical practice in LN.

TNIP1 Regulates Cutibacterium acnes-Induced Innate Immune Functions in Epidermal Keratinocytes

Human skin cells recognize the presence of the skin microbiome through pathogen recognition receptors. Epidermal keratinocytes are known to activate toll-like receptors (TLRs) 2 and 4 in response to the commensal Cutibacterium acnes (C. acnes, formerly known as Propionibacterium acnes) bacterium and subsequently to induce innate immune and inflammatory events. These events may lead to the appearance of macroscopic inflammatory acne lesions in puberty: comedos, papules and, pustules. Healthy skin does not exhibit inflammation or skin lesions, even in the continuous presence of the same microbes. As the molecular mechanism for this duality is still unclear, we aimed to identify factors and mechanisms that control the innate immune response to C. acnes in keratinocytes using a human immortalized keratinocyte cell line, HPV-KER, normal human keratinocytes (NHEK) and an organotypic skin model (OSM). TNIP1, a negative regulator of the NF-κB signaling pathway, was found to be expressed in HPV-KER cells, and its expression was rapidly induced in response to C. acnes treatment, which was confirmed in NHEK cells and OSMs. Expression changes were not dependent on the C. acnes strain. However, we found that the extent of expression was dependent on C. acnes dose. Bacterial-induced changes in TNIP1 expression were regulated by signaling pathways involving NF-κB, p38, MAPKK and JNK. Experimental modification of TNIP1 levels affected constitutive and C. acnes-induced NF-κB promoter activities and subsequent inflammatory cytokine and chemokine mRNA and protein levels. These results suggest an important role for this negative regulator in the control of bacterially induced TLR signaling pathways in keratinocytes. We showed that all-trans retinoic acid (ATRA) induced elevated TNIP1 expression in HPV-KER cells and also in OSMs, where TNIP1 levels increased throughout the epidermis. ATRA also reduced constitutive and bacterium-induced levels of TNFα, CCL5 and TLR2, while simultaneously increasing CXCL8 and TLR4 expression. Based on these findings, we propose that ATRA may exhibit dual effects in acne therapy by both affecting the expression of the negative regulator TNIP1 and attenuating TLR2-induced inflammation. Overall, TNIP1, as a possible regulator of C. acnes-induced innate immune and inflammatory events in keratinocytes, may play important roles in the maintenance of epidermal homeostasis.

Loading of doxorubicin and thymoquinone with F2 gel nanofibers improves the antitumor activity and ameliorates doxorubicin-associated nephrotoxicity

AIMS

This study aimed to elucidate the benefits of nanoformulation of doxorubicin (DOX) and thymoquinone (TQ) loaded with nanofibers of poly-N-acetyl glucosamine (pGlcNAc), which is known as F2 gel, over their conventional free forms. Moreover, evaluate the role of TQ in improving chemotherapeutic effect and ameliorating nephrotoxicity of DOX.

MAIN METHODS

The drugs were loaded into F2 gel followed by measurement of physicochemical characterization. Next, MCF-7 and HEPG2 cells were treated with the prepared formulations and assessed for apoptosis alongside with cellular proliferation. Furthermore, we experimentally induced Heps liver carcinoma in mice and at the end of the treatment, mice were sacrificed and serum samples were used to assess nephrotoxicity markers; blood urea nitrogen (BUN) and creatinine. Additionally, renal tissue was used for determination of oxidative markers and antioxidant enzymes; whereas, tumor tissue was utilized to measure nuclear factor kappa B (NF-κB) and caspase 3.

KEY FINDINGS

Nanoformulation showed dramatic increase in apoptosis, caspase 3, and antioxidant enzymes; in contrast to, dramatic fall in cell viability, tumor volume, oxidative and nephrotoxicity markers, and NF-κB compared to corresponding free therapies. Combined therapy was superior in conserving the measured parameters compared to other treated groups.

SIGNIFICANCE

F2 gel loaded with DOX and TQ revealed enhanced antitumor activity with minimal toxicity. Moreover, using TQ as an adjuvant with DOX could augment its cytotoxicity and ameliorate nephrotoxicity.

Icariin alleviates murine lupus nephritis via inhibiting NF-κB activation pathway and NLRP3 inflammasome

AIMS

Lupus nephritis (LN) is a kidney inflammatory disease caused by systemic lupus erythematosus (SLE). Both NF-κB activation and NLRP3 inflammasome activation are implicated in LN pathogenesis, suggesting they are potential targets for LN treatment. Icariin, which is isolated from Chinese medicine Horny Goat Weed (Ying Yang Huo), has been shown to have anti-inflammation activity, and inhibit activations of both NF-κB and NLRP3 inflammasome. In present study, the effects of icariin on LN were evaluated in MRL/lpr mice.

MAIN METHODS

We treated MRL/lpr mice with icariin for 8 weeks and then analyzed the renal function and kidney pathology. We monitored the levels of anti-dsDNA antibody and the deposition of immune complex after icariin treatment. We also detected the macrophage infiltration, NF-κB activation, NLRP3 inflammasome activation and inflammatory cytokine TNF-α production in MRL/lpr mice after icariin treatment.

KEY FINDINGS

We found that MRL/lpr mice treated with icariin displayed significantly attenuated the renal disease. Icariin-treated mice showed significantly reduced serum anti-dsDNA antibody level and immune complex deposition. Icariin inhibited NF-κB activation and TNF-α production in MRL/lpr mice. Icariin inhibited CCL2 production and macrophage infiltration in MRL/lpr mice. Finally, icariin suppressed NLRP3 inflammasome activation and IL-1β production in MRL/lpr mice.

SIGNIFICANCE

Icariin alleviated murine lupus nephritis via inhibiting NF-κB activation and NLRP3 inflammasome activation.

Tumor necrosis factor α-induced protein 3 (A20) is dysregulated in pediatric Crohn disease

PURPOSE

A significant feature of pediatric inflammatory bowel diseases (IBD), which include Crohn disease (CD), and ulcerative colitis (UC), is failure to suppress inflammation. The inability to regulate inflammation renders a major challenge toward establishing effective treatments in IBD. Nuclear factor kappa-light-chain-enhancer of activated B-cells-induced inflammation is inhibited by A20 through interactions with TAX1BP1 (Tax1-binding protein 1) and A20-binding inhibitor of NF-κβ activation (ABIN)-1 (A20 binding and inhibitor of NF-κβ) and upon phosphorylation by inhibitor of nuclear factor kappa-β kinase subunit beta (IKKβ), which stabilizes it. We hypothesized that dysregulation of A20 is an important factor in uncontrolled inflammation in pediatric IBD.

PATIENTS AND METHODS

Gene expression of A20, IKKβ, ABIN-1, TAX1BP1, A20 protein, cytokine levels, and A20 phosphorylation was analyzed in the terminal ileum (TI) of 39 patients (14 non-IBD, 15 CD, and 10 UC). A20 expression and protein in T-84 cells and ex vivo biopsies of patients were measured after treatment with Escherichia coli strains or tumor necrosis factor (TNF)-α.

RESULTS

TNF-α levels and A20 expression were increased in the TI of CD patients. A20 protein levels and ABIN-1 expression were low, TAX1BP1 expression was high, and IKKβ was unchanged. A20 expression positively correlated with biopsy TNF-α levels and inflammatory markers in CD patients. A20 phosphorylation appeared lower in CD patients. A20 expression in TI biopsies from CD patients and T84 cells was triggered with E. coli, strain LF82, while A20 protein levels remained unchanged.

CONCLUSION

We describe a potential mechanism related to failure of A20 to suppress inflammation in CD, characterized by high A20 expression and low A20 protein levels. The dysregulation of A20 is potentially due to alterations in ABIN-1, and infection with E. coli strain LF82 could affect the function and stability of A20. Our study signifies an important finding in A20 regulation in IBD, which prevents it from suppressing inflammation.

Association between genetic variants and esophageal cancer risk

We investigated whether single nucleotide polymorphisms (SNPs) in the nuclear assembly factor 1 (NAF1) and TNFAIP3-interacting protein 1 (TNIP1) gene were associated with susceptibility to esophageal cancer in a Chinese Han population. Five SNPs were genotyped and their relationship with esophageal cancer risk was analyzed in a sample of 386 esophageal cancer patients and 495 unrelated healthy controls recruited from the First Affiliated Hospital of Xi’an Jiaotong University. Patients with the AG genotype of rs2320615 were at lower risk of developing esophageal cancer than those with the GG genotype (adjusted odds ratio [OR] = 0.64, 95% confidence interval [CI] = 0.46-0.90, P = 0.009). The rs2320615 SNP was found to be associated with a decreased the risk of esophageal cancer in the dominant model (adjusted OR = 0.70, 95% CI = 0.51-0.96, P = 0.026). These results provide the first evidence that the rs2320615 in NAF1 was associated with reduced risk of esophageal cancer. Further studies with larger samples are warranted to confirm our findings.

Association of a single nucleotide polymorphism in TNIP1 with type-1 autoimmune hepatitis in the Japanese population

Several studies reported that autoimmune diseases share a number of susceptibility genes. Of these genes, a SNP rs7708392 in TNIP1 was reported to be associated with systemic lupus erythematosus (SLE). Autoimmune hepatitis (AIH), a rare chronic progressive liver disease, shares some clinical features with SLE. Therefore, we investigated whether the SNP is associated with Japanese AIH. An association study of rs7708392 was conducted in 343 Japanese AIH patients and 828 controls. We found that rs7708392 is associated with AIH (P = 0.0236, odds ratio (OR) 1.26, 95% confidence interval (CI): 1.03-1.54), under the allele model for C allele. Significant differences of clinical characteristics of the AIH patients with or without G allele of rs7708392 were not detected. Of interest, the association was stronger in AIH without HLA-DRB1*04:05 allele (P = 0.0063, Q = 0.0127, OR 1.48, 95% CI: 1.12-1.96), though the association was not detected in AIH with DRB1*04:05. The C allele of rs7708392 was associated with AIH, especially AIH without DRB1*04:05, an already established risk factor.

TNF receptor-activated factor 2 mediates cardiac protection through noncanonical NF-κB signaling

To elucidate the mechanisms responsible for cytoprotective effects of TNF receptor-activated factor 2 (TRAF2) in the heart, we employed genetic gain- and loss-of-function studies ex vivo and in vivo in mice with cardiac-restricted overexpression of TRAF2 (Myh6-TRAF2LC). Crossing Myh6-TRAF2LC mice with mice lacking canonical signaling (Myh6-TRAF2LC/Myh6-IκBαΔN) abrogated the cytoprotective effects of TRAF2 ex vivo. In contrast, inhibiting the JAK/STAT pathway did not abrogate the cytoprotective effects of TRAF2. Transcriptional profiling of WT, Myh6-TRAF2LC, and Myh6-TRAF2LC/Myh6-IκBαΔN mouse hearts suggested that the noncanonical NF-κB signaling pathway was upregulated in the Myh6-TRAF2LC mouse hearts. Western blotting and ELISA for the NF-κB family proteins p50, p65, p52, and RelB on nuclear and cytoplasmic extracts from naive 12-week-old WT, Myh6-TRAF2LC, and Myh6-TRAF2LC/Myh6-IκBαΔN mouse hearts showed increased expression levels and increased DNA binding of p52 and RelB, whereas there was no increase in expression or DNA binding of the p50 and p65 subunits. Crossing Myh6-TRAF2LC mice with RelB-/+ mice (Myh6-TRAF2LC/RelB-/+) attenuated the cytoprotective effects of TRAF2 ex vivo and in vivo. Viewed together, these results suggest that crosstalk between the canonical and noncanonical NF-κB signaling pathways is required for mediating the cytoprotective effects of TRAF2.

TNIP1 reduction sensitizes keratinocytes to post-receptor signalling following exposure to TLR agonists

Cell level inflammatory signalling is a combination of initiation at cell membrane receptors and modulation by cytoplasmic regulatory proteins. For keratinocytes, the predominant cell type in the epidermis, this would include toll-like receptors (TLR) and cytoplasmic proteins that propagate or dampen post-receptor signalling. We previously reported that increased levels of tumor necrosis factor α induced protein 3-interacting protein 1 (TNIP1) in HaCaT keratinocytes leads to decreased expression of stress response and inflammation-associated genes. This finding suggested decreased TNIP1 levels, as seen in some cutaneous disease states, may produce the opposite effect, sensitizing cells to triggers of inflammatory signalling including those sensed by TLR. In this study of TNIP1-deficient HaCaT keratinocytes we examined intracellular signalling consequences especially those expected to produce gene expression changes downstream of TLR3 or TLR2/6 activation by Poly (I:C) or FSL-1, agonists modeling skin relevant pathogens. We found TNIP1-deficient keratinocytes are hyper-sensitive to TLR activation compared to control cells with a normal complement of TNIP1 and receiving the same agonist stimulation. TNIP1-deficient keratinocytes have increased levels of activated (phosphorylated) cytoplasmic mediators such as JNK and p38 and greater nuclear translocation of NF-κB and phospho-p38 when exposed to TLR ligands. This is consistent with significantly increased expression of several inflammatory cytokines and chemokines, such as IL-6 and IL-8. These results describe how decreased TNIP1 levels promote a hyper-sensitive state in HaCaT keratinocytes evidenced by increased activation of signalling molecules downstream of TLR agonists and increased expression of pro-inflammatory mediators. TNIP1 keratinocyte deficiency as reported for some skin diseases may predispose these cells to excessive inflammatory signalling upon exposure to viral or bacterial ligands for TLR.

Loss of CNFY toxin-induced inflammation drives Yersinia pseudotuberculosis into persistency

Gastrointestinal infections caused by enteric yersiniae can become persistent and complicated by relapsing enteritis and severe autoimmune disorders. To establish a persistent infection, the bacteria have to cope with hostile surroundings when they transmigrate through the intestinal epithelium and colonize underlying gut-associated lymphatic tissues. How the bacteria gain a foothold in the face of host immune responses is poorly understood. Here, we show that the CNFY toxin, which enhances translocation of the antiphagocytic Yop effectors, induces inflammatory responses. This results in extensive tissue destruction, alteration of the intestinal microbiota and bacterial clearance. Suppression of CNFY function, however, increases interferon-γ-mediated responses, comprising non-inflammatory antimicrobial activities and tolerogenesis. This process is accompanied by a preterm reprogramming of the pathogen's transcriptional response towards persistence, which gives the bacteria a fitness edge against host responses and facilitates establishment of a commensal-type life style.

Genetic polymorphisms in TNIP1 increase the risk of gastric carcinoma

The distribution and levels of TNIP1 in malignant and normal gastric mucosa are different, but it is not known whether TNIP1 polymorphisms are related to gastric carcinogenesis. To assess the association between four TNIP1 SNPs (rs3792792, rs4958881, rs7708392, rs10036748) and carcinogenesis, we used Sequenom Mass-ARRAY technology to determine the genotypes of 302 gastric carcinoma patients and 300 healthy controls in a Northwest Chinese Han population. These data were then compared using the Chi-square test/Fisher's exact test, genetic model analysis, and haplotype analysis. Odds ratios (OR) and 95% confidence intervals (CI) were used to evaluate the correlation. We observed that patients with the "G" allele of rs7708392 and the "C" allele of rs10036748 showed an increased risk of gastric carcinoma (OR= 1.335, 95%CI: 1.021-1.745, P= 0.035; OR= 1.358, 95%CI: 1.039-1.774, P= 0.025, respectively). Conversely, the haplotype "CT" of TNIP1 (rs7708392-rs10036748) may act as a genetic protective factor for gastric carcinoma (adjusted OR= 0.731, 95%CI: 0.552-0.970, P= 0.030). Our results are the first to suggest that genetic variation in TNIP1 gene is associated with gastric carcinoma, though, this finding must be confirmed in other populations with larger sample size.

Mantle cell lymphoma in the era of precision medicine-diagnosis, biomarkers and therapeutic agents

Despite advances in the development of clinical agents for treating Mantle Cell Lymphoma (MCL), treatment of MCL remains a challenge due to complexity and frequent relapse associated with MCL. The incorporation of conventional and novel diagnostic approaches such as genomic sequencing have helped improve understanding of the pathogenesis of MCL, and have led to development of specific agents targeting signaling pathways that have recently been shown to be involved in MCL. In this review, we first provide a general overview of MCL and then discuss about the role of biomarkers in the pathogenesis, diagnosis, prognosis, and treatment for MCL. We attempt to discuss major biomarkers for MCL and highlight published and ongoing clinical trials in an effort to evaluate the dominant signaling pathways as drugable targets for treating MCL so as to determine the potential combination of drugs for both untreated and relapse/refractory cases. Our analysis indicates that incorporation of biomarkers is crucial for patient stratification and improve diagnosis and predictability of disease outcome thus help us in designing future precision therapies. The evidence indicates that a combination of conventional chemotherapeutic agents and novel drugs designed to target specific dysregulated signaling pathways can provide the effective therapeutic options for both untreated and relapse/refractory MCL.

Regulation of Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NF-κβ) in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD), encompassing both Crohn Disease (CD) and ulcerative colitis (UC) are globally prevalent diseases, impacting children of all ages. The hallmark of IBD is a perturbed immune system that leads to continuous inflammation in the gut and challenges optimal treatment. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κβ), a nuclear transcription factor, plays a major role in gut homeostasis and contributes significantly toward a balanced, homeostatic immune system. Dysregulation in the NF-κβ pathway and factors that regulate it lead to a state of uncontrolled inflammation and altered immunity, as typically observed in IBD. Levels of proinflammatory cytokines that are regulated through NF-κβ are increased in both CD and UC. Genes known to activate NF-κβ, such as, Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) and Interleukin 23 (IL-23), are associated with IBD. Factors involved in inhibition of NF-κβ, such as A20 and TOLLIP, are also affected in IBD, resulting in failed inflammation suppression/regulation. NOD-2 and A20 have specifically been found to be strongly associated with pediatric IBD. Gut commensals are known to exert anti-inflammatory activities toward NF-κβ and can have a potential role in attenuating inflammation that likely occurs due to microbial dysbiosis in IBD. Failure to terminate/downregulate NF-κβ signaling results in chronic inflammation in IBD. Well-regulated control of inflammation in children with IBD can help better control the disease and suppress immune responses. Better understanding of factors that control NF-κβ can potentially lead toward discovering targeted therapeutic interventions for IBD. Suppression of NF-κβ can be achieved through many modalities including anti-sense oligonucleotides (ASOs), siRNA (small interfering RNA), factors regulating NF-κβ, and microbes. This review focuses on the role of NF-κβ, especially in pediatric IBD, and potential therapeutic venues for attenuating NF-κβ-induced inflammation.

ABIN-1 Negatively Regulates μ-Opioid Receptor Function

The μ-opioid receptor (MOR) is a G_i/o protein-coupled receptor that mediates analgesic, euphoric, and reward effects. Using a bacterial two-hybrid screen, we reported that the carboxyl tail of the rat MOR associates with A20-binding inhibitor of nuclear factor κB (ABIN-1). This interaction was confirmed by direct protein-protein binding and coimmunoprecipitation of MOR and ABIN-1 proteins in cell lysates. Saturation binding studies showed that ABIN-1 had no effect on MOR binding. However, the interaction of ABIN-1 and MOR inhibited the activation of G proteins induced by DAMGO ([d-Ala2,N-Me-Phe4,Gly5-ol]-Enkephalin). MOR phosphorylation, ubiquitination, and internalization induced by DAMGO were decreased in Chinese hamster ovary cells that coexpressed MOR and ABIN-1. The suppression of forskolin-stimulated adenylyl cyclase by DAMGO was also inhibited by the interaction of ABIN-1 with MOR. In addition, extracellular signal-regulated kinase activation was also negatively regulated by overexpression of ABIN-1. These data suggest that ABIN-1 is a negative coregulator of MOR activation, phosphorylation, and internalization in vitro. ABIN-1 also inhibited morphine-induced hyperlocomotion in zebrafish larvae (AB strain). By utilization of an antisense morpholino oligonucleotide (MO) gene knockdown technology, the ABIN-1 MO-injected zebrafish larvae showed a significant increase (approximately 60%) in distance moved compared with control MO-injected larvae after acute morphine treatment (P < 0.01). Taken together, ABIN-1 negatively regulates MOR function in vitro and in vivo.

[Lupus nephropathy: Insight in new treatments]

Systemic lupus erythematosus is a chronic autoimmune disease. Both acquired and innate immune systems are involved in the development of this systemic disease. Lupus nephritis usually is the most serious manifestation of systemic lupus erythematosus, with significant morbidity and mortality. The physiopathological development of the renal involvement of lupus has been increasingly elucidated over the years and various target therapies have recently been developed. After some physiopathological reminders, we discuss the conventional treatment of lupus nephritis as well as the various therapeutic advances, in particular the contribution and the place of the new target therapies in the treatment of the lupus nephritis.

ABIN1 Determines Severity of Glomerulonephritis via Activation of Intrinsic Glomerular Inflammation

Transcription factor NF-κB regulates expression of numerous genes that control inflammation and is activated in glomerular cells in glomerulonephritis (GN). We previously identified genetic variants for a NF-κB regulatory, ubiquitin-binding protein ABIN1 as risk factors for GN in systemic autoimmunity. The goal was to define glomerular inflammatory events controlled by ABIN1 function in GN. Nephrotoxic serum nephritis was induced in wild-type (WT) and ubiquitin-binding deficient ABIN1[D485N] mice, and renal pathophysiology and glomerular inflammatory phenotypes were assessed. Proteinuria was also measured in ABIN1[D485N] mice transplanted with WT mouse bone marrow. Inflammatory activation of ABIN1[D472N] (D485N homolog) cultured human-derived podocytes, and interaction with primary human neutrophils were also assessed. Disruption of ABIN1 function exacerbated proteinuria, podocyte injury, glomerular NF-κB activity, glomerular expression of inflammatory mediators, and glomerular recruitment and retention of neutrophils in antibody-mediated nephritis. Transplantation of WT bone marrow did not prevent the increased proteinuria in ABIN1[D845N] mice. Tumor necrosis factor-stimulated enhanced expression and secretion of NF-κB-targeted proinflammatory mediators in ABIN1[D472N] cultured podocytes compared with WT cells. Supernatants from ABIN1[D472N] podocytes accelerated chemotaxis of human neutrophils, and ABIN1[D472N] podocytes displayed a greater susceptibility to injurious morphologic findings induced by neutrophil granule contents. These studies define a novel role for ABIN1 dysfunction and NF-κB in mediating GN through proinflammatory activation of podocytes.

TNF Tolerance in Monocytes and Macrophages: Characteristics and Molecular Mechanisms

Tumor necrosis factor (TNF) tolerance in monocytes and macrophages means that preexposure to TNF reduces the sensitivity in these cells to a subsequent restimulation with this cytokine. Differential effects arise following preincubation with both low and high doses of TNF resulting in absolute as well as induction tolerance affecting specific immunologically relevant gene sets. In this review article, we summarize the relevance of TNF tolerance in vivo and the molecular mechanisms underlying these forms of tolerance including the role of transcription factors and signaling systems. In addition, the characteristics of cross-tolerance between TNF and lipopolysaccharide (LPS) as well as pathophysiological aspects of TNF tolerance are discussed. We conclude that TNF tolerance may represent a protective mechanism involved in the termination of inflammation and preventing excessive or prolonged inflammation. Otherwise, tolerance may also be a trigger of immune paralysis thus contributing to severe inflammatory diseases such as sepsis. An improved understanding of TNF tolerance will presumably facilitate the implementation of diagnostic or therapeutic approaches to more precisely assess and treat inflammation-related diseases.

Interleukin-17 signaling triggers degradation of the constitutive NF-κB inhibitor ABIN-1

IL-17 activates NF-κB and inducing expression of proinflammatory genes. IL-17 drives disease in autoimmune conditions, and anti-IL-17 antibodies have shown impressive success in the clinic. Although produced by lymphocytes, IL-17 predominantly signals in fibroblasts and epithelial cells. IL-17-driven inflammation is kept in check by negative feedback signaling molecules, including the ubiquitin editing enzyme A20, whose gene TNFΑIP3 is and similarly linked to autoimmune disease susceptibility. Accordingly, we hypothesized that ABIN-1 might play a role in negatively regulating IL-17 signaling activity. Indeed, ABIN-1 enhanced both tonic and IL-17-dependent NF-κB signaling in IL-17-responsive fibroblast cells. Interestingly, the inhibitory activities of ABIN-1 on IL-17 signaling were independent of A20. ABIN-1 is a known NF-κB target gene, and we found that IL-17-induced activation of NF-κB led to enhanced ABIN-1 mRNA expression and promoter activity. Surprisingly, however, the ABIN-1 protein was inducibly degraded following IL-17 signaling in a proteasome-dependent manner. Thus, ABIN-1, acting independently of A20, restricts both baseline and IL-17-induced inflammatory gene expression. We conclude that IL-17-induced signals lead to degradation of ABIN-1, thereby releasing a constitutive cellular brake on NF-κB activation.

Association between TNIP1, MPHOSPH6 and ZNF208 genetic polymorphisms and the coronary artery disease risk in Chinese Han population

Introduction

Coronary artery disease (CAD) is a common disease and among the leading cause of death in the general population. Inherited factors are involved in the pathogenesis of CAD.

Aims

Our study examined whether SNPs in TNIP1, MPHOSPH6, ZNF208 to be associated with CAD risk in a Chinese Han population. We recruited 596 CAD patients, 603 controls and genotyping fifteen SNPs using Sequenom MassARRAY. For association analysis between TNIP1, MPHOSPH6 and ZNF208 and CAD was determined by Odds ratios (ORs) with 95% confidence intervals (CIs) using Logistic Regression.

Results

The results indicated in allel model, the rs960709 in TNIP1 was associated with CAD risk (OR = 0.78, 95%CI = 0.65-0.94, P=0.010). The genetic model results showed that the rs960709 (A/G) polymorphism was associated with the risk of developing CAD in codominant, Dominant and Log-additive. The rs1056654 A/A allele and CAD patients compared to the healthy controls in recessive model (OR = 0.55, 95%CI = 0.34-0.90; P = 0.018). We also found that three SNPS in ZNF208 associated with CAD, respectively, rs2188971, rs8103163 and rs7248488.

Linkage disequilibrium (LD) and haplotype analyses of the SNPs found that the CTA haplotype (rs1056675, rs1056654, rs11859599) and rs2188972A/rs2188971T/rs8103163A/rs7248488A (ATAA) were associated with CAD.

Conclusion

In conclusion, the present study provided evidence that SNPs in the TNIP1, ZNF208 and MPHOSPH6 were associated with CAD in Chinese Han population. It is possible that these SNPs are CAD risk factors and these data can provide.

Oncogenic miR-210-3p promotes prostate cancer cell EMT and bone metastasis via NF-κB signaling pathway

BACKGROUND

The primary issue arising from prostate cancer (PCa) is its high prevalence to metastasize to bone, which severely affects the quality of life and survival time of PCa patients. miR-210-3p is a well-documented oncogenic miRNA implicated in various aspects of cancer development, progression and metastasis. However, the clinical significance and biological roles of miR-210-3p in PCa bone metastasis remain obscure.

METHODS

miR-210-3p expression was evaluated by real-time PCR in 68 bone metastatic and 81 non-bone metastatic PCa tissues. The biological roles of miR-210-3p in the bone metastasis of PCa were investigated both in vitro by EMT and Transwell assays, and in vivo using a mouse model of left cardiac ventricle inoculation. Bioinformatics analysis, real-time PCR, western blot and luciferase reporter analysis were applied to discern and examine the relationship between miR-210-3p and its potential targets. RT-PCR was performed to identify the underlying mechanism of miR-210-3p overexpression in bone metastasis of PCa. Clinical correlation of miR-210-3p with its targets was examined in human PCa and metastatic bone tissues.

RESULTS

miR-210-3p expression is elevated in bone metastatic PCa tissues compared with non-bone metastatic PCa tissues. Overexpression of miR-210-3p positively correlates with serum PSA levels, Gleason grade and bone metastasis status in PCa patients. Upregulating miR-210-3p enhances, while silencing miR-210-3p represses the EMT, invasion and migration of PCa cells in vitro. Importantly, silencing miR-210-3p significantly inhibits bone metastasis of PC-3 cells in vivo. Our results further demonstrate that miR-210-3p maintains the sustained activation of NF-κB signaling via targeting negative regulators of NF-κB signaling (TNF-α Induced Protein 3 Interacting Protein 1) TNIP1 and (Suppressor Of Cytokine Signaling 1) SOCS1, resulting in EMT, invasion, migration and bone metastasis of PCa cells. Moreover, our results further indicate that recurrent gains (amplification) contribute to miR-210-3p overexpression in a small number of PCa patients. The clinical correlation of miR-210-3p with SOCS1, TNIP1 and NF-κB signaling activity is verified in PCa tissues.

CONCLUSION

Our findings unravel a novel mechanism for constitutive activation of NF-κB signaling pathway in the bone metastasis of PCa, supporting a functional and clinical significance of epigenetic events in bone metastasis of PCa.