NF-kappa B subunit-specific regulation of the interleukin-8 promoter

DDX17-Mediated Upregulation of CXCL8 Promotes Hepatocellular Carcinoma Progression via Co-activating β-catenin/NF-κB Complex

Hepatocellular carcinoma (HCC) is a well-known inflammation-related cancer, that accounts for fifth most prevalent neoplasm and the third major driver of cancer associated fatality globally. Accumulating evidence has elucidated that C-X-C motif chemokine ligands (CXCLs) are aberrantly upregulated in HCC and are involved in inflammation-induced hepatocarcinogenesis and metastasis. Herein, we identified a novel function of DEAD-box RNA helicase 17 (DDX17) as an oncogenic factor via transactivating CXCL8 in HCC. Unlike the adjacent nontumor tissues, DDX17 was highly expressed in tumor tissues compared in two independent cohorts and that it acts as an independent prognostic indicator for patients who have HCC. Mechanistically, DDX17 interacts with β-catenin and NF-κB, and promotes their nuclear translocation to promote the transcription of the inflammatory gene CXCL8, thus promoting HCC proliferation and invasion in vitro and in vivo. More interestingly, stimulation with recombinant human CXCL8 augmented the interaction of NF-κB with DDX17/β-catenin and enhanced its autocrine activation by promoting the phosphorylation of IκBα. Furthermore, blocking the association of the DDX17/β-catenin/NF-κB complex with a CXCR1/2 inhibitor markedly abrogated DDX17-mediated HCC proliferation and metastasis. Overall, this study provided new insights into DDX17-mediated pro-inflammatory chemokine activation, which unveiled the association between DDX17 and β-catenin/ NF-κB complex in transactivating the expression of CXCL8. The usage of CXCR1/2 inhibitor to block DDX17-induced CXCL8 signaling activation might be a potential therapeutic approach for HCC treatment.

NFκB and JNK pathways mediate metabolic adaptation upon ESCRT-I deficiency

Endosomal Sorting Complexes Required for Transport (ESCRTs) are crucial for delivering membrane receptors or intracellular organelles for lysosomal degradation which provides the cell with lysosome-derived nutrients. Yet, how ESCRT dysfunction affects cell metabolism remained elusive. To address this, we analyzed transcriptomes of cells lacking TSG101 or VPS28 proteins, components of ESCRT-I subcomplex. ESCRT-I deficiency reduced the expression of genes encoding enzymes involved in oxidation of fatty acids and amino acids, such as branched-chain amino acids, and increased the expression of genes encoding glycolytic enzymes. The changes in metabolic gene expression were associated with Warburg effect-like metabolic reprogramming that included intracellular accumulation of lipids, increased glucose/glutamine consumption and lactate production. Moreover, depletion of ESCRT-I components led to expansion of the ER and accumulation of small mitochondria, most of which retained proper potential and performed ATP-linked respiration. Mechanistically, the observed transcriptional reprogramming towards glycolysis in the absence of ESCRT-I occurred due to activation of the canonical NFκB and JNK signaling pathways and at least in part by perturbed lysosomal degradation. We propose that by activating the stress signaling pathways ESCRT-I deficiency leads to preferential usage of extracellular nutrients, like glucose and glutamine, for energy production instead of lysosome-derived nutrients, such as fatty acids and branched-chain amino acids.

B cell heterogeneity in human tuberculosis highlights compartment-specific phenotype and functional roles

B cells are important in tuberculosis (TB) immunity, but their role in the human lung is understudied. Here, we characterize B cells from lung tissue and matched blood of patients with TB and found they are decreased in the blood and increased in the lungs, consistent with recruitment to infected tissue, where they are located in granuloma associated lymphoid tissue. Flow cytometry and transcriptomics identify multiple B cell populations in the lung, including those associated with tissue resident memory, germinal centers, antibody secretion, proinflammatory atypical B cells, and regulatory B cells, some of which are expanded in TB disease. Additionally, TB lungs contain high levels of Mtb-reactive antibodies, specifically IgM, which promotes Mtb phagocytosis. Overall, these data reveal the presence of functionally diverse B cell subsets in the lungs of patients with TB and suggest several potential localized roles that may represent a target for interventions to promote immunity or mitigate immunopathology.

Antiviral response and immunopathogenesis of interleukin 27 in COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with a high mortality rate. The clinical course is attributed to the severity of pneumonia and systemic complications. In COVID-19 patients and murine models of SARS-CoV-2 infection, the disease may be accompanied by excessive production of cytokines, leading to an accumulation of immune cells in affected organs such as lungs. Previous reports have shown that SARS-CoV-2 infection antagonizes interferon (IFN)-dependent antiviral response, thereby preventing the expression of IFN-stimulated genes (ISGs). Lower IFN levels have been linked to more-severe COVID-19. Interleukin 27 (IL27) is a heterodimeric cytokine composed of IL27p28 and EBI3 subunits, which induce both pro- and anti-inflammatory responses. Recently, we and others have reported that IL27 also induces a strong antiviral response in an IFN-independent manner. Here, we investigated transcription levels of both IL27 subunits in COVID-19 patients. The results show that SARS-CoV-2 infection modulates TLR1/2-MyD88 signaling in PBMCs and monocytes and induces NF-κB activation and expression of NF-κB-target genes that are dependent on a robust pro-inflammatory response, including EBI3; and activates IRF1 signaling which induces IL27p28 mRNA expression. The results suggest that IL27 induces a robust STAT1-dependent pro-inflammatory and antiviral response in an IFN-independent manner in COVID-derived PBMCs and monocytes as a function of a severe clinical course of COVID-19. Similar results were observed in macrophages stimulated with the SARS-CoV-2 spike protein. Thus, IL27 can trigger an antiviral response in the host, suggesting the possibility of novel therapeutics against SARS-CoV-2 infection in humans.

Spent culture supernatant of Streptococcus gordonii mitigates inflammation of human periodontal cells and inhibits proliferation of pathogenic oral microbes

BACKGROUND

The oral commensal bacterial species Streptococcus gordonii has been reported to regulate the inflammation of oral epithelial cells stimulated by the periodontal pathogen Porphyromonas gingivalis. This study investigated the activities of S. gordonii metabolites in S. gordonii spent culture supernatants (Sg-SCS) on periodontal-related bacterial growth and periodontitis-associated inflammatory cytokines.

METHODS

Sg-SCS was collected from S. gordonii cultures grown in Dulbecco Modified Eagle Medium and added to the growth media of representative health- and disease-related oral species: S. gordonii, Streptococcus sanguinis, Streptococcus mitis, Streptococcus oralis, P. gingivalis, Tannerella forsythia, and Treponema denticola. The Sg-SCS was also tested for its ability to regulate the expression of proinflammatory cytokines by human macrophages, epithelial cells, and gingival fibroblasts upon stimulation with P. gingivalis-derived lipopolysaccharide (Pg-LPS).

RESULTS

Sg-SCS significantly reduced transcript and protein levels of interleukin (IL)-1β, 6, and 8 induced by Pg-LPS stimulation in multiple types of periodontal cells. mRNA sequencing and bioinformatics analyses indicated that Sg-SCS significantly affects 10 inflammatory pathways. Additionally, Sg-SCS exhibited suppression of the growth of periodontal disease-related bacteria, including T. denticola and P. gingivalis, along with the primary plaque-colonizing species S. oralis. At a low concentration, Sg-SCS also inhibits P. gingivalis adhesion.

CONCLUSIONS

These results strongly suggest that S. gordonii-derived SCS contains metabolites that have anti-inflammatory properties and an ability to inhibit periodontitis-associated pathogenic bacteria. Further investigation will be needed to identify the individual metabolites within the Sg-SCS to develop a novel metabolite-based approach to treating and preventing periodontitis.

RIOK3 and Its Alternatively Spliced Isoform Have Disparate Roles in the Innate Immune Response to Rift Valley Fever Virus (MP12) Infection

Rift Valley fever virus (RVFV) is a pathogenic human and livestock RNA virus that poses a significant threat to public health and biosecurity. During RVFV infection, the atypical kinase RIOK3 plays important roles in the innate immune response. Although its exact functions in innate immunity are not completely understood, RIOK3 has been shown to be necessary for mounting an antiviral interferon (IFN) response to RVFV in epithelial cells. Furthermore, after immune stimulation, the splicing pattern for RIOK3 mRNA changes markedly, and RIOK3's dominant alternatively spliced isoform, RIOK3 X2, exhibits an opposite effect on the IFN response by dampening it. Here, we further investigate the roles of RIOK3 and its spliced isoform in other innate immune responses to RVFV, namely the NFκB-mediated inflammatory response. We find that while RIOK3 is important for negatively regulating this inflammatory pathway, its alternatively spliced isoform, RIOK3 X2, stimulates it. Overall, these data demonstrate that both RIOK3 and its X2 isoform have unique roles in separate innate immune pathways that respond to RVFV infection.

Annexin-1 is an oncogene in glioblastoma and causes tumour immune escape through the indirect upregulation of interleukin-8

Annexin‐1 (ANXA1) is widely reported to be deregulated in various cancers and is involved in tumorigenesis. However, its effects on glioblastoma (GBM) remain unclear. Using immunohistochemistry with tissue microarrays, we showed that ANXA1 was overexpressed in GBM, positively correlated with higher World Health Organization (WHO) grades of glioma, and negatively associated with poor survival. To further explore its role and the underlying molecular mechanism in GBM, we constructed ANXA1shRNA U87 and U251 cell lines for further experiments. ANXA1 downregulation suppressed GBM cell proliferation, migration, and invasion and enhanced their radiosensitivity. Furthermore, we determined that ANXA1 was involved in dendritic cell (DC) maturation in patients with GBM and that DC infiltration was inversely proportional to GBM prognosis. Considering that previous reports have shown that Interleukin‐8 (IL‐8) is associated with DC migration and maturation and is correlated with NF‐κB transcriptional regulation, we examined IL‐8 and p65 subunit expressions and p65 phosphorylation levels in GBM cells under an ANXA1 knockdown. These results suggest that ANXA1 significantly promotes IL‐8 production and p65 phosphorylation levels. We inferred that ANXA1 is a potential biomarker and a candidate therapeutic target for GBM treatment and may mediate tumour immune escape through NF‐kB (p65) activation and IL‐8 upregulation.

Inflammatory gene silencing in activated monocytes by a cholesterol tagged-miRNA/siRNA: a novel approach to ameliorate diabetes induced inflammation

There is a major unmet need for the development of effective therapies for diabetes induced inflammation. Increased adenosine-uridine rich elements (AREs) containing mRNAs of inflammatory molecules are reported in inflamed monocytes. Destabilizing these inflammatory mRNAs by the miR-16 could reduce inflammation. DNA microarrays and in vitro cell studies showed that exogenous miR16 and its mimic treatment, in LPS/PMA induced monocytes, significantly downregulated several ARE containing inflammatory cytokine mRNAs similar to those seen in the normal monocytes. Ingenuity pathway analyses showed exogenous miR-16 or its synthetic mimic treatment alleviates inflammatory responses. To selectively target uptake, especially to inflamed cells, one of the CD36 substrate cholesterol was tagged to miR16/siRNA. Cholesterol tagged miR-16/ARE-siRNA showed enhanced uptake in CD36 expressing inflamed cells. In LPS or PMA, treated monocytes, candidate genes expressions levels such as IL-6, IL-8, IL-12β, IP-10, and TNF-α mRNA were increased, as measured by RT-qPCR as seen in primary monocytes of diabetes patients. Exogenous miR16 or ARE-siRNA transfection reduced mRNAs of pro-inflammatory cytokines levels in monocyte, and its adhesion. Increased uptake of cholesterol tagged miR-16 through the CD36 receptor was observed. This destabilizes numerous inflammatory ARE containing mRNAs and alleviates inflammatory responses. Cholesterol-tagged miR-16 and its mimic are novel anti-inflammatory molecules that can be specifically targeted to, via through CD36 expressing, "inflamed" cells and thus serve as therapeutic candidates to alleviate inflammatory diseases.

The Reovirus σ3 Protein Inhibits NF-κB-Dependent Antiviral Signaling

Viral antagonism of innate immune pathways is a common mechanism by which viruses evade immune surveillance. Infection of host cells with reovirus leads to the blockade of NF-κB, a key transcriptional regulator of the hosts' innate immune response. One mechanism by which reovirus infection results in inhibition of NF-κB is through a diminishment in levels of upstream activators, IKKβ and NEMO. Here, we demonstrate a second, distinct mechanism by which reovirus blocks NF-κB. We report that expression of a single viral protein, σ3, is sufficient to inhibit expression of NF-κB target genes. Further, σ3-mediated blockade of NF-κB occurs without changes to IκB kinase (IKK) levels or activity. Among NF-κB targets, the expression of type I interferon is significantly diminished by σ3 expression. Expression of NF-κB target genes varies following infection with closely related reovirus strains. Our genetic analysis identifies that these differences are controlled by polymorphisms in the amino acid sequence of σ3. This work identifies a new role for reovirus σ3 as a viral antagonist of NF-κB-dependent antiviral pathways. IMPORTANCE Host cells mount a response to curb virus replication in infected cells and prevent spread of virus to neighboring, as yet uninfected, cells. The NF-κB family of proteins is important for the cell to mediate this response. In this study, we show that a single protein, σ3, produced by mammalian reovirus, impairs the function of NF-κB. We demonstrate that by blocking NF-κB, σ3 diminishes the hosts' response to infection to promote viral replication. This work identifies a second, previously unknown, mechanism by which reovirus blocks this aspect of the host cell response.

Canonical NF-κB p65, but Not p105, Contributes to IL-1β-Induced IL-8 Expression in Cardiac Fibroblasts

Cardiac fibroblasts participate in the inflammatory process of heart diseases as sentinel cells of the cardiac tissue. In this study, we investigated the effect of the proinflammatory cytokine, interleukin 1β (IL-1β), on the expression of interleukin 8 (IL-8), which contributes to the induction of innate immunity via the activation and recruitment of innate immune cells, such as neutrophils, to the site of inflammation in canine cardiac fibroblasts. IL-1β mediates IL-8 mRNA expression and protein release in a dose- and time-dependent manner. The IL-β-mediated IL-8 protein release and mRNA expression were inhibited by 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide, an inhibitor of the transcription factor, nuclear factor (NF)-κB. In cells treated with IL-1β, NF-κB p65 and p105 were transiently phosphorylated, indicating the activation of NF-κB. However, IL-1β failed to induce IL-8 mRNA expression in the cells transfected with p65 small interfering RNA (siRNA), but not in those transfected with p105 siRNA. These observations suggest that IL-1β induces IL-8 expression via the activation of NF-κB p65 in canine cardiac fibroblasts.

SARS-CoV-2 Nsp14 mediates the effects of viral infection on the host cell transcriptome

Viral infection involves complex set of events orchestrated by multiple viral proteins. To identify functions of SARS-CoV-2 proteins, we performed transcriptomic analyses of cells expressing individual viral proteins. Expression of Nsp14, a protein involved in viral RNA replication, provoked a dramatic remodeling of the transcriptome that strongly resembled that observed following SARS-CoV-2 infection. Moreover, Nsp14 expression altered the splicing of more than 1,000 genes and resulted in a dramatic increase in the number of circRNAs, which are linked to innate immunity. These effects were independent of the Nsp14 exonuclease activity and required the N7-guanine-methyltransferase domain of the protein. Activation of the NFkB pathway and increased expression of CXCL8 occurred early upon Nsp14 expression. We identified IMPDH2, which catalyzes the rate-limiting step of guanine nucleotides biosynthesis, as a key mediator of these effects. Nsp14 expression caused an increase in GTP cellular levels, and the effect of Nsp14 was strongly decreased in presence of IMPDH2 inhibitors. Together, our data demonstrate an unknown role for Nsp14 with implications for therapy.

Synergistic Effects of Toll-Like Receptor 1/2 and Toll-Like Receptor 3 Signaling Triggering Interleukin 27 Gene Expression in Chikungunya Virus-Infected Macrophages

Chikungunya virus (CHIKV) is the etiological agent of chikungunya fever (CHIKF), a self-limiting disease characterized by myalgia and severe acute or chronic arthralgia. CHIKF is associated with immunopathology and high levels of pro-inflammatory factors. CHIKV is known to have a wide range of tropism in human cell types, including keratinocytes, fibroblasts, endothelial cells, monocytes, and macrophages. Previously, we reported that CHIKV-infected monocytes-derived macrophages (MDMs) express high levels of interleukin 27 (IL27), a heterodimeric cytokine consisting of IL27p28 and EBI3 subunits, that triggers JAK-STAT signaling and promotes pro-inflammatory and antiviral response, in interferon (IFN)-independent manner. Based on the transcriptomic analysis, we now report that induction of IL27-dependent pro-inflammatory and antiviral response in CHIKV-infected MDMs relies on two signaling pathways: an early signal dependent on recognition of CHIKV-PAMPs by TLR1/2-MyD88 to activate NF-κB-complex that induces the expression of EBI3 mRNA; and second signaling dependent on the recognition of intermediates of CHIKV replication (such as dsRNA) by TLR3-TRIF, to activate IRF1 and the induction of IL27p28 mRNA expression. Both signaling pathways were required to produce a functional IL27 protein involved in the induction of ISGs, including antiviral proteins, cytokines, CC- and CXC- chemokines in an IFN-independent manner in MDMs. Furthermore, we reported that activation of TLR4 by LPS, both in human MDMs and murine BMDM, results in the induction of both subunits of IL27 that trigger strong IL27-dependent pro-inflammatory and antiviral response independent of IFNs signaling. Our findings are a significant contribution to the understanding of molecular and cellular mechanisms of CHIKV infection.

The Immune Underpinnings of Barrett's-Associated Adenocarcinogenesis: a Retrial of Nefarious Immunologic Co-Conspirators

There is no doubt that chronic gastroesophageal reflux disease increases the risk of esophageal adenocarcinoma (EAC) by several fold (odds ratio, 6.4; 95% CI, 4.6-9.1), and some relationships between reflux disease-mediated inflammation and oncogenic processes have been explored; however, the precise interconnections between the immune response and genomic instabilities underlying these pathologic processes only now are emerging. Furthermore, the precise cell of origin of the precancerous stages associated with EAC development, Barrett's esophagus, be it cardia resident or embryonic remnant, may shape our interpretation of the likely immune drivers. This review integrates the current collective knowledge of the immunology underlying EAC development and outlines a framework connecting proinflammatory pathways, such as those mediated by interleukin 1β, tumor necrosis factor α, leukemia inhibitory factor, interleukin 6, signal transduction and activator of transcription 3, nuclear factor-κB, cyclooxygenase-2, and transforming growth factor β, with oncogenic pathways in the gastroesophageal reflux disease-Barrett's esophagus-EAC cancer sequence. Further defining these immune and molecular railroads may show a map of the routes taken by gastroesophageal cells on their journey toward EAC tumor phylogeny. The selective pressures applied by this immune-induced journey likely impact the phenotype and genotype of the resulting oncogenic destination and further exploration of lesser-defined immune drivers may be useful in future individualized therapies or enhanced selective application of recent immune-driven therapeutics.

On the Immunometabolic Role of NF-κB in Adipocytes

Two decades of research have established that Nuclear Factor-κB (NF-κB) signaling plays a critical role in reprogramming the fat cell transcriptome towards inflammation in response to overnutrition and metabolic stress. Several groups have suggested that inhibition of NF-κB signaling could have metabolic benefits for obesity-associated adipose tissue inflammation. However, two significant problems arise with this approach. The first is how to deliver general NF-κB inhibitors into adipocytes without allowing these compounds to disrupt normal functioning in cells of the immune system. The second issue is that general inhibition of canonical NF-κB signaling in adipocytes will likely lead to a massive increase in adipocyte apoptosis under conditions of metabolic stress, leading full circle into a secondary inflammation (However, this problem may not be true for non-canonical NF-κB signaling.). This review will focus on the research that has examined canonical and non-canonical NF-κB signaling in adipocytes, focusing on genetic studies that examine loss-of-function of NF-κB specifically in fat cells. Although the development of general inhibitors of canonical NF-κB signaling seems unlikely to succeed in alleviating adipose tissue inflammation in humans, the door remains open for more targeted therapeutics. In principle, these would include compounds that interrogate NF-κB DNA binding, protein-protein interactions, or post-translational modifications that partition NF-κB activity towards some genes and away from others in adipocytes. I also discuss the possibility for inhibitors of non-canonical NF-κB signaling to realize success in mitigating fat cell dysfunction in obesity. To plant the seeds for such approaches, much biochemical “digging” in adipocytes remains; this includes identifying—in an unbiased manner–NF-κB direct and indirect targets, genomic DNA binding sites for all five NF-κB subunits, NF-κB protein-protein interactions, and post-translational modifications of NF-κB in fat cells.

JNK-mediated Ser27 phosphorylation and stabilization of SIRT1 promote growth and progression of colon cancer through deacetylation-dependent activation of Snail

Sirtuin 1 (SIRT1), an NAD⁺ -dependent histone/protein deacetylase, has multifaceted functions in various biological events such as inflammation, aging, and energy metabolism. The role of SIRT1 in carcinogenesis, however, is still under debate. Recent studies have indicated that aberrant overexpression of SIRT1 is correlated with metastasis and poor prognosis in several types of malignancy, including colorectal cancer. In the present study, we found that both SIRT1 and SIRT1 phosphorylated on serine 27 were coordinately upregulated in colon cancer patients' tissues and human colon cancer cell lines. This prompted us to investigate a role of phospho-SIRT1 in the context of colon cancer progression. A phosphorylation-defective mutant form of SIRT1, in which serine 27 was substituted by alanine (SIRT1-S27A), exhibited lower protein stability compared to that of wild-type SIRT1. Notably, human colon cancer (HCT-116) cells harboring the SIRT1-S27A mutation showed decreased cell proliferation and reduced capability to form xenograft tumor in athymic nude mice, which was accompanied by diminished transcriptional activity of Snail. HCT-116 cells carrying SIRT1-S27A were less capable of deacetylating the Snail protein, with a concomitant decrease in the levels of interleukin (IL)-6 and IL-8 mRNA transcripts. Taken together, these observations suggest that SIRT1 stabilized through phosphorylation on serine 27 exerts oncogenic effects at least partly through deacetylation-dependent activation of Snail and subsequent transcription of IL-6 and IL-8 in human colon cancer cells.

VGLL3 activates inflammatory responses by inducing interleukin-1α secretion

Vestigial-like family member 3 (VGLL3), a member of the vestigial-like family, is a cofactor of the TEA-domain-containing transcription factor (TEAD). Although elevation in VGLL3 expression is associated with inflammatory diseases, such as inflammatory sarcomas and autoimmune diseases, the molecular mechanisms underlying VGLL3-mediated inflammation remain largely unknown. In this study, we analyzed the relationship between elevated VGLL3 expression and the levels of NF-κB, a transcription factor that plays a pivotal role in inflammation. NF-κB was found to be activated in a cell line stably expressing VGLL3. Mechanistically, VGLL3 was shown to promote the expression and secretion of the potent NF-κB-activating cytokine interleukin (IL)-1α, probably through its association with TEADs. As VGLL3 is a target of transforming growth factor β (TGF-β) signaling, we analyzed IL-1α induction upon TGF-β stimulation. TGF-β stimulation was observed to induce IL-1α secretion and NF-κB activation, and VGLL3 was associated with this phenomenon. The TGF-β transcription factors Smad3 and Smad4 were shown to be necessary for inducing VGLL3 and IL-1α expression. Lastly, we found that VGLL3-dependent IL-1α secretion is involved in constitutive NF-κB activation in highly malignant breast cancer cells. Collectively, the findings suggested that VGLL3 expression and TGF-β stimulation activate the inflammatory response by inducing IL-1α secretion.

ROS/TNF-α Crosstalk Triggers the Expression of IL-8 and MCP-1 in Human Monocytic THP-1 Cells via the NF-κB and ERK1/2 Mediated Signaling

IL-8/MCP-1 act as neutrophil/monocyte chemoattractants, respectively. Oxidative stress emerges as a key player in the pathophysiology of obesity. However, it remains unclear whether the TNF-α/oxidative stress interplay can trigger IL-8/MCP-1 expression and, if so, by which mechanism(s). IL-8/MCP-1 adipose expression was detected in lean, overweight, and obese individuals, 15 each, using immunohistochemistry. To detect the role of reactive oxygen species (ROS)/TNF-α synergy as a chemokine driver, THP-1 cells were stimulated with TNF-α, with/without H2O2 or hypoxia. Target gene expression was measured by qRT-PCR, proteins by flow cytometry/confocal microscopy, ROS by DCFH-DA assay, and signaling pathways by immunoblotting. IL-8/MCP-1 adipose expression was significantly higher in obese/overweight. Furthermore, IL-8/MCP-1 mRNA/protein was amplified in monocytic cells following stimulation with TNF-α in the presence of H2O2 or hypoxia (p ˂ 0.0001). Synergistic chemokine upregulation was related to the ROS levels, while pre-treatments with NAC suppressed this chemokine elevation (p ≤ 0.01). The ROS/TNF-α crosstalk involved upregulation of CHOP, ERN1, HIF1A, and NF-κB/ERK-1,2 mediated signaling. In conclusion, IL-8/MCP-1 adipose expression is elevated in obesity. Mechanistically, ROS/TNF-α crosstalk may drive expression of these chemokines in monocytic cells by inducing ER stress, HIF1A stabilization, and signaling via NF-κB/ERK-1,2. NAC had inhibitory effect on oxidative stress-driven IL-8/MCP-1 expression, which may have therapeutic significance regarding meta-inflammation.

An updated review on the role of the CXCL8-CXCR1/2 axis in the progression and metastasis of breast cancer

Chronic inflammation is a major factor in tumor growth and progression. Cancer cells secrete C-X-C chemokine ligand 8 (CXCL8) along with its receptor C-X-C chemokine receptor 1 (CXCR1) and chemokine receptor 2 (CXCR2). It plays a significant role in the activation and trafficking of inflammatory mediators, tumor proliferation and interferes in breast cancer development by controlling cell adhesion, proliferation, migration, and metastasis. This axis also plays a significant role in driving different cancers and melanomas, including breast cancer progression, by controlling stem cell masses. Few small-molecule CXCR1/2 inhibitors and CXCL8 releasing inhibitors have been identified in the past two decades that bind these receptors in their inactive forms and blocks their signaling as well as the biological activities associated with inflammation. Inhibitors of certain inflammatory molecules are projected to be more efficient in different inflammatory diseases. Preclinical trials indicate that patients may be benefitted from combined treatment with targeted drugs, chemotherapies, and immunotherapies. Thus, targeting the CXCL8-CXCR1/2 signaling axis in breast cancer could be a promising approach for its therapeutics. This review examines the roles of the CXCL8-CXCR1/2 signaling axis and how it is implicated in the tumor microenvironment in breast cancer. In addition, we also discuss the potential role of the CXCL8-CXCR1/2 axis in targeted therapeutics for breast cancer.

Deciphering the mechanisms of CC-122 resistance in DLBCL via a genome-wide CRISPR screen

CC-122 is a next-generation cereblon E3 ligase-modulating agent that has demonstrated promising clinical efficacy in patients with relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL). Mechanistically, CC-122 induces the degradation of IKZF1/3, leading to T-cell activation and robust cell-autonomous killing in DLBCL. We report a genome-wide CRISPR/Cas9 screening for CC-122 in a DLBCL cell line SU-DHL-4 with follow-up mechanistic characterization in 6 DLBCL cell lines to identify genes regulating the response to CC-122. Top-ranked CC-122 resistance genes encode, not only well-defined members or regulators of the CUL4/DDB1/RBX1/CRBN E3 ubiquitin ligase complex, but also key components of signaling and transcriptional networks that have not been shown to modulate the response to cereblon modulators. Ablation of CYLD, NFKBIA, TRAF2, or TRAF3 induces hyperactivation of the canonical and/or noncanonical NF-κB pathways and subsequently diminishes CC-122-induced apoptosis in 5 of 6 DLBCL cell lines. Depletion of KCTD5, the substrate adaptor of the CUL3/RBX1/KCTD5 ubiquitin ligase complex, promotes the stabilization of its cognate substrate, GNG5, resulting in CC-122 resistance in HT, SU-DHL-4, and WSU-DLCL2. Furthermore, knockout of AMBRA1 renders resistance to CC-122 in SU-DHL-4 and U-2932, whereas knockout of RFX7 leads to resistance specifically in SU-DHL-4. The ubiquitous and cell line-specific mechanisms of CC-122 resistance in DLBCL cell lines revealed in this work pinpoint genetic alternations that are potentially associated with clinical resistance in patients and facilitate the development of biomarker strategies for patient stratification, which may improve clinical outcomes of patients with R/R DLBCL.

Quantifying persistence in the T-cell signaling network using an optically controllable antigen receptor

T cells discriminate between healthy and infected cells with remarkable sensitivity when mounting an immune response, which is hypothesized to depend on T cells combining stimuli from multiple antigen-presenting cell interactions into a more potent response. To quantify the capacity for T cells to accomplish this, we have developed an antigen receptor that is optically tunable within cell conjugates, providing control over the duration, and intensity of intracellular T-cell signaling. We observe limited persistence within the T-cell intracellular network on disruption of receptor input, with signals dissipating entirely in ~15 min, and directly show sustained proximal receptor signaling is required to maintain gene transcription. T cells thus primarily accumulate the outputs of gene expression rather than integrate discrete intracellular signals. Engineering optical control in a clinically relevant chimeric antigen receptor (CAR), we show that this limited signal persistence can be exploited to increase CAR-T cell activation threefold using pulsatile stimulation. Our results are likely to apply more generally to the signaling dynamics of other cellular networks.

Advancement in our understanding of immune response against Encephalitozoon infection

Microsporidia are a group of obligate, intracellular, spore-forming eukaryotic pathogens, which predominantly infects immunocompromised individuals worldwide. Encephalitozoon spp. is one of the most prevalent microsporidia known to infect humans. Host immune system plays a major role in combating pathogens including Encephalitozoon spp. infecting humans. Both innate and adaptive arms of host immune system work together in combating Encephalitozoon infection. Researchers are conducting studies to elucidate the role of both arms of immune system against Encephalitozoon infection. In addition to cell-mediated adaptive immunity, role of innate immunity is also being highlighted in clearance of Encephalitozoon spp. from host body. Therefore, the current review will give a clear and consolidated update on the role of innate as well as adaptive immunity in protection against Encephalitozoon spp.

IL-33 Is Involved in the Anti-Inflammatory Effects of Butyrate and Propionate on TNFα-Activated Endothelial Cells

Short-chain fatty acids (e.g., butyrate and propionate) are able to diminish endothelial cell activation. The aim of this study was to investigate whether intracellular IL-33 mediates the effects of butyrate and propionate on TNFα-induced IL-8 production and vascular cell adhesion molecule-1 (VCAM-1) expression. In addition, it was investigated whether regulating NF-κB and MAPK signaling pathways are involved. Intracellular IL-33 was measured in human endothelial cells (HUVECs) pre-incubated for 24 h with butyrate (0.1 mM or 5 mM), propionate (0.3 mM or 10 mM), or trichostatin A (TSA, 0.5 μM) prior to TNFα (1 ng/mL) stimulation (24 h). The effects of butyrate, propionate, and TSA on TNFα-induced IL-8, vascular cell adhesion molecule-1 (VCAM-1), NF-κB, and MAPK signaling pathways in normal HUVECs and IL-33 siRNA (siIL-33)-transfected HUVECs were compared to study the role of IL-33 in the protective effects of butyrate and propionate. Endogenous IL-33 was highly expressed in the perinuclear in HUVECs, which was significantly reduced by TNFα stimulation. The TNFα-induced reduction in IL-33 was prevented by pre-incubation with butyrate or propionate. Butyrate (0.1 mM), propionate (0.3 mM), and TSA inhibited the IL-8 production and activation of NF-κB. Interestingly, this effect was not observed in siIL-33-transfected HUVECs. The effects of butyrate (5 mM), propionate (10 mM), and TSA (0.5 μM) on VCAM-1 expression and activation of MAPK signaling pathways were not affected by siIL-33 transfection. In conclusion, we showed that the inhibitory effects of butyrate and propionate on TNFα-induced IL-8 production were mediated by the HDACs/IL-33/NF-κB pathway, while their effects on VCAM-1 expression might be associated with the HDACs/MAPK signaling pathway, independently of IL-33.

The Nonstructural Protein NSs of Severe Fever with Thrombocytopenia Syndrome Virus Causes a Cytokine Storm through the Hyperactivation of NF-κB

Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging highly pathogenic phlebovirus. The syndrome is characterized by the substantial production of inflammatory cytokines and chemokines, described as a cytokine storm, which correlates with multiorgan failure and high mortality. SFSTV nonstructural (NSs) protein was suggested to mediate the pathogenesis by inhibiting antiviral interferon signaling in the host. However, whether SFTSV NSs protein mediates the induction of a fatal cytokine storm remains unaddressed. We demonstrated that SFTSV NSs promotes the hyperinduction of cytokine/chemokine genes in vitro, reminiscent of a cytokine storm. Using gene deletion and pharmacological intervention, we found that the induced cytokine storm is driven by the transcription factor NF-κB. Our investigation revealed that TANK-binding kinase 1 (TBK1) suppresses NF-κB signaling and cytokine/chemokine induction in a kinase activity-dependent manner and that NSs sequesters TBK1 to prevent it from suppressing NF-κB, thereby promoting the activation of NF-κB and its target cytokine/chemokine genes. Of note, NF-κB inhibition suppressed the induction of proinflammatory cytokines in SFTSV-infected type I interferon (IFN-I) receptor 1-deficient (Ifnar1^-/-) mice. These findings establish the essential role of NSs in SFTS pathogenesis and suggest NF-κB as a possible therapeutic target.

Administration of N-acetylcysteine Plus Acetylsalicylic Acid Markedly Inhibits Nicotine Reinstatement Following Chronic Oral Nicotine Intake in Female Rats

Background

Nicotine is the major addictive component of cigarette smoke and the prime culprit of the failure to quit smoking. Common elements perpetuating the use of addictive drugs are (i) cues associated with the setting in which drug was used and (ii) relapse/reinstatement mediated by an increased glutamatergic tone (iii) associated with drug-induced neuroinflammation and oxidative stress.

Aims

The present study assessed the effect of the coadministration of the antioxidant N-acetylcysteine (NAC) plus the anti-inflammatory acetylsalicylic acid (ASA) on oral nicotine reinstatement intake following a post-deprivation re-access in female rats that had chronically and voluntarily consumed a nicotine solution orally. The nicotine-induced oxidative stress and neuroinflammation in the hippocampus and its effects on the glutamate transporters GLT-1 and XCT mRNA levels in prefrontal cortex were also analyzed.

Results

The oral coadministration of NAC (40 mg/kg/day) and ASA (15 mg/kg/day) inhibited by 85% of the oral nicotine reinstatement intake compared to control (vehicle), showing an additive effect of both drugs. Acetylsalicylic acid and N-acetylcysteine normalized hippocampal oxidative stress and blunted the hippocampal neuroinflammation observed upon oral nicotine reinstatement. Nicotine downregulated GLT-1 and xCT gene expression in the prefrontal cortex, an effect reversed by N-acetylcysteine, while acetylsalicylic acid reversed the nicotine-induced downregulation of GLT-1 gene expression. The inhibitory effect of N-acetylcysteine on chronic nicotine intake was blocked by the administration of sulfasalazine, an inhibitor of the xCT transporter.

Conclusion

Nicotine reinstatement, following post-deprivation of chronic oral nicotine intake, downregulates the mRNA levels of GLT-1 and xCT transporters, an effect reversed by the coadministration of N-acetylcysteine and acetylsalicylic acid, leading to a marked inhibition of nicotine intake. The combination of these drugs may constitute a valuable adjunct in the treatment of nicotine-dependent behaviors.

Identification of a Selective RelA Inhibitor Based on DSE-FRET Screening Methods

Nuclear factor-κB (NF-κB) is an important transcription factor involved in various biological functions, including tumorigenesis. Hence, NF-κB has attracted attention as a target factor for cancer treatment, leading to the development of several inhibitors. However, existing NF-κB inhibitors do not discriminate between its subunits, namely, RelA, RelB, cRel, p50, and p52. Conventional methods used to evaluate interactions between transcription factors and DNA, such as electrophoretic mobility shift assay and luciferase assays, are unsuitable for high-throughput screening (HTS) and cannot distinguish NF-κB subunits. We developed a HTS method named DNA strand exchange fluorescence resonance energy transfer (DSE-FRET). This assay is suitable for HTS and can discriminate a NF-κB subunit. Using DSE-FRET, we searched for RelA-specific inhibitors and verified RelA inhibition for 32,955 compounds. The compound A55 (2-(3-carbamoyl-6-hydroxy-4-methyl-2-oxopyridin-1(2H)-yl) acetic acid) selectively inhibited RelA–DNA binding. We propose that A55 is a seed compound for RelA-specific inhibition and could be used in clinical applications.

IL-1α released from oral epithelial cells upon candidalysin exposure initiates an early innate epithelial response

Candida albicans is a commensal fungus that predominantly resides on mucosal surfaces and can cause lethal systemic infection when the host defense is compromised. Candidalysin is a cytolytic peptide toxin produced by C. albicans hyphae that is essential for mucosal tissue damage and is believed to contribute to the establishment of systemic infection and mortality. Candidalysin is also required for the epithelial innate response in which proinflammatory cytokines and chemokines are produced and neutrophil recruitment is initiated. It was recently reported that epidermal growth factor receptor (EGFR) was essential for the candidalysin-triggered epithelial response. The present study identified IL-1α as another component of candidalysin-mediated initial epithelial activation. We found that human oral epithelial cells released IL-1α rapidly after candidalysin exposure. Blockade of IL-1α/IL-1 receptor (IL-1R) signaling in candidalysin-exposed cells resulted in decreased phosphorylation of IκBα, decreased induction of IκBζ and decreased production of granulocyte-macrophage colony-stimulating factor and IL-8. Expression of c-Fos, which is induced downstream of EGFR signaling in candidalysin-treated cells, is less affected by IL-1R blockade. Inversely, blockade of EGFR signaling does not affect candidalysin-mediated phosphorylation of IκBα and induction of IκBζ, suggesting that independent signaling pathways contribute to the induction of NF-κB and c-Fos downstream of the candidalysin pore formation site. Consistently, antibody inhibition of both EGFR and IL-1R enhanced the suppressive effect of cytokine production in candidalysin-treated cells. Thus, we identified the immediate release of IL-1α and its synergistic role with EGFR ligands on the initial activation of oral epithelial cells in response to candidalysin.

Comparative Characterization of Two cxcl8 Homologs in Oplegnathus fasciatus: Genomic, Transcriptional and Functional Analyses

CXCL8 (interleukin-8, IL-8) is a CXC family chemokine that recruits specific target cells and mediates inflammation and wound healing. This study reports the identification and characterization of two cxcl8 homologs from rock bream, Oplegnathus fasciatus. Investigation of molecular signature, homology, phylogeny, and gene structure suggested that they belonged to lineages 1 (L1) and 3 (L3), and designated Ofcxcl8-L1 and Ofcxcl8-L3. While Ofcxcl8-L1 and Ofcxcl8-L3 revealed quadripartite and tripartite organization, in place of the mammalian ELR (Glu-Leu-Arg) motif, their peptides harbored EMH (Glu-Met-His) and NSH (Asn-Ser-His) motifs, respectively. Transcripts of Ofcxcl8s were constitutively detected by Quantitative Real-Time PCR (qPCR) in 11 tissues examined, however, at different levels. Ofcxcl8-L1 transcript robustly responded to treatments with stimulants, such as flagellin, concanavalin A, lipopolysaccharide, and poly(I:C), and pathogens, including Edwardsiella tarda, Streptococcus iniae, and rock bream iridovirus, when compared with Ofcxcl8-L3 mRNA. The differences in the putative promoter features may partly explain the differential transcriptional modulation of Ofcxcl8s. Purified recombinant OfCXCL8 (rOfCXCL8) proteins were used in in vitro chemotaxis and proliferation assays. Despite the lack of ELR motif, both rOfCXCL8s exhibited leukocyte chemotactic and proliferative functions, where the potency of rOfCXCL8-L1 was robust and significant compared to that of rOfCXCL8-L3. The results, taken together, are indicative of the crucial importance of Ofcxcl8s in inflammatory responses and immunoregulatory roles in rock bream immunity.

Cytotrophoblast extracellular vesicles enhance decidual cell secretion of immune modulators via TNFα

The placenta releases large quantities of extracellular vesicles (EVs) that likely facilitate communication between the embryo/fetus and the mother. We isolated EVs from second trimester human cytotrophoblasts (CTBs) by differential ultracentrifugation and characterized them using transmission electron microscopy, immunoblotting and mass spectrometry. The 100,000  g pellet was enriched for vesicles with a cup-like morphology typical of exosomes. They expressed markers specific to this vesicle type, CD9 and HRS, and the trophoblast proteins placental alkaline phosphatase and HLA-G. Global profiling by mass spectrometry showed that placental EVs were enriched for proteins that function in transport and viral processes. A cytokine array revealed that the CTB 100,000  g pellet contained a significant amount of tumor necrosis factor α (TNFα). CTB EVs increased decidual stromal cell (dESF) transcription and secretion of NF-κB targets, including IL8, as measured by qRT-PCR and cytokine array. A soluble form of the TNFα receptor inhibited the ability of CTB 100,000  g EVs to increase dESF secretion of IL8. Overall, the data suggest that CTB EVs enhance decidual cell release of inflammatory cytokines, which we theorize is an important component of successful pregnancy.

Regional, cellular and species difference of two key neuroinflammatory genes implicated in schizophrenia

The transcription factor nuclear factor kappa B (NF-κB) regulates the expression of many inflammatory genes that are overexpressed in a subset of people with schizophrenia. Transcriptional reduction in one NF-κB inhibitor, Human Immunodeficiency Virus Enhancer Binding Protein 2 (HIVEP2), is found in the brain of patients, aligning with evidence of NF-κB over-activity. Cellular co-expression of HIVEP2 and cytokine transcripts is a prerequisite for a direct effect of HIVEP2 on pro-inflammatory transcription, and we do not know if changes in HIVEP2 and markers of neuroinflammation are occurring in the same brain cell type. We performed in situ hybridisation on postmortem dorsolateral prefrontal cortex tissue to map and compare the expression of HIVEP2 and Serpin Family A Member 3 (SERPINA3), one of the most consistently increased inflammatory genes in schizophrenia, between schizophrenia patients and controls. We find that HIVEP2 expression is neuronal and is decreased in almost all grey matter cortical layers in schizophrenia patients with neuroinflammation, and that SERPINA3 is increased in the dorsolateral prefrontal cortex grey matter and white matter in the same group of patients. We are the first to map the upregulation of SERPINA3 to astrocytes and to some neurons, and find evidence to suggest that blood vessel-associated astrocytes are the main cellular source of SERPINA3 in the schizophrenia cortex. We show that a lack of HIVEP2 in mice does not cause astrocytic upregulation of Serpina3n but does induce its transcription in neurons. We speculate that HIVEP2 downregulation is not a direct cause of astrocytic pro-inflammatory cytokine synthesis in schizophrenia but may contribute to neuronally-mediated neuroinflammation.

Phosphorylation of steroid receptor coactivator-3 (SRC-3) at serine 857 is regulated by the p38MAPK-MK2 axis and affects NF-κB-mediated transcription

Steroid receptor coactivator-3 (SRC-3) regulates the activity of both nuclear hormone receptors and a number of key transcription factors. It is implicated in the regulation of cell proliferation, inflammation and in the progression of several common cancers including breast, colorectal and lung tumors. Phosphorylation is an important regulatory event controlling the activities of SRC-3. Serine 857 is the most studied phospho-acceptor site, and its modification has been reported to be important for SRC-3-dependent tumor progression. In this study, we show that the stress-responsive p38MAPK-MK2 signaling pathway controls the phosphorylation of SRC-3 at S857 in a wide range of human cancer cells. Activation of the p38MAPK-MK2 pathway results in the nuclear translocation of SRC-3, where it contributes to the transactivation of NF-kB and thus regulation of IL-6 transcription. The identification of the p38MAPK-MK2 signaling axis as a key regulator of SRC-3 phosphorylation and activity opens up new possibilities for the development and testing of novel therapeutic strategies to control both proliferative and metastatic tumor growth.

Crosstalk between Akt and NF-κB pathway mediates inhibitory effect of gas6 on monocytes-endothelial cells interactions stimulated by P. gingivalis-LPS

Correlation between periodontitis and atherosclerosis is well established, and the inherent mechanisms responsible for this relationship remain unclear. The biological function of growth arrest‐specific 6 (gas6) has been discovered in both atherosclerosis and inflammation. Inhibitory effects of gas6 on the expression of inflammatory factors in human umbilical vein endothelial cells (HUVECs) stimulated by Porphyromonas gingivalis lipopolysaccharide (P. gingivalis‐LPS) were reported in our previous research. Herein, the effects of gas6 on monocytes‐endothelial cells interactions in vitro and their probable mechanisms were further investigated. Gas6 protein in HUVECs was knocked down with siRNA or overexpressed with plasmids. Transwell inserts and co‐culturing system were introduced to observe chemotaxis and adhering affinity between monocytes and endothelial cells in vitro. Expression of gas6 was decreased in inflammatory periodontal tissues and HUVECs challenged with P. gingivalis‐LPS. The inhibitory effect of gas6 on chemotaxis and adhesion affinity between monocytes and endothelial cells was observed, and gas6 promoted Akt phosphorylation and inhibited NF‐κB phosphorylation. To our best knowledge, we are first to report that gas6 inhibit monocytes‐endothelial cells interactions in vitro induced by P. gingivalis‐LPS via Akt/NF‐κB pathway. Additionally, inflammation‐mediated inhibition of gas6 expression is through LncRNA GAS6‐AS2, rather than GAS6‐AS1, which is also newly reported.

Human monocytes subjected to ischaemia/reperfusion inhibit angiogenesis and wound healing in vitro

OBJECTIVES

The sequence of initial tissue ischaemia and consecutive blood flow restoration leads to ischaemia/reperfusion (I/R) injury, which is typically characterized by a specific inflammatory response. Migrating monocytes seem to mediate the immune response in ischaemic tissues and influence detrimental as well as regenerative effects during I/R injury.

MATERIALS AND METHODS

To clarify the role of classical monocytes in I/R injury, isolated human monocytes were subjected to I/R in vitro (3 hours ischaemia followed by 24 hours of reperfusion). Cellular resilience, monocyte differentiation, cytokine secretion, as well as influence on endothelial tube formation, migration and cell recovery were investigated.

RESULTS

We show that I/R supported an enhanced resilience of monocytes and induced intracellular phosphorylation of the prosurvival molecules Erk1/2 and Akt. FACS analysis showed no major alteration in monocyte subtype differentiation and surface marker expression under I/R. Further, our experiments revealed that I/R changes the cytokine secretion pattern, release of angiogenesis associated proteins and MMP-9 activity in supernatants of monocytes exposed to I/R. Supernatants from monocytes subjected to I/R attenuated endothelial tube formation as indicator for angiogenesis as well as endothelial cell migration and recovery.

CONCLUSION

In summary, monocytes showed no significant change in cellular integrity and monocyte subtype after I/R. Functionally, monocytes might have a rather detrimental influence during the initial phase of I/R, suppressing endothelial cell migration and neoangiogenesis.

A pilot study of biomarkers of oxidative stress in serum and schizophrenia

Increasing evidence indicates that oxidative damage and inflammation is present in patients with schizophrenia. In this study, we investigated the association between the serum concentrations of four typical oxidative stress and inflammatory biomarkers (monocyte chemotactic protein-1, heme oxygenase-1, interleukin-8, and 8-Hydroxydeoxyguanine) and schizophrenia using a case-control study design. In total, 44 patients with schizophrenia and 45 normal controls from Shandong Province, China were recruited. Fasting blood samples were collected from all participants and the serum concentration of the four biomarkers were analyzed by Enzyme-linked immunosorbent assay. The concentrations of monocyte chemotactic protein-1 and interleukin-8 were significantly higher in the patients than in the controls, while there was no significant difference in the serum concentrations of heme oxygenase-1 and 8-Hydroxydeoxyguanine. Moreover, the serum concentrations of monocyte chemotactic protein-1 and interleukin-8 in patients were positively correlated with severity of clinical symptoms. Dose-response relationships between serum biomarker concentrations and schizophrenia were observed. This study suggests that levels of monocyte chemotactic protein-1 and interleukin-8 are increased in patients with schizophrenia and correlated with positive symptom severity.

Cancer-associated V-ATPase induces delayed apoptosis of protumorigenic neutrophils

Tumors and neutrophils undergo an unexpected interaction, in which products released by tumor cells interact to support neutrophils that in turn support cancer growth, angiogenesis, and metastasis. A key protein that is highly expressed by cancer cells in tumors is the a2 isoform V‐ATPase (a2V). A peptide from a2V (a2NTD) is secreted specifically by cancer cells, but not normal cells, into the tumor microenvironment. This peptide reprograms neutrophils to promote angiogenesis, cancer cell invasiveness, and neutrophil recruitment. Here, we provide evidence that cancer‐associated a2V regulates the life span of protumorigenic neutrophils by influencing the intrinsic pathway of apoptosis. Immunohistochemical analysis of human cancer tissue sections collected from four different organs shows that levels of a2NTD and neutrophil counts are increased in cancer compared with normal tissues. Significant increases in neutrophil counts were present in both poorly and moderately differentiated tumors. In addition, there is a positive correlation between the number of neutrophils and a2NTD expression. Human neutrophils treated with recombinant a2NTD show significantly delayed apoptosis, and such prolonged survival was dependent on NF‐κB activation and ROS generation. Induction of antiapoptotic protein expression (Bcl‐xL and Bcl‐2A1) and decreased expression of proapoptotic proteins (Bax, Apaf‐1, caspase‐3, caspase‐6, and caspase‐7) were a hallmark of these treated neutrophils. Autocrine secretion of prosurvival cytokines of TNF‐α and IL‐8 by treated neutrophils prolongs their survival. Our findings highlight the important role of cancer‐associated a2V in regulating protumorigenic innate immunity, identifying a2V as a potential important target for cancer therapy.

The Role of Chemokine Receptors in Renal Fibrosis

Renal fibrosis is the final pathological process common to any ongoing, chronic kidney injury or maladaptive repair. Renal fibrosis is considered to be closely related to various cell types, such as fibroblasts, myofibroblasts, T cells, and other inflammatory cells. Multiple types of cells regulate renal fibrosis through the recruitment, proliferation, and activation of fibroblasts, and the production of the extracellular matrix. Cell trafficking is orchestrated by a family of small proteins called chemokines. Chemokines are cytokines with chemotactic properties, which are classified into 4 groups: CXCL, CCL, CX3CL, and XCL. Similarly, chemokine receptors are G protein-coupled seven-transmembrane receptors classified into 4 groups: XCR, CCR, CXCR, and CX3CR. Chemokine receptors are also implicated in the infiltration, differentiation, and survival of functional cells, triggering inflammation that leads to fibrosis development. In this review, we summarize the different chemokine receptors involved in the processes of fibrosis in different cell types. Further studies are required to identify the molecular mechanisms of chemokine signaling that contribute to renal fibrosis.

CXCR4 and CXCR3 are two distinct prognostic biomarkers in breast cancer: Database mining for CXCR family members

CXC chemokine receptors (CXCRs) and chemokines are involved in tissue development and homeostasis, including in cancer development and progression. To date, seven CXCRs have been identified. However, the expression of CXCRs and their influence on the occurrence and development of breast cancer (BC) requires further investigation. In the present study, mRNA expression levels of the seven CXCRs were compared between normal tissues and several cancer types using the Oncomine database. Highly expressed CXCRs were selected and the expression levels of these CXCRs were examined in different subtypes of BC using the Gene Expression-Based Outcome for Breast Cancer database. Finally, the prognostic value of these CXCRs was examined using Kaplan-Meier plotter. It was found that, compared with normal controls, transcripts of CXCR4 and CXCR3 were significantly overexpressed in BC samples compared with other CXCRs. Survival analysis showed that high expression of CXCR4 promoted the recurrence of BC but had no impact on overall survival (OS), while a high level of CXCR3 transcript expression was significantly associated with increased survival in patients with BC. With regards to different subtypes of BC, the present study revealed that high CXCR4 transcript expression was significantly associated with both longer relapse-free survival and OS only in basal-like BC. Furthermore, CXCR4 promoted chemosensitivity in patients with basal-like BC and induced resistance against endocrine therapy for patients with luminal A BC. Thus, CXCR4 and CXCR3 are two distinct prognostic biomarkers and further studies are required.

Control of growth factor signalling by MACPF proteins

Members of the membrane attack complex/perforin-like (MACPF) protein superfamily have long captured interest because of their unique ability to assemble into large oligomeric pores on the surfaces of cells. The best characterised of these act in vertebrate immunity where they function to deliver pro-apoptotic factors or induce the cytolysis and death of targeted cells. Less appreciated, however, is that rather than causing cell death, MACPF proteins have also evolved to control cellular signalling pathways and influence developmental programmes such as pattern formation and neurogenesis. Torso-like (Tsl) from the fruit fly Drosophila, for example, functions to localise the activity of a growth factor for patterning its embryonic termini. It remains unclear whether these developmental proteins employ an attenuated form of the classical MACPF lytic pore, or if they have evolved to function via alternative mechanisms of action. In this minireview, we examine the evidence that links pore-forming MACPF proteins to the control of growth factor and cytokine signalling. We will then attempt to reconcile how the MACPF domain may have been repurposed during evolution for developmental events rather than cell killing.

Proliferative Pathways of Vascular Smooth Muscle Cells in Response to Intermittent Hypoxia

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH) and is a risk factor for cardiovascular diseases (e.g., atherosclerosis) and chronic inflammatory diseases (CID). The excessive proliferation of vascular smooth muscle cells (VSMCs) plays a pivotal role in the progression of atherosclerosis. Hypoxia-inducible factor-1 and nuclear factor-κB are thought to be the main factors involved in responses to IH and in regulating adaptations or inflammation pathways, however, further evidence is needed to demonstrate the underlying mechanisms of this process in VSMCs. Furthermore, few studies of IH have examined smooth muscle cell responses. Our previous studies demonstrated that increased interleukin (IL)-6, epidermal growth factor family ligands, and erbB2 receptor, some of which amplify inflammation and, consequently, induce CID, were induced by IH and were involved in the proliferation of VSMCs. Since IH increased IL-6 and epiregulin expression in VSMCs, the same phenomenon may also occur in other smooth muscle cells, and, consequently, may be related to the incidence or progression of several diseases. In the present review, we describe how IH can induce the excessive proliferation of VSMCs and we develop the suggestion that other CID may be related to the effects of IH on other smooth muscle cells.

Loss of zinc-finger protein 143 contributes to tumour progression by interleukin-8-CXCR axis in colon cancer

Several studies have shown that expression of zinc‐finger protein 143 (ZNF143) is closely related to tumour progression including colon cancer. However, it remains unclear how ZNF143 expression is related to tumour progression within the tumour microenvironment. Here, we investigated whether ZNF143 expression affects the tumour microenvironment and tumour progression by screening molecules secreted by colon cancer cells stably expressing short‐hairpin RNAs against ZNF143 or control RNAs. We observed that secretion of interleukin (IL)‐8 was increased when ZNF143 expression was reduced in two colon cancer cell lines. The mRNA and protein levels of IL‐8 were increased in cells following ZNF143 knockdown, and this effect was reversed when ZNF143 expression was restored. The Janus tyrosine kinase/signal transducer and activator of transcription (JAK/STAT) and extracellular signal‐regulated kinase pathways were also shown to contribute to IL‐8 expression in ZNF143‐knockdown cells. The expression levels of ZNF143 and IL‐8 were inversely correlated with three‐dimensionally grown spheroids and colon cancer tissues. THP‐1 cells were differentiated when cells were incubated with condition media from colon cancer cell with less ZNF143, drastically. Loss of ZNF143 may contribute to the development of colon cancer by regulating intracellular and intercellular signalling for cell plasticity and the tumour microenvironment respectively.

Amorphous Silica Nanoparticles Obtained by Laser Ablation Induce Inflammatory Response in Human Lung Fibroblasts

Silica nanoparticles (SiO₂ NPs) represent environmentally born nanomaterials that are used in multiple biomedical applications. Our aim was to study the amorphous SiO₂ NP-induced inflammatory response in MRC-5 human lung fibroblasts up to 72 hours of exposure. The intracellular distribution of SiO₂ NPs was measured by transmission electron microscopy (TEM). The lactate dehydrogenase (LDH) test was used for cellular viability evaluation. We have also investigated the lysosomes formation, protein expression of interleukins (IL-1β, IL-2, IL-6, IL-8, and IL-18), COX-2, Nrf2, TNF-α, and nitric oxide (NO) production. Our results showed that the level of lysosomes increased in time after exposure to the SiO₂ NPs. The expressions of interleukins and COX-2 were upregulated, whereas the expressions and activities of MMP-2 and MMP-9 decreased in a time-dependent manner. Our findings demonstrated that the exposure of MRC-5 cells to 62.5 µg/mL of SiO₂ NPs induced an inflammatory response.

Targeting Oncogenic Nuclear Factor Kappa B Signaling with Redox-Active Agents for Cancer Treatment

SIGNIFICANCE

Nuclear factor kappa B (NF-κB) signaling is essential under physiologically relevant conditions. However, aberrant activation of this pathway plays a pertinent role in tumorigenesis and contributes to resistance. Recent Advances: The importance of the NF-κB pathway means that its targeting must be specific to avoid side effects. For many currently used therapeutics and those under development, the ability to generate reactive oxygen species (ROS) is a promising strategy.

CRITICAL ISSUES

As cancer cells exhibit greater ROS levels than their normal counterparts, they are more sensitive to additional ROS, which may be a potential therapeutic niche. It is known that ROS are involved in (i) the activation of NF-κB signaling, when in sublethal amounts; and (ii) high levels induce cytotoxicity resulting in apoptosis. Indeed, ROS-induced cytotoxicity is valuable for its capabilities in killing cancer cells, but establishing the potency of ROS for effective inhibition of NF-κB signaling is necessary. Indeed, some cancer treatments, currently used, activate NF-κB and may stimulate oncogenesis and confer resistance.

FUTURE DIRECTIONS

Thus, combinatorial approaches using ROS-generating agents alongside conventional therapeutics may prove an effective tactic to reduce NF-κB activity to kill cancer cells. One strategy is the use of thiosemicarbazones, which form redox-active metal complexes that generate high ROS levels to deliver potent antitumor activity. These agents also upregulate the metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), which functions as an NF-κB signaling inhibitor. It is proposed that targeting NF-κB signaling may proffer a new therapeutic niche to improve the efficacy of anticancer regimens.

Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis

The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses.

Phosphothreonine Lyase Promotes p65 Degradation in a Mitogen-Activated Protein Kinase/Mitogen- and Stress-Activated Protein Kinase 1-Dependent Manner

Bacterial phosphothreonine lyases have been identified to be type III secretion system (T3SS) effectors that irreversibly dephosphorylate host mitogen-activated protein kinase (MAPK) signaling to promote infection. However, the effects of phosphothreonine lyase on nuclear factor κB (NF-κB) signaling remain largely unknown. In this study, we detected significant phosphothreonine lyase-dependent p65 degradation during Edwardsiella piscicida infection in macrophages, and this degradative effect was blocked by the protease inhibitor MG132. Further analysis revealed that phosphothreonine lyase promotes the dephosphorylation and ubiquitination of p65 by inhibiting the phosphorylation of mitogen- and stress-activated protein kinase-1 (MSK1) and by inhibiting the phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2), p38α, and c-Jun N-terminal kinase (JNK). Moreover, we revealed that the catalytic active site of phosphothreonine lyase plays a critical role in regulating the MAPK-MSK1-p65 signaling axis. Collectively, the mechanism described here expands our understanding of the pathogenic effector in not only regulating MAPK signaling but also regulating p65. These findings uncover a new mechanism by which pathogenic bacteria overcome host innate immunity to promote pathogenesis.

Dynamic protein expression of NF-κB following rat intracerebral hemorrhage and its association with apoptosis

The aim of the present study was to evaluate the dynamic protein expression of nuclear factor (NF)-κB and apoptosis in the cerebral tissue surrounding hematoma following intracerebral hemorrhage (ICH) in rats. A total of 80 healthy male Wistar rats were divided into a sham-surgery group and an ICH group. The ICH model was established by injecting autogenous non-heparin anticoagulant arterial blood into the caudate putamen. NF-κB levels were assessed by immunohistochemistry at different time points subsequent to surgery, and apoptosis condition was investigated by terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling. Different levels of NF-κB were expressed in the cerebral tissue around the ICH at each time point in the ICH group. NF-κB protein expression was detected at 3 h following hemorrhage, mainly in the cytoplasm. Following 6 h, NF-κB was identified in the nucleus. Its expression peaked at 72 h following hemorrhage, and persisted for 5 days. Apoptosis was observed 6 h following hemorrhage, and had increased significantly by 12 h. The rate of apoptosis continued to rise from 72-120 h following hemorrhage. Correlation analysis revealed a significant positive correlation between NF-κB expression and apoptosis (r=0.753; P<0.01). The enhancement of NF-κB expression and apoptosis around ICH, and the significant positive correlation between NF-κB expression and apoptosis, indicates that NF-κB activation may enhance cerebral apoptosis in rats following ICH.

Proteasome inhibition induces IKK-dependent interleukin-8 expression in triple negative breast cancer cells: Opportunity for combination therapy

Triple negative breast cancer (TNBC) cells express increased levels of the pro-inflammatory and pro-angiogenic chemokine interleukin-8 (IL-8, CXCL8), which promotes their proliferation and migration. Because TNBC patients are unresponsive to current targeted therapies, new therapeutic strategies are urgently needed. While proteasome inhibition by bortezomib (BZ) or carfilzomib (CZ) has been effective in treating hematological malignancies, it has been less effective in solid tumors, including TNBC, but the mechanisms are incompletely understood. Here we report that proteasome inhibition significantly increases expression of IL-8, and its receptors CXCR1 and CXCR2, in TNBC cells. Suppression or neutralization of the BZ-induced IL-8 potentiates the BZ cytotoxic and anti-proliferative effect in TNBC cells. The IL-8 expression induced by proteasome inhibition in TNBC cells is mediated by IκB kinase (IKK), increased nuclear accumulation of p65 NFκB, and by IKK-dependent p65 recruitment to IL-8 promoter. Importantly, inhibition of IKK activity significantly decreases proliferation, migration, and invasion of BZ-treated TNBC cells. These data provide the first evidence demonstrating that proteasome inhibition increases the IL-8 signaling in TNBC cells, and suggesting that IKK inhibitors may increase effectiveness of proteasome inhibitors in treating TNBC.

An NFκB-dependent mechanism of tumor cell plasticity and lateral transmission of aggressive features

Breast cancer is a complex disease exhibiting extensive inter- and intra-tumor heterogeneity. Inflammation is a well-known driver of cancer progression, often attributed to immune cells infiltrating the tumor stroma. However, tumor cells themselves are capable to secrete a variety of inflammatory molecules, of which we understand very little about their role in intra-clonal communication. We recently reported the capacity of triple negative cell lines to induce a cancer stem cell (CSC)-like phenotype and invasion properties into luminal cells, a mechanism mediated by pro-inflammatory cytokines that up-regulated the CXCL12/CXCR4/CXCR7 chemokine signaling axis. We performed transcriptional array analyses of CSCs-associated genes and cancer-inflammatory cell crosstalk genes and built regulatory networks with the data collected. We found a specific molecular signature segregating with the induced-invasive/stemness phenotype. Regulatory network analysis pointed out to an NFκB transcriptional signature, active in aggressive triple negative cells and in induced-invasive/CSC-like luminal cells. In agreement, NFκB inhibition abolished the induction of the stemness/invasive features. These data support an NFκB dependent mechanism of intra-clonal communication responsible for tumor cell plasticity leading the acquisition of cancer aggressive features. Understanding the communication between different tumor clones would help to find better therapeutic and prophylactic targets to prevent BrC progression and relapse.