IL-6 Promoter Research Articles

Jagged-Notch-mediated divergence of immune cell crosstalk maintains the anti-inflammatory response in visceral leishmaniasis.

Notch signaling governs crucial aspects of intercellular communication spanning antigen-presenting cells and T-cells. In this study, we investigate how Leishmaniadonovani takes advantage of this pathway to quell host immune responses. We report induction of the Notch ligand Jagged1 in L. donovani-infected bone marrow macrophages (BMMϕs) and subsequent activation of RBPJκ (also known as RBPJ) in T cells, which in turn upregulates the transcription factor GATA3. Activated RBPJκ also associates with the histone acetyltransferase p300 (also known as EP300), which binds with the Bcl2l12 promoter and enhances its expression. Interaction of Bcl2L12 with GATA3 in CD4+ T cells facilitates its binding to the interleukin (IL)-10 and IL-4 promoters, thereby increasing the secretion of these cytokines. Silencing Jagged1 hindered these events in a BMMϕ-T cell co-culture system. Upon further scrutiny, we found that parasite lipophosphoglycan (LPG) induces the host phosphoinositide 3-kinase (PI3K)/Akt pathway, which activates β-catenin and Egr1, the two transcription factors responsible for driving Jagged1 expression. In vivo morpholino-silencing of Jagged1 suppresses anti-inflammatory cytokine responses and reduces organ parasite burden in L. donovani-infected Balb/c mice, suggesting that L. donovani-induced host Jagged1-Notch signaling skews macrophage-T cell crosstalk into disease-promoting Th2 mode in experimental visceral leishmaniasis.This article has an associated First Person interview with the first author of the paper.

KLHDC7B-DT aggravates pancreatic ductal adenocarcinoma development via inducing cross-talk between cancer cells and macrophages.

Tumor microenvironment (TME) exerts key roles in pancreatic ductal adenocarcinoma (PDAC) development. However, the factors regulating the cross-talk between PDAC cells and TME are largely unknown. In the present study, we identified a long noncoding RNA (lncRNA) KLHDC7B divergent transcript (KLHDC7B-DT), which was up-regulated in PDAC and correlated with poor survival of PDAC patients. Functional assays demonstrated that KLHDC7B-DT enhanced PDAC cell proliferation, migration, and invasion. Mechanistically, KLHDC7B-DT was found to directly bind IL-6 promoter, induce open chromatin structure at IL-6 promoter region, activate IL-6 transcription, and up-regulate IL-6 expression and secretion. The expression of KLHDC7B-DT was positively correlated with IL-6 in PDAC tissues. Via inducing IL-6 secretion, KLHDC7B-DT activated STAT3 signaling in PDAC cells in an autocrine manner. Furthermore, KLHDC7B-DT also activated STAT3 signaling in macrophages in a paracrine manner, which induced macrophage M2 polarization. KLHDC7B-DT overexpressed PDAC cells-primed macrophages promoted PDAC cell proliferation, migration, and invasion. Blocking IL-6/STAT3 signaling reversed the effects of KLHDC7B-DT on macrophage M2 polarization and PDAC cell proliferation, migration, and invasion. In conclusion, KLHDC7B-DT enhanced malignant behaviors of PDAC cells via IL-6-induced macrophage M2 polarization and IL-6-activated STAT3 signaling in PDAC cells. The cross-talk between PDAC cells and macrophages induced by KLHDC7B-DT represents potential therapeutic target for PDAC.

The Role of Forkhead Box Q1 Transcription Factor in Anticancer Effects of Withaferin A in Breast Cancer.

Elimination of both rapidly dividing epithelial mammary cancer cells as well as breast cancer stem-like cells (bCSC) is essential for maximizing antitumor response. Withaferin A (WA), a small molecule derived from a medicinal plant (Withania somnifera), is highly effective in reducing burden and/or incidence of breast cancer in vivo in various preclinical models. We have shown previously that suppression of breast cancer incidence by WA administration in a rat model is associated with a decrease in self-renewal of bCSC but the underlying mechanism is still elusive. This study investigated the role of forkhead box Q1 (FoxQ1) transcription factor in antitumor responses to WA. Exposure of MDA-MB-231 and SUM159 cells to WA resulted in downregulation of protein and mRNA levels of FoxQ1 as well as inhibition of its transcriptional activity. FoxQ1 overexpression in SUM159 and MCF-7 cells resulted in a marked protection against WA-mediated inhibition of bCSC as judged by flow cytometric analysis of CD49fhigh population and mammosphere assay. RNA-sequencing analysis revealed upregulation of many bCSC-associated genes by FoxQ1 overexpression in SUM159 cells, including IL8 whose expression was decreased by WA treatment in SUM159 and MCF-7 cells. FoxQ1 was recruited to the promoter of IL8 that was inhibited significantly by WA treatment. On the other hand, WA-mediated inhibition of cell proliferation or migration was not affected by FoxQ1 overexpression. The FoxQ1 overexpression partially attenuated WA-mediated G2-M phase cell cycle arrest in SUM159 cells only. These results indicate that FoxQ1 is a target of WA for inhibition of bCSC fraction. PREVENTION RELEVANCE: Withaferin A (WA) is highly effective in reducing burden and/or incidence of breast cancer in various preclinical models. However, the mechanism underlying breast cancer prevention by WA is not fully understood. This study shows a role for FoxQ1 in antitumor response to WA.

Effects of systemic inflammation on relapse in early breast cancer

Chronic inflammation has been a proposed mechanism of resistance to aromatase inhibitors in breast cancer. Stratifying by HER2 status, a matched case-control study from the Wellness After Breast Cancer-II cohort was performed to assess whether or not elevated serum inflammatory biomarkers (C-Reactive protein [CRP], interleukin-6 [IL-6], and serum amyloid A [SAA]) and/or the presence of a high-risk IL-6 promoter genotype were associated with recurrence of hormone receptor positive (HR+) early breast cancer. Estrogen levels were also measured and correlated with biomarkers and disease outcomes. CRP and SAA were significantly associated with an increased risk of recurrence in the HR+/HER2− group, but not the HR+/HER2+ group. Mean serum estrogen levels were non-significantly elevated in patients who relapsed vs. non-relapsed patients. Surprisingly, high-risk IL-6 promoter polymorphisms were strongly associated with HER2+ breast cancer relapse, which has potential therapeutic implications, as elevated intracellular IL-6 has been associated with trastuzumab resistance in pre-clinical models.

Interleukin-6 Promotes Cervical Cancer Development Through Janus Kinase 2/Signal Transducer and Activator of Transcription 6 Signaling Pathway

Interleukin (IL)-6 regulates several cellular processes such as proliferation, differentiation and immune regulation. The pathogenesis of cervical cancer is closely related to abnormal secretion and regulation of cytokines. IL-6 in the pathogenesis of cervical cancer was investigated in the present study. In our work, we collected cervical cancer tissues and adjacent normal tissues first and then established mouse model of cervical cancer for following assays. Immunohistochemistry and Western blot analysis were performed to detect IL-6, JAK3 and STAT6 and qRT-PCR determined VEGF, MMP-2, MMP-9 and others in adjacent tissues and cancer tissues. MTT was used to detect the capability of proliferation, invasion and migration. Chromatin immunoprecipitation was employed to verify the binding of STAT6 to IL-6. The effect of STAT6 inhibitors, AS1517499 on JAK3/STAT6 axis was also detected through in vivo experiments. Except IL-6, the related proteins were upregulated in cervical cancer tissues. IL-6 (25–100 ng/mL) accelerated the growth of Hela cells. IL-6 improved cell migratory and invasive ability when recombinant IL-6 promoted phosphory-lation and JAK3/STAT6. The activity of IL-6 in Hela was mediated by JAK3/STAT6 signaling pathway as AS1517499 inhibited IL-6-induced JAK3/STAT6 phosphorylation and STAT6 bound to the IL-6 promoter. STAT6 inhibitors significantly suppressed tumor growth and reduced p-STAT3 level. IL-6 contributes to cervical cancer through JAK3/STAT6 signaling which could be a cornerstone of subsequent anti-cervical cancer treatment.

Interleukin 9 serum level and single nucleotide polymorphism in patients with asthma.

Background:Asthma is a chronic inflammatory disease of airways which accounts for a huge economic, morbidity, and mortality burden. There are different cytokines that contribute to asthma pathophysiology. Learning about these cytokines leads to attaining novel anti-inflammatory treatments for asthma control.Objectives:The objective of this study is to investigate the association between interleukin-9 serum level and gene polymorphism with asthma susceptibility.Methods:This was a case-control study of 70 asthmatic patients and 77 healthy control adults aged 18-60. Asthma diagnosis and severity were based on physician diagnosis, pulmonary function test (PFT) and 2016 guild line of Global Initiative for Asthma (GINA). Interleukin 9(IL -9) serum level was measured using sandwich enzyme linked immunosorbent assay. IL9 promoter single nucleotide polymorphism (SNP) (rs2069882) was also assessed using Real-Time PCR System.Results:There was no significant association between IL-9 SNP polymorphism and asthma. IL-9 serum level was significantly associated with asthma susceptibility (p value= 0.016) and absolute eosinophil count (AEC) (P value=0.033) however, its correlation with atopic asthma type, asthma severity and Immunoglubin E serum level were not statistically significant.Conclusion:Although there was no association between IL-9 SNP and asthma, but IL-9 serum level was significantly correlated with asthma susceptibility and AEC. (www.actabiomedica.it)

Impact of IL-10 Promoter Polymorphisms and IL-10 Serum Levels on Advanced Laryngeal Squamous Cell Carcinoma and Survival Rate.

Prognosis of advanced stages of laryngeal squamous cell carcinoma (LSCC) remains poor. To clarify therapeutic targets and improve survival rate, identification of new specific and prognostic biomarkers of LSCC is required. The study aimed to evaluate the impact of IL-10:rs1800871, rs1800872, rs1800896 single nucleotide polymorphisms (SNPs), and IL-10 serum levels on LSCC development and determine associations of selected SNPs with patient survival rate. A total of 300 LSCC patients and 533 controls were included in the study. Genotyping was carried out using RT-PCR; IL-10 serum levels were analyzed by ELISA. Significant associations were identified between IL-10 rs1800871 variants and advanced stage of LSCC patient group in the codominant, recessive and additive models (OR=0.473, p=0.027; OR=0.510, p=0.040; and OR=0.733; p=0.037). Significant variants of IL-10 rs1800872 were determined in the codominant, recessive and additive models (OR=0.473, p=0.027; OR=0.510, p=0.040; and OR=0.733, p=0.037). The distribution of IL-10 SNPs genotypes did not impact LSCC patient survival rate (respectively, p=0.952; p=0.952; p=0.991). IL-10:rs1800871 and rs1800872 SNPs are associated with advanced stage of LSCC. The genotypic distribution of IL-10 SNPs does not influence the survival rate of LSCC patients.

Tumor exosome promotes Th17 cell differentiation by transmitting the lncRNA CRNDE-h in colorectal cancer

The T helper 17 (Th17) cells in tumor microenvironment play an important role in colorectal cancer (CRC) progression. This study investigated the mechanism of Th17 cell differentiation in CRC with a focus on the role of tumor exosome-transmitted long noncoding RNA (lncRNA). Exosomes were isolated from the CRC cells and serum of CRC patients. The role and mechanism of the lncRNA CRNDE-h transmitted by CRC exosomes in Th17 cell differentiation were assessed by using various molecular biological methods. The serum exosomal CRNDE-h level was positively correlated with the proportion of Th17 cells in the tumor-infiltrating T cells in CRC patients. CRC exosomes contained abundant CRNDE-h and transmitted them to CD4+ T cells to increase the Th17 cell proportion, RORγt expression, and IL-17 promoter activity. The underlying mechanism is that, CRNDE-h bound to the PPXY motif of RORγt and impeded the ubiquitination and degradation of RORγt by inhibiting its binding with the E3 ubiquitin ligase Itch. The in vivo experiments confirmed that the targeted silence of CRNDE-h in CD4+ T cells attenuated the CRC tumor growth in mice. The present findings demonstrated that the tumor exosome transmitted CRNDE-h promoted Th17 cell differentiation by inhibiting the Itch-mediated ubiquitination and degradation of RORγt in CRC, expanding our understanding of Th17 cell differentiation in CRC.

The histone demethylase KDM6B fine-tunes the host response to Streptococcus pneumoniae.

Streptococcus pneumoniae is a natural colonizer of the human respiratory tract and an opportunistic pathogen. Although epithelial cells are among the first to encounter pneumococci, the cellular processes and contribution of epithelial cells to the host response are poorly understood. Here, we show that a S. pneumoniae serotype 6B ST90 strain, which does not cause disease in a murine infection model, induces a unique NF-κB signature response distinct from an invasive-disease-causing isolate of serotype 4 (TIGR4). This signature is characterized by activation of p65 and requires a histone demethylase KDM6B. We show, molecularly, that the interaction of the 6B strain with epithelial cells leads to chromatin remodelling within the IL-11 promoter in a KDM6B-dependent manner, where KDM6B specifically demethylates histone H3 lysine 27 dimethyl. Remodelling of the IL-11 locus facilitates p65 access to three NF-κB sites that are otherwise inaccessible when stimulated by IL-1β or TIGR4. Finally, we demonstrate through chemical inhibition of KDM6B with GSK-J4 inhibitor and through exogenous addition of IL-11 that the host responses to the 6B ST90 and TIGR4 strains can be interchanged both in vitro and in a murine model of infection in vivo. Our studies therefore reveal how a chromatin modifier governs cellular responses during infection.

Interleukin-13 Promoter Genotypes and Taiwanese Breast Cancer Susceptibility.

The current study aimed at evaluating the contribution of IL-13 promoter rs1881457 and rs1800925 genotypes to the risk of breast cancer in Taiwan. A total of 1,232 breast cancer cases and 1,232 age-matched controls were genotyped by typical polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. As for IL-13 rs1881457, the rates of AA, AC and CC genotypes were 54.8, 37.9 and 7.3% among the cases, and 53.8, 38.7 and 7.5% among the healthy controls, respectively; there were no statistically significant differences between the two groups (p for trend=0.8889). Also, regarding IL-13 rs1800925, there were no statistically significant differences between the two groups either (p for trend=0.6803). Furthermore, the allelic frequencies for IL-13 rs1881457 and rs1800925 were not differentially distributed between the case and control groups (p=0.6515 and 0.8753, respectively). The rs1881457 and rs1800925 IL-13 promoter polymorphisms may not serve as breast cancer susceptibility determinants for Taiwanese.

The Role of Epigenetics in the Chronic Sinusitis with Nasal Polyp.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common and heterogeneous inflammatory disease. The underlying epigenetic mechanisms and treatment of CRSwNP are partially understood. Of the different epigenetic changes in CRSwNP, histone deacetylases (HDACs), methylation of DNA, and the levels of miRNA are widely studied. Here, we review the human studies of epigenetic mechanisms in CRSwNP. The promoters of COL18A1, PTGES, PLAT, and TSLP genes are hypermethylated in CRSwNP compared with those of controls, while the promoters of PGDS, ALOX5AP, LTB4R, IL-8, and FZD5 genes are hypomethylated in CRSwNP. Promoter hypermethylation suppresses the gene expression, while promoter hypomethylation increases the gene expression. Studies have shown the elevation in the levels of HDAC2, HDAC4, and H3K4me3 in CRSwNP. In CRSwNP patients, there is also an upregulation of certain miRNAs including miR-125b, miR-155, miR-19a, miR-142-3p, and miR-21 and downregulation of miR-4492. Epigenetics takes part in the immunology of CRSwNP and may give rise to endotypes of CRSwNP. Both HDAC2 and the miRNA including miR-18a, miR-124a, and miR-142-3p may take function in the regulation of glucocorticoid resistance. HDAC inhibitors and KDM2B have shown effectiveness in decreasing nasal polyp, and DNA methyltransferase (DNMT) or HDAC inhibitors may have a potential efficacy for the treatment of CRSwNP. Recent advances in the epigenetics of CRSwNP have led to the identification of several potential therapeutic targets for this disease. The use of epigenetics may provide novel and effective biomarkers and therapies for the treatment of nasal polyp.

THE ROLE OF INTERLEUKIN-4 GENE PROMOTER POLYMORPHISMS IN GRAVES’ DISEASE

Objective: This study was conducted to prove the role of interleukin-4 gene promoter polymorphisms in Graves’ disease patients in M Djamil General Hospital Padang, Indonesia.
 Methods: This study was conducted from August 2015 until December 2015 in the Internal Medicine Department in Dr. M. Djamil Hospital, Padang, West Sumatera, Indonesia. This study involved 15 patients with Graves’ disease and 15 normal subjects. We examined that IL-4 promoter gene polymorphism was examined with PCR.
 Results: Sequencing examination on IL-4 gene promoter resulted in 2 Single Nucleotide Polymorphism (SNP) motifs, which is rs2243250 and rs2070847. IL-4 SNP gene promoter polymorphisms rs2243250 and rs2070847 were found in both patient and control groups. TT is homozygous SNP polymorphisms. CT is heterozygous SNP polymorphisms. CC is wild type or no mutation SNP polymorphisms. Based on statistical tests, no difference in rs2243250 and rs2070847 SNP polymorphisms was found between patient and control group (p > 0.05).
 Conclusion: This study observed no difference in interleukin-4 gene promoter polymorphism between Graves’ disease patients and control group.

CLL-Derived Exosomes Educate Endothelial Cells to Become CLL-Supportive Cells

Background: CLL is characterized by a gradual accumulation of mature appearing long-lived lymphocytes. Several pro-survival pathways that protect CLL cells from apoptosis are activated in these cells. For example, IL-6 dependent phosphorylation of the signal transducer and activator of transcription 3 (STAT3) provides CLL cells with a survival and a proliferative advantages. What is the source of IL-6 is currently unknown. Within lymphoid organs CLL cells engage in complex molecular interactions. In these sites, CLL cells are not simply the seeds that grow on the supportive soil of the microenvironment but play an active role in shaping its surrounding. Secreted by all types of cells, exosomes are nano-scaled particles that travel in blood and function as stable intercellular transport vehicles that deliver their cargo to cells that engulf them. For example, CLL-derived exosomes (herein CLL-exosomes) are taken up by mesenchymal stromal cells, transforming them to cancer associated fibroblasts. Given the appropriate stimulation, endothelial cells produce IL-6. Therefore, we hypothesized that CLL-exosomes actively recruit endothelial cells to become IL-6-secreting cells.Methods: CLL cells from 37 patients were included in this study. CLL-exosomes were isolated by ultracentrifugation. Electron microscopy, NanoSight tracking analysis, flow cytometry and Western immunoblotting were used to characterize CLL exosomes. Exosomal uptake by HUVECs was assessed by flow cytometry and fluorescent microscopy. The phosphor-protein profiling of exposed HUVECs was analyzed by mass spectrometry. RT-PCR and Western immunoblotting were used to determine the expression profile of HUVEC-exposed cells. HUVECs were transfected with β-catenin containing plasmid using DNA transfection reagent. Cytokine levels were determined by ELISA and CHIP assay was used to identify activated transcription factors .Results: First, we isolated CLL-exosomes from 37 treatment naïve patients. For that purpose we grew CLL cells and collected the secreted exosomes after 72 hours by ultracentrifugation. By NanoSight tracking system we identified large amount of exosomes and verified the presence of the typical cap shaped vesicles by electron microscopy. Western immunoblotting confirmed the presence of CD63 and CD81 exosomal markers and by flow we detected CD19/CD5 on these particles. Next, we exposed HUVECs to an increasing amount of CLL-exosomes and verified by two distinct methods that these particles are up taken by HUVECs in a dose- and time- dependent manner. By mass spectrometry we found 53 phosphorproteins that were at least 2 folds upregulated and none that were downregulated in HUVEC-exposed cells. Pathway analysis unraveled the central position of β-catenin. Immunoprecipitation studies verified that levels of phosphor-β-catenin are upregulated while levels of total β-catenin remained unchanged, suggesting that CLL-exosomes induced phosphorylation rather than the generation of newly formed β-catenin and leaving us wondering whether upregulation of phosphor β-catenin is somehow beneficial to their parental neoplastic cells. Because the IL-6 promoter binds 3 transcription factors that are activated by β-catenin we assumed that by activating the β-catenin pathway, endothelial cells become "micro factories" for the production of humoral IL-6. To verify the role of β-catenin in promoting production of IL-6 molecules in endothelial cells we transfected HUVECs with β-catenin containing plasmid. By Western immunoblotting we verified that the protein levels of β-catenin were upregulated. Then, by ChIP assay we found that 3 different transcription factors, namely LEF/TCF, CEBP and NFkB increased their binding to the IL-6 promoter region by 1.5 to 12 folds in HUVECs that were transfected with β-catenin ORF. Finally we show that intracellular STAT3 of CLL cells that were grown on this IL-6-rich medium are phosphorylated on tyrosine residues and that the rate of CLL cells in active apoptosis was markedly decreased. Conclusions: CLL cells shape their own fate. They do so by sending exosomes that activate the β-catenin axes. In this way CLL cells reprogram endothelial cells to become IL-6 producing cells and IL-6 contributes to CLL cells' survival. Disclosures No relevant conflicts of interest to declare.

Zinc deficiency leads to reduced interleukin-2 production by active gene silencing due to enhanced CREMα expression in T cells

The micronutrient zinc is essential for proper immune function. Consequently, zinc deficiency leads to impaired immune function, as seen in decreased secretion of interleukin (IL)-2 by T cells. Although this association has been known since the late 1980s, the underlying molecular mechanisms are still unknown. Zinc deficiency and reduced IL-2 levels are especially found in the elderly, which in turn are prone to chronic diseases. Here, we describe a new molecular link between zinc deficiency and reduced IL-2 expression in T cells. The effects of zinc deficiency were first investigated invitro in the human T cell lines Jurkat and Hut-78 and complemented by invivo data from zinc-supplemented pigs. A short- and long-term model for zinc deficiency was established. Zinc levels were detected by flow cytometry and expression profiles were investigated on the mRNA and protein level. The expression of the transcription factor cAMP-responsive-element modulator α (CREMα) is increased during zinc deficiency invitro, due to increased protein phosphatase 2A (PP2A) activity, resulting in decreased IL-2 production. Additionally, zinc supplementation invivo reduced CREMα levels causing increased IL-2 expression. On epigenetic levels increased CREMα binding to the IL-2 promoter is mediated by histone deacetylase 1 (HDAC1). The HDAC1 activity is inhibited by zinc. Moreover, deacetylation of the activating histone mark H3K9 was increased under zinc deficiency, resulting in reduced IL-2 expression. With the transcription factor CREMα a molecular link was uncovered, connecting zinc deficiency with reduced IL-2 production due to enhanced PP2A and HDAC1 activity.

Short Communication: Genetic Variation in Human IL10 Proximal Promoter and Susceptibility to HIV-1 Infection in Mali, West Africa.

It is now recognized that to fully understand the role of host genetic variation on susceptibility to HIV-1 infection, investigations must be extended to African populations. We sought to determine if genetic variation in IL10 are associated with HIV-1 infection in a West African cohort in Mali. HIV-infected and -uninfected individuals were genotyped for three common single nucleotide polymorphisms (SNPs) located at positions -592 (C/A), -819 (C/T), and -1082 (G/A) of the IL10 promoter. We found that the ATA haplotype, which has been previously associated with low IL-10 expression, was the most represented in the cohort. Although we observed a trend toward an increased frequency of ATA/ATA carriage in HIV-infected compared with -uninfected individuals, the difference was not statistically significant. Similarly, individual IL10 SNPs were not significantly enriched in the HIV-infected group, suggesting that IL10 genetic variants are not associated with HIV-1 in this West African cohort from Mali.

USP38 Couples Histone Ubiquitination and Methylation via KDM5B to Resolve Inflammation.

Chromatin modifications, such as histone acetylation, ubiquitination, and methylation, play fundamental roles in maintaining chromatin architecture and regulating gene transcription. Although their crosstalk in chromatin remodeling has been gradually uncovered, the functional relationship between histone ubiquitination and methylation in regulating immunity and inflammation remains unclear. Here, it is reported that USP38 is a novel histone deubiquitinase that works together with the histone H3K4 modifier KDM5B to orchestrate inflammatory responses. USP38 specifically removes the monoubiquitin on H2B at lysine 120, which functions as a prerequisite for the subsequent recruitment of demethylase KDM5B to the promoters of proinflammatory cytokines Il6 and Il23a during LPS stimulation. KDM5B in turn inhibits the binding of NF‐κB transcription factors to the Il6 and Il23a promoters by reducing H3K4 trimethylation. Furthermore, USP38 can bind to KDM5B and prevent it from proteasomal degradation, which further enhances the function of KDM5B in the regulation of inflammation‐related genes. Loss of Usp38 in mice markedly enhances susceptibility to endotoxin shock and acute colitis, and these mice display a more severe inflammatory phenotype compared to wild‐type mice. The studies identify USP38‐KDM5B as a distinct chromatin modification complex that restrains inflammatory responses through manipulating the crosstalk of histone ubiquitination and methylation.

Hepatic NFAT signaling regulates the expression of inflammatory cytokines in cholestasis

The nuclear factor of activated T-cells (NFAT) plays an important role in immune responses by regulating the expression of inflammatory genes. However, it is not known whether NFAT plays any role in the bile acid (BA)-induced hepatic inflammatory response. Thus, we aimed to examine the functional role of NFATc3 in cholestatic liver injury in mice and humans. Gene and protein expression and cellular localization were assessed in primary hepatocyte cultures (mouse and human) and cholestatic liver tissues (murine models and patients with primary biliary cholangitis [PBC] or primary sclerosing cholangitis [PSC]) by quantitative PCR, western blot and immunohistochemistry. Specific NFAT inhibitors were used invivo and invitro. Gene reporter assays and ChIP-PCR were used to determine promoter activity. NFAT isoforms c1 and c3 were expressed in human and mouse hepatocytes. When treated with cholestatic levels of BAs, nuclear translocation of NFATc3 was increased in both human and mouse hepatocytes and was associated with elevated mRNA levels of IL-8, CXCL2, and CXCL10 in these cells. Blocking NFAT activation with pathway-specific inhibitors or knocking down Nfatc3 expression significantly decreased BA-driven induction of these cytokines in mouse hepatocytes. Nuclear expression of NFATc3/Nfatc3 protein was increased in cholestatic livers, both in mouse models (bile duct ligation or Abcb4-/- mice) and in patients with PBC and PSC in association with elevated tissue levels of Cxcl2 (mice) or IL-8 (humans). Gene reporter assays and ChIP-PCR demonstrated that the NFAT response element in the IL-8 promoter played a key role in BA-induced human IL-8 expression. Finally, blocking NFAT activation invivo in Abcb4-/- mice reduced cholestatic liver injury. NFAT plays an important role in BA-stimulated hepatic cytokine expression in cholestasis. Blocking hepatic NFAT activation may reduce cholestatic liver injury in humans. Bile acid induces liver injury by stimulating the expression of inflammatory genes in hepatocytes through activation of the transcription factor NFAT. Blocking this activation invitro (in hepatocyte cultures) and invivo (in cholestatic mice) decreased the expression of inflammatory genes and reduced liver injury.

Lysyl oxidase directly contributes to extracellular matrix production and fibrosis in systemic sclerosis.

Pulmonary fibrosis is one of the important causes of morbidity and mortality in fibroproliferative disorders such as systemic sclerosis (SSc) and idiopathic pulmonary fibrosis (IPF). Lysyl oxidase (LOX) is a copper-dependent amine oxidase whose primary function is the covalent crosslinking of collagens in the extracellular matrix (ECM). We investigated the role of LOX in the pathophysiology of SSc. LOX mRNA and protein levels were increased in lung fibroblasts of SSc patients compared with healthy controls and IPF patients. In vivo, bleomycin induced LOX mRNA expression in lung tissues, and LOX activity increased in the circulation of mice with pulmonary fibrosis, suggesting that circulating LOX parallels levels in lung tissues. Circulating levels of LOX were reduced upon amelioration of fibrosis with an antifibrotic peptide. LOX induced ECM production at the transcriptional level in lung fibroblasts, human lungs, and human skin maintained in organ culture. In vivo, LOX synergistically exacerbated fibrosis in bleomycin-treated mice. Further, LOX increased the production of interleukin (IL)-6, and the increase was mediated by LOX-induced c-Fos expression, the nuclear localization of c-Fos, and its engagement with the IL-6 promoter region. Our findings demonstrate that LOX expression and activity correlate with fibrosis in vitro, ex vivo, and in vivo. LOX induced ECM production via upregulation of IL-6 and nuclear localization of c-Fos. Thus, LOX has a direct pathogenic role in SSc-associated fibrosis that is independent of its crosslinking function. Our findings also suggest that measuring circulating LOX levels and activity can be used for monitoring response to antifibrotic therapy.

Host Genetic Variants Potentially Associated With SARS-CoV-2: A Multi-Population Analysis.

BackgroundClinical outcomes of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) showed enormous inter-individual and inter-population differences, possibly due to host genetics differences. Earlier studies identified single nucleotide polymorphisms (SNPs) associated with SARS-CoV-1 in Eastern Asian (EAS) populations. In this report, we aimed at exploring the frequency of a set of genetic polymorphisms that could affect SARS-CoV-2 susceptibility or severity, including those that were previously associated with SARS-CoV-1.MethodsWe extracted the list of SNPs that could potentially modulate SARS-CoV-2 from the genome wide association studies (GWAS) on SARS-CoV-1 and other viruses. We also collected the expression data of these SNPs from the expression quantitative trait loci (eQTLs) databases. Sequences from Qatar Genome Programme (QGP, n = 6,054) and 1000Genome project were used to calculate and compare allelic frequencies (AF).ResultsA total of 74 SNPs, located in 10 genes: ICAM3, IFN-γ, CCL2, CCL5, AHSG, MBL, Furin, TMPRSS2, IL4, and CD209 promoter, were identified. Analysis of Qatari genomes revealed significantly lower AF of risk variants linked to SARS-CoV-1 severity (CCL2, MBL, CCL5, AHSG, and IL4) compared to that of 1000Genome and/or the EAS population (up to 25-fold change). Conversely, SNPs in TMPRSS2, IFN-γ, ICAM3, and Furin were more common among Qataris (average 2-fold change). Inter-population analysis showed that the distribution of risk alleles among Europeans differs substantially from Africans and EASs. Remarkably, Africans seem to carry extremely lower frequencies of SARS-CoV-1 susceptibility alleles, reaching to 32-fold decrease compared to other populations.ConclusionMultiple genetic variants, which could potentially modulate SARS-CoV-2 infection, are significantly variable between populations, with the lowest frequency observed among Africans. Our results highlight the importance of exploring population genetics to understand and predict COVID-19 outcomes. Indeed, further studies are needed to validate these findings as well as to identify new genetic determinants linked to SARS-CoV-2.

Adenovirus 7 Induces Interlukin-6 Expression in Human Airway Epithelial Cells via p38/NF-κB Signaling Pathway.

Human Adenovirus (AdV) infection is very common and usually has a significant impact on children. AdV-induced inflammation is believed to be one of the main causes of severe symptoms. However, an inflammatory response profile in the airway in AdV-infected children is still lacking, and the mechanism underlying AdV-induced inflammation in the airway is also poorly understood. In the current study, we determined the expression of a panel of inflammation cytokines in the airway samples from AdV 7 infected children and further investigated the molecular mechanism underlying AdV 7-induced cytokine expression. Our results showed that eight out of 13 tested inflammatory cytokines were significantly increased in nasal washes of AdV 7-infected children comparing to healthy control, with IL-6 showing the highest enhancement. AdV 7 infection of bronchial epithelial cell line and primary airway epithelial cells confirmed that AdV 7 increased IL-6 mRNA and protein expression in an infection dose-dependent manner. Promoter analysis revealed that AdV 7 infection transactivated IL-6 promoter and a NF-κB binding site in IL-6 promoter was involved in the transactivation. Further analysis showed that upon AdV 7 infection, NF-κB p65 was phosphorylated and translocated into nucleus and bound onto IL-6 promoter. Signaling pathway analysis revealed that p38/NF-κB pathway was involved in AdV 7 infection induced IL-6 elevation. Taken together, our study shows that AdV 7 infection triggers the expression of a range of inflammatory cytokines including IL-6 in the airway of infected children, and AdV 7 enhances IL-6 expression by transactivating IL-6 promoter via p38/NF-κB signaling pathway. Findings of our current study have provided more information toward a better understanding of AdV-induced airway inflammation, which might also benefit the development of intervention strategies.