IL-10 Knockout Research Articles

Endogenous Interleukin 18 Suppresses Liver Regeneration After Hepatectomy in Mice.

The comprehensive role of interleukin (IL) 18 during liver regeneration is barely studied. Our aim is to evaluate the role of IL18 in liver regeneration after partial hepatectomy (PH) in mice. The expression profile of IL18 in the liver and the gut after 70% PH was measured. Liver samples after 70% and 85% PH from IL18 knockout (IL18-/- ) mice and wild type (WT) mice were collected for comparison of liver regeneration. The effect of recombinant IL18 on liver regeneration was tested in IL18-/- mice, and the utility of IL18 binding protein (BP) was also evaluated following 70% PH in WT mice. Expression levels of IL18 in the liver and the gut elevated after 70% PH. The liver weight/body weight ratios (LBWRs) after PH were significantly higher in IL18-/- mice than those in WT mice. Recombinant IL18 injection significantly decreased LBWR at 7days after 70% PH in IL18-/- mice. The expression of cyclin D1, EdU labeling index, and Ki-67 proliferation index were much higher in IL18-/- mice than those in WT mice after 70% PH. The expression level of glypican 3 (GPC3) in WT mice significantly elevated during liver regeneration. In contrast, the expression level of GPC3 in IL18-/- mice remained roughly unchanged during liver regeneration. IL18BP injection significantly increased the LBWR at 7days after 70% PH in WT mice. In conclusion, endogenous IL18 inhibited liver regeneration after PH in mice, possibly through up-regulating GPC3. IL18BP may be an effective agent to promote liver regeneration after PH.

Interleukin-6 Derived from the Central Nervous System May Influence the Pathogenesis of Experimental Autoimmune Encephalomyelitis in a Cell-Dependent Manner.

Background: Interleukin-6 (IL-6) is a pleiotropic and multifunctional cytokine that plays a critical role in induction of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS). Although EAE has always been considered a peripherally elicited disease, Il6 expression exclusively within central nervous system is sufficient to induce EAE development. Neurons, astrocytes, and microglia can secrete and respond to IL-6. Methods: To dissect the relevance of each cell source for establishing EAE, we generated and immunized conditional Il6 knockout mice for each of these cell types with myelin oligodendrocyte glycoprotein 35-55 (MOG35-55) peptide dissolved in complete Freund’s adjuvant (CFA) and supplemented with Mycobacterium tuberculosis. Results and conclusions: The combined results reveal a minor role for Il6 expression in both astrocytes and microglia for symptomatology and neuropathology of EAE, whereas neuronal Il6 expression was not relevant for the variables analyzed.

Skin Cutibacterium acnes Mediates Fermentation to Suppress the Calcium Phosphate-Induced Itching: A Butyric Acid Derivative with Potential for Uremic Pruritus.

Pruritus and inflammation associated with accumulation of calcium phosphate (CaP) under the skin are common problems among dialysis patients with chronic kidney disease (CKD). The role of skin commensal microbiota in the CaP-induced uremic pruritus remains uncharacterized. Skin Cutibacterium acnes (C. acnes) can solubilize CaP by the production of short-chain fatty acids (SCFAs), such as butyric acid, through glucose fermentation. Like butyric acid, the N-[2-(2-Butyrylamino-ethoxy)-ethyl]-butyramide (BA-NH-NH-BA), a butyric acid derivative, remarkably induced acetylation of histone H3 lysine 9 (AcH3K9) in keratinocytes. Topical application of fermenting C. acnes, butyric acid or BA-NH-NH-BA onto mouse skin effectively ameliorated CaP-induced skin itching, interleukin (IL)-6 up-regulation in keratinocytes, and extracellular signal-regulated kinase (ERK) 1/2 activation in dorsal root ganglia (DRG). Activation of ERK 1/2 by CaP was markedly reduced in IL-6 knockout mice. Genus Cutibacterium was detected in relatively low abundance in itchy skin of patients with CKD. Our results identify a role for the skin fermenting C. acnes in ameliorating CaP-induced activation of IL-6/p-ERK signaling and resulting skin inflammation. Furthermore, we provide evidence for the potential therapeutic efficacy of BA-NH-NH-BA as a postbiotic for the treatment of uremic pruritus.

OP31 Meta–omics reveals microbiome-driven proteolysis as a contributing factor to the severity of ulcerative colitis disease activity

Abstract Background Ulcerative colitis (UC) is characterised by an aberrant immune response directed towards the gut microbiota. It remains poorly understood which mechanisms govern pathogenic roles of the microbiome in UC. Methods A prospective cohort of 40 UC patients were phenotyped with clinical (partial Mayo), biochemical (faecal calprotectin), endoscopic (Mayo endoscopic sub-score and ulcerative colitis Endoscopic Index of Severity) and histologic (Geboes) disease activity indices. Individual patient-matched faecal samples collected within 24 h prior to the lower endoscopy underwent 16S, shotgut metagenomic, metabolomic, metaproteomic, and metapeptidomic sequencing in addition to proteomic sequencing of paired serum samples. Sequencing datasets were integrated and analysed for microbial determinants of UC disease severity. Confirmatory in-vivo and in-vitro experiments were performed in Caco-2 epithelial monolayers and IL10 knockout mice. Results All meta-omics displayed large-scale shifts related to disease severity, with the metabolome and metaproteome best predicting disease severity and the metapeptidome demonstrating an increase of peptide fragments in UC patients with high severity. Broad-scale analyses and taxonomic inferences identified Bacteroides proteases as a distinguishing feature of disease severity, with the Bacteroides association being driven by changes in protease protein expression. Using a Caco-2 model we confirmed that epithelial disruption by Bacteroides vulgatus was prevented by protease inhibition, without influencing growth rates. Guided by the metagenome and metaproteome we transplanted a high-severity UC faecal sample with an increased abundance of proteases related to Bacteroides vulgatus into an IL10−/− gnotobiotic mouse model, and observed that colitis induced by transplant of faeces was attenuated by oral administration of protease inhibitors. Conclusion Through an integrated multi-omics data analysis we demonstrate that certain members of the microbiome, such as Bacteroides vulgatus, may contribute to exacerbating disease activity in UC through protease activity. In-vivo and in-vitro experiments provide evidence that bacterial protease inhibition may be a novel therapeutic approach in UC.

Novel Histone Deacetylase 6 Inhibitor CKD-506 Inhibits NF-κB Signaling in Intestinal Epithelial Cells and Macrophages and Ameliorates Acute and Chronic Murine Colitis.

Selective blocking of HDAC6 has become a promising strategy in treating inflammatory bowel disease. CKD-506 is a novel isoform-selective inhibitor of histone deacetylase 6. The present study was performed to evaluate the effect of CKD-506 on the NF-κB signaling pathway in intestinal epithelial cells (IECs) and macrophages and on murine models of acute and chronic colitis. RAW264RAW264.7 murine macrophages and COLO 205 human IECs were pretreated with CKD-506 and then stimulated with lipopolysaccharides (LPS). Cytokine expression of TNF-α, interleukin (IL)-6, IL-8, and IL-10 was measured by ELISA. The effect of CKD-506 on NF-κB signaling was evaluated by Western blotting of IκBα phosphorylation/degradation and electrophoretic mobility shift assay. In vivo studies were performed using a dextran sulfate sodium (DSS)-induced acute colitis model, a chronic colitis model in IL-10 knockout mice, and an adoptive transfer model. Colitis was quantified by the disease activity index, colon length, and histopathologic evaluation. CKD-506 suppressed the expression of pro-inflammatory cytokines such as IL-6, IL-8, and TNF-α in IECs and macrophages. CKD-506 strongly inhibited IκBα phosphorylation/degradation and the DNA-binding activity of NF-κB. Oral administration of CKD-506 attenuated DSS-induced acute colitis and chronic colitis in IL-10-/- and adoptive transfer models. CKD-506 ameliorated weight loss, disease activity, and histopathologic score in colitis mice and downregulated IκBα phosphorylation and pro-inflammatory cytokine production significantly. CKD-506 blocked NF-κB signaling in IECs and macrophages and ameliorated experimental acute and chronic murine colitis models, which suggests that CKD-506 is a promising candidate for inflammatory bowel disease treatment as a small molecular medicine.

Organic dust-induced lung injury and repair: Bi-directional regulation by TNFα and IL-10

Exposure to organic dust increases chronic airway inflammatory disorders. Effective treatment strategies are lacking. It has been reported that hog barn dust extracts (HDE) induce TNFα through protein kinase C (PKC) activation and that lung inflammation is enhanced in scavenger receptor A (SRA/CD204) knockout (KO) mice following HDE. Because interleukin (IL)-10 production can limit excessive inflammation, it was hypothesized here that HDE-induced IL-10 would require CD204 to effect inflammatory responses. C57BL/6 wild-type (WT), SRA KO, and IL-10 KO mice were intranasally challenged daily for 8 days with HDE and subsequently rested for 3 days with/without recombinant IL-10 (rIL-10) treatment. Primary peritoneal macrophages (PM) and murine alveolar macrophages (MH-S cells) were treated in vitro with HDE, SRA ligand (fucoidan), rIL-10, and/or PKC isoform inhibitors. HDE induced in vivo lung IL-10 in WT, but not SRA KO mice, and similar trends were demonstrated in isolated PM from same treated mice. Lung lymphocyte aggregates and neutrophils were elevated in in vivo HDE-treated SRA and IL-10 KO mice after a 3-d recovery, and treatment during recovery with rIL-10 abrogated these responses. In vitro rIL-10 treatment reduced HDE-stimulated TNFα release in MH-S and WT PM. In SRA KO macrophages, there was reduced IL-10 and PKC zeta (ζ) activity and increased TNFα following in vitro HDE stimulation. Similarly, blocking SRA (24 hr fucoidan pre-treatment) resulted in enhanced HDE-stimulated macrophage TNFα and decreased IL-10 and PKCζ activation. PKCζ inhibitors blocked HDE-stimulated IL-10, but not TNFα. Collectively, HDE stimulates IL-10 by an SRA- and PKCζ-dependent mechanism to regulate TNFα. Enhancing resolution of dust-mediated lung inflammation through targeting IL-10 and/or SRA may represent new approaches to therapeutic interventions.

Antioxidant and Anti-Inflammatory Effects of Anacardium occidentale L. and Anacardium microcarpum D. Extracts on the Liver of IL-10 Knockout Mice.

Background The Anacardium occidentale L. (cashew) and Anacardium microcarpum D. (cajuí) are plants commonly found in Brazil. They present phytochemical compounds with antioxidant and anti-inflammatory action. Therefore, the objective of this study was to analyze the antioxidant and anti-inflammatory activities of ethanolic extracts from leaves of A. occidentale and A. microcarpum and its effect on the hepatic tissue in experimental knockout models after they received Paracetamol®. Methods Ethanol extracts from A. occidentale and A. microcarpum leaves were prepared. Total phenolics were determined by Folin–Ciocalteau reagent, and flavonoids are based on the complexation reaction with the aluminum metal, forming a colored complex. Fingerprint HPLC was performed to detect phenolic compounds. Knockout IL-10 mice randomly divided into six groups were used and received the following treatments: G1, only water; G2, A. occidentale extract; G3, A. microcarpum extract; G4, Paracetamol®; G5, Paracetamol® + A. occidentale extract (400 mg/kg); G6, Paracetamol® + A. microcarpum extract (400 mg/kg). Biochemical parameters of the blood and differential count of leukocytes were done. Oxidative markers and histopathological analyses were performed on their liver tissue. Results Phenolic compounds and total flavonoids were detected in both two extracts analyzed. The HPLC fingerprint detected phenolic acid, gallic acid, and catechin flavonoid in the two extracts. Histopathological analyses of the hepatic tissue permitted evaluation of nuclear increase, sinusoid congestion, and inflammatory infiltrate. A. microcarpum presented more antioxidant activity increasing antioxidant enzyme levels and reducing TBARS and carbonyl protein when compared to the other treatments after exposure to Paracetamol®. Histopathological analyses showed a decrease in the inflammatory infiltrate after treatment with extracts. Conclusion Our findings indicate that both extracts, especially A. microcarpum, can reduce hepatic damage in knockout mice exposed to paracetamol, indicating the curative power of these extracts reducing lipid peroxidation and in the morphofunctional damage to the liver parenchyma.

188: Absence of IL-6 does not decrease pulmonary inflammation in two models of bronchopulmonary dysplasia (BPD)

BPD is the result of chronic pulmonary inflammation and abnormal alveolar remodeling. IL-6 is an inflammatory mediator which has been implicated in this process. Two models which produce BPD in mice have been previously reported. We sought to determine if perinatal IL-6 absence in these models of BPD attenuated pulmonary inflammation. IL-6 knockout (-/-) mice were compared wild-type C57BI6J mice (+/+) in order to determine if this exposure improved pulmonary inflammation. Day 14 Antepartum lipopolysaccharide (LPS) with and without postpartum hyperoxia were the two models of BPD. Litters were homogenized at birth and then randomly assigned by model type. On day 14 of life pups were sacrificed, and one third of them were randomly selected for assessment of inflammation. The primary outcome was pulmonary inflammation measured by inflammasome caspase-1 fluorometric activity at 14 days of life. Relative fluorescence units (RFU) were controlled by total protein concentration of each sample. Unpaired t-tests were utilized to determine differences between mice type for each model of BPD; a p-value < 0.05 was considered statistically significant. 23 pups were randomly selected for molecular inflammation analysis. In the LPS only model, 8 pups were analyzed. In the LPS and hyperoxia model, 15 pups were analyzed. There was no significant decrease in pulmonary inflammation between -/- and +/+ in the LPS only group (1213 vs 920 RFU/total protein, p=0.38). Additionally, there was no difference in pulmonary inflammation between the -/- and +/+ mice in the LPS and hyperoxia group (1650 vs 1559 RFU/total protein, p=0.76). Genetic IL-6 absence did not decrease pulmonary inflammation in two mouse models of BPD. Future studies should examine if a more physiologic imperfect IL-6 blockade will decrease pulmonary inflammation, due to IL-6’s roles in both the resolution of innate immunity and the development of acquired immunity.

1174: IL-6 Knockout decreases severity of lung injury in an experimental model of bronchopulmonary dysplasia (BPD)

1174: IL-6 Knockout decreases severity of lung injury in an experimental model of bronchopulmonary dysplasia (BPD)

Interleukin-10 Deficiency Alters Endothelial Progenitor Cell-Derived Exosome Reparative Effect on Myocardial Repair via Integrin-Linked Kinase Enrichment.

Rationale: Systemic inflammation compromises the reparative properties of endothelial progenitor cell (EPC) and their exosomes on myocardial repair, although the underlying mechanism of loss of function of exosomes from inflamed EPCs is still obscure. Objective: To determine the mechanisms of IL-10 (interleukin-10) deficient-EPC-derived exosome dysfunction in myocardial repair and to investigate if modification of specific exosome cargo can rescue reparative activity. Methods and Results: Using IL-10 knockout mice mimicking systemic inflammation condition, we compared therapeutic effect and protein cargo of exosomes isolated from wild-type EPC and IL-10 knockout EPC. In a mouse model of myocardial infarction (MI), wild-type EPC-derived exosome treatment significantly improved left ventricle cardiac function, inhibited cell apoptosis, reduced MI scar size, and promoted post-MI neovascularization, whereas IL-10 knockout EPC-derived exosome treatment showed diminished and opposite effects. Mass spectrometry analysis revealed wild-type EPC-derived exosome and IL-10 knockout EPC-derived exosome contain different protein expression pattern. Among differentially expressed proteins, ILK (integrin-linked kinase) was highly enriched in both IL-10 knockout EPC-derived exosome as well as TNFα (tumor necrosis factor-α)-treated mouse cardiac endothelial cell-derived exosomes (TNFα inflamed mouse cardiac endothelial cell-derived exosome). ILK-enriched exosomes activated NF-κB (nuclear factor κB) pathway and NF-κB-dependent gene transcription in recipient endothelial cells and this effect was partly attenuated through ILK knockdown in exosomes. Intriguingly, ILK knockdown in IL-10 knockout EPC-derived exosome significantly rescued their reparative dysfunction in myocardial repair, improved left ventricle cardiac function, reduced MI scar size, and enhanced post-MI neovascularization in MI mouse model. Conclusions: IL-10 deficiency/inflammation alters EPC-derived exosome function, content and therapeutic effect on myocardial repair by upregulating ILK enrichment in exosomes, and ILK-mediated activation of NF-κB pathway in recipient cells, whereas ILK knockdown in exosomes attenuates NF-κB activation and reduces inflammatory response. Our study provides new understanding of how inflammation may alter stem cell-exosome-mediated cardiac repair and identifies ILK as a target kinase for improving progenitor cell exosome-based cardiac therapies.

Interleukin-22 promotes development of malignant lesions in a mouse model of spontaneous breast cancer.

Interleukin (IL)‐22 is recognized as a tumor‐supporting cytokine and is implicated in the proliferation of multiple epithelial cancers. In breast cancer, the current knowledge of IL‐22 function is based on cell line models and little is known about how IL‐22 affects the tumor initiation, proliferation, invasion, and metastasis in the in vivo system. Here, we investigated the tumor stage‐specific function of IL‐22 in disease development by evaluating the stage‐by‐stage progression of breast cancer in an IL‐22 knockout spontaneous breast cancer mouse model. We found that among all the stages, IL‐22 is specifically upregulated in tumor microenvironment (TME) during the malignant transformation stage of breast tumor progression. The deletion of IL‐22 gene leads to the arrest of malignant transition stage, and reduced invasion and tumor burden. Administration of recombinant IL‐22 in the TME does not influence in vivo tumor initiation and proliferation but only promotes malignant transformation of cancer cells. Mechanistically, deletion of IL‐22 gene causes downregulation of epithelial‐to‐mesenchymal transition (EMT)‐associated transcription factors in breast tumors, suggesting EMT as the mechanism of regulation of malignancy by IL‐22. Clinically, in human breast tumor tissues, increased number of IL‐22+ cells in the TME is associated with an aggressive phenotype of breast cancer. For the first time, this study provides an insight into the tumor stage‐specific function of IL‐22 in breast tumorigenesis.

Proliferation of Ly6C+ monocytes/macrophages contributes to their accumulation in mouse skin wounds.

Monocytes and macrophages (Mo/MΦ) play critical roles in all phases of skin wound healing. The majority of these cells are thought to be recruited from blood Mo; however, the role local proliferation of Mo/MΦ in the wound has not been defined. Therefore, we tested the hypothesis that local proliferation of Mo and/or MΦ contributes to their accumulation during wound healing. Male C57Bl/6 mice (N=4-9/group) were subjected to excisional skin wounding. Proliferating Mo/MΦ (F4/80+Ki67+) were observed in wound cryosections, peaking on day 5 post-wounding. Cell cycle analysis on cells isolated from skin tissue revealed that wounding increased both the number and percentage of inflammatory Ly6C+F4/80lo/- Mo/MΦ in the S/G2/M phases, peaking on day 6 post-wounding. In contrast, more mature Ly6C-F4/80+ cells were found predominantly in the G0 phase with less than 1% cells in S/G2/M phase following injury. In peripheral blood, Mo were very rarely found in the S/G2/M phase, suggesting that the wound environment triggered the Ly6C+F4/80lo/- Mo proliferative response. Furthermore, injury induced several potential regulators of proliferation in wounds, including IL-1β and IL-6, and wound Mo/MΦ expressed surface receptors for these cytokines. However, wound Mo/MΦ proliferation was not altered in IL-1R1 knockout (KO) or IL-6 KO mice. In summary, our findings indicate that proliferation contributes to Mo/MΦ accumulation in wounds and, contrary to findings in other pathophysiologic conditions, Ly6C+/F4/80lo/- Mo/MΦ proliferate during skin wound healing whereas mature Ly6C-F4/80+ MΦ do not.

IL-6-mediated hepatocyte production is the primary source of plasma and urine neutrophil gelatinase–associated lipocalin during acute kidney injury

Neutrophil gelatinase associated lipocalin (NGAL, Lcn2) is the most widely studied biomarker of acute kidney injury (AKI). Previous studies have demonstrated that NGAL is produced by the kidney and released into the urine and plasma. Consequently, NGAL is currently considered a tubule specific injury marker of AKI. However, the utility of NGAL to predict AKI has been variable suggesting that other mechanisms of production are present. IL-6 is a proinflammatory cytokine increased in plasma by two hours of AKI and mediates distant organ effects. Herein, we investigated the role of IL-6 in renal and extra-renal NGAL production. Wild type mice with ischemic AKI had increased plasma IL-6, increased hepatic NGAL mRNA, increased plasma NGAL, and increased urine NGAL; all reduced in IL-6 knockout mice. Intravenous IL-6 in normal mice increased hepatic NGAL mRNA, plasma NGAL and urine NGAL. In mice with hepatocyte specific NGAL deletion (Lcn2hep-/-) and ischemic AKI, hepatic NGAL mRNA was absent, and plasma and urine NGAL were reduced. Since urine NGAL levels appear to be dependent on plasma levels, the renal handling of circulating NGAL was examined using recombinant human NGAL. After intravenous recombinant human NGAL administration to mice, human NGAL in mouse urine was detected by ELISA during proximal tubular dysfunction, but not in pre-renal azotemia. Thus, during AKI, IL-6 mediates hepatic NGAL production, hepatocytes are the primary source of plasma and urine NGAL, and plasma NGAL appears in the urine during proximal tubule dysfunction. Hence, our data change the paradigm by which NGAL should be interpreted as a biomarker of AKI.

Impact of skeletal muscle IL-6 on subcutaneous and visceral adipose tissue metabolism immediately after high- and moderate-intensity exercises.

White adipose tissue is a major energy reserve for the body and is essential for providing fatty acids for other tissues when needed. Skeletal muscle interleukin-6 (IL-6) has been shown to be secreted from the working muscle and has been suggested to signal to adipose tissue and enhance lipolysis. The aim of the present study was to investigate the role of skeletal muscle IL-6 in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) lipolysis and glyceroneogenesis with prolonged moderate-intensity exercise and high-intensity exercise in mice. Female inducible muscle-specific IL-6 knockout (IL-6 iMKO) mice and littermate control (Floxed) mice performed a single exercise bout for either 120 min at 16 m/min and 10° slope (moderate intensity) or 30 min at 20 m/min and 10° slope (high intensity), or they remained rested (rest). Visceral and subcutaneous adipose tissues, quadriceps muscles, and blood were quickly obtained. Plasma IL-6 increased in Floxed mice but not in IL-6 iMKO mice with high-intensity exercise. VAT signal transducer and activator of transcription (STAT)3Tyr705 phosphorylation was lower, and VAT hormone-sensitive lipase (HSL)Ser563 phosphorylation was higher in IL-6 iMKO mice than in Floxed mice at rest. Furthermore, HSLSer563 and HSLSer660 phosphorylation increased in VAT and phosphoenolpyruvate carboxykinase protein decreased in SAT with moderate-intensity exercise in both genotypes. On the other hand, both exercise protocols increased pyruvate dehydrogenaseSer232 phosphorylation in VAT only in IL-6 iMKO mice and decreased tumor necrosis factor-α messenger RNA in SAT and VAT only in Floxed mice. In conclusion, the present findings suggest that skeletal muscle IL-6 regulates markers of lipolysis in VAT in the basal state and pyruvate availability for glyceroneogenesis in VAT with exercise. Moreover, skeletal muscle IL-6 may contribute to exercise-induced anti-inflammatory effects in SAT and VAT.

Prescription Opioids induce Gut Dysbiosis and Exacerbate Colitis in a Murine Model of Inflammatory Bowel Disease.

Opioids are the most prescribed analgesics for pain in inflammatory bowel diseases [IBD]; however, the consequences of opioid use on IBD severity are not well defined. This is the first study investigating consequences of hydromorphone in both dextran sodium sulphate [DSS]-induced colitis and spontaneous colitis (IL-10 knockout [IL-10-/-]) mouse models of IBD. To determine the consequences of opioids on IBD pathogenesis, wild-type [WT] mice were treated with clinically relevant doses of hydromorphone and colitis was induced via 3% DSS in drinking water for 5 days. In parallel we also determined the consequences of opioids in a spontaneous colitis model. Hydromorphone and DSS independently induced barrier dysfunction, bacterial translocation, disruption of tight junction organisation and increased intestinal and systemic inflammation, which were exacerbated in mice receiving hydromorphone in combination with DSS. Hydromorphone + DSS-treated mice exhibited significant microbial dysbiosis. Predictive metagenomic analysis of the gut microbiota revealed high abundance in the bacterial communities associated with virulence, antibiotic resistance, toxin production, and inflammatory properties. Hydromorphone modulates tight junction organisation in a myosin light chain kinase [MLCK]-dependent manner. Treatment with MLCK inhibitor ML-7 ameliorates the detrimental effects of hydromorphone on DSS-induced colitis and thus decreases severity of IBD. Similarly, we demonstrated that hydromorphone treatment in IL-10-/- mice resulted in accelerated clinical manifestations of colitis compared with control mice. Opioids used for pain management in IBD accelerate IBD progression by dysregulation of the gut microbiota, leading to expansion of pathogenic bacteria, translocation of bacteria, immune deregulation and sustained inflammation.

Long-Chain Polyphosphate Is a Potential Agent for Inducing Mucosal Healing of the Colon in Ulcerative Colitis.

The goal of ulcerative colitis (UC) treatment has recently been shown to be “mucosal healing,” as no drug directly induces mucosal healing. Probiotics possess sufficient safety, but their efficacy in the treatment of UC remains controversial because of the influence of intestinal conditions. It is believed that the identification of bioactive molecules produced by probiotics and their application will help to solve this issue. We therefore identified a probiotic‐derived long‐chain polyphosphate as a molecule enhancing the intestinal barrier function. This study demonstrated that long‐chain polyphosphate exhibited antiinflammatory effects in a human macrophage and interleukin‐10 knockout transfusion mouse model. The first‐in‐human trial showed that 7 of the 10 enrolled patients acquired clinical remission, 4 of whom achieved endoscopic remission despite a history of treatment with anti–tumor necrosis factor (TNF)–α agents. No adverse reactions were observed. Long‐chain polyphosphate might be useful for the treatment of refractory UC, even in patients with failure or intolerance to anti‐TNF‐α therapy.

HTLV-1 Dysregulates IL-6 and IL-10-JAK/STAT Signaling and Induces Leukemia/Lymphoma of Mature CD4+ T Cells with Regulatory T-Cell-like Signatures

Human T-cell leukemia virus, type 1 (HTLV-1) causes adult T-cell leukemia-lymphoma (ATL) and chronic inflammatory diseases (e.g., HTLV-1 associated myelopathy, uveitis). Among viral genes encoded in the HTLV-1 provirus, HTLV-1 bZIP factor (HBZ) is the most important gene for its pathogenesis, since HBZ is constantly expressed in all ATL cases, and has a potential to enhance T-cell proliferation. We generated HBZ transgenic (Tg) mice and found that almost all mice developed systemic inflammation, such as dermatitis, and about 40% of mice suffered from T-cell lymphoma. In addition, this mouse demonstrates the similar immunophenotypes to HTLV-1-infected subjects, such as increase of effector/memory and Foxp3-expressing regulatory T cells (Tregs), indicating that it is a good animal model to analyze the molecular mechanisms of pathogenesis by HTLV-1. There is a clear correlation between the severity of inflammation and the incidence of T-cell lymphoma, suggesting that some immune factors are closely involved in oncogenesis by HBZ. Recent studies showed that several pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-6 (IL-6), participate in not only inflammation but also tumor development. Especially, IL-6 has been reported to play important roles in oncogenesis, tumor progression, angiogenesis and migration. To clarify the roles of IL-6 in HBZ-mediated lymphomagenesis, we crossed HBZ-Tg mice with IL-6 knockout (KO) mice. Contrary to our hypothesis, inflammation was exacerbated, and incidence of T-cell lymphomas was markedly increased in HBZ-Tg/IL-6KO mice. In the pathological analysis of the lymphoma tissues, the percentage of Foxp3+ cells were much higher in HBZ-Tg/IL-6KO mice than in HBZ-Tg mice. Moreover, flow cytometric analysis also showed that CD4+Foxp3+ T cells were increased in spleens from HBZ-Tg/IL-6KO mice compared with HBZ-Tg mice or WT mice. Since IL-6 inhibits TGF-beta-induced Foxp3 expression and subsequently suppresses differentiation to Tregs, our results suggest that depletion of IL-6 induces aberrant differentiation of CD4+ T cells toward Treg-like cells in HBZ-Tg mice and accelerates lymphomagenesis of this subset. RNA-seq and flow cytometric analyses revealed that expression of IL-10 was significantly higher in CD4+ T cells of HBZ-Tg/IL-6KO than HBZ-Tg. Importantly, IL-10 accelerated the proliferation of CD4+ T cells of HBZ-Tg whereas it did not influence control T cells. We also found that HBZ interacted with both STAT1 and STAT3, which are critical transcription factors in IL-10-JAK/STAT signaling pathways, and enhanced their transcriptional activities. Foxp3-expressing T cells and IL-10 are known to be immune-suppressive, but these results indicate that increased Foxp3-expressing T cells and activation of IL-10-JAK/STAT signaling are associated with inflammation and lymphomagenesis by HBZ in vivo. Our results suggest that IL-6 and IL-10 have suppressive and promoting effects on HBZ-induced pathogenesis, respectively. It has been reported that progression of HTLV-1-associated diseases was observed in several HTLV-1 carriers after administration of anti-IL-6R antibody, Tocilizumab. Inhibition of IL-6/IL-6R signaling and consequent activation of Foxp3/IL-10/JAK/STAT axis seem to be important for HTLV-1 pathogenesis. Disclosures Ohshima: Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Celgene Corp.: Honoraria, Research Funding; NEC Corp.: Research Funding; SRL, Inc.: Consultancy. Matsuoka:Kyowa Kirin Co., Ltd.: Research Funding; Bristol-Myers Squibb Corp.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria.

Antibiotic-modulated microbiome suppresses lethal inflammation and prolongs lifespan in Treg-deficient mice

BackgroundRegulatory T cell (Treg) deficiency leads to IPEX syndrome, a lethal autoimmune disease, in Human and mice. Dysbiosis of the gut microbiota in Treg-deficient scurfy (SF) mice has been described, but to date, the role of the gut microbiota remains to be determined.ResultsTo examine how antibiotic-modified microbiota can inhibit Treg deficiency-induced lethal inflammation in SF mice, Treg-deficient SF mice were treated with three different antibiotics. Different antibiotics resulted in distinct microbiota and metabolome changes and led to varied efficacy in prolonging lifespan and reducing inflammation in the liver and lung. Moreover, antibiotics altered plasma levels of several cytokines, especially IL-6. By analyzing gut microbiota and metabolome, we determined the microbial and metabolomic signatures which were associated with the antibiotics. Remarkably, antibiotic treatments restored the levels of several primary and secondary bile acids, which significantly reduced IL-6 expression in RAW macrophages in vitro. IL-6 blockade prolonged lifespan and inhibited inflammation in the liver and lung. By using IL-6 knockout mice, we further identified that IL-6 deletion provided a significant portion of the protection against inflammation induced by Treg dysfunction.ConclusionOur results show that three antibiotics differentially prolong survival and inhibit lethal inflammation in association with a microbiota—IL-6 axis. This pathway presents a potential avenue for treating Treg deficiency-mediated autoimmune disorders.

Autophagy induction by rapamycin ameliorates experimental colitis and improves intestinal epithelial barrier function in IL-10 knockout mice

BackgroundAn impairment of the intestinal barrier function is one of the major characteristics of Crohn’s disease (CD). This study aimed to evaluate the impact of autophagy induction by rapamycin on the intestinal epithelial barrier function in CD model mice. MethodsIL-10 knockout (IL-10 KO) mice were used as the human CD models in this study. All the mice were randomly assigned into four groups, (a) wild-type (WT) group; (b) IL-10 KO group; (c) IL-10 KO + rapamycin group and (d) IL-10 KO + 3-methyladenine (3-MA), containing 6 mice in each group. The disease activity index (DAI), histology, pro-inflammatory cytokines and chemotactic factors in colon tissues, intestinal and colonic permeability, distributions and expressions of tight junction (TJ) proteins, epithelial apoptosis of mice in four groups were evaluated and compared. ResultsAutophagy induction by rapamycin treatment ameliorated DAI and histological colitis, decreased pro-inflammatory cytokines (TNF-α, IFN-γ and IL-17) and chemotactic factors (CXCL-1 and CXCL-2), decreased intestinal and colonic permeability, improved the distribution and expression of TJ proteins in IL-10 KO mice. ConclusionAutophagy induction by rapamycin significantly improved intestinal barrier function and protected IL-10 KO mice from the experimental chronic colitis.

Estrogen-induced compensatory mechanisms protect IL-10-deficient mice from developing EAE

BackgroundIL-10 knockout (KO) mice are protected from experimental autoimmune encephalomyelitis (EAE) with low-dose estrogen (E2) treatment similar to wild-type (WT) mice. Previous studies have demonstrated a decrease in tumor necrosis factor in all E2-treated groups, which led to the protection of the mice.MethodsThis study used IL-10 KO mice and WT mice treated either with E2 or sham pellets 7 days prior to induction of EAE. Mice were observed for 21 days post-immunization. The spleen, inguinal lymph nodes, and brain were evaluated by flow cytometry. Spinal cords were evaluated using a cytokine/chemokine array, RT-PCR, and histology.ResultsThis study demonstrates that E2 treatment induced three heightened regulatory mechanisms that potentially protect IL-10 KO mice from EAE: (1) an increase in programmed death-ligands 1 and 2 on monocytes and macrophages in the periphery and within the CNS; (2) an increase in CD73 in the inflamed CNS, which can increase the production of the anti-inflammatory molecule adenosine; and (3) a decrease in CD4+CD25+FoxP3+ regulatory T cells in the spleen. Together, these factors comprise an alternative compensatory mechanism that significantly downregulates key pro-inflammatory cytokine, chemokine, and chemokine receptor genes which are enhanced in the spinal cord of IL-10 KO mice. This group of E2-treated mice remained asymptomatic after EAE challenge similar to E2-treated WT mice, despite their having more T and B lymphocytes in the brain, and modestly increased demyelination in the spinal cord.ConclusionThese results indicate that previously unrecognized compensatory mechanisms of EAE protection are stimulated by E2 in the absence of IL-10, which can provide disease protection comparable to the IL-10-dependent effects induced by E2 in WT mice.