ABSTRACT
Alcohol-associated liver disease (ALD) is a serious public health problem with limited pharmacologic options. The goal of the current study was to investigate the efficacy of pharmacologic inhibition of soluble epoxide hydrolase (sEH), an enzyme involved in lipid metabolism, in experimental ALD, and to examine the underlying mechanisms. C57BL/6J male mice were subjected to acute-on-chronic ethanol (EtOH) feeding with or without the sEH inhibitor 4-[[trans-4-[[[[4-trifluoromethoxy phenyl]amino]carbonyl]-amino]cyclohexyl]oxy]-benzoic acid (TUCB). Liver injury was assessed by multiple end points. Liver epoxy fatty acids and dihydroxy fatty acids were measured by targeted metabolomics. Whole-liver RNA sequencing was performed, and free modified RNA bases were measured by mass spectrometry. EtOH-induced liver injury was ameliorated by TUCB treatment as evidenced by reduced plasma alanine aminotransferase levels and was associated with attenuated alcohol-induced endoplasmic reticulum stress, reduced neutrophil infiltration, and increased numbers of hepatic M2 macrophages. TUCB altered liver epoxy and dihydroxy fatty acids and led to a unique hepatic transcriptional profile characterized by decreased expression of genes involved in apoptosis, inflammation, fibrosis, and carcinogenesis. Several modified RNA bases were robustly changed by TUCB, including N6-methyladenosine and 2-methylthio-N6-threonylcarbamoyladenosine. These findings show the beneficial effects of sEH inhibition by TUCB in experimental EtOH-induced liver injury, warranting further mechanistic studies to explore the underlying mechanisms, and highlighting the translational potential of sEH as a drug target for this disease.
Subject(s)
Chemical and Drug Induced Liver Injury, Chronic , Liver Diseases, Alcoholic , Mice , Animals , Male , Epoxide Hydrolases/genetics , Epoxide Hydrolases/metabolism , Transcriptome , Mice, Inbred C57BL , Liver Diseases, Alcoholic/genetics , Fatty Acids , Ethanol , RNAABSTRACT
BACKGROUND AND AIMS: Intestinal farnesoid X receptor (FXR) plays a critical role in alcohol-associated liver disease (ALD). We aimed to investigate whether alcohol-induced dysbiosis increased intestinal microRNA194 (miR194) that suppressed Fxr transcription and whether Lactobacillus rhamnosus GG-derived exosome-like nanoparticles (LDNPs) protected against ALD through regulation of intestinal miR194-FXR signaling in mice. APPROACH AND RESULTS: Binge-on-chronic alcohol exposure mouse model was utilized. In addition to the decreased ligand-mediated FXR activation, alcohol feeding repressed intestinal Fxr transcription and increased miR194 expression. This transcriptional suppression of Fxr by miR194 was confirmed in intestinal epithelial Caco-2 cells and mouse enteriods. The alcohol feeding-reduced intestinal FXR activation was further demonstrated by the reduced FXR reporter activity in fecal samples and by the decreased fibroblast growth factor 15 (Fgf15) messenger RNA (mRNA) in intestine and protein levels in the serum, which caused an increased hepatic bile acid synthesis and lipogeneses. We further demonstrated that alcohol feeding increased-miR194 expression was mediated by taurine-upregulated gene 1 (Tug1) through gut microbiota regulation of taurine metabolism. Importantly, 3-day oral administration of LDNPs increased bile salt hydrolase (BSH)-harboring bacteria that decreased conjugated bile acids and increased gut taurine concentration, which upregulated Tug1, leading to a suppression of intestinal miR194 expression and recovery of FXR activation. Activated FXR upregulated FGF15 signaling and subsequently reduced hepatic bile acid synthesis and lipogenesis and attenuated ALD. These protective effects of LDNPs were eliminated in intestinal FxrΔIEC and Fgf15-/- mice. We further showed that miR194 was upregulated, whereas BSH activity and taurine levels were decreased in fecal samples of patients with ALD. CONCLUSIONS: Our results demonstrated that gut microbiota-mediated miR194 regulation contributes to ALD pathogenesis and to the protective effects of LDNPs through modulating intestinal FXR signaling.
Subject(s)
Liver Diseases, Alcoholic , MicroRNAs , Animals , Humans , Mice , Bile Acids and Salts/metabolism , Caco-2 Cells , Ethanol/pharmacology , Liver/pathology , Liver Diseases, Alcoholic/metabolism , Mice, Inbred C57BL , MicroRNAs/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Taurine/pharmacology , NanoparticlesABSTRACT
Bark protects the tree against environmental insults. Here, we analyzed whether this defensive strategy could be utilized to broadly enhance protection against colitis. As a proof of concept, we show that exosome-like nanoparticles (MBELNs) derived from edible mulberry bark confer protection against colitis in a mouse model by promoting heat shock protein family A (Hsp70) member 8 (HSPA8)-mediated activation of the AhR signaling pathway. Activation of this pathway in intestinal epithelial cells leads to the induction of COP9 Constitutive Photomorphogenic Homolog Subunit 8 (COPS8). Utilizing a gut epithelium-specific knockout of COPS8, we demonstrate that COPS8 acts downstream of the AhR pathway and is required for the protective effect of MBELNs by inducing an array of anti-microbial peptides. Our results indicate that MBELNs represent an undescribed mode of inter-kingdom communication in the mammalian intestine through an AhR-COPS8-mediated anti-inflammatory pathway. These data suggest that inflammatory pathways in a microbiota-enriched intestinal environment are regulated by COPS8 and that edible plant-derived ELNs may hold the potential as new agents for the prevention and treatment of gut-related inflammatory disease.
Subject(s)
Colitis , Exosomes , Morus , Nanoparticles , Animals , Colitis/chemically induced , Colitis/metabolism , Colitis/prevention & control , Disease Models, Animal , Exosomes/metabolism , Mice , Mice, Inbred C57BL , Plant Bark/metabolismABSTRACT
BACKGROUND AND AIMS: Chronic alcohol consumption is accompanied by intestinal inflammation. However, little is known about how alterations to the intestinal immune system and sphingolipids contribute to the pathogenesis of alcohol-associated liver disease (ALD). APPROACH AND RESULTS: We used wild-type mice, retinoid-related orphan receptor gamma t (RORγt)-deficient mice, sphingosine kinase-deficient mice, and local gut anti-inflammatory, 5-aminosalicyclic acid-treated mice in a chronic-binge ethanol feeding model. Targeted lipidomics assessed the sphingolipids in gut and liver samples. Gut immune cell populations, the amounts of sphingolipids, and the level of liver injury were examined. Alcohol intake induces a pro-inflammatory shift in immune cell populations in the gut, including an increase in Th17 cells. Using RORγt-deficient mice, we found that Th17 cells are required for alcohol-associated gut inflammation and the development of ALD. Treatment with 5-aminosalicyclic acid decreases alcohol-induced liver injury and reverses gut inflammation by the suppression of CD4+ /RORγt+ /interleukin-17A+ cells. Increased Th17 cells were due to up-regulation of sphingosine kinase 1 activity and RORγt activation. We found that S1P/S1PR1 signaling is required for the development of Th17 cell-mediated ALD. Importantly, in vivo intervention blocking of S1P/S1PR1 signaling markedly attenuated alcohol-induced liver inflammation, steatosis, and damage. CONCLUSIONS: Gut inflammation is a functional alteration of immune cells in ALD. Reducing gut Th17 cells leads to reduced liver damage. S1P signaling was crucial in the pathogenesis of ALD in a Th17 cell-dependent manner. Furthermore, our findings suggest that compounds that reduce gut inflammation locally may represent a unique targeted approach in the treatment of ALD.
Subject(s)
Ethanol/adverse effects , Fatty Liver, Alcoholic/prevention & control , Lysophospholipids/pharmacology , Sphingosine/analogs & derivatives , Th17 Cells/physiology , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Disease Models, Animal , Fatty Liver, Alcoholic/etiology , Female , Intestines/cytology , Intestines/drug effects , Intestines/immunology , Male , Mesalamine/pharmacology , Mesalamine/therapeutic use , Mice , Mice, Inbred C57BL , Mice, Knockout , Sphingosine/pharmacology , Th17 Cells/drug effectsABSTRACT
BACKGROUND AND AIMS: Nonalcoholic steatohepatitis (NASH) is associated with obesity and an increased risk for liver cirrhosis and cancer. Neutral ceramidase (NcDase), which is highly expressed in the intestinal brush border of the small intestine, plays a critical role in digesting dietary sphingolipids (ceramide) to regulate the balance of sphingosine and free fatty acids. It remains unresolved whether obesity-associated alteration of NcDase contributes to the manifestation of NASH. Here, we revealed that NcDase deficiency in murine models of NASH prevents hepatic inflammation and fibrosis but not steatosis. APPROACH AND RESULTS: NcDase-/- mice display reduced stearoyl-CoA desaturase (SCD) 1 expression with a compositional decrease of monounsaturated fatty acids (MUFAs) under the different dietary conditions. We further found that NcDase is a functional regulator of intestinal B cells and influences the abundance and quality of the secretory IgA response toward commensal bacteria. Analysis of composition of the gut microbiota found that Clostridiales colonization was increased in NcDase-/- mice. The colonization of germ-free mice with gut microbiota from NcDase-/- mice resulted in a greater decrease in the expression of SCD1 and the level of MUFAs in the liver relative to gut microbiota from wild-type littermates, which are associated with the alternation of IgA-bound bacteria, including increase of Ruminococcaceae and reduction of Desulfovibrio. Mechanistically, NcDase is a crucial link that controls the expression of SCD1 and MUFA-mediated activation of the Wnt/ß-catenin. Very importantly, our experiments further demonstrated that Wnt3a stimulation can enhance the activity of NcDase in hepatocytes. CONCLUSIONS: Thus, the NcDase-SCD1-Wnt feedback loop promotes the diet-induced steatohepatitis and fibrosis through the regulation of intestinal IgA+ immune cells.
Subject(s)
B-Lymphocytes/physiology , Fatty Acids, Monounsaturated/metabolism , Immunoglobulin A/metabolism , Intestinal Mucosa/metabolism , Neutral Ceramidase/physiology , Non-alcoholic Fatty Liver Disease/metabolism , Animals , B-Lymphocytes/metabolism , Disease Models, Animal , Gastrointestinal Microbiome/immunology , Intestinal Mucosa/cytology , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neutral Ceramidase/deficiency , Neutral Ceramidase/metabolism , Obesity/metabolismABSTRACT
Alcoholic liver disease (ALD) is associated with gut dysbiosis and hepatic inflammasome activation. While it is known that antimicrobial peptides (AMPs) play a critical role in the regulation of bacterial homeostasis in ALD, the functional role of AMPs in the alcohol-induced inflammasome activation is unclear. The aim of this study was to determine the effects of cathelicidin-related antimicrobial peptide (CRAMP) on inflammasome activation in ALD. CRAMP knockout (Camp-/-) and wild-type (WT) mice were subjected to binge-on-chronic alcohol feeding and synthetic CRAMP peptide was administered. Serum/plasma and hepatic tissue samples from human subjects with alcohol use disorder and/or alcoholic hepatitis were analyzed. CRAMP deficiency exacerbated ALD with enhanced inflammasome activation as shown by elevated serum interleukin (IL)-1ß levels. Although Camp-/- mice had comparable serum endotoxin levels compared to WT mice after alcohol feeding, hepatic lipopolysaccharide (LPS) binding protein (LBP) and cluster of differentiation (CD) 14 were increased. Serum levels of uric acid (UA), a Signal 2 molecule in inflammasome activation, were positively correlated with serum levels of IL-1ß in alcohol use disorder patients with ALD and were increased in Camp-/- mice fed alcohol. In vitro studies showed that CRAMP peptide inhibited LPS binding to macrophages and inflammasome activation stimulated by a combination of LPS and UA. Synthetic CRAMP peptide administration decreased serum UA and IL-1ß concentrations and rescued the liver from alcohol-induced damage in both WT and Camp-/- mice. In summary, CRAMP exhibited a protective role against binge-on-chronic alcohol-induced liver damage via regulation of inflammasome activation by decreasing LPS binding and UA production. CRAMP administration may represent a novel strategy for treating ALD. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Subject(s)
Antimicrobial Cationic Peptides/metabolism , Inflammasomes/metabolism , Liver Diseases, Alcoholic/metabolism , Liver/metabolism , Animals , Antimicrobial Cationic Peptides/genetics , Biomarkers/blood , Dysbiosis/genetics , Dysbiosis/metabolism , Dysbiosis/pathology , Humans , Inflammasomes/genetics , Interleukin-1beta/blood , Liver/pathology , Liver Diseases, Alcoholic/genetics , Liver Diseases, Alcoholic/pathology , Male , Mice , Mice, Knockout , Oxidative Stress/genetics , Uric Acid/blood , CathelicidinsABSTRACT
The intestinal immune system is continuously exposed to massive amounts of nanoparticles derived from food. Whether nanoparticles from plants we eat daily have a role in maintaining intestinal immune homeostasis is poorly defined. Here, we present evidence supporting our hypothesis that edible nanoparticles regulate intestinal immune homeostasis by targeting dendritic cells (DCs). Using three mouse colitis models, our data show that orally given nanoparticles isolated from broccoli extracts protect mice against colitis. Broccoli-derived nanoparticle (BDN)-mediated activation of adenosine monophosphate-activated protein kinase (AMPK) in DCs plays a role in not only prevention of DC activation but also induction of tolerant DCs. Adoptively transferring DCs pre-pulsed with total BDN lipids, but not sulforaphane (SFN)-depleted BDN lipids, prevented DSS-induced colitis in C57BL/6 (B6) mice, supporting the role of BDN SFN in the induction of DC tolerance. Adoptively transferring AMPK+/+, but not AMPK-/-, DCs pre-pulsed with SFN prevented DSS-induced colitis in B6 mice, further supporting the DC AMPK role in SFN-mediated prevention of DSS-induced colitis. This finding could open new preventive or therapeutic avenues to address intestinal-related inflammatory diseases via activating AMPK.
Subject(s)
AMP-Activated Protein Kinases/genetics , Anti-Inflammatory Agents/pharmacology , Brassica/chemistry , Colitis, Ulcerative/prevention & control , Dendritic Cells/drug effects , Nanoparticles/chemistry , AMP-Activated Protein Kinases/metabolism , Administration, Oral , Adoptive Transfer , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/metabolism , Colitis, Ulcerative/chemically induced , Colitis, Ulcerative/immunology , Colitis, Ulcerative/pathology , Dendritic Cells/immunology , Dendritic Cells/pathology , Dendritic Cells/transplantation , Disease Models, Animal , Enzyme Activation/drug effects , Gene Expression , Humans , Immune Tolerance , Isothiocyanates/chemistry , Lipids/isolation & purification , Lipids/pharmacology , Mice , Mice, Inbred C57BL , Nanoparticles/administration & dosage , Plant Extracts/chemistry , Sodium Dodecyl Sulfate , SulfoxidesABSTRACT
The lack of access to the brain is a major obstacle for central nervous system drug development. In this study, we demonstrate the capability of a grapefruit-derived nanovector (GNV) to carry miR17 for therapeutic treatment of mouse brain tumor. We show that GNVs coated with folic acid (FA-GNVs) are enhanced for targeting the GNVs to a folate receptor-positive GL-26 brain tumor. Additionally, FA-GNV-coated polyethylenimine (FA-pGNVs) not only enhance the capacity to carry RNA, but the toxicity of the polyethylenimine is eliminated by the GNVs. Intranasal administration of miR17 carried by FA-pGNVs led to rapid delivery of miR17 to the brain that was selectively taken up by GL-26 tumor cells. Mice treated intranasally with FA-pGNV/miR17 had delayed brain tumor growth. Our results demonstrate that this strategy may provide a noninvasive therapeutic approach for treating brain-related disease through intranasal delivery.
Subject(s)
Brain Neoplasms/therapy , Citrus paradisi/chemistry , Genetic Therapy/methods , MicroRNAs/administration & dosage , MicroRNAs/genetics , Nanoparticles/chemistry , Administration, Intranasal , Animals , Brain Neoplasms/genetics , Cell Line, Tumor , Disease Progression , Folic Acid/therapeutic use , Mice , Nanoparticles/administration & dosage , Organ Specificity , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Polyethyleneimine/chemistry , Treatment Outcome , Xenograft Model Antitumor AssaysABSTRACT
Regulation and induction of anergy in NKT cells of the liver can inhibit autoimmune and antitumor responses by mechanisms that are poorly understood. We investigated the effects of PGE2, delivered by intestinal, mucus-derived, exosome-like nanoparticles (IDENs), on NKT cells in mice. In this study, we demonstrate that IDENs migrate to the liver where they induce NKT cell anergy. These effects were mediated by an IDENs' PGE2. Blocking PGE2 synthesis attenuated IDENs inhibition of induction of IFN-γ and IL-4 by α-galactosylceramide (α-GalCer)-stimulated liver NKT cells in a PGE2 E-type prostanoid 2/E-type prostanoid 4 receptor-mediated manner. Proinflammatory conditions enhanced the migration of IDENs to the liver where α-GalCer and PGE2 induced NKT anergy in response to subsequent α-GalCer stimulation. These findings demonstrate that IDENs carrying PGE2 can be transferred from the intestine to the liver, where they act as immune modulators, inducing an anergic-like state of NKT cells. These reagents might be developed as therapeutics for autoimmune liver diseases.
Subject(s)
Cell-Derived Microparticles/metabolism , Dinoprostone/metabolism , Exosomes/metabolism , Intestinal Mucosa/metabolism , Liver/immunology , Lymphocyte Activation/immunology , Natural Killer T-Cells/immunology , Animals , Clonal Anergy/immunology , Cyclic AMP/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Disease Models, Animal , Exosomes/immunology , Galactosylceramides/immunology , Hepatitis, Autoimmune/immunology , Hepatitis, Autoimmune/metabolism , Humans , Intestinal Mucosa/immunology , Liver/metabolism , Male , Mice , Signal TransductionABSTRACT
The gut mucosal immune system is considered to play an important role in counteracting potential adverse effects of food-derived antigens including nanovesicles. Whether nanovesicles naturally released from edible fruit work in a coordinated manner with gut immune cells to maintain the gut in a noninflammatory status is not known. Here, as proof of concept, we demonstrate that grapefruit-derived nanovesicles (GDNs) are selectively taken up by intestinal macrophages and ameliorate dextran sulfate sodium (DSS)-induced mouse colitis. These effects were mediated by upregulating the expression of heme oxygenase-1 (HO-1) and inhibiting the production of IL-1ß and TNF-α in intestinal macrophages. The inherent biocompatibility and biodegradability, stability at wide ranges of pH values, and targeting of intestinal macrophages led us to further develop a novel GDN-based oral delivery system. Incorporating methotrexate (MTX), an anti-inflammatory drug, into GDNs and delivering the MTX-GDNs to mice significantly lowered the MTX toxicity when compared with free MTX, and remarkably increased its therapeutic effects in DSS-induced mouse colitis. These findings demonstrate that GDNs can serve as immune modulators in the intestine, maintain intestinal macrophage homeostasis, and can be developed for oral delivery of small molecule drugs to attenuate inflammatory responses in human disease.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Citrus paradisi/chemistry , Colitis/drug therapy , Drug Delivery Systems/methods , Intestinal Mucosa/metabolism , Methotrexate/administration & dosage , Nanostructures/administration & dosage , Plant Extracts/administration & dosage , Animals , Colitis/chemically induced , Dextran Sulfate , Disease Models, Animal , Gene Expression Regulation , Heme Oxygenase-1/metabolism , Humans , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/immunology , Interleukin-1beta/immunology , Macrophages/immunology , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Molecular Targeted Therapy , Tumor Necrosis Factor-alpha/metabolismABSTRACT
UNLABELLED: The Wnt/ß-catenin pathway has been known to play a role in induction of immune tolerance, but its role in the induction and maintenance of natural killer T (NKT) cell anergy is unknown. We found that activation of the Wnt pathways in the liver microenvironment is important for induction of NKT cell anergy. We identified a number of stimuli triggering Wnt/ß-catenin pathway activation, including exogenous NKT cell activator, glycolipid α-GalCer, and endogenous prostaglandin E2 (PGE2). Glycolipid α-GalCer treatment of mice induced the expression of wnt3a and wnt5a in the liver and subsequently resulted in a liver microenvironment that induced NKT cell anergy to α-GalCer restimulation. We also found that circulating PGE2 carried by nanoparticles is stable, and that these nanoparticles are A33(+) . A33(+) is a marker of intestinal epithelial cells, which suggests that the nanoparticles are derived from the intestine. Mice treated with PGE2 associated with intestinal mucus-derived exosome-like nanoparticles (IDENs) induced NKT cell anergy. PGE2 treatment leads to activation of the Wnt/ß-catenin pathway by inactivation of glycogen synthase kinase 3ß of NKT cells. IDEN-associated PGE2 also induces NKT cell anergy through modification of the ability of dendritic cells to induce interleukin-12 and interferon-ß in the context of both glycolipid presentation and Toll-like receptor-mediated pathways. CONCLUSION: These findings demonstrate that IDEN-associated PGE2 serves as an endogenous immune modulator between the liver and intestines and maintains liver NKT cell homeostasis. This finding has implications for development of NKT cell-based immunotherapies. (HEPATOLOGY 2013).
Subject(s)
Intestinal Mucosa/immunology , Killer Cells, Natural/immunology , Liver/immunology , Wnt Proteins/metabolism , Wnt3A Protein/metabolism , beta Catenin/metabolism , Animals , Cellular Microenvironment/immunology , Clonal Anergy/drug effects , Clonal Anergy/immunology , Dinoprostone/immunology , Dinoprostone/metabolism , Galactosylceramides/pharmacology , Immune Tolerance/immunology , Intestinal Mucosa/cytology , Intestinal Mucosa/metabolism , Killer Cells, Natural/metabolism , Liver/metabolism , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, SCID , Mucus/immunology , Mucus/metabolism , Nanoparticles , Wnt Proteins/immunology , Wnt Signaling Pathway/drug effects , Wnt Signaling Pathway/immunology , Wnt-5a Protein , Wnt3A Protein/immunology , beta Catenin/immunologyABSTRACT
Understanding the long-term effects and possible toxicity of nanoceria, a widely utilized commercial metal oxide, is of particular importance as it is poised for development as a therapeutic agent based on its autocatalytic redox behavior. We show here evidence of acute and subacute adverse hepatic responses, after a single infusion of an aqueous dispersion of 85 mg/kg, 30 nm nanoceria into Sprague Dawley rats. Light and electron microscopic evidence of avid uptake of nanoceria by Kupffer cells was detected as early as 1 hr after infusion. Biopersistent nanoceria stimulated cluster of differentiation 3(+) lymphocyte proliferation that intermingled with nanoceria-containing Kupffer cells to form granulomata that were observed between days 30 and 90. Ultrastructural tracking of ceria nanoparticles revealed aggregated nanoceria in phagolysosomes. An increased formation of small nanoceria over time observed in the latter suggests possible dissolution and precipitation of nanoceria. However, the pathway for nanoceria metabolism/secretion remains unclear. Although frank hepatic necrosis was not observed, the retention of nanoceria increased hepatic apoptosis acutely, this persisted to day 90. These findings, together with our earlier reports of 5-nm ceria-induced liver toxicity, provide additional guidance for nanoceria development as a therapeutic agent and for its risk assessment.
Subject(s)
Cerium/administration & dosage , Cerium/toxicity , Liver/drug effects , Liver/pathology , Animals , Apoptosis/drug effects , CD3 Complex , Cell Proliferation/drug effects , Immunohistochemistry , In Situ Nick-End Labeling , Kupffer Cells/chemistry , Kupffer Cells/drug effects , Liver/cytology , Male , Rats , Rats, Sprague-DawleyABSTRACT
Food-derived exosome-like nanoparticles pass through the intestinal tract throughout our lives, but little is known about their impact or function. Here, as a proof of concept, we show that the cells targeted by grape exosome-like nanoparticles (GELNs) are intestinal stem cells whose responses underlie the GELN-mediated intestinal tissue remodeling and protection against dextran sulfate sodium (DSS)-induced colitis. This finding is further supported by the fact that coculturing of crypt or sorted Lgr5⺠stem cells with GELNs markedly improved organoid formation. GELN lipids play a role in induction of Lgr5⺠stem cells, and the liposome-like nanoparticles (LLNs) assembled with lipids from GELNs are required for in vivo targeting of intestinal stem cells. Blocking ß-catenin-mediated signaling pathways of GELN recipient cells attenuates the production of Lgr5⺠stem cells. Thus, GELNs not only modulate intestinal tissue renewal processes, but can participate in the remodeling of it in response to pathological triggers.
Subject(s)
Colitis/chemically induced , Colitis/prevention & control , Dextran Sulfate/toxicity , Intestines/cytology , Nanoparticles/therapeutic use , Stem Cells/cytology , Vitis/chemistry , Animals , Male , MiceABSTRACT
The tumor microenvironment is reprogrammed by cancer cells and participates in all stages of tumor progression. Neutral ceramidase is a key regulator of ceramide, the central intermediate in sphingolipid metabolism. The contribution of neutral ceramidase to the reprogramming of the tumor microenvironment is not well understood. Here, we find that deletion of neutral ceramidase in multiple breast cancer models in female mice accelerates tumor growth. Our result show that Ly6C+CD39+ tumor-infiltrating CD8 T cells are enriched in the tumor microenvironment and display an exhausted phenotype. Deletion of myeloid neutral ceramidase in vivo and in vitro induces exhaustion in tumor-infiltrating Ly6C+CD39+CD8+ T cells. Mechanistically, myeloid neutral ceramidase is required for the generation of lipid droplets and for the induction of lipolysis, which generate fatty acids for fatty-acid oxidation and orchestrate macrophage metabolism. Metabolite ceramide leads to reprogramming of macrophages toward immune suppressive TREM2+ tumor associated macrophages, which promote CD8 T cells exhaustion.
Subject(s)
Neoplasms , Neutral Ceramidase , Animals , Female , Mice , CD8-Positive T-Lymphocytes/metabolism , Ceramides/metabolism , Macrophages/metabolism , Metabolic Reprogramming , Neutral Ceramidase/metabolism , Tumor MicroenvironmentABSTRACT
Exosomes participate in intercellular communication, but most data published are based on exosomes released from in vitro cultured cells that do not communicate with neighboring cells located in the same microenvironment as the exosomal-producing cells in vivo. In this study, our data show that co-culture of leukocytes isolated from breast tumor tissue leads to uptake of fibronectin (FN) on or in the tumor exosomes (Exo(fib+)). The induction of FN and exosomal uptake is tumor tissue derived and leukocyte specific, because leukocytes isolated from the peripheral blood of naïve mice failed to induce FN uptake by tumor exosomes. Furthermore, depletion of both CD25(+) cells and Gr-1(+) cells from tumor-associated leukocytes causes a reduction of Exo(fib+), suggesting that tumor-associated CD25(+) cells and Gr-1(+) cells participate in FN production and uptake by tumor exosomes, resulting in Exo(fib+). As a result of tumor cells absorbing Exo(fib+), two major events are induced: focal adhesion kinase/Src-dependent signaling pathways are activated, and the production of proinflammatory cytokines and metalloproteinase 9 is enhanced in response to absorbing exosomes. This, in turn, enhances tumor cell invasion in vitro and in vivo. Collectively, our findings provide evidence that exosomes released from freshly excised tumor tissue cells that have communicated/interacted with immune cells gain new immune evasion capacity.
Subject(s)
Cell Communication/physiology , Colonic Neoplasms/physiopathology , Exosomes/physiology , Fibronectins/metabolism , Leukocytes/physiology , Animals , Breast Neoplasms/physiopathology , Cell Line, Tumor , Disease Progression , Female , Lung Neoplasms/physiopathology , Lung Neoplasms/secondary , Mice , Mice, Inbred BALB C , Neoplasm Invasiveness/physiopathology , Neoplasm Metastasis , Neoplasm Transplantation , Tumor Microenvironment/physiologyABSTRACT
COP9 plays a role in plant innate immunity. The role of COP9 in mammalian innate immune responses is unknown. Here, we show that the COP9 signalosome subunit 5 (CSN5) is required for activation of proinflammatory kinases p38 and Erk and for down-regulation of the expression of genes regulated by nuclear factor E2-related factor 2. Mice with myeloid-specific CSN5 deficiency have lower mortality in polymicrobial sepsis. CSN5 is required for both Toll-like receptor (TLR) and reactive oxygen species-mediated deneddylation of Cul3, which is essential for Cul3/Keap1-mediated degradation of nuclear factor E2-related factor 2. On the basis of our results COP9 subunit CSN5 is considered to be an essential component of mammalian innate immunity.
Subject(s)
Immunity, Innate , Intracellular Signaling Peptides and Proteins/immunology , Macrophages/immunology , Peptide Hydrolases/immunology , Animals , Antioxidants/metabolism , COP9 Signalosome Complex , Cullin Proteins/metabolism , Female , Intracellular Signaling Peptides and Proteins/deficiency , Intracellular Signaling Peptides and Proteins/genetics , Lung/immunology , Lung/metabolism , Lung/pathology , MAP Kinase Signaling System , Macrophage Activation , Macrophages/metabolism , Male , Mice , Mice, Knockout , NF-E2-Related Factor 2/metabolism , Peptide Hydrolases/deficiency , Peptide Hydrolases/genetics , Shock, Septic/immunology , Shock, Septic/metabolism , Signal Transduction , Toll-Like Receptors/metabolism , Up-RegulationABSTRACT
The mechanism underlying the autoimmune polyglandular syndrome type-1 (APS1) has been attributed to defective T-cell negative selection resulting from reduced expression and presentation of autoantigens in thymic medullary epithelial cells (MECs). It has also been postulated that Aire is involved in development of regulatory T cells, although supporting evidence is lacking. Here we show that expression of Aire in MECs is required for development of iNKT cells, suggesting a role for iNKT cells in APS1.
Subject(s)
Killer Cells, Natural/physiology , Polyendocrinopathies, Autoimmune/immunology , T-Lymphocyte Subsets/physiology , Transcription Factors/immunology , Animals , Antigens, CD/immunology , Cells, Cultured , Epithelial Cells/cytology , Epithelial Cells/immunology , Killer Cells, Natural/cytology , Killer Cells, Natural/immunology , Liver/cytology , Mice , Mice, Knockout , Spleen/cytology , T-Lymphocyte Subsets/cytology , T-Lymphocyte Subsets/immunology , Thymus Gland/cytology , Transcription Factors/genetics , AIRE ProteinABSTRACT
Chronic alcohol ingestion promotes acute lung injury and impairs immune function. However, the mechanisms involved are incompletely understood. Here, we show that alcohol feeding enhances bleomycin-induced lung fibrosis and inflammation via the regulation of type 2 innate immune responses, especially by group 2 innate lymphoid cells (ILC2s). Neuroimmune interactions have emerged as critical modulators of lung inflammation. We found alcohol consumption induced the accumulation of ILC2 and reduced the production of the neuropeptide calcitonin gene-related peptide (CGRP), primarily released from sensory nerves and pulmonary neuroendocrine cells (PNECs). CGRP potently suppressed alcohol-driven type 2 cytokine signals in vivo. Vagal ganglia TRPV1+ afferents mediated immunosuppression occurs through the release of CGRP. Inactivation of the TRPV1 receptor enhanced bleomycin-induced fibrosis. In addition, mice lacking the CGRP receptor had the increased lung inflammation and fibrosis and type 2 cytokine production as well as exaggerated responses to alcohol feeding. Together, these data indicate that alcohol consumption regulates the interaction of CGRP and ILC2, which is a critical contributor of lung inflammation and fibrosis.
Subject(s)
Pneumonia , Pulmonary Fibrosis , Mice , Animals , Calcitonin Gene-Related Peptide , Immunity, Innate , Lymphocytes , Mice, Knockout , Cytokines , Fibrosis , Bleomycin , Ethanol/adverse effectsABSTRACT
Interactions between the enteric nervous system (ENS) and intestinal epithelium are thought to play a vital role in intestinal homeostasis. How the ENS monitors the frontier with commensal and pathogenic microbes while maintaining epithelial function remains unclear. Here, by combining subdiaphragmatic vagotomy with transcriptomics, chemogenetic strategy, and coculture of enteric neuron-intestinal organoid, we show that enteric neurons expressing VIP shape the α1,2-fucosylation of intestinal epithelial cells (IECs). Mechanistically, neuropeptide VIP activates fut2 expression via the Erk1/2-c-Fos pathway through the VIPR1 receptor on IECs. We further demonstrate that perturbation of enteric neurons leads to gut dysbiosis through α1,2-fucosylation in the steady state and results in increased susceptibility to alcohol-associated liver disease (ALD). This was attributed to an imbalance between beneficial Bifidobacterium and opportunistic pathogenic Enterococcus faecalis in ALD. In addition, Bifidobacterium α1,2-fucosidase may promote Bifidobacterium adhesion to the mucosal surface, which restricts Enterococcus faecalis overgrowth and prevents ALD progression.