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Aust AC, Benesova E, Vidova V, Coufalikova K, Smetanova S, Borek I, Janku P, Budinska E, Klanova J, Thon V, Spacil Z. Profiling Tryptophan Catabolites of Human Gut Microbiota and Acute-Phase Protein Levels in Neonatal Dried Blood Specimens. Front Microbiol 2021; 12:665743. [PMID: 34777268 PMCID: PMC8581761 DOI: 10.3389/fmicb.2021.665743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 09/16/2021] [Indexed: 11/21/2022] Open
Abstract
National screening programs use dried blood specimens to detect metabolic disorders or aberrant protein functions that are not clinically evident in the neonatal period. Similarly, gut microbiota metabolites and immunological acute-phase proteins may reveal latent immune aberrations. Microbial metabolites interact with xenobiotic receptors (i.e., aryl hydrocarbon and pregnane-X) to maintain gastrointestinal tissue health, supported by acute-phase proteins, functioning as sensors of microbial immunomodulation and homeostasis. The delivery (vaginal or cesarean section) shapes the microbial colonization, which substantially modulates both the immune system’s response and mucosal homeostasis. This study profiled microbial metabolites of the kynurenine and tryptophan pathway and acute-phase proteins in 134 neonatal dried blood specimens. We newly established neonatal blood levels of microbial xenobiotic receptors ligands (i.e., indole-3-aldehyde, indole-3-butyric acid, and indole-3-acetamide) on the second day of life. Furthermore, we observed diverse microbial metabolic profiles in neonates born vaginally and via cesarean section, potentially due to microbial immunomodulatory influence. In summary, these findings suggest the supportive role of human gut microbiota in developing and maintaining immune system homeostasis.
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Affiliation(s)
| | - Eliska Benesova
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | - Veronika Vidova
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | | | - Sona Smetanova
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | - Ivo Borek
- Department of Pediatrics, University Hospital Brno and Masaryk University Medical School, Brno, Czechia
| | - Petr Janku
- Department of Gynecology and Obstetrics, University Hospital Brno and Masaryk University Medical School, Brno, Czechia
| | - Eva Budinska
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | - Jana Klanova
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | - Vojtech Thon
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | - Zdenek Spacil
- RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
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52
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Wee HN, Liu JJ, Ching J, Kovalik JP, Lim SC. The Kynurenine Pathway in Acute Kidney Injury and Chronic Kidney Disease. Am J Nephrol 2021; 52:771-787. [PMID: 34753140 PMCID: PMC8743908 DOI: 10.1159/000519811] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/15/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND The kynurenine pathway (KP) is the major catabolic pathway for tryptophan degradation. The KP plays an important role as the sole de novo nicotinamide adenine dinucleotide (NAD+) biosynthetic pathway in normal human physiology and functions as a counter-regulatory mechanism to mitigate immune responses during inflammation. Although the KP has been implicated in a variety of disorders including Huntington's disease, seizures, cardiovascular disease, and osteoporosis, its role in renal diseases is seldom discussed. SUMMARY This review summarizes the roles of the KP and its metabolites in acute kidney injury (AKI) and chronic kidney disease (CKD) based on current literature evidence. Metabolomics studies demonstrated that the KP metabolites were significantly altered in patients and animal models with AKI or CKD. The diagnostic and prognostic values of the KP metabolites in AKI and CKD were highlighted in cross-sectional and longitudinal human observational studies. The biological impact of the KP on the pathophysiology of AKI and CKD has been studied in experimental models of different etiologies. In particular, the activation of the KP was found to confer protection in animal models of glomerulonephritis, and its immunomodulatory mechanism may involve the regulation of T cell subsets such as Th17 and regulatory T cells. Manipulation of the KP to increase NAD+ production or diversion toward specific KP metabolites was also found to be beneficial in animal models of AKI. Key Messages: KP metabolites are reported to be dysregulated in human observational and animal experimental studies of AKI and CKD. In AKI, the magnitude and direction of changes in the KP depend on the etiology of the damage. In CKD, KP metabolites are altered with the onset and progression of CKD all the way to advanced stages of the disease, including uremia and its related vascular complications. The activation of the KP and diversion to specific sub-branches are currently being explored as therapeutic strategies in these diseases, especially with regards to the immunomodulatory effects of certain KP metabolites. Further elucidation of the KP may hold promise for the development of biomarkers and targeted therapies for these kidney diseases.
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Affiliation(s)
| | - Jian-Jun Liu
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Jianhong Ching
- Duke-NUS Medical School, Singapore, Singapore
- KK Research Centre, KK Women's and Children's Hospital, Singapore, Singapore
| | | | - Su Chi Lim
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
- Diabetes Centre, Admiralty Medical Centre, Singapore, Singapore
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53
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Han H, Safe S, Jayaraman A, Chapkin RS. Diet-Host-Microbiota Interactions Shape Aryl Hydrocarbon Receptor Ligand Production to Modulate Intestinal Homeostasis. Annu Rev Nutr 2021; 41:455-478. [PMID: 34633858 PMCID: PMC8667662 DOI: 10.1146/annurev-nutr-043020-090050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated basic-helix-loop-helix transcription factor that binds structurally diverse ligands and senses cues from environmental toxicants and physiologically relevant dietary/microbiota-derived ligands. The AhR is an ancient conserved protein and is widely expressed across different tissues in vertebrates and invertebrates. AhR signaling mediates a wide range of cellular functions in a ligand-, cell type-, species-, and context-specific manner. Dysregulation of AhR signaling is linked to many developmental defects and chronic diseases. In this review, we discuss the emerging role of AhR signaling in mediating bidirectional host-microbiome interactions. We also consider evidence showing the potential for the dietary/microbial enhancement ofhealth-promoting AhR ligands to improve clinical pathway management in the context of inflammatory bowel diseases and colon tumorigenesis.
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Affiliation(s)
- Huajun Han
- Program in Integrative Nutrition and Complex Diseases and Department of Nutrition, Texas A&M University, College Station, Texas 77843, USA;
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Stephen Safe
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, USA
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843, USA
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases and Department of Nutrition, Texas A&M University, College Station, Texas 77843, USA;
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, USA
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54
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Eshleman EM, Alenghat T. Epithelial sensing of microbiota-derived signals. Genes Immun 2021; 22:237-246. [PMID: 33824498 PMCID: PMC8492766 DOI: 10.1038/s41435-021-00124-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 02/01/2023]
Abstract
The gastrointestinal tract harbors trillions of microbial species, collectively termed the microbiota, which establish a symbiotic relationship with the host. Decades of research have emphasized the necessity of microbial signals in the development, maturation, and function of host physiology. However, changes in the composition or containment of the microbiota have been linked to the development of several chronic inflammatory diseases, including inflammatory bowel diseases. Intestinal epithelial cells (IECs) are in constant contact with the microbiota and are critical for maintaining intestinal homeostasis. Signals from the microbiota are directly sensed by IECs and influence intestinal health by calibrating immune cell responses and fortifying intestinal barrier function. IECs detect commensal microbes through engagement of common pattern recognition receptors or by sensing the production of microbial-derived metabolites. Deficiencies in these microbial-detecting pathways in IECs leads to impaired epithelial barrier function and altered intestinal homeostasis. This Review aims to highlight the pathways by which IECs sense microbiota-derived signals and the necessity of these detection pathways in maintaining epithelial barrier integrity.
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Affiliation(s)
- Emily M Eshleman
- Division of Immunobiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Theresa Alenghat
- Division of Immunobiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
- Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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55
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Escherichia coli small molecule metabolism at the host-microorganism interface. Nat Chem Biol 2021; 17:1016-1026. [PMID: 34552219 DOI: 10.1038/s41589-021-00807-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 04/30/2021] [Indexed: 12/20/2022]
Abstract
Escherichia coli are a common component of the human microbiota, and isolates exhibit probiotic, commensal and pathogenic roles in the host. E. coli members often use diverse small molecule chemistry to regulate intrabacterial, intermicrobial and host-bacterial interactions. While E. coli are considered to be a well-studied model organism in biology, much of their chemical arsenal has only more recently been defined, and much remains to be explored. Here we describe chemical signaling systems in E. coli in the context of the broader field of metabolism at the host-bacteria interface and the role of this signaling in disease modulation.
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56
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Marszalek-Grabska M, Walczak K, Gawel K, Wicha-Komsta K, Wnorowska S, Wnorowski A, Turski WA. Kynurenine emerges from the shadows – Current knowledge on its fate and function. Pharmacol Ther 2021; 225:107845. [DOI: 10.1016/j.pharmthera.2021.107845] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022]
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Pernomian L, Duarte-Silva M, de Barros Cardoso CR. The Aryl Hydrocarbon Receptor (AHR) as a Potential Target for the Control of Intestinal Inflammation: Insights from an Immune and Bacteria Sensor Receptor. Clin Rev Allergy Immunol 2021; 59:382-390. [PMID: 32279195 DOI: 10.1007/s12016-020-08789-3] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The aryl hydrocarbon receptor (AHR) is widely expressed in immune and non-immune cells of the gut and its activation has been correlated to the outcome of inflammatory bowel diseases (IBD). In ulcerative colitis and Crohn's disease, there is an excessive chronic inflammation with massive accumulation of leukocytes in the gut, in an attempt to constrain the invasion of pathogenic microorganisms on the damaged organ. Accordingly, it is known that dietary components, xenobiotics, and some chemicals or metabolites can activate AHR and induce the modulation of inflammatory responses. In fact, the AHR triggering by specific ligands during inflammatory conditions results in decreased IFNγ, IL-6, IL-12, TNF, IL-7, and IL-17, along with reduced microbial translocation and fibrosis in the gut. Moreover, upon AHR activation, there are increased regulatory mechanisms such as IL-10, IL-22, prostaglandin E2, and Foxp3, besides the production of anti-microbial peptides and epithelial repair. Most interestingly, commensal bacteria or their metabolites may also activate this receptor, thus contributing to the restoration of gut normobiosis and homeostasis. In line with that, Lactobacillus reuteri, Lactobacillus bulgaricus, or microbial products such as tryptophan metabolites, indole-3-pyruvic acid, urolithin A, short-chain fatty acids, dihydroxyquinoline, and others may regulate the inflammation by mechanisms dependent on AHR activation. Hence, here we discussed the potential modulatory role of AHR on intestinal inflammation, focused on the reestablishment of homeostasis through the receptor triggering by microbial metabolites. Finally, the development of AHR-based therapies derived from bacteria products could represent an important future alternative for controlling IBD.
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Affiliation(s)
- Larissa Pernomian
- Department of Clinical Analysis, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Murillo Duarte-Silva
- Department of Biochemistry and Immunology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Cristina Ribeiro de Barros Cardoso
- Department of Clinical Analysis, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
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58
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Stockinger B, Shah K, Wincent E. AHR in the intestinal microenvironment: safeguarding barrier function. Nat Rev Gastroenterol Hepatol 2021; 18:559-570. [PMID: 33742166 PMCID: PMC7611426 DOI: 10.1038/s41575-021-00430-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/09/2021] [Indexed: 02/01/2023]
Abstract
Mammalian aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that belongs to the basic helix-loop-helix (bHLH)-PAS family of transcription factors, which are evolutionarily conserved environmental sensors. In the absence of ligands, AHR resides in the cytoplasm in a complex with molecular chaperones such as HSP90, XAP2 and p23. Upon ligand binding, AHR translocates into the nuclear compartment, where it dimerizes with its partner protein, AHR nuclear translocator (ARNT), an obligatory partner for the DNA-binding and functional activity. Historically, AHR had mostly been considered as a key intermediary for the detrimental effects of environmental pollutants on the body. However, following the discovery of AHR-mediated functions in various immune cells, as well as the emergence of non-toxic 'natural' AHR ligands, this view slowly began to change, and the study of AHR-deficient mice revealed a plethora of important beneficial functions linked to AHR activation. This Review focuses on regulation of the AHR pathway and the barrier-protective roles AHR has in haematopoietic, as well as non-haematopoietic, cells within the intestinal microenvironment. It covers the nature of AHR ligands and feedback regulation of the AHR pathway, outlining the currently known physiological functions in immune, epithelial, endothelial and neuronal cells of the intestine.
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Affiliation(s)
| | | | - Emma Wincent
- Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
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59
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Dowdell AS, Colgan SP. Metabolic Host-Microbiota Interactions in Autophagy and the Pathogenesis of Inflammatory Bowel Disease (IBD). Pharmaceuticals (Basel) 2021; 14:708. [PMID: 34451805 PMCID: PMC8399382 DOI: 10.3390/ph14080708] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 12/17/2022] Open
Abstract
Inflammatory bowel disease (IBD) is a family of conditions characterized by chronic, relapsing inflammation of the gastrointestinal tract. IBD afflicts over 3 million adults in the United States and shows increasing prevalence in the Westernized world. Current IBD treatments center on modulation of the damaging inflammatory response and carry risks such as immunosuppression, while the development of more effective treatments is hampered by our poor understanding of the molecular mechanisms of IBD pathogenesis. Previous genome-wide association studies (GWAS) have demonstrated that gene variants linked to the cellular response to microorganisms are most strongly associated with an increased risk of IBD. These studies are supported by mechanistic work demonstrating that IBD-associated polymorphisms compromise the intestine's anti-microbial defense. In this review, we summarize the current knowledge regarding IBD as a disease of defects in host-microbe interactions and discuss potential avenues for targeting this mechanism for future therapeutic development.
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Affiliation(s)
| | - Sean P. Colgan
- Department of Medicine and the Mucosal Inflammation Program, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA;
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60
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Ala M. Tryptophan metabolites modulate inflammatory bowel disease and colorectal cancer by affecting immune system. Int Rev Immunol 2021; 41:326-345. [PMID: 34289794 DOI: 10.1080/08830185.2021.1954638] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tryptophan is an essential amino acid, going through three different metabolic pathways in the intestines. Indole pathway in the gut microbiota, serotonin system in the enterochromaffin cells and kynurenine pathway in the immune cells and intestinal lining are the three arms of tryptophan metabolism in the intestines. Clinical, in vivo and in vitro studies showed that each one of these arms has a significant impact on IBD. This review explains how different metabolites of tryptophan are involved in the pathophysiology of IBD and colorectal cancer, as a major complication of IBD. Indole metabolites alleviate colitis and protect against colorectal cancer while serotonin arm follows a more complicated and receptor-specific pattern. Indole metabolites and kynurenine interact with aryl hydrocarbon receptor (AHR) to induce T regulatory cells differentiation, confine Th17 and Th1 response and produce anti-inflammatory mediators. Kynurenine decreases tumor-infiltrating CD8+ cells and mediates tumor cells immune evasion. Serotonin system also increases colorectal cancer cells proliferation and metastasis while, indole metabolites can profoundly decrease colorectal cancer growth. Targeted therapy for tryptophan metabolites may improve the management of IBD and colorectal cancer, e.g. supplementation of indole metabolites such as indole-3-carbinol (I3C), inhibition of kynurenine monooxygenase (KMO) and selective stimulation or inhibition of specific serotonergic receptors can mitigate colitis. Furthermore, it will be explained how indole metabolites supplementation, inhibition of indoleamine 2,3-dioxygenase 1 (IDO1), KMO and serotonin receptors can protect against colorectal cancer. Additionally, extensive molecular interactions between tryptophan metabolites and intracellular signaling pathways will be thoroughly discussed.
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Affiliation(s)
- Moein Ala
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
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61
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Jenkins BR, Blaseg NA, Grifka-Walk HM, Deuling B, Swain SD, Campbell EL, Walk ST, Kominsky DJ. Loss of interleukin-10 receptor disrupts intestinal epithelial cell proliferation and skews differentiation towards the goblet cell fate. FASEB J 2021; 35:e21551. [PMID: 34042222 DOI: 10.1096/fj.202002369r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 03/02/2021] [Accepted: 03/08/2021] [Indexed: 01/08/2023]
Abstract
Intestinal epithelial cells (IEC) are crucial for maintaining proper digestion and overall homeostasis of the gut mucosa. IEC proliferation and differentiation are tightly regulated by well described pathways, however, relatively little is known about how cytokines shape these processes. Given that the anti-inflammatory cytokine interleukin (IL)-10 promotes intestinal barrier function, and insufficient IL-10 signaling increases susceptibility to intestinal diseases like inflammatory bowel disease, we hypothesized that IL-10 signaling modulates processes underlying IEC proliferation and differentiation. This was tested using in vivo and in vitro IEC-specific IL-10 receptor 1 (IL-10R1) depletion under homeostatic conditions. Our findings revealed that loss of IL-10R1 drove lineage commitment toward a dominant goblet cell phenotype while decreasing absorptive cell-related features. Diminished IL-10 signaling also significantly elevated IEC proliferation with relatively minor changes to apoptosis. Characterization of signaling pathways upstream of proliferation demonstrated a significant reduction in the Wnt inhibitor, DKK1, increased nuclear localization of β-catenin, and increased transcripts of the proliferation marker, OLFM4, with IL-10R1 depletion. Phosphorylated STAT3 was nearly completely absent in IL-10R1 knockdown cells and may provide a mechanistic link between our observations and the regulation of these cellular processes. Our results demonstrate a novel role for IL-10 signaling in intestinal mucosal homeostasis by regulating proper balance of proliferation and IEC lineage fate.
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Affiliation(s)
- Brittany R Jenkins
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Nathan A Blaseg
- University of South Dakota Sanford School of Medicine, Sioux Falls, SD, USA
| | - Heather M Grifka-Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Benjamin Deuling
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Steve D Swain
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Eric L Campbell
- Centre for Experimental Medicine, Queens University Belfast, Belfast, Northern Ireland
| | - Seth T Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Douglas J Kominsky
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
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62
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Nguyen HD, Aljamaei HM, Stadnyk AW. The Production and Function of Endogenous Interleukin-10 in Intestinal Epithelial Cells and Gut Homeostasis. Cell Mol Gastroenterol Hepatol 2021; 12:1343-1352. [PMID: 34271223 PMCID: PMC8463866 DOI: 10.1016/j.jcmgh.2021.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 02/06/2023]
Abstract
The healthy gut is achieved and maintained through a balanced relationship between the mucosal immune system, microbial communities resident in the lumen, and the intestinal epithelium. The intestinal epithelium plays an exceptionally important role in harmonizing the interaction between the host immunity and the luminal residents, as this selectively permeable barrier separates but also allows interchange between the 2 environments. Interleukin (IL)-10 has been well established to play an important role in maintaining gut homeostasis by imparting diverse effects on a variety of cell types in this relationship. In the intestine, the source and the target of IL-10 include leukocytes and epithelial cells. Given that both the epithelium and IL-10 are essential players in supporting homeostasis, we discuss the relationship between these 2 factors, focusing on epithelial sources of IL-10 and the effects of IL-10 on the intestinal epithelium. Insight into this relationship reveals an important aspect of the innate immune function of intestinal epithelial cells.
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Affiliation(s)
- Huong D. Nguyen
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hanan M. Aljamaei
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Andrew W. Stadnyk
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada,Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada,Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada,Division of Gastroenterology & Nutrition, IWK Health Centre, Halifax, Nova Scotia, Canada,Correspondence Address correspondence to: Andrew W. Stadnyk, PhD, MIRA-lab, IWK Health Centre, 5850/5980 University Avenue, Halifax, Nova Scotia, Canada B3K 6R8. fax: (902) 470-7812.
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63
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Gwak MG, Chang SY. Gut-Brain Connection: Microbiome, Gut Barrier, and Environmental Sensors. Immune Netw 2021; 21:e20. [PMID: 34277110 PMCID: PMC8263213 DOI: 10.4110/in.2021.21.e20] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/09/2021] [Accepted: 06/12/2021] [Indexed: 02/08/2023] Open
Abstract
The gut is an important organ with digestive and immune regulatory function which consistently harbors microbiome ecosystem. The gut microbiome cooperates with the host to regulate the development and function of the immune, metabolic, and nervous systems. It can influence disease processes in the gut as well as extra-intestinal organs, including the brain. The gut closely connects with the central nervous system through dynamic bidirectional communication along the gut-brain axis. The connection between gut environment and brain may affect host mood and behaviors. Disruptions in microbial communities have been implicated in several neurological disorders. A link between the gut microbiota and the brain has long been described, but recent studies have started to reveal the underlying mechanism of the impact of the gut microbiota and gut barrier integrity on the brain and behavior. Here, we summarized the gut barrier environment and the 4 main gut-brain axis pathways. We focused on the important function of gut barrier on neurological diseases such as stress responses and ischemic stroke. Finally, we described the impact of representative environmental sensors generated by gut bacteria on acute neurological disease via the gut-brain axis.
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Affiliation(s)
- Min-Gyu Gwak
- Laboratory of Microbiology, College of Pharmacy, and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon 16499, Korea
| | - Sun-Young Chang
- Laboratory of Microbiology, College of Pharmacy, and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon 16499, Korea
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64
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Lin J, Sun-Waterhouse D, Cui C. The therapeutic potential of diet on immune-related diseases: based on the regulation on tryptophan metabolism. Crit Rev Food Sci Nutr 2021; 62:8793-8811. [PMID: 34085885 DOI: 10.1080/10408398.2021.1934813] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tryptophan (TRP), as an essential amino acid, plays crucial roles in maintaining immune homeostasis due to its complex metabolism pathway, including the microbial metabolism, 5-hydroxytryptamine and kynurenine pathways (KP). Metabolites from these pathways can act antioxidant and endogenous ligand of aryl hydrocarbon receptor (including microbiota metabolites: indole, indole aldehyde, indole acetic acid, indole acrylic acid, indole lactate, indole pyruvate acid, indole propionic acid, skatole, tryptamine, and indoxyl sulfate; and KP metabolites: kynurenine, kynurenic acid, 3-hydroxyanthranilic acid, xanthurenic acid, and cinnabarinic acid) for regulating immune response. In immune-related diseases, the production of pro-inflammatory cytokine activates indoleamine-2,3-dioxygenase, a rate-limiting enzyme of KP, leading to abnormal TRP metabolism in vivo. Many recent studies found that TRP metabolism could be regulated by diet, and the diet regulation on TRP metabolism could therapy related diseases. Accordingly, this review provides a critical overview of the relationships among diet, TRP metabolism and immunity with the aim to seek a treatment opportunity for immune-related diseases.
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Affiliation(s)
- Junjie Lin
- College of Food Science and Technology, South China University of Technology, Guangzhou, China
| | - Dongxiao Sun-Waterhouse
- College of Food Science and Technology, South China University of Technology, Guangzhou, China
| | - Chun Cui
- College of Food Science and Technology, South China University of Technology, Guangzhou, China.,Guangdong Wei-Wei Biotechnology Co., Ltd, Guangzhou, China
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65
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Grifka-Walk HM, Jenkins BR, Kominsky DJ. Amino Acid Trp: The Far Out Impacts of Host and Commensal Tryptophan Metabolism. Front Immunol 2021; 12:653208. [PMID: 34149693 PMCID: PMC8213022 DOI: 10.3389/fimmu.2021.653208] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Tryptophan (Trp) is an essential amino acid primarily derived from the diet for use by the host for protein synthesis. The intestinal tract is lined with cells, both host and microbial, that uptake and metabolize Trp to also generate important signaling molecules. Serotonin (5-HT), kynurenine and its downstream metabolites, and to a lesser extent other neurotransmitters are generated by the host to signal onto host receptors and elicit physiological effects. 5-HT production by neurons in the CNS regulates sleep, mood, and appetite; 5-HT production in the intestinal tract by enterochromaffin cells regulates gastric motility and inflammation in the periphery. Kynurenine can signal onto the aryl hydrocarbon receptor (AHR) to elicit pleiotropic responses from several cell types including epithelial and immune cells, or can be further metabolized into bioactive molecules to influence neurodegenerative disease. There is a remarkable amount of cross-talk with the microbiome with regard to tryptophan metabolites as well. The gut microbiome can regulate the production of host tryptophan metabolites and can use dietary or recycled trp to generate bioactive metabolites themselves. Trp derivatives like indole are able to signal onto xenobiotic receptors, including AHR, to elicit tolerogenic effects. Here, we review studies that demonstrate that tryptophan represents a key intra-kingdom signaling molecule.
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Affiliation(s)
| | | | - Douglas J. Kominsky
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
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66
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The role of mucosal barriers in human gut health. Arch Pharm Res 2021; 44:325-341. [PMID: 33890250 DOI: 10.1007/s12272-021-01327-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/26/2021] [Indexed: 12/15/2022]
Abstract
The intestinal mucosa is continuously exposed to a large number of commensal or pathogenic microbiota and foreign food antigens. The intestinal epithelium forms a dynamic physicochemical barrier to maintain immune homeostasis. To efficiently absorb nutrients from food, the epithelium in the small intestine has thin, permeable layers spread over a vast surface area. Epithelial cells are renewed from the crypt toward the villi, accompanying epithelial cell death and shedding, to control bacterial colonization. Tight junction and adherens junction proteins provide epithelial cell-cell integrity. Microbial signals are recognized by epithelial cells via toll-like receptors. Environmental signals from short-chain fatty acids derived from commensal microbiota metabolites, aryl hydrocarbon receptors, and hypoxia-induced factors fortify gut barrier function. Here we summarize recent findings regarding various environmental factors for gut barrier function. Further, we discuss the role of gut barriers in the pathogenesis of human intestinal disease and the challenges of therapeutic strategies targeting gut barrier restoration.
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67
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Levi I, Gurevich M, Perlman G, Magalashvili D, Menascu S, Bar N, Godneva A, Zahavi L, Chermon D, Kosower N, Wolf BC, Malka G, Lotan-Pompan M, Weinberger A, Yirmiya E, Rothschild D, Leviatan S, Tsur A, Didkin M, Dreyer S, Eizikovitz H, Titngi Y, Mayost S, Sonis P, Dolev M, Stern Y, Achiron A, Segal E. Potential role of indolelactate and butyrate in multiple sclerosis revealed by integrated microbiome-metabolome analysis. Cell Rep Med 2021; 2:100246. [PMID: 33948576 PMCID: PMC8080254 DOI: 10.1016/j.xcrm.2021.100246] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/18/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022]
Abstract
Multiple sclerosis (MS) is an immune-mediated disease whose precise etiology is unknown. Several studies found alterations in the microbiome of individuals with MS, but the mechanism by which it may affect MS is poorly understood. Here we analyze the microbiome of 129 individuals with MS and find that they harbor distinct microbial patterns compared with controls. To study the functional consequences of these differences, we measure levels of 1,251 serum metabolites in a subgroup of subjects and unravel a distinct metabolite signature that separates affected individuals from controls nearly perfectly (AUC = 0.97). Individuals with MS are found to be depleted in butyrate-producing bacteria and in bacteria that produce indolelactate, an intermediate in generation of the potent neuroprotective antioxidant indolepropionate, which we found to be lower in their serum. We identify microbial and metabolite candidates that may contribute to MS and should be explored further for their causal role and therapeutic potential.
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Affiliation(s)
- Izhak Levi
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michael Gurevich
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Gal Perlman
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - David Magalashvili
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Shay Menascu
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Noam Bar
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Anastasia Godneva
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Liron Zahavi
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Danyel Chermon
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Noa Kosower
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Bat Chen Wolf
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Gal Malka
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Maya Lotan-Pompan
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Adina Weinberger
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Erez Yirmiya
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Daphna Rothschild
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sigal Leviatan
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Avishag Tsur
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Maria Didkin
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Sapir Dreyer
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Hen Eizikovitz
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Yamit Titngi
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Sue Mayost
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Polina Sonis
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Mark Dolev
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Yael Stern
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
| | - Anat Achiron
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer, Ramat-Gan 526200, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Eran Segal
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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CD101 as an indicator molecule for pathological changes at the interface of host-microbiota interactions. Int J Med Microbiol 2021; 311:151497. [PMID: 33773220 DOI: 10.1016/j.ijmm.2021.151497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/22/2021] [Accepted: 03/16/2021] [Indexed: 11/21/2022] Open
Abstract
Intestinal microbiota signal to local and distant tissues in the body. Thus, they also regulate biochemical, metabolic and immunological processes in the gut and in the pancreas. Vice versa, eating habits or the immune system of the host shape the intraluminal microbiota. Disruptions of these versatile host-microbiota interactions underlie the pathogenesis of complex immune-mediated disorders such as inflammatory bowel disease (IBD) or type 1 diabetes (T1D). Consequently, dysbiosis and increased intestinal permeability associated with both disorders change the biology of underlying tissues, as evidenced, for example, by an altered expression of surface markers such as CD101 on immune cells located at these dynamic host-microbiota interfaces. CD101, a heavily glycosylated member of the immunoglobulin superfamiliy, is predominantly detected on myeloid cells, intraepithelial lymphocytes (IELs) and regulatory T cells (Tregs) in the gut. The expression of CD101 on both myeloid cells and T lymphocytes protects from experimental enterocolitis and T1D. The improved outcome of both diseases is associated with an anti-inflammatory cytokine profile and a reduced expansion of T cells. However, distinct bacteria suppress the expression of CD101 on myeloid cells, similar as does inflammation on T cells. Thus, the reduced CD101 expression in T1D and IBD patients might be a consequence of an altered composition of the intestinal microbiota, enhanced bacterial translocation and a subsequent primining of local and systemic inflammatory immune responses.
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Wu L, Tang Z, Chen H, Ren Z, Ding Q, Liang K, Sun Z. Mutual interaction between gut microbiota and protein/amino acid metabolism for host mucosal immunity and health. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2021; 7:11-16. [PMID: 33997326 PMCID: PMC8110859 DOI: 10.1016/j.aninu.2020.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/25/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023]
Abstract
In recent years, many studies have shown that the intestinal microflora has various effects that are linked to the critical physiological functions and pathological systems of the host. The intestinal microbial community is widely involved in the metabolism of food components such as protein, which is one of the essential nutrients in diets. Additionally, dietary protein/amino acids have been shown to have had a profound impact on profile and operation of gut microbiota. This review summarizes the current literature on the mutual interaction between intestinal microbiota and protein/amino acid metabolism for host mucosal immunity and health.
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Affiliation(s)
- Liuting Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
| | - Zhiru Tang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
| | - Huiyuan Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
| | - Zhongxiang Ren
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
| | - Qi Ding
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
| | - Kaiyang Liang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
| | - Zhihong Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715, China
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70
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Barroso A, Mahler JV, Fonseca-Castro PH, Quintana FJ. The aryl hydrocarbon receptor and the gut-brain axis. Cell Mol Immunol 2021; 18:259-268. [PMID: 33408340 PMCID: PMC8027889 DOI: 10.1038/s41423-020-00585-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/29/2020] [Indexed: 12/11/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor initially identified as the receptor for dioxin. Almost half a century after its discovery, AHR is now recognized as a receptor for multiple physiological ligands, with important roles in health and disease. In this review, we discuss the role of AHR in the gut-brain axis and its potential value as a therapeutic target for immune-mediated diseases.
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Affiliation(s)
- Andreia Barroso
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - João Vitor Mahler
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Pedro Henrique Fonseca-Castro
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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71
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Gu BH, Kim M, Yun CH. Regulation of Gastrointestinal Immunity by Metabolites. Nutrients 2021; 13:nu13010167. [PMID: 33430497 PMCID: PMC7826526 DOI: 10.3390/nu13010167] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
The gastrointestinal tract contains multiple types of immune cells that maintain the balance between tolerance and activation at the first line of host defense facing non-self antigens, including dietary antigens, commensal bacteria, and sometimes unexpected pathogens. The maintenance of homeostasis at the gastrointestinal tract requires stringent regulation of immune responses against various environmental conditions. Dietary components can be converted into gut metabolites with unique functional activities through host as well as microbial enzymatic activities. Accumulating evidence demonstrates that gastrointestinal metabolites have significant impacts on the regulation of intestinal immunity and are further integrated into the immune response of distal mucosal tissue. Metabolites, especially those derived from the microbiota, regulate immune cell functions in various ways, including the recognition and activation of cell surface receptors, the control of gene expression by epigenetic regulation, and the integration of cellular metabolism. These mucosal immune regulations are key to understanding the mechanisms underlying the development of gastrointestinal disorders. Here, we review recent advancements in our understanding of the role of gut metabolites in the regulation of gastrointestinal immunity, highlighting the cellular and molecular regulatory mechanisms by macronutrient-derived metabolites.
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Affiliation(s)
- Bon-Hee Gu
- Life and Industry Convergence Research Institute, Pusan National University, Miryang 50463, Korea;
| | - Myunghoo Kim
- Life and Industry Convergence Research Institute, Pusan National University, Miryang 50463, Korea;
- Department of Animal Science, College of Natural Resources & Life Science, Pusan National University, Miryang 50463, Korea
- Correspondence: (M.K.); (C.-H.Y.)
| | - Cheol-Heui Yun
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul 08826, Korea
- Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do 25354, Korea
- Correspondence: (M.K.); (C.-H.Y.)
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72
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Pothuraju R, Chaudhary S, Rachagani S, Kaur S, Roy HK, Bouvet M, Batra SK. Mucins, gut microbiota, and postbiotics role in colorectal cancer. Gut Microbes 2021; 13:1974795. [PMID: 34586012 PMCID: PMC8489937 DOI: 10.1080/19490976.2021.1974795] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/14/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023] Open
Abstract
An imbalance in the crosstalk between the host and gut microbiota affects the intestinal barrier function, which results in inflammatory diseases and colorectal cancer. The colon epithelium protects itself from a harsh environment and various pathogenic organisms by forming a double mucus layer, primarily comprising mucins. Recent studies are focusing on how dietary patterns alter the gut microbiota composition, which in turn regulates mucin expression and maintains the intestinal layers. In addition, modulation of gut microbiota by microbiotic therapy (involving fecal microbiota transplantation) has emerged as a significant factor in the pathologies associated with dysbiosis. Therefore, proper communication between host and gut microbiota via different dietary patterns (prebiotics and probiotics) is needed to maintain mucus composition, mucin synthesis, and regulation. Here, we review how the interactions between diet and gut microbiota and bacterial metabolites (postbiotics) regulate mucus layer functionalities and mucin expression in human health and disease.
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Affiliation(s)
- Ramesh Pothuraju
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sanjib Chaudhary
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Satyanarayana Rachagani
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sukhwinder Kaur
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Hemant K. Roy
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Michael Bouvet
- Division of Surgical Oncology, Department of Surgery, University of California San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, San Diego, CA, USA
| | - Surinder K. Batra
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
- Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
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Wang RX, Henen MA, Lee JS, Vögeli B, Colgan SP. Microbiota-derived butyrate is an endogenous HIF prolyl hydroxylase inhibitor. Gut Microbes 2021; 13:1938380. [PMID: 34190032 PMCID: PMC8253137 DOI: 10.1080/19490976.2021.1938380] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 05/27/2021] [Indexed: 02/04/2023] Open
Abstract
The gut microbiota is essential for human health. Microbial supply of short-chain fatty acids (SCFAs), particularly butyrate, is a well-established contributor to gut homeostasis and disease resistance. Reaching millimolar luminal concentrations, butyrate is sequestered and utilized in the colon as the favored energy source for intestinal epithelia. Given the steep oxygen gradient across the anoxic lumen and the highly oxygenated lamina propria, the colon provides a particularly interesting environment to study oxygen sensing. Previous studies have shown that the transcription factor hypoxia-inducible factor (HIF) is stabilized in healthy colonic epithelia. Here we show that butyrate directly inhibits HIF prolyl hydroxylases (PHDs) to stabilize HIF. We find that butyrate stabilizes HIF in vitro despite eliminating β-oxidation and resultant oxygen consumption. Using recombinant PHD protein in combination with nuclear magnetic resonance and enzymatic biochemical assays, we identify butyrate to bind and function as a unique, noncompetitive inhibitor of PHDs relative to other SCFAs. Butyrate inhibited PHD with a noncompetitive Ki of 5.3 ± 0.5 mM, a physiologically relevant concentration. We also confirm that microbiota-derived butyrate is necessary to stabilize HIF in mice colonic tissue through antibiotic-induced butyrate depletion and reconstitution experiments. Our results suggest that the co-evolution of mammals and mutualistic microbiota has selected for butyrate to impact a critical gene regulation pathway that can be extended beyond the mammalian gut. As PHDs are a major target for drug development in the stabilization of HIF, butyrate holds great potential as a well-tolerated endogenous inhibitor with far-reaching therapeutic impact.
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Affiliation(s)
- Ruth X. Wang
- Department of Medicine, Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- School of Medicine, Medical Scientist Training Program, University of Colorado, Aurora, CO, USA
| | - Morkos A. Henen
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmaceutical Organic Chemistry, Mansoura University, Mansoura, Egypt
| | - J. Scott Lee
- Department of Medicine, Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Beat Vögeli
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sean P. Colgan
- Department of Medicine, Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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74
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Transcriptional programmes underlying cellular identity and microbial responsiveness in the intestinal epithelium. Nat Rev Gastroenterol Hepatol 2021; 18:7-23. [PMID: 33024279 PMCID: PMC7997278 DOI: 10.1038/s41575-020-00357-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/12/2020] [Indexed: 12/19/2022]
Abstract
The intestinal epithelium serves the unique and critical function of harvesting dietary nutrients, while simultaneously acting as a cellular barrier separating tissues from the luminal environment and gut microbial ecosystem. Two salient features of the intestinal epithelium enable it to perform these complex functions. First, cells within the intestinal epithelium achieve a wide range of specialized identities, including different cell types and distinct anterior-posterior patterning along the intestine. Second, intestinal epithelial cells are sensitive and responsive to the dynamic milieu of dietary nutrients, xenobiotics and microorganisms encountered in the intestinal luminal environment. These diverse identities and responsiveness of intestinal epithelial cells are achieved in part through the differential transcription of genes encoded in their shared genome. Here, we review insights from mice and other vertebrate models into the transcriptional regulatory mechanisms underlying intestinal epithelial identity and microbial responsiveness, including DNA methylation, chromatin accessibility, histone modifications and transcription factors. These studies are revealing that most transcription factors involved in intestinal epithelial identity also respond to changes in the microbiota, raising both opportunities and challenges to discern the underlying integrative transcriptional regulatory networks.
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75
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Yan X, Yan J, Xiang Q, Wang F, Dai H, Huang K, Fang L, Yao H, Wang L, Zhang W. Fructooligosaccharides protect against OVA-induced food allergy in mice by regulating the Th17/Treg cell balance using tryptophan metabolites. Food Funct 2021; 12:3191-3205. [PMID: 33735338 DOI: 10.1039/d0fo03371e] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Fructooligosaccharides (FOS) can change gut microbiota composition and play a protective role in food allergy (FA).
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Affiliation(s)
- Xiumei Yan
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Jingbin Yan
- Department of Ultrasonography
- Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine
- Wenzhou 325000
- China
| | - Qiangwei Xiang
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Fanyan Wang
- Department of Pathophysiology
- School of Basic Medical Sciences
- Wenzhou Medical University
- Wenzhou 325000
- China
| | - Huan Dai
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Kaiyu Huang
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Lingjuan Fang
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Hao Yao
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Lingya Wang
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
| | - Weixi Zhang
- Department of Pediatrics
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
- Wenzhou 325000
- China
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Ehrlich AM, Pacheco AR, Henrick BM, Taft D, Xu G, Huda MN, Mishchuk D, Goodson ML, Slupsky C, Barile D, Lebrilla CB, Stephensen CB, Mills DA, Raybould HE. Indole-3-lactic acid associated with Bifidobacterium-dominated microbiota significantly decreases inflammation in intestinal epithelial cells. BMC Microbiol 2020; 20:357. [PMID: 33225894 PMCID: PMC7681996 DOI: 10.1186/s12866-020-02023-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
Background Bifidobacterium longum subsp. infantis (B. infantis) is a commensal bacterium that colonizes the gastrointestinal tract of breast-fed infants. B. infantis can efficiently utilize the abundant supply of oligosaccharides found in human milk (HMO) to help establish residence. We hypothesized that metabolites from B. infantis grown on HMO produce a beneficial effect on the host. Results In a previous study, we demonstrated that B. infantis routinely dominated the fecal microbiota of a breast fed Bangladeshi infant cohort (1). Characterization of the fecal metabolome of binned samples representing high and low B. infantis populations from this cohort revealed higher amounts of the tryptophan metabolite indole-3-lactic acid (ILA) in feces with high levels of B. infantis. Further in vitro analysis confirmed that B. infantis produced significantly greater quantities of the ILA when grown on HMO versus lactose, suggesting a growth substrate relationship to ILA production. The direct effects of ILA were assessed in a macrophage cell line and intestinal epithelial cell lines. ILA (1-10 mM) significantly attenuated lipopolysaccharide (LPS)-induced activation of NF-kB in macrophages. ILA significantly attenuated TNF-α- and LPS-induced increase in the pro-inflammatory cytokine IL-8 in intestinal epithelial cells. ILA increased mRNA expression of the aryl hydrogen receptor (AhR)-target gene CYP1A1 and nuclear factor erythroid 2–related factor 2 (Nrf2)-targeted genes glutathione reductase 2 (GPX2), superoxide dismutase 2 (SOD2), and NAD(P) H dehydrogenase (NQO1). Pretreatment with either the AhR antagonist or Nrf-2 antagonist inhibited the response of ILA on downstream effectors. Conclusions These findings suggest that ILA, a predominant metabolite from B. infantis grown on HMO and elevated in infant stool high in B. infantis, and protects gut epithelial cells in culture via activation of the AhR and Nrf2 pathway. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-020-02023-y.
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Affiliation(s)
- Amy M Ehrlich
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Alline R Pacheco
- Foods for Health Institute, University of California, Davis, CA, USA.,Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Bethany M Henrick
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.,Foods for Health Institute, University of California, Davis, CA, USA.,Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Diana Taft
- Foods for Health Institute, University of California, Davis, CA, USA.,Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Gege Xu
- Department of Chemistry, University of California, Davis, CA, USA
| | - M Nazmul Huda
- Enteric and Respiratory Infections Unit, Infectious Diseases Division, icddr,b, Dhaka, Bangladesh.,US Department of Agriculture, Western Human Nutrition Research Center, Davis, CA, USA
| | - Darya Mishchuk
- Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Michael L Goodson
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Carolyn Slupsky
- Department of Food Science and Technology, University of CA, Davis, CA, USA.,Department of Nutrition, University of California, Davis, CA, USA
| | - Daniela Barile
- Foods for Health Institute, University of California, Davis, CA, USA.,Department of Food Science and Technology, University of CA, Davis, CA, USA
| | | | - Charles B Stephensen
- US Department of Agriculture, Western Human Nutrition Research Center, Davis, CA, USA.,Department of Nutrition, University of California, Davis, CA, USA
| | - David A Mills
- Foods for Health Institute, University of California, Davis, CA, USA.,Department of Food Science and Technology, University of CA, Davis, CA, USA
| | - Helen E Raybould
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
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77
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Zhang J, Zhu S, Ma N, Johnston LJ, Wu C, Ma X. Metabolites of microbiota response to tryptophan and intestinal mucosal immunity: A therapeutic target to control intestinal inflammation. Med Res Rev 2020; 41:1061-1088. [PMID: 33174230 DOI: 10.1002/med.21752] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/12/2020] [Accepted: 10/28/2020] [Indexed: 12/13/2022]
Abstract
In a complex, diverse intestinal environment, commensal microbiota metabolizes excessive dietary tryptophan to produce more bioactive metabolites connecting with kinds of diverse process, such as host physiological defense, homeostasis, excessive immune activation and the progression and outcome of different diseases, such as inflammatory bowel disease, irritable bowel syndrome and others. Although commensal microbiota includes bacteria, fungi, and protozoa and all that, they often have the similar metabolites in tryptophan metabolism process via same or different pathways. These metabolites can work as signal to activate the innate immunity of intestinal mucosa and induce the rapid inflammation response. They are critical in reconstruction of lumen homeostasis as well. This review aims to seek the potential function and mechanism of microbiota-derived tryptophan metabolites as targets to regulate and shape intestinal immune function, which mainly focused on two aspects. First, analyze the character of tryptophan metabolism in bacteria, fungi, and protozoa, and assess the functions of their metabolites (including indole and eight other derivatives, serotonin (5-HT) and d-tryptophan) on regulating the integrity of intestinal epithelium and the immunity of the intestinal mucosa. Second, focus on the mediator and pathway for their recognition, transfer and crosstalk between microbiota-derived tryptophan metabolites and intestinal mucosal immunity. Disruption of intestinal homeostasis has been described in different intestinal inflammatory diseases, available data suggest the remarkable potential of tryptophan-derived aryl hydrocarbon receptor agonists, indole derivatives on lumen equilibrium. These metabolites as preventive and therapeutic interventions have potential to promote proinflammatory or anti-inflammatory responses of the gut.
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Affiliation(s)
- Jie Zhang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.,Animal Husbandry and Veterinary Department, Beijing Vocational College of Agriculture, Beijing, China
| | - Shengwei Zhu
- Institute of Botany, Key laboratory of plant molecular physiology, Chinese Academy of Sciences, Beijing, China
| | - Ning Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Lee J Johnston
- West Central Research and Outreach Center, University of Minnesota, Morris, Minnesota, USA
| | - Chaodong Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas, USA
| | - Xi Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
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78
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Fay NC, Muthusamy BP, Nyugen LP, Desai RC, Taverner A, MacKay J, Seung M, Hunter T, Liu K, Chandalia A, Coyle MP, Kim HL, Postlethwaite S, Mangat K, Song L, Seto E, Alam A, Olson CV, Feng W, Saberi M, Mahmood TA, Mrsny RJ. A Novel Fusion of IL-10 Engineered to Traffic across Intestinal Epithelium to Treat Colitis. THE JOURNAL OF IMMUNOLOGY 2020; 205:3191-3204. [PMID: 33148717 DOI: 10.4049/jimmunol.2000848] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/03/2020] [Indexed: 01/08/2023]
Abstract
IL-10 is a potent anti-inflammatory cytokine capable of suppressing a number of proinflammatory signals associated with intestinal inflammatory diseases, such as ulcerative colitis and Crohn's disease. Clinical use of human IL-10 (hIL-10) has been limited by anemia and thrombocytopenia following systemic injection, side effects that might be eliminated by a gut-restricted distribution. We have identified a transcytosis pathway used by cholix, an exotoxin secreted by nonpandemic forms of the intestinal pathogen Vibrio cholerae A nontoxic fragment of the first 386 aa of cholix was genetically fused to hIL-10 to produce recombinant AMT-101. In vitro and in vivo characterization of AMT-101 showed it to efficiently cross healthy human intestinal epithelium (SMI-100) by a vesicular transcytosis process, activate hIL-10 receptors in an engineered U2OS osteosarcoma cell line, and increase cellular phospho-STAT3 levels in J774.2 mouse macrophage cells. AMT-101 was taken up by inflamed intestinal mucosa and activated pSTAT3 in the lamina propria with limited systemic distribution. AMT-101 administered to healthy mice by oral gavage or to cynomolgus monkeys (nonhuman primates) by colonic spray increased circulating levels of IL-1R antagonist (IL-1Ra). Oral gavage of AMT-101 in two mouse models of induced colitis prevented associated pathological events and plasma cytokine changes. Overall, these studies suggest that AMT-101 can efficiently overcome the epithelial barrier to focus biologically active IL-10 to the intestinal lamina propria.
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Affiliation(s)
- Nicole C Fay
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | | | - Linh P Nyugen
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Radhika C Desai
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Alistair Taverner
- Department of Pharmacy and Pharmacology, University of Bath, BA2 7AY Bath, United Kingdom
| | - Julia MacKay
- Department of Pharmacy and Pharmacology, University of Bath, BA2 7AY Bath, United Kingdom
| | - Minji Seung
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Tom Hunter
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Keyi Liu
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | | | - Michael P Coyle
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Hyojin L Kim
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | | | | | - Lisa Song
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Elbert Seto
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Aatif Alam
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Charles V Olson
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Weijun Feng
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Maziyar Saberi
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Tahir A Mahmood
- Applied Molecular Transport, South San Francisco, CA 94080; and
| | - Randall J Mrsny
- Applied Molecular Transport, South San Francisco, CA 94080; and .,Department of Pharmacy and Pharmacology, University of Bath, BA2 7AY Bath, United Kingdom
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79
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Nutritional Therapy to Modulate Tryptophan Metabolism and Aryl Hydrocarbon-Receptor Signaling Activation in Human Diseases. Nutrients 2020; 12:nu12092846. [PMID: 32957545 PMCID: PMC7551725 DOI: 10.3390/nu12092846] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/10/2020] [Accepted: 09/12/2020] [Indexed: 02/07/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a nuclear protein which, upon association with certain endogenous and exogenous ligands, translocates into the nucleus, binds DNA and regulates gene expression. Tryptophan (Trp) metabolites are one of the most important endogenous AhR ligands. The intestinal microbiota is a critical player in human intestinal homeostasis. Many of its effects are mediated by an assembly of metabolites, including Trp metabolites. In the intestine, Trp is metabolized by three main routes, leading to kynurenine, serotonin, and indole derivative synthesis under the direct or indirect involvement of the microbiota. Disturbance in Trp metabolism and/or AhR activation is strongly associated with multiple gastrointestinal, neurological and metabolic disorders, suggesting Trp metabolites/AhR signaling modulation as an interesting therapeutic perspective. In this review, we describe the most recent advances concerning Trp metabolism and AhR signaling in human health and disease, with a focus on nutrition as a potential therapy to modulate Trp metabolites acting on AhR. A better understanding of the complex balance between these pathways in human health and disease will yield therapeutic opportunities.
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80
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The Effects of Dietary Glycine on the Acetic Acid-Induced Mouse Model of Colitis. Mediators Inflamm 2020; 2020:5867627. [PMID: 32831636 PMCID: PMC7426780 DOI: 10.1155/2020/5867627] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/03/2020] [Accepted: 07/09/2020] [Indexed: 12/15/2022] Open
Abstract
Inflammatory bowel disease, a gut disease that is prevalent worldwide, is characterized by chronic intestinal inflammation, such as colitis, and disorder of the gut microbiome. Glycine (Gly) is the simplest amino acid and functions as an anti-inflammatory immune-nutrient and intestinal microbiota regulator. This study aimed at investigating the effect of Gly on colitis induced in mice by intrarectal administration of 5% acetic acid (AA). Bodyweight and survival rates were monitored, and colonic length and weight, serum amino acid concentrations, intestinal inflammation-related gene expression, and colonic microbiota abundances were analyzed. The results showed that Gly dietary supplementation had no effect on the survival rate or the ratio of colonic length to weight. However, Gly supplementation reversed the AA-induced increase in serum concentrations of amino acids such as glutamate, leucine, isoleucine, and valine. Furthermore, Gly inhibited colonic gene expression of interleukin- (IL-) 1β and promoted IL-10 expression in colitis mice. Gly supplementation also reversed the AA-induced reduction in the abundance of bacteria such as Clostridia, Ruminococcaceae, and Clostridiales. This change in the intestinal microbiota was possibly attributable to the changes in colonic IL-10 expression and serum concentrations of valine and leucine. In sum, Gly supplementation regulated the serum concentrations of amino acids, the levels of colonic immune-associated gene expression, and the intestinal microbiota in a mouse model of colitis. These findings enhance our understanding of the role of Gly in regulating metabolism, intestinal immunity, and the gut microbiota in animals afflicted with colitis.
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81
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Microbial tryptophan metabolites regulate gut barrier function via the aryl hydrocarbon receptor. Proc Natl Acad Sci U S A 2020; 117:19376-19387. [PMID: 32719140 DOI: 10.1073/pnas.2000047117] [Citation(s) in RCA: 292] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are associated with dysbiosis of the gut microbiome. Emerging evidence suggests that small-molecule metabolites derived from bacterial breakdown of a variety of dietary nutrients confer a wide array of host benefits, including amelioration of inflammation in IBDs. Yet, in many cases, the molecular pathways targeted by these molecules remain unknown. Here, we describe roles for three metabolites-indole-3-ethanol, indole-3-pyruvate, and indole-3-aldehyde-which are derived from gut bacterial metabolism of the essential amino acid tryptophan, in regulating intestinal barrier function. We determined that these metabolites protect against increased gut permeability associated with a mouse model of colitis by maintaining the integrity of the apical junctional complex and its associated actin regulatory proteins, including myosin IIA and ezrin, and that these effects are dependent on the aryl hydrocarbon receptor. Our studies provide a deeper understanding of how gut microbial metabolites affect host defense mechanisms and identify candidate pathways for prophylactic and therapeutic treatments for IBDs.
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82
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Saraiva M, Vieira P, O'Garra A. Biology and therapeutic potential of interleukin-10. J Exp Med 2020; 217:jem.20190418. [PMID: 31611251 PMCID: PMC7037253 DOI: 10.1084/jem.20190418] [Citation(s) in RCA: 427] [Impact Index Per Article: 106.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/05/2019] [Accepted: 09/11/2019] [Indexed: 12/13/2022] Open
Abstract
The authors review the molecular mechanisms regulating IL-10 production and response and describe classic and novel functions of IL-10 in immune and non-immune cells. They further discuss the therapeutic potential of IL-10 in different diseases and the outstanding questions underlying an effective application of IL-10 in clinical settings. The cytokine IL-10 is a key anti-inflammatory mediator ensuring protection of a host from over-exuberant responses to pathogens and microbiota, while playing important roles in other settings as sterile wound healing, autoimmunity, cancer, and homeostasis. Here we discuss our current understanding of the regulation of IL-10 production and of the molecular pathways associated with IL-10 responses. In addition to IL-10’s classic inhibitory effects on myeloid cells, we also describe the nonclassic roles attributed to this pleiotropic cytokine, including how IL-10 regulates basic processes of neural and adipose cells and how it promotes CD8 T cell activation, as well as epithelial repair. We further discuss its therapeutic potential in the context of different diseases and the outstanding questions that may help develop an effective application of IL-10 in diverse clinical settings.
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Affiliation(s)
- Margarida Saraiva
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Paulo Vieira
- Department of Immunology, Unité Lymphopoièse, Institut Pasteur, Paris, France.,University Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France.,Institut National de la Santé et de la Recherche Médicale U1223, Paris, France
| | - Anne O'Garra
- Laboratory of Immunoregulation and Infection, The Francis Crick Institute, London, UK.,National Heart and Lung Institute, Imperial College London, UK
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83
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Puccetti M, Xiroudaki S, Ricci M, Giovagnoli S. Postbiotic-Enabled Targeting of the Host-Microbiota-Pathogen Interface: Hints of Antibiotic Decline? Pharmaceutics 2020; 12:E624. [PMID: 32635461 PMCID: PMC7408102 DOI: 10.3390/pharmaceutics12070624] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/24/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
Mismanagement of bacterial infection therapies has undermined the reliability and efficacy of antibiotic treatments, producing a profound crisis of the antibiotic drug market. It is by now clear that tackling deadly infections demands novel strategies not only based on the mere toxicity of anti-infective compounds. Host-directed therapies have been the first example as novel treatments with alternate success. Nevertheless, recent advances in the human microbiome research have provided evidence that compounds produced by the microbial metabolism, namely postbiotics, can have significant impact on human health. Such compounds target the host-microbe-pathogen interface rescuing biotic and immune unbalances as well as inflammation, thus providing novel therapeutic opportunities. This work discusses critically, through literature review and personal contributions, these novel nonantibiotic treatment strategies for infectious disease management and resistance prevention, which could represent a paradigm change rocking the foundation of current antibiotic therapy tenets.
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Affiliation(s)
| | | | | | - Stefano Giovagnoli
- Department of Pharmaceutical Sciences, via del Liceo 1, University of Perugia, 06123 Perugia, Italy; (M.P.); (S.X.); (M.R.)
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84
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Tryptophan Metabolism, Regulatory T Cells, and Inflammatory Bowel Disease: A Mini Review. Mediators Inflamm 2020; 2020:9706140. [PMID: 32617076 PMCID: PMC7306093 DOI: 10.1155/2020/9706140] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 05/26/2020] [Indexed: 02/06/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract resulting from the homeostasis imbalance of intestinal microenvironment, immune dysfunction, environmental and genetic factors, and so on. This disease is associated with multiple immune cells including regulatory T cells (Tregs). Tregs are a subset of T cells regulating the function of various immune cells to induce immune tolerance and maintain intestinal immune homeostasis. Tregs are correlated with the initiation and progression of IBD; therefore, strategies that affect the differentiation and function of Tregs may be promising for the prevention of IBD-associated pathology. It is worth noting that tryptophan (Trp) metabolism is effective in inducing the differentiation of Tregs through microbiota-mediated degradation and kynurenine pathway (KP), which is important for maintaining the function of Tregs. Interestingly, patients with IBD show Trp metabolism disorder in the pathological process, including changes in the concentrations of Trp and its metabolites and alteration in the activities of related catalytic enzymes. Thus, manipulation of Treg differentiation through Trp metabolism may provide a potential target for prevention of IBD. The purpose of this review is to highlight the relationship between Trp metabolism and Treg differentiation and the role of this interaction in the pathogenesis of IBD.
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85
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ROS-associated immune response and metabolism: a mechanistic approach with implication of various diseases. Arch Toxicol 2020; 94:2293-2317. [PMID: 32524152 DOI: 10.1007/s00204-020-02801-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 06/02/2020] [Indexed: 12/14/2022]
Abstract
The immune system plays a pivotal role in maintaining the defense mechanism against external agents and also internal danger signals. Metabolic programming of immune cells is required for functioning of different subsets of immune cells under different physiological conditions. The field of immunometabolism has gained ground because of its immense importance in coordination and balance of immune responses. Metabolism is very much related with production of energy and certain by-products. Reactive oxygen species (ROS) are generated as one of the by-products of various metabolic pathways. The amount, localization of ROS and redox status determine transcription of genes, and also influences the metabolism of immune cells. This review discusses ROS, metabolism of immune cells at different cellular conditions and sheds some light on how ROS might regulate immunometabolism.
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86
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Golonka RM, Xiao X, Abokor AA, Joe B, Vijay-Kumar M. Altered nutrient status reprograms host inflammation and metabolic health via gut microbiota. J Nutr Biochem 2020; 80:108360. [PMID: 32163821 PMCID: PMC7242157 DOI: 10.1016/j.jnutbio.2020.108360] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/07/2020] [Accepted: 02/08/2020] [Indexed: 02/07/2023]
Abstract
The metabolism of macro- and micronutrients is a complex and highly regulated biological process. An imbalance in the metabolites and their signaling networks can lead to nonresolving inflammation and consequently to the development of chronic inflammatory-associated diseases. Therefore, identifying the accumulated metabolites and altered pathways during inflammatory disorders would not only serve as "real-time" markers but also help in the development of nutritional therapeutics. In this review, we explore recent research that has delved into elucidating the effects of carbohydrate/calorie restriction, protein malnutrition, lipid emulsions and micronutrient deficiencies on metabolic health and inflammation. Moreover, we describe the integrated stress response in terms of amino acid starvation and lipemia and how this modulates new age diseases such as inflammatory bowel disease and atherosclerosis. Lastly, we explain the latest research on metaflammation and inflammaging. This review focuses on multiple signaling pathways, including, but not limited to, the FGF21-β-hydroxybutryate-NLRP3 axis, the GCN2-eIF2α-ATF4 pathway, the von Hippel-Lindau/hypoxia-inducible transcription factor pathway and the TMAO-PERK-FoxO1 axis. Additionally, throughout the review, we explain how the gut microbiota responds to altered nutrient status and also how antimicrobial peptides generated from nutrient-based signaling pathways can modulate the gut microbiota. Collectively, it must be emphasized that metabolic starvation and inflammation are strongly regulated by both environmental (i.e., nutrition, gut microbiome) and nonenvironmental (i.e., genetics) factors, which can influence the susceptibility to inflammatory disorders.
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Affiliation(s)
- Rachel M Golonka
- UT Microbiome Consortium, Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614
| | - Xia Xiao
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Ahmed A Abokor
- UT Microbiome Consortium, Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614
| | - Bina Joe
- UT Microbiome Consortium, Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614
| | - Matam Vijay-Kumar
- UT Microbiome Consortium, Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614.
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87
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Inflammation-Induced Mucosal KYNU Expression Identifies Human Ileal Crohn's Disease. J Clin Med 2020; 9:jcm9051360. [PMID: 32384670 PMCID: PMC7290775 DOI: 10.3390/jcm9051360] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 12/31/2022] Open
Abstract
The widely varying therapeutic response of patients with inflammatory bowel disease (IBD) continues to raise questions regarding the unclarified heterogeneity of pathological mechanisms promoting disease progression. While biomarkers for the differentiation of Crohn’s disease (CD) versus ulcerative colitis (UC) have been suggested, specific markers for a CD subclassification in ileal CD versus colonic CD are still rare. Since an altered signature of the tryptophan metabolism is associated with chronic inflammatory disease, we sought to characterize potential biomarkers by focusing on the downstream enzymes and metabolites of kynurenine metabolism. Using immunohistochemical stainings, we analyzed and compared the mucosal tryptophan immune metabolism in bioptic samples from patients with active inflammation due to UC or CD versus healthy controls. Localization-specific quantification of immune cell infiltration, tryptophan-metabolizing enzyme expression and mucosal tryptophan downstream metabolite levels was performed. We found generally increased immune cell infiltrates in the tissue of all patients with IBD. However, in patients with CD, significant differences were found between regulatory T cell and neutrophil granulocyte infiltration in the ileum compared with the colon. Furthermore, we observed decreased kynurenine levels as well as strong kynureninase (KYNU) expression specifically in patients with ileal CD. Correspondingly, significantly elevated levels of the kynurenine metabolite 3-hydroxyanthranilic acid were detected in the ileal CD samples. Highlighting the heterogeneity of the different phenotypes of CD, we identified KYNU as a potential mucosal biomarker allowing the localization-specific differentiation of ileal CD versus colonic CD.
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88
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Lee KH, Song Y, Wu W, Yu K, Zhang G. The gut microbiota, environmental factors, and links to the development of food allergy. Clin Mol Allergy 2020; 18:5. [PMID: 32265597 PMCID: PMC7119288 DOI: 10.1186/s12948-020-00120-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 02/17/2020] [Indexed: 12/24/2022] Open
Abstract
Food allergy appears to have its roots in an insufficient exposure to a diverse range of environmental microbiota during early life. Microbial exposure ensures the colonization of the gastrointestinal tract with commensal microbes, which is necessary for the induction of a balanced and tolerogenic immune function. High-throughput sequencing technology has facilitated in-depth studies of the gut microbiota as well as bacterial-derived metabolites. Although the role of the microbiota in allergies is now widely studied, its importance for food allergy was only recently noted. Studies in human cohorts have shown that there is an association of dysbiosis and pathogenesis of food allergy, while studies from animal models have demonstrated the capacity of specific species in the gut microbiota to alter immune response, which may lead to the desensitization of food allergy. This article reviews the role of the gut microbiota in food allergy, and discusses the influence of environmental factors as well as prevention and management strategies relating to such regulatory mechanism.
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Affiliation(s)
- Khui Hung Lee
- 1School of Public Health, Curtin University of Technology, Bentley, WA Australia.,2Curtin Health and Innovation Research Institute, Curtin University, Perth, WA 6102 Australia
| | - Yong Song
- 1School of Public Health, Curtin University of Technology, Bentley, WA Australia
| | - Weidong Wu
- 3School of Public Health, Xinxiang Medical University, 601 Jinsui street, Xinxiang, Henan China
| | - Kan Yu
- 4School of Science, Edith Cowan University, Joondalup, WA Australia
| | - Guicheng Zhang
- 1School of Public Health, Curtin University of Technology, Bentley, WA Australia.,2Curtin Health and Innovation Research Institute, Curtin University, Perth, WA 6102 Australia
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89
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Effects of dietary amino acids in ameliorating intestinal function during enteric challenges in broiler chickens. Anim Feed Sci Technol 2020. [DOI: 10.1016/j.anifeedsci.2019.114383] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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90
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AHR Signaling Dampens Inflammatory Signature in Neonatal Skin γδ T Cells. Int J Mol Sci 2020; 21:ijms21062249. [PMID: 32213963 PMCID: PMC7139545 DOI: 10.3390/ijms21062249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/16/2022] Open
Abstract
Background Aryl hydrocarbon receptor (AHR)-deficient mice do not support the expansion of dendritic epidermal T cells (DETC), a resident immune cell population in the murine epidermis, which immigrates from the fetal thymus to the skin around birth. Material and Methods In order to identify the gene expression changes underlying the DETC disappearance in AHR-deficient mice, we analyzed microarray RNA-profiles of DETC, sorted from the skin of two-week-old AHR-deficient mice and their heterozygous littermates. In vitro studies were done for verification, and IL-10, AHR repressor (AHRR), and c-Kit deficient mice analyzed for DETC frequency. Results We identified 434 annotated differentially expressed genes. Gene set enrichment analysis demonstrated that the expression of genes related to proliferation, ion homeostasis and morphology differed between the two mouse genotypes. Importantly, with 1767 pathways the cluster-group “inflammation” contained the majority of AHR-dependently regulated pathways. The most abundant cluster of differentially expressed genes was “inflammation.” DETC of AHR-deficient mice were inflammatory active and had altered calcium and F-actin levels. Extending the study to the AHRR, an enigmatic modulator of AHR-activity, we found approximately 50% less DETC in AHRR-deficient mice than in wild-type-littermates. Conclusion AHR-signaling in DETC dampens their inflammatory default potential and supports their homeostasis in the skin.
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91
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Gut Microbial-Derived Metabolomics of Asthma. Metabolites 2020; 10:metabo10030097. [PMID: 32155960 PMCID: PMC7142494 DOI: 10.3390/metabo10030097] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 12/26/2022] Open
Abstract
In this review, we discuss gut microbial-derived metabolites involved with the origins and pathophysiology of asthma, a chronic respiratory disease that is influenced by the microbiome. Although both gut and airway microbiomes may be important in asthma development, we focus here on the gut microbiome and metabolomic pathways involved in immune system ontogeny. Metabolite classes with existing evidence that microbial-derived products influence asthma risk include short chain fatty acids, polyunsaturated fatty acids and bile acids. While tryptophan metabolites and sphingolipids have known associations with asthma, additional research is needed to clarify the extent to which the microbiome contributes to the effects of these metabolites on asthma. These metabolite classes can influence immune function in one of two ways: (i) promoting growth or maturity of certain immune cell populations or (ii) influencing antigenic load by enhancing the number or species of specific bacteria. A more comprehensive understanding of how gut microbes and metabolites interact to modify asthma risk and morbidity will pave the way for targeted diagnostics and treatments.
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92
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Huang YS, Ogbechi J, Clanchy FI, Williams RO, Stone TW. IDO and Kynurenine Metabolites in Peripheral and CNS Disorders. Front Immunol 2020; 11:388. [PMID: 32194572 PMCID: PMC7066259 DOI: 10.3389/fimmu.2020.00388] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/18/2020] [Indexed: 12/12/2022] Open
Abstract
The importance of the kynurenine pathway in normal immune system function has led to an appreciation of its possible contribution to autoimmune disorders such as rheumatoid arthritis. Indoleamine-2,3-dioxygenase (IDO) activity exerts a protective function, limiting the severity of experimental arthritis, whereas deletion or inhibition exacerbates the symptoms. Other chronic disorder with an inflammatory component, such as atherosclerosis, are also suppressed by IDO activity. It is suggested that this overall anti-inflammatory activity is mediated by a change in the relative production or activity of Th17 and regulatory T cell populations. Kynurenines may play an anti-inflammatory role also in CNS disorders such as Huntington's disease, Alzheimer's disease and multiple sclerosis, in which signs of inflammation and neurodegeneration are involved. The possibility is discussed that in Huntington's disease kynurenines interact with other anti-inflammatory molecules such as Human Lymphocyte Antigen-G which may be relevant in other disorders. Kynurenine involvement may account for the protection afforded to animals with cerebral malaria and trypanosomiasis when they are treated with an inhibitor of kynurenine-3-monoxygenase (KMO). There is some evidence that changes in IL-10 may contribute to this protection and the relationship between kynurenines and IL-10 in arthritis and other inflammatory conditions should be explored. In addition, metabolites of kynurenine downstream of KMO, such as anthranilic acid and 3-hydroxy-anthranilic acid can influence inflammation, and the ratio of these compounds is a valuable biomarker of inflammatory status although the underlying molecular mechanisms of the changes require clarification. Hence it is essential that more effort be expended to identify their sites of action as potential targets for drug development. Finally, we discuss increasing awareness of the epigenetic regulation of IDO, for example by DNA methylation, a phenomenon which may explain differences between individuals in their susceptibility to arthritis and other inflammatory disorders.
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Affiliation(s)
- Yi-Shu Huang
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Joy Ogbechi
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Felix I Clanchy
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Richard O Williams
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Trevor W Stone
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
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93
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Flak MB, Koenis DS, Sobrino A, Smith J, Pistorius K, Palmas F, Dalli J. GPR101 mediates the pro-resolving actions of RvD5n-3 DPA in arthritis and infections. J Clin Invest 2020; 130:359-373. [PMID: 31793912 PMCID: PMC6934227 DOI: 10.1172/jci131609] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/08/2019] [Indexed: 01/04/2023] Open
Abstract
N-3 docosapentaenoic acid-derived resolvin D5 (RvD5n-3 DPA) is diurnally regulated in peripheral blood and exerts tissue-protective actions during inflammatory arthritis. Here, using an orphan GPCR screening approach coupled with functional readouts, we investigated the receptor(s) involved in mediating the leukocyte-directed actions of RvD5n-3 DPA and identified GPR101 as the top candidate. RvD5n-3 DPA bound to GPR101 with high selectivity and stereospecificity, as demonstrated by a calculated KD of approximately 6.9 nM. In macrophages, GPR101 knockdown limited the ability of RvD5n-3 DPA to upregulate cyclic adenosine monophosphate, phagocytosis of bacteria, and efferocytosis. Inhibition of this receptor in mouse and human leukocytes abrogated the pro-resolving actions of RvD5n-3 DPA, including the regulation of bacterial phagocytosis in neutrophils. Knockdown of the receptor in vivo reversed the protective actions of RvD5n-3 DPA in limiting joint and gut inflammation during inflammatory arthritis. Administration of RvD5n-3 DPA during E. coli-initiated inflammation regulated neutrophil trafficking to the site of inflammation, increased bacterial phagocytosis by neutrophils and macrophages, and accelerated the resolution of infectious inflammation. These in vivo protective actions of RvD5n-3 DPA were limited when Gpr101 was knocked down. Together, our findings demonstrate a fundamental role for GPR101 in mediating the leukocyte-directed actions of RvD5n-3 DPA.
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Affiliation(s)
- Magdalena B. Flak
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and
| | - Duco S. Koenis
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and
| | - Agua Sobrino
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and
| | - James Smith
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and
| | - Kimberly Pistorius
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and
| | - Francesco Palmas
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and
| | - Jesmond Dalli
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and,Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, Charterhouse Square, London, United Kingdom
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94
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Ogbechi J, Clanchy FI, Huang YS, Topping LM, Stone TW, Williams RO. IDO activation, inflammation and musculoskeletal disease. Exp Gerontol 2019; 131:110820. [PMID: 31884118 DOI: 10.1016/j.exger.2019.110820] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022]
Abstract
The IDO/kynurenine pathway is now established as a major regulator of immune system function. The initial enzyme, indoleamine 2,3-dioxygenase (IDO1) is induced by IFNγ, while tryptophan-2,3-dioxygenase (TDO) is induced by corticosteroids. The pathway is therefore positioned to mediate the effects of systemic inflammation or stress-induced steroids on tissue function and its expression increases with age. Disorders of the musculoskeletal system are a common feature of ageing and many of these conditions are characterized by an inflammatory state. In inflammatory arthritis and related disorders, kynurenine protects against the development of disease, while inhibition or deletion of IDO1 increases its severity. The long-term regulation of autoimmune disorders may be influenced by the epigenetic modulation of kynurenine pathway genes, with recent data suggesting that methylation of IDO may be involved. Osteoporosis is also associated with abnormalities of the kynurenine pathway, reflected in an inversion of the ratio between blood levels of the metabolites anthranilic acid and 3-hydroxy-anthranilic acid. This review discusses evidence to date on the role of the IDO/kynurenine pathway and the highly prevalent age-related disorders of osteoporosis and rheumatoid arthritis and identifies key areas that require further research.
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Affiliation(s)
- Joy Ogbechi
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK
| | - Felix I Clanchy
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK
| | - Yi-Shu Huang
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK
| | - Louise M Topping
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK
| | - Trevor W Stone
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK
| | - Richard O Williams
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK.
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95
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The aryl hydrocarbon receptor: an environmental sensor integrating immune responses in health and disease. Nat Rev Immunol 2019; 19:184-197. [PMID: 30718831 DOI: 10.1038/s41577-019-0125-8] [Citation(s) in RCA: 638] [Impact Index Per Article: 127.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The environment, diet, microbiota and body's metabolism shape complex biological processes in health and disease. However, our understanding of the molecular pathways involved in these processes is still limited. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that integrates environmental, dietary, microbial and metabolic cues to control complex transcriptional programmes in a ligand-specific, cell-type-specific and context-specific manner. In this Review, we summarize our current knowledge of AHR and the transcriptional programmes it controls in the immune system. Finally, we discuss the role of AHR in autoimmune and neoplastic diseases of the central nervous system, with a special focus on the gut immune system, the gut-brain axis and the therapeutic potential of targeting AHR in neurological disorders.
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96
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New therapeutic approaches to target gut-brain axis dysfunction during anorexia nervosa. CLINICAL NUTRITION EXPERIMENTAL 2019. [DOI: 10.1016/j.yclnex.2019.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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97
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Geginat J, Vasco M, Gerosa M, Tas SW, Pagani M, Grassi F, Flavell RA, Meroni P, Abrignani S. IL-10 producing regulatory and helper T-cells in systemic lupus erythematosus. Semin Immunol 2019; 44:101330. [PMID: 31735515 DOI: 10.1016/j.smim.2019.101330] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Systemic lupus erythematosus (SLE) is a highly heterogeneous autoimmune disease characterised by the production of pathogenic autoantibodies against nuclear self-antigens. The anti-inflammatory and tolerogenic cytokine Interleukin-10 appears to play a paradoxical pathogenic role in SLE and is therefore currently therapeutically targeted in clinical trials. It is generally assumed that the pathogenic effect of IL-10 in SLE is due to its growth and differentiation factor activity on autoreactive B-cells, but effects on other cells might also play a role. To date, a unique cellular source of pathogenic IL-10 in SLE has not been identified. In this review, we focus on the contribution of different CD4+T-cell subsets to IL-10 and autoantibody production in SLE. In particular, we discuss that IL-10 produced by different subsets of adaptive regulatory T-cells, follicular helper T-cells and extra-follicular B-helper T-cells is likely to have different effects on autoreactive B-cell responses. A better understanding of the role of IL-10 in B-cell responses and lupus would allow to identify the most promising therapies for individual SLE patients in the future.
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Affiliation(s)
- J Geginat
- INGM-National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", Milan, Italy.
| | - M Vasco
- INGM-National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", Milan, Italy
| | - M Gerosa
- DISCCO, Department of Clinical Science and Community Health, University of Milan, Italy; ASST Istituto G. Pini, Milan, Italy
| | - S W Tas
- Amsterdam UMC, University of Amsterdam, Department of Rheumatology & Clinical Immunology and Department of Experimental Immunology, Amsterdam Infection & Immunity Institute and Amsterdam Rheumatology & immunology Center (ARC), Academic Medical Center, Amsterdam, the Netherlands
| | - M Pagani
- INGM-National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", Milan, Italy; Amsterdam UMC, University of Amsterdam, Department of Rheumatology & Clinical Immunology and Department of Experimental Immunology, Amsterdam Infection & Immunity Institute and Amsterdam Rheumatology & immunology Center (ARC), Academic Medical Center, Amsterdam, the Netherlands; Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy
| | - F Grassi
- INGM-National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", Milan, Italy; Institute for Research in Biomedicine, Bellinzona, Switzerland
| | - R A Flavell
- Department of Immunobiology, and Howard Hughes Medical Institute, School of Medicine, Yale University, New Haven, USA
| | - Pl Meroni
- Istituto Auxologico Italiano, Milano, Italy
| | - S Abrignani
- INGM-National Institute of Molecular Genetics "Romeo ed Enrica Invernizzi", Milan, Italy; DISCCO, Department of Clinical Science and Community Health, University of Milan, Italy
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98
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Abstract
Interleukin (IL)-10 is an essential anti-inflammatory cytokine and functions as a negative regulator of immune responses to microbial antigens. IL-10 is particularly important in maintaining the intestinal microbe-immune homeostasis. Loss of IL-10 promotes the development of inflammatory bowel disease (IBD) as a consequence of an excessive immune response to the gut microbiota. IL-10 also functions more generally to prevent excessive inflammation during the course of infection. Although IL-10 can be produced by virtually all cells of the innate and adaptive immune system, T cells constitute a non-redundant source for IL-10 in many cases. The various roles of T cell-derived IL-10 will be discussed in this review. Given that IL-10 is at the center of maintaining the delicate balance between effective immunity and tissue protection, it is not surprising that IL-10 expression is highly dynamic and tightly regulated. We summarize the environmental signals and molecular pathways that regulate IL-10 expression. While numerous studies have provided us with a deep understanding of IL-10 biology, the majority of findings have been made in murine models, prompting us to highlight gaps in our knowledge about T cell-derived IL-10 in the human system.
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99
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Zhang P, Hill GR. Interleukin-10 mediated immune regulation after stem cell transplantation: Mechanisms and implications for therapeutic intervention. Semin Immunol 2019; 44:101322. [PMID: 31640914 DOI: 10.1016/j.smim.2019.101322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/08/2019] [Indexed: 12/23/2022]
Abstract
Interleukin-10 (IL-10) is a multi-faceted anti-inflammatory cytokine which plays an essential role in immune tolerance. Indeed, deficiency of IL-10 or its receptor results in aberrant immune responses that lead to immunopathology. Graft-versus-host disease (GVHD) is the limiting complication of allogeneic stem cell transplantation (SCT) and results from an imbalance in pathological versus regulatory immune networks. A number of immune cells exert their immunomodulatory role through secretion of IL-10 or induction of IL-10-secreting cells after SCT. Type-1 regulatory T cells (Tr1 cells) and FoxP3+ regulatory T cells (Tregs) are predominant sources of IL-10 after SCT and the critical role of this cytokine in preventing GVHD is now established. Recently, intriguing interactions among IL-10, immune cells, commensal microbes and host tissues in the gastrointestinal (GI) tract and other barrier surfaces have been uncovered. We now understand that IL-10 secretion is dynamically modulated by the availability of antigen, co-stimulatory signals, cytokines, commensal microbes and their metabolites in the microenvironment. In this review, we provide an overview of the control of IL-10 secretion and signaling after SCT and the therapeutic interventions, with a focus on Tr1 cells.
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Affiliation(s)
- Ping Zhang
- Bone Marrow Transplantation Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, 4006, Australia.
| | - Geoffrey R Hill
- Bone Marrow Transplantation Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, 4006, Australia; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Division of Medical Oncology, The University of Washington, Seattle, WA 98109, USA.
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100
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Mashaqi S, Gozal D. Obstructive Sleep Apnea and Systemic Hypertension: Gut Dysbiosis as the Mediator? J Clin Sleep Med 2019; 15:1517-1527. [PMID: 31596218 PMCID: PMC6778338 DOI: 10.5664/jcsm.7990] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/20/2019] [Accepted: 04/23/2019] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Obstructive sleep apnea (OSA) and systemic hypertension (SH) are common and interrelated diseases. It is estimated that approximately 75% of treatment-resistant hypertension cases have an underlying OSA. Exploration of the gut microbiome is a new advance in medicine that has been linked to many comorbid illnesses, including SH and OSA. Here, we will review the literature in SH and gut dysbiosis, OSA and gut dysbiosis, and whether gut dysbiosis is common in both conditions. METHODS We reviewed the National Center for Biotechnology Information database, including PubMed and PubMed Central. We identified a total of 230 articles. The literature search was conducted using the phrase "obstructive sleep apnea and gut dysbiosis." Only original research articles were included. This yielded a total of 12 articles. RESULTS Most of the research conducted in this field was on animal models, and almost all trials confirmed that intermittent hypoxia models resulted in gut dysbiosis. Gut dysbiosis, however, can cause a state of low-grade inflammation through damage to the gut wall barrier resulting in "leaky gut." Neuroinflammation is a hallmark of the pathophysiology of OSA-induced SH. CONCLUSIONS Gut dysbiosis seems to be an important factor in the pathophysiology of OSA-induced hypertension. Reversing gut dysbiosis at an early stage through prebiotics and probiotics and fecal microbiota transplantation combined with positive airway pressure therapy may open new horizons of treatment to prevent SH. More studies are needed in humans to elicit the effect of positive airway pressure therapy on gut dysbiosis.
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Affiliation(s)
- Saif Mashaqi
- Division of Sleep Medicine, University of North Dakota School of Medicine – Sanford Health, Fargo, North Dakota
| | - David Gozal
- Department of Child Health and the Child Health Research Institute, University of Missouri School of Medicine, Columbia, Missouri
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