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Kudo Y, Sugimoto J. The Role of the Placental Enzyme Indoleamine 2,3-Dioxygenase in Normal and Abnormal Human Pregnancy. Int J Mol Sci 2024; 25:4577. [PMID: 38674162 PMCID: PMC11050494 DOI: 10.3390/ijms25084577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
The biologically significant phenomenon that the fetus can survive immune attacks from the mother has been demonstrated in mammals. The survival mechanism depends on the fetus and placenta actively defending themselves against attacks by maternal T cells, achieved through the localized depletion of the amino acid L-tryptophan by an enzyme called indoleamine 2,3-dioxygenase. These findings were entirely unexpected and pose important questions regarding diseases related to human pregnancy and their prevention during human pregnancy. Specifically, the role of this mechanism, as discovered in mice, in humans remains unknown, as does the extent to which impaired activation of this process contributes to major clinical diseases in humans. We have, thus, elucidated several key aspects of this enzyme expressed in the human placenta both in normal and abnormal human pregnancy. The questions addressed in this brief review are as follows: (1) localization and characteristics of human placental indoleamine 2,3-dioxygenas; (2) overall tryptophan catabolism in human pregnancy and a comparison of indoleamine 2,3-dioxygenase expression levels between normal and pre-eclamptic pregnancy; (3) controlling trophoblast invasion by indoleamine 2,3-dioxygenase and its relation to the pathogenesis of placenta accrete spectrum.
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Affiliation(s)
- Yoshiki Kudo
- Department of Obstetrics and Gynecology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan;
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Smith AD, Chen C, Cheung L, Ward RE, Jones BS, Pletsch EA, Dawson HD. A type 4 resistant potato starch alters the cecal microbiome and gene expression in mice fed a western diet based on NHANES data. Food Funct 2024; 15:3141-3157. [PMID: 38439638 DOI: 10.1039/d3fo04512a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
Four major types of resistant starch (RS1-4) are present in foods, all of which can alter the microbiome and are fermented in the cecum and colon to produce short-chain fatty acids (SCFAs). Type 4 RSs are chemically modified starches, not normally found in foods, but have become a popular food additive as their addition increases fiber content. Multiple studies, in humans and rodents, have explored how different RS4 affect post-prandial glucose metabolism, but fewer studies have examined the effects of RS4 consumption on the microbiome. In addition, many RS studies conducted in rodents use high-fat diets that do not approximate what is typically consumed by humans. To address this, mice were fed a Total Western Diet (TWD), based on National Health and Nutrition Examination Survey (NHANES) data that mimics the macro and micronutrient composition of a typical American diet, for six weeks, and then supplemented with 0, 2, 5, or 10% of the RS4, Versafibe 1490™ (VF), a phosphorylated and cross-linked potato starch, for an additional three weeks. The cecal contents were analyzed for SCFA content and microbiota composition. Butyrate production was increased while branched chain SCFA production decreased. The alpha-diversity of the microbiome decreased in mice fed the TWD with 10% VF 1490 added while the beta-diversity plot showed that the 5% and 10% VF groups were distinct from mice fed the TWD. Similarly, the largest changes in relative abundance of various genera were greatest in mice fed the 10% VF diet. To examine the effect of VF consumption on tissue gene expression, cecal and distal colon tissue mRNA abundance were analyzed by RNASeq. Gene expression changes were more prevalent in the cecum than the colon and in mice fed the 10% VF diet, but the number of changes was substantially lower than we previously observed in mice fed the TWD supplemented with native potato starch (RPS). These results provide additional evidence that the structure of the RS is a major factor determining its effects on the microbiome and gene expression in the cecum and colon.
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Affiliation(s)
- Allen D Smith
- Diet, Genomics, and Immunology Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Rm. 228, Bldg. 307C, BARC-East, 10, 300 Baltimore Ave., Beltsville, MD, 20705, USA.
| | - Celine Chen
- Diet, Genomics, and Immunology Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Rm. 228, Bldg. 307C, BARC-East, 10, 300 Baltimore Ave., Beltsville, MD, 20705, USA.
| | - Lumei Cheung
- Diet, Genomics, and Immunology Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Rm. 228, Bldg. 307C, BARC-East, 10, 300 Baltimore Ave., Beltsville, MD, 20705, USA.
| | - Robert E Ward
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, USA
| | - B Sky Jones
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, USA
| | - Elizabeth A Pletsch
- Diet, Genomics, and Immunology Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Rm. 228, Bldg. 307C, BARC-East, 10, 300 Baltimore Ave., Beltsville, MD, 20705, USA.
| | - Harry D Dawson
- Diet, Genomics, and Immunology Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Rm. 228, Bldg. 307C, BARC-East, 10, 300 Baltimore Ave., Beltsville, MD, 20705, USA.
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Smith AD, Chen C, Cheung L, Dawson HD. Raw potato starch alters the microbiome, colon and cecal gene expression, and resistance to Citrobacter rodentium infection in mice fed a Western diet. Front Nutr 2023; 9:1057318. [PMID: 36704785 PMCID: PMC9871501 DOI: 10.3389/fnut.2022.1057318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/05/2022] [Indexed: 01/11/2023] Open
Abstract
Resistant starches (RS) are fermented in the cecum and colon to produce short-chain fatty acids and other microbial metabolites that can alter host physiology and the composition of the microbiome. We previously showed that mice fed a Total Western Diet (TWD) based on NHANES data that mimics the composition of a typical American diet, containing resistant potato starch (RPS), produced concentration dependent changes to the cecal short-chain fatty acids, the microbiome composition as well as gene expression changes in the cecum and colon that were most prevalent in mice fed the 10% RPS diet. We were then interested in whether feeding TWD/RPS would alter the resistance to bacterial-induced colitis caused by Citrobacter rodentium (Cr), a mouse pathogen that shares 66.7% of encoded genes with Enteropathogenic Escherichia coli. Mice were fed the TWD for 6 weeks followed by a 3-weeks on the RPS diets before infecting with Cr. Fecal Cr excretion was monitored over time and fecal samples were collected for 16S sequencing. Mice were euthanized on day 12 post-infection and cecal contents collected for 16S sequencing. Cecum and colon tissues were obtained for gene expression analysis, histology and to determine the level of mucosa-associated Cr. Feeding RPS increased the percentage of mice productively infected by Cr and fecal Cr excretion on day 4 post-infection. Mice fed the TWD/10% RPS diet also had greater colonization of colonic tissue at day 12 post-infection and colonic pathology. Both diet and infection altered the fecal and cecal microbiome composition with increased levels of RPS resulting in decreased α-diversity that was partially reversed by Cr infection. RNASeq analysis identified several mechanistic pathways that could be associated with the increased colonization of Cr-infected mice fed 10% RPS. In the distal colon we found a decrease in enrichment for genes associated with T cells, B cells, genes associated with the synthesis of DHA-derived SPMs and VA metabolism/retinoic acid signaling. We also found an increase in the expression of the potentially immunosuppressive gene, Ido1. These results suggest that high-level consumption of RPS in the context of a typical American diet, may alter susceptibility to gastrointestinal bacterial infections.
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Salminen A. Role of indoleamine 2,3-dioxygenase 1 (IDO1) and kynurenine pathway in the regulation of the aging process. Ageing Res Rev 2022; 75:101573. [PMID: 35085834 DOI: 10.1016/j.arr.2022.101573] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/12/2022] [Accepted: 01/21/2022] [Indexed: 02/07/2023]
Abstract
Indoleamine 2,3-dioxygenase 1 (IDO1) is activated in chronic inflammatory states, e.g., in the aging process and age-related diseases. IDO1 enzyme catabolizes L-tryptophan (L-Trp) into kynurenine (KYN) thus stimulating the KYN pathway. The depletion of L-Trp inhibits the proliferation of immune cells in inflamed tissues and it also reduces serotonin synthesis predisposing to psychiatric disorders. Interestingly, IDO1 protein contains two immunoreceptor tyrosine-based inhibitory motifs (ITIM) which trigger suppressive signaling through the binding of PI3K p110 and SHP-1 proteins. This immunosuppressive activity is not dependent on the catalytic activity of IDO1. KYN and its metabolite, kynurenic acid (KYNA), are potent activators of the aryl hydrocarbon receptor (AhR) which can enhance immunosuppression. IDO1-KYN-AhR signaling counteracts excessive pro-inflammatory responses in acute inflammation but in chronic inflammatory states it has many harmful effects. A chronic low-grade inflammation is associated with the aging process, a state called inflammaging. There is substantial evidence that the activation of the IDO1-KYN-AhR pathway robustly increases with the aging process. The activation of IDO1-KYN-AhR signaling does not only suppress the functions of effector immune cells, probably promoting immunosenescence, but it also impairs autophagy, induces cellular senescence, and remodels the extracellular matrix as well as enhancing the development of osteoporosis and vascular diseases. I will review the function of IDO1-KYN-AhR signaling and discuss its activation with aging as an enhancer of the aging process.
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Sudar-Milovanovic E, Gluvic Z, Obradovic M, Zaric B, Isenovic ER. Tryptophan Metabolism in Atherosclerosis and Diabetes. Curr Med Chem 2022; 29:99-113. [PMID: 34269660 DOI: 10.2174/0929867328666210714153649] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/07/2021] [Accepted: 06/11/2021] [Indexed: 02/08/2023]
Abstract
The essential amino acid tryptophan (Trp) undergoes catabolism through several pathways, producing biologically active metabolites that significantly impact physiological processes. The metabolic pathway responsible for the majority of Trp catabolism is the kynurenine synthesis pathway (KP). Serotonin and melatonin are among the most essential Trp pathways degradation products. It has emerged that a strong relationship exists between alterations in Trp metabolism and the onset and progression of atherosclerosis and diabetes. Atherosclerosis is a chronic inflammatory disease of the small and medium arteries wall caused by maladaptive local immune responses, which underpins several cardiovascular diseases (CVD). Systemic low-grade immune-mediated inflammation is implicated in atherosclerosis where pro-inflammatory cytokines, such as interferon-γ (IFN-γ), play a significant role. IFN-γ upregulates the enzyme indoleamine 2,3-dioxygenase (IDO), decreasing serum levels of the Trp and increasing metabolite levels of kynurenine. Increased IDO expression and activity could accelerate the atherosclerosis process. Therefore, activated IDO inhibition could offer possible treatment options regarding atherosclerosis management. Diabetes is a chronic metabolic disease characterized by hyperglycemia that, over time, leads to severe damage to the heart, blood vessels, eyes, kidneys, and peripheral nerves. Trp serum levels and lower activity of IDO were higher in future type 2 diabetes (T2DM) patients. This article reviews recent findings on the link between mammalian Trp metabolism and its role in atherosclerosis and diabetes and outlines the intervention strategies.
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Affiliation(s)
- Emina Sudar-Milovanovic
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade,Serbia
| | - Zoran Gluvic
- Clinic for Internal Medicine, Department of Endocrinology and Diabetes, Zemun Clinical Hospital, School of Medicine, University of Belgrade, Belgrade,Serbia
| | - Milan Obradovic
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade,Serbia
| | - Bozidarka Zaric
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade,Serbia
| | - Esma R Isenovic
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade,Serbia
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Wigner P, Saluk-Bijak J, Synowiec E, Miller E, Sliwinski T, Cichon N, Bijak M. Variation of Genes Encoding Tryptophan Catabolites Pathway Enzymes in Stroke. J Clin Med 2019; 8:jcm8122133. [PMID: 31817010 PMCID: PMC6947300 DOI: 10.3390/jcm8122133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 11/16/2022] Open
Abstract
The abnormal activation of the tryptophan catabolites pathway (TRYCATs) is observed in patients suffering from cerebrovascular disease, including stroke. A previous study confirmed that lower bioavailability of tryptophan for serotonin synthesis was characterized in the patients during the acute stroke phase. Interestingly, according to various studies, polymorphisms of the genes involved in the TRYCATs pathway may modulate the risk of stroke occurrence. Therefore, this study aimed to investigate the association between the occurrence of TPH1, TPH2, KAT1, KAT2 and IDO1 polymorphisms and the risk of stroke development.The following 10 polymorphisms of the genes encoding enzymes of the TRYCATs pathway were selected: c.804-7C > A (rs10488682), c.-1668T > A (rs623580), c.803+221C > A (rs1800532), c.-173A > T (rs1799913) - TPH1, c.-1449C > A (rs7963803), and c.-844G > T (rs4570625) - TPH2. c.*456G > A of KAT1 (rs10988134), c.975-7T > C of KAT2 (rs1480544), c.-1849C > A (rs3824259) and c. -1493G > C (rs10089084) of IDO1. The study was carried out on DNA isolated from the peripheral blood taken from 107 patients after a stroke and 107 healthy volunteers. All DNA samples were genotyped using TaqMan probes. The genotypes of eight studied polymorphisms modulated the risk of stroke. No significant difference in genotype and allele frequencies of the c.804-7C > A -TPH1 (rs10488682) and c.*456G > A - KAT1 (rs10988134) polymorphisms were found between patients and controls. Having performed haplotype and gen-gen analyses, it was possible to determine that patients after a stroke and controls differed in terms of the frequency of selected genotypes and haplotypes. Among the studied polymorphisms, eight SNPs were linked with stroke risk modulation. The results obtained confirmed our hypothesis regarding the involvement of the TRYCATs pathway in the pathogenesis of stroke.
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Affiliation(s)
- Paulina Wigner
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; (P.W.)
| | - Joanna Saluk-Bijak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Ewelina Synowiec
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; (P.W.)
| | - Elzbieta Miller
- Department of Neurological Rehabilitation, Medical University of Lodz, Poland, Milionowa 14, 93-113 Lodz, Poland;
| | - Tomasz Sliwinski
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; (P.W.)
| | - Natalia Cichon
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Michal Bijak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
- Correspondence: ; Tel.: +48-42-635-43-36
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Benavente FM, Soto JA, Pizarro-Ortega MS, Bohmwald K, González PA, Bueno SM, Kalergis AM. Contribution of IDO to human respiratory syncytial virus infection. J Leukoc Biol 2019; 106:933-942. [PMID: 31091352 PMCID: PMC7166882 DOI: 10.1002/jlb.4ru0219-051rr] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/26/2019] [Accepted: 05/05/2019] [Indexed: 12/18/2022] Open
Abstract
IDO is an enzyme that participates in the degradation of tryptophan (Trp), which is an essential amino acid necessary for vital cellular processes. The degradation of Trp and the metabolites generated by the enzymatic activity of IDO can have immunomodulating effects, notably over T cells, which are particularly sensitive to the absence of Trp and leads to the inhibition of T cell activation, cell death, and the suppression of T cell effector functions. Noteworthy, T cells participate in the cellular immune response against the human respiratory syncytial virus (hRSV) and are essential for viral clearance, as well as the total recovery of the host. Furthermore, inadequate or non‐optimal polarization of T cells is often seen during the acute phase of the disease caused by this pathogen. Here, we discuss the capacity of hRSV to exploit the immunosuppressive features of IDO to reduce T cell function, thus acquiring relevant aspects during the biology of the virus. Additionally, we review studies on the influence of IDO over T cell activation and its relationship with hRSV infection.
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Affiliation(s)
- Felipe M Benavente
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jorge A Soto
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Magdalena S Pizarro-Ortega
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Karen Bohmwald
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo A González
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M Bueno
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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Co-treatment with interferon-γ and 1-methyl tryptophan ameliorates cardiac fibrosis through cardiac myofibroblasts apoptosis. Mol Cell Biochem 2019; 458:197-205. [PMID: 31006829 PMCID: PMC6616223 DOI: 10.1007/s11010-019-03542-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 02/23/2019] [Indexed: 01/07/2023]
Abstract
Cardiac remodeling characterized by cardiac fibrosis is a pathologic process occurring after acute myocardial infarction. Fibrosis can be ameliorated by interferon-gamma (IFN-γ), which is a soluble cytokine showing various effects such as anti-fibrosis, apoptosis, anti-proliferation, immunomodulation, and anti-viral activities. However, the role of IFN-γ in cardiac myofibroblasts is not well established. Therefore, we investigated the anti-fibrotic effects of IFN-γ in human cardiac myofibroblasts (hCMs) in vitro and whether indoleamine 2,3-dioxygenase (IDO), induced by IFN-γ and resulting in cell cycle arrest, plays an important role in regulating the biological activity of hCMs. After IFN-γ treatment, cell signaling pathways and DNA contents were analyzed to assess the biological activity of IFN-γ in hCMs. In addition, an IDO inhibitor (1-methyl tryptophan; 1-MT) was used to assess whether IDO plays a key role in regulating hCMs. IFN-γ significantly inhibited hCM proliferation, and IFN-γ-induced IDO expression caused cell cycle arrest in G0/G1 through tryptophan depletion. Moreover, IFN-γ treatment gradually suppressed the expression of α-smooth muscle actin. When IDO activity was inhibited by 1-MT, marked apoptosis was observed in hCMs through the induction of interferon regulatory factor, Fas, and Fas ligand. Our results suggest that IFN-γ plays key roles in anti-proliferative and anti-fibrotic activities in hCMs and further induces apoptosis via IDO inhibition. In conclusion, co-treatment with IFN-γ and 1-MT can ameliorate fibrosis in cardiac myofibroblasts through apoptosis.
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Nitz K, Lacy M, Atzler D. Amino Acids and Their Metabolism in Atherosclerosis. Arterioscler Thromb Vasc Biol 2019; 39:319-330. [DOI: 10.1161/atvbaha.118.311572] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
As a leading cause of death worldwide, cardiovascular disease is a global health concern. The development and progression of atherosclerosis, which ultimately gives rise to cardiovascular disease, has been causally linked to hypercholesterolemia. Mechanistically, the interplay between lipids and the immune system during plaque progression significantly contributes to the chronic inflammation seen in the arterial wall during atherosclerosis. Localized inflammation and increased cell-to-cell interactions may influence polarization and proliferation of immune cells via changes in amino acid metabolism. Specifically, the amino acids
l
-arginine (Arg),
l
-homoarginine (hArg) and
l
-tryptophan (Trp) have been widely studied in the context of cardiovascular disease, and their metabolism has been established as key regulators of vascular homeostasis, as well as immune cell function. Cyclic effects between endothelial cells, innate, and adaptive immune cells exist during Arg and hArg, as well as Trp metabolism, that may have distinct effects on the development of atherosclerosis. In this review, we describe the current knowledge surrounding the metabolism, biological function, and clinical perspective of Arg, hArg, and Trp in the context of atherosclerosis.
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Affiliation(s)
- Katrin Nitz
- From the Institute for Cardiovascular Prevention (K.N., M.L., D.A.), Ludwig-Maximilians-University, Munich, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany (K.N., M.L., D.A.)
| | - Michael Lacy
- From the Institute for Cardiovascular Prevention (K.N., M.L., D.A.), Ludwig-Maximilians-University, Munich, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany (K.N., M.L., D.A.)
| | - Dorothee Atzler
- From the Institute for Cardiovascular Prevention (K.N., M.L., D.A.), Ludwig-Maximilians-University, Munich, Germany
- Walther Straub Institute of Pharmacology and Toxicology (D.A.), Ludwig-Maximilians-University, Munich, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany (K.N., M.L., D.A.)
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Wigner P, Czarny P, Synowiec E, Bijak M, Talarowska M, Galecki P, Szemraj J, Sliwinski T. Variation of genes encoding KAT1, AADAT and IDO1 as a potential risk of depression development. Eur Psychiatry 2018; 52:95-103. [PMID: 29777939 DOI: 10.1016/j.eurpsy.2018.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 12/18/2022] Open
Abstract
Numerous data suggests that the disorders of tryptophan catabolites (TRYCATs) pathway, including a decreased level of tryptophan or evaluated concentration of harmful TRYCATs -kynurenine, quinolinic acid, 3-hydroxyanthranilic acid, 3-hydroxytryptophan - may cause the occurrence of DD symptoms. In this work, we assessed the relationship between single-nucleotide polymorphisms (SNPs) of KAT1, KAT2 and IDO1 gene encoding, and the risk of depression development. Our study was performed on the DNA isolated from peripheral blood of 281 depressed patients and 236 controls. We genotyped, by using TaqMan probes, four polymorphisms: c.*456G > A of KAT1 (rs10988134), c.975-7T > C of AADAT (rs1480544), c.-1849C > A (rs3824259) and c.-1493G > C(rs10089084)of IDO1. We found that only the A/A genotype of c.*456G > A - KAT1 (rs10988134) increased the risk of depression occurrence. Interestingly, when we stratified the study group according to gender, this relationship was present only in male population. However, a gene-gene analysis revealed a link between the T/T-C/C genotype of c.975-7T > C - AADAT (rs1480544)or c.-1493G > C - IDO1 (rs10089084) and C/C-C/A genotype of c.975-7T > C - AADAT (rs1480544)and c. -1849C > A - IDO1 (rs3824259) and the disease. Moreover, we found, that the c.975-7T > C - AADAT and c. *456G > A KAT1 (rs10988134) polymorphisms may modulate the effectiveness of selective serotonin reuptake inhibitors therapy. Concluding, our results confirm the hypothesis formulated in our recently published article that the SNPs of genes involved in TRYCATs pathway may modulate the risk of depression. This provides some further evidence that the pathway plays the crucial role in development of the disease.
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Affiliation(s)
- Paulina Wigner
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Ewelina Synowiec
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Michał Bijak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Monika Talarowska
- Department of Adult Psychiatry, Medical University of Lodz, Lodz, Poland
| | - Piotr Galecki
- Department of Adult Psychiatry, Medical University of Lodz, Lodz, Poland
| | - Janusz Szemraj
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Tomasz Sliwinski
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
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Li F, Zhang R, Li S, Liu J. IDO1: An important immunotherapy target in cancer treatment. Int Immunopharmacol 2017; 47:70-77. [PMID: 28365507 DOI: 10.1016/j.intimp.2017.03.024] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/17/2017] [Accepted: 03/23/2017] [Indexed: 01/01/2023]
Abstract
Indoleamine 2,3-dioxigenase 1 (IDO1) acts in pathogenic inflammatory processes and engender immune tolerance to tumor antigens. IDO1 can decrease the tryptophan and produce a series of toxic kynurenine metabolites to promote the immune toleration via GCN2 pathway, mTOR pathway, toxic effect of kynurenine and favoring differentiation of Tregs. IDO1 can be induced in most human cells, especially APCs and cancer cells through canonical and non-canonical NF-κB and Jak/STAT pathways, as well as PKC and TGF-β signaling pathways. A series of human cancers over-express IDO1 in a constitutive way. Thus, IDO1 is likely to be an attractive target for developing inhibitors of tumor treatments. Many preclinical and clinical trials have been underway and suggest that IDO1 inhibitor maybe an effective tool against a wide range of cancers. However, the IDO1 inhibitor alone had been verified that to be disappointment in achieving effective antitumor efficacy. Concentrating on its molecular mechanism in immune toleration and complex environments of cancer, IDO1 inhibitor could cooperate with chemotherapies and other immune target inhibitors to lessen the tumor.
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Affiliation(s)
- Fangxuan Li
- Department of Cancer Prevention Center, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China; National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, China
| | - Rupeng Zhang
- Department of Gastric Cancer Surgery, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China; National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, China.
| | - Shixia Li
- Department of Cancer Prevention Center, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China; National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, China
| | - Juntian Liu
- Department of Cancer Prevention Center, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China; National Clinical Research Center for Cancer, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Tianjin's Clinical Research Center for Cancer, China.
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12
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Fayyad-Kazan M, Najar M, Fayyad-Kazan H, Raicevic G, Lagneaux L. Identification and Evaluation of New Immunoregulatory Genes in Mesenchymal Stromal Cells of Different Origins: Comparison of Normal and Inflammatory Conditions. Med Sci Monit Basic Res 2017; 23:87-96. [PMID: 28336906 PMCID: PMC5378277 DOI: 10.12659/msmbr.903518] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Mesenchymal stromal cells (MSCs) possess potent immunomodulatory properties that increase their value as a cell-based therapeutic tool for managing various immune-based disorders. Over the past years, accumulated results from trials using MSCs-based therapy have shown substantial contradictions. Although the reasons underlying these discrepancies are still not completely understood, it is well known that the immunomodulatory activities mediated by distinct MSCs differ in a manner dependent on their tissue origin and adequate response to inflammation priming. Thus, characterization of new molecular pathway(s) through which distinct MSC populations can exert their immunomodulatory effects, particularly during inflammation, will undoubtedly enhance their therapeutic potential. Material/Methods After confirming their compliance with ISCT criteria, quantitative real time-PCR (qRT-PCR) was used to screen new immunoregulatory genes in MSCs, derived from adipose tissue, foreskin, Wharton’s jelly or the bone-marrow, after being cultivated under normal and inflammatory conditions. Results FGL2, GAL, SEMA4D, SEMA7A, and IDO1 genes appeared to be differentially transcribed in the different MSC populations. Moreover, these genes were not similarly modulated following MSCs-exposure to inflammatory signals. Conclusions Our observations suggest that these identified immunoregulatory genes may be considered as potential candidates to be targeted in order to enhance the immunomodulatory properties of MSCs towards more efficient clinical use.
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Affiliation(s)
- Mohammad Fayyad-Kazan
- Institute of Molecular Biology and Medicine, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Mehdi Najar
- Laboratory of Clinical Cell Therapy, Université Libre de Bruxelles (ULB), Institut Jules Bordet, Brussels, Belgium
| | - Hussein Fayyad-Kazan
- Laboratory of Cancer Biology and Molecular Immunology, Faculty of Sciences I, Lebanese University, Hadath, Lebanon
| | - Gordana Raicevic
- Laboratory of Clinical Cell Therapy, Université Libre de Bruxelles (ULB), Institut Jules Bordet, Brussels, Belgium
| | - Laurence Lagneaux
- Laboratory of Clinical Cell Therapy, Université Libre de Bruxelles (ULB), Institut Jules Bordet, Brussels, Belgium
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13
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Hoffmann TW, Pham HP, Bridonneau C, Aubry C, Lamas B, Martin-Gallausiaux C, Moroldo M, Rainteau D, Lapaque N, Six A, Richard ML, Fargier E, Le Guern ME, Langella P, Sokol H. Microorganisms linked to inflammatory bowel disease-associated dysbiosis differentially impact host physiology in gnotobiotic mice. ISME JOURNAL 2015. [PMID: 26218241 DOI: 10.1038/ismej.2015.127] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Studying host-microbiota interactions are fundamental to understanding the mechanisms involved in intestinal homeostasis and inflammation. In this work, we analyzed these interactions in mice that were mono-associated with six microorganisms that are representative of inflammatory bowel disease (IBD)-associated dysbiosis: the bacteria Bacteroides thetaiotaomicron, adhesive-invasive Escherichia coli (AIEC), Ruminococcus gnavus and Roseburia intestinalis; a yeast used as a probiotic drug, Saccharomyces boulardii CNCM I-745; and another yeast, Candida albicans. Extensive ex vivo analyses including colon transcriptomics, histology, immune response, bile acid metabolism and short-chain fatty acid production were studied. We showed that B. thetaiotaomicron had the highest impact on the immune system because it was almost able to recapitulate the effects of the entire conventional microbiota and notably induced Treg pathways. Furthermore, these analyses uncovered the effects of E. coli AIEC LF82 on indoleamine 2,3-dioxygenase expression and of S. boulardii CNCM I-745 on angiogenesis. These results were confirmed in vitro in human cell lines. Finally, our results suggested that R. gnavus has major effects on metabolism, and notably on tryptophan metabolism. This work therefore reveals that microorganisms with a potential role in intestinal homeostasis and inflammation have specific impacts on the host, and it suggests several tracks to follow to understand intestinal homeostasis and IBD pathogenesis better, providing new insights to identify novel therapeutic targets.
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Affiliation(s)
- Thomas W Hoffmann
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France
| | - Hang-Phuong Pham
- ILTOO Pharma, Institut du Cerveau et de Moelle Epinière, Hôpital Pitié Salpêtrière, Paris, France
| | - Chantal Bridonneau
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France
| | - Camille Aubry
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France
| | - Bruno Lamas
- ERL INSERM U 1157/UMR7203, Faculté de Médecine Saint-Antoine, Université Pierre et Marie Curie (UPMC), Paris, France
| | | | - Marco Moroldo
- INRA, UMR1313 GABI/CRB GADIE, Jouy en Josas, France.,AgroParisTech, UMR1313 GABI, Jouy en Josas, France
| | - Dominique Rainteau
- ERL INSERM U 1157/UMR7203, Faculté de Médecine Saint-Antoine, Université Pierre et Marie Curie (UPMC), Paris, France
| | - Nicolas Lapaque
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France
| | - Adrien Six
- Sorbonne Universités, UPMC Université Paris 06, INSERM UMR_S 959, CNRS FRE 3632, Immunology, Immunopathology, Immunotherapy (I3), Paris, France
| | - Mathias L Richard
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France
| | - Emilie Fargier
- Biocodex, Centre Recherche et Développement, Compiègne, France
| | | | - Philippe Langella
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France
| | - Harry Sokol
- INRA, UMR1319 MICALIS, Jouy en Josas, France.,AgroParisTech, UMR1319 MICALIS, Jouy en Josas, France.,ERL INSERM U 1157/UMR7203, Faculté de Médecine Saint-Antoine, Université Pierre et Marie Curie (UPMC), Paris, France.,AgroParisTech, UMR1313 GABI, Jouy en Josas, France.,Service de Gastroentérologie et Nutrition, Hôpital Saint-Antoine, Assistance Publique Hôpitaux de Paris et Université Paris 6, Paris, France
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14
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Sedlmayr P, Blaschitz A, Stocker R. The role of placental tryptophan catabolism. Front Immunol 2014; 5:230. [PMID: 24904580 PMCID: PMC4032907 DOI: 10.3389/fimmu.2014.00230] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/05/2014] [Indexed: 01/22/2023] Open
Abstract
This review discusses the mechanisms and consequences of degradation of tryptophan (Trp) in the placenta, focusing mainly on the role of indoleamine 2,3-dioxygenase-1 (IDO1), one of three enzymes catalyzing the first step of the kynurenine pathway of Trp degradation. IDO1 has been implicated in regulation of feto-maternal tolerance in the mouse. Local depletion of Trp and/or the presence of metabolites of the kynurenine pathway mediate immunoregulation and exert antimicrobial functions. In addition to the decidual glandular epithelium, IDO1 is localized in the vascular endothelium of the villous chorion and also in the endothelium of spiral arteries of the decidua. Possible consequences of IDO1-mediated catabolism of Trp in the endothelium encompass antimicrobial activity and immunosuppression, as well as relaxation of the placental vasotonus, thereby contributing to placental perfusion and growth of both placenta and fetus. It remains to be evaluated whether other enzymes mediating Trp oxidation, such as indoleamine 2,3-dioxygenase-2, Trp 2,3-dioxygenase, and Trp hydroxylase-1 are of relevance to the biology of the placenta.
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Affiliation(s)
- Peter Sedlmayr
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz , Graz , Austria
| | - Astrid Blaschitz
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz , Graz , Austria
| | - Roland Stocker
- Victor Chang Cardiac Research Institute , Darlinghurst, NSW , Australia
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15
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The role of placental indoleamine 2,3-dioxygenase in human pregnancy. Obstet Gynecol Sci 2013; 56:209-16. [PMID: 24328005 PMCID: PMC3784137 DOI: 10.5468/ogs.2013.56.4.209] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/04/2013] [Accepted: 06/18/2013] [Indexed: 11/08/2022] Open
Abstract
Munn et al. made a scientific observation of major biological importance. For the first time they showed that in the mammal the fetus does survive an immune attack mounted by the mother, and that the mechanism responsible for the survival depends on the fetus and placenta 'actively' defending itself from attack by maternal T cells by means of an enzyme indoleamine 2,3-dioxygenase (EC 1.13.11.42) dependent localised depletion of L-tryptophan. These findings raise critical questions for disease and its prevention during human pregnancy. Specifically, the role of this mechanism (discovered in mouse) in the human, and the extent to which defective activation of this process is responsible for major clinical diseases are unknown. Therefore some key facts about this enzyme expressed in the human placenta have been studied in order to test whether Munn et al.'s findings in mouse are met for human pregnancy. This short review attempts to describe our experimental work on human placental indoleamine 2,3-dioxygenase.
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16
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Sedlmayr P, Blaschitz A. Placental expression of indoleamine 2,3-dioxygenase. Wien Med Wochenschr 2012; 162:214-9. [PMID: 22717876 DOI: 10.1007/s10354-012-0082-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/16/2012] [Indexed: 12/19/2022]
Abstract
This review focuses on the placental expression of the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase-1 (IDO1) and its potential roles, which may not only encompass immunosuppression and antimicrobial activity, but also vasodilation based on the endothelial expression on both sides of the feto-maternal interface.
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Affiliation(s)
- Peter Sedlmayr
- Center for Molecular Medicine, Institute for Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria.
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17
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Improving the safety of tolerance induction: chimerism and cellular co-treatment strategies applied to vascularized composite allografts. Clin Dev Immunol 2012; 2012:107901. [PMID: 23118778 PMCID: PMC3479992 DOI: 10.1155/2012/107901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 08/17/2012] [Indexed: 12/26/2022]
Abstract
Although vascularized composite allografts (VCAs) have been performed clinically for a variety of indications, potential complications from long-term immunosuppression and graft-versus-host disease remain important barriers to widespread applications. Recently it has been demonstrated that VCAs incorporating a vascularized long bone in a rat model provide concurrent vascularized bone marrow transplantation that, itself, functions to establish hematopoietic chimerism and donor-specific tolerance following non-myeloablative conditioning of recipients. Advances such as this, which aim to improve the safety profile of tolerance induction, will help usher in an era of wider clinical VCA application for nonlife-saving reconstructions.
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18
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Loughman JA, Hunstad DA. Induction of indoleamine 2,3-dioxygenase by uropathogenic bacteria attenuates innate responses to epithelial infection. J Infect Dis 2012; 205:1830-9. [PMID: 22474038 DOI: 10.1093/infdis/jis280] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) are the chief cause of urinary tract infections. Although neutrophilic inflammation is a hallmark of disease, previous data indicate that UPEC promotes local dampening of host innate immune responses. Here, we show that UPEC attenuates innate responses to epithelial infection by inducing expression of indoleamine 2,3-dioxygenase (IDO), a host enzyme with previously defined roles in adaptive immune regulation. UPEC induced IDO expression in human uroepithelial cells and polymorphonuclear leukocytes (PMN) in vitro and in bladder tissue during murine cystitis via a noncanonical, interferon-independent pathway. In the bladders of UPEC-infected IDO-deficient mice, we observed augmented expression of proinflammatory cytokines and local inflammation, correlated with reduced survival of extracellular bacteria. Pharmacologic inhibition of IDO also increased human PMN transepithelial migration. Stimulation of IDO expression therefore represents a pathogen strategy to create local immune privilege at epithelial surfaces, attenuating innate responses to promote colonization and the establishment of infection.
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Affiliation(s)
- Jennifer A Loughman
- Department of Pediatrics, Washington University School of Medicine, Saint Louis, MO 63110-1093, USA
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19
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Novel 1-alkyl-tryptophan derivatives downregulate IDO1 and IDO2 mRNA expression induced by interferon-gamma in dendritic cells. Mol Cell Biochem 2010; 342:29-34. [DOI: 10.1007/s11010-010-0465-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2009] [Accepted: 04/12/2010] [Indexed: 10/19/2022]
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20
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Abstract
Indoleamine 2,3-dioxygenase (IDO) is a tryptophan catabolizing enzyme that has a number of immunoregulatory effects. It is expressed at high levels in the gastrointestinal tract, particularly in the small intestine, and has been implicated in the control of intestinal inflammation. However, its precise role in intestinal immunity is not well understood. This review will summarize the current state of knowledge about IDO function, particularly as it pertains to inflammatory responses in the gut.
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Affiliation(s)
- Bobby J Cherayil
- Pediatric Gastroenterology Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA.
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21
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Immunosuppression routed via the kynurenine pathway: a biochemical and pathophysiologic approach. Adv Clin Chem 2008; 45:155-97. [PMID: 18429497 DOI: 10.1016/s0065-2423(07)00007-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the past years, it has been shown that kynurenines pathway is a regulator of both the innate and the adaptive immune responses. Particularly, the initial enzyme of this pathway, indoleamine 2,3-dioxygenase (IDO), is implicated in maintaining tolerance during pregnancy, and also can be expressed in tumors to avoid the immune attack. In this chapter, we will describe how the kynurenine pathway affects the immune system with important implications both in physiology and in pathology. The incorrect activation or blockade suppressive properties of the kynurenine pathway are also implicated in a number of other diseases such as AIDS or autoimmune diseases.
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22
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Ryan JM, Barry F, Murphy JM, Mahon BP. Interferon-gamma does not break, but promotes the immunosuppressive capacity of adult human mesenchymal stem cells. Clin Exp Immunol 2007; 149:353-63. [PMID: 17521318 PMCID: PMC1941956 DOI: 10.1111/j.1365-2249.2007.03422.x] [Citation(s) in RCA: 466] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The ability of mesenchymal stem cells (MSC) to suppress alloresponsiveness is poorly understood. Herein, an allogeneic mixed lymphocyte response was used as a model to investigate the mechanisms of MSC-mediated immunomodulation. Human MSC are demonstrated to express the immunosuppressive cytokines hepatocyte growth factor (HGF), interleukin (IL)-10 and transforming growth factor (TGF)-beta1 at concentrations that suppress alloresponses in vitro. MSC also express cyclooxygenase 1 and 2 and produce prostaglandin E2 constitutively. Blocking studies with indomethacin confirmed that prostaglandins contribute to MSC-mediated allosuppression. The proinflammatory cytokine interferon (IFN)-gamma did not ablate MSC inhibition of alloantigen-driven proliferation but up-regulated HGF and TGF-beta1. IFN-gamma also induced expression of indoleamine 2,3, dioxygenase (IDO), involved in tryptophan catabolism. Use of an antagonist, 1-methyl-L-tryptophan, restored alloresponsiveness and confirmed an IDO contribution to IFN-gamma-induced immunomodulation by MSC. Addition of the tryptophan catabolite kynurenine to mixed lymphocyte reactions (MLR), blocked alloproliferation. These findings support a model where IDO exerts its effect through the local accumulation of tryptophan metabolites rather than through tryptophan depletion. Taken together, these data demonstrate that soluble factors, or products derived from MSC, modulate immune responses and suggest that MSC create an immunosuppressive microenvironment capable of modulating alloresponsiveness even in the presence of IFN-gamma.
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Affiliation(s)
- J M Ryan
- Institute of Immunology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
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23
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Jung ID, Lee CM, Jeong YI, Lee JS, Park WS, Han J, Park YM. Differential regulation of indoleamine 2,3-dioxygenase by lipopolysaccharide and interferon gamma in murine bone marrow derived dendritic cells. FEBS Lett 2007; 581:1449-56. [PMID: 17367785 DOI: 10.1016/j.febslet.2007.02.073] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 02/26/2007] [Accepted: 02/27/2007] [Indexed: 11/17/2022]
Abstract
Indoleamine 2,3-dioxygenase (IDO) is a rate-limiting enzyme in the L-tryptophan-kynurenine pathway, which converts an essential amino acid, L-tryptophan, to N-formylkynurenine. The expression of IDO increases when inflammation is induced by wounding, infection or tumor growth. Although recent studies have suggested that IDO expression is up-regulated by IFN-gamma in various cell types and that the induction of IDO can also be mediated through an IFN-gamma-independent mechanism, these mechanisms still remain unknown. In this study, we investigated whether lipopolysaccharide (LPS) induces the expression of IDO through an IFN-gamma-mediated signaling pathway or not. IFN-gamma-induced expression of IDO expression was inhibited only by JAK inhibitor I. However, LPS-induced expression of IDO was inhibited by LY294002 and SP600125 but not by JAK inhibitor I, SB203580, or U0126. These findings clearly indicate that LPS can induce the IDO expression via an IFN-gamma-independent mechanism and PI3 kinase and JNK in the LPS-induced pathway leading to IDO expression.
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Affiliation(s)
- In Duk Jung
- Department of Microbiology and Immunology and National Research Laboratory of Dendritic, Cell Differentiation and Regulation, Medical Research Institute, Pusan National University, College of Medicine, Ami-dong 1-10, Seo-gu, Busan 602-739, South Korea
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24
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Seymour RL, Ganapathy V, Mellor AL, Munn DH. A high-affinity, tryptophan-selective amino acid transport system in human macrophages. J Leukoc Biol 2006; 80:1320-7. [PMID: 16997853 DOI: 10.1189/jlb.1205727] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Tryptophan catabolism via the enzyme indoleamine 2,3-dioxygenase (IDO) allows human monocyte-derived macrophages (MDM) and other APC to suppress T cell proliferation. IDO helps protect murine fetuses from rejection by the maternal immune system and can promote tolerance and immunosuppression. For tryptophan to be catabolized by IDO, it must first enter the APC via transmembrane transport. It has been shown that MDM in vitro readily deplete tryptophan present in the extracellular medium to nanomolar levels via IDO activity; yet, no currently known amino acid transport system displays high affinity and specificity sufficiently to permit efficient uptake of tryptophan at these low concentrations. Here, we provide biochemical characterization of a novel transport system with nanomolar affinity and high selectivity for tryptophan. Tryptophan transport in MDM was predominantly sodium-independent and occurred via two distinct systems: one consistent with the known system L transporter and a second system with 100-fold higher affinity for tryptophan (Km<300 nM). Competition studies showed that the high-affinity system did not correspond to any known transporter activity and displayed a marked selectivity for tryptophan over other amino acids and tryptophan analogs. This new system was expressed at low levels in fresh monocytes but underwent selective induction during MDM differentiation. In contrast, resting human T cells expressed only the conventional system L. We speculate that the high-affinity, tryptophan-specific transport system allows MDM to take up tryptophan efficiently under conditions of low substrate concentration, such as may occur during interaction between T cells and IDO-expressing APC.
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Affiliation(s)
- Robert L Seymour
- Immunotherapy Center, CN-4141, Medical College of Georgia, Augusta, GA 30912, USA
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25
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Takikawa O. Biochemical and medical aspects of the indoleamine 2,3-dioxygenase-initiated L-tryptophan metabolism. Biochem Biophys Res Commun 2005; 338:12-9. [PMID: 16176799 DOI: 10.1016/j.bbrc.2005.09.032] [Citation(s) in RCA: 218] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 09/05/2005] [Accepted: 09/08/2005] [Indexed: 10/25/2022]
Abstract
Indoleamine 2,3-dioxygenase (EC 1.13.11.42) is a heme-containing dioxygenase which catalyzes the first and rate-limiting step in the major pathway of L-tryptophan catabolism in mammals. Much attention has recently been focused on the dioxygenase because this metabolic pathway is involved not only in a variety of physiological functions but also in many diseases. In this review, the discovery and unique catalytic properties of dioxygenase are described first, and then the recent findings regarding the dioxygenase-initiated tryptophan metabolism are summarized, with special emphasis on the detrimental role of dioxygenase in side effects of interferon-gamma and interleukin-12 (by systemic tryptophan depletion), the escape of malignant tumors from immune surveillance (by immunosuppression caused by tryptophan depletion), several neurodegenerative disorders including Alzheimer's disease (by an aberrant production of neurotoxin, quinolinic acid), and age-related cataract (due to "Kynurenilation," a novel post-translational modification of lens proteins with tryptophan-derived UV filters).
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Affiliation(s)
- Osamu Takikawa
- National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522, Japan.
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26
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Lad SP, Fukuda EY, Li J, de la Maza LM, Li E. Up-Regulation of the JAK/STAT1 Signal Pathway duringChlamydia trachomatisInfection. THE JOURNAL OF IMMUNOLOGY 2005; 174:7186-93. [PMID: 15905563 DOI: 10.4049/jimmunol.174.11.7186] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Chlamydia trachomatis infection is the most common cause of sexually transmitted disease, leading to female pelvic inflammatory disease and infertility. The disease process has been linked to cellular response to this bacterial pathogen. This obligate intracellular pathogen infects macrophages, fibroblast cells, and epithelial and endothelial cells. We show in this study that infection of cervical epithelial cells, the primary target of Chlamydia trachomatis, leads to up-regulation and activation of the JAK/STAT signal pathway. Specifically, Chlamydia trachomatis infection of HeLa 229 cells selectively induces STAT1, STAT2, and IFN-stimulated transcription factor 3gamma expression and promotes STAT1 activation. The up-regulation of STAT1 is dependent on bacterial replication, because treatment of infected cells with antibiotics prevents STAT1 up-regulation. By analysis of the gene transcriptional and cytokine expression profiles of host cells combined with the use of neutralizing Abs, we show that IFN-beta production is critical for STAT1 induction in epithelial cells. Finally, we demonstrate that the host up-regulates STAT1 to restrict bacterial infection, because Chlamydia propagates more efficiently in STAT1-null or STAT1 knockdown cells, whereas Chlamydia growth is inhibited in cells with up-regulated STAT1 expression. This study demonstrates that the infected cells up-regulate the host innate antimicrobial response to chlamydial infection. It also highlights the importance of cellular response by nonimmune cells in host clearance of chlamydial infection.
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Affiliation(s)
- Sonya P Lad
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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27
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Depboylu C, Reinhart TA, Takikawa O, Imai Y, Maeda H, Mitsuya H, Rausch D, Eiden LE, Weihe E. Brain virus burden and indoleamine-2,3-dioxygenase expression during lentiviral infection of rhesus monkey are concomitantly lowered by 6-chloro-2',3'-dideoxyguanosine. Eur J Neurosci 2004; 19:2997-3005. [PMID: 15182307 DOI: 10.1111/j.0953-816x.2004.03404.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Increased kynurenine pathway metabolism has been implicated in the aetiology of lentiviral encephalopathy. Indoleamine-2,3-dioxygenase (IDO) initiates the increased production of kynurenine pathway metabolites like quinolinic acid (QUIN). QUIN itself is elevated in AIDS-diseased monkey and human brain parenchyma and cerebrospinal fluid at levels excitotoxic for neurons in vitro. This study investigates the cellular origin of IDO biosynthesis in the brain of rhesus monkeys infected with simian immunodeficiency virus (SIV) and explores the effects of CNS-permeant antiretroviral treatment. IDO transcript and protein were absent from the brain of non-infected and SIV-infected asymptomatic monkeys. IDO biosynthesis was induced in the brain of monkeys exhibiting AIDS. Nodule and multinucleated giant cell-forming macrophages were the main sources of IDO synthesis. Treatment with the lipophilic 6-chloro-2',3'-dideoxyguanosine suppressed IDO expression in the brain of AIDS-diseased monkeys. The effectiveness of this treatment was confirmed by the reduction of virus burden and SIV-induced perivascular infiltrates, mononuclear nodules and multinucleated giant cells. Our data demonstrate that brain IDO biosynthesis is induced in a subset of monocyte-derived cells, depends on viral burden and is susceptible to antiretroviral treatment. Thus, IDO induction is associated with reversible overt inflammatory events localized to areas of active viral replication in the SIV-infected brain.
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Affiliation(s)
- Candan Depboylu
- Department of Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University, Marburg, Germany
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Ghahary A, Li Y, Tredget EE, Kilani RT, Iwashina T, Karami A, Lin X. Expression of Indoleamine 2,3-Dioxygenase in Dermal Fibroblasts Functions as a Local Immunosuppressive Factor. J Invest Dermatol 2004; 122:953-64. [PMID: 15102086 DOI: 10.1111/j.0022-202x.2004.22409.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
As a possible way of making a non-rejectable skin substitute, here, we ask the question of whether the expression of indoleamine 2,3-dioxygenase (IDO) selectively suppresses immune, but skin, cell proliferation. To address this question, a series of experiments in which adenovirus (Ad-IDO) infected IDO expressing dermal fibroblasts were co-cultured with different types of immune cells were carried out. The immune cells were then harvested and evaluated for propidium iodide (PI) positive cells by FACS analysis. TUNEL assay was also carried out to determine the apoptotic status of these cells. The results showed that the expression of IDO in dermal fibroblasts significantly induces apoptotic death of PBMC, CD4(+)-, CD8(+)- and B cell-riched primary lymphocytes, Jurkat cells, and THP-1 cells. IDO-mediated damage of immune cells was restored by an addition of tryptophan and IDO inhibitor. Using the same approaches, we also demonstrated that skin cells and endothelial cells are remarkably resistant to tryptophan-deficient environment. Furthermore, no significant difference in cell proliferation between Ad-GFP (control)- and Ad-IDO-GFP-infected either keratinocytes or fibroblasts, was found. The results of this study, therefore, suggest that the expression of IDO by dermal fibroblasts mediates immune cell damage and this may shed a new light toward developing a non-rejectable skin substitute in the future.
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Affiliation(s)
- Aziz Ghahary
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
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Littlejohn TK, Takikawa O, Truscott RJW, Walker MJ. Asp274 and his346 are essential for heme binding and catalytic function of human indoleamine 2,3-dioxygenase. J Biol Chem 2003; 278:29525-31. [PMID: 12766158 DOI: 10.1074/jbc.m301700200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
L-Tryptophan is the least abundant essential amino acid in humans. Indoleamine 2,3-dioxgyenase (IDO) is a cytosolic heme protein which, together with the hepatic enzyme tryptophan 2,3-dioxygenase, catalyzes the first and rate-limiting step in the major pathway of tryptophan metabolism, the kynurenine pathway. The physiological role of IDO is not fully understood but is of great interest, because IDO is widely distributed in human tissues, can be up-regulated via cytokines such as interferon-gamma, and can thereby modulate the levels of tryptophan, which is vital for cell growth. To identify which amino acid residues are important in substrate or heme binding in IDO, site-directed mutagenesis of conserved residues in the IDO gene was undertaken. Because it had been proposed that a histidine residue might be the proximal heme ligand in IDO, mutation to alanine of the three highly conserved histidines His16, His303, and His346 was conducted. Of these, only His346 was shown to be essential for heme binding, indicating that this histidine residue may be the proximal ligand and suggesting that neither His303 nor His16 act as the proximal ligand. Site-directed mutagenesis of Asp274 also compromised the ability of IDO to bind heme. This observation indicates that Asp274 may coordinate to heme directly as the distal ligand or is essential in maintaining the conformation of the heme pocket.
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Affiliation(s)
- Tamantha K Littlejohn
- Australian Cataract Research Foundation, Department of Chemistry, University of Wollongong, New South Wales, Australia
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Suzuki T, Yokouchi K, Kawamichi H, Yamamoto Y, Uda K, Yuasa HJ. Comparison of the sequences of Turbo and Sulculus indoleamine dioxygenase-like myoglobin genes. Gene 2003; 308:89-94. [PMID: 12711393 DOI: 10.1016/s0378-1119(03)00467-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Some archaeogastropodic molluscs, including Sulculus and Turbo, contain an unusual approximately 40 kDa myoglobin in their buccal masses. This myoglobin can bind oxygen reversibly, but has a lower oxygen affinity than vertebrate and invertebrate myoglobins. Amino acid sequences clearly show that Sulculus and Turbo myoglobins evolved not from the globin gene but from the gene for indoleamine dioxygenase (IDO), a tryptophan-degrading enzyme. The Turbo myoglobin gene has been determined to consist of 14 exons and 13 introns. Compared with the known Sulculus IDO-like myoglobin gene, all splice junctions except two are conserved exactly between the two genes. The exon/intron organization of these myoglobin genes is also highly homologous with human IDO (ten exon/nine intron structure); splice junctions of six introns were exactly conserved among the three genes, suggesting that these introns have been conserved for at least 600 million years. To look for putative IDO genes in Turbo or Sulculus, we re-examined the genomic DNA fragments amplified by PCR in full detail, and found intron 2 in two distinct Sulculus fragments (A and B). Fragment A with a 576 bp intron corresponded exactly to the myoglobin gene of Sulculus. On the other hand, fragment B, containing a 239 bp intron, differed significantly from fragment A in nucleotide and translated amino acid sequences. Detailed sequence comparison suggests that fragment B may be derived from a putative IDO gene of Sulculus.
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Affiliation(s)
- Tomohiko Suzuki
- Laboratory of Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
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31
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Bosco MC, Rapisarda A, Reffo G, Massazza S, Pastorino S, Varesio L. Macrophage activating properties of the tryptophan catabolite picolinic acid. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 527:55-65. [PMID: 15206716 DOI: 10.1007/978-1-4615-0135-0_6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Recent studies have suggested a role for aminoacid catabolites as important regulators of macrophage (Mphi) activities. We reported previously that picolinic acid (PA), a tryptophan catabolite produced under inflammatory conditions and a costimulus with IFNgamma of Mphi effector functions, is a selective inducer of the Mphi inflammatory protein-1alpha (MIP-1alpha) and -1beta (MIPs), two CC-chemokines involved in the elicitation of the inflammatory reactions and in the development of the Th1 responses. In this study, we have investigated the effects of IFNgamma on PA-induced MIPs expression and secretion by mouse Mphi as well as the regulation of MIP-1alpha/beta receptor, CCR5, by both stimuli alone or in combination. We demonstrated that IFNgamma inhibited MIPs mRNA stimulation by PA in a dose-and time-dependent fashion, despite its ability to induce other CC- or CXC chemokines. MIPs mRNA down-regulation was associated with decreased intracellular chemokine expression and secretion and was dependent on both mRNA destabilization and gene transcription inhibition. Moreover, IFNgamma inhibitory effects were stimulus-specific because MIPs induction by PA was either unaffected or increased by the anti-inflammatory cytokines, IL-10 and IL-4, or the pro-inflammatory stimulus, LPS, respectively. In contrast, we found that IFNgamma increased CCR5 basal expression, whereas PA down-regulated both constitutive and IFNgamma-induced CCR5 mRNA and protein levels. These results demonstrate that IFNgamma and PA have reciprocal effects on the production of MIPs chemokines and the expression of their receptor. The concerted action of IFNgamma and PA on MIP-1alpha/beta chemokine/receptor system is likely to be of pathophysiological significance and to represent an important regulatory mechanism for leukocyte recruitment and distribution into damaged tissues during inflammatory responses.
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Affiliation(s)
- Maria Carla Bosco
- Laboratory of Molecular Biology, G.Gaslini Institute, 16147 Genova, Italy.
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32
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Rodrigues MR, Rodriguez D, Henrique Catalani L, Russo M, Campa A. Interferon-gamma independent oxidation of melatonin by macrophages. J Pineal Res 2003; 34:69-74. [PMID: 12485374 DOI: 10.1034/j.1600-079x.2003.02944.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mononuclear phagocytes appear to synthesize kynurenine-like products from the oxidation of biologically active indole compounds including melatonin, catalyzed by interferon (IFN)-gamma-inducible enzyme indoleamine 2,3-dioxygenase (IDO). Concanavalin A (Con A) is a plant lectin that induces interferon-gamma (IFN-gamma) production by T cells. In this study we investigated whether Con A-primed peritoneal macrophages are able to oxidize melatonin to N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK). The AFMK production was accompanied by chemiluminescence. It was found that Con A-primed but not resident macrophages produce AFMK. Surprisingly, Con A-primed macrophages from IFN-gamma-deficient mice were as effective as macrophages from IFN-gamma-sufficient mice in oxidizing melatonin. Moreover, addition of an inhibitor of IDO (1-methyltryptophan) did not affect melatonin oxidation. Con A-primed but not resident macrophages have a significant content of myeloperoxidase (MPO) and inhibition of MPO by azide completely blocked chemiluminescence and AFMK production. Thus, our findings provide evidence that melatonin oxidation by macrophages may occur through a mechanism dependent of MPO and independent of IFN-gamma and IDO activity.
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Affiliation(s)
- Maria R Rodrigues
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brazil
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33
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van Wissen M, Snoek M, Smids B, Jansen HM, Lutter R. IFN-gamma amplifies IL-6 and IL-8 responses by airway epithelial-like cells via indoleamine 2,3-dioxygenase. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:7039-44. [PMID: 12471139 DOI: 10.4049/jimmunol.169.12.7039] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Respiratory viral infections increase inflammatory responses to concurrent or secondary bacterial challenges, thereby worsening disease outcome. This potentiation of inflammation is explained at least in part by IFN-gamma promoting increased sensitivity to TNF-alpha and LPS. We sought to determine whether and, if so, how IFN-gamma can modulate proinflammatory responses to TNF-alpha and LPS by epithelial cells, which are key effector cells in the airways. Preincubation of airway epithelial-like NCI-H292 cells with IFN-gamma resulted in a hyperresponsive IL-6 and IL-8 production to TNF-alpha and LPS. The underlying mechanism involved the induction of indoleamine 2,3-dioxygenase, which catabolized the essential amino acid, tryptophan. Depletion of tryptophan led to stabilization of IL-6 and IL-8 mRNA and increased IL-6 and IL-8 responses, whereas supplementing tryptophan largely restored these changes. This novel mechanism may be implicated in enhanced inflammatory responses to bacterial challenges following viral infection.
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Affiliation(s)
- Matthijs van Wissen
- Department of Pulmonology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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34
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Rapisarda A, Pastorino S, Massazza S, Varesio L, Bosco MC. Antagonistic effect of picolinic acid and interferon-gamma on macrophage inflammatory protein-1alpha/beta production. Cell Immunol 2002; 220:70-80. [PMID: 12718941 DOI: 10.1016/s0008-8749(03)00008-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The L-tryptophan catabolite, picolinic acid (PA), is an activator of macrophage effector functions and an inducer of macrophage inflammatory protein-1alpha (MIP-1alpha) and -1beta (MIPs). We have investigated the regulation of PA-induced MIPs production in mouse macrophages. We demonstrated a dose- and time-dependent downregulation of MIPs mRNA by the Th1 cytokine, IFN-gamma, that was associated with inhibition of intracellular chemokine production and secretion. This effect was IFN-gamma-specific because MIPs induction was unaffected by the Th2 cytokines, IL-10 and IL-4, or the proinflammatory stimulus, LPS. Moreover, MIPs downregulation by IFN-gamma was dependent on both mRNA destabilization and gene transcription inhibition. These results demonstrate that MIP-1alpha/beta production by macrophages is a tightly regulated process resulting from the interaction between inhibitory stimuli derived from the immune system and stimulatory signals of non-immunologic origin. The antagonistic effect of PA and IFN-gamma on MIPs production may be important for the regulation of the inflammatory responses in vivo.
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35
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von Bubnoff D, Matz H, Frahnert C, Rao ML, Hanau D, de la Salle H, Bieber T. FcepsilonRI induces the tryptophan degradation pathway involved in regulating T cell responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:1810-6. [PMID: 12165503 DOI: 10.4049/jimmunol.169.4.1810] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
FcepsilonRI is suspected to play a pivotal role in the pathophysiology of atopic disorders such as atopic dermatitis. In search for genes differentially regulated by FcepsilonRI on APCs, a differential cDNA bank of receptor-stimulated and unstimulated monocytes was established. By means of suppression subtractive hybridization, we identified kynurenine 3-monooxygenase and subsequently indoleamine 2,3-dioxygenase (IDO) to be overexpressed in FcepsilonRI-activated monocytes. IDO is the rate-limiting enzyme in the catabolism of the essential amino acid tryptophan. We show that cross-linking of FcepsilonRI on monocytes results in low tryptophan concentrations associated with impaired T cell stimulatory capacity. Importantly, T cell suppression could be prevented by the addition of tryptophan or inhibition of IDO. Moreover, stimulation of T cells by FcepsilonRI-activated monocytes was increased compared with T cell stimulation by nonactivated monocytes if exogenous supply of tryptophan was available. We speculate that the expression of IDO by FcepsilonRI(+) APCs in vivo allows these cells to regulate T cell responses in atopic disorders by inhibiting or stimulating T cell proliferation, depending on the metabolic environment.
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36
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Tanabe A, Egashira Y, Fukuoka SI, Shibata K, Sanada H. Purification and molecular cloning of rat 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase. Biochem J 2002; 361:567-75. [PMID: 11802786 PMCID: PMC1222339 DOI: 10.1042/0264-6021:3610567] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
2-Amino-3-carboxymuconate-6-semialdehyde decarboxylase (ACMSD; EC 4.1.1.45) is one of the important enzymes regulating tryptophan-niacin metabolism. In the present study, we purified the enzyme from rat liver and kidney, and cloned the cDNA encoding rat ACMSD. The molecular masses of rat ACMSDs purified from the liver and kidney were both estimated to be 39 kDa by SDS/PAGE. Analysis of N-terminal amino acid sequences showed that these two ACMSDs share the same sequence. An expressed sequence tag (EST) of the mouse cited from the DNA database was found to be identical with this N-terminal sequence. Reverse transcription-PCR (RT-PCR) was performed using synthetic oligonucleotide primers having the partial sequences of the EST, and then cDNAs encoding rat ACMSDs were isolated by using subsequent 3'-rapid amplification of cDNA ends and RT-PCR methods. ACMSD cDNAs isolated from liver and kidney were shown to be identical, consisting of a 1008 bp open reading frame (ORF) encoding 336 amino acid residues with a molecular mass of 38091 Da. The rat ACMSD ORF was inserted into a mammalian expression vector, before transfection into human hepatoma HepG2 cells. The transfected cells expressed ACMSD activity, whereas the enzyme activity was not detected in uninfected parental HepG2 cells. The distribution of ACMSD mRNA expression in various tissues was investigated in the rat by RT-PCR. ACMSD was expressed in the liver and kidney, but not in the other principal organs examined.
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Affiliation(s)
- Atsushi Tanabe
- Graduate School of Science and Technology, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan.
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37
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Bosco MC, Rapisarda A, Massazza S, Melillo G, Young H, Varesio L. The tryptophan catabolite picolinic acid selectively induces the chemokines macrophage inflammatory protein-1 alpha and -1 beta in macrophages. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:3283-91. [PMID: 10706721 DOI: 10.4049/jimmunol.164.6.3283] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We previously found that the tryptophan catabolite picolinic acid (PA) is a costimulus for the activation of macrophage effector functions. In this study, we have investigated the ability of PA to modulate the expression of chemokines in macrophages. We demonstrate that PA is a potent activator of the inflammatory chemokines MIP (macrophage inflammatory protein)-1 alpha and MIP-1 beta (MIPs) mRNA expression in mouse macrophages in a dose- and time-dependent fashion and through a de novo protein synthesis-dependent process. The induction by PA occurred within 3 h of treatment and reached a peak in 12 h. The stimulatory effects of PA were selective for MIPs because other chemokines, including monocyte chemoattractant protein-1, RANTES, IFN-gamma-inducible protein-10, MIP-2, and macrophage-derived chemokine, were not induced under the same experimental conditions and were not an epiphenomenon of macrophage activation because IFN-gamma did not affect MIPs expression. Induction of both MIP-1 alpha and MIP-1 beta by PA was associated with transcriptional activation and mRNA stabilization, suggesting a dual molecular mechanism of control. Iron chelation could be involved in MIPs induction by PA because iron sulfate inhibited the process and the iron-chelating agent, desferrioxamine, induced MIPs expression. We propose the existence of a new pathway leading to inflammation initiated by tryptophan catabolism that can communicate with the immune system through the production of PA, followed by secretion of chemokines by macrophages. These results establish the importance of PA as an activator of macrophage proinflammatory functions, providing the first evidence that this molecule can be biologically active without the need for a costimulatory agent.
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Affiliation(s)
- M C Bosco
- Laboratory of Molecular Biology, G. Gaslini Institute, Genova, Italy.
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38
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Kudo Y, Boyd CA. Human placental indoleamine 2,3-dioxygenase: cellular localization and characterization of an enzyme preventing fetal rejection. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1500:119-24. [PMID: 10564724 DOI: 10.1016/s0925-4439(99)00096-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In order to test the hypothesis (Munn, Zhou, Attwood, Bondarev, Conway, Marshall, Brown, Mellor, Science 281 (1998) 1191-1193) that localized placental tryptophan catabolism prevents immune rejection of the mammalian fetus, the cellular localization and characteristics of human placental indoleamine 2,3-dioxygenase (EC 1.13.11.42) were studied. The localization of indoleamine 2, 3-dioxygenase activity was determined quantitatively using cell fractionation by differential and discontinuous sucrose gradient centrifugation. Enzyme activity was looked for in isolated brush border microvillous plasma membranes of placental syncytiotrophoblast. We found that this membrane preparation (which showed a 32.4-fold purification from the starting homogenate with reference to the activity of a membrane marker enzyme, alkaline phosphatase (EC 3.1.3.1)) was strongly negatively enriched with indoleamine 2,3-dioxygenase (which showed a one twenty-fifth decrease in its specific activity). Placental indoleamine 2, 3-dioxygenase is thus not expressed in the maternal facing brush border membrane of syncytiotrophoblast. 1-Methyl-DL-tryptophan which was used by Munn et al. as a key experimental tool for inhibiting indoleamine 2,3-dioxygenase in the murine model showed a competitive inhibition of human placental indoleamine 2,3-dioxygenase with L-tryptophan. The hypothesis, based on experiments performed in mouse, may therefore be applicable to avoidance of immune rejection of the fetus in human pregnancy.
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Affiliation(s)
- Y Kudo
- Department of Human Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK.
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39
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Moroni F. Tryptophan metabolism and brain function: focus on kynurenine and other indole metabolites. Eur J Pharmacol 1999; 375:87-100. [PMID: 10443567 DOI: 10.1016/s0014-2999(99)00196-x] [Citation(s) in RCA: 233] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The synthesis of NAD (or NADP) from tryptophan involves a series of enzymes and the formation of a number of intermediates which are collectively called 'kynurenines.' In the late 1970s and early 1980s, it became clear that intraventricular administration of several 'kynurenines' could cause convulsions and that one of the 'kynurenines,' quinolinic acid, was an agonist of a sub-population of NMDA receptors and caused excitotoxic neuronal death. A related metabolite, kynurenic acid, could, on the other hand, reduce excitotoxin-induced neuronal death by antagonising ionotropic glutamate receptors. Since then, modifications in quinolinic and kynurenic acid synthesis have been proposed as a pathogenetic mechanism in Huntington's chorea and epilepsy. It was subsequently shown that a robust activation of the kynurenine pathway and a large accumulation of quinolinic acid in the central nervous system occurred in several inflammatory neurological disorders. More recently, it has been shown that 3OH-kynurenine or 3OH-anthranilic acid, two other kynurenine metabolites, may cause either apoptotic or necrotic neuronal death in cultures and that inhibitors of kynurenine hydroxylase may reduce neuronal death in in vitro and in vivo models of brain ischaemia or excitotoxicity. Finally, it has been reported that indole metabolites, indirectly linked to the kynurenine pathway, are able to modify neuronal function and animal behaviour by interacting with voltage-dependent Na+ channels. Oxindole, one of these metabolites, has sedative and anticonvulsant properties and accumulates in the blood and brain when liver function is impaired. In conclusion, a number of metabolites affecting brain function originate from tryptophan metabolism. Selective inhibitors of their forming enzymes may be useful to understand their role in physiology or as therapeutic agents in pathology.
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Affiliation(s)
- F Moroni
- Department of Preclinical and Clinical Pharmacology, University of Florence, Italy.
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40
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Munn DH, Shafizadeh E, Attwood JT, Bondarev I, Pashine A, Mellor AL. Inhibition of T cell proliferation by macrophage tryptophan catabolism. J Exp Med 1999; 189:1363-72. [PMID: 10224276 PMCID: PMC2193062 DOI: 10.1084/jem.189.9.1363] [Citation(s) in RCA: 1186] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We have recently shown that expression of the enzyme indoleamine 2, 3-dioxygenase (IDO) during murine pregnancy is required to prevent rejection of the allogeneic fetus by maternal T cells. In addition to their role in pregnancy, IDO-expressing cells are widely distributed in primary and secondary lymphoid organs. Here we show that monocytes that have differentiated under the influence of macrophage colony-stimulating factor acquire the ability to suppress T cell proliferation in vitro via rapid and selective degradation of tryptophan by IDO. IDO was induced in macrophages by a synergistic combination of the T cell-derived signals IFN-gamma and CD40-ligand. Inhibition of IDO with the 1-methyl analogue of tryptophan prevented macrophage-mediated suppression. Purified T cells activated under tryptophan-deficient conditions were able to synthesize protein, enter the cell cycle, and progress normally through the initial stages of G1, including upregulation of IL-2 receptor and synthesis of IL-2. However, in the absence of tryptophan, cell cycle progression halted at a mid-G1 arrest point. Restoration of tryptophan to arrested cells was not sufficient to allow further cell cycle progression nor was costimulation via CD28. T cells could exit the arrested state only if a second round of T cell receptor signaling was provided in the presence of tryptophan. These data reveal a novel mechanism by which antigen-presenting cells can regulate T cell activation via tryptophan catabolism. We speculate that expression of IDO by certain antigen presenting cells in vivo allows them to suppress unwanted T cell responses.
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Affiliation(s)
- D H Munn
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA.
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41
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Suzuki T, Kawamichi H, Imai K. Amino acid sequence, spectral, oxygen-binding, and autoxidation properties of indoleamine dioxygenase-like myoglobin from the gastropod mollusc Turbo cornutus. JOURNAL OF PROTEIN CHEMISTRY 1998; 17:817-26. [PMID: 9988528 DOI: 10.1023/a:1020782403070] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Myoglobin was isolated from the radular muscle of the archaeogastropod mollusc Turbo cornutus (Turbinidae). This myoglobin is a monomer carrying one protoheme group; the molecular mass was estimated by SDS-PAGE to be about 40 kDa, 2.5 times larger than that of usual myoglobin. The cDNA-derived amino acid sequence of 375 residues was determined, of which 327 residues were identified directly by chemical sequencing of internal peptides. The amino acid sequence of Turbo myoglobin showed no significant homology with any other usual 16-kDa globins, but showed 36% identity with the myoglobin from Sulculus diversicolor (Haliotiidae) and 27% identity with human indoleamine 2,3-dioxygenase, a tryptophan-degrading enzyme containing heme. Thus, the Turbo myoglobin can be counted among the myoglobins which evolved from the same ancestor as that of indoleamine 2,3-dioxygenase. The absorbance ratio of gamma to CT maximum (gamma/CT) of Turbo metmyoglobin was 17.8, indicating that this myoglobin probably possesses a histidine residue near the sixth coordination position of heme iron. The Turbo myoglobin binds oxygen reversibly. Its oxygen equilibrium properties are similar to those of Sulculus myoglobin, giving P50 = 3.5 mm Hg at pH 7.4 and 20 degrees C. The pH dependence of autoxidation of Turbo oxymyoglobin was quite different from that of mammalian myoglobin, suggesting a unique protein folding around the heme cavity of Turbo myoglobin. A kinetic analysis of autoxidation indicates that the amino acid residue with pKa = 5.4 is involved in the reaction. The autoxidation reaction was enhanced markedly at pH 7.6, but not at pH 5.5 and 6.3 in the presence of tryptophan. We suggest that a noncatalytic binding site for tryptophan, in which several dissociation groups with pKa > or = 7.6 are involved, remains in Turbo myoglobin as a relic of molecular evolution.
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Affiliation(s)
- T Suzuki
- Laboratory of Biochemistry, Faculty of Science, Kochi University, Japan.
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42
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Suzuki T, Kawamichi H, Imai K. A myoglobin evolved from indoleamine 2,3-dioxygenase, a tryptophan-degrading enzyme. Comp Biochem Physiol B Biochem Mol Biol 1998; 121:117-28. [PMID: 9972288 DOI: 10.1016/s0305-0491(98)10086-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The distribution, isolation, spectral and oxygen-binding properties, stability of ferrous state (autoxidation), amino acid sequence and gene structure of indoleamine 2,3-dioxygenase (IDO)-like myoglobins are summarized, and their evolution is discussed. Although it has long been thought that all hemoglobins and myoglobins have evolved from a common ancestral gene encoding a 14-16 kDa polypeptide, the discovery of IDO-like myoglobin from several gastropod molluscs clearly indicates that there was an alternative pathway for myoglobin evolution.
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Affiliation(s)
- T Suzuki
- Laboratory of Biochemistry, Faculty of Science, Kochi University, Japan.
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43
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Kawamichi H, Suzuki T. The cDNA-derived amino acid sequence of indoleamine dioxygenase like-myoglobin from the gastropod mollusc Omphalius pfeifferi. JOURNAL OF PROTEIN CHEMISTRY 1998; 17:651-6. [PMID: 9853679 DOI: 10.1007/bf02780966] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Myoglobin was isolated from the radular muscle of the archaegastropod mollusc Omphalius pfeifferi (Trochidae). The molecular mass was estimated by SDS-PAGE to be about 40 kDa, 2.5 times larger than that of usual myoglobin. The cDNA for Omphalius myoglobin was amplified by polymerase chain reaction, and the cDNA-derived amino acid sequence of 375 residues was determined, of which 73 residues were identified directly by the chemical sequencing of internal peptides. The amino acid sequence of Omphalius myoglobin showed no significant homology with any other usual 16-kDa globins, but showed 84% and 36% identities with indoleamine dioxygenase-like myoglobins from Battilus (Turbinidae) and Sulculus (Haliotiidae), respectively. It also shows significant homology (26% identity) with human indoleamine 2,3-dioxygenase, a tryptophan-degrading enzyme containing heme. The distribution of indoleamine dioxygenase-like myoglobins suggests that they must have arisen exclusively along the specified lineage including the three families Haliotiidae, Turbinidae, and Trochidae of Archaegastropoda in molluscan evolution.
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Affiliation(s)
- H Kawamichi
- Department of Biology, Faculty of Science, Kochi University, Japan
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Suzuki T, Imai K. Comparative studies of the indoleamine dioxygenase-like myoglobin from the abalone Sulculus diversicolor. Comp Biochem Physiol B Biochem Mol Biol 1997; 117:599-604. [PMID: 9297802 DOI: 10.1016/s0305-0491(97)00017-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The abalone Sulculus diversicolor contains abundant myoglobin in its buccal mass. The myoglobin is homodimeric and the molecular mass of the constituent polypeptide chain is 41,000 Da. The amino acid sequence and gene structure are highly homologous with those of a vertebrate tryptophan-degrading enzyme, indoleamine dioxygenase (IDO). Thus Sulculus myoglobin evolved from an IDO gene, and represents a typical case of functional convergence. The oxygen equilibrium properties of Sulculus myoglobin were examined and compared with those of myoglobins from other sources. It binds oxygen reversibly, and the P50 was determined to be 3.8 mmHg at 20 degrees C and pH 7.4, showing that the oxygen affinity of Sulculus myoglobin is significantly lower than those of usual 16 kDa myoglobins. It also displays no cooperativity (nmax: 1.02-1.06) and no alkaline Bohr effect between pH 7.0 and 7.9. The cDNA-derived amino acid sequences of vertebrate IDOs, molluscan IDO-like myoglobins and a homolog in the yeast Saccharomyces were aligned, and several amino acid residues were proposed as candidates for key residues to control the function of IDO or myoglobin.
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Affiliation(s)
- T Suzuki
- Department of Biology, Faculty of Science, Kochi University, Japan.
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Alberati-Giani D, Cesura AM, Broger C, Warren WD, Röver S, Malherbe P. Cloning and functional expression of human kynurenine 3-monooxygenase. FEBS Lett 1997; 410:407-12. [PMID: 9237672 DOI: 10.1016/s0014-5793(97)00627-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Kynurenine 3-monooxygenase, an NADPH-dependent flavin monooxygenase, catalyses the hydroxylation of L-kynurenine to L-3-hydroxykynurenine. By hybridization screening using a cDNA probe encoding the entire exon 2 of Drosophila melanogaster kynurenine 3-monooxygenase, we isolated a 2.0 kb cDNA clone coding for the corresponding human liver enzyme. The deduced amino acid sequence of the human protein consists of 486 amino acids with a predicted molecular mass of 55,762 Da. Transfection of the human cDNA in HEK-293 cells resulted in the functional expression of the enzyme with kinetic properties similar to those found for the native human protein. RNA blot analysis of human tissues revealed the presence of a major mRNA species of approximately 2.0 kb in liver, placenta and kidney.
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Affiliation(s)
- D Alberati-Giani
- Pharmaceutical Division, Preclinical Research, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
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Affiliation(s)
- Masanori Sono
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
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Nagineni CN, Pardhasaradhi K, Martins MC, Detrick B, Hooks JJ. Mechanisms of interferon-induced inhibition of Toxoplasma gondii replication in human retinal pigment epithelial cells. Infect Immun 1996; 64:4188-96. [PMID: 8926087 PMCID: PMC174355 DOI: 10.1128/iai.64.10.4188-4196.1996] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Inflammation associated with retinochoroiditis is a major complication of ocular toxoplasmosis in infants and immunocompetent individuals. Moreover, Toxoplasma gondii-induced retinal disease causes serious complications in patients with AIDS and transplant patients. The retinal pigment epithelial (RPE) cell is an important regulatory cell within the retina and is one of the cells infected with T. gondii in in vivo. We have developed a human RPE (HRPE) cell in vitro model system to evaluate T. gondii replication and the regulation of this replication by cytokines. T. gondii replication was quantitated by counting the foci of infection (plaque formation) and the numbers of tachyzoites released into the supernatant fluids. Pretreatment of cultures with recombinant human tumor necrosis factor alpha, alpha interferon (IFN-alpha), IFN-beta, or IFN-gamma for 24 h prior to inoculation inhibited T. gondii replication in a dose-dependent manner. Of these cytokines, IFN-gamma was the most potent, and T. gondii replication was completely inhibited at a concentration of 100 U/ml. The anti-toxoplasmotic activity of IFN-gamma was significantly blocked by monoclonal antibody to IFN-gamma. Treatment of the cultures with IFN-gamma from day 1 or 2 postinoculation with T. gondii also offered protection against the parasite. The anti-toxoplasmotic activity of tumor necrosis factor alpha or IFN-alpha, -beta, or -gamma in these cultures was found to be independent of the nitric oxide (NO) pathway, since NO production was not found in HRPE cells treated with these cytokines. However, addition of tryptophan to IFN-gamma-treated cells significantly reversed the inhibitory effects of IFN-gamma, suggesting that IFN-gamma acts by depleting cellular tryptophan. This effect was further confirmed by reverse transcription-PCR and Northern (RNA) blot analysis, which indicated induction of indoleamine 2,3-dioxygenase (IDO), an enzyme that converts tryptophan to kynurenine. These results indicated that interferons inhibited T. gondii replication in HRPE by NO-independent but IDO-dependent mechanisms. This in vitro model of T. gondii replication in HRPE may be useful in evaluating the effects of cytokines and drugs on T. gondii replication within the retina.
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Affiliation(s)
- C N Nagineni
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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Suzuki T, Yuasa H, Imai K. Convergent evolution. The gene structure of Sulculus 41 kDa myoglobin is homologous with that of human indoleamine dioxygenase. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1308:41-8. [PMID: 8765749 DOI: 10.1016/0167-4781(96)00059-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The abalone Sulculus diversicolor contains abundant myoglobin in its buccal mass. The myoglobin consists of 377 amino acid residues and has a molecular mass of 41 000 Da, 2.5 times larger than that of other myoglobins. Sulculus myoglobin can bind oxygen reversibly, and the P50 was determined to be 3.8 mmHg at 20 degrees C and pH 7.4, showing that the oxygen affinity of Sulculus myoglobin is lower than those of vertebrate and invertebrate myoglobins. The cDNA-derived amino acid sequence showed no significant homology with those of any other invertebrate myoglobins and hemoglobins, but surprisingly showed 35% homology with a vertebrate tryptophan-degrading enzyme, indoleamine dioxygenase (IDO). The structure of the Sulculus myoglobin gene has been determined to consist of 14 exons and 13 introns (15.3 kbp). Compared with the gene of human IDO (10 exon-9 intron structure), the splice junctions of 7 introns were exactly conserved between the two genes, suggesting that these introns have been conserved for at least 600 million years. The Sulculus gene has 5 additional introns, one of which is located outside the coding region. From these results we conclude that Sulculus myoglobin evolved from an IDO gene and represents a typical case of functional convergence. Comparison of the amino acid sequence of each exon of Sulculus myoglobin with those of usual globin sequences showed that there is no significant evolutionary relationship between them. The IDO-like myoglobin is unexpectedly widely distributed among gastropodic molluscs, such as Sulculus, Nordotis, Battilus, Omphalius and Chlorostoma.
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Affiliation(s)
- T Suzuki
- Department of Biology, Faculty of Science, Kochi University, Japan.
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Yufit T, Vining V, Wang L, Brown RR, Varga J. Inhibition of type I collagen mRNA expression independent of tryptophan depletion in interferon-gamma-treated human dermal fibroblasts. J Invest Dermatol 1995; 105:388-93. [PMID: 7665918 DOI: 10.1111/1523-1747.ep12320990] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Interferon-gamma (IFN-gamma) is a pleiotropic cytokine that modulates type I collagen synthesis. In addition, IFN-gamma also exerts potent effects on cellular tryptophan levels by inducing the expression of indoleamine 2,3-dioxygenase (IDO) and tryptophanyl-tRNA synthetase. Because recent evidence indicates that IDO-mediated oxidative tryptophan catabolism is important in cellular responses to IFN-gamma, we investigated the role of IDO in the IFN-gamma-induced modulation of type I collagen gene expression. IFN-gamma ( > or = 50 U/ml) stimulated IDO expression in human dermal fibroblasts in vitro, resulting in a > 90% depletion of tryptophan in the culture media following incubation for 48 h. Higher concentrations of IFN-gamma ( > or = 500 U/ml) caused a marked decrease in type I collagen mRNA levels. Time-course studies indicated that maximal induction of IDO mRNA expression in IFN-gamma-treated fibroblast cultures (24 h) preceded the maximal decrease in collagen mRNA (96 h). Type I collagen mRNA levels were also markedly and selectively decreased in fibroblasts maintained in tryptophan-depleted cultures. Addition of exogenous tryptophan (up to 2500 microM) to IFN-gamma-treated fibroblasts restored "normal" concentrations of tryptophan in the culture media, but did not abrogate the IFN-gamma-induced decrease in collagen mRNA. Addition of the tryptophan metabolite kynurenine, in concentrations similar to those generated in fibroblast cultures following IFN-gamma treatment for 48 h, had no significant effect on type I collagen mRNA levels. These results indicate that although IFN-gamma causes activation of IDO and enhanced tryptophan catabolism in fibroblast cultures, neither the ensuing tryptophan starvation nor the accumulation of kynurenine in the culture media can fully account for the inhibitory effects of IFN-gamma on type I collagen mRNA expression.
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Affiliation(s)
- T Yufit
- Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Varga J, Yufit T, Brown RR. Inhibition of collagenase and stromelysin gene expression by interferon-gamma in human dermal fibroblasts is mediated in part via induction of tryptophan degradation. J Clin Invest 1995; 96:475-81. [PMID: 7615820 PMCID: PMC185221 DOI: 10.1172/jci118058] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The expression of the matrix-degrading enzymes collagenase and stromelysin is modulated by a variety of biologic and pharmacologic agents. IFN-gamma has potent effects on metalloproteinase production and therefore may play an important role in preventing excessive connective tissue degradation during inflammation and repair. We investigated the mechanisms of collagenase and stromelysin regulation by IFN-gamma in human dermal fibroblasts. IFN-gamma (300 U/ml) prevented the stimulation of metalloproteinase gene expression by IL-1 beta. In addition, incubation of fibroblasts with IFN-gamma resulted in a marked increase in cellular indoleamine 2,3-dioxygenase (IDO) mRNA, a > 90% depletion of tryptophan, and a corresponding > 30-fold increase in the tryptophan metabolite kynurenine in the culture media. Reducing the concentration of tryptophan from 25 microM to 0 markedly diminished the ability of fibroblasts to increase collagenase and stromelysin mRNA and collagenase production in response to IL-1 beta. Addition of exogenous tryptophan (25-50 micrograms/ml) to cultures that had been tryptophan depleted by pretreatment with IFN-gamma for 48 h restored the fibroblast response to IL-1 beta or PMA, but had no effect on IFN-gamma-induced HLA-DR alpha chain mRNA expression. These results indicate that inhibition of collagenase and stromelysin gene expression by IFN-gamma in fibroblasts is associated with activation of IDO and enhanced cellular tryptophan metabolism. Tryptophan degradation and ensuing tryptophan depletion may account, at least in part, for the inhibitory effect of IFN-gamma on metalloproteinase production in dermal fibroblasts.
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Affiliation(s)
- J Varga
- Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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