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Eaton DL, Simon TW, Kaminski NE, Perdew GH, Nebert DW. Species differences in specific ligand-binding affinity and activation of AHR: The biological basis for calculation of relative effective potencies and toxic equivalence factors. Regul Toxicol Pharmacol 2024; 149:105598. [PMID: 38548044 DOI: 10.1016/j.yrtph.2024.105598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/25/2024] [Accepted: 03/05/2024] [Indexed: 05/01/2024]
Abstract
In 2022 the World Health Organization (WHO) published updated 'Toxic Equivalence Factors' (TEFs) for a wide variety of chlorinated dioxins, dibenzofurans and PCBs [collectively referred to as 'dioxin-like chemicals'; DLCs) that interact with the aryl hydrocarbon receptor (AHR)]. Their update used sophisticated statistical analysis of hundreds of published studies that reported estimation of 'Relative Effective Potency' (REP) values for individual DLC congeners. The weighting scheme used in their assessment of each study favored in vivo over in vitro studies and was based largely on rodent studies. In this Commentary, we highlight the large body of published studies that demonstrate large species differences in AHR-ligand activation and provide supporting evidence for our position that the WHO 2022 TEF values intended for use in human risk assessment of DLC mixtures will provide highly misleading overestimates of 'Toxic Equivalent Quotients' (TEQs), because of well-recognized striking differences in AHR ligand affinities between rodent (rat, mouse) and human. The data reviewed in our Commentary support the position that human tissue-derived estimates of REP/TEF values for individual DLC congeners, although uncertain, will provide much better, more realistic estimates of potential activation of the human AHR, when exposure to complex DLC mixtures occurs.
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Affiliation(s)
- David L Eaton
- Department of Environmental Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, USA.
| | | | - Norbert E Kaminski
- Department of Pharmacology and Toxicology, Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - Gary H Perdew
- The Pennsylvania State University, State College, PA, USA
| | - Daniel W Nebert
- Department of Environmental and Public Health Sciences, Center for Environmental Genetics, University of Cincinnati College of Medicine, USA; Department of Pediatrics & Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
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2
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Eaton DL, Simon TW, Kaminski NE, Perdew GH, Nebert DW. The 2022 revised WHO TEFs for dioxins and dioxin-like chemicals: The importance of considering the use of species-specific information to determine relative effective potency for human-based risk assessment. Regul Toxicol Pharmacol 2024; 149:105599. [PMID: 38490576 DOI: 10.1016/j.yrtph.2024.105599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/25/2024] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Affiliation(s)
- David L Eaton
- Dept. Environmental Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, USA.
| | | | - Norbert E Kaminski
- Food and Consumer Product Ingredient Safety Endowed Chair, Department of Pharmacology and Toxicology, Institute for Integrative Toxicology, Director, Center for Reseaerch on Ingredient Safety, Michigan State University, East Lansing, MI, USA
| | - Gary H Perdew
- H. Thomas and Dorothy Willits Hallowell Chair in Agricultural Sciences, The Pennsylvania State University, State College, PA, USA
| | - Daniel W Nebert
- Department of Environmental and Public Health Sciences, Center for Environmental Genetics, University of Cincinnati College of Medicine, Department of Pediatrics & Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
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Chakraborty D, Coslo DM, Murray IA, Vijay A, Patterson AD, Perdew GH. Immune cell-intrinsic Ah receptor facilitates the expression of antimicrobial REG3G in the small intestine. FASEB J 2024; 38:e23471. [PMID: 38358358 DOI: 10.1096/fj.202302319r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 01/11/2024] [Accepted: 01/23/2024] [Indexed: 02/16/2024]
Abstract
The intestinal epithelial layer is susceptible to damage by chemical, physiological and mechanical stress. While it is essential to maintain the integrity of epithelium, the biochemical pathways that contribute to the barrier function have not been completely investigated. Here we demonstrate an aryl hydrocarbon receptor (AHR)-dependent mechanism facilitating the production of the antimicrobial peptide AMP regenerating islet-derived protein 3 gamma (REG3G), which is essential for intestinal homeostasis. Genetic ablation of AHR in mice impairs pSTAT3-mediated REG3G expression and increases bacterial numbers of Segmented filamentous bacteria (SFB) and Akkermansia muciniphila in the small intestine. Studies with tissue-specific conditional knockout mice revealed that the presence of AHR in the epithelial cells of the small intestine is not required for the production of REG3G through the phosphorylated STAT3-mediated pathway. However, immune-cell-specific AHR activity is necessary for normal expression of REG3G in all regions of the small intestine. A diet rich in broccoli, capable of inducing AHR activity, increases REG3G production when compared to a semi-purified diet that is devoid of ligands that can potentially activate the AHR, thus highlighting the importance of AHR in antimicrobial function. Overall, these data suggest that homeostatic antimicrobial REG3G production is increased by an AHR pathway intrinsic to the immune cells in the small intestine.
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Affiliation(s)
- Debopriya Chakraborty
- Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Denise M Coslo
- Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Anitha Vijay
- Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
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Saha K, Subramenium Ganapathy A, Wang A, Arumugam P, Michael Morris N, Harris L, Yochum G, Koltun W, Perdew GH, Nighot M, Ma T, Nighot P. Alpha-tocopherylquinone-mediated activation of the Aryl Hydrocarbon Receptor regulates the production of inflammation-inducing cytokines and ameliorates intestinal inflammation. Mucosal Immunol 2023; 16:826-842. [PMID: 37716509 PMCID: PMC10809159 DOI: 10.1016/j.mucimm.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 09/01/2023] [Accepted: 09/09/2023] [Indexed: 09/18/2023]
Abstract
This study investigated the role of Alpha-tocopherylquinone (TQ) in regulating the intestinal immune system and the underlying mechanisms. In the experimental dextran sodium sulfate and T cell-mediated colitis models, TQ significantly reduced the mRNA levels of interleukin (IL)-6, IL-1β, IL-17A, IL-23, and tumor necrosis factor (TNF)-α and the abundance of proinflammatory macrophages, T helper (Th)17 cells, and ILC3s in the colons of wild-type mice. TQ also prevented lipopolysaccharide (LPS)-induced activation of NFκB and signal transducer and activator of transcription (Stat)-3 pathways in the human macrophage U937 cells. Pharmacological inhibition or CRISPR-Cas-9-mediated knockout of Aryl hydrocarbon Receptor (AhR) prevented the anti-inflammatory effects of TQ in the LPS-treated U937 cells. Furthermore, TQ reduced the mRNA levels of the LPS-induced pro-inflammatory cytokines in the WT but not Ahr-/- mice splenocytes. TQ also reduced IL-6R protein levels and IL-6-induced Stat-3 activation in Jurkat cells and in vitro differentiation of Th17 cells from wild-type but not Ahr-/- mice naive T cells. Additionally, TQ prevented the pro-inflammatory effects of LPS on macrophages and stimulation of T cells in human PBMCs and significantly reduced the abundance of tumor necrosis factor-α, IL-1β, and IL-6hi inflammatory macrophages and Th17 cells in surgically resected Crohn's disease (CD) tissue. Our study shows that TQ is a naturally occurring, non-toxic, and effective immune modulator that activates AhR and suppresses the Stat-3-NFκB signaling.
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Affiliation(s)
- Kushal Saha
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | | | - Alexandra Wang
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Priya Arumugam
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Nathan Michael Morris
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Leonard Harris
- Division of Colon and Rectal Surgery, Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Gregory Yochum
- Division of Colon and Rectal Surgery, Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Walter Koltun
- Division of Colon and Rectal Surgery, Department of Surgery, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Meghali Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Thomas Ma
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Prashant Nighot
- Division of Gastroenterology and Hepatology, Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA.
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Isaacs JT, Dalrymple SL, Antony L, Rosen DM, Coleman IM, Nelson PS, Kostova M, Murray IA, Perdew GH, Denmeade SR, Akinboye ES, Brennen WN. Third generation quinoline-3-carboxamide transcriptional disrupter of HDAC4, HIF-1α, and MEF-2 signaling for metastatic castration-resistant prostate cancer. Prostate 2023; 83:1470-1493. [PMID: 37559436 PMCID: PMC10559933 DOI: 10.1002/pros.24606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/15/2023] [Accepted: 07/18/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND The quinoline-3-carboxamide, Tasquinimod (TasQ), is orally active as a maintenance therapy with an on-target mechanism-of-action via allosteric binding to HDAC4. This prevents formation of the HDAC4/NCoR1/HDAC3 complex, disrupting HIF-1α transcriptional activation and repressing MEF-2 target genes needed for adaptive survival signaling in the compromised tumor micro environment. In phase 3 clinical testing against metastatic castration-resistant prostate cancer(mCRPC), TasQ (1 mg/day) increased time-to-progression, but not overall survival. METHODS TasQ analogs were chemically synthesized and tested for activity compared to the parental compound. These included HDAC4 enzymatic assays, qRT-PCR and western blot analyses of gene and protein expression following treatment, in vitro and in vivo efficacy against multiple prostate cancer models including PDXs, pharmacokinetic analyses,AHR binding and agonist assays, SPR analyses of binding to HDAC4 and NCoR1, RNAseq analysis of in vivo tumors, 3D endothelial sprouting assays, and a targeted kinase screen. Genetic knockout or knockdown controls were used when appropriate. RESULTS Here, we document that, on this regimen (1 mg/day), TasQ blood levels are 10-fold lower than the optimal concentration (≥2 μM) needed for anticancer activity, suggesting higher daily doses are needed. Unfortunately, we also demonstrate that TasQ is an arylhydrocarbon receptor (AHR) agonist, which binds with an EC50 of 1 μM to produce unwanted off-target side effects. Therefore, we screened a library of TasQ analogsto maximize on-target versus off-target activity. Using this approach, we identified ESATA-20, which has ~10-fold lower AHR agonism and 5-fold greater potency against prostate cancer patient-derived xenografts. CONCLUSION This increased therapeuticindex nominates ESATA-20 as a lead candidate forclinical development as an orally active third generation quinoline-3-carboxamide analog thatretains its on-target ability to disrupt HDAC4/HIF-1α/MEF-2-dependent adaptive survival signaling in the compromisedtumor microenvironment found in mCRPC.
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Affiliation(s)
- John T. Isaacs
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
- Department of Pharmacology and Molecular Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Susan L. Dalrymple
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
| | - Lizamma Antony
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
| | - D. Marc Rosen
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
| | - Ilsa M. Coleman
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Peter S. Nelson
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Maya Kostova
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
| | - Iain A. Murray
- Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA
| | - Gary H. Perdew
- Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA
| | - Samuel R. Denmeade
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
- Department of Pharmacology and Molecular Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Emmanuel S. Akinboye
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
| | - W. Nathaniel Brennen
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland, USA
- Department of Pharmacology and Molecular Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Patel D, Murray IA, Dong F, Annalora AJ, Gowda K, Coslo DM, Krzeminski J, Koo I, Hao F, Amin SG, Marcus CB, Patterson AD, Perdew GH. Induction of AHR Signaling in Response to the Indolimine Class of Microbial Stress Metabolites. Metabolites 2023; 13:985. [PMID: 37755265 PMCID: PMC10535990 DOI: 10.3390/metabo13090985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/28/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that plays an important role in gastrointestinal barrier function, tumorigenesis, and is an emerging drug target. The resident microbiota is capable of metabolizing tryptophan to metabolites that are AHR ligands (e.g., indole-3-acetate). Recently, a novel set of mutagenic tryptophan metabolites named indolimines have been identified that are produced by M. morganii in the gastrointestinal tract. Here, we determined that indolimine-200, -214, and -248 are direct AHR ligands that can induce Cyp1a1 transcription and subsequent CYP1A1 enzymatic activity capable of metabolizing the carcinogen benzo(a)pyrene in microsomal assays. In addition, indolimines enhance IL6 expression in a colonic tumor cell line in combination with cytokine treatment. The concentration of indolimine-248 that induces AHR transcriptional activity failed to increase DNA damage. These observations reveal an additional aspect of how indolimines may alter colonic tumorigenesis beyond mutagenic activity.
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Affiliation(s)
- Dhwani Patel
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Iain A. Murray
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Fangcong Dong
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Andrew J. Annalora
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
| | - Krishne Gowda
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Denise M. Coslo
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jacek Krzeminski
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Imhoi Koo
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Fuhua Hao
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shantu G. Amin
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Craig B. Marcus
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
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Morgan EW, Dong F, Annalora AJ, Murray IA, Wolfe T, Erickson R, Gowda K, Amin SG, Petersen KS, Kris-Etherton PM, Marcus CB, Walk ST, Patterson AD, Perdew GH. Contribution of Circulating Host and Microbial Tryptophan Metabolites Toward Ah Receptor Activation. Int J Tryptophan Res 2023; 16:11786469231182510. [PMID: 37441265 PMCID: PMC10334013 DOI: 10.1177/11786469231182510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/31/2023] [Indexed: 07/15/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that plays an integral role in homeostatic maintenance by regulating cellular functions such as cellular differentiation, metabolism, barrier function, and immune response. An important but poorly understood class of AHR activators are compounds derived from host and bacterial metabolism of tryptophan. The commensal bacteria of the gut microbiome are major producers of tryptophan metabolites known to activate the AHR, while the host also produces AHR activators through tryptophan metabolism. We used targeted mass spectrometry-based metabolite profiling to determine the presence and metabolic source of these metabolites in the sera of conventional mice, germ-free mice, and humans. Surprisingly, sera concentrations of many tryptophan metabolites are comparable between germ-free and conventional mice. Therefore, many major AHR-activating tryptophan metabolites in mouse sera are produced by the host, despite their presence in feces and mouse cecal contents. Here we present an investigation of AHR activation using a complex mixture of tryptophan metabolites to examine the biological relevance of circulating tryptophan metabolites. AHR activation is rarely studied in the context of a mixture at relevant concentrations, as we present here. The AHR activation potentials of individual and pooled metabolites were explored using cell-based assays, while ligand binding competition assays and ligand docking simulations were used to assess the detected metabolites as AHR agonists. The physiological and biomedical relevance of the identified metabolites was investigated in the context of a cell-based model for rheumatoid arthritis. We present data that reframe AHR biology to include the presence of a mixture of ubiquitous tryptophan metabolites, improving our understanding of homeostatic AHR activity and models of AHR-linked diseases.
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Affiliation(s)
- Ethan W Morgan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, USA
| | - Fangcong Dong
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Andrew J Annalora
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, USA
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Trenton Wolfe
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, USA
| | - Reece Erickson
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, USA
| | - Krishne Gowda
- Department of Pharmacology Penn State College of Medicine, Hershey, USA
| | - Shantu G Amin
- Department of Pharmacology Penn State College of Medicine, Hershey, USA
| | - Kristina S Petersen
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, USA
| | - Penny M Kris-Etherton
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, USA
| | - Craig B Marcus
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, USA
| | - Seth T Walk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
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Dong F, Annalora AJ, Murray IA, Tian Y, Marcus CB, Patterson AD, Perdew GH. Endogenous Tryptophan-Derived Ah Receptor Ligands are Dissociated from CYP1A1/1B1-Dependent Negative-Feedback. Int J Tryptophan Res 2023; 16:11786469231182508. [PMID: 37434789 PMCID: PMC10331327 DOI: 10.1177/11786469231182508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/31/2023] [Indexed: 07/13/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) exerts major roles in xenobiotic metabolism, and in immune and barrier tissue homeostasis. How AHR activity is regulated by the availability of endogenous ligands is poorly understood. Potent AHR ligands have been shown to exhibit a negative feedback loop through induction of CYP1A1, leading to metabolism of the ligand. Our recent study identified and quantified 6 tryptophan metabolites (eg, indole-3-propionic acid, and indole-3-acetic acid) in mouse and human serum, generated by the host and gut microbiome, that are present in sufficient concentrations to individually activate the AHR. Here, these metabolites are not significantly metabolized by CYP1A1/1B1 in an in vitro metabolism assay. In contrast, CYP1A1/1B metabolizes the potent endogenous AHR ligand 6-formylindolo[3,2b]carbazole. Furthermore, molecular modeling of these 6 AHR activating tryptophan metabolites within the active site of CYP1A1/1B1 reveal metabolically unfavorable docking profiles with regard to orientation with the catalytic heme center. In contrast, docking studies confirmed that 6-formylindolo[3,2b]carbazole would be a potent substrate. The lack of CYP1A1 expression in mice fails to influence serum levels of the tryptophan metabolites examined. In addition, marked induction of CYP1A1 by PCB126 exposure in mice failed to alter the serum concentrations of these tryptophan metabolites. These results suggest that certain circulating tryptophan metabolites are not susceptible to an AHR negative feedback loop and are likely important factors that mediate constitutive but low level systemic human AHR activity.
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Affiliation(s)
- Fangcong Dong
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Andrew J Annalora
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, USA
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Yuan Tian
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Craig B Marcus
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, USA
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9
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Chen X, Patterson AD, Perdew GH, Murray IA, Kellogg JJ. Molecular networking identifies an AHR-modulating benzothiazole from white button mushrooms ( Agaricus bisporus). J Funct Foods 2023; 106:105602. [PMID: 37397272 PMCID: PMC10312048 DOI: 10.1016/j.jff.2023.105602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023] Open
Abstract
Diet-derived aryl hydrocarbon receptor (AHR) ligands have potential to maintain gut health. However, among the myriad bioactive compounds from foods, identifying novel functional ligands which would significantly impact gastrointestinal health is a challenge. In this study, a novel AHR modulator is predicted, identified, and characterized in the white button mushroom (Agaricus bisporus). Using a molecular networking approach, a methylated analog to benzothiazole was indicated in white button mushrooms, which was subsequently isolated and identified as 2-amino-4-methyl-benzothiazole(2A4). Cell-based AHR transcriptional assays revealed that 2-amino-4-methyl-benzothiazole possesses agonistic activity and upregulated CYP1A1 expression. This contrasts with previous findings that whole white button mushroom extract has overall antagonistic activity in vivo, underscoring the importance of studying the roles each chemical component plays in a whole food. The findings suggest that 2-amino-4-methyl-benzothiazole is a previously unidentified AHR modulator from white button mushroom and demonstrate that molecular networking has potential to identify novel receptor modulators from natural products.
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10
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Dong F, Murray IA, Annalora A, Coslo D, Desai D, Gowda K, Yang J, Wang D, Koo I, Hao F, Amin SG, Patterson AD, Marcus C, Perdew GH. Complex chemical signals dictate Ah receptor activation through the gut-lung axis. FASEB J 2023; 37:e23010. [PMID: 37272852 PMCID: PMC10264151 DOI: 10.1096/fj.202300703r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 06/06/2023]
Abstract
The aryl hydrocarbon receptor (AHR) mediates intestinal barrier homeostasis. Many AHR ligands are also CYP1A1/1B1 substrates, which can result in rapid clearance within the intestinal tract, limiting systemic exposure and subsequent AHR activation. This led us to the hypothesis that there are dietary substrates of CYP1A1/1B1 that functionally increase the half-life of potent AHR ligands. We examined the potential of urolithin A (UroA), a gut bacterial metabolite of ellagitannins, as a CYP1A1/1B1 substrate to enhance AHR activity in vivo. UroA is a competitive substrate for CYP1A1/1B1 in an in vitro competition assay. A broccoli-containing diet promotes the gastric formation of the potent hydrophobic AHR ligand and CYP1A1/1B1 substrate, 5,11-dihydroindolo[3,2-b]carbazole (ICZ). In mice, dietary exposure to UroA in a 10% broccoli diet led to a coordinated increase in duodenal, cardiac, and pulmonary AHR activity, but no increase in activity in the liver. Thus, CYP1A1 dietary competitive substrates can lead to enhanced systemic AHR ligand distribution from the gut, likely through the lymphatic system, increasing AHR activation in key barrier tissues. Finally, this report will lead to a reassessment of the dynamics of distribution of other hydrophobic chemicals present in the diet.
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Affiliation(s)
- Fangcong Dong
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Iain A. Murray
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Andrew Annalora
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, USA
| | - Denise Coslo
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Dhimant Desai
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, 17033 USA
| | - Krishne Gowda
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, 17033 USA
| | - Jian Yang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Dingbowen Wang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Imhoi Koo
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Fuhua Hao
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shantu G. Amin
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, 17033 USA
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
| | - Craig Marcus
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, USA
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
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Patel D, Morgan EW, Dong F, Murray IA, Perdew GH. Abstract 3710: Serum tryptophan metabolites mediate constitutive AHR activity in head and neck squamous cell carcinoma cells. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-3710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
The aryl hydrocarbon receptor (AHR) is transcription factor, that is activated upon binding to various exogenous and endogenous ligands. AHR activation leads to induction of target gene expression, including the members of cytochrome P450 enzyme family that metabolize many xenobiotics. Numerous studies have shown that the AHR is involved in multiple regulatory pathways important during carcinogenesis. High level of AHR protein and activation was observed in head and neck squamous cell carcinoma (HNSCC) and has been correlated with aggressive tumor phenotypes and migratory potential. Endogenous compounds derived from host tryptophan metabolism such as kynurenine, as well as the derivatives of indole derived from bacterial tryptophan metabolism such as indole-3-propionic acid are known to activate AHR. A fundamental question not previously addressed is whether these circulating tryptophan (Tryp) metabolites can mediate persistent AHR activation within tumor tissues and its effect on tumorigenesis. The focus of our research is to determine whether the continuous exposure of Tryp metabolites at relevant concentrations leads to sustained AHR activation in HNSCC cells and its subsequent effect on tumor cell phenotypes. Here, we present data demonstrating sustained AHR activation by Tryp metabolites in two HNSCC cell lines. A total of 6 tryptophan (Tryp) metabolites present at significant levels in serum with known AHR agonist activity were identified and quantified from 40 healthy individuals on a controlled diet by LC/MS/MS. HN30 and OSC19 cells were treated with a representative pool of 6 Tryp metabolites in a cell culture system to achieve continuous exposure to the Tryp metabolites, thus mimicking blood circulation in vivo. Treated cells were collected at six different time points and AHR activation within cells was determined by measuring mRNA and protein expression of AHR target genes. The effect of Tryp pool on HN30 and OSC19 cell viability was determined. The presence of Tryp metabolites within the cells and media was quantitated by LC/MS/MS at six time points over the course of 24 h. Continuous exposure of Tryp metabolites resulted in sustained AHR activation in HN30 and OSC19 cells, confirmed by induced mRNA expression of target genes and subsequent protein levels. The LC/MS data revealed the presence of all six Tryp metabolites in media collected at all time points, suggesting no spontaneous degradation of metabolites. Tryp metabolites were detected inside the cells starting from 2 h post-treatment to the last time point 24 h. Viability assays indicated no cytotoxic effects of Tryp metabolites on cells. Overall, our work has demonstrated a pattern of sustained AHR activation in HNSCC cells resulting from continuous exposure of Tryp metabolites, supporting the concept that endogenous Tryp metabolites in HNSCC patients would impact tumor progression, metastasis, and treatment outcomes.
Citation Format: Dhwani Patel, Ethan W. Morgan, Fangcong Dong, Iain A. Murray, Gary H. Perdew. Serum tryptophan metabolites mediate constitutive AHR activity in head and neck squamous cell carcinoma cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3710.
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12
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Vijay A, Boyle NR, Kumar SM, Perdew GH, Srinivasan S, Patterson AD. Aryl hydrocarbon receptor activation affects nitrergic neuronal survival and delays intestinal motility in mice. Toxicol Sci 2023; 192:117-128. [PMID: 36782369 PMCID: PMC10025877 DOI: 10.1093/toxsci/kfad014] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Despite progress describing the effects of persistent organic pollutants (POPs) on the central nervous system, the effect of POPs on enteric nervous system (ENS) function remains underexplored. We studied the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a POP, and a potent aryl hydrocarbon receptor (AHR) ligand, on the ENS and intestinal motility in mice. C57Bl/6J mice treated with TCDD (2.4 µg/kg body weight) for 8 weeks (once per week) exhibited significant delay in intestinal motility as shown by reduced stool frequency, prolonged intestinal transit time, and a persistence of dye in the jejunum compared to control mice with maximal dye retention in the ileum. TCDD significantly increased Cyp1a1 expression, an AHR target gene, and reduced the total number of neurons and affected nitrergic neurons in cells isolated from WT mice, but not Ahr-/- mice. In immortalized fetal enteric neuronal cells, TCDD-induced nuclear translocation of AHR as well as increased Cyp1a1 expression. AHR activation did not affect neuronal proliferation. However, AHR activation resulted in enteric neuronal toxicity, specifically, nitrergic neurons. Our results demonstrate that TCDD adversely affects nitrergic neurons and thereby contributes to delayed intestinal motility. These findings suggest that AHR signaling in the ENS may play a role in modulating TCDD-induced gastrointestinal pathophysiology.
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Affiliation(s)
- Anitha Vijay
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Nina R Boyle
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Supriya M Kumar
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Shanthi Srinivasan
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
- Atlanta VA Medical Center, Decatur, Georgia, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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13
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Perdew GH, Esser C, Snyder M, Sherr DH, van den Bogaard EH, McGovern K, Fernández-Salguero PM, Coumoul X, Patterson AD. The Ah Receptor from Toxicity to Therapeutics: Report from the 5th AHR Meeting at Penn State University, USA, June 2022. Int J Mol Sci 2023; 24:5550. [PMID: 36982624 PMCID: PMC10058801 DOI: 10.3390/ijms24065550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 03/10/2023] [Indexed: 03/16/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a sensor of low-molecular-weight molecule signals that originate from environmental exposures, the microbiome, and host metabolism. Building upon initial studies examining anthropogenic chemical exposures, the list of AHR ligands of microbial, diet, and host metabolism origin continues to grow and has provided important clues as to the function of this enigmatic receptor. The AHR has now been shown to be directly involved in numerous biochemical pathways that influence host homeostasis, chronic disease development, and responses to toxic insults. As this field of study has continued to grow, it has become apparent that the AHR is an important novel target for cancer, metabolic diseases, skin conditions, and autoimmune disease. This meeting attempted to cover the scope of basic and applied research being performed to address possible applications of our basic knowledge of this receptor on therapeutic outcomes.
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Affiliation(s)
- Gary H. Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA 16802, USA
| | - Charlotte Esser
- IUF-Leibniz Research Institute for Environmental Medicine, Auf’m Hennekamp 50, 40225 Düsseldorf, Germany
| | - Megan Snyder
- Department of Environmental Health, Boston University School of Public Health, 72 East Concord Street, Boston, MA 02118, USA
| | - David H. Sherr
- Department of Environmental Health, Boston University School of Public Health, 72 East Concord Street, Boston, MA 02118, USA
| | - Ellen H. van den Bogaard
- Department of Dermatology, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Karen McGovern
- Ikena Oncology, Inc., 645 Summer Street Suite 101, Boston, MA 02210, USA
| | - Pedro M. Fernández-Salguero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas s/n, 06071 Badajoz, Spain
- Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Avenida de la Investigación s/n, 06071 Badajoz, Spain
| | - Xavier Coumoul
- INSERM UMR-S1124, 45 rue des Saints-Peères, 75006 Paris, France
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA 16802, USA
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14
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Dong F, Murray IA, Annalora A, Coslo D, Desai D, Gowda K, Yang J, Wang D, Koo I, Hao F, Amin SG, Patterson AD, Marcus C, Perdew GH. Complex chemical signals dictate Ah receptor activation through the gut-lung axis. bioRxiv 2023:2023.02.22.529529. [PMID: 36865156 PMCID: PMC9980078 DOI: 10.1101/2023.02.22.529529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The aryl hydrocarbon receptor (AHR) mediates intestinal barrier homeostasis. Many AHR ligands are also CYP1A1/1B1 substrates, which can result in the rapid clearance within the intestinal tract, limiting AHR activation. This led us to the hypothesis that there are dietary substrates of CYP1A1/1B1 that increase the half-life of potent AHR ligands. We examined the potential of urolithin A (UroA) as a CYP1A1/1B1 substrate to enhance AHR activity in vivo. UroA is a competitive substrate for CYP1A1/1B1 in an in vitro competition assay. A broccoli-containing diet promotes the gastric formation of the potent hydrophobic AHR ligand and CYP1A1/1B1 substrate, 5,11-dihydroindolo[3,2-b]carbazole (ICZ). Dietary exposure to UroA in a broccoli diet led to a coordinated increase in duodenal, cardiac, and pulmonary AHR activity, but no increase in activity in liver. Thus, CYP1A1 dietary competitive substrates can lead to intestinal "escape", likely through the lymphatic system, increasing AHR activation in key barrier tissues.
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15
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Rikken G, Smith KJ, van den Brink NJM, Smits JPH, Gowda K, Alnemri A, Kuzu GE, Murray IA, Lin JM, Smits JGA, van Vlijmen-Willems IM, Amin SG, Perdew GH, van den Bogaard EH. Lead optimization of aryl hydrocarbon receptor ligands for treatment of inflammatory skin disorders. Biochem Pharmacol 2023; 208:115400. [PMID: 36574884 DOI: 10.1016/j.bcp.2022.115400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/26/2022]
Abstract
Therapeutic aryl hydrocarbon receptor (AHR) modulating agents gained attention in dermatology as non-steroidal anti-inflammatory drugs that improve skin barrier properties. By exploiting AHR's known ligand promiscuity, we generated novel AHR modulating agents by lead optimization of a selective AHR modulator (SAhRM; SGA360). Twenty-two newly synthesized compounds were screened yielding two novel derivatives, SGA360f and SGA388, in which agonist activity led to enhanced keratinocyte terminal differentiation. SGA388 showed the highest agonist activity with potent normalization of keratinocyte hyperproliferation, restored expression of skin barrier proteins and dampening of chemokine expression by keratinocytes upon Th2-mediated inflammation in vitro. The topical application of SGA360f and SGA388 reduced acute skin inflammation in vivo by reducing cyclooxygenase levels, resulting in less neutrophilic dermal infiltrates. The minimal induction of cytochrome P450 enzyme activity, lack of cellular toxicity and mutagenicity classifies SGA360f and SGA388 as novel potential therapeutic AHR ligands and illustrates the potential of medicinal chemistry to fine-tune AHR signaling for the development of targeted therapies in dermatology and beyond.
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Affiliation(s)
- Gijs Rikken
- Department of Dermatology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Kayla J Smith
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA, USA
| | - Noa J M van den Brink
- Department of Pharmacology, Penn State College of Medicine, Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Jos P H Smits
- Department of Dermatology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Krishne Gowda
- Department of Pharmacology, Penn State College of Medicine, Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Angela Alnemri
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA, USA
| | - Gulsum E Kuzu
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA, USA
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA, USA
| | - Jyh-Ming Lin
- Metabolomics Facility, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Jos G A Smits
- Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands
| | - Ivonne M van Vlijmen-Willems
- Department of Dermatology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Shantu G Amin
- Department of Pharmacology, Penn State College of Medicine, Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA, USA.
| | - Ellen H van den Bogaard
- Department of Dermatology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands.
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Morgan EW, Dong F, Annalora A, Murray IA, Wolfe T, Erickson R, Gowda K, Amin SG, Petersen KS, Kris-Etherton PM, Marcus C, Walk ST, Patterson AD, Perdew GH. Contribution of circulating host and microbial tryptophan metabolites towards Ah receptor activation. bioRxiv 2023:2023.01.26.525691. [PMID: 36747842 PMCID: PMC9900944 DOI: 10.1101/2023.01.26.525691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that plays an integral role in homeostatic maintenance by regulating cellular functions such as cellular differentiation, metabolism, barrier function, and immune response. An important but poorly understood class of AHR activators are compounds derived from host and bacterial metabolism of tryptophan. The commensal bacteria of the gut microbiome are major producers of tryptophan metabolites known to activate the AHR, while the host also produces AHR activators through tryptophan metabolism. We used targeted mass spectrometry-based metabolite profiling to determine the presence and metabolic source of these metabolites in the sera of conventional mice, germ-free mice, and humans. Surprisingly, sera concentrations of many tryptophan metabolites are comparable between germ-free and conventional mice. Therefore, many major AHR-activating tryptophan metabolites in mouse sera are produced by the host, despite their presence in feces and mouse cecal contents. AHR activation is rarely studied in the context of a mixture at relevant concentrations, as we present here. The AHR activation potentials of individual and pooled metabolites were explored using cell-based assays, while ligand binding competition assays and ligand docking simulations were used to assess the detected metabolites as AHR agonists. The physiological and biomedical relevance of the identified metabolites was investigated in the context of cell-based models for cancer and rheumatoid arthritis. We present data here that reframe AHR biology to include the presence of ubiquitous tryptophan metabolites, improving our understanding of homeostatic AHR activity and models of AHR-linked diseases.
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Zhou X, Chakraborty D, Murray IA, Coslo D, Kehs Z, Vijay A, Ton C, Desai D, Amin SG, Patterson AD, Perdew GH. Aryl Hydrocarbon Receptor Activation Coordinates Mouse Small Intestinal Epithelial Cell Programming. J Transl Med 2023; 103:100012. [PMID: 37039146 DOI: 10.1016/j.labinv.2022.100012] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/12/2022] [Accepted: 08/12/2022] [Indexed: 01/11/2023] Open
Abstract
In the face of mechanical, chemical, microbial, and immunologic pressure, intestinal homeostasis is maintained through balanced cellular turnover, proliferation, differentiation, and self-renewal. Here, we present evidence supporting the role of the aryl hydrocarbon receptor (AHR) in the adaptive reprogramming of small intestinal gene expression, leading to altered proliferation, lineage commitment, and remodeling of the cellular repertoire that comprises the intestinal epithelium to promote intestinal resilience. Ahr gene/protein expression and transcriptional activity exhibit marked proximalHI to distalLO and cryptHI to villiLO gradients. Genetic ablation of Ahr impairs commitment/differentiation of the secretory Paneth and goblet cell lineages and associated mucin production, restricts expression of secretory/enterocyte differentiation markers, and increases crypt-associated proliferation and villi-associated enterocyte luminal exfoliation. Ahr-/- mice display a decrease in intestinal barrier function. Ahr+/+ mice that maintain a diet devoid of AHR ligands intestinally phenocopy Ahr-/- mice. In contrast, Ahr+/+ mice exposed to AHR ligands reverse these phenotypes. Ligand-induced AHR transcriptional activity positively correlates with gene expression (Math1, Klf4, Tff3) associated with differentiation of the goblet cell secretory lineage. Math1 was identified as a direct target gene of AHR, a transcription factor critical to the development of goblet cells. These data suggest that dietary cues, relayed through the transcriptional activity of AHR, can reshape the cellular repertoire of the gastrointestinal tract.
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Granados JC, Falah K, Koo I, Morgan EW, Perdew GH, Patterson AD, Jamshidi N, Nigam SK. AHR is a master regulator of diverse pathways in endogenous metabolism. Sci Rep 2022; 12:16625. [PMID: 36198709 PMCID: PMC9534852 DOI: 10.1038/s41598-022-20572-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/15/2022] [Indexed: 11/08/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a transcription factor with roles in detoxification, development, immune response, chronic kidney disease and other syndromes. It regulates the expression of drug transporters and drug metabolizing enzymes in a proposed Remote Sensing and Signaling Network involved in inter-organ communication via metabolites and signaling molecules. Here, we use integrated omics approaches to analyze its contributions to metabolism across multiple scales from the organ to the organelle. Global metabolomics analysis of Ahr-/- mice revealed the role of AHR in the regulation of 290 metabolites involved in many biochemical pathways affecting fatty acids, bile acids, gut microbiome products, antioxidants, choline derivatives, and uremic toxins. Chemoinformatics analysis suggest that AHR plays a role in determining the hydrophobicity of metabolites and perhaps their transporter-mediated movement into and out of tissues. Of known AHR ligands, indolepropionate was the only significantly altered molecule, and it activated AHR in both human and murine cells. To gain a deeper biological understanding of AHR, we employed genome scale metabolic reconstruction to integrate knockout transcriptomics and metabolomics data, which indicated a role for AHR in regulation of organic acids and redox state. Together, the results indicate a central role of AHR in metabolism and signaling between multiple organs and across multiple scales.
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Affiliation(s)
- Jeffry C Granados
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Kian Falah
- Departments of Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Imhoi Koo
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Ethan W Morgan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, State College, PA, 16801, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Neema Jamshidi
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Sanjay K Nigam
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA.
- Department of Medicine (Nephrology), University of California San Diego, La Jolla, CA, 92093, USA.
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Abstract
Microbial communities on and within the host contact environmental pollutants, toxic compounds, and other xenobiotic compounds. These communities of bacteria, fungi, viruses, and archaea possess diverse metabolic potential to catabolize compounds and produce new metabolites. Microbes alter chemical disposition thus making the microbiome a natural subject of interest for toxicology. Sequencing and metabolomics technologies permit the study of microbiomes altered by acute or long-term exposure to xenobiotics. These investigations have already contributed to and are helping to re-interpret traditional understandings of toxicology. The purpose of this review is to provide a survey of the current methods used to characterize microbes within the context of toxicology. This will include discussion of commonly used techniques for conducting omic-based experiments, their respective strengths and deficiencies, and how forward-looking techniques may address present shortcomings. Finally, a perspective will be provided regarding common assumptions that currently impede microbiome studies from producing causal explanations of toxicologic mechanisms.
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Affiliation(s)
- Ethan W Morgan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Andrew D Patterson
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Priyadarshini M, Navarro G, Reiman DJ, Sharma A, Xu K, Lednovich K, Manzella CR, Khan MW, Garcia MS, Allard S, Wicksteed B, Chlipala GE, Szynal B, Bernabe BP, Maki PM, Gill RK, Perdew GH, Gilbert J, Dai Y, Layden BT. Gestational Insulin Resistance Is Mediated by the Gut Microbiome-Indoleamine 2,3-Dioxygenase Axis. Gastroenterology 2022; 162:1675-1689.e11. [PMID: 35032499 PMCID: PMC9040389 DOI: 10.1053/j.gastro.2022.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 12/23/2021] [Accepted: 01/03/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND & AIMS Normal gestation involves a reprogramming of the maternal gut microbiome (GM) that contributes to maternal metabolic changes by unclear mechanisms. This study aimed to understand the mechanistic underpinnings of the GM-maternal metabolism interaction. METHODS The GM and plasma metabolome of CD1, NIH-Swiss, and C57 mice were analyzed with the use of 16S rRNA sequencing and untargeted liquid chromatography-mass spectrometry throughout gestation. Pharmacologic and genetic knockout mouse models were used to identify the role of indoleamine 2,3-dioxygenase (IDO1) in pregnancy-associated insulin resistance (IR). Involvement of gestational GM was studied with the use of fecal microbial transplants (FMTs). RESULTS Significant variation in GM alpha diversity occurred throughout pregnancy. Enrichment in gut bacterial taxa was mouse strain and pregnancy time point specific, with the species enriched at gestation day 15/19 (G15/19), a point of heightened IR, being distinct from those enriched before or after pregnancy. Metabolomics revealed elevated plasma kynurenine at G15/19 in all 3 mouse strains. IDO1, the rate-limiting enzyme for kynurenine production, had increased intestinal expression at G15, which was associated with mild systemic and gut inflammation. Pharmacologic and genetic inhibition of IDO1 inhibited kynurenine levels and reversed pregnancy-associated IR. FMT revealed that IDO1 induction and local kynurenine level effects on IR derive from the GM in both mouse and human pregnancy. CONCLUSIONS GM changes accompanying pregnancy shift IDO1-dependent tryptophan metabolism toward kynurenine production, intestinal inflammation, and gestational IR, a phenotype reversed by genetic deletion or inhibition of IDO1. (Gestational Gut Microbiome-IDO1 Axis Mediates Pregnancy Insulin Resistance; EMBL-ENA ID: PRJEB45047. MetaboLights ID: MTBLS3598).
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Affiliation(s)
- Medha Priyadarshini
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | - Guadalupe Navarro
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | - Derek J Reiman
- Department of Biomedical Engineering, UIC, Chicago-IL, U.S.A
| | - Anukriti Sharma
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic Main Campus, Cleveland-OH, U.S.A
| | - Kai Xu
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | - Kristen Lednovich
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | | | - Md Wasim Khan
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | - Mariana Salas Garcia
- Department of Pediatrics, University of California San Diego (UCSD) School of Medicine, La Jolla-CA, U.S.A
| | - Sarah Allard
- Department of Pediatrics, University of California San Diego (UCSD) School of Medicine, La Jolla-CA, U.S.A
| | - Barton Wicksteed
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | - George E Chlipala
- Research Informatics Core, Research Resources Center, UIC, Chicago-IL, U.S.A
| | - Barbara Szynal
- Division of Endocrinology, Diabetes, and Metabolism and UIC, Chicago-IL, U.S.A
| | | | - Pauline M Maki
- Department of Psychiatry, UIC, Chicago-IL, U.S.A.; Department of Psychology, and UIC, Chicago-IL, U.S.A.; Department of Obstetrics and Gynecology, UIC, Chicago-IL, U.S.A
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, UIC, Chicago-IL, U.S.A
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, Pennsylvania, U.S.A
| | - Jack Gilbert
- Department of Pediatrics, University of California San Diego (UCSD) School of Medicine, La Jolla-CA, U.S.A.; Scripps Institution of Oceanography, UCSD, La Jolla-CA, U.S.A
| | - Yang Dai
- Department of Biomedical Engineering, UIC, Chicago-IL, U.S.A
| | - Brian T Layden
- Division of Endocrinology, Diabetes, and Metabolism, University of Illinois, Chicago, Illinois; Jesse Brown Veterans Affair Medical Center, Chicago, Illinois.
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21
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Liu Q, Zhang L, Allman EL, Hubbard TD, Murray IA, Hao F, Tian Y, Gui W, Nichols RG, Smith PB, Anitha M, Perdew GH, Patterson AD. The aryl hydrocarbon receptor activates ceramide biosynthesis in mice contributing to hepatic lipogenesis. Toxicology 2021; 458:152831. [PMID: 34097992 DOI: 10.1016/j.tox.2021.152831] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/10/2021] [Accepted: 06/02/2021] [Indexed: 12/18/2022]
Abstract
Aryl hydrocarbon receptor (AHR) activation via 2,3,7,8-tetrachlorodibenzofuran (TCDF) induces the accumulation of hepatic lipids. Here we report that AHR activation by TCDF (24 μg/kg body weight given orally for five days) induced significant elevation of hepatic lipids including ceramides in mice, was associated with increased expression of key ceramide biosynthetic genes, and increased activity of their respective enzymes. Results from chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assay (EMSA) and cell-based reporter luciferase assays indicated that AHR directly activated the serine palmitoyltransferase long chain base subunit 2 (Sptlc2, encodes serine palmitoyltransferase 2 (SPT2)) gene whose product catalyzes the initial rate-limiting step in de novo sphingolipid biosynthesis. Hepatic ceramide accumulation was further confirmed by mass spectrometry-based lipidomics. Taken together, our results revealed that AHR activation results in the up-regulation of Sptlc2, leading to ceramide accumulation, thus promoting lipogenesis, which can induce hepatic lipid accumulation.
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Affiliation(s)
- Qing Liu
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Limin Zhang
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS), Wuhan, 430071, China
| | - Erik L Allman
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Troy D Hubbard
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Iain A Murray
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Fuhua Hao
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Yuan Tian
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Wei Gui
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Robert G Nichols
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Philip B Smith
- Huck Institutes of the Life Sciences, University Park, PA, 16802, USA
| | - Mallappa Anitha
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Gary H Perdew
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Andrew D Patterson
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
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22
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van den Bogaard EH, Esser C, Perdew GH. The aryl hydrocarbon receptor at the forefront of host-microbe interactions in the skin: A perspective on current knowledge gaps and directions for future research and therapeutic applications. Exp Dermatol 2021; 30:1477-1483. [PMID: 34105853 PMCID: PMC8518783 DOI: 10.1111/exd.14409] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/11/2021] [Accepted: 05/22/2021] [Indexed: 02/06/2023]
Abstract
The skin is home to a community of skin microbiota including bacteria, viruses and fungi, which are widely accepted to be of importance for skin homeostasis but also associated with skin diseases. Detailed knowledge on the skin microbiota composition and its changes in a number of skin diseases is available. Yet, specific interactions between microbes and the host skin cells or how they communicate with each other are less well understood. To identify, understand and eventually therapeutically exploit causal relationships of microbial dysbiosis with disease, studies are required that address the receptors and mediators involved in host‐microbe interactions. In this perspective article, we provide an outlook on one of such receptors, namely the aryl hydrocarbon receptor (AHR). The AHR is well known for being a ligand‐activated transcription factor regulating the proliferation, differentiation and function of many cell types present in the skin. Its targeting by anti‐inflammatory therapeutics such as coal tar and Tapinarof is effective in atopic dermatitis and psoriasis. AHR signalling is activated upon binding of wide variety of small chemicals or ligands, including microbiota‐derived metabolites. New evidence has emerged pointing towards a key role for epidermal AHR signalling through skin microbiota‐derived metabolites. In response, AHR‐driven expression of antimicrobial peptides and stratum corneum formation may alter the skin microbiota composition. This a self‐perpetuating feedback loop calls for novel therapeutic intervention strategies for which we herein discuss the requirements in future mechanistic studies.
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Affiliation(s)
- Ellen H van den Bogaard
- Department of Dermatology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Charlotte Esser
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
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23
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van den Bogaard EH, Perdew GH. The Enigma of AHR Activation in the Skin: Interplay among Ligands, Metabolism, and Bioavailability. J Invest Dermatol 2021; 141:1385-1388. [PMID: 34024340 DOI: 10.1016/j.jid.2020.12.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 01/29/2023]
Abstract
AHR is expressed in a variety of skin cell types and contributes to skin homeostasis. Therapeutic targeting of AHR in dermatology was first described for the treatment of inflammatory skin diseases using coal tar ointment. In addition to therapies involving active ligands such as coal tar and tapinarof, the inhibition of AHR-dependent enzymatic activities in the skin may be an alternative approach to resolving skin inflammation.
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Affiliation(s)
- Ellen H van den Bogaard
- Laboratory for Experimental Dermatology, Department of Dermatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Gary H Perdew
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
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24
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Murray IA, Perdew GH. How Ah Receptor Ligand Specificity Became Important in Understanding Its Physiological Function. Int J Mol Sci 2020; 21:ijms21249614. [PMID: 33348604 PMCID: PMC7766308 DOI: 10.3390/ijms21249614] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/11/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
Increasingly, the aryl hydrocarbon receptor (AHR) is being recognized as a sensor for endogenous and pseudo-endogenous metabolites, and in particular microbiota and host generated tryptophan metabolites. One proposed explanation for this is the role of the AHR in innate immune signaling within barrier tissues in response to the presence of microorganisms. A number of cytokine/chemokine genes exhibit a combinatorial increase in transcription upon toll-like receptors and AHR activation, supporting this concept. The AHR also plays a role in the enhanced differentiation of intestinal and dermal epithelium leading to improved barrier function. Importantly, from an evolutionary perspective many of these tryptophan metabolites exhibit greater activation potential for the human AHR when compared to the rodent AHR. These observations underscore the importance of the AHR in barrier tissues and may lead to pharmacologic therapeutic intervention.
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25
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Dong F, Hao F, Murray IA, Smith PB, Koo I, Tindall AM, Kris-Etherton PM, Gowda K, Amin SG, Patterson AD, Perdew GH. Intestinal microbiota-derived tryptophan metabolites are predictive of Ah receptor activity. Gut Microbes 2020; 12:1-24. [PMID: 32783770 PMCID: PMC7524359 DOI: 10.1080/19490976.2020.1788899] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Commensal microbiota-dependent tryptophan catabolism within the gastrointestinal tract is known to exert profound effects upon host physiology, including the maintenance of epithelial barrier and immune function. A number of abundant microbiota-derived tryptophan metabolites exhibit activation potential for the aryl hydrocarbon receptor (AHR). Gene expression facilitated by AHR activation through the presence of dietary or microbiota-generated metabolites can influence gastrointestinal homeostasis and confer protection from intestinal challenges. Utilizing untargeted mass spectrometry-based metabolomics profiling, combined with AHR activity screening assays, we identify four previously unrecognized tryptophan metabolites, present in mouse cecal contents and human stool, with the capacity to activate AHR. Using GC/MS and LC/MS platforms, quantification of these novel AHR activators, along with previously established AHR-activating tryptophan metabolites, was achieved, providing a relative order of abundance. Using physiologically relevant concentrations and quantitative gene expression analyses, the relative efficacy of these tryptophan metabolites with regard to mouse or human AHR activation potential is examined. These data reveal indole, 2-oxindole, indole-3-acetic acid and kynurenic acid as the dominant AHR activators in mouse cecal contents and human stool from participants on a controlled diet. Here we provide the first documentation of the relative abundance and AHR activation potential of a panel of microbiota-derived tryptophan metabolites. Furthermore, these data reveal the human AHR to be more sensitive, at physiologically relevant concentrations, to tryptophan metabolite activation than mouse AHR. Additionally, correlation analyses indicate a relationship linking major tryptophan metabolite abundance with AHR activity, suggesting these cecal/fecal metabolites represent biomarkers of intestinal AHR activity.
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Affiliation(s)
- Fangcong Dong
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Fuhua Hao
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Iain A. Murray
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Philip B. Smith
- The Huck Institutes of the Life Sciences, the Pennsylvania State University, University Park, PA, USA
| | - Imhoi Koo
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Alyssa M. Tindall
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Penny M. Kris-Etherton
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Krishne Gowda
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA
| | - Shantu G. Amin
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA,CONTACT Gary H. Perdew Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
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26
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Abstract
Increasing evidence suggests a significant role for microbiota dependent metabolites and co-metabolites, acting as aryl hydrocarbon receptor (AHR) ligands, to facilitate bidirectional communication between the host and the microbiota and thus modulate physiology. Such communication is particularly evident within the gastrointestinal tract. Through binding to or activating the AHR, these metabolites play fundamental roles in various physiological processes and likely contribute to the maintenance of intestinal homeostasis. In recent years, tryptophan metabolites were screened to identify physiologically relevant AHR ligands or activators. The discovery of specific microbiota-derived indole-based metabolites as AHR ligands may provide insight concerning how these metabolites affect interactions between gut microbiota and host intestinal homeostasis and how this relates to chronic GI disease and overall health. A greater understanding of the mechanisms that modulate the production of such metabolites and associated AHR activity may be utilized to effectively treat inflammatory diseases and promote human health. Here, we review microbiota-derived AHR ligands generated from tryptophan that modulate host-gut microbiota interactions and discuss possible intervention strategies for potential therapies in the future.
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Affiliation(s)
- Fangcong Dong
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA,CONTACT Gary H. Perdew The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA16802, USA
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27
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Dvořák Z, Kopp F, Costello CM, Kemp JS, Li H, Vrzalová A, Štěpánková M, Bartoňková I, Jiskrová E, Poulíková K, Vyhlídalová B, Nordstroem LU, Karunaratne CV, Ranhotra HS, Mun KS, Naren AP, Murray IA, Perdew GH, Brtko J, Toporova L, Schön A, Wallace BD, Walton WG, Redinbo MR, Sun K, Beck A, Kortagere S, Neary MC, Chandran A, Vishveshwara S, Cavalluzzi MM, Lentini G, Cui JY, Gu H, March JC, Chatterjee S, Matson A, Wright D, Flannigan KL, Hirota SA, Sartor RB, Mani S. Targeting the pregnane X receptor using microbial metabolite mimicry. EMBO Mol Med 2020; 12:e11621. [PMID: 32153125 PMCID: PMC7136958 DOI: 10.15252/emmm.201911621] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 12/18/2022] Open
Abstract
The human PXR (pregnane X receptor), a master regulator of drug metabolism, has essential roles in intestinal homeostasis and abrogating inflammation. Existing PXR ligands have substantial off-target toxicity. Based on prior work that established microbial (indole) metabolites as PXR ligands, we proposed microbial metabolite mimicry as a novel strategy for drug discovery that allows exploiting previously unexplored parts of chemical space. Here, we report functionalized indole derivatives as first-in-class non-cytotoxic PXR agonists as a proof of concept for microbial metabolite mimicry. The lead compound, FKK6 (Felix Kopp Kortagere 6), binds directly to PXR protein in solution, induces PXR-specific target gene expression in cells, human organoids, and mice. FKK6 significantly represses pro-inflammatory cytokine production cells and abrogates inflammation in mice expressing the human PXR gene. The development of FKK6 demonstrates for the first time that microbial metabolite mimicry is a viable strategy for drug discovery and opens the door to underexploited regions of chemical space.
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28
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Gourronc FA, Perdew GH, Robertson LW, Klingelhutz AJ. PCB126 blocks the thermogenic beiging response of adipocytes. Environ Sci Pollut Res Int 2020; 27:8897-8904. [PMID: 31721030 PMCID: PMC7098842 DOI: 10.1007/s11356-019-06663-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 10/01/2019] [Indexed: 05/16/2023]
Abstract
Subcutaneous white adipose tissue is capable of becoming thermogenic in a process that is referred to as "beiging." Beiging is associated with activation of the uncoupling protein, UCP1, and is known to be important for preventing adipose hypertrophy and development of insulin resistance. Polychlorinated biphenyls (PCBs) accumulate in fat, and it is hypothesized that disruption of adipogenesis and adipocyte function by PCBs may be causative in the development of obesity and diabetes. We developed immortal human subcutaneous preadipocytes that, when differentiated, are capable of beiging. Preadipocytes that were treated with polychlorinated biphenyl congener 126 (PCB126), followed by differentiation, were suppressed for their ability to activate UCP1 upon β-adrenergic stimulation with norepinephrine (NE), demonstrating a block in the beiging response. Treatment of preadipocytes with another known endogenous AhR agonist, indoxyl sulfate (IS), followed by differentiation also blocked the NE-stimulated upregulation of UCP1. Knockdown of the aryl hydrocarbon receptor (AhR) caused the preadipocytes to be refractory to PCB126 and IS effects. The chemical AhR antagonist, CH223191, was effective at preventing the effects of PCB126 but not IS, indicating AhR ligand specificity of CH223191. Repression of NE-induced UCP1 upregulation was also observed when already-differentiated mature adipocytes were treated with PCB126 but not IS. These results indicate that exposure of preadipocytes to endogenous (IS) or exogenous (PCB126) AhR agonists is effective at blocking them from becoming functional adipocytes that are capable of the beiging response. Mature adipocytes may have differential responses. This finding suggests a mechanism by which dioxin-like PCBs such as PCB126 could lead to disruption in energy homeostasis, potentially leading to obesity and diabetes.
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Affiliation(s)
- Francoise A Gourronc
- Department of Microbiology and Immunology, University of Iowa, 3-612 BSB, 51 Newton Road, Iowa City, IA, 52242, USA
| | - Gary H Perdew
- Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, 16802, PA, USA
| | - Larry W Robertson
- Department of Occupational & Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Aloysius J Klingelhutz
- Department of Microbiology and Immunology, University of Iowa, 3-612 BSB, 51 Newton Road, Iowa City, IA, 52242, USA.
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29
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Abstract
An explosion of knowledge on the molecular and cellular mechanisms that mediate carcinogenesis has occurred in recent years. Although cancer has existed for over a million years in the human species, effective cures for most cancers that target molecular and cellular pathways have not been achieved. Multiple cellular targets have been examined for preventing or treating cancers including, but not limited to, transcription factors, kinase-mediated cell signaling pathways, and more recently epigenetic targeting of oncogenes and tumor suppressors, and immunomodulation such as chimeric antigen receptor-T cells. Even as the state of knowledge of cancer mechanisms increases, there is considerable room for improvement in preventing and treating cancers. Understanding how a normal cell is transformed into a cancer cell is known but there is considerable tissue and cell type specificity. This has given rise to the field of precision medicine as applied to cancer therapy. Thus, while the development of preventive and treatment regimens has increased, there are certain obstacles that need to be overcome in order to decrease cancer incidence and increase survival of cancer patients. The purpose of this review is to summarize the advances made in cancer biology and how these advances have been used to develop, and hinder, preventive, and therapeutic strategies for cancer.
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Affiliation(s)
- Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland 20892
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jeffrey M Peters
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
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30
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Tian Y, Gui W, Smith PB, Koo I, Murray IA, Cantorna MT, Perdew GH, Patterson AD. Isolation and Identification of Aryl Hydrocarbon Receptor Modulators in White Button Mushrooms ( Agaricus bisporus). J Agric Food Chem 2019; 67:9286-9294. [PMID: 31339733 PMCID: PMC7896426 DOI: 10.1021/acs.jafc.9b03212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Natural aryl hydrocarbon (AHR) ligands have been identified in food and herbal medicines, and they may exhibit beneficial activity in humans. In this study, white button (WB) feeding significantly decreased AHR target gene expression in the small intestine of both conventional and germ-free mice. High-performance liquid chromatography (HPLC) fractionation and ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) combined with an AHR-responsive cell-based luciferase gene reporter assay were used to isolate and characterize benzothiazole (BT) derivatives and 6-methylisoquinoline (6-MIQ) as AHR modulators from WB mushrooms. The study showed dose-dependent changes of AHR transformation determined by the cell-based luciferase gene reporter assay and transcription of CYP1A1 in human Caco-2 cells by BT derivatives and 6-MIQ. These findings suggested that WB mushroom contains new classes of natural AHR modulators and demonstrated HPLC fractionation and UHPLC-MS/MS combined with a cell-based luciferase gene reporter assay as a useful approach for isolation and characterization of the previously unidentifed AHR modulators from natural products.
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Affiliation(s)
- Yuan Tian
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, University of Chinese Academy of Sciences, Wuhan, 430071, P. R. China
| | - Wei Gui
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Philip B. Smith
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Imhoi Koo
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Iain A. Murray
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Margherita T. Cantorna
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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31
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Muku GE, Murray IA, Perdew GH. Activation of the Ah Receptor Modulates Gastrointestinal Homeostasis and the Intestinal Microbiome. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s40495-019-00197-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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32
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Muku GE, Blazanin N, Dong F, Smith PB, Thiboutot D, Gowda K, Amin S, Murray IA, Perdew GH. Selective Ah receptor ligands mediate enhanced SREBP1 proteolysis to restrict lipogenesis in sebocytes. Toxicol Sci 2019; 171:146-158. [PMID: 31225620 PMCID: PMC6736396 DOI: 10.1093/toxsci/kfz140] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 12/12/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) mediates 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) induced toxicity that can lead to chloracne in humans. A characteristic of chloracne, in contrast to acne vulgaris, is shrinkage or loss of sebaceous glands. Acne vulgaris, on the other hand, is often accompanied by excessive sebum production. Here, we examined the role of AHR in lipid synthesis in human sebocytes using distinct classes of AHR ligands. Modulation of AHR activity attenuated the expression of lipogenic genes and key pro-inflammatory markers in the absence of canonical DRE-driven transcription of the AHR target gene CYP1A1. Furthermore, topical treatment with TCDD, which mediates DRE-dependent activity, and SGA360, which fails to induce DRE-mediated responses, both exhibited a decrease in the size of sebaceous glands and the number of sebocytes within each gland in the skin. To elucidate the mechanism of AHR-mediated repression of lipid synthesis, we demonstrated that selective AHR modulators, SGA360 and SGA315 increased the protein turnover of the mature sterol regulatory element-binding protein (mSREBP-1), the principal transcriptional regulator of the fatty acid synthesis pathway. Interestingly, selective AHR ligand treatment significantly activated the AMPK-dependent kinase (AMPK) in sebocytes. Moreover, we demonstrated an inverse correlation between the active AMPK and the mSREBP-1 protein, which is consistent with the previously reported role of AMPK in inhibiting cleavage of SREBP-1. Overall, our findings indicate a DRE-independent function of selective AHR ligands in modulating lipid synthesis in human sebocytes, which might raise the possibility of using AHR as a therapeutic target for treatment of acne.
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Affiliation(s)
- Gulsum E Muku
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Nicholas Blazanin
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Fangcong Dong
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Philip B Smith
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Diane Thiboutot
- Department of Dermatology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Krishne Gowda
- Department of Pharmacology or Penn State College of Medicine, Hershey, Pennsylvania
| | - Shantu Amin
- Department of Pharmacology or Penn State College of Medicine, Hershey, Pennsylvania
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
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Hubbard TD, Liu Q, Murray IA, Dong F, Miller C, Smith PB, Gowda K, Lin JM, Amin S, Patterson AD, Perdew GH. Microbiota Metabolism Promotes Synthesis of the Human Ah Receptor Agonist 2,8-Dihydroxyquinoline. J Proteome Res 2019; 18:1715-1724. [PMID: 30777439 DOI: 10.1021/acs.jproteome.8b00946] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The aryl hydrocarbon receptor (AHR) is a major regulator of immune function within the gastrointestinal tract. Resident microbiota are capable of influencing AHR-dependent signaling pathways via production of an array of bioactive molecules that act as AHR agonists, such as indole or indole-3-aldehyde. Bacteria produce a number of quinoline derivatives, of which some function as quorum-sensing molecules. Thus, we screened relevant hydroxyquinoline derivatives for AHR activity using AHR responsive reporter cell lines. 2,8-Dihydroxyquinoline (2,8-DHQ) was identified as a species-specific AHR agonist that exhibits full AHR agonist activity in human cell lines, but only induces modest AHR activity in mouse cells. Additional dihydroxylated quinolines tested failed to activate the human AHR. Nanomolar concentrations of 2,8-DHQ significantly induced CYP1A1 expression and, upon cotreatment with cytokines, synergistically induced IL6 expression. Ligand binding competition studies subsequently confirmed 2,8-DHQ to be a human AHR ligand. Several dihydroxyquinolines were detected in human fecal samples, with concentrations of 2,8-DHQ ranging between 0 and 3.4 pmol/mg feces. Additionally, in mice the microbiota was necessary for the presence of DHQ in cecal contents. These results suggest that microbiota-derived 2,8-DHQ would contribute to AHR activation in the human gut, and thus participate in the protective and homeostatic effects observed with gastrointestinal AHR activation.
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Affiliation(s)
| | | | | | | | - Charles Miller
- Department of Global Environmental Health Sciences , Tulane University School of Public Health and Tropical Medicine , New Orleans , Louisiana 70112 , United States
| | | | - Krishne Gowda
- Department of Pharmacology , Penn State College of Medicine , Hershey , Pennsylvania 17033 , United States
| | - Jyh Ming Lin
- Department of Biochemistry and Molecular Biology , Penn State College of Medicine , Hershey , Pennsylvania 17033 , United States
| | - Shantu Amin
- Department of Pharmacology , Penn State College of Medicine , Hershey , Pennsylvania 17033 , United States
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Esser C, Lawrence BP, Sherr DH, Perdew GH, Puga A, Barouki R, Coumoul X. Old Receptor, New Tricks-The Ever-Expanding Universe of Aryl Hydrocarbon Receptor Functions. Report from the 4th AHR Meeting, 29⁻31 August 2018 in Paris, France. Int J Mol Sci 2018; 19:ijms19113603. [PMID: 30445691 PMCID: PMC6274973 DOI: 10.3390/ijms19113603] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 11/09/2018] [Accepted: 11/10/2018] [Indexed: 01/11/2023] Open
Abstract
In a time where "translational" science has become a mantra in the biomedical field, it is reassuring when years of research into a biological phenomenon suddenly points towards novel prevention or therapeutic approaches to disease, thereby demonstrating once again that basic science and translational science are intimately linked. The studies on the aryl hydrocarbon receptor (AHR) discussed here provide a perfect example of how years of basic toxicological research on a molecule, whose normal physiological function remained a mystery for so long, has now yielded a treasure trove of actionable information on the development of targeted therapeutics. Examples are autoimmunity, metabolic imbalance, inflammatory skin and gastro-intestinal diseases, cancer, development and perhaps ageing. Indeed, the AHR field no longer asks, "What does this receptor do in the absence of xenobiotics?" It now asks, "What doesn't this receptor do?".
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Affiliation(s)
- Charlotte Esser
- IUF-Leibniz Research Institute for Environmental Medicine, Auf´m Hennekamp 50, 40225 Düsseldorf, Germany.
| | - B Paige Lawrence
- Environmental Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA.
| | - David H Sherr
- Department of Environmental Health, Boston University School of Public Health, 72 East Concord Street, Boston, MA 02118, USA.
| | - Gary H Perdew
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Alvaro Puga
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
| | - Robert Barouki
- Toxicologie Pharmacologie et Signalisation Cellulaire, INSERM UMR-S1124, 45 rue des Saints-Pères, 75006 Paris, France.
- UFR des Sciences Fondamentales et Biomédicales, Université Paris Descartes, 45 rue des Saints-Pères, Sorbonne Paris Cité, 75006 Paris, France.
| | - Xavier Coumoul
- Toxicologie Pharmacologie et Signalisation Cellulaire, INSERM UMR-S1124, 45 rue des Saints-Pères, 75006 Paris, France.
- UFR des Sciences Fondamentales et Biomédicales, Université Paris Descartes, 45 rue des Saints-Pères, Sorbonne Paris Cité, 75006 Paris, France.
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35
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Kumar MB, Perdew GH. Nuclear receptor coactivator SRC-1 interacts with the Q-rich subdomain of the AhR and modulates its transactivation potential. Gene Expr 2018; 8:273-86. [PMID: 10947077 PMCID: PMC6157383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The aryl hydrocarbon receptor (AhR), a soluble cytosolic protein, mediates many of the toxic effects of TCDD and related chemicals. The toxic effects are largely cell, tissue, and promoter context dependent. Although many details of the overall dioxin signal transduction have been elucidated, the transcriptional regulation of dioxin-induced genes like cyp1A1 is not yet completely understood. Previously, we have shown that the co-regulator RIP140 is a potential AhR coactivator. In this report, the role of coactivator, SRC-1, in AhR-mediated transcriptional regulation was examined. SRC-1 increased AhR-mediated, TCDD-dependent reporter gene activity three-fold in Hepa-1 and COS-1 cells. In in vitro interaction assays, SRC-1 was found to interact with AhR but not with ARNT. SRC-1 interacted weakly with AhR in the absence of TCDD and the addition of ligand further increased SRC-1 binding to AhR. Deletional mapping studies of the AhR revealed that SRC-1 binds to the AhR transactivation domain. Finer mapping of the SRC-1-interacting subdomains in the AhR transactivation domain suggested that the Q-rich subdomain was necessary and sufficient for interaction, similar to that seen with RIP140. Using GFP-tagged constructs, SRC-1 was shown to interact with AhR in cells. Unlike RIP140, LXXLL motifs in SRC-1 were necessary for interaction with AhR in vitro and for coactivation in Hepa-1 cells. The recruitment of certain coactivators by a variety of receptors suggests possible common coactivator pools and competition among receptors for limiting coactivators. Examination of the role of SRC-1 in AhR/ARNT transactivation in ARNT-deficient mutant Hepa-1 c4 cells demonstrates that the AhR transactivation domain is sufficient for enhanced coactivation mediated by SRC-1 in the presence of a transactivation domain deleted ARNT protein.
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Affiliation(s)
- Mohan B. Kumar
- *Graduate Program in Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Gary H. Perdew
- *Graduate Program in Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
- †Center for Molecular Toxicology and the Department of Veterinary Science, The Pennsylvania State University, University Park, PA 16802
- Address correspondence to Gary H. Perdew, Department of Veterinary Science, 115 Henning Building, University Park, PA 16802. Tel: (814) 865-0400; (814) 863-6140; E-mail:
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36
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Nichols RG, Cai J, Murray IA, Koo I, Smith PB, Perdew GH, Patterson AD. Structural and Functional Analysis of the Gut Microbiome for Toxicologists. ACTA ACUST UNITED AC 2018; 78:e54. [PMID: 30230220 DOI: 10.1002/cptx.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Characterizing the reciprocal interactions between toxicants, the gut microbiota, and the host, holds great promise for improving our mechanistic understanding of toxic endpoints. Advances in culture-independent sequencing analysis (e.g., 16S rRNA gene amplicon sequencing) combined with quantitative metabolite profiling (i.e., metabolomics) have provided new ways of studying the gut microbiome and have begun to illuminate how toxicants influence the structure and function of the gut microbiome. Developing a standardized protocol is important for establishing robust, reproducible, and importantly, comparative data. This protocol can be used as a foundation for examining the gut microbiome via sequencing-based analysis and metabolomics. Two main units follow: (1) analysis of the gut microbiome via sequencing-based approaches; and (2) functional analysis of the gut microbiome via metabolomics. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Robert G Nichols
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Jingwei Cai
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Iain A Murray
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Imhoi Koo
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Philip B Smith
- Metabolomics, The Pennsylvania State University, University Park, Pennsylvania
| | - Gary H Perdew
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Andrew D Patterson
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
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37
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Belton K, Tian Y, Zhang L, Anitha M, Smith PB, Perdew GH, Patterson AD. Metabolomics Reveals Aryl Hydrocarbon Receptor Activation Induces Liver and Mammary Gland Metabolic Dysfunction in Lactating Mice. J Proteome Res 2018; 17:1375-1382. [PMID: 29521512 PMCID: PMC5898790 DOI: 10.1021/acs.jproteome.7b00709] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Indexed: 01/28/2023]
Abstract
The liver and the mammary gland have complementary metabolic roles during lactation. Substrates synthesized by the liver are released into the circulation and are taken up by the mammary gland for milk production. The aryl hydrocarbon receptor (AHR) has been identified as a lactation regulator in mice, and its activation has been associated with myriad morphological, molecular, and functional defects such as stunted gland development, decreased milk production, and changes in gene expression. In this study, we identified adverse metabolic changes in the lactation network (mammary, liver, and serum) associated with AHR activation using 1H nuclear magnetic resonance (NMR)-based metabolomics. Pregnant mice expressing Ahr d (low affinity) or Ahr b (high affinity) were fed diets containing beta naphthoflavone (BNF), a potent AHR agonist. Mammary, serum, and liver metabolomics analysis identified significant changes in lipid and TCA cycle intermediates in the Ahr b mice. We observed decreased amino acid and glucose levels in the mammary gland extracts of Ahr b mice fed BNF. The serum of BNF fed Ahr b mice had significant changes in LDL/VLDL (increased) and HDL, PC, and GPC (decreased). Quantitative PCR analysis revealed ∼50% reduction in the expression of key lactogenesis mammary genes including whey acid protein, α-lactalbumin, and β-casein. We also observed morphologic and developmental disruptions in the mammary gland that are consistent with previous reports. Our observations support that AHR activity contributes to metabolism regulation in the lactation network.
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Affiliation(s)
- Kerry
R. Belton
- Department
of Veterinary and Biomedical Sciences, Center
for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yuan Tian
- Department
of Veterinary and Biomedical Sciences, Center
for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- CAS Key Laboratory of Magnetic Resonance in Biological
Systems, State Key Laboratory of Magnetic Resonance and Atomic and
Molecular Physics, National Centre for Magnetic Resonance in Wuhan,
Wuhan Institute of Physics and Mathematics, University of Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Limin Zhang
- Department
of Veterinary and Biomedical Sciences, Center
for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- CAS Key Laboratory of Magnetic Resonance in Biological
Systems, State Key Laboratory of Magnetic Resonance and Atomic and
Molecular Physics, National Centre for Magnetic Resonance in Wuhan,
Wuhan Institute of Physics and Mathematics, University of Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Mallappa Anitha
- Department
of Veterinary and Biomedical Sciences, Center
for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Philip B. Smith
- Metabolomics
Facility, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Gary H. Perdew
- Department
of Veterinary and Biomedical Sciences, Center
for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Andrew D. Patterson
- Department
of Veterinary and Biomedical Sciences, Center
for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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38
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Organtini KL, Hubbard TD, Perdew GH, Dorman FL. Assessment of Ah receptor transcriptional activity mediated by halogenated dibenzo-p-dioxins and dibenzofurans (PXDD/Fs) in human and mouse cell systems. J Environ Sci Health A Tox Hazard Subst Environ Eng 2017; 52:1295-1302. [PMID: 28922086 DOI: 10.1080/10934529.2017.1362290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polybrominated and mixed bromo/chloro dibenzo-p-dioxins and dibenzofurans (PXDD/Fs) are emerging environmental contaminants of concern. Thus far, an understanding of the toxicological behavior of these chemical species and their impact upon human health is incomplete. Here we utilized human and mouse hepatocellular carcinoma cell lines to examine the ability of differentially halogenated PXDD/F congeners to induce aryl hydrocarbon receptor (AHR)-mediated transcriptional activity. Dose-response experiments in reporter cell lines identified varied potencies among differentially halogenated PXDD/F isomers by comparison of EC50 values relative to the prototypical AHR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Brominated PXDD/F species displayed reduced capacity to activate the mouse AHR, compared to TCDD. Only BrCl3 dibenzo-p-dioxin was found to have a greater relative potency than TCDD to induce human AHR transcriptional activity. Human cells required ∼10-29-fold higher ligand concentrations to induce analogous AHR activity, relative to mouse cells. Decreased sensitivity of the human AHR to brominated dibenzofuran congeners directly corresponded to the number of bromine functional groups. Mixtures of these compounds exhibited an additive effect on AHR activation. The data also support the inclusion of mixed halogenated dibenzo-p-dioxins and dibenzofurans into routine environmental screening procedures as well as more thorough toxicological characterization of PXDD/Fs.
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Affiliation(s)
- Kari L Organtini
- a Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania , USA
| | - Troy D Hubbard
- a Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania , USA
| | - Gary H Perdew
- a Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania , USA
| | - Frank L Dorman
- a Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania , USA
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Smith KJ, Murray IA, Boyer JA, Perdew GH. Allelic variants of the aryl hydrocarbon receptor differentially influence UVB-mediated skin inflammatory responses in SKH1 mice. Toxicology 2017; 394:27-34. [PMID: 29197551 DOI: 10.1016/j.tox.2017.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/07/2017] [Accepted: 11/28/2017] [Indexed: 10/18/2022]
Abstract
The mouse strain SKH1 is widely used in skin research due to its hairless phenotype and intact immune system. Due to the complex nature of aryl hydrocarbon receptor (AHR) function in the skin, the development of additional in vivo models is necessary to study its role in cutaneous homeostasis and pathology. Variants of the Ah allele, exist among different mouse strains. The Ahb-1 and Ahd alleles express high and low affinity ligand binding forms of the AHR, respectively. The outbred SKH1 mice express the Ahb-2 and/or Ahd alleles. SKH1 mice were crossed with C57BL/6J mice, which harbor the Ahb-1 allele, to create useful models for studying endogenous AHR function. SKH1 mice were bred to be homozygous for either the Ahb-1 or Ahd allele to establish strains for use in comparative studies of the effects of differential ligand-mediated activation through gene expression changes upon UVB exposure. Ahb-1 or Ahd allelic status was confirmed by DNA sequence analysis. We tested the hypothesis that SKH1-Ahb-1 mice would display enhanced inflammatory signaling upon UVB exposure compared to SKH1-Ahd mice. Differential basal AHR activation between the strains was determined by assessing Cyp1a1 expression levels in the small intestine, liver, and skin of the SKH1-Ahb-1 mice compared to SKH1-Ahd mice. To determine whether SKH1-Ahb-1 mice are more prone to a pro-inflammatory phenotype in response to UVB, gene expression of inflammatory mediators was analyzed. SKH1-Ahb-1 mice expressed enhanced gene expression of the chemotactic factors Cxcl5, Cxcl1, and Ccl20, as well as the inflammatory signaling factors S100a9 and Ptgs2, compared to SKH1-Ahd mice in skin. These data supports a role for AHR activation and enhanced inflammatory signaling in skin.
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Affiliation(s)
- Kayla J Smith
- The Graduate Program in Biochemistry, Microbiology, and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University,University Park, PA 16802, United States; Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University,University Park, PA 16802, United States
| | - Jacob A Boyer
- Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University,University Park, PA 16802, United States
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University,University Park, PA 16802, United States; Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University,University Park, PA 16802, United States.
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40
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Smith KJ, Boyer JA, Muku GE, Murray IA, Gowda K, Desai D, Amin SG, Glick AB, Perdew GH. Editor's Highlight: Ah Receptor Activation Potentiates Neutrophil Chemoattractant (C-X-C Motif) Ligand 5 Expression in Keratinocytes and Skin. Toxicol Sci 2017; 160:83-94. [PMID: 28973351 PMCID: PMC5837612 DOI: 10.1093/toxsci/kfx160] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Chemokines are components of the skin microenvironment, which enable immune cell chemotaxis. Traditionally, transcription factors involved in inflammatory signaling (eg, NFκB) are important mediators of chemokine expression. To what extent xenobiotics and their associated receptors control chemokine expression is poorly understood. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor known to mediate physiological responses in the skin through the regulation of genes involved in xenobiotic metabolism, epidermal differentiation, and immunity. Here, we demonstrate that AHR activation within primary mouse keratinocytes regulates the expression of a neutrophil directing chemokine (C-X-C motif) ligand 5 (Cxcl5). AHR-mediated regulation of Cxcl5 is because of direct transcriptional activity upon treatment with AHR agonists such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Additionally, AHR mediates enhanced induction of Cxcl5 upon exposure to an agonist and the inflammatory cytokine interleukin 1 beta. This synergy is confined primarily to keratinocytes, as dermal fibroblasts did not achieve the same level of combinatorial induction. AHR-specific antagonists were able to reduce basal and induced levels of Cxcl5, demonstrating the potential for pharmacological intervention. Exposure of C57BL/6 J mice to ultraviolet (UV) light followed by topical treatment with the AHR agonist formylindolo(3,2-b)carbazole (FICZ) significantly induced Cxcl5 expression in skin compared with UV alone, and this response was absent in Ahr-/- mice. These results establish AHR as an important mediator of Cxcl5, with implications for the treatment of inflammatory skin diseases.
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Affiliation(s)
- Kayla J. Smith
- The Graduate Program in Biochemistry, Microbiology, and Molecular Biology, Department of Biochemistry and Molecular Biology
| | - Jacob A. Boyer
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gulsum E. Muku
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Iain A. Murray
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Krishne Gowda
- Department of Pharmacology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - Dhimant Desai
- Department of Pharmacology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - Shantu G. Amin
- Department of Pharmacology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - Adam B. Glick
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
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Hubbard TD, Murray IA, Nichols RG, Cassel K, Podolsky M, Kuzu G, Tian Y, Smith P, Kennett MJ, Patterson AD, Perdew GH. Dietary Broccoli Impacts Microbial Community Structure and Attenuates Chemically Induced Colitis in Mice in an Ah receptor dependent manner. J Funct Foods 2017; 37:685-698. [PMID: 29242716 PMCID: PMC5726276 DOI: 10.1016/j.jff.2017.08.038] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Consumption of broccoli mediates numerous chemo-protective benefits through the intake of phytochemicals, some of which modulate aryl hydrocarbon receptor (AHR) activity. Whether AHR activation is a critical aspect of the therapeutic potential of dietary broccoli is not known. Here we administered isocaloric diets, with or without supplementation of whole broccoli (15% w/w), to congenic mice expressing the high-affinity Ahrb/b or low-affinity Ahrd/d alleles, for 24 days and examined the effects on AHR activity, intestinal microbial community structure, inflammatory status, and response to chemically induced colitis. Cecal microbial community structure and metabolic potential were segregated according to host dietary and AHR status. Dietary broccoli associated with heightened intestinal AHR activity, decreased microbial abundance of the family Erysipelotrichaceae, and attenuation of colitis. In summary, broccoli consumption elicited an enhanced response in ligand-sensitive Ahrb/b mice, demonstrating that in part the beneficial aspects of dietary broccoli upon intestinal health are associated with heightened AHR activity.
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Affiliation(s)
- Troy D. Hubbard
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Iain A. Murray
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Robert G. Nichols
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Kaitlyn Cassel
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Michael Podolsky
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Guray Kuzu
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Yuan Tian
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Phillip Smith
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Mary J. Kennett
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
| | - Gary H. Perdew
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802
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Abstract
The Ah receptor (AHR) is capable of binding a structurally diverse group of compounds that can be found in the diet, produced by bacteria in the gut and through endogenous metabolism. The gastrointestinal tract is a rich source of AHR ligands, which have been shown to protect the gut upon challenge with either pathogenic bacteria or toxic chemicals. The human AHR can be activated by a broader range of ligands compared to the mouse AHR, suggesting that studies in mice may underestimate the impact of AHR ligands in the human gut. The protective effect of AHR activation appears to be due to modulating the immune system within the gut. While several mechanisms have been established, due to the increasingly pleotropic nature of the AHR, other mechanisms of action likely exist that remain to be identified. The major contributors to AHR function in the gut and the most appropriate level of receptor activation that maintains intestinal homeostasis warrants further investigation.
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Affiliation(s)
- Iain A Murray
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA 16802
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, and Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, PA 16802
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43
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Koga T, Yao PL, Goudarzi M, Murray IA, Balandaram G, Gonzalez FJ, Perdew GH, Fornace AJ, Peters JM. Regulation of Cytochrome P450 2B10 (CYP2B10) Expression in Liver by Peroxisome Proliferator-activated Receptor-β/δ Modulation of SP1 Promoter Occupancy. J Biol Chem 2016; 291:25255-25263. [PMID: 27765815 DOI: 10.1074/jbc.m116.755447] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/13/2016] [Indexed: 01/12/2023] Open
Abstract
Alcoholic liver disease is a pathological condition caused by overconsumption of alcohol. Because of the high morbidity and mortality associated with this disease, there remains a need to elucidate the molecular mechanisms underlying its etiology and to develop new treatments. Because peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) modulates ethanol-induced hepatic effects, the present study examined alterations in gene expression that may contribute to this disease. Chronic ethanol treatment causes increased hepatic CYP2B10 expression inPparβ/δ+/+ mice but not in Pparβ/δ-/- mice. Nuclear and cytosolic localization of the constitutive androstane receptor (CAR), a transcription factor known to regulate Cyp2b10 expression, was not different between genotypes. PPARγ co-activator 1α, a co-activator of both CAR and PPARβ/δ, was up-regulated in Pparβ/δ+/+ liver following ethanol exposure, but not in Pparβ/δ-/- liver. Functional mapping of the Cyp2b10 promoter and ChIP assays revealed that PPARβ/δ-dependent modulation of SP1 promoter occupancy up-regulated Cyp2b10 expression in response to ethanol. These results suggest that PPARβ/δ regulates Cyp2b10 expression indirectly by modulating SP1 and PPARγ co-activator 1α expression and/or activity independent of CAR activity. Ligand activation of PPARβ/δ attenuates ethanol-induced Cyp2b10 expression in Pparβ/δ+/+ liver but not in Pparβ/δ-/- liver. Strikingly, Cyp2b10 suppression by ligand activation of PPARβ/δ following ethanol treatment occurred in hepatocytes and was mediated by paracrine signaling from Kupffer cells. Combined, results from the present study demonstrate a novel regulatory role of PPARβ/δ in modulating CYP2B10 that may contribute to the etiology of alcoholic liver disease.
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Affiliation(s)
- Takayuki Koga
- From the Department of Veterinary and Biomedical Sciences and the Center of Molecular Toxicology and Carcinogenesis, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Pei-Li Yao
- From the Department of Veterinary and Biomedical Sciences and the Center of Molecular Toxicology and Carcinogenesis, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Maryam Goudarzi
- the Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, D. C., 20057, and
| | - Iain A Murray
- From the Department of Veterinary and Biomedical Sciences and the Center of Molecular Toxicology and Carcinogenesis, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gayathri Balandaram
- From the Department of Veterinary and Biomedical Sciences and the Center of Molecular Toxicology and Carcinogenesis, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Frank J Gonzalez
- the Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland 20892
| | - Gary H Perdew
- From the Department of Veterinary and Biomedical Sciences and the Center of Molecular Toxicology and Carcinogenesis, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Albert J Fornace
- the Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, D. C., 20057, and
| | - Jeffrey M Peters
- From the Department of Veterinary and Biomedical Sciences and the Center of Molecular Toxicology and Carcinogenesis, Pennsylvania State University, University Park, Pennsylvania 16802,
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Hubbard TD, Murray IA, Bisson WH, Sullivan AP, Sebastian A, Perry GH, Jablonski NG, Perdew GH. Divergent Ah Receptor Ligand Selectivity during Hominin Evolution. Mol Biol Evol 2016; 33:2648-58. [PMID: 27486223 DOI: 10.1093/molbev/msw143] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We have identified a fixed nonsynonymous sequence difference between humans (Val381; derived variant) and Neandertals (Ala381; ancestral variant) in the ligand-binding domain of the aryl hydrocarbon receptor (AHR) gene. In an exome sequence analysis of four Neandertal and Denisovan individuals compared with nine modern humans, there are only 90 total nucleotide sites genome-wide for which archaic hominins are fixed for the ancestral nonsynonymous variant and the modern humans are fixed for the derived variant. Of those sites, only 27, including Val381 in the AHR, also have no reported variability in the human dbSNP database, further suggesting that this highly conserved functional variant is a rare event. Functional analysis of the amino acid variant Ala381 within the AHR carried by Neandertals and nonhuman primates indicate enhanced polycyclic aromatic hydrocarbon (PAH) binding, DNA binding capacity, and AHR mediated transcriptional activity compared with the human AHR. Also relative to human AHR, the Neandertal AHR exhibited 150-1000 times greater sensitivity to induction of Cyp1a1 and Cyp1b1 expression by PAHs (e.g., benzo(a)pyrene). The resulting CYP1A1/CYP1B1 enzymes are responsible for PAH first pass metabolism, which can result in the generation of toxic intermediates and perhaps AHR-associated toxicities. In contrast, the human AHR retains the ancestral sensitivity observed in primates to nontoxic endogenous AHR ligands (e.g., indole, indoxyl sulfate). Our findings reveal that a functionally significant change in the AHR occurred uniquely in humans, relative to other primates, that would attenuate the response to many environmental pollutants, including chemicals present in smoke from fire use during cooking.
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Affiliation(s)
- Troy D Hubbard
- Department of Veterinary and Biomedical Sciences and Center for Molecular Toxicology and Carcinogenesis, Pennsylvania State University
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences and Center for Molecular Toxicology and Carcinogenesis, Pennsylvania State University
| | - William H Bisson
- Department of Environmental and Molecular Toxicology, Oregon State University
| | | | | | - George H Perry
- Department of Biology, Pennsylvania State University Department of Anthropology, Pennsylvania State University
| | | | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences and Center for Molecular Toxicology and Carcinogenesis, Pennsylvania State University
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Balandaram G, Kramer LR, Kang BH, Murray IA, Perdew GH, Gonzalez FJ, Peters JM. Ligand activation of peroxisome proliferator-activated receptor-β/δ suppresses liver tumorigenesis in hepatitis B transgenic mice. Toxicology 2016; 363-364:1-9. [PMID: 27427494 DOI: 10.1016/j.tox.2016.07.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/05/2016] [Accepted: 07/13/2016] [Indexed: 12/13/2022]
Abstract
Peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) inhibits steatosis and inflammation, known risk factors for liver cancer. In this study, the effect of ligand activation of PPARβ/δ in modulating liver tumorigenesis in transgenic hepatitis B virus (HBV) mice was examined. Activation of PPARβ/δ in HBV mice reduced steatosis, the average number of liver foci, and tumor multiplicity. Reduced expression of hepatic CYCLIN D1 and c-MYC, tumor necrosis factor alpha (Tnfa) mRNA, serum levels of alanine aminotransaminase, and an increase in apoptotic signaling was also observed following ligand activation of PPARβ/δ in HBV mice compared to controls. Inhibition of Tnfa mRNA expression was not observed in wild-type hepatocytes. Ligand activation of PPARβ/δ inhibited lipopolysaccharide (LPS)-induced mRNA expression of Tnfa in wild-type, but not in Pparβ/δ-null Kupffer cells. Interestingly, LPS-induced expression of Tnfa mRNA was also inhibited in Kupffer cells from a transgenic mouse line that expressed a DNA binding mutant form of PPARβ/δ compared to controls. Combined, these results suggest that ligand activation of PPARβ/δ attenuates hepatic tumorigenesis in HBV transgenic mice by inhibiting steatosis and cell proliferation, enhancing hepatocyte apoptosis, and modulating anti-inflammatory activity in Kupffer cells.
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Affiliation(s)
- Gayathri Balandaram
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Lance R Kramer
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Boo-Hyon Kang
- Chemon Nonclinical Research Institute, 240 Nampyeong-ro, Yangji-myeon, Cheoin-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, MD, USA
| | - Jeffrey M Peters
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA.
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Gutierrez MA, Davis SS, Rosko A, Nguyen SM, Mitchell KP, Mateen S, Neves J, Garcia TY, Mooney S, Perdew GH, Hubbard TD, Lamba DA, Ramanathan A. A novel AhR ligand, 2AI, protects the retina from environmental stress. Sci Rep 2016; 6:29025. [PMID: 27364765 PMCID: PMC4929558 DOI: 10.1038/srep29025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/14/2016] [Indexed: 12/31/2022] Open
Abstract
Various retinal degenerative diseases including dry and neovascular age-related macular degeneration (AMD), retinitis pigmentosa, and diabetic retinopathy are associated with the degeneration of the retinal pigmented epithelial (RPE) layer of the retina. This consequently results in the death of rod and cone photoreceptors that they support, structurally and functionally leading to legal or complete blindness. Therefore, developing therapeutic strategies to preserve cellular homeostasis in the RPE would be a favorable asset in the clinic. The aryl hydrocarbon receptor (AhR) is a conserved, environmental ligand-dependent, per ARNT-sim (PAS) domain containing bHLH transcription factor that mediates adaptive response to stress via its downstream transcriptional targets. Using in silico, in vitro and in vivo assays, we identified 2,2′-aminophenyl indole (2AI) as a potent synthetic ligand of AhR that protects RPE cells in vitro from lipid peroxidation cytotoxicity mediated by 4-hydroxynonenal (4HNE) as well as the retina in vivo from light-damage. Additionally, metabolic characterization of this molecule by LC-MS suggests that 2AI alters the lipid metabolism of RPE cells, enhancing the intracellular levels of palmitoleic acid. Finally, we show that, as a downstream effector of 2AI-mediated AhR activation, palmitoleic acid protects RPE cells from 4HNE-mediated stress, and light mediated retinal degeneration in mice.
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Affiliation(s)
- Mark A Gutierrez
- University of Denver, Colorado 2199 S University Blvd, Denver, CO 80208, USA
| | - Sonnet S Davis
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Andrew Rosko
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Steven M Nguyen
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Kylie P Mitchell
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Samiha Mateen
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Joana Neves
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Thelma Y Garcia
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Shaun Mooney
- University of Washington Box 358047 Seattle, WA 98195, USA
| | - Gary H Perdew
- The Pennsylvania State University, Center for Molecular Toxicology and Carcinogenesis, 309 Life Sciences Building, University Park, PA 16802, USA
| | - Troy D Hubbard
- The Pennsylvania State University, Center for Molecular Toxicology and Carcinogenesis, 309 Life Sciences Building, University Park, PA 16802, USA
| | - Deepak A Lamba
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
| | - Arvind Ramanathan
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94901, USA
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47
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Girer NG, Murray IA, Omiecinski CJ, Perdew GH. Hepatic Aryl Hydrocarbon Receptor Attenuates Fibroblast Growth Factor 21 Expression. J Biol Chem 2016; 291:15378-87. [PMID: 27226639 DOI: 10.1074/jbc.m116.715151] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Indexed: 12/13/2022] Open
Abstract
The Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor involved in many physiological processes. Several studies indicate that AHR is also involved in energy homeostasis. Fibroblast growth factor 21 (FGF21) is an important regulator of the fasting and feeding responses. When administered to various genetic and diet-induced mouse models of obesity, FGF21 can attenuate obesity-associated morbidities. Here, we explore the role of AHR in hepatic Fgf21 expression through the use of a conditional, hepatocyte-targeted AHR knock-out mouse model (Cre(Alb)Ahr(Fx/Fx)). Compared with the congenic parental strain (Ahr(Fx/Fx)), non-fasted Cre(Alb)Ahr(Fx/Fx) mice exhibit a 4-fold increase in hepatic Fgf21 expression, as well as elevated expression of the FGF21-target gene Igfbp1 Furthermore, in vivo agonist activation of AHR reduces hepatic Fgf21 expression during a fast. The Fgf21 promoter contains several putative dioxin response elements (DREs). Using EMSA, we demonstrate that the AHR-ARNT heterodimer binds to a specific DRE that overlaps binding sequences for peroxisome proliferator-activated receptor α (PPARα), carbohydrate response element-binding protein (ChREBP), and cAMP response element-binding protein, hepatocyte specific (CREBH). In addition, we reveal that agonist-activated AHR impairs PPARα-, ChREBP-, and CREBH-mediated promoter activity in Hepa-1 cells. Accordingly, agonist treatment in Hepa-1 cells ablates potent ER stress-driven Fgf21 expression, and pre-treatment with AHR antagonist blocks this effect. Finally, we show that pre-treatment of primary human hepatocytes with AHR agonist diminishes PPARα-, glucose-, and ER stress-driven induction of FGF21 expression, indicating the effect is not mouse-specific. Together, our data show that AHR contributes to hepatic energy homeostasis, partly through the regulation of FGF21 expression and signaling.
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Affiliation(s)
| | - Iain A Murray
- the Department of Veterinary and Biomedical Sciences, and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Curtis J Omiecinski
- the Department of Veterinary and Biomedical Sciences, and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gary H Perdew
- the Department of Veterinary and Biomedical Sciences, and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
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48
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Yang J, Hu S, Zhao L, Kaplan DH, Perdew GH, Xiong N. Selective programming of CCR10(+) innate lymphoid cells in skin-draining lymph nodes for cutaneous homeostatic regulation. Nat Immunol 2015; 17:48-56. [PMID: 26523865 PMCID: PMC4838393 DOI: 10.1038/ni.3312] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/29/2015] [Indexed: 12/15/2022]
Abstract
Innate lymphoid cells (ILCs) 'preferentially' localize into barrier tissues, where they function in tissue protection but can also contribute to inflammatory diseases. The mechanisms that regulate the establishment of ILCs in barrier tissues are poorly understood. Here we found that under steady-state conditions, ILCs in skin-draining lymph nodes (sLNs) were continuously activated to acquire regulatory properties and high expression of the chemokine receptor CCR10 for localization into the skin. CCR10(+) ILCs promoted the homeostasis of skin-resident T cells and, reciprocally, their establishment in the skin required T cell-regulated homeostatic environments. CD207(+) dendritic cells expressing the transcription factor Foxn1 were required for the proper generation of CCR10(+) ILCs. These observations reveal mechanisms that underlie the specific programming and priming of skin-homing CCR10(+) ILCs in the sLNs.
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Affiliation(s)
- Jie Yang
- Center for Molecular Immunology and Infectious Disease, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Shaomin Hu
- Center for Molecular Immunology and Infectious Disease, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Luming Zhao
- Center for Molecular Immunology and Infectious Disease, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Daniel H Kaplan
- Department of Dermatology, Center for Immunology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Gary H Perdew
- Center for Molecular Toxicology &Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Na Xiong
- Center for Molecular Immunology and Infectious Disease, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
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49
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Hubbard TD, Murray IA, Perdew GH. Indole and Tryptophan Metabolism: Endogenous and Dietary Routes to Ah Receptor Activation. Drug Metab Dispos 2015; 43:1522-35. [PMID: 26041783 PMCID: PMC4576673 DOI: 10.1124/dmd.115.064246] [Citation(s) in RCA: 399] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/02/2015] [Indexed: 12/31/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor recognized for its role in xenobiotic metabolism. The physiologic function of AHR has expanded to include roles in immune regulation, organogenesis, mucosal barrier function, and the cell cycle. These functions are likely dependent upon ligand-mediated activation of the receptor. High-affinity ligands of AHR have been classically defined as xenobiotics, such as polychlorinated biphenyls and dioxins. Identification of endogenous AHR ligands is key to understanding the physiologic functions of this enigmatic receptor. Metabolic pathways targeting the amino acid tryptophan and indole can lead to a myriad of metabolites, some of which are AHR ligands. Many of these ligands exhibit species selective preferential binding to AHR. The discovery of specific tryptophan metabolites as AHR ligands may provide insight concerning where AHR is activated in an organism, such as at the site of inflammation and within the intestinal tract.
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Affiliation(s)
- Troy D Hubbard
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology (T.D.H.), and Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences (T.D.H., I.A.M., G.H.P)., Pennsylvania State University, University Park, Pennsylvania
| | - Iain A Murray
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology (T.D.H.), and Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences (T.D.H., I.A.M., G.H.P)., Pennsylvania State University, University Park, Pennsylvania
| | - Gary H Perdew
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology (T.D.H.), and Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences (T.D.H., I.A.M., G.H.P)., Pennsylvania State University, University Park, Pennsylvania
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Lahoti TS, Boyer JA, Kusnadi A, Muku GE, Murray IA, Perdew GH. Aryl Hydrocarbon Receptor Activation Synergistically Induces Lipopolysaccharide-Mediated Expression of Proinflammatory Chemokine (c-c motif) Ligand 20. Toxicol Sci 2015; 148:229-40. [PMID: 26259605 DOI: 10.1093/toxsci/kfv178] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The Ah receptor (AHR) is directly involved in the regulation of both innate and adaptive immunity. However, these activities are poorly understood at the level of gene regulation. The chemokine (c-c motif) ligand 20 (CCL20) plays a nonredundant role in the chemoattraction of C-C motif receptor 6 expressing cells (eg, T cells and others). A survey of promoter regions of chemokine genes revealed that there are several putative dioxin responsive elements in the mouse Ccl20 promoter. The addition of an AHR agonist along with lipopolysaccharide (LPS) to cultured primary peritoneal macrophages results in synergistic induction of both Ccl20 mRNA and protein, compared with each compound alone. Through the use of macrophage cultures derived from Ahr(-) (/) (-) and Ahr(nls/nls) mice, it was established that expression of the AHR and its ability to translocate into the nucleus are necessary for AHR ligand-mediated synergistic induction of Ccl20. Gel shift analysis determined that a potent tandem AHR binding site ~3.1 kb upstream from the transcriptional start site can efficiently bind the AHR/ARNT (aryl hydrocarbon receptor/AHR nuclear translocator) heterodimer upon activation with a number of AHR agonists. Furthermore, studies reveal that LPS increases AHR levels on the Ccl20 promoter while decreasing HDAC1 occupancy. The level of Ccl20 constitutive expression in the colon is greatly attenuated in Ahr(-) (/) (-) mice. These studies suggest that the presence of AHR ligands during localized inflammation may augment chemokine expression, thus participating in the overall response to pathogens.
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Affiliation(s)
- Tejas S Lahoti
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, Pennsylvania 16802
| | - Jacob A Boyer
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, Pennsylvania 16802
| | - Ann Kusnadi
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, Pennsylvania 16802
| | - Gulsum E Muku
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, Pennsylvania 16802
| | - Iain A Murray
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, Pennsylvania 16802
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, Penn State University, University Park, Pennsylvania 16802
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