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Cholico GN, Fling RR, Sink WJ, Nault R, Zacharewski T. Inhibition of the urea cycle by the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin increases serum ammonia levels in mice. J Biol Chem 2024; 300:105500. [PMID: 38013089 PMCID: PMC10731612 DOI: 10.1016/j.jbc.2023.105500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/26/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023] Open
Abstract
The aryl hydrocarbon receptor is a ligand-activated transcription factor known for mediating the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. TCDD induces nonalcoholic fatty liver disease (NAFLD)-like pathologies including simple steatosis that can progress to steatohepatitis with fibrosis and bile duct proliferation in male mice. Dose-dependent progression of steatosis to steatohepatitis with fibrosis by TCDD has been associated with metabolic reprogramming, including the disruption of amino acid metabolism. Here, we used targeted metabolomic analysis to reveal dose-dependent changes in the level of ten serum and eleven hepatic amino acids in mice upon treatment with TCDD. Bulk RNA-seq and protein analysis showed TCDD repressed CPS1, OTS, ASS1, ASL, and GLUL, all of which are associated with the urea cycle and glutamine biosynthesis. Urea and glutamine are end products of the detoxification and excretion of ammonia, a toxic byproduct of amino acid catabolism. Furthermore, we found that the catalytic activity of OTC, a rate-limiting step in the urea cycle was also dose dependently repressed. These results are consistent with an increase in circulating ammonia. Collectively, the repression of the urea and glutamate-glutamine cycles increased circulating ammonia levels and the toxicity of TCDD.
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Affiliation(s)
- Giovan N Cholico
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Russell R Fling
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA; Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Warren J Sink
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Rance Nault
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Tim Zacharewski
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA.
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2
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Opitz CA, Holfelder P, Prentzell MT, Trump S. The complex biology of aryl hydrocarbon receptor activation in cancer and beyond. Biochem Pharmacol 2023; 216:115798. [PMID: 37696456 PMCID: PMC10570930 DOI: 10.1016/j.bcp.2023.115798] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
The aryl hydrocarbon receptor (AHR) signaling pathway is a complex regulatory network that plays a critical role in various biological processes, including cellular metabolism, development, and immune responses. The complexity of AHR signaling arises from multiple factors, including the diverse ligands that activate the receptor, the expression level of AHR itself, and its interaction with the AHR nuclear translocator (ARNT). Additionally, the AHR crosstalks with the AHR repressor (AHRR) or other transcription factors and signaling pathways and it can also mediate non-genomic effects. Finally, posttranslational modifications of the AHR and its interaction partners, epigenetic regulation of AHR and its target genes, as well as AHR-mediated induction of enzymes that degrade AHR-activating ligands may contribute to the context-specificity of AHR activation. Understanding the complexity of AHR signaling is crucial for deciphering its physiological and pathological roles and developing therapeutic strategies targeting this pathway. Ongoing research continues to unravel the intricacies of AHR signaling, shedding light on the regulatory mechanisms controlling its diverse functions.
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Affiliation(s)
- Christiane A Opitz
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Neurology Clinic and National Center for Tumor Diseases, 69120 Heidelberg, Germany.
| | - Pauline Holfelder
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Faculty of Bioscience, Heidelberg University, 69120 Heidelberg, Germany
| | - Mirja Tamara Prentzell
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Faculty of Bioscience, Heidelberg University, 69120 Heidelberg, Germany
| | - Saskia Trump
- Molecular Epidemiology Unit, Berlin Institute of Health at Charité and the German Cancer Consortium (DKTK), Partner Site Berlin, a partnership between DKFZ and Charité -Universitätsmedizin Berlin, 10117 Berlin, Germany
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3
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Patil NY, Rus I, Joshi AD. Role of ERK1/2 Signaling in Cinnabarinic Acid-Driven Stanniocalcin 2-Mediated Protection against Alcohol-Induced Apoptosis. J Pharmacol Exp Ther 2023; 387:111-120. [PMID: 37562971 PMCID: PMC10519581 DOI: 10.1124/jpet.123.001670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 08/12/2023] Open
Abstract
We have previously shown that a bona fide aryl hydrocarbon receptor (AhR) agonist, cinnabarinic acid (CA), protects against alcohol-induced hepatocyte apoptosis via activation of a novel AhR target gene, stanniocalcin 2 (Stc2). Stc2 translates to a secreted disulfide-linked hormone, STC2, known to function in cell development, calcium and phosphate regulation, angiogenesis, and antiapoptosis-albeit the comprehensive mechanism by which the CA-AhR-STC2 axis confers antiapoptosis is yet to be characterized. In this study, using RNA interference library screening, downstream antiapoptotic molecular signaling components involved in CA-induced STC2-mediated protection against ethanol-induced apoptosis were investigated. RNA interference library screening of kinases and phosphatases in Hepa1 cells and subsequent pathway analysis identified mitogen-activated protein kinase (MAPK) signaling as a critical molecular pathway involved in CA-mediated protection. Specifically, phosphorylation of ERK1/2 was induced in response to CA treatment without alterations in p38 and JNK signaling pathways. Silencing Stc2 in Hepa1 cells and in vivo experiments performed in Stc2-/- (Stc2 knockout) mice, which failed to confer CA-mediated protection against ethanol-induced apoptosis, showed abrogation of ERK1/2 activation, underlining the significance of ERK1/2 signaling in CA-STC2-mediated protection. In conclusion, activation of ERK1/2 signaling in CA-driven AhR-dependent Stc2-mediated protection represents a novel mechanism of protection against acute alcohol-induced apoptosis. SIGNIFICANCE STATEMENT: Previous studies have shown the role of stanniocalcin 2 (Stc2) in cinnabarinic acid (CA)-mediated protection against alcohol-induced apoptosis. Here, using RNA interference library screening and subsequent in vivo studies, the functional significance of ERK1/2 activation in CA-induced Stc2-mediated protection against acute ethanol-induced apoptosis was identified. This study is thus significant as it illustrates a comprehensive downstream mechanism by which CA-induced Stc2 protects against alcoholic liver disease.
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Affiliation(s)
- Nikhil Y Patil
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Iulia Rus
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Aditya D Joshi
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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4
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Zuberi A, Huang Y, Dotts AJ, Wei H, Coon JS, Liu S, Iizuka T, Wu O, Sotos O, Saini P, Chakravarti D, Boyer TG, Dai Y, Bulun SE, Yin P. MED12 mutation activates the tryptophan/kynurenine/AHR pathway to promote growth of uterine leiomyomas. JCI Insight 2023; 8:e171305. [PMID: 37607000 PMCID: PMC10561729 DOI: 10.1172/jci.insight.171305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/15/2023] [Indexed: 08/23/2023] Open
Abstract
Uterine leiomyomas cause heavy menstrual bleeding, anemia, and pregnancy loss in millions of women worldwide. Driver mutations in the transcriptional mediator complex subunit 12 (MED12) gene in uterine myometrial cells initiate 70% of leiomyomas that grow in a progesterone-dependent manner. We showed a distinct chromatin occupancy landscape of MED12 in mutant MED12 (mut-MED12) versus WT-MED12 leiomyomas. Integration of cistromic and transcriptomics data identified tryptophan 2,3-dioxygenase (TDO2) as the top mut-MED12 target gene that was significantly upregulated in mut-MED12 leiomyomas when compared with adjacent myometrium and WT-MED12 leiomyomas. TDO2 catalyzes the conversion of tryptophan to kynurenine, an aryl hydrocarbon receptor (AHR) ligand that we confirmed to be significantly elevated in mut-MED12 leiomyomas. Treatment of primary mut-MED12 leiomyoma cells with tryptophan or kynurenine stimulated AHR nuclear translocation, increased proliferation, inhibited apoptosis, and induced AHR-target gene expression, whereas blocking the TDO2/kynurenine/AHR pathway by siRNA or pharmacological treatment abolished these effects. Progesterone receptors regulated the expression of AHR and its target genes. In vivo, TDO2 expression positively correlated with the expression of genes crucial for leiomyoma growth. In summary, activation of the TDO2/kynurenine/AHR pathway selectively in mut-MED12 leiomyomas promoted tumor growth and may inform the future development of targeted treatments and precision medicine.
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Affiliation(s)
- Azna Zuberi
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Yongchao Huang
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Ariel J. Dotts
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Helen Wei
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - John S. Coon
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Shimeng Liu
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Takashi Iizuka
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Olivia Wu
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Olivia Sotos
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Priyanka Saini
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Debabrata Chakravarti
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Thomas G. Boyer
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Yang Dai
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Serdar E. Bulun
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Ping Yin
- Division of Reproductive Science in Medicine, Department of Obstetrics & Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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5
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You Y, Tsai CF, Patel R, Sarkar S, Clair G, Zhou M, Liu T, Metz TO, Das C, Nakayasu ES. Analysis of a macrophage carbamylated proteome reveals a function in post-translational modification crosstalk. Cell Commun Signal 2023; 21:241. [PMID: 37723562 PMCID: PMC10506243 DOI: 10.1186/s12964-023-01257-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 08/05/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Lysine carbamylation is a biomarker of rheumatoid arthritis and kidney diseases. However, its cellular function is understudied due to the lack of tools for systematic analysis of this post-translational modification (PTM). METHODS We adapted a method to analyze carbamylated peptides by co-affinity purification with acetylated peptides based on the cross-reactivity of anti-acetyllysine antibodies. We also performed immobilized-metal affinity chromatography to enrich for phosphopeptides, which allowed us to obtain multi-PTM information from the same samples. RESULTS By testing the pipeline with RAW 264.7 macrophages treated with bacterial lipopolysaccharide, 7,299, 8,923 and 47,637 acetylated, carbamylated, and phosphorylated peptides were identified, respectively. Our analysis showed that carbamylation occurs on proteins from a variety of functions on sites with similar as well as distinct motifs compared to acetylation. To investigate possible PTM crosstalk, we integrated the carbamylation data with acetylation and phosphorylation data, leading to the identification 1,183 proteins that were modified by all 3 PTMs. Among these proteins, 54 had all 3 PTMs regulated by lipopolysaccharide and were enriched in immune signaling pathways, and in particular, the ubiquitin-proteasome pathway. We found that carbamylation of linear diubiquitin blocks the activity of the anti-inflammatory deubiquitinase OTULIN. CONCLUSIONS Overall, our data show that anti-acetyllysine antibodies can be used for effective enrichment of carbamylated peptides. Moreover, carbamylation may play a role in PTM crosstalk with acetylation and phosphorylation, and that it is involved in regulating ubiquitination in vitro. Video Abstract.
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Affiliation(s)
- Youngki You
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Chia-Feng Tsai
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Rishi Patel
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Soumyadeep Sarkar
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Geremy Clair
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Mowei Zhou
- Environmental and Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Tao Liu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Thomas O Metz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Chittaranjan Das
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Ernesto S Nakayasu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
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6
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You Y, Tsai CF, Patel R, Sarkar S, Clair G, Zhou M, Liu T, Metz TO, Das C, Nakayasu ES. Analysis of a macrophage carbamylated proteome reveals a function in post-translational modification crosstalk. RESEARCH SQUARE 2023:rs.3.rs-3044777. [PMID: 37398265 PMCID: PMC10312928 DOI: 10.21203/rs.3.rs-3044777/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Background. Lysine carbamylation is a biomarker of rheumatoid arthritis and kidney diseases. However, its cellular function is understudied due to the lack of tools for systematic analysis of this post-translational modification (PTM). Methods. We adapted a method to analyze carbamylated peptides by co-affinity purification with acetylated peptides based on the cross-reactivity of anti-acetyllysine antibodies. We integrated this method into a mass spectrometry-based multi-PTM pipeline to simultaneously analyze carbamylated and acetylated peptides in addition to phosphopeptides were enriched by sequential immobilized-metal affinity chromatography. Results. By testing the pipeline with RAW 264.7 macrophages treated with bacterial lipopolysaccharide, 7,299, 8,923 and 47,637 acetylated, carbamylated, and phosphorylated peptides were identified, respectively. Our analysis showed that carbamylation occurs on proteins from a variety of functions on sites with similar as well as distinct motifs compared to acetylation. To investigate possible PTM crosstalk, we integrated the carbamylation data with acetylation and phosphorylation data, leading to the identification 1,183 proteins that were modified by all 3 PTMs. Among these proteins, 54 had all 3 PTMs regulated by lipopolysaccharide and were enriched in immune signaling pathways, and in particular, the ubiquitin-proteasome pathway. We found that carbamylation of linear diubiquitin blocks the activity of the anti-inflammatory deubiquitinase OTULIN. Conclusions Overall, our data show that anti-acetyllysine antibodies can be used for effective enrichment of carbamylated peptides. Moreover, carbamylation may play a role in PTM crosstalk with acetylation and phosphorylation, and that it is involved in regulating ubiquitination in vitro .
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Affiliation(s)
| | | | | | | | | | | | - Tao Liu
- Pacific Northwest National Laboratory
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7
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Patel TD, Nakka M, Grimm SL, Coarfa C, Gorelick DA. Functional genomic analysis of non-canonical DNA regulatory elements of the aryl hydrocarbon receptor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.538985. [PMID: 37205451 PMCID: PMC10187216 DOI: 10.1101/2023.05.01.538985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that binds DNA and regulates genes in response to halogenated and polycyclic aromatic hydrocarbons. AHR also regulates the development and function of the liver and the immune system. In the canonical pathway, AHR binds a consensus DNA sequence, termed the xenobiotic response element (XRE), recruits protein coregulators, and regulates target gene expression. Emerging evidence suggests that AHR may regulate gene expression via an additional pathway, by binding to a non-consensus DNA sequence termed the non-consensus XRE (NC-XRE). The prevalence of NC-XRE motifs in the genome is not known. Studies using chromatin immunoprecipitation and reporter genes provide indirect evidence of AHR-NC-XRE interactions, but direct evidence for an AHR-NCXRE interaction that regulates transcription in a natural genomic context is lacking. Here, we analyzed AHR binding to NC-XRE DNA on a genome-wide scale in mouse liver. We integrated ChIP-seq and RNA-seq data and identified putative AHR target genes with NC-XRE motifs in regulatory regions. We also performed functional genomics at a single locus, the mouse Serpine1 gene. Deleting NC-XRE motifs from the Serpine1 promoter reduced the upregulation of Serpine1 by TCDD, an AHR ligand. We conclude that AHR upregulates Serpine1 via NC-XRE DNA. NC-XRE motifs are prevalent throughout regions of the genome where AHR binds. Taken together, our results suggest that AHR regulates genes via NC-XRE motifs. Our results will also improve our ability to identify AHR target genes and their physiologic relevance.
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Affiliation(s)
- Tajhal D Patel
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - Manjula Nakka
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
| | - Sandra L Grimm
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - Cristian Coarfa
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - Daniel A Gorelick
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
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8
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Patil NY, Friedman JE, Joshi AD. Role of Hepatic Aryl Hydrocarbon Receptor in Non-Alcoholic Fatty Liver Disease. RECEPTORS (BASEL, SWITZERLAND) 2023; 2:1-15. [PMID: 37284280 PMCID: PMC10240927 DOI: 10.3390/receptors2010001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Numerous nuclear receptors including farnesoid X receptor, liver X receptor, peroxisome proliferator-activated receptors, pregnane X receptor, hepatic nuclear factors have been extensively studied within the context of non-alcoholic fatty liver disease (NAFLD). Following the first description of the Aryl hydrocarbon Receptor (AhR) in the 1970s and decades of research which unveiled its role in toxicity and pathophysiological processes, the functional significance of AhR in NAFLD has not been completely decoded. Recently, multiple research groups have utilized a plethora of in vitro and in vivo models that mimic NAFLD pathology to investigate the functional significance of AhR in fatty liver disease. This review provides a comprehensive account of studies describing both the beneficial and possible detrimental role of AhR in NAFLD. A plausible reconciliation for the paradox indicating AhR as a 'double-edged sword' in NAFLD is discussed. Finally, understanding AhR ligands and their signaling in NAFLD will facilitate us to probe AhR as a potential drug target to design innovative therapeutics against NAFLD in the near future.
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Affiliation(s)
- Nikhil Y. Patil
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Jacob E. Friedman
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Aditya D. Joshi
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
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9
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Trejo-Zambrano MI, Gómez-Bañuelos E, Andrade F. Redox-Mediated Carbamylation As a Hapten Model Applied to the Origin of Antibodies to Modified Proteins in Rheumatoid Arthritis. Antioxid Redox Signal 2022; 36:389-409. [PMID: 33906423 PMCID: PMC8982126 DOI: 10.1089/ars.2021.0064] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 12/23/2022]
Abstract
Significance: The production of antibodies to posttranslationally modified antigens is a hallmark in rheumatoid arthritis (RA). In particular, the presence of citrullination-associated antibodies, targeting both citrullinating enzymes (the peptidylarginine deiminases [PADs]) and citrullinated antigens (anticitrullinated protein antibodies [ACPAs]), has suggested that dysregulated citrullination is relevant for disease pathogenesis. Antibodies to other protein modifications with physicochemical similarities to citrulline, such as carbamylated-lysine and acetylated-lysine, have also gained interest in RA, but their mechanistic relation to ACPAs remains unclear. Recent Advances: Recent studies using RA-derived monoclonal antibodies have found that ACPAs are cross-reactive to carbamylated and acetylated peptides, challenging our understanding of the implications of such cross-reactivity. Critical Issues: Analogous to the classic antibody response to chemically modified proteins, we examine the possibility that antibodies to modified proteins in RA are more likely to resemble antihapten antibodies rather than autoantibodies. This potential shift in the autoantibody paradigm in RA offers the opportunity to explore new mechanisms involved in the origin and cross-reactivity of pathogenic antibodies in RA. In contrast to citrullination, carbamylation is a chemical modification associated with oxidative stress, it is highly immunogenic, and is considered in the group of posttranslational modification-derived products. We discuss the possibility that carbamylated proteins are antigenic drivers of cross-reacting antihapten antibodies that further create the ACPA response, and that ACPAs may direct the production of antibodies to PAD enzymes. Future Directions: Understanding the complexity of autoantibodies in RA is critical to develop tools to clearly define their origin, identify drivers of disease propagation, and develop novel therapeutics. Antioxid. Redox Signal. 36, 389-409.
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Affiliation(s)
| | - Eduardo Gómez-Bañuelos
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Felipe Andrade
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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10
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Lassak J, Sieber A, Hellwig M. Exceptionally versatile take II: post-translational modifications of lysine and their impact on bacterial physiology. Biol Chem 2022; 403:819-858. [PMID: 35172419 DOI: 10.1515/hsz-2021-0382] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/05/2022] [Indexed: 01/16/2023]
Abstract
Among the 22 proteinogenic amino acids, lysine sticks out due to its unparalleled chemical diversity of post-translational modifications. This results in a wide range of possibilities to influence protein function and hence modulate cellular physiology. Concomitantly, lysine derivatives form a metabolic reservoir that can confer selective advantages to those organisms that can utilize it. In this review, we provide examples of selected lysine modifications and describe their role in bacterial physiology.
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Affiliation(s)
- Jürgen Lassak
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, D-82152 Planegg, Germany
| | - Alina Sieber
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, D-82152 Planegg, Germany
| | - Michael Hellwig
- Technische Universität Braunschweig - Institute of Food Chemistry, Schleinitzstraße 20, D-38106 Braunschweig, Germany
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11
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Girer NG, Tomlinson CR, Elferink CJ. The Aryl Hydrocarbon Receptor in Energy Balance: The Road from Dioxin-Induced Wasting Syndrome to Combating Obesity with Ahr Ligands. Int J Mol Sci 2020; 22:E49. [PMID: 33374508 PMCID: PMC7793057 DOI: 10.3390/ijms22010049] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 02/07/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) has been studied for over 40 years, yet our understanding of this ligand-activated transcription factor remains incomplete. Each year, novel findings continually force us to rethink the role of the AHR in mammalian biology. The AHR has historically been studied within the context of potent activation via AHR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with a focus on how the AHR mediates TCDD toxicity. Research has subsequently revealed that the AHR is actively involved in distinct physiological processes ranging from the development of the liver and reproductive organs, to immune system function and wound healing. More recently, the AHR was implicated in the regulation of energy metabolism and is currently being investigated as a potential therapeutic target for obesity. In this review, we re-trace the steps through which the early toxicological studies of TCDD led to the conceptual framework for the AHR as a potential therapeutic target in metabolic disease. We additionally discuss the key discoveries that have been made concerning the role of the AHR in energy metabolism, as well as the current and future directions of the field.
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Affiliation(s)
- Nathaniel G. Girer
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX 77550, USA;
| | - Craig R. Tomlinson
- Department of Molecular and Systems Biology, Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Dartmouth College, Lebanon, NH 03756, USA;
| | - Cornelis J. Elferink
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX 77550, USA;
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O'Neil LJ, Barrera-Vargas A, Sandoval-Heglund D, Merayo-Chalico J, Aguirre-Aguilar E, Aponte AM, Ruiz-Perdomo Y, Gucek M, El-Gabalawy H, Fox DA, Katz JD, Kaplan MJ, Carmona-Rivera C. Neutrophil-mediated carbamylation promotes articular damage in rheumatoid arthritis. SCIENCE ADVANCES 2020; 6:6/44/eabd2688. [PMID: 33115748 PMCID: PMC7608797 DOI: 10.1126/sciadv.abd2688] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/11/2020] [Indexed: 05/22/2023]
Abstract
Formation of autoantibodies to carbamylated proteins (anti-CarP) is considered detrimental in the prognosis of erosive rheumatoid arthritis (RA). The source of carbamylated antigens and the mechanisms by which anti-CarP antibodies promote bone erosion in RA remain unknown. Here, we find that neutrophil extracellular traps (NETs) externalize carbamylated proteins and that RA subjects develop autoantibodies against carbamylated NET (cNET) antigens that, in turn, correlate with levels of anti-CarP. Transgenic mice expressing the human RA shared epitope (HLADRB1* 04:01) immunized with cNETs develop antibodies to citrullinated and carbamylated proteins. Furthermore, anti-carbamylated histone antibodies correlate with radiographic bone erosion in RA subjects. Moreover, anti-carbamylated histone-immunoglobulin G immune complexes promote osteoclast differentiation and potentiate osteoclast-mediated matrix resorption. These results demonstrate that carbamylated proteins present in NETs enhance pathogenic immune responses and bone destruction, which may explain the association between anti-CarP and erosive arthritis in RA.
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Affiliation(s)
- Liam J O'Neil
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Manitoba Centre for Proteomics and Systems Biology, Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Ana Barrera-Vargas
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Medicas y de la Nutricion, Salvador Zubiran, Mexico City, Mexico
| | - Donavon Sandoval-Heglund
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Javier Merayo-Chalico
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Medicas y de la Nutricion, Salvador Zubiran, Mexico City, Mexico
| | - Eduardo Aguirre-Aguilar
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Medicas y de la Nutricion, Salvador Zubiran, Mexico City, Mexico
| | - Angel M Aponte
- Proteomic Core, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yanira Ruiz-Perdomo
- Office of the Clinical Director, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marjan Gucek
- Proteomic Core, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hani El-Gabalawy
- Manitoba Centre for Proteomics and Systems Biology, Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - David A Fox
- Division of Rheumatology and Clinical Autoimmunity Center of Excellence, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - James D Katz
- Office of the Clinical Director, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mariana J Kaplan
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Carmelo Carmona-Rivera
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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13
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Wajda A, Łapczuk-Romańska J, Paradowska-Gorycka A. Epigenetic Regulations of AhR in the Aspect of Immunomodulation. Int J Mol Sci 2020; 21:E6404. [PMID: 32899152 PMCID: PMC7504141 DOI: 10.3390/ijms21176404] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023] Open
Abstract
Environmental factors contribute to autoimmune disease manifestation, and as regarded today, AhR has become an important factor in studies of immunomodulation. Besides immunological aspects, AhR also plays a role in pharmacological, toxicological and many other physiological processes such as adaptive metabolism. In recent years, epigenetic mechanisms have provided new insight into gene regulation and reveal a new contribution to autoimmune disease pathogenesis. DNA methylation, histone modifications, chromatin alterations, microRNA and consequently non-genetic changes in phenotypes connect with environmental factors. Increasing data reveals AhR cross-roads with the most significant in immunology pathways. Although study on epigenetic modulations in autoimmune diseases is still not well understood, therefore future research will help us understand their pathophysiology and help to find new therapeutic strategies. Present literature review sheds the light on the common ground between remodeling chromatin compounds and autoimmune antibodies used in diagnostics. In the proposed review we summarize recent findings that describe epigenetic factors which regulate AhR activity and impact diverse immunological responses and pathological changes.
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Affiliation(s)
- Anna Wajda
- Department of Molecular Biology, National Institute of Geriatrics, Rheumatology and Rehabilitation, 02-637 Warsaw, Poland;
| | - Joanna Łapczuk-Romańska
- Department of Experimental and Clinical Pharmacology, Pomeranian Medical University, 70-111 Szczecin, Poland;
| | - Agnieszka Paradowska-Gorycka
- Department of Molecular Biology, National Institute of Geriatrics, Rheumatology and Rehabilitation, 02-637 Warsaw, Poland;
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Giotopoulou GA, Stathopoulos GT. Effects of Inhaled Tobacco Smoke on the Pulmonary Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1225:53-69. [PMID: 32030647 DOI: 10.1007/978-3-030-35727-6_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tobacco smoke is a multicomponent mixture of chemical, organic, and inorganic compounds, as well as additive substances and radioactive materials. Many studies have proved the carcinogenicity of various of these compounds through the induction of DNA adducts, mutational potential, epigenetic changes, gene fusions, and chromosomal events. The tumor microenvironment plays an important role in malignant tumor formation and progression through the regulation of expression of key molecules which mediate the recruitment of immune cells to the tumor site and subsequently regulate tumor growth and metastasis. In this chapter, we discuss the effects of inhaled tobacco smoke in the tumor microenvironment of the respiratory tract. The mechanisms underlying these effects as well as their link with tumor progression are analyzed.
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Affiliation(s)
- Georgia A Giotopoulou
- Comprehensive Pneumology Center (CPC) and Institute for Lung Biology and Disease (iLBD), University Hospital, Ludwig-Maximilians University and Helmholtz Center Munich, Member of the German Center for Lung Research (DZL), Munich, Bavaria, Germany.
- Laboratory for Molecular Respiratory Carcinogenesis, Faculty of Medicine, University of Patras, Rio, Greece.
| | - Georgios T Stathopoulos
- Comprehensive Pneumology Center (CPC) and Institute for Lung Biology and Disease (iLBD), University Hospital, Ludwig-Maximilians University and Helmholtz Center Munich, Member of the German Center for Lung Research (DZL), Munich, Bavaria, Germany
- Laboratory for Molecular Respiratory Carcinogenesis, Faculty of Medicine, University of Patras, Rio, Greece
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15
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Differentially Expressed Mitochondrial Proteins in Human MCF7 Breast Cancer Cells Resistant to Paclitaxel. Int J Mol Sci 2019; 20:ijms20122986. [PMID: 31248089 PMCID: PMC6628585 DOI: 10.3390/ijms20122986] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/08/2019] [Accepted: 06/17/2019] [Indexed: 12/12/2022] Open
Abstract
Identification of novel proteins with changed expression in resistant cancer cells could be helpful in elucidation mechanisms involved in the development of acquired resistance to paclitaxel. In this study, we carried out a 2D-PAGE using the mitochondrial-enriched fraction from paclitaxel-resistant MCF7/PacR cells compared to original paclitaxel-sensitive MCF7 breast cancer cells. Differentially expressed proteins were identified employing mass spectrometry. We found that lysosomal cathepsin D and mitochondrial abhydrolase-domain containing protein 11 (ABHD11) had decreased expression in MCF7/PacR cells. On the other hand, mitochondrial carbamoyl-phosphate synthetase 1 (CPS1) and ATPase family AAA-domain containing protein 3A and 3B (ATAD3A, ATAD3B) were overexpressed in MCF7/PacR cells. Further, we showed that there was no difference in localization of CPS1 in MCF7 and MCF7/PacR cells. We demonstrated a significant increase in the number of CPS1 positive MCF7/PacR cells, using FACS analysis, compared to the number of CPS1 positive MCF7 cells. Silencing of CPS1 expression by specific siRNA had no significant effect on the resistance of MCF7/PacR cells to paclitaxel. To summarize, we identified several novel proteins of a mitochondrial fraction whose role in acquired resistance to paclitaxel in breast cancer cells should be further assessed.
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Patrizi B, Siciliani de Cumis M. TCDD Toxicity Mediated by Epigenetic Mechanisms. Int J Mol Sci 2018; 19:ijms19124101. [PMID: 30567322 PMCID: PMC6320947 DOI: 10.3390/ijms19124101] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/11/2018] [Accepted: 12/14/2018] [Indexed: 12/27/2022] Open
Abstract
Dioxins are highly toxic and persistent halogenated organic pollutants belonging to two families i.e., Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Polychlorinated Dibenzo Furans (PCDFs). They can cause cancer, reproductive and developmental issues, damage to the immune system, and can deeply interfere with the endocrine system. Dioxins toxicity is mediated by the Aryl-hydrocarbon Receptor (AhR) which mediates the cellular metabolic adaptation to these planar aromatic xenobiotics through the classical transcriptional regulation pathway, including AhR binding of ligand in the cytosol, translocation of the receptor to the nucleus, dimerization with the AhR nuclear translocator, and the binding of this heterodimeric transcription factor to dioxin-responsive elements which regulate the expression of genes involved in xenobiotic metabolism. 2,3,7,8-TCDD is the most toxic among dioxins showing the highest affinity toward the AhR receptor. Beside this classical and well-studied pathway, a number of papers are dealing with the role of epigenetic mechanisms in the response to environmental xenobiotics. In this review, we report on the potential role of epigenetic mechanisms in dioxins-induced cellular response by inspecting recent literature and focusing our attention on epigenetic mechanisms induced by the most toxic 2,3,7,8-TCDD.
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Affiliation(s)
- Barbara Patrizi
- National Institute of Optics-National Research Council (INO-CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy.
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17
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Brown MR, Garside H, Thompson E, Atwal S, Bean C, Goodall T, Sullivan M, Graham MJ. From the Cover: Development and Application of a Dual Rat and Human AHR Activation Assay. Toxicol Sci 2018; 160:408-419. [PMID: 29029351 DOI: 10.1093/toxsci/kfx188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Significant prolonged aryl hydrocarbon receptor (AHR) activation, classically exhibited following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin, can cause a variety of undesirable toxicological effects. Novel pharmaceutical chemistries also have the potential to cause activation of AHR and consequent toxicities in pre-clinical species and man. Previous methods either employed relatively expensive and low-throughput primary hepatocyte dosing with PCR endpoint, or low resolution overexpressing reporter gene assays. We have developed, validated and applied an in vitro microtitre plate imaging-based medium throughput screening assay for the assessment of endogenous species-specific AHR activation potential via detection of induction of the surrogate transcriptional target Cytochrome P450 CYP1A1. Routine testing of pharmaceutical drug development candidate chemistries using this assay can influence the chemical design process and highlight AHR liabilities. This assay should be introduced such that human AHR activation liability is flagged early for confirmatory testing.
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Affiliation(s)
- Martin R Brown
- Discovery Sciences, AstraZeneca R&D Darwin, Cambridge CB4 0WG, UK
| | - Helen Garside
- Discovery Safety & Metabolism, AstraZeneca R&D, Macclesfield, Cheshire SK10 4TG, UK
| | - Emma Thompson
- Discovery Safety & Metabolism, AstraZeneca R&D, Macclesfield, Cheshire SK10 4TG, UK
| | - Saseela Atwal
- Discovery Safety & Metabolism, AstraZeneca R&D, Macclesfield, Cheshire SK10 4TG, UK
| | - Chloe Bean
- AstraZeneca R&D Charnwood, Loughborough, Leics LE11 5RH, UK
| | - Tony Goodall
- AstraZeneca R&D Charnwood, Loughborough, Leics LE11 5RH, UK
| | | | - Mark J Graham
- AstraZeneca R&D Charnwood, Loughborough, Leics LE11 5RH, UK
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18
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Aryl hydrocarbon receptor (AhR) a possible target for the treatment of skin disease. Med Hypotheses 2018; 116:96-100. [PMID: 29857917 DOI: 10.1016/j.mehy.2018.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/21/2018] [Accepted: 05/07/2018] [Indexed: 01/03/2023]
Abstract
Aryl hydrocarbon receptor (AhR) is a transcription factor expressed in all skin cells type. It responds to exogenous and endogenous chemicals by inducing/repressing the expression of several genes with toxic or protective effects in a wide range of species and tissues. In healthy skin, AhR signalling contributes to keratinocytes differentiation, skin barrier function, skin pigmentation, and mediates oxidative stress. In the last years, some studies have shown that AhR seems to be involved in the pathogenesis of some skin diseases, even if the currently available data are contradictory. Indeed, while the blocking the AhR signalling activity could prevent or treat skin cancer, the AhR activation seems to be advantageous for the treatment of inflammatory skin diseases. Therefore, for its multifaceted role in skin diseases, AhR seems to be an attractive therapeutic target. Indeed, recently some molecules have been identified for the prevention of skin cancer and the treatment of inflammatory skin diseases.
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19
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Olp MD, Zhu N, Smith BC. Metabolically Derived Lysine Acylations and Neighboring Modifications Tune the Binding of the BET Bromodomains to Histone H4. Biochemistry 2017; 56:5485-5495. [PMID: 28945351 DOI: 10.1021/acs.biochem.7b00595] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Recent proteomic studies discovered histone lysines are modified by acylations beyond acetylation. These acylations derive from acyl-CoA metabolites, potentially linking metabolism to transcription. Bromodomains bind lysine acylation on histones and other nuclear proteins to influence transcription. However, the extent bromodomains bind non-acetyl acylations is largely unknown. Also unclear are the effects of neighboring post-translational modifications, especially within heavily modified histone tails. Using peptide arrays, binding assays, sucrose gradients, and computational methods, we quantified 10 distinct acylations for binding to the bromodomain and extraterminal domain (BET) family. Four of these acylations (hydroxyisobutyrylation, malonylation, glutarylation, and homocitrullination) had never been tested for bromodomain binding. We found N-terminal BET bromodomains bound acetylated and propionylated peptides, consistent with previous studies. Interestingly, all other acylations inhibited binding of the BET bromodomains to peptides and nucleosomes. To understand how context tunes bromodomain binding, effects of neighboring methylation, phosphorylation, and acylation within histone H4 tails were determined. Serine 1 phosphorylation inhibited binding of the BRD4 N-terminal bromodomain to polyacetylated H4 tails by >5-fold, whereas methylation had no effect. Furthermore, binding of BRDT and BRD4 N-terminal bromodomains to H4K5acetyl was enhanced 1.4-9.5-fold by any neighboring acylation of lysine 8, indicating a secondary H4K8acyl binding site that is more permissive of non-acetyl acylations than previously appreciated. In contrast, C-terminal BET bromodomains exhibited 9.9-13.5-fold weaker binding for polyacylated than for monoacylated H4 tails, indicating the C-terminal bromodomains do not cooperatively bind multiple acylations. These results suggest acyl-CoA levels tune or block recruitment of the BET bromodomains to histones, linking metabolism to bromodomain-mediated transcription.
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Affiliation(s)
- Michael D Olp
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
| | - Nan Zhu
- Stem Cell Biology and Hematopoiesis Program, Blood Research Institute, Blood Center of Wisconsin , Milwaukee, Wisconsin 53226, United States
| | - Brian C Smith
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
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20
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Abstract
How genetic and epigenetic events synergize to generate the oncogenic state is not well understood. In this issue of Cancer Cell, Vaz et al. provide compelling evidence that exposure to chronic cigarette smoke causes progressive epigenetic alterations that prime for key genetic events to drive the development of lung cancer.
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Affiliation(s)
- Susan J Clark
- Epigenetics Research Laboratory, Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; St. Vincent's Clinical School, UNSW Sydney, Sydney, NSW 1466, Australia.
| | - Peter L Molloy
- CSIRO Health and Biosecurity, PO Box 52, North Ryde, NSW 1670, Australia
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21
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Joshi AD, Hossain E, Elferink CJ. Epigenetic Regulation by Agonist-Specific Aryl Hydrocarbon Receptor Recruitment of Metastasis-Associated Protein 2 Selectively Induces Stanniocalcin 2 Expression. Mol Pharmacol 2017; 92:366-374. [PMID: 28696214 DOI: 10.1124/mol.117.108878] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 06/28/2017] [Indexed: 02/06/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates a plethora of target genes. Historically, the AhR has been studied as a regulator of xenobiotic metabolizing enzyme genes, notably cytochrome P4501A1 encoded by CYP1A1, in response to the exogenous prototypical ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). AhR activity depends on its binding to the xenobiotic response element (XRE) in partnership with the AhR nuclear translocator (Arnt). Recent studies identified stanniocalcin 2 (Stc2) as a novel AhR target gene responsive to the endogenous AhR agonist cinnabarinic acid (CA). CA-dependent AhR-XRE-mediated Stc2 upregulation is responsible for cytoprotection against ectoplasmic reticulum/oxidative stress-induced apoptosis both in vitro and in vivo. Significantly, CA but not TCDD induces expression of Stc2 in hepatocytes. In contrast to TCDD, CA is unable to induce the CYP1A1 gene, thus revealing an AhR agonist-specific mutually exclusive dichotomous transcriptional response. Studies reported here provide a mechanistic explanation for this differential response by identifying an interaction between the AhR and the metastasis-associated protein 2 (MTA2). Moreover, the AhR-MTA2 interaction is CA-dependent and results in MTA2 recruitment to the Stc2 promoter, concomitant with agonist-specific epigenetic modifications targeting histone H4 lysine acetylation. The results demonstrate that histone H4 acetylation is absolutely dependent on CA-induced AhR and MTA2 recruitment to the Stc2 regulatory region and induced Stc2 gene expression, which in turn confers cytoprotection to liver cells exposed to chemical insults.
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Affiliation(s)
- Aditya D Joshi
- Department of Pharmacology and Toxicology (A.D.J., C.J.E.) and Sealy Center for Environmental Health and Medicine (E.H., C.J.E.), University of Texas Medical Branch, Galveston, Texas
| | - Ekram Hossain
- Department of Pharmacology and Toxicology (A.D.J., C.J.E.) and Sealy Center for Environmental Health and Medicine (E.H., C.J.E.), University of Texas Medical Branch, Galveston, Texas
| | - Cornelis J Elferink
- Department of Pharmacology and Toxicology (A.D.J., C.J.E.) and Sealy Center for Environmental Health and Medicine (E.H., C.J.E.), University of Texas Medical Branch, Galveston, Texas
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22
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Wright EJ, De Castro KP, Joshi AD, Elferink CJ. Canonical and non-canonical aryl hydrocarbon receptor signaling pathways. CURRENT OPINION IN TOXICOLOGY 2017; 2:87-92. [PMID: 32296737 DOI: 10.1016/j.cotox.2017.01.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Decades of research on the Aryl hydrocarbon Receptor (AhR) has unveiled its involvement in the toxicity of halogenated and polycyclic aromatic hydrocarbons, and a myriad of normal physiological processes. The molecular dissection of AhR biology has centered on a canonical signaling pathway in an effort to mechanistically reconcile the diverse pathophysiological effects of exposure to environmental pollutants. As a consequence, we now know that canonical signaling can explain many but not all of the AhR-mediated effects. Here we describe recent findings that point to non-canonical signaling pathways, and focus on a novel AhR interaction with the Krüppel-like Factor 6 protein responsible for previously un-recognized epigenetic changes in the chromatin affecting gene expression.
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Affiliation(s)
- Eric J Wright
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
| | - Karen Pereira De Castro
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
| | - Aditya D Joshi
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
| | - Cornelis J Elferink
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
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23
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Ren L, Thompson JD, Cheung M, Ngo K, Sung S, Leong S, Chan WK. Selective suppression of the human aryl hydrocarbon receptor function can be mediated through binding interference at the C-terminal half of the receptor. Biochem Pharmacol 2016; 107:91-100. [PMID: 26970402 DOI: 10.1016/j.bcp.2016.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/07/2016] [Indexed: 11/26/2022]
Abstract
The human aryl hydrocarbon receptor is a cytosolic signaling molecule which affects immune response and aberrant cell growth. Canonical signaling of the receptor requires the recruitment of coactivators to the promoter region to remodel local chromatin structure. We predicted that interference of this recruitment would block the aryl hydrocarbon receptor function. To prove that, we employed phage display to identify nine peptides of twelve-amino-acid in length which target the C-terminal half of the human aryl hydrocarbon receptor, including the region where coactivators bind. Eight 12mer peptides, in the form of GFP fusion, suppressed the ligand-dependent transcription of six AHR target genes (cyp1a1, cyp1a2, cyp1b1, ugt1a1, nqo1, and ahrr) in different patterns in Hep3B cells, whereas the AHR antagonist CH-223191 suppressed all these target genes similarly. Three of the 12mer peptides (namely 11-3, 1-7, and 7-3) suppressed the 3MC-induced, CYP1A1-dependent EROD activity and the ROS production caused by benzo[a]pyrene. These 12mer peptides suppressed the AHR function synergistically with CH-223191. In conclusion, we provide evidence that targeting the C-terminal half of the human aryl hydrocarbon receptor is a viable, new approach to selectively block the receptor function.
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Affiliation(s)
- Lina Ren
- Harbin Center for Disease Control and Prevention, Harbin, China
| | - John D Thompson
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Michael Cheung
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Katherine Ngo
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Sarah Sung
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Scott Leong
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - William K Chan
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States.
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