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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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2
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El Amine Z, Mauger JF, Imbeault P. Human Preadipocytes Differentiated under Hypoxia following PCB126 Exposure during Proliferation: Effects on Differentiation, Glucose Uptake and Adipokine Profile. Cells 2023; 12:2326. [PMID: 37759548 PMCID: PMC10527447 DOI: 10.3390/cells12182326] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/09/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Persistent organic pollutants (POPs) accumulation and hypoxia are two factors proposed to adversely alter adipose tissue (AT) functions in the context of excess adiposity. Studies have shown that preadipocytes exposure to dioxin and dioxin-like POPs have the greatest deleterious impact on rodent and immortalized human preadipocyte differentiation, but evidence on human preadipocytes is lacking. Additionally, hypoxia is known to strongly interfere with the dioxin-response pathway. Therefore, we tested the effects of pre-differentiation polychlorinated biphenyl (PCB)126 exposure at 10 µM for 3 days and subsequent differentiation under hypoxia on human subcutaneous adipocytes (hSA) differentiation, glucose uptake and expression of selected metabolism- and inflammation-related genes. Pre-differentiation PCB126 exposure lowered the adenosine triphosphate (ATP) content, glucose uptake and leptin expression of mature adipocytes but had limited effects on differentiation under normoxia (21% O2). Under hypoxia (3% O2), preadipocytes ability to differentiate was significantly reduced as reflected by significant decreased lipid accumulation and downregulation of key adipocyte genes such as peroxisome proliferator-activated receptor gamma (PPARγ) and adiponectin. Hypoxia increased glucose uptake and glucose transporter 1 (GLUT1) expression but abolished the adipocytes insulin response and GLUT4 expression. The expression of pro-inflammatory adipokine interleukin-6 (IL-6) was slightly increased by both PCB126 and hypoxia, while IL-8 expression was significantly increased only following the PCB126-hypoxia sequence. These observations suggest that PCB126 does not affect human preadipocyte differentiation, but does affect the subsequent adipocytes population, as reflected by lower ATP levels and absolute glucose uptake. On the other hand, PCB126 and hypoxia exert additive effects on AT inflammation, an important player in the development of chronic diseases such as type 2 diabetes and cardiovascular diseases.
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Affiliation(s)
- Zeinab El Amine
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (Z.E.A.); (J.-F.M.)
| | - Jean-François Mauger
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (Z.E.A.); (J.-F.M.)
| | - Pascal Imbeault
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (Z.E.A.); (J.-F.M.)
- Institut du savoir Montfort, Hôpital Montfort, Ottawa, ON K1K 0T2, Canada
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Ullah K, Ai L, Humayun Z, Wu R. Targeting Endothelial HIF2α/ ARNT Expression for Ischemic Heart Disease Therapy. Biology (Basel) 2023; 12:995. [PMID: 37508425 PMCID: PMC10376750 DOI: 10.3390/biology12070995] [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] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/07/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023]
Abstract
Ischemic heart disease (IHD) is a major cause of mortality and morbidity worldwide, with novel therapeutic strategies urgently needed. Endothelial dysfunction is a hallmark of IHD, contributing to its development and progression. Hypoxia-inducible factors (HIFs) are transcription factors activated in response to low oxygen levels, playing crucial roles in various pathophysiological processes related to cardiovascular diseases. Among the HIF isoforms, HIF2α is predominantly expressed in cardiac vascular endothelial cells and has a key role in cardiovascular diseases. HIFβ, also known as ARNT, is the obligate binding partner of HIFα subunits and is necessary for HIFα's transcriptional activity. ARNT itself plays an essential role in the development of the cardiovascular system, regulating angiogenesis, limiting inflammatory cytokine production, and protecting against cardiomyopathy. This review provides an overview of the current understanding of HIF2α and ARNT signaling in endothelial cell function and dysfunction and their involvement in IHD pathogenesis. We highlight their roles in inflammation and maintaining the integrity of the endothelial barrier, as well as their potential as therapeutic targets for IHD.
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Affiliation(s)
- Karim Ullah
- Section of Cardiology, Department of Medicine, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
| | - Lizhuo Ai
- Section of Cardiology, Department of Medicine, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
- The Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Zainab Humayun
- Section of Cardiology, Department of Medicine, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
| | - Rongxue Wu
- Section of Cardiology, Department of Medicine, Biological Sciences Division, University of Chicago, Chicago, IL 60637, USA
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4
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Motta S, Bonati L. TCDD-Induced Allosteric Perturbation of the AhR: ARNT Binding to DNA. Int J Mol Sci 2023; 24:ijms24119339. [PMID: 37298290 DOI: 10.3390/ijms24119339] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the biological and toxicological effects of structurally diverse chemicals, including halogenated aromatic hydrocarbons. In this work, we investigate the effects of the binding of the AhR prototypical ligand, TCDD, on the stability of the AhR:ARNT complex, as well as the mechanisms by which ligand-induced perturbations propagate to the DNA recognition site responsible for gene transcription. To this aim, a reliable structural model of the overall quaternary structure of the AhR:ARNT:DRE complex is proposed, based on homology modelling. The model shows very good agreement with a previous one and is supported by experimental evidence. Moreover, molecular dynamics simulations are performed to compare the dynamic behaviour of the AhR:ARNT heterodimer in the presence or absence of the TCDD. Analysis of the simulations, performed by an unsupervised machine learning method, shows that TCDD binding to the AhR PASB domain influences the stability of several inter-domain interactions, in particular at the PASA-PASB interface. The inter-domain communication network suggests a mechanism by which TCDD binding allosterically stabilizes the interactions at the DNA recognition site. These findings may have implications for the comprehension of the different toxic outcomes of AhR ligands and drug design.
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Affiliation(s)
- Stefano Motta
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Laura Bonati
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, 20126 Milan, Italy
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Rudyak SG, Usakin LA, Tverye EA, Robertson ED, Panteleyev AA. Aryl hydrocarbon receptor is regulated via multiple mechanisms in human keratinocytes. Toxicol Lett 2023:S0378-4274(23)00185-6. [PMID: 37217010 DOI: 10.1016/j.toxlet.2023.05.007] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 05/11/2023] [Accepted: 05/19/2023] [Indexed: 05/24/2023]
Abstract
Aryl hydrocarbon receptor (AhR) is a basic helix-loop-helix transcription factor activated by polycyclic aromatic hydrocarbons of synthetic and natural origin. While a number of novel AhR ligands have been recently identified, little is known about their possible influence on AhR levels and stability. We used western blot, qRT-PCR and immunocytochemistry to determine the effects of AhR ligands on AhR expression in N-TERT (N-TERT1) immortalized human keratinocytes, and immunohistochemistry to assess patterns of AhR expression in human and mouse skin and skin appendages. While AhR was highly expressed in cultured keratinocytes and in the skin, it was found primarily in the cytoplasm, but not in the nucleus, suggesting its inactivity. At the same time, treatment of N-TERT cells with proteasomal inhibitor MG132 and eventual inhibition of AhR degradation resulted in nuclear AhR accumulation. Treatment of keratinocytes with AhR ligands such as TCDD, FICZ, caused near-complete disappearance of AhR, and treatment with I3C resulted in substantially diminished level of AhR possibly due to ligand-induced AhR degradation. The AhR decay was blocked by proteasome inhibition, indicating degradation-based mechanism of regulation. Additionally, AhR decay was blocked by ligand-selective AhR antagonist CH223191, implying substrate-induced mechanism of degradation. Furthermore, degradation of AhR was blocked in N-TERT cells with knockdown of AhR dimerization partner ARNT (HIF1β), suggesting that ARNT is required for AhR proteolysis. However, addition of hypoxia mimetics (HIF1 pathway activators) CoCl2 and DMOG had only minor effects on degradation of AhR. Additionally, inhibition of HDACs with Trichostatin A resulted in enhanced expression of AhR in both untreated and ligand-treated cells. These results demonstrate that in immortalized epidermal keratinocytes AhR is primarily regulated post-translationally via proteasome-mediated degradation, and suggest potential means to manipulate AhR levels and signaling in the skin. Overall, the AhR is regulated via multiple mechanisms, including proteasomal ligand- and ARNT-dependent degradation, and transcriptional regulation by HDACs, implying complex system of balancing its expression and protein stability.
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Affiliation(s)
- S G Rudyak
- Pirogov Russian National Research Medical University, Moscow, Russia.
| | - L A Usakin
- National Research Center "Kurchatov Institute", Moscow, Russia
| | - E A Tverye
- National Research Center "Kurchatov Institute", Moscow, Russia
| | | | - A A Panteleyev
- National Research Center "Kurchatov Institute", Moscow, Russia; A.V. Vishnevsky National Medical Research Center of Surgery, Moscow, Russia.
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Ceranski AK, Carreño-Gonzalez MJ, Ehlers AC, Colombo MV, Cidre-Aranaz F, Grünewald TGP. Hypoxia and HIFs in Ewing sarcoma: new perspectives on a multi-facetted relationship. Mol Cancer 2023; 22:49. [PMID: 36915100 PMCID: PMC10010019 DOI: 10.1186/s12943-023-01750-w] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 02/20/2023] [Indexed: 03/16/2023] Open
Abstract
Hypoxia develops during the growth of solid tumors and influences tumoral activity in multiple ways. Low oxygen tension is also present in the bone microenvironment where Ewing sarcoma (EwS) - a highly aggressive pediatric cancer - mainly arises. Hypoxia inducible factor 1 subunit alpha (HIF-1-a) is the principal molecular mediator of the hypoxic response in cancer whereas EWSR1::FLI1 constitutes the oncogenic driver of EwS. Interaction of the two proteins has been shown in EwS. Although a growing body of studies investigated hypoxia and HIFs in EwS, their precise role for EwS pathophysiology is not clarified to date. This review summarizes and structures recent findings demonstrating that hypoxia and HIFs play a role in EwS at multiple levels. We propose to view hypoxia and HIFs as independent protagonists in the story of EwS and give a perspective on their potential clinical relevance as prognostic markers and therapeutic targets in EwS treatment.
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Affiliation(s)
- A Katharina Ceranski
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Martha J Carreño-Gonzalez
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Anna C Ehlers
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Maria Vittoria Colombo
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,Regenerative Medicine Technologies Laboratory, Laboratories for Translational Research (LRT), Ente Ospedaliero Cantonale (EOC), Via F. Chiesa 5, CH-6500, Bellinzona, Switzerland.,Department of Surgery, Service of Orthopaedics and Traumatology, EOC, Lugano, Switzerland.,Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico Di Milano, Via Mancinelli 7, 20131, Milan, Italy
| | - Florencia Cidre-Aranaz
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Thomas G P Grünewald
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany. .,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. .,Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany.
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Wang X, Bao J, Bi Y, Hu W, Zhang L. Polymorphism, Expression, and Structure Analysis of a Key Gene ARNT in Sheep ( Ovis aries). Biology (Basel) 2022; 11:biology11121795. [PMID: 36552304 PMCID: PMC9774921 DOI: 10.3390/biology11121795] [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] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/28/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Growth traits are influential factors that significantly affects the development of the sheep industry. A previous TMT proteomic analysis found that a key protein in the HIF signaling pathway, ARNT, may influence embryonic skeletal muscle growth and development in sheep. The purpose of this study was to better understand the association between the polymorphisms of ARNT and growth traits of sheep, and the potential function of ARNT. Real-time qPCR (qRT-PCR) of ARNT was carried out to compare its expression in different developmental stages of the muscle tissues and primary myoblasts in the Hu, Chinese merino, and Gangba sheep. The genetic variance of ARNT was detected using the Illumina Ovine SNP 50 K and 600 K BeadChip in the Hu and Ujimqin sheep populations, respectively. The CDS sequence of the ARNT gene was cloned in the Hu sheep using PCR technology. Finally, bioinformatic analytical methods were applied to characterize the genes and their hypothetical protein products. The qRT-PCR results showed that the ARNT gene was expressed significantly in the Chinese merino embryo after 85 gestation days (D85) (p < 0.05). Additionally, after the sheep were born, the expression of ARNT was significant at the weaning stage of the Hu sheep (p < 0.01). However, there was no difference in the Gangba sheep.In addition, six SNP loci were screened using 50 K and 600 K BeadChip. We found a significant association between rs413597480 A > G and the Hu sheep weight at weaning and backfat thickness in the 5-month-old sheep (p < 0.05), and four SNP loci (rs162298018 G > C, rs159644025 G > A, rs421351865 G > A, and rs401758103 A > G) were also associated with growth traits in the Ujimqin sheep (p < 0.05). Interestingly, we found that a G > C mutation at 1948 bp in the cloned ARNT CDS sequence of the Hu sheep was the same locus mutation as rs162298018 G > C identified using the 600 K BeadChip, which resulted in a nonconservative missense point mutation, leading to a change from proline to alanine and altering the number of DNA, protein-binding sites, and the α-helix of the ARNT protein. There was a strong linkage disequilibrium between rs162298018 G > C and rs159644025 G > A, and the ARNT protein was conserved among the goat, Hu sheep, and Texel sheep. And, we propose that a putative molecular marker for growth and development in sheep may be the G > C mutation at 1948 bp in the CDS region of the ARNT gene. Our study systematically analyzed the expression, structure, and function of the ARNT gene and its encoded proteins in sheep. This provides a basis for future studies of the regulatory mechanisms of the ARNT gene.
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Affiliation(s)
- Xinyue Wang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jingjing Bao
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yazhen Bi
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- College of Animal Science and Technology, Qingdao Agriculture University, Qingdao 266109, China
| | - Wenping Hu
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Li Zhang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: ; Tel.: +86-010-6281-6002
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Liu B, Chen H. Identification and Functional Characterization of the Transcription Factors AhR/ ARNT in Dendroctonus armandi. Cells 2022; 11. [PMID: 36497113 DOI: 10.3390/cells11233856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) belong to the bHLH-PAS (basic Helix-Loop-Helix-Period/ARNT/Single-minded) family of transcription factors, which participate in the sensing and transmitting stimuli of exogenous and endogenous chemical substances, and subsequently activates genes transcription involved in various detoxification and physiological functions. However, they have not been identified in Dendroctonus armandi, and their roles in the detoxification metabolism are unclear. In the present study, AhR and ARNT of D. armandi were characterized. Spatiotemporal expression profiling indicated that DaAhR and DaARNT were highly expressed in the adult and larval stages of D. armandi and mainly expressed in the midgut and Malpighian tubules of adults. Additionally, the expression of DaAhR and DaARNT significantly increased after exposure to (-)-𝛽-pinene, (+)-3-carene, and (±)-limonene. Silencing DaAhR and DaARNT increased the susceptibility of D. armandi to (-)-𝛽-pinene, (+)-3-carene, and (±)-limonene, and the activities of detoxification enzyme were also remarkably reduced. Moreover, DaCYP6DF1 and DaGSTs2 were significantly down-regulated after injections of dsAhR and dsARNT in the male and female adults, with the expression of DaCYP6DF1 decreasing by higher than 70%. The present study revealed that the transcription factors AhR and ARNT of D. armandi were induced by terpenoids and participated in the regulation of DaCYP6DF1 expression, which was associated with D. armandi's susceptibility to (-)-𝛽-pinene and (±)-limonene. These results may provide a theoretical basis for the integrated control of D. armandi and improve our comprehension of insect toxicology.
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Cooper AM, Nutter CA, Kuyumcu-Martinez MN, Wright CW. Alternative Splicing of the Aryl Hydrocarbon Receptor Nuclear Translocator ( ARNT) Is Regulated by RBFOX2 in Lymphoid Malignancies. Mol Cell Biol 2022; 42:e0050321. [PMID: 35404107 DOI: 10.1128/mcb.00503-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Aberrant alternative splicing (AS) of pre-mRNAs promotes the development and proliferation of cancerous cells. Accordingly, we had previously observed higher levels of the aryl hydrocarbon receptor nuclear translocator (ARNT) spliced variant isoform 1 in human lymphoid malignancies compared to that in normal lymphoid cells, which is a consequence of increased inclusion of alternative exon 5. ARNT is a transcription factor that has been implicated in the survival of various cancers. Notably, we found that ARNT isoform 1 promoted the growth and survival of lymphoid malignancies, but the regulatory mechanism controlling ARNT AS is unclear. Here, we report cis- and trans-regulatory elements which are important for the inclusion of ARNT exon 5. Specifically, we identified recognition motifs for the RNA-binding protein RBFOX2, which are required for RBFOX2-mediated exon 5 inclusion. RBFOX2 upregulation was observed in lymphoid malignancies, correlating with the observed increase in ARNT exon 5 inclusion. Moreover, suppression of RBFOX2 significantly reduced ARNT isoform 1 levels and cell growth. These observations reveal RBFOX2 as a critical regulator of ARNT AS in lymphoid malignancies and suggest that blocking the ARNT-specific RBFOX2 motifs to decrease ARNT isoform 1 levels is a viable option for targeting the growth of lymphoid malignancies.
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Bourner LA, Muro I, Cooper AM, Choudhury BK, Bailey AO, Russell WK, Khanipov K, Golovko G, Wright CW. AhR promotes phosphorylation of ARNT isoform 1 in human T cell malignancies as a switch for optimal AhR activity. Proc Natl Acad Sci U S A 2022; 119:e2114336119. [PMID: 35290121 DOI: 10.1073/pnas.2114336119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The aryl hydrocarbon receptor nuclear translocator (ARNT) is a transcription factor present in immune cells as a long and short isoform, referred to as isoforms 1 and 3, respectively. However, investigation into potential ARNT isoform–specific immune functions is lacking despite the well-established heterodimerization requirement of ARNT with, and for the activity of, the aryl hydrocarbon receptor (AhR), a critical mediator of immune homeostasis. Here, using global and targeted transcriptomics analyses, we show that the relative ARNT isoform 1:3 ratio in human T cell lymphoma cells dictates the amplitude and direction of AhR target gene regulation. Specifically, shifting the ARNT isoform 1:3 ratio lower by suppressing isoform 1 enhances, or higher by suppressing isoform 3 abrogates, AhR responsiveness to ligand activation through preprograming a cellular genetic background that directs explicit gene expression patterns. Moreover, the fluctuations in gene expression patterns that accompany a decrease or increase in the ARNT isoform 1:3 ratio are associated with inflammation or immunosuppression, respectively. Molecular studies identified the unique casein kinase 2 (CK2) phosphorylation site within isoform 1 as an essential parameter to the mechanism of ARNT isoform–specific regulation of AhR signaling. Notably, CK2-mediated phosphorylation of ARNT isoform 1 is dependent on ligand-induced AhR nuclear translocation and is required for optimal AhR target gene regulation. These observations reveal ARNT as a central modulator of AhR activity predicated on the status of the ARNT isoform ratio and suggest that ARNT-based therapies are a viable option for tuning the immune system to target immune disorders.
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Abstract
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is a member of the PER-ARNT-SIM superfamily of environmental sensors. This receptor has been a molecule of interest for many years in the field of toxicology, as it was originally discovered to mediate the toxic effects of certain environmental pollutants like benzo(a)pyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin. While all animals express this protein, there is naturally occurring variability in receptor size and responsiveness to ligand. This naturally occurring variation, particularly in mice, has been an essential tool in the discovery and early characterization of the AHR. Genetic models including congenic mice and induced mutations at the Ahr locus have proven invaluable in further understanding the role of the AHR in adaptive metabolism and TCDD-induced toxicity. The creation and examination of Ahr null mice revealed an important physiological role for the AHR in vascular and hepatic development and mediation of the immune system. In this review, we attempt to provide an overview to many of the AHR models that have aided in the understanding of AHR biology thus far. We describe the naturally occurring polymorphisms, congenic models, induced mutations at the Ahr locus and at the binding partner Ah Receptor Nuclear Translocator and chaperone, Ah receptor associated 9 loci in mice, with a brief description of naturally occurring and induced mutations in rats.
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Affiliation(s)
- Rachel H Wilson
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Christopher A Bradfield
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.,Biotechnology Center, University of Wisconsin, Madison, WI, USA
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Bowlin A, Roys H, Wanjala H, Bettadapura M, Venugopal G, Surma J, Simon MC, Weinkopff T. Hypoxia-Inducible Factor Signaling in Macrophages Promotes Lymphangiogenesis in Leishmania major Infection. Infect Immun 2021; 89:e0012421. [PMID: 34031127 DOI: 10.1128/IAI.00124-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Vascular remodeling is a phenomenon seen in the cutaneous lesions formed during infection with Leishmania parasites. Within the lesion, Leishmania major infection leads to the infiltration of inflammatory cells, including macrophages, and is associated with hypoxic conditions and lymphangiogenesis in the local site. This low-oxygen environment is concomitant with the expression of hypoxic inducible factors (HIFs), which initiate the expression of vascular endothelial growth factor-A (VEGF-A) in macrophages during the infection. Here, we found that macrophage hypoxia is elevated in the skin, and the HIF target Vegfa is preferentially expressed at the site of infection. Further, transcripts indicative of both HIF-1α and HIF-2α activation were increased at the site of infection. Given that HIF mediates VEGF-A and that VEGF-A/VEGFR-2 signaling induces lymphangiogenesis, we wanted to investigate the link between myeloid HIF activation and lymphangiogenesis during L. major infection. We show that myeloid aryl hydrocarbon receptor nuclear translocator (ARNT)/HIF/VEGF-A signaling promotes lymphangiogenesis (the generation of newly formed vessels within the local lymphatic network), which helps resolve the lesion by draining away inflammatory cells and fluid. Concomitant with impaired lymphangiogenesis, we find the deletion of myeloid ARNT/HIF signaling leads to an exacerbated inflammatory response associated with a heightened CD4+ Th1 immune response following L. major infection. Altogether, our data suggest that VEGF-A-mediated lymphangiogenesis occurs through myeloid ARNT/HIF activation following Leishmania major infection and this process is critical in limiting immunopathology.
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Wang Y, Jin R, Liu C, Gao Y, Deng X, Wan H, Li J. Functional characterization of the transcription factors AhR and ARNT in Nilaparvata lugens. Pestic Biochem Physiol 2021; 176:104875. [PMID: 34119220 DOI: 10.1016/j.pestbp.2021.104875] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/09/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
In the present study, the aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) of Nilaparvata lugens were cloned and identified. The NlAhR and NlARNT expression levels significantly increased after imidacloprid, etofenprox and isoprocarb treatments. Knockdowns of NlAhR and NlARNT increased the susceptibility of N. lugens to imidacloprid, etofenprox and isoprocarb, and the detoxification enzyme activities were also significantly decreased. In addition, NlCYP301A1, NlGSTt1 and NlCarE7 were significantly down-regulated after injections of dsNlAhR and dsNlARNT, with the NlCarE7 expression decreasing by greater than 80%. Moreover, after knocking down NlCarE7, the susceptibility of N. lugens to etofenprox and isoprocarb significantly increased. Both NlAhR and NlARNT bound the NlCarE7 promoter and significantly enhanced the transcriptional activity. Our research revealed the functional roles of transcription factors NlAhR and NlARNT in the detoxification metabolism of N. lugens. The results provide a theoretical basis for the pest management and comprehensive control of N. lugens and increase our knowledge of insect toxicology.
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Affiliation(s)
- Yue Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Ruoheng Jin
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Chaoya Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yuanyuan Gao
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Xiaoqian Deng
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Hu Wan
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Jianhong Li
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
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Nguyen T, Zheng M, Knapp M, Sladojevic N, Zhang Q, Ai L, Harrison D, Chen A, Sitikov A, Shen L, Gonzalez FJ, Zhao Q, Fang Y, Liao JJK, Wu R. Endothelial Aryl Hydrocarbon Receptor Nuclear Translocator Mediates the Angiogenic Response to Peripheral Ischemia in Mice With Type 2 Diabetes Mellitus. Front Cell Dev Biol 2021; 9:691801. [PMID: 34179020 PMCID: PMC8222825 DOI: 10.3389/fcell.2021.691801] [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: 04/07/2021] [Accepted: 05/17/2021] [Indexed: 11/13/2022] Open
Abstract
Hypoxia-inducible factors (HIFs) are the master regulators of angiogenesis, a process that is impaired in patients with diabetes mellitus (DM). The transcription factor aryl hydrocarbon receptor nuclear translocator (ARNT, also known as HIF1β) has been implicated in the development and progression of diabetes. Angiogenesis is driven primarily by endothelial cells (ECs), but both global and EC-specific loss of ARNT-cause are associated with embryonic lethality. Thus, we conducted experiments in a line of mice carrying an inducible, EC-specific ARNT-knockout mutation (Arnt Δ EC, ERT2) to determine whether aberrations in ARNT expression might contribute to the vascular deficiencies associated with diabetes. Mice were first fed with a high-fat diet to induce diabetes. Arnt Δ EC, ERT2 mice were then adminstrated with oral tamoxifen to disrupt Arnt and peripheral angiogenesis was evaluated by using laser-Doppler perfusion imaging to monitor blood flow after hindlimb ischemia. The Arnt Δ EC, ERT2 mice had impaired blood flow recovery under both non-diabetic and diabetic conditions, but the degree of impairment was greater in diabetic animals. In addition, siRNA-mediated knockdown of ARNT activity reduced measurements of tube formation, and cell viability in human umbilical vein endothelial cells (HUVECs) cultured under high-glucose conditions. The Arnt Δ EC, ERT2 mutation also reduced measures of cell viability, while increasing the production of reactive oxygen species (ROS) in microvascular endothelial cells (MVECs) isolated from mouse skeletal muscle, and the viability of Arnt Δ EC, ERT2 MVECs under high-glucose concentrations increased when the cells were treated with an ROS inhibitor. Collectively, these observations suggest that declines in endothelial ARNT expression contribute to the suppressed angiogenic phenotype in diabetic mice, and that the cytoprotective effect of ARNT expression in ECs is at least partially mediated by declines in ROS production.
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Affiliation(s)
- Tu Nguyen
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Mei Zheng
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Maura Knapp
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Nikola Sladojevic
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Qin Zhang
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Lizhuo Ai
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Devin Harrison
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Anna Chen
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Albert Sitikov
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Le Shen
- Section of General Surgery, Department of Surgery, University of Chicago, Chicago, IL, United States
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Qiong Zhao
- Division of Cardiology, Department of Medicine, Inova Heart and Vascular Institute, Annandale, VA, United States
| | - Yun Fang
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - James J. K. Liao
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Rongxue Wu
- Biological Sciences Division – Cardiology, Department of Medicine, University of Chicago, Chicago, IL, United States
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15
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Xu X, Dikiy I, Evans MR, Marcelino LP, Gardner KH. Fragile protein folds: Sequence and environmental factors affecting the equilibrium of two interconverting, stably folded protein conformations. Magn Reson (Gott) 2021; 2:63-76. [PMID: 35603043 PMCID: PMC9119131 DOI: 10.5194/mr-2-63-2021] [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] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Recent research on fold-switching metamorphic proteins has revealed some notable exceptions to Anfinsen's hypothesis of protein folding. We have previously described how a single point mutation can enable a well-folded protein domain, one of the two PAS (Per-ARNT-Sim) domains of the human ARNT (aryl hydrocarbon receptor nuclear translocator) protein, to interconvert between two conformers related by a slip of an internal β-strand. Using this protein as a test case, we advance the concept of a "fragile fold," a protein fold that can reversibly rearrange into another fold that differs by a substantial number of hydrogen bonds, entailing reorganization of single secondary structure elements to more drastic changes seen in metamorphic proteins. Here we use a battery of biophysical tests to examine several factors affecting the equilibrium between the two conformations of the switching ARNT PAS-B Y456T protein. Of note, we find that factors which impact the HI loop preceding the shifted Iβ-strand affect both the equilibrium levels of the two conformers and the denatured state which links them in the interconversion process. Finally, we describe small molecules that selectively bind to and stabilize the wildtype conformation of ARNT PAS-B. These studies form a toolkit for studying fragile protein folds and could enable ways to modulate the biological functions of such fragile folds, both in natural and engineered proteins.
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Affiliation(s)
- Xingjian Xu
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, NY, USA
- Ph.D. Program in Biochemistry, The Graduate Center, CUNY, New York, NY, USA
| | - Igor Dikiy
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, NY, USA
- Current address: Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Matthew R Evans
- Current address: Acclaim Physician Group, Inc. Fort Worth, TX, USA
| | - Leandro P Marcelino
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, NY, USA
- Department of Chemistry and Biochemistry, City College of New York, New York, NY, USA
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, NY, USA
- Department of Chemistry and Biochemistry, City College of New York, New York, NY, USA
- Biochemistry, Chemistry and Biology Ph.D. Programs, The Graduate Center, CUNY, New York, NY, USA
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Al Hanjori AS, Alshaer W, Anati B, Wehaibi S, Zihlif M. Studying Antitumor Effects of Sirna Gene Silencing of some Metabolic Genes in Pancreatic Ductal Adenocarcinoma. Curr Mol Pharmacol 2020; 14:604-619. [PMID: 33045974 DOI: 10.2174/1874467213666201012162250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 05/12/2020] [Revised: 08/20/2020] [Accepted: 08/24/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Earlier diagnosis and advances in treatment strategies have increased the average survival of cancer patients over the last decades. Despite the increased number of new anti-neoplastic agents, there has been no adequate therapy for intricate malignancies such as pancreatic cancer. Cancer metabolism is the main building block standing behind cancer promotion and progression even in the presence of a harsh environment. Targeting metabolic pathways, such as glycolysis and pentose phosphate pathway, is regarded as a promising new strategy for cancer treatment. OBJECTIVE The current study is to investigate the effect of knocking-down pancreatic cancer glycolytic and pentose phosphate pathway's regulators (HIF-1α, ARNT, PFKFB4, and RBKS), on cell's viability and resistance to gemcitabine and doxorubicin, using small interference RNA. METHODOLOGY The human pancreatic ductal adenocarcinoma cell line, Panc-1, was used to study the anti-proliferative activity of targeting HIF-1α, ARNT, PFKFB4, and RBKS mRNAs by transfection with small interference RNAs, each one alone and in combination. The transfected cells were also treated with doxorubicin and gemcitabine to study the relationship between the concerned genes and the resistance of Panc-1 cells to these drugs. The effect on cell proliferation was determined using a colorimetric assay and Inhibitory Concentration (IC50) calculation. A cross-talk study was done to investigate the silencing effect of one of the above genes on the expression of others using Real Time-Polymerase Chain Reaction. RESULTS In vitro transfection with small interference-RNAs, siHIF-1α, siPFKFB4, and siARNT decreased tumor cell proliferation with a maximum effect shown with siPFKFB4; but there was no anti-proliferative effect with RBKS silencing. suppression of transcription of HIF-1α, ARNT, PFKFB4, and RBKS sensitize pancreatic cancer cells, Panc-1, to doxorubicin and gemcitabine. CONCLUSION This study demonstrated the major tumor promoting and progressive effects of PFKFB4, while HIF-1α and ARNT had modulator effects in pancreatic cancer cells (Panc-1). RBKS had a chemo-resistant role justifying its enhanced expression in Panc-1 cells, but not a proliferative one. Silencing of all genes of interest decreased doxorubicin and gemcitabine's resistance and improved the antitumor effect of doxorubicin and gemcitabine in the pancreatic cancer cell line, Panc-1.
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Affiliation(s)
- Ahmad Sada Al Hanjori
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman. Jordan
| | - Walhan Alshaer
- Cell Therapy Center, The University of Jordan, Amman. Jordan
| | - Bayan Anati
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman. Jordan
| | - Suha Wehaibi
- Cell Therapy Center, The University of Jordan. Jordan
| | - Malek Zihlif
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman. Jordan
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Kumar P, Yadav M, Verma K, Dixit R, Singh J, Tiwary SK, Narayan G, Dixit VK. Expression analysis of aryl hydrocarbon receptor repressor (AHRR) gene in gallbladder cancer. Saudi J Gastroenterol 2020; 27:54-59. [PMID: 32801256 PMCID: PMC8083244 DOI: 10.4103/sjg.sjg_213_20] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND The aryl hydrocarbon receptor repressor (AHRR), a member of the growing superfamily, is a basic helix-loop-helix/PerAHR nuclear translocator (ARNT)-Sim (bHLH-PAS) protein. AHRR has been proposed to function as a putative new tumor suppressor gene based on studies in multiple types of human cancers. This current study aims to investigate AHHR expression and its prognostic significance in gallbladder cancer. METHODS The study includes 48 gallbladder cancer and 34 chronic cholecystitis cases as controls. The expression level of AHRR was analyzed by using semi-quantitative PCR and immunohistochemical staining. The results were correlated with different clinical parameters. RESULTS We demonstrate that the expression of AHRR is significantly down-regulated in gallbladder cancer tissue samples as compared to that in chronic cholecystitis tissue samples by reverse transcriptase PCR (RT-PCR) (P = 0.017) and immunohistochemistry analysis (P = 0.002). Interestingly, our RT-PCR data revealed that AHRR mRNA expression is frequently down-regulated (45.8%; 22/48) in cases as compared to 14.7% (5/34) in controls. Similarly, immunohistochemical analysis data show significant down-regulation of AHRR expression in 77.1% (37/48) of gallbladder cancer cases than 44.1% (15/34) in controls (P < 0.017). Reduced mRNA and protein expression is significantly associated with advanced T-stage (P = 0.001), histological differentiation (P = 0.001), and tumors with nodal metastasis (P = 0.001). Decreased expression of AHRR is significantly associated with poor prognosis in gallbladder cancer patients. CONCLUSION In conclusion, the present study suggests that low AHRR expression may be critical in gallbladder cancer development. Our data suggests that AHRR may act as a tumor suppressor gene and its expression profile may be useful as a diagnostic marker in gallbladder cancer.
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Affiliation(s)
- Puneet Kumar
- Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India,Address for correspondence: Prof. Puneet Kumar, Professor and Head, Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi - 221 005, Uttar Pradesh, India. E-mail:
| | - Manoj Yadav
- Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Khushi Verma
- Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Ruhi Dixit
- Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Juhi Singh
- Department of Gastroenterology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Satyendra K Tiwary
- Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Gopeshwar Narayan
- Department of Molecular and Human Genetics, Faculty of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - V K Dixit
- Department of Gastroenterology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
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18
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Brigidi GS, Hayes MGB, Delos Santos NP, Hartzell AL, Texari L, Lin PA, Bartlett A, Ecker JR, Benner C, Heinz S, Bloodgood BL. Genomic Decoding of Neuronal Depolarization by Stimulus-Specific NPAS4 Heterodimers. Cell 2020; 179:373-391.e27. [PMID: 31585079 DOI: 10.1016/j.cell.2019.09.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [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: 03/02/2019] [Revised: 07/22/2019] [Accepted: 09/04/2019] [Indexed: 12/14/2022]
Abstract
Cells regulate gene expression in response to salient external stimuli. In neurons, depolarization leads to the expression of inducible transcription factors (ITFs) that direct subsequent gene regulation. Depolarization encodes both a neuron's action potential (AP) output and synaptic inputs, via excitatory postsynaptic potentials (EPSPs). However, it is unclear if distinct types of electrical activity can be transformed by an ITF into distinct modes of genomic regulation. Here, we show that APs and EPSPs in mouse hippocampal neurons trigger two spatially segregated and molecularly distinct induction mechanisms that lead to the expression of the ITF NPAS4. These two pathways culminate in the formation of stimulus-specific NPAS4 heterodimers that exhibit distinct DNA binding patterns. Thus, NPAS4 differentially communicates increases in a neuron's spiking output and synaptic inputs to the nucleus, enabling gene regulation to be tailored to the type of depolarizing activity along the somato-dendritic axis of a neuron.
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Affiliation(s)
- G Stefano Brigidi
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Michael G B Hayes
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Nathaniel P Delos Santos
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA; Department of Biomedical Informatics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Andrea L Hartzell
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA; Neuroscience Graduate Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Lorane Texari
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Pei-Ann Lin
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA; Neuroscience Graduate Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Anna Bartlett
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Joseph R Ecker
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, La Jolla, CA 92093, USA
| | - Christopher Benner
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Sven Heinz
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA
| | - Brenda L Bloodgood
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA.
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D’Ignazio L, Shakir D, Batie M, Muller HA, Rocha S. HIF-1β Positively Regulates NF-κB Activity via Direct Control of TRAF6. Int J Mol Sci 2020; 21:ijms21083000. [PMID: 32344511 PMCID: PMC7216149 DOI: 10.3390/ijms21083000] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022] Open
Abstract
NF-κB signalling is crucial for cellular responses to inflammation but is also associated with the hypoxia response. NF-κB and hypoxia inducible factor (HIF) transcription factors possess an intense molecular crosstalk. Although it is known that HIF-1α modulates NF-κB transcriptional response, very little is understood regarding how HIF-1β contributes to NF-κB signalling. Here, we demonstrate that HIF-1β is required for full NF-κB activation in cells following canonical and non-canonical stimuli. We found that HIF-1β specifically controls TRAF6 expression in human cells but also in Drosophila melanogaster. HIF-1β binds to the TRAF6 gene and controls its expression independently of HIF-1α. Furthermore, exogenous TRAF6 expression is able to rescue all of the cellular phenotypes observed in the absence of HIF-1β. These results indicate that HIF-1β is an important regulator of NF-κB with consequences for homeostasis and human disease.
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Affiliation(s)
- Laura D’Ignazio
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK;
- The Lieber Institute for Brain Development, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Dilem Shakir
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; (D.S.); (M.B.)
| | - Michael Batie
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; (D.S.); (M.B.)
| | - H. Arno Muller
- Developmental Genetics Unit, Institute of Biology, University of Kassel, 34132 Kassel, Germany;
| | - Sonia Rocha
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; (D.S.); (M.B.)
- Correspondence: ; Tel.: +44-(0)151-794-9084
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20
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Soshilov AA, Motta S, Bonati L, Denison MS. Transitional States in Ligand-Dependent Transformation of the Aryl Hydrocarbon Receptor into Its DNA-Binding Form. Int J Mol Sci 2020; 21:E2474. [PMID: 32252465 DOI: 10.3390/ijms21072474] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/20/2020] [Accepted: 03/30/2020] [Indexed: 01/03/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the biological and toxicological effects of an AhR lacking the entire PASB structurally diverse chemicals, including halogenated aromatic hydrocarbons. Ligand-dependent transformation of the AhR into its DNA binding form involves a ligand-dependent conformational change, heat shock protein 90 (hsp90), dissociation from the AhR complex and AhR dimerization with the AhR nuclear translocator (ARNT) protein. The mechanism of AhR transformation was examined using mutational approaches and stabilization of the AhR:hsp90 complex with sodium molybdate. Insertion of a single mutation (F281A) in the hsp90-binding region of the AhR resulted in its constitutive (ligand-independent) transformation/DNA binding in vitro. Mutations of AhR residues within the Arg-Cys-rich region (R212A, R217A, R219A) and Asp371 (D371A) impaired AhR transformation without a significant effect on ligand binding. Stabilization of AhR:hsp90 binding with sodium molybdate decreased transformation/DNA binding of the wild type AhR but had no effect on constitutively active AhR mutants. Interestingly, transformation of the AhR in the presence of molybdate allowed detection of an intermediate transformation ternary complex containing hsp90, AhR, and ARNT. These results are consistent with a stepwise transformation mechanism in which binding of ARNT to the liganded AhR:hsp90 complex results in a progressive displacement of hsp90 and conversion of the AhR into its high affinity DNA binding form. The available molecular insights into the signaling mechanism of other Per-ARNT-Sim (PAS) domains and structural information on hsp90 association with other client proteins are consistent with the proposed transformation mechanism of the AhR.
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21
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Ramos-García NA, Orozco-Ibarra M, Estudillo E, Elizondo G, Gómez Apo E, Chávez Macías LG, Sosa-Ortiz AL, Torres-Ramos MA. Aryl Hydrocarbon Receptor in Post-Mortem Hippocampus and in Serum from Young, Elder, and Alzheimer's Patients. Int J Mol Sci 2020; 21:ijms21061983. [PMID: 32183254 PMCID: PMC7139760 DOI: 10.3390/ijms21061983] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 11/16/2022] Open
Abstract
One of the characteristics of the cerebral aging process is the presence of chronic inflammation through glial cells, which is particularly significant in neurodegeneration. On the other hand, it has been demonstrated that the aryl hydrocarbon receptor (AHR) participates in the inflammatory response. Currently, evidence in animal models shows that the hallmarks of aging are associated with changes in the AHR levels. However, there is no information concerning the behavior and participation of AHR in the human aging brain or in Alzheimer’s disease (AD). We evaluated the expression of AHR in human hippocampal post-mortem tissue and its association with reactive astrocytes by immunohistochemistry. Besides this, we analyzed through ELISA the AHR levels in blood serum from young and elder participants, and from AD patients. The levels of AHR and glial fibrillar acid protein were higher in elder than in young post-mortem brain samples. AHR was localized mainly in the cytosol of astrocytes and displayed a pattern that resembles extracellular vesicles; this latter feature was more conspicuous in AD subjects. We found higher serum levels of AHR in AD patients than in the other participants. These results suggest that AHR participates in the aging process, and probably in the development of neurodegenerative diseases like AD.
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Affiliation(s)
- Nicte Alaide Ramos-García
- Unidad Periférica de Neurociencias, Instituto Nacional de Neurología y Neurocirugía/Universidad Nacional Autónoma de México. Av. Insurgentes Sur No. 3877 Col. La Fama, Tlalpan, C.P. 14269, Ciudad de México, Mexico;
- Departamento de Biología Celular, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Gustavo A. Madero, C.P. 07360, Ciudad de México, Mexico;
| | - Marisol Orozco-Ibarra
- Laboratorio de Neurobiología Molecular y Celular, Instituto Nacional de Neurología y Neurocirugía. Av. Insurgentes Sur No. 3877 Col. La Fama, Tlalpan, C.P. 14269, Ciudad de México, Mexico;
| | - Enrique Estudillo
- Laboratorio de Reprogramación Celular, Instituto Nacional de Neurología y Neurocirugía/Universidad Nacional Autónoma de México. Av. Insurgentes Sur No. 3877 Col. La Fama, Tlalpan, C.P. 14269, Ciudad de México, Mexico;
| | - Guillermo Elizondo
- Departamento de Biología Celular, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Gustavo A. Madero, C.P. 07360, Ciudad de México, Mexico;
| | - Erick Gómez Apo
- Hospital General de México, “Dr. Eduardo Liceaga”. Dr. Balmis No. 148, Col. Doctores, Cuauhtémoc, C.P. 06720, Ciudad de México, Mexico; (E.G.A.); (L.G.C.M.)
| | - Laura Graciela Chávez Macías
- Hospital General de México, “Dr. Eduardo Liceaga”. Dr. Balmis No. 148, Col. Doctores, Cuauhtémoc, C.P. 06720, Ciudad de México, Mexico; (E.G.A.); (L.G.C.M.)
| | - Ana Luisa Sosa-Ortiz
- Laboratorio de Demencias, Instituto Nacional de Neurología y Neurocirugía, Av. Insurgentes Sur No. 3877 Col. La Fama, Tlalpan, C.P. 14269, Ciudad de México, Mexico;
| | - Mónica Adriana Torres-Ramos
- Unidad Periférica de Neurociencias, Instituto Nacional de Neurología y Neurocirugía/Universidad Nacional Autónoma de México. Av. Insurgentes Sur No. 3877 Col. La Fama, Tlalpan, C.P. 14269, Ciudad de México, Mexico;
- Correspondence: ; Tel.: +52-55-56063822 (ext. 3045)
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Donzelli S, Sacconi A, Turco C, Gallo E, Milano E, Iosue I, Blandino G, Fazi F, Fontemaggi G. Paracrine Signaling from Breast Cancer Cells Causes Activation of ID4 Expression in Tumor-Associated Macrophages. Cells 2020; 9:cells9020418. [PMID: 32054109 PMCID: PMC7072237 DOI: 10.3390/cells9020418] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/03/2020] [Accepted: 02/08/2020] [Indexed: 12/12/2022] Open
Abstract
Background: Tumor-associated macrophages (TAMs) constitute a major portion of the leukocyte infiltrate found in breast cancer (BC). BC cells may reprogram TAMs in a pro-angiogenic and immunosuppressive sense. We previously showed that high expression of the ID4 protein in triple-negative BC cells leads to the induction of a proangiogenic program in TAMs also through the downregulation of miR-107. Here, we investigated the expression and function of the ID4 protein in TAMs. Methods: Human macrophages obtained from peripheral blood-derived monocytes (PBDM) and mouse RAW264.7 cells were used as macrophage experimental systems. ID4-correlated mRNAs of the TCGA and E-GEOD-18295 datasets were analyzed. Results: We observed that BC cells determine a paracrine induction of ID4 expression and activation of the ID4 promoter in neighboring macrophages. Interestingly, ID4 expression is higher in macrophages associated with invasive tumor cells compared to general TAMs, and ID4-correlated mRNAs are involved in various pathways that were previously reported as relevant for TAM functions. Selective depletion of ID4 expression in macrophages enabled validation of the ability of ID4 to control the expression of YAP1 and of its downstream targets CTGF and CYR61. Conclusion: Collectively, our results show that activation of ID4 expression in TAMs is observed as a consequence of BC cell paracrine activity and could participate in macrophage reprogramming in BC.
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Affiliation(s)
- Sara Donzelli
- IRCCS Regina Elena National Cancer Institute, Oncogenomic and Epigenetic Unit, Via E. Chianesi, 53, 00144 Rome, Italy
| | - Andrea Sacconi
- IRCCS Regina Elena National Cancer Institute, Oncogenomic and Epigenetic Unit, Via E. Chianesi, 53, 00144 Rome, Italy
| | - Chiara Turco
- IRCCS Regina Elena National Cancer Institute, Oncogenomic and Epigenetic Unit, Via E. Chianesi, 53, 00144 Rome, Italy
| | - Enzo Gallo
- IRCCS Regina Elena National Cancer Institute, Pathology Department, Via E. Chianesi, 53, 00144 Rome, Italy
| | - Elisa Milano
- IRCCS Regina Elena National Cancer Institute, Oncogenomic and Epigenetic Unit, Via E. Chianesi, 53, 00144 Rome, Italy
| | - Ilaria Iosue
- Department of Anatomical, Histological, Forensic & Orthopaedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Via A. Scarpa, 16, 00161 Rome, Italy
| | - Giovanni Blandino
- IRCCS Regina Elena National Cancer Institute, Oncogenomic and Epigenetic Unit, Via E. Chianesi, 53, 00144 Rome, Italy
- Correspondence: (G.B.); (F.F.); (G.F.); Tel.: +390652662911 (G.B.); +390649766575 (F.F.); +390652662878 (G.F.)
| | - Francesco Fazi
- Department of Anatomical, Histological, Forensic & Orthopaedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Via A. Scarpa, 16, 00161 Rome, Italy
- Laboratory affiliated with Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy
- Correspondence: (G.B.); (F.F.); (G.F.); Tel.: +390652662911 (G.B.); +390649766575 (F.F.); +390652662878 (G.F.)
| | - Giulia Fontemaggi
- IRCCS Regina Elena National Cancer Institute, Oncogenomic and Epigenetic Unit, Via E. Chianesi, 53, 00144 Rome, Italy
- Correspondence: (G.B.); (F.F.); (G.F.); Tel.: +390652662911 (G.B.); +390649766575 (F.F.); +390652662878 (G.F.)
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Gunin AG, Golubtzova NN, Kornilova NK. [Arylhydrocarbon receptor nuclear translocator ( ARNT) in human skin during aging.]. Adv Gerontol 2020; 33:313-318. [PMID: 32593246] [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] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The aim of this work was to examine the content of arylhydrocarbon receptor nuclear translocator (ARNT) in fibroblasts of human dermis from 20 weeks of pregnancy until 85 years old, and defining of a role of ARNT in age-dependent changes in the number of fibroblasts in the dermis. ARNT, proliferating cells nuclear antigen (PCNA) were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for ARNT in the dermis is decreased from 20 weeks of pregnancy to 40 years old. Percent of ARNT positive fibroblasts in dermis is increased sufficiently since 41 year old until 60-85 years old group. A total number and percent of PCNA positive fibroblasts in dermis decreased with progression of age. Most sufficient age-dependent reduction in a total and PCNA positive number of dermal fibroblast was observed from antenatal until 40 years of life. Age-related changes in the content of ARNT in fibroblasts is not associated with an age-related decrease in total number and percent of PCNA positive fibroblasts the dermis.
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Affiliation(s)
- A G Gunin
- I.N.Ulianov Chuvash State University, 15 Moscowski pr., Cheboksary 428015, Russian Federation, e-mail:
| | - N N Golubtzova
- I.N.Ulianov Chuvash State University, 15 Moscowski pr., Cheboksary 428015, Russian Federation, e-mail:
| | - N K Kornilova
- I.N.Ulianov Chuvash State University, 15 Moscowski pr., Cheboksary 428015, Russian Federation, e-mail:
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Abstract
In Neurospora and other fungi, the protein frequency (FRQ) is an integral part and a negative element in the fungal circadian oscillator. In Drosophila and many other higher organisms, the protein period (PER) is an integral part and a negative element of their circadian oscillator. Employing bioinformatic techniques, such as BLAST, CLUSTAL, and MEME (Multiple Em for Motif Elicitation), 11 regions (sequences) of potential similarity were found between the fungal FRQ and the Drosophila PER. Many of these FRQ regions are conserved in many fungal FRQ(s). Many of these PER regions are conserved in many insects. In addition, these regions are also of biological significance since mutations in these regions lead to changes in the circadian clock of Neurospora and Drosophila. Many of these regions of similarity between FRQ and PER are also conserved between the Drosophila PER and the mouse PER (mPER2). This suggests conserved and important regions for all 3 proteins and a common ancestor, possibly in those amoeba, such as Capsaspora, that sits at the base of the phylogenetic tree where fungi and animals diverged. Two additional examples of a possible common ancestor between Neurospora and Drosophila were found. One, the white collar (WC-1) protein of Neurospora and the Drosophila PER, shows significant similarity in its Per/Arnt/Sim (PAS) motifs to the PAS motif of an ARNT-like protein found in the amoeba, Capsaspora. Two, both of the positive elements in each system (i.e., WC-1 in Neurospora and cycle [CYC] in Drosophila), show significant similarity to this Capsaspora ARNT protein. A discussion of these findings centers on the long-time debate about the origins of the many different clock systems (i.e., independent evolution or common ancestor as well as to the question of how new genes are formed).
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Affiliation(s)
- Stuart Brody
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, and Center for Circadian Biology, UCSD, La Jolla, California
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25
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Schurman SH, O'Hanlon TP, McGrath JA, Gruzdev A, Bektas A, Xu H, Garantziotis S, Zeldin DC, Miller FW. Transethnic associations among immune-mediated diseases and single-nucleotide polymorphisms of the aryl hydrocarbon response gene ARNT and the PTPN22 immune regulatory gene. J Autoimmun 2019; 107:102363. [PMID: 31759816 DOI: 10.1016/j.jaut.2019.102363] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Because immune responses are sensitive to environmental changes that drive selection of genetic variants, we hypothesized that polymorphisms of some xenobiotic response and immune response genes may be associated with specific types of immune-mediated diseases (IMD), while others may be associated with IMD as a larger category regardless of specific phenotype or ethnicity. OBJECTIVE To examine transethnic gene-IMD associations for single nucleotide polymorphism (SNP) frequencies of prototypic xenobiotic response genes-aryl hydrocarbon receptor (AHR), AHR nuclear translocator (ARNT), AHR repressor (AHRR) - and a prototypic immune response gene, protein tyrosine phosphatase, non-receptor type 22 (PTPN22), in subjects from the Environmental Polymorphisms Registry (EPR). METHODS Subjects (n = 3731) were genotyped for 14 SNPs associated with functional variants of the AHR, ARNT, AHRR, and PTPN22 genes, and their frequencies were compared among African Americans (n = 1562), Caucasians (n = 1838), and Hispanics (n = 331) with previously reported data. Of those genotyped, 2015 EPR subjects completed a Health and Exposure survey. SNPs were assessed via PLINK for associations with IMD, which included those with autoimmune diseases, allergic disorders, asthma, or idiopathic pulmonary fibrosis. Transethnic meta-analyses were performed using METAL and MANTRA approaches. RESULTS ARNT SNP rs11204735 was significantly associated with autoimmune disease by transethnic meta-analyses using METAL (odds ratio, OR [95% confidence interval] = 1.29 [1.08-1.55]) and MANTRA (ORs ranged from 1.29 to 1.30), whereas ARNT SNP rs1889740 showed a significant association with autoimmune disease by METAL (OR = 1.25 [1.06-1.47]). For Caucasian females, PTPN22 SNP rs2476601 was significantly associated with autoimmune disease by allelic association tests (OR = 1.99, [1.30-3.04]). In Caucasians and Caucasian males, PTPN22 SNP rs3811021 was significantly associated with IMD (OR = 1.39 [1.12-1.72] and 1.50 [1.12-2.02], respectively) and allergic disease (OR = 1.39 [1.12-1.71], and 1.62 [1.19-2.20], respectively). In the transethnic meta-analysis, PTPN22 SNP rs3811021 was significantly implicated in IMD by METAL (OR = 1.31 [1.10-1.56]), and both METAL and MANTRA suggested that rs3811021 was associated with IMD and allergic disease in males across all three ethnic groups (IMD METAL OR = 1.50 [1.15-1.95]; IMD MANTRA ORs ranged from 1.47 to 1.50; allergic disease METAL OR = 1.58 [1.20-2.08]; allergic disease MANTRA ORs ranged from 1.55 to 1.59). CONCLUSIONS Some xenobiotic and immune response gene polymorphisms were shown here, for the first time, to have associations across a broad spectrum of IMD and ethnicities. Our findings also suggest a role for ARNT in the development of autoimmune diseases, implicating environmental factors metabolized by this pathway in pathogenesis. Further studies are needed to confirm these data, assess the implications of these findings, define gene-environment interactions, and explore the mechanisms leading to these increasingly prevalent disorders.
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Affiliation(s)
- Shepherd H Schurman
- Clinical Research Branch, National Institute of Environmental Health Sciences, National Institutes of Health, USA; Research Triangle Park, NC, USA.
| | - Terrance P O'Hanlon
- Clinical Research Branch, National Institute of Environmental Health Sciences, National Institutes of Health, USA; Bethesda, MD, USA.
| | | | - Artiom Gruzdev
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA.
| | - Arsun Bektas
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
| | - Hong Xu
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Bethesda, MD, USA.
| | - Stavros Garantziotis
- Clinical Research Branch, National Institute of Environmental Health Sciences, National Institutes of Health, USA; Research Triangle Park, NC, USA.
| | - Darryl C Zeldin
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA.
| | - Frederick W Miller
- Clinical Research Branch, National Institute of Environmental Health Sciences, National Institutes of Health, USA; Research Triangle Park, NC, USA; Bethesda, MD, USA.
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Greb-Markiewicz B, Kolonko M. Subcellular Localization Signals of bHLH-PAS Proteins: Their Significance, Current State of Knowledge and Future Perspectives. Int J Mol Sci 2019; 20:E4746. [PMID: 31554340 DOI: 10.3390/ijms20194746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/22/2019] [Accepted: 09/23/2019] [Indexed: 12/14/2022] Open
Abstract
The bHLH-PAS (basic helix-loop-helix/ Period-ARNT-Single minded) proteins are a family of transcriptional regulators commonly occurring in living organisms. bHLH-PAS members act as intracellular and extracellular "signals" sensors, initiating response to endo- and exogenous signals, including toxins, redox potential, and light. The activity of these proteins as transcription factors depends on nucleocytoplasmic shuttling: the signal received in the cytoplasm has to be transduced, via translocation, to the nucleus. It leads to the activation of transcription of particular genes and determines the cell response to different stimuli. In this review, we aim to present the current state of knowledge concerning signals that affect shuttling of bHLH-PAS transcription factors. We summarize experimentally verified and published nuclear localization signals/nuclear export signals (NLSs/NESs) in the context of performed in silico predictions. We have used most of the available NLS/NES predictors. Importantly, all our results confirm the existence of a complex system responsible for protein localization regulation that involves many localization signals, which activity has to be precisely controlled. We conclude that the current stage of knowledge in this area is still not complete and for most of bHLH-PAS proteins an experimental verification of the activity of further NLS/NES is needed.
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Ji S, Xin H, Su EJ. Overexpression of the aryl hydrocarbon receptor nuclear translocator partially rescues fetoplacental angiogenesis in severe fetal growth restriction. Clin Sci (Lond) 2019; 133:1353-65. [PMID: 31189688 DOI: 10.1042/CS20190381] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/22/2019] [Accepted: 06/12/2019] [Indexed: 12/30/2022]
Abstract
Pregnancies complicated by severe fetal growth restriction with abnormal umbilical artery Doppler velocimetry (FGRadv) are at substantial risk for adverse perinatal and long-term outcomes. Impaired angiogenesis of the placental vasculature in these pregnancies results in a sparse, poorly branched vascular tree, which structurally contributes to the abnormally elevated fetoplacental vascular resistance that is clinically manifested by absent or reversed umbilical artery Doppler indices. Previous studies have shown that aryl hydrocarbon receptor nuclear translocator (ARNT) is a key mediator of proper placental angiogenesis, and within placental endothelial cells (ECs) from human FGRadv pregnancies, low expression of ARNT leads to decreased vascular endothelial growth factor A (VEGFA) expression and deficient tube formation. Thus, the aim of the present study was to determine the effect of VEGFA administration or ARNT overexpression on angiogenic potential of FGRadv ECs. ECs were isolated and cultured from FGRadv or gestational age-matched control placentas and subjected to either vehicle vs VEGFA treatment or transduction with adenoviral-CMV (ad-CMV) vs adenoviral-ARNT (ad-ARNT) constructs. They were then assessed via wound scratch and tube formation assays. We found that VEGFA administration nominally improved FGRadv EC migration (P<0.01) and tube formation (P<0.05). ARNT overexpression led to significantly enhanced ARNT expression in FGRadv ECs (P<0.01), to a level similar to control ECs. Despite this, FGRadv EC migration (P<0.05) and tube formation (P<0.05) were still only partially rescued. This suggests that although ARNT does play a role in fetoplacental EC migration, other factors in addition to ARNT are likely also important in placental angiogenesis.
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Rahman MS, Thomas P. Molecular cloning and characterization of two ARNT (ARNT-1 and ARNT-2) genes in Atlantic croaker and their expression during coexposure to hypoxia and PCB77. Environ Toxicol 2019; 34:160-171. [PMID: 30334616 DOI: 10.1002/tox.22670] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/28/2018] [Accepted: 09/30/2018] [Indexed: 06/08/2023]
Abstract
Aryl hydrocarbon receptor nuclear translocator (ARNT) is an important transcriptions factor that binds/coactivates drug-metabolizing genes in vertebrates. In this study, we report the cloning and characterization of two ARNT (ARNT-1 and ARNT-2) genes and their mRNA and protein expression in liver tissues of Atlantic croaker after co-exposure to hypoxia and 3,3',4,4'-tetrachlorobiphenyl (PCB77). The full-length croaker ARNT-1 and ARNT-2 genes encode proteins of 537 and 530 amino acids, respectively, and are highly homologous to ARNT-1 and ARNT-2 genes of other vertebrates. ARNT mRNAs are ubiquitously expressed in all tissues. Hypoxia (dissolved oxygen: 1.7 mg/L) exposure (1-4 weeks) did not affect hepatic ARNTs mRNA levels. Dietary PCB77 treatment (2 and 8 μg/g body weight/day for 4 weeks) caused marked increases in ARNTs mRNA and protein levels in normoxic fish. However, coexposure to hypoxia and PCB77 for 4 weeks significantly blunted the increase in ARNTs mRNA and protein levels in response to PCB77 exposure. These results suggest that ARNT activity and functions induced by exposure to PCB aryl hydrocarbon receptor (AhR) agonists could be compromised in croaker inhabiting hypoxic coastal regions.
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Affiliation(s)
- Md Saydur Rahman
- School of Earth, Environmental and Marine Sciences, University of Texas Rio Grande Valley, Brownsville, Texas 78520
- Marine Science Institute, University of Texas at Austin, Port Aransas, Texas 78373
| | - Peter Thomas
- Marine Science Institute, University of Texas at Austin, Port Aransas, Texas 78373
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Abstract
Background NPAS3 encodes a transcription factor which has been associated with multiple human psychiatric and neurodevelopmental disorders. In mice, deletion of Npas3 was found to cause alterations in neurodevelopment, as well as a marked reduction in neurogenesis in the adult mouse hippocampus. This neurogenic deficit, alongside the reduction in cortical interneuron number, likely contributes to the behavioral and cognitive alterations observed in Npas3 knockout mice. Although loss of Npas3 has been found to affect proliferation and apoptosis, the molecular function of NPAS3 is largely uncharacterized outside of predictions based on its high homology to bHLH–PAS transcription factors. Here we set out to characterize NPAS3 as a transcription factor, and to confirm whether NPAS3 acts as predicted for a Class 1 bHLH–PAS family member. Results Through these studies we have experimentally demonstrated that NPAS3 behaves as a true transcription factor, capable of gene regulation through direct association with DNA. NPAS3 and ARNT are confirmed to directly interact in human cells through both bHLH and PAS dimerization domains. The C-terminus of NPAS3 was found to contain a functional transactivation domain. Further, the NPAS3::ARNT heterodimer was shown to directly regulate the expression of VGF and TXNIP through binding of their proximal promoters. Finally, we assessed the effects of three human variants of NPAS3 on gene regulatory function and do not observe significant deficits. Conclusions NPAS3 is a true transcription factor capable of regulating expression of target genes through their promoters by directly cooperating with ARNT. The tested human variants of NPAS3 require further characterization to identify their effects on NPAS3 expression and function in the individuals that carry them. These data enhance our understanding of the molecular function of NPAS3 and the mechanism by which it contributes to normal and abnormal neurodevelopment and neural function. Electronic supplementary material The online version of this article (10.1186/s12867-018-0117-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Leiah M Luoma
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Fred B Berry
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada. .,Department of Surgery, 3002D Li Ka Shing Centre, University of Alberta, Edmonton, AB, T6G 2E1, Canada.
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Wakx A, Nedder M, Tomkiewicz-Raulet C, Dalmasso J, Chissey A, Boland S, Vibert F, Degrelle SA, Fournier T, Coumoul X, Gil S, Ferecatu I. Expression, Localization, and Activity of the Aryl Hydrocarbon Receptor in the Human Placenta. Int J Mol Sci 2018; 19:E3762. [PMID: 30486367 DOI: 10.3390/ijms19123762] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 12/12/2022] Open
Abstract
The human placenta is an organ between the blood of the mother and the fetus, which is essential for fetal development. It also plays a role as a selective barrier against environmental pollutants that may bypass epithelial barriers and reach the placenta, with implications for the outcome of pregnancy. The aryl hydrocarbon receptor (AhR) is one of the most important environmental-sensor transcription factors and mediates the metabolism of a wide variety of xenobiotics. Nevertheless, the identification of dietary and endogenous ligands of AhR suggest that it may also fulfil physiological functions with which pollutants may interfere. Placental AhR expression and activity is largely unknown. We established the cartography of AhR expression at transcript and protein levels, its cellular distribution, and its transcriptional activity toward the expression of its main target genes. We studied the profile of AhR expression and activity during different pregnancy periods, during trophoblasts differentiation in vitro, and in a trophoblast cell line. Using diverse methods, such as cell fractionation and immunofluorescence microscopy, we found a constitutive nuclear localization of AhR in every placental model, in the absence of any voluntarily-added exogenous activator. Our data suggest an intrinsic activation of AhR due to the presence of endogenous placental ligands.
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31
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De Anna JS, Leggieri LR, Arias Darraz L, Cárcamo JG, Venturino A, Luquet CM. Effects of sequential exposure to water accommodated fraction of crude oil and chlorpyrifos on molecular and biochemical biomarkers in rainbow trout. Comp Biochem Physiol C Toxicol Pharmacol 2018; 212:47-55. [PMID: 30012402 DOI: 10.1016/j.cbpc.2018.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/03/2018] [Accepted: 07/05/2018] [Indexed: 01/09/2023]
Abstract
Fish can be simultaneously or sequentially exposed to various kinds of pollutants, resulting in combined effects. Polycyclic aromatic hydrocarbons induce cytochrome P450 monooxygenase 1A (CYP1A) expression, which catalyzes the conversion of the organophosphorus insecticide chlorpyrifos (CPF) into its most active derivative, CPF-oxon. CPF-oxon inhibits CYP1A and other enzymes, including carboxylesterases (CEs) and acetylcholinesterase (AChE). We studied the effects of an in vivo exposure to crude oil water accommodated fraction (WAF) followed by an ex vivo exposure of liver tissue to CPF on the expression of Cyp1a, AhR and ARNT mRNA, CYP1A protein and on the activity of biomarker enzymes in the rainbow trout (Oncorhynchus mykiss). Juvenile rainbow trout were exposed to WAF (62 μg L-1 TPH) for 48 h. Then, liver was dissected out, sliced and exposed to 20 μg L-1 CPF ex vivo for 1 h. Liver tissue was analyzed for mRNA and protein expression and for CEs, AChE, glutathione S-transferase (GST) and CYP1A (EROD) activity. WAF induced Cyp1a mRNA and CYP1A protein expression by 10-fold and 2.5-8.3-fold, respectively, with no effect of CPF. WAF induced AhR expression significantly (4-fold) in control but not in CPF treated liver tissue. ARNT mRNA expression was significantly lowered (5-fold) by WAF. CPF significantly reduced liver EROD activity, independently of WAF pre-treatment. CEs activity was significantly inhibited in an additive manner following in vivo exposure to WAF (42%) and ex vivo exposure to CPF (19%). CPF exposure inhibited AChE activity (37%) and increased GST activity (42%).
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Affiliation(s)
- Julieta S De Anna
- Laboratorio de Ecotoxicología Acuática, INIBIOMA- CONICET- CEAN, Ruta provincial 61, km 3, 8371 Junín de los Andes, Neuquén, Argentina.
| | - Leonardo R Leggieri
- Laboratorio de Ecotoxicología Acuática, INIBIOMA- CONICET- CEAN, Ruta provincial 61, km 3, 8371 Junín de los Andes, Neuquén, Argentina
| | - Luis Arias Darraz
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, Valdivia, Chile
| | - Juan G Cárcamo
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, Valdivia, Chile; Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Chile
| | - Andrés Venturino
- Centro de Investigaciones en Toxicología Ambiental y Agrobiotecnología del Comahue, CITAAC, UNCo-CONICET, Instituto de Biotecnología Agropecuaria del Comahue, Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, Ruta 151, km 12, 8303 Cinco Saltos, Río Negro, Argentina
| | - Carlos M Luquet
- Laboratorio de Ecotoxicología Acuática, INIBIOMA- CONICET- CEAN, Ruta provincial 61, km 3, 8371 Junín de los Andes, Neuquén, Argentina.
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Osterberg JS, Cammen KM, Schultz TF, Clark BW, Di Giulio RT. Genome-wide scan reveals signatures of selection related to pollution adaptation in non-model estuarine Atlantic killifish (Fundulus heteroclitus). Aquat Toxicol 2018; 200:73-82. [PMID: 29727773 PMCID: PMC6957077 DOI: 10.1016/j.aquatox.2018.04.017] [Citation(s) in RCA: 14] [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] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/21/2018] [Accepted: 04/24/2018] [Indexed: 05/09/2023]
Abstract
In many human-altered ecosystems, organisms are increasingly faced with more diverse and complex environmental stressors and pollutant mixtures, to which the adaptations necessary to survive exposure are likely to be numerous and varied. Improving our understanding of the molecular mechanisms that underlie complex polygenic adaptations in natural settings requires significant toxicological, biochemical, physiological, and genomic data rarely available for non-model organisms. Here, we build upon two decades of study of adaptation to anthropogenic pollutants in a population of Atlantic killifish (Fundulus heteroclitus) that inhabits the creosote-contaminated Atlantic Wood Industries Superfund (AW) site on the Elizabeth River, Virginia in the United States. To better understand the genotypes that underlie previously characterized resistance to PCBs and PAHs, we performed Restriction site-Associated DNA sequencing (RADseq) on killifish from AW and two relatively clean reference sites (King's Creek-KC, and Mains Creek-MC). Across the genome, we analyzed over 83,000 loci and 12,000 single nucleotide polymorphisms (SNPs). Shared across both comparisons of killifish from polluted (AW) and relatively unpolluted (KC and MC) sites, we found eight genomic regions with smoothed FST values significantly (p < 0.001) elevated above background. Using the recently published F. heteroclitus reference genome, we identified candidate genes in these significant regions involved in the AHR pathway (e.g. AIP, ARNT1c), as well as genes relating to cardiac structure and function. These genes represent both previously characterized and potentially novel molecular adaptations involved with various aspects of resistance to these environmental toxins.
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Affiliation(s)
- J S Osterberg
- Duke University, Nicholas School of the Environment, Duke Superfund Research Center, Durham, NC, 27708, USA; Duke University, Nicholas School of the Environment, Duke Marine Lab, Beaufort, NC, 28516, USA.
| | - K M Cammen
- Duke University, Nicholas School of the Environment, Duke Marine Lab, Beaufort, NC, 28516, USA
| | - T F Schultz
- Duke University, Nicholas School of the Environment, Duke Marine Lab, Beaufort, NC, 28516, USA
| | - B W Clark
- Duke University, Nicholas School of the Environment, Duke Superfund Research Center, Durham, NC, 27708, USA
| | - R T Di Giulio
- Duke University, Nicholas School of the Environment, Duke Superfund Research Center, Durham, NC, 27708, USA
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Abstract
Animals and humans are exposed each day to a multitude of chemicals in the air, water and food. They have developed a battery of enzymes and transporters that facilitate the biotransformation and elimination of these compounds. Moreover, a majority of these enzymes and transporters are inducible due to the activation of xenobiotic receptors which act as transcription factors for the regulation of their target genes (such as xenobiotic metabolizing enzymes, see below §4 for the AhR). These receptors include several members of the nuclear/steroid receptor family (CAR for Constitutive Androstane Receptor, PXR for Pregnane X Receptor) but also the Aryl hydrocarbon Receptor or AhR, a member of the bHLH-PAS family (basic Helix-Loop-Helix - Period/ARNT/Single minded). In addition to the regulation of xenobiotic metabolism, numerous alternative functions have been characterized for the AhR since its discovery. These alternative functions will be described in this review along with its endogenous functions as revealed by experiments performed on knock-out animals.
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Affiliation(s)
- Lucie Larigot
- INSERM UMR-S 1124, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints-Pères, 75006 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France
| | - Ludmila Juricek
- INSERM UMR-S 1124, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints-Pères, 75006 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France
| | - Julien Dairou
- CNRS 8601, 45 rue des Saints-Pères, 75006 Paris, France
| | - Xavier Coumoul
- INSERM UMR-S 1124, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints-Pères, 75006 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France
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Pappas B, Yang Y, Wang Y, Kim K, Chung HJ, Cheung M, Ngo K, Shinn A, Chan WK. p23 protects the human aryl hydrocarbon receptor from degradation via a heat shock protein 90-independent mechanism. Biochem Pharmacol 2018; 152:34-44. [PMID: 29555469 DOI: 10.1016/j.bcp.2018.03.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/14/2018] [Indexed: 01/29/2023]
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated signaling molecule which is involved in diverse biological functions ranging from cancer metastasis to immune regulation. This receptor forms a cytoplasmic complex with Hsp90, p23, and XAP2. We have previously reported that down-regulation of p23 triggers degradation of the AHR protein, uncovering a potentially dynamic event which controls the cellular AHR levels without ligand treatment. Here we investigate the underlying mechanisms for this p23 effect using wild-type HeLa and the p23 knockdown HeLa cells. Reduction of the Hsp90 and XAP2 contents, however, did not affect the AHR protein levels, implying that this p23 effect on AHR is more than just alteration of the cytoplasmic complex dynamics. Association of p23 with Hsp90 is not important for the modulation of the AHR levels since exogenous expression of p23 mutants with modest Hsp90-binding affinity effectively restored the AHR message and protein levels. The protein folding property of p23 which resides at the terminal 50-amino acid region is not involved for this p23 effect. Results from our interaction study using the affinity purified thioredoxin fusion proteins and GST fusion proteins showed that p23 directly interacts with AHR and the interaction surface lies within AHR amino acid 1-216 and p23 amino acid 1-110. Down-regulation of the p23 protein content promotes the ubiquitination of AHR, indicating that p23 protects AHR from the ubiquitin-meditated protein degradation.
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Tamaoki M, Komatsuzaki R, Komatsu M, Minashi K, Aoyagi K, Nishimura T, Chiwaki F, Hiroki T, Daiko H, Morishita K, Sakai Y, Seno H, Chiba T, Muto M, Yoshida T, Sasaki H. Multiple roles of single-minded 2 in esophageal squamous cell carcinoma and its clinical implications. Cancer Sci 2018; 109:1121-1134. [PMID: 29427302 PMCID: PMC5891185 DOI: 10.1111/cas.13531] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 09/18/2017] [Revised: 01/25/2018] [Accepted: 02/02/2018] [Indexed: 12/16/2022] Open
Abstract
Degree of histological differentiation is an important characteristic of cancers and may be associated with malignant potential. However, in squamous cell carcinomas, a key transcriptional factor regulating tumor differentiation is largely unknown. Chemoradiotherapy (CRT) is a standard treatment for locally advanced esophageal squamous cell carcinoma; however, the survival rate is still below 40%. From microarray data, single‐minded 2 (SIM2) was overexpressed in the epithelial subtype. Here, we investigated the correlation between SIM2 expression and its clinical implication, and in vitro and in vivo functions of SIM2 in tumor differentiation and in CRT sensitivity. Although SIM2 was suppressed in cancerous tissues, SIM2‐high ESCC showed a favorable prognosis in CRT. Transient SIM2 expression followed by 3D culture induced expression of differentiation markers and suppressed epithelial‐mesenchymal transition‐ and basal‐cell markers. Levels of PDPN‐high tumor basal cells and of expression of genes for DNA repair and antioxidant enzymes were reduced in stable transfectants, and they showed high CDDP and H2O2 sensitivities, and their xenografts showed a well‐differentiated histology. Reduction of tumor basal cells was restored by knockdown of aryl hydrocarbon receptor nuclear translocator (ARNT) that interacted with SIM2. Together, SIM2 increases CRT sensitivity through tumor differentiation by cooperation with ARNT.
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Affiliation(s)
- Masashi Tamaoki
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan.,Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rie Komatsuzaki
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan
| | - Masayuki Komatsu
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan
| | - Keiko Minashi
- Department of Clinical Trial Promotion, Chiba Cancer Center, Chiba, Japan
| | - Kazuhiko Aoyagi
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan
| | - Takao Nishimura
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan.,Department of Gastrointestinal Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Fumiko Chiwaki
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan
| | - Tomoko Hiroki
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan
| | - Hiroyuki Daiko
- Esophageal Surgery Division, National Cancer Center, Tokyo, Japan
| | | | - Yoshiharu Sakai
- Department of Gastrointestinal Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tsutomu Chiba
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Manabu Muto
- Department of Therapeutic Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Teruhiko Yoshida
- Fundamental Innovative Oncology Core Center, National Cancer Center, Tokyo, Japan
| | - Hiroki Sasaki
- Department of Translational Oncology, National Cancer Center, Tokyo, Japan
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Gardella KA, Muro I, Fang G, Sarkar K, Mendez O, Wright CW. Aryl hydrocarbon receptor nuclear translocator ( ARNT) isoforms control lymphoid cancer cell proliferation through differentially regulating tumor suppressor p53 activity. Oncotarget 2017; 7:10710-22. [PMID: 26909609 PMCID: PMC4905433 DOI: 10.18632/oncotarget.7539] [Citation(s) in RCA: 15] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/22/2016] [Indexed: 12/25/2022] Open
Abstract
The aryl hydrocarbon receptor nuclear translocator (ARNT) is involved in xenobiotic and hypoxic responses, and we previously showed that ARNT also regulates nuclear factor-κB (NF-κB) signaling by altering the DNA binding activity of the RelB subunit. However, our initial study of ARNT-mediated RelB modulation was based on simultaneous suppression of the two ARNT isoforms, isoform 1 and 3, and precluded the examination of their individual functions. We find here that while normal lymphocytes harbor equal levels of isoform 1 and 3, lymphoid malignancies exhibit a shift to higher levels of ARNT isoform 1. These elevated levels of ARNT isoform 1 are critical to the proliferation of these cancerous cells, as suppression of isoform 1 in a human multiple myeloma (MM) cell line, and an anaplastic large cell lymphoma (ALCL) cell line, triggered S-phase cell cycle arrest, spontaneous apoptosis, and sensitized cells to doxorubicin treatment. Furthermore, co-suppression of RelB or p53 with ARNT isoform 1 prevented cell cycle arrest and blocked doxorubicin induced apoptosis. Together our findings reveal that certain blood cancers rely on ARNT isoform 1 to potentiate proliferation by antagonizing RelB and p53-dependent cell cycle arrest and apoptosis. Significantly, our results identify ARNT isoform 1 as a potential target for anticancer therapies.
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Affiliation(s)
- Kacie A Gardella
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA
| | - Israel Muro
- Division of Pharmacology and Toxicology, and The Center for Molecular and Cellular Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, USA
| | - Gloria Fang
- Division of Pharmacology and Toxicology, and The Center for Molecular and Cellular Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, USA
| | - Krishnakali Sarkar
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA
| | - Omayra Mendez
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA
| | - Casey W Wright
- Division of Pharmacology and Toxicology, and The Center for Molecular and Cellular Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA
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Chen YJ, Huang BY, Yang CN. Molecular modeling on HIF-2α- ARNT dimer destabilization caused by R171A and/or V192D mutations in HIF-2α. J Mol Graph Model 2017; 79:35-45. [PMID: 29132019 DOI: 10.1016/j.jmgm.2017.10.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 08/31/2017] [Revised: 10/12/2017] [Accepted: 10/12/2017] [Indexed: 10/18/2022]
Abstract
Oxygen homeostasis in normal and tumor cells is mediated by hypoxia-inducible factors (HIFs), which are active as heterodimer complexes, such as HIF-2α-aryl hydrocarbon receptor nuclear translocator (ARNT) and HIF-1α-ARNT. A series of mutations on the interfaces between HIF-2α and ARNT and on the domain-domain interface within HIF-2α has been reported to exert varying effects on HIF-2α-ARNT dimerization. In the present study, molecular dynamic simulations were conducted to evaluate HIF-2α mutations, namely R171A, V192D, and R171A/V192D, which are not involved in the interaction with ARNT but impede HIF-2α-ARNT dimerization. Our results indicate that these mutations induct local conformation leading to a shortened (by V192D) or widened (by R171A and R171A/V192D) Y91-E346 separation distance, where E346 and Y91 are located on the HIF-2α and interact with ARNT according to electrostatic and geometrical shape complementarity, respectively.
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Affiliation(s)
- Ya-Jyun Chen
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung, Taiwan
| | - Bo-Yen Huang
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung, Taiwan
| | - Chia-Ning Yang
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung, Taiwan; Scientific Multi-Simulation Center, National University of Kaohsiung, Kaohsiung, Taiwan.
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Jin T, Park KY, Seo SJ. Adiponectin Upregulates Filaggrin Expression via SIRT1-Mediated Signaling in Human Normal Keratinocytes. Ann Dermatol 2017; 29:407-413. [PMID: 28761287 PMCID: PMC5500704 DOI: 10.5021/ad.2017.29.4.407] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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: 07/28/2016] [Revised: 08/17/2016] [Accepted: 08/31/2016] [Indexed: 01/08/2023] Open
Abstract
Background Filaggrin (FLG) is the major component of the epidermal granular layer and binds to and condenses the keratin cytoskeleton. FLG thus contributes to cell compaction and serves as a natural moisturizing factor by promoting unfolding and degradation into hygroscopic amino acids. Loss or downregulation of FLG has been shown to result in a weak stratum corneum, which causes water loss and increases the possibility of skin barrier-related seizure. Adiponectin (Acrp30) contributes to the functional recovery of somatic cells, including human normal epidermal keratinocytes (NHEKs). Objective To investigate the effect of Acrp30 in FLG expression and identifying its signal transduction mechanism. Methods Normal human keratinocytes were treated with Acrp30 and the levels of FLG were examined. Silent mating type information regulation 2 homolog (SIRT)-targeting siRNA and aryl hydrocarbon receptor nuclear translocator (ARNT)-targeting siRNA were used to identify the role of various signal transduction pathway components. Results Acrp30 upregulated SIRT1 and ARNT expression in NHEKs, resulting in increased FLG expression. Treatment with both SIRT1-targeting siRNA and ARNT-targeting siRNA blocked Acrp30 stimulation and silenced FLG expression. Conclusion Adiponectin upregulates FLG expression through a SIRT1-mediated pathway. Our results suggest that Acrp30 is a promising agent for skin barrier permeability improvement.
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Affiliation(s)
- Taewon Jin
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
| | - Kui Young Park
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
| | - Seong Jun Seo
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
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39
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Seok SH, Lee W, Jiang L, Molugu K, Zheng A, Li Y, Park S, Bradfield CA, Xing Y. Structural hierarchy controlling dimerization and target DNA recognition in the AHR transcriptional complex. Proc Natl Acad Sci U S A 2017; 114:5431-6. [PMID: 28396409 DOI: 10.1073/pnas.1617035114] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) belongs to the PAS (PER-ARNT-SIM) family transcription factors and mediates broad responses to numerous environmental pollutants and cellular metabolites, modulating diverse biological processes from adaptive metabolism, acute toxicity, to normal physiology of vascular and immune systems. The AHR forms a transcriptionally active heterodimer with ARNT (AHR nuclear translocator), which recognizes the dioxin response element (DRE) in the promoter of downstream genes. We determined the crystal structure of the mammalian AHR-ARNT heterodimer in complex with the DRE, in which ARNT curls around AHR into a highly intertwined asymmetric architecture, with extensive heterodimerization interfaces and AHR interdomain interactions. Specific recognition of the DRE is determined locally by the DNA-binding residues, which discriminates it from the closely related hypoxia response element (HRE), and is globally affected by the dimerization interfaces and interdomain interactions. Changes at the interdomain interactions caused either AHR constitutive nuclear localization or failure to translocate to nucleus, underlying an allosteric structural pathway for mediating ligand-induced exposure of nuclear localization signal. These observations, together with the global higher flexibility of the AHR PAS-A and its loosely packed structural elements, suggest a dynamic structural hierarchy for complex scenarios of AHR activation induced by its diverse ligands.
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40
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Chen G, Nie S, Han C, Ma K, Xu Y, Zhang Z, Papa SM, Cao X. Antidyskinetic Effects of MEK Inhibitor Are Associated with Multiple Neurochemical Alterations in the Striatum of Hemiparkinsonian Rats. Front Neurosci 2017; 11:112. [PMID: 28337120 PMCID: PMC5343040 DOI: 10.3389/fnins.2017.00112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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: 11/06/2016] [Accepted: 02/21/2017] [Indexed: 12/12/2022] Open
Abstract
L-DOPA-induced dyskinesia (LID) represents one of the major problems of the long-term therapy of patients with Parkinson's disease (PD). Although, the pathophysiologic mechanisms underlying LID are not completely understood, activation of the extracellular signal regulated kinase (ERK) is recognized to play a key role. ERK is phosphorylated by mitogen-activated protein kinase kinase (MEK), and thus MEK inhibitor can prevent ERK activation. Here the effect of the MEK inhibitor PD98059 on LID and the associated molecular changes were examined. Rats with unilateral 6-OHDA lesions of the nigrostriatal pathway received daily L-DOPA treatment for 3 weeks, and abnormal involuntary movements (AIMs) were assessed every other day. PD98059 was injected in the lateral ventricle daily for 12 days starting from day 10 of L-DOPA treatment. Striatal molecular markers of LID were analyzed together with gene regulation using microarray. The administration of PD98059 significantly reduced AIMs. In addition, ERK activation and other associated molecular changes including ΔFosB were reversed in rats treated with the MEK inhibitor. PD98059 induced significant up-regulation of 418 transcripts and down-regulation of 378 transcripts in the striatum. Tyrosine hydroxylase (Th) and aryl hydrocarbon receptor nuclear translocator (Arnt) genes were down-regulated in lesioned animals and up-regulated in L-DOPA-treated animals. Analysis of protein levels showed that PD98059 reduced the striatal TH. These results support the association of p-ERK1/2, ΔFosB, p-H3 to the regulation of TH and ARNT in the mechanisms of LID, and pinpoint other gene regulatory changes, thus providing clues for identifying new targets for LID therapy.
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Affiliation(s)
- Guiqin Chen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Shuke Nie
- Department of Neurology, Renmin Hospital of Wuhan University Wuhan, China
| | - Chao Han
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Kai Ma
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Yan Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University Wuhan, China
| | - Stella M Papa
- Department of Neurology, Yerkes National Primate Research Center, Emory University School of Medicine Atlanta, GA, USA
| | - Xuebing Cao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
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41
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Oka K, Kohno S, Ohta Y, Guillette LJ, Iguchi T, Katsu Y. Molecular cloning and characterization of the aryl hydrocarbon receptors and aryl hydrocarbon receptor nuclear translocators in the American alligator. Gen Comp Endocrinol 2016; 238:13-22. [PMID: 27174749 DOI: 10.1016/j.ygcen.2016.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/27/2016] [Accepted: 05/06/2016] [Indexed: 11/22/2022]
Abstract
Aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, binds to a variety of chemical compounds including various environmental contaminants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin. This receptor regulates expression of target genes through dimerization with the AHR nuclear translocator (ARNT). Since AHR-ARNT signaling pathways differ among species, characterization of AHR and ARNT is important to assess the effects of environmental contamination and for understanding the molecular mechanism underlying the intrinsic function. In this study, we isolated the cDNAs encoding three types of AHR and two types of ARNT from a reptile, the American alligator (Alligator mississippiensis). In vitro reporter gene assays showed that all complexes of alligator AHR-ARNT were able to activate ligand-dependent transcription on a xenobiotic response element. We found that AHR-ARNT complexes had higher sensitivities to a ligand than AHR-ARNT2 complexes. Alligator AHR1B showed the highest sensitivity in transcriptional activation induced by indigo when compared with AHR1A and AHR2. Taken together, our data revealed that all three alligator AHRs and two ARNTs were functional in the AHR signaling pathway with ligand-dependent and isoform-specific transactivations in vitro.
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Affiliation(s)
- Kaori Oka
- Graduate School of Life Science and Department of Biological Sciences, Hokkaido University, Sapporo, Japan
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, and Marine Biomedicine and Environmental Science Center, Medical University of South Carolina, and Hollings Marine Laboratory, Charleston, SC, USA
| | - Yasuhiko Ohta
- Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Koyama, Tottori, Japan
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, and Marine Biomedicine and Environmental Science Center, Medical University of South Carolina, and Hollings Marine Laboratory, Charleston, SC, USA
| | - Taisen Iguchi
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Yoshinao Katsu
- Graduate School of Life Science and Department of Biological Sciences, Hokkaido University, Sapporo, Japan.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Huang CR, Lee CT, Chang KY, Chang WC, Liu YW, Lee JC, Chen BK. Down-regulation of ARNT promotes cancer metastasis by activating the fibronectin/integrin β1/FAK axis. Oncotarget 2016; 6:11530-46. [PMID: 25839165 PMCID: PMC4484474 DOI: 10.18632/oncotarget.3448] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [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: 10/15/2014] [Accepted: 02/25/2015] [Indexed: 01/11/2023] Open
Abstract
The aryl hydrocarbon receptor nuclear translocator (ARNT) is broadly involved in regulating tumorigenesis by inducing genes that are involved in tumor growth and angiogenesis. Tumorigenesis usually involves normoxic conditions. However, the role of ARNT in tumor metastasis during normoxia remains unclear. Here, we demonstrate that ARNT protein levels were decreased in late-stage human colorectal cancer using immunohistochemical analysis. Down-regulation of ARNT protein promoted cancer cell migration and invasion, which was mediated by activation of the fibronectin/integrin β1/FAK signaling axis. In addition, the enhancement of migration and invasion in ANRT knockdown cells was blocked when ARNT was restored in the cells. In xenografts in severe combined immunodeficiency mice, tumor growth was significantly inhibited in the ARNT-knockdown condition. However, the tail-vein injection animal model revealed that the depletion of ARNT-induced metastatic lung colonies was further enhanced when ARNT expression was recovered post-injection. Interestingly, chemotherapeutic drugs inhibited ARNT expression and promoted the invasion of residual tumor cells. These results suggest that ARNT may play a positive role during tumor growth (either in early-stage tumor growth or in organ metastases), but plays a negative role in tumor migration and invasion. Therefore, the efficiency of ARNT-targeted therapy during different cancer stages should be carefully evaluated.
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Affiliation(s)
- Chi-Ruei Huang
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Taiwan, ROC.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taiwan, ROC
| | - Chung-Ta Lee
- Department of Pathology, National Cheng Kung University Hospital, Taiwan, ROC
| | - Kwang-Yu Chang
- National Institute of Cancer Research, National Health Research Institutes, Taiwan, ROC.,Division of Hematology/Oncology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Taiwan, ROC
| | - Wen-Chang Chang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taiwan, ROC
| | - Yao-Wen Liu
- Department of Pathology, Kuo General Hospital, Taiwan, ROC
| | - Jenq-Chang Lee
- Department of Surgery, National Cheng Kung University Hospital, Taiwan, ROC
| | - Ben-Kuen Chen
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Taiwan, ROC.,Department of Pharmacology, College of Medicine, National Cheng Kung University, Taiwan, ROC.,Institute for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taiwan, ROC
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Li W, Liang Y, Yang B, Sun H, Wu W. Downregulation of ARNT2 promotes tumor growth and predicts poor prognosis in human hepatocellular carcinoma. J Gastroenterol Hepatol 2015; 30:1085-93. [PMID: 25611915 DOI: 10.1111/jgh.12905] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [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] [Accepted: 01/02/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND AIM Aryl-hydrocarbon receptor nuclear translocator 2 (ARNT2) is a transcriptional regulator and member of the basic helix-loop-helix/Per-ARNT-SIM (bHLH/PAS) superfamily. Recently, evidence of that ARNT is involved in carcinogenesis and cancer progression has emerged. The aim of current study was to investigate the role of ARNT2, a homolog of ARNT, in tumor growth, invasion, and prognosis of hepatocellular carcinoma (HCC). METHODS Tissue microarray and immunohistochemical staining were used to examine the expression of ARNT2 in 195 HCC tissues. Factors associated with ARNT2 levels were assessed by univariate and multivariate Cox regression analyses. Cell proliferation, migration, and invasion assays were performed by using ARNT2 silencing and overexpressing HCCLM6 cell line. Orthotopic xenograft HCC model was used to elucidate the effects of ARNT2 on HCC progression in vivo. RESULTS High intratumoral of ARNT2 level was well correlated with longer overall survival (OS) and lower tumor to recurrence (TTR) of HCC patients after resection. Multivariate analysis revealed that intratumoral ARNT2 overexpression was an independent prognostic factor for both OS and TTR. Knockdown of ARNT2 in HCCLM6 cells was significantly enhanced while overexpression of ARNT2 significantly inhibited the ability of cell proliferation, invasion, and migration. In animal studies, downregulation of ARNT2 in HCCLM6 cells promoted, whereas upregulation of ARNT2 in HCCLM6 cells reduced HCCLM6 growth in vivo. CONCLUSIONS Our data demonstrate that ARNT2 plays an inhibitory role in HCC progression and suggest that ARNT2 may be a potential prognostic predictor and therapeutic target for HCC.
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Affiliation(s)
- Weiwei Li
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
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Kim BM, Rhee JS, Hwang UK, Seo JS, Shin KH, Lee JS. Dose- and time-dependent expression of aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator ( ARNT) in PCB-, B[a]P-, and TBT-exposed intertidal copepod Tigriopus japonicus. Chemosphere 2015; 120:398-406. [PMID: 25216468 DOI: 10.1016/j.chemosphere.2014.07.099] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/26/2014] [Accepted: 07/28/2014] [Indexed: 05/20/2023]
Abstract
The aryl hydrocarbon receptor (AhR) and aryl hydrocarbon nuclear translocator (ARNT) genes from the copepod Tigriopus japonicus (Tj) were cloned to examine their potential functions in the invertebrate putative AhR-CYP signaling pathway. The amino acid sequences encoded by the Tj-AhR and Tj-ARNT genes showed high similarity to homologs of Daphnia and Drosophila, ranging from 68% and 70% similarity for the AhR genes to 56% for the ARNT genes. To determine whether Tj-AhR and Tj-ARNT are modulated by environmental pollutants, transcriptional expression of Tj-AhR and Tj-ARNT was analyzed in response to exposure to five concentrations of polychlorinated biphenyl (PCB 126) (control, 10, 50, 100, 500 μg L(-1)), benzo[a]pyrene (B[a]P) (control, 5, 10, 50, 100 μg L(-1)), and tributyltin (TBT) (control, 1, 5, 10, 20 μg L(-1)) 24h after exposure. A time-course experiment (0, 3, 6, 12, 24h) was performed to analyze mRNA expression patterns after exposure to PCB, B[a]P, and TBT. T. japonicus exhibited dose-dependent and time-dependent upregulation of Tj-AhR and Tj-ARNT in response to pollutant exposure, and the degree of expression was dependent on the pollutant, suggesting that pollutants such as PCB, B[a]P, and TBT modulate expression of Tj-AhR and Tj-ARNT genes in the putative AhR-CYP signaling pathway.
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Affiliation(s)
- Bo-Mi Kim
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea
| | - Jae-Sung Rhee
- Department of Marine Science, College of Natural Science, Incheon National University, Incheon 406-772, South Korea
| | - Un-Ki Hwang
- Marine Ecological Risk Assessment Center, West Sea Fisheries Research Institute, National Fisheries Research & Development Institute, Incheon 400-420, South Korea
| | - Jung Soo Seo
- Pathology Team, National Fisheries Research & Development Institute, Busan 619-902, South Korea
| | - Kyung-Hoon Shin
- Department of Marine Sciences and Convergent Technology, College of Science and Technology, Hanyang University, Ansan 426-791, South Korea
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea.
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Guo Y, Scheuermann TH, Partch CL, Tomchick DR, Gardner KH. Coiled-coil coactivators play a structural role mediating interactions in hypoxia-inducible factor heterodimerization. J Biol Chem 2015; 290:7707-21. [PMID: 25627682 DOI: 10.1074/jbc.m114.632786] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 11/06/2022] Open
Abstract
The hypoxia-inducible factor complex (HIF-α·aryl hydrocarbon receptor nuclear translocator (ARNT)) requires association with several transcription coactivators for a successful cellular response to hypoxic stress. In addition to the conventional global transcription coactivator CREB-binding protein/p300 (CBP/p300) that binds to the HIF-α transactivation domain, a new group of transcription coactivators called the coiled-coil coactivators (CCCs) interact directly with the second PER-ARNT-SIM (PAS) domain of ARNT (ARNT PAS-B). These less studied transcription coactivators play essential roles in the HIF-dependent hypoxia response, and CCC misregulation is associated with several forms of cancer. To better understand CCC protein recruitment by the heterodimeric HIF transcription factor, we used x-ray crystallography, NMR spectroscopy, and biochemical methods to investigate the structure of the ARNT PAS-B domain in complex with the C-terminal fragment of a coiled-coil coactivator protein, transforming acidic coiled-coil coactivator 3 (TACC3). We found that the HIF-2α PAS-B domain also directly interacts with TACC3, motivating an NMR data-derived model suggesting a means by which TACC3 could form a ternary complex with HIF-2α PAS-B and ARNT PAS-B via β-sheet/coiled-coil interactions. These findings suggest that TACC3 could be recruited as a bridge to cooperatively mediate between the HIF-2α PAS-B·ARNT PAS-B complex, thereby participating more directly in HIF-dependent gene transcription than previously anticipated.
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Affiliation(s)
- Yirui Guo
- From the Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816 and
| | - Thomas H Scheuermann
- From the Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816 and
| | - Carrie L Partch
- From the Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816 and
| | - Diana R Tomchick
- From the Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816 and
| | - Kevin H Gardner
- From the Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816 and the Structural Biology Initiative, CUNY Advanced Science Research Center, and Department of Chemistry, City College of New York, New York, New York 10031
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Han Y, Tao J, Gomer A, Ramirez-Bergeron DL. Loss of endothelial- ARNT in adult mice contributes to dampened circulating proangiogenic cells and delayed wound healing. Vasc Med 2014; 19:429-41. [PMID: 25398385 DOI: 10.1177/1358863x14559588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 12/11/2022]
Abstract
The recruitment and homing of circulating bone marrow-derived cells include endothelial progenitor cells (EPCs) that are critical to neovascularization and tissue regeneration of various vascular pathologies. We report here that conditional inactivation of hypoxia-inducible factor's (HIF) transcriptional activity in the endothelium of adult mice (Arnt(ΔiEC) mice) results in a disturbance of infiltrating cells, a hallmark of neoangiogenesis, during the early phases of wound healing. Cutaneous biopsy punches show distinct migration of CD31(+) cells into wounds of control mice by 36 hours. However, a significant decline in numbers of infiltrating cells with immature vascular markers, as well as decreased transcript levels of genes associated with their expression and recruitment, were identified in wounds of Arnt(ΔiEC) mice. Matrigel plug assays further confirmed neoangiogenic deficiencies alongside a reduction in numbers of proangiogenic progenitor cells from bone marrow and peripheral blood samples of recombinant vascular endothelial growth factor-treated Arnt(ΔiEC) mice. In addition to HIF's autocrine requirements in endothelial cells, our data implicate that extrinsic microenvironmental cues provided by endothelial HIF are pivotal for early migration of proangiogenic cells, including those involved in wound healing.
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Affiliation(s)
- Yu Han
- Case Cardiovascular Research Institute and University Hospitals Harrington Heart & Vascular Institute, Case Western Reserve University School of Medicine, Cleveland, OH, USA University of Rochester, School of Medicine and Dentistry, Rochester, NY, USA
| | - Jiayi Tao
- Case Cardiovascular Research Institute and University Hospitals Harrington Heart & Vascular Institute, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Alla Gomer
- Case Cardiovascular Research Institute and University Hospitals Harrington Heart & Vascular Institute, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Diana L Ramirez-Bergeron
- Case Cardiovascular Research Institute and University Hospitals Harrington Heart & Vascular Institute, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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Basham KJ, Leonard CJ, Kieffer C, Shelton DN, McDowell ME, Bhonde VR, Looper RE, Welm BE. Dioxin exposure blocks lactation through a direct effect on mammary epithelial cells mediated by the aryl hydrocarbon receptor repressor. Toxicol Sci 2014; 143:36-45. [PMID: 25265996 DOI: 10.1093/toxsci/kfu203] [Citation(s) in RCA: 16] [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] [Indexed: 11/15/2022] Open
Abstract
In mammals, lactation is a rich source of nutrients and antibodies for newborn animals. However, millions of mothers each year experience an inability to breastfeed. Exposure to several environmental toxicants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), has been strongly implicated in impaired mammary differentiation and lactation. TCDD and related polyhalogenated aromatic hydrocarbons are widespread industrial pollutants that activate the aryl hydrocarbon receptor (AHR). Despite many epidemiological and animal studies, the molecular mechanism through which AHR signaling blocks lactation remains unclear. We employed in vitro models of mammary differentiation to recapitulate lactogenesis in the presence of toxicants. We demonstrate AHR agonists directly block milk production in isolated mammary epithelial cells. Moreover, we define a novel role for the aryl hydrocarbon receptor repressor (AHRR) in mediating this response. Our mechanistic studies suggest AHRR is sufficient to block transcription of the milk gene β-casein. As TCDD is a prevalent environmental pollutant that affects women worldwide, our results have important public health implications for newborn nutrition.
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Affiliation(s)
- Kaitlin J Basham
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Christopher J Leonard
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Collin Kieffer
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Dawne N Shelton
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Maria E McDowell
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Vasudev R Bhonde
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Ryan E Looper
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
| | - Bryan E Welm
- *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112 *Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah 84112, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 and Department of Surgery, University of Utah, Salt Lake City, Utah 84112
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Vorrink SU, Domann FE. Regulatory crosstalk and interference between the xenobiotic and hypoxia sensing pathways at the AhR- ARNT-HIF1α signaling node. Chem Biol Interact 2014; 218:82-8. [PMID: 24824450 DOI: 10.1016/j.cbi.2014.05.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [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: 01/22/2014] [Revised: 03/29/2014] [Accepted: 05/04/2014] [Indexed: 11/17/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the responses to toxic environmental chemicals such as TCDD or dioxin-like PCBs. To regulate gene expression, the AhR requires its binding partner, the aryl hydrocarbon receptor nuclear translocator (ARNT). ARNT is also required by the hypoxia-inducible factor-1α (HIF-1α), a crucial regulator of responses to conditions of reduced oxygen. The important role of ARNT in both the AhR and HIF-1α signaling pathways establishes a meaningful foundation for a possible crosstalk between these two vitally important signaling pathways. This crosstalk might lead to interference between the two signaling pathways and thus might play a role in the variety of cellular responses after exposure to AhR ligands and reduced oxygen availability. This review focuses on studies that have analyzed the effect of low oxygen environments and hypoxia-mimetic agents on AhR signaling and conversely, the effect of AhR ligands, with a special emphasis on PCBs, on HIF-1α signaling. We highlight studies that assess the role of ARNT, elucidate the mechanism of the crosstalk, and discuss the physiological implications for exposure to AhR-inducing compounds in the context of hypoxia.
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Affiliation(s)
- Sabine U Vorrink
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, USA; Department of Radiation Oncology, The University of Iowa, Iowa City, IA, USA
| | - Frederick E Domann
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, USA; Department of Radiation Oncology, The University of Iowa, Iowa City, IA, USA.
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Cheng DD, Zhao HG, Yang YS, Hu T, Yang QC. GSK3β negatively regulates HIF1α mRNA stability via nucleolin in the MG63 osteosarcoma cell line. Biochem Biophys Res Commun 2014; 443:598-603. [PMID: 24333432 DOI: 10.1016/j.bbrc.2013.12.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 12/03/2013] [Indexed: 11/30/2022]
Abstract
Hypoxia-inducible factor 1α (HIF1α) is a transcription factor involved in the growth, invasion and metastasis of malignant tumors. Glycogen synthase kinase 3 beta (GSK3β) is a protein kinase involved in a variety of signaling pathways, such as the Wnt and NF-κB pathways; this kinase can affect tumor progress through the regulation of transcription factor expression and apoptosis. Recent studies showed that GSK3β was involved in the expression of HIF1α. However, the effect of GSK3β on HIF1α expression in osteosarcoma cells remains unknown. To understand the relationship between GSK3β and HIF1α comprehensively, small RNA interference techniques, Western blot analyses, quantitative real-time PCR analyses and luciferase assays were used in our study. Experimental data revealed that inhibition of GSK3β could increase HIF1α protein levels and expression of its target genes by increasing the stability of the HIF1α mRNA, not by affecting the HIF1α protein stability, and that this process could be mediated by nucleolin.
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Affiliation(s)
- Dong-dong Cheng
- Department of Orthopeadics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Hai-guang Zhao
- Department of Vascular Surgery, Shanghai Jiao Tong University Affiliated Ninth People's Hospital, Shanghai 200011, China
| | - Yun-song Yang
- Huazhong University of Science and Technology, Wuhan 430074, China
| | - Tu Hu
- Department of Orthopeadics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Qing-cheng Yang
- Department of Orthopeadics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
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