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Shirai Y, Suwa T, Kobayashi M, Koyasu S, Harada H. DDX5 enhances HIF-1 activity by promoting the interaction of HIF-1α with HIF-1β and recruiting the resulting heterodimer to its target gene loci. Biol Cell 2024; 116:e2300077. [PMID: 38031929 DOI: 10.1111/boc.202300077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/18/2023] [Accepted: 11/22/2023] [Indexed: 12/01/2023]
Abstract
BACKGROUND INFORMATION Cancer cells acquire malignant characteristics and therapy resistance by employing the hypoxia-inducible factor 1 (HIF-1)-dependent adaptive response to hypoxic microenvironment in solid tumors. Since the underlying molecular mechanisms remain unclear, difficulties are associated with establishing effective therapeutic strategies. RESULTS We herein identified DEAD-box helicase 5 (DDX5) as a novel activator of HIF-1 and found that it enhanced the heterodimer formation of HIF-1α and HIF-1β and facilitated the recruitment of the resulting HIF-1 to its recognition sequence, hypoxia-response element (HRE), leading to the expression of a subset of cancer-related genes under hypoxia. CONCLUSIONS This study reveals that the regulation of HIF-1 recruitment to HRE is an important regulatory step in the control of HIF-1 activity. SIGNIFICANCE The present study provides novel insights for the development of strategies to inhibit the HIF-1-dependent expression of cancer-related genes.
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Affiliation(s)
- Yukari Shirai
- Laboratory of Cancer Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Tatsuya Suwa
- Laboratory of Cancer Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Minoru Kobayashi
- Laboratory of Cancer Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Sho Koyasu
- Laboratory of Cancer Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroshi Harada
- Laboratory of Cancer Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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2
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Tai Y, Zheng L, Liao J, Wang Z, Zhang L. Roles of the HIF-1α pathway in the development and progression of keloids. Heliyon 2023; 9:e18651. [PMID: 37636362 PMCID: PMC10448433 DOI: 10.1016/j.heliyon.2023.e18651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
Keloids, a pathological scar that is induced by the consequence of aberrant wound healing, is still a major global health concern for its unsatisfactory treatment outcomes. HIF-1α, a main regulator of hypoxia, mainly acts through some proteins or signaling pathways and plays important roles in a variety of biological processes. Accumulating evidence has shown that HIF-1α played a crucial role in the process of keloid formation. In this review, we attempted to summarize the current knowledge on the association between HIF-1α expression and the development and progression of keloids. Through a comprehensive analysis, the molecular mechanisms underlying HIF-1α in keloids were shown to be correlated to the proliferation of fibroblasts, angiogenesis, and collagen deposits. The affected proteins and the signaling pathways were multiple. For instance, HIF-1α was reported to promote keloids formation by enhancing angiogenesis, fibroblast proliferation, and collagen deposition through the activation of periostin PI3K/Akt, TGF-β/Smad and TLR4/MyD88/NF-κB pathway. However, the specific effects of HIF-1α on keloids keloid illnesses in clinical practice is are entirely unclear, and further studies in clinical trials are still warranted. Therefore, an in-depth understanding of the biological mechanisms of HIF-1α in keloid formation is significant to develop promising therapeutic targets for the treatment of keloids in clinical practice.
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Affiliation(s)
- Yuncheng Tai
- Department of Burn Surgery, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, 318000, Zhejiang, China
| | - Liying Zheng
- Postgraduate Department, First Affiliated Hospital of Gannan Medical College, Ganzhou, China
| | - Jiao Liao
- Department of Nephrology, Jiaxing Hospital of Traditional Chinese Medicine, Jiaxing, 314000, Zhejiang, China
| | - Zixiong Wang
- Department of Burn and Plastic Surgery, Xinjiang Military General Hospital, Urumqi, 830063, Xinjiang, China
| | - Lai Zhang
- Department of Orthopedics, Taizhou Municipal Hospital, Taizhou, 318000, Zhejiang, China
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3
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Matsuura Y, Miyawaki K. Structures of importin-α bound to the wild-type and an internal deletion mutant of the bipartite nuclear localization signal of HIF-1α. Biochem Biophys Res Commun 2023; 652:1-5. [PMID: 36806083 DOI: 10.1016/j.bbrc.2023.02.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is a heterodimeric transcription factor that plays an important role as a master regulator of oxygen homeostasis. The activity of HIF-1 is regulated in part by dynamic intracellular trafficking of its α subunit (HIF-1α) that can shuttle between the nucleus and cytoplasm. It has been shown that nuclear localization of HIF-1α requires a variant of classic nuclear localization signal (NLS) and that an internal deletion of the amino acid residues (residues 724-751) in the NLS almost abolish the nuclear localization. Here we report the X-ray crystal structure of the nuclear import adaptor importin-α1 bound to the wild-type HIF-1α NLS at 1.8 Å resolution and of importin-α1 bound to the Δ724-751 mutant of the HIF-1α NLS at 1.9 Å resolution. In the wild-type structure, two basic clusters in the HIF-1α NLS made extensive interactions with importin-α1 on two sites (the major site and the minor site). In the mutant structure, the NLS residues still interacted extensively with the major site on importin-α1, but the interactions with the minor site were not observed. The structural data, together with computational analyses of binding free energies, indicate that the loss of the minor-site interactions inhibit nuclear accumulation of HIF-1α.
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Affiliation(s)
- Yoshiyuki Matsuura
- Department of Pharmaceutical Sciences, School of Pharmacy, International University of Health and Welfare, Japan; Division of Biological Science, Graduate School of Science, Nagoya University, Japan.
| | - Kazuya Miyawaki
- Division of Biological Science, Graduate School of Science, Nagoya University, Japan
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4
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Ishii T, Warabi E, Mann GE. Stress Activated MAP Kinases and Cyclin-Dependent Kinase 5 Mediate Nuclear Translocation of Nrf2 via Hsp90α-Pin1-Dynein Motor Transport Machinery. Antioxidants (Basel) 2023; 12:antiox12020274. [PMID: 36829834 PMCID: PMC9952688 DOI: 10.3390/antiox12020274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 01/19/2023] [Accepted: 01/22/2023] [Indexed: 01/28/2023] Open
Abstract
Non-lethal low levels of oxidative stress leads to rapid activation of the transcription factor nuclear factor-E2-related factor 2 (Nrf2), which upregulates the expression of genes important for detoxification, glutathione synthesis, and defense against oxidative damage. Stress-activated MAP kinases p38, ERK, and JNK cooperate in the efficient nuclear accumulation of Nrf2 in a cell-type-dependent manner. Activation of p38 induces membrane trafficking of a glutathione sensor neutral sphingomyelinase 2, which generates ceramide upon depletion of cellular glutathione. We previously proposed that caveolin-1 in lipid rafts provides a signaling hub for the phosphorylation of Nrf2 by ceramide-activated PKCζ and casein kinase 2 to stabilize Nrf2 and mask a nuclear export signal. We further propose a mechanism of facilitated Nrf2 nuclear translocation by ERK and JNK. ERK and JNK phosphorylation of Nrf2 induces the association of prolyl cis/trans isomerase Pin1, which specifically recognizes phosphorylated serine or threonine immediately preceding a proline residue. Pin1-induced structural changes allow importin-α5 to associate with Nrf2. Pin1 is a co-chaperone of Hsp90α and mediates the association of the Nrf2-Pin1-Hsp90α complex with the dynein motor complex, which is involved in transporting the signaling complex to the nucleus along microtubules. In addition to ERK and JNK, cyclin-dependent kinase 5 could phosphorylate Nrf2 and mediate the transport of Nrf2 to the nucleus via the Pin1-Hsp90α system. Some other ERK target proteins, such as pyruvate kinase M2 and hypoxia-inducible transcription factor-1, are also transported to the nucleus via the Pin1-Hsp90α system to modulate gene expression and energy metabolism. Notably, as malignant tumors often express enhanced Pin1-Hsp90α signaling pathways, this provides a potential therapeutic target for tumors.
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Affiliation(s)
- Tetsuro Ishii
- School of Medicine, University of Tsukuba, Tsukuba 305-8577, Japan
- Correspondence:
| | - Eiji Warabi
- School of Medicine, University of Tsukuba, Tsukuba 305-8577, Japan
| | - Giovanni E. Mann
- King’s British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, Faculty of Life Sciences & Medicine, King’s College London, 150 Stamford Street, London SE1 9NH, UK
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5
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Hou J, Yuan Y, Chen P, Lu K, Tang Z, Liu Q, Xu W, Zheng D, Xiong S, Pei H. Pathological Roles of Oxidative Stress in Cardiac Microvascular Injury. Curr Probl Cardiol 2022; 48:101399. [PMID: 36103941 DOI: 10.1016/j.cpcardiol.2022.101399] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 01/06/2023]
Abstract
Cardiac microvascular injury can be a fundamental pathological process that causes high incidence cardiovascular diseases such heart failure, diabetic cardiomyopathy, and hypertension. It is also an independent risk factor for cardiovascular disease. Oxidative stress is a significant pathological process in which the body interferes with the balance of the endogenous antioxidant defense system by producing reactive oxygen species, leading to property changes and dysfunction. It has been demonstrated that oxidative stress is one of the major causes of cardiac microvascular disease. Therefore, additional investigation into the relationship between oxidative stress and cardiac microvascular injury will direct clinical management in the future. In order to give suggestions and support for future in-depth studies, we give a basic overview of the cardiac microvasculature in relation to physiopathology in this review. We also summarize the role of oxidative stress of mitochondrial and non-mitochondrial origin in cardiac microvascular injury and related drug studies.
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Affiliation(s)
- Jun Hou
- Department of Cardiology, Chengdu Third People's Hospital/Affiliated Hospital of Southwest Jiao Tong University, Chengdu 610031, China
| | - Yuan Yuan
- Department of Pharmacy, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Peiwen Chen
- School of Medical and Life Sciences, Chengdu University of TCM, Chengdu 611130, China
| | - Keji Lu
- School of Medical and Life Sciences, Chengdu University of TCM, Chengdu 611130, China
| | - Zhaobing Tang
- Department of Rehabilitation Medicine, The General Hospital of Western Theater Command, Chengdu 610083, China
| | - Qing Liu
- Department of medical engineering, The 950th Hospital of PLA, Yecheng 844900, China
| | - Wu Xu
- Department of Urology, The Fifth Afliated Hospital of Southern Medical University, Guangzhou 510900, China
| | - Dezhi Zheng
- Department of Cardiovascular Surgery, the 960th Hospital of the PLA Joint Logistic Support Force, Jinan 250031, China
| | - Shiqiang Xiong
- Department of Cardiology, Chengdu Third People's Hospital/Affiliated Hospital of Southwest Jiao Tong University, Chengdu 610031, China
| | - Haifeng Pei
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu 610083, China.
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6
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Thévenod F, Schreiber T, Lee WK. Renal hypoxia-HIF-PHD-EPO signaling in transition metal nephrotoxicity: friend or foe? Arch Toxicol 2022; 96:1573-1607. [PMID: 35445830 PMCID: PMC9095554 DOI: 10.1007/s00204-022-03285-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/14/2022] [Indexed: 12/18/2022]
Abstract
The kidney is the main organ that senses changes in systemic oxygen tension, but it is also the key detoxification, transit and excretion site of transition metals (TMs). Pivotal to oxygen sensing are prolyl-hydroxylases (PHDs), which hydroxylate specific residues in hypoxia-inducible factors (HIFs), key transcription factors that orchestrate responses to hypoxia, such as induction of erythropoietin (EPO). The essential TM ion Fe is a key component and regulator of the hypoxia–PHD–HIF–EPO (HPHE) signaling axis, which governs erythropoiesis, angiogenesis, anaerobic metabolism, adaptation, survival and proliferation, and hence cell and body homeostasis. However, inadequate concentrations of essential TMs or entry of non-essential TMs in organisms cause toxicity and disrupt health. Non-essential TMs are toxic because they enter cells and displace essential TMs by ionic and molecular mimicry, e. g. in metalloproteins. Here, we review the molecular mechanisms of HPHE interactions with TMs (Fe, Co, Ni, Cd, Cr, and Pt) as well as their implications in renal physiology, pathophysiology and toxicology. Some TMs, such as Fe and Co, may activate renal HPHE signaling, which may be beneficial under some circumstances, for example, by mitigating renal injuries from other causes, but may also promote pathologies, such as renal cancer development and metastasis. Yet some other TMs appear to disrupt renal HPHE signaling, contributing to the complex picture of TM (nephro-)toxicity. Strikingly, despite a wealth of literature on the topic, current knowledge lacks a deeper molecular understanding of TM interaction with HPHE signaling, in particular in the kidney. This precludes rationale preventive and therapeutic approaches to TM nephrotoxicity, although recently activators of HPHE signaling have become available for therapy.
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Affiliation(s)
- Frank Thévenod
- Institute for Physiology, Pathophysiology and Toxicology, ZBAF, Witten/Herdecke University, Stockumer Strasse 12, 58453, Witten, Germany.
| | - Timm Schreiber
- Institute for Physiology, Pathophysiology and Toxicology, ZBAF, Witten/Herdecke University, Stockumer Strasse 12, 58453, Witten, Germany
| | - Wing-Kee Lee
- Physiology and Pathophysiology of Cells and Membranes, Medical School EWL, Bielefeld University, R.1 B2-13, Morgenbreede 1, 33615 Bielefeld, Germany
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7
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Regulatory Crosstalk between Physiological Low O 2 Concentration and Notch Pathway in Early Erythropoiesis. Biomolecules 2022; 12:biom12040540. [PMID: 35454129 PMCID: PMC9028139 DOI: 10.3390/biom12040540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 12/04/2022] Open
Abstract
Physiological low oxygen (O2) concentration (<5%) favors erythroid development ex vivo. It is known that low O2 concentration, via the stabilization of hypoxia-induced transcription factors (HIFs), intervenes with Notch signaling in the control of cell fate. In addition, Notch activation is implicated in the regulation of erythroid differentiation. We test here if the favorable effects of a physiological O2 concentration (3%) on the amplification of erythroid progenitors implies a cooperation between HIFs and the Notch pathway. To this end, we utilized a model of early erythropoiesis ex vivo generated from cord blood CD34+ cells transduced with shHIF1α and shHIF2α at 3% O2 and 20% O2 in the presence or absence of the Notch pathway inhibitor. We observed that Notch signalization was activated by Notch2R−Jagged1 ligand interaction among progenitors. The inhibition of the Notch pathway provoked a modest reduction in erythroid cell expansion and promoted erythroid differentiation. ShHIF1α and particularly shHIF2α strongly impaired erythroid progenitors’ amplification and differentiation. Additionally, HIF/NOTCH signaling intersects at the level of multipotent progenitor erythroid commitment and amplification of BFU-E. In that, both HIFs contribute to the expression of Notch2R and Notch target gene HES1. Our study shows that HIF, particularly HIF2, has a determining role in the early erythroid development program, which includes Notch signaling.
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8
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Cristea I, Bruland O, Aukrust I, Rødahl E, Bredrup C. Pellino-2 in nonimmune cells: novel interaction partners and intracellular localization. FEBS Lett 2021; 595:2909-2921. [PMID: 34674267 DOI: 10.1002/1873-3468.14212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/04/2021] [Accepted: 10/14/2021] [Indexed: 01/18/2023]
Abstract
Pellino-2 is an E3 ubiquitin ligase that mediates intracellular signaling in innate immune pathways. Most studies of endogenous Pellino-2 have been performed in macrophages, but none in nonimmune cells. Using yeast two-hybrid screening and co-immunoprecipitation, we identified six novel interaction partners of Pellino-2, with various localizations: insulin receptor substrate 1, NIMA-related kinase 9, tumor necrosis factor receptor-associated factor 7, cyclin-F, roundabout homolog 1, and disheveled homolog 2. Pellino-2 showed cytoplasmic localization in a wide range of nonimmune cells under physiological potassium concentrations. Treatment with the potassium ionophore nigericin resulted in nuclear localization of Pellino-2, which was reversed by the potassium channel blocker tetraethylammonium. Live-cell imaging revealed intracellular migration of GFP-tagged Pellino-2. In summary, Pellino-2 interacts with proteins at different cellular locations, taking part in dynamic processes that change its intracellular localization influenced by potassium efflux.
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Affiliation(s)
- Ileana Cristea
- Department of Clinical Medicine, University of Bergen, Norway
| | - Ove Bruland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Ingvild Aukrust
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Norway
| | - Eyvind Rødahl
- Department of Clinical Medicine, University of Bergen, Norway.,Department of Ophthalmology, Haukeland University Hospital, Bergen, Norway
| | - Cecilie Bredrup
- Department of Clinical Medicine, University of Bergen, Norway.,Department of Ophthalmology, Haukeland University Hospital, Bergen, Norway
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9
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Tomc J, Debeljak N. Molecular Pathways Involved in the Development of Congenital Erythrocytosis. Genes (Basel) 2021; 12:1150. [PMID: 34440324 PMCID: PMC8391844 DOI: 10.3390/genes12081150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/24/2021] [Accepted: 07/26/2021] [Indexed: 01/08/2023] Open
Abstract
Patients with idiopathic erythrocytosis are directed to targeted genetic testing including nine genes involved in oxygen sensing pathway in kidneys, erythropoietin signal transduction in pre-erythrocytes and hemoglobin-oxygen affinity regulation in mature erythrocytes. However, in more than 60% of cases the genetic cause remains undiagnosed, suggesting that other genes and mechanisms must be involved in the disease development. This review aims to explore additional molecular mechanisms in recognized erythrocytosis pathways and propose new pathways associated with this rare hematological disorder. For this purpose, a comprehensive review of the literature was performed and different in silico tools were used. We identified genes involved in several mechanisms and molecular pathways, including mRNA transcriptional regulation, post-translational modifications, membrane transport, regulation of signal transduction, glucose metabolism and iron homeostasis, which have the potential to influence the main erythrocytosis-associated pathways. We provide valuable theoretical information for deeper insight into possible mechanisms of disease development. This information can be also helpful to improve the current diagnostic solutions for patients with idiopathic erythrocytosis.
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Affiliation(s)
| | - Nataša Debeljak
- Medical Centre for Molecular Biology, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
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10
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von Fallois M, Kosyna FK, Mandl M, Landesman Y, Dunst J, Depping R. Selinexor decreases HIF-1α via inhibition of CRM1 in human osteosarcoma and hepatoma cells associated with an increased radiosensitivity. J Cancer Res Clin Oncol 2021; 147:2025-2033. [PMID: 33856525 PMCID: PMC8164574 DOI: 10.1007/s00432-021-03626-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/30/2021] [Indexed: 10/29/2022]
Abstract
BACKGROUND The nuclear pore complexes (NPCs) are built of about 30 different nucleoporins and act as key regulators of molecular traffic between the cytoplasm and the nucleus for sizeable proteins (> 40 kDa) which must enter the nucleus. Various nuclear transport receptors are involved in import and export processes of proteins through the nuclear pores. The most prominent nuclear export receptor is chromosome region maintenance 1 (CRM1), also known as exportin 1 (XPO1). One of its cargo proteins is the prolyl hydroxylase 2 (PHD2) which is involved in the initiation of the degradation of hypoxia-inducible factors (HIFs) under normoxia. HIFs are proteins that regulate the cellular adaptation under hypoxic conditions. They are involved in many aspects of cell viability and play an important role in the hypoxic microenvironment of cancer. In cancer, CRM1 is often overexpressed thus being a putative target for the development of new cancer therapies. The newly FDA-approved pharmaceutical Selinexor (KPT-330) selectively inhibits nuclear export via CRM1 and is currently tested in additional Phase-III clinical trials. In this study, we investigated the effect of CRM1 inhibition on the subcellular localization of HIF-1α and radiosensitivity. METHODS Human hepatoma cells Hep3B and human osteosarcoma cells U2OS were treated with Selinexor. Intranuclear concentration of HIF-1α protein was measured using immunoblot analysis. Furthermore, cells were irradiated with 2-8 Gy after treatment with Selinexor compared to untreated controls. RESULTS Selinexor significantly reduced the intranuclear level of HIF-1α protein in human hepatoma cells Hep3B and human osteosarcoma cells U2OS. Moreover, we demonstrated by clonogenic survival assays that Selinexor leads to dose-dependent radiosensitization in Hep3B-hepatoma and U2OS-osteosarcoma cells. CONCLUSION Targeting the HIF pathway by Selinexor might be an attractive tool to overcome hypoxia-induced radioresistance.
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MESH Headings
- Apoptosis
- Bone Neoplasms/drug therapy
- Bone Neoplasms/metabolism
- Bone Neoplasms/pathology
- Bone Neoplasms/radiotherapy
- Carcinoma, Hepatocellular/drug therapy
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Carcinoma, Hepatocellular/radiotherapy
- Cell Proliferation
- Gene Expression Regulation, Neoplastic
- Humans
- Hydrazines/pharmacology
- Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Karyopherins/antagonists & inhibitors
- Karyopherins/genetics
- Karyopherins/metabolism
- Liver Neoplasms/drug therapy
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- Liver Neoplasms/radiotherapy
- Osteosarcoma/drug therapy
- Osteosarcoma/metabolism
- Osteosarcoma/pathology
- Osteosarcoma/radiotherapy
- Radiation Tolerance/drug effects
- Radiation-Sensitizing Agents/pharmacology
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Triazoles/pharmacology
- Tumor Cells, Cultured
- Exportin 1 Protein
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Affiliation(s)
- Moritz von Fallois
- Universität Zu Lübeck, Institut Für Physiologie, Working Group Hypoxia, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Friederike Katharina Kosyna
- Universität Zu Lübeck, Institut Für Physiologie, Working Group Hypoxia, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Markus Mandl
- Universität Zu Lübeck, Institut Für Physiologie, Working Group Hypoxia, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Yosef Landesman
- Karyopharm Therapeutics, 85 Wells Ave, Newton, MA, 02459, USA
| | - Jürgen Dunst
- Universitätsklinikum Schleswig-Holstein, Campus Kiel-Klinik für Strahlentherapie, Arnold-Heller-Straße 3, 24105, Kiel, Germany
| | - Reinhard Depping
- Universität Zu Lübeck, Institut Für Physiologie, Working Group Hypoxia, Ratzeburger Allee 160, 23562, Lübeck, Germany.
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11
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Tomc J, Debeljak N. Molecular Insights into the Oxygen-Sensing Pathway and Erythropoietin Expression Regulation in Erythropoiesis. Int J Mol Sci 2021; 22:ijms22137074. [PMID: 34209205 PMCID: PMC8269393 DOI: 10.3390/ijms22137074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 06/26/2021] [Indexed: 02/07/2023] Open
Abstract
Erythropoiesis is regulated by several factors, including the oxygen-sensing pathway as the main regulator of erythropoietin (EPO) synthesis in the kidney. The release of EPO from the kidney and its binding to the EPO receptor (EPOR) on erythrocyte progenitor cells in the bone marrow results in increased erythropoiesis. Any imbalance in these homeostatic mechanisms can lead to dysregulated erythropoiesis and hematological disorders. For example, mutations in genes encoding key players of oxygen-sensing pathway and regulation of EPO production (HIF-EPO pathway), namely VHL, EGLN, EPAS1 and EPO, are well known causative factors that contribute to the development of erythrocytosis. We aimed to investigate additional molecular mechanisms involved in the HIF-EPO pathway that correlate with erythropoiesis. To this end, we conducted an extensive literature search and used several in silico tools. We identified genes encoding transcription factors and proteins that control transcriptional activation or repression; genes encoding kinases, deacetylases, methyltransferases, conjugating enzymes, protein ligases, and proteases involved in post-translational modifications; and genes encoding nuclear transport receptors that regulate nuclear transport. All these genes may modulate the stability or activity of HIF2α and its partners in the HIF-EPO pathway, thus affecting EPO synthesis. The theoretical information we provide in this work can be a valuable tool for a better understanding of one of the most important regulatory pathways in the process of erythropoiesis. This knowledge is necessary to discover the causative factors that may contribute to the development of hematological diseases and improve current diagnostic and treatment solutions in this regard.
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Affiliation(s)
- Jana Tomc
- Medical Centre for Molecular Biology, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Nataša Debeljak
- Medical Centre for Molecular Biology, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Correspondence: ; Tel.: +386-1-543-7645
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12
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Barreca MM, Zichittella C, Alessandro R, Conigliaro A. Hypoxia-Induced Non-Coding RNAs Controlling Cell Viability in Cancer. Int J Mol Sci 2021; 22:ijms22041857. [PMID: 33673376 PMCID: PMC7918432 DOI: 10.3390/ijms22041857] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/29/2021] [Accepted: 02/10/2021] [Indexed: 01/22/2023] Open
Abstract
Hypoxia, a characteristic of the tumour microenvironment, plays a crucial role in cancer progression and therapeutic response. The hypoxia-inducible factors (HIF-1α, HIF-2α, and HIF-3α), are the master regulators in response to low oxygen partial pressure, modulating hypoxic gene expression and signalling transduction pathways. HIFs’ activation is sufficient to change the cell phenotype at multiple levels, by modulating several biological activities from metabolism to the cell cycle and providing the cell with new characteristics that make it more aggressive. In the past few decades, growing numbers of studies have revealed the importance of non-coding RNAs (ncRNAs) as molecular mediators in the establishment of hypoxic response, playing important roles in regulating hypoxic gene expression at the transcriptional, post-transcriptional, translational, and posttranslational levels. Here, we review recent findings on the different roles of hypoxia-induced ncRNAs in cancer focusing on the data that revealed their involvement in tumour growth.
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Affiliation(s)
- Maria Magdalena Barreca
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Section of Biology and Genetics, University of Palermo, 90133 Palermo, Italy; (M.M.B.); (C.Z.); (R.A.)
| | - Chiara Zichittella
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Section of Biology and Genetics, University of Palermo, 90133 Palermo, Italy; (M.M.B.); (C.Z.); (R.A.)
| | - Riccardo Alessandro
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Section of Biology and Genetics, University of Palermo, 90133 Palermo, Italy; (M.M.B.); (C.Z.); (R.A.)
- Institute for Biomedical Research and Innovation (IRIB), National Research Council (CNR), 90146 Palermo, Italy
| | - Alice Conigliaro
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Section of Biology and Genetics, University of Palermo, 90133 Palermo, Italy; (M.M.B.); (C.Z.); (R.A.)
- Correspondence:
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13
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Xie H, Xu G, Gao Y, Yuan Z. hCINAP serves a critical role in hypoxia‑induced cardiomyocyte apoptosis via modulating lactate production and mitochondrial‑mediated apoptosis signaling. Mol Med Rep 2020; 23:109. [PMID: 33300073 PMCID: PMC7723068 DOI: 10.3892/mmr.2020.11748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 10/30/2020] [Indexed: 12/13/2022] Open
Abstract
Acute myocardial infarction (AMI) is a major cause of heart failure and is associated with insufficient myocardial oxygen supply. However, the molecular mechanisms underlying hypoxia‑induced cardiomyocyte apoptosis are not completely understood. In the present study, the role of human coilin interacting nuclear ATPase protein (hCINAP) in cardiomyocytes was investigated. AC16 cells were divided into the following four groups: i) Small interfering (si)RNA‑control (Ctrl); (ii) siRNA‑hCINAP; (iii) empty vector; and (iv) hCINAP‑Flag. Protein expression was assessed using western blotting. MTT and apoptosis assays were conducted to detect cell viability and apoptosis, respectively. CCK8 assays and apoptosis assays were used to detect cell viability and apoptosis, respectively. hCINAP promoter activity was examined by luciferase reporter assay. hCINAP expression was induced in a hypoxia‑inducible factor‑1α‑dependent manner under hypoxic conditions. Compared with the siRNA‑Ctrl group, hCINAP knockdown inhibited apoptosis, whereas compared with the vector group, hCINAP overexpression increased apoptosis under hypoxic conditions. Mechanistically, compared with the siRNA‑Ctrl group, hCINAP knockdown decreased hypoxia‑induced lactate accumulation via regulating lactate dehydrogenase A activity. Moreover, the results indicated that hCINAP was associated with mitochondrial‑mediated apoptosis via Caspase signaling. Collectively, the present study suggested that hCINAP was an important regulator in hypoxia‑induced apoptosis and may serve as a promising therapeutic target for AMI.
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Affiliation(s)
- Hebing Xie
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing 400037, P.R. China
| | - Gang Xu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing 400037, P.R. China
| | - Yuqi Gao
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing 400037, P.R. China
| | - Zhibin Yuan
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing 400037, P.R. China
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14
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Choi K, Jin M, Zouboulis CC, Lee Y. Increased Lipid Accumulation under Hypoxia in SZ95 Human Sebocytes. Dermatology 2020; 237:131-141. [PMID: 32088721 DOI: 10.1159/000505537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/19/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Excessive sebum is produced by specialized cells called sebocytes and is considered a cause or consequence of acne, sebaceous cysts, hyperplasia, and sebaceous adenoma. OBJECTIVE To report changes in lipid accumulation in human sebocytes under hypoxia, which occurs under conditions of seborrhea. METHODS Sebocytes from the immortalized human gland cell line SZ95 were cultured under conditions of hypoxia for 48 h; lipid formation was confirmed by Nile red and Oil Red O staining. To investigate whether HIF-1α plays a role in lipid accumulation, SZ95 cells transfected or treated with dimethyloxalylglycine (DMOG) were assessed by Nile red. For protein expression of the sterol regulatory element-binding protein-1 (SREBP-1) and perilipin 2 (PLIN2), Western blot analysis was performed. Differentially expressed genes (DEGs) in SZ95 sebocytes under hypoxia were revealed by RNA-Seq analyses, and the statistical significance of the correlation between hypoxic and acne/non-acne skin was evaluated using gene set enrichment analysis. RESULTS Hypoxia induces lipid accumulation in SZ95 sebocytes. In addition, the levels of SREBP-1 and PLIN2 were regulated by HIF-1α in SZ95 sebocytes under hypoxia. RNA-Seq analyses of DEGs in SZ95 sebocytes under hypoxia revealed 256 DEGs, including several lipid droplet-associated genes. DEGs between acne and non-acne skin are significantly enriched in hypoxia gene sets. We also detected 93 differentially expressed inflammatory mediators. CONCLUSIONS To the best of our knowledge, this study is the first to show that a hypoxic microenvironment can increase lipogenesis and provides a link between seborrhea and inflammation.
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Affiliation(s)
- KeunOh Choi
- Department of Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea
| | - Mirim Jin
- Department of Microbiology, College of Medicine, Gachon University, Incheon, Republic of Korea.,Department of Health Science and Technology, GAHIST, Gachon University, Incheon, Republic of Korea
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany
| | - YoungJoo Lee
- Department of Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea,
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15
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Martano M, Altamura G, Power K, Restucci B, Carella F, Borzacchiello G, Maiolino P. Evaluation of Hypoxia-Inducible Factor-1 Alpha (HIF-1α) in Equine Sarcoid: An Immunohistochemical and Biochemical Study. Pathogens 2020; 9:E58. [PMID: 31947661 PMCID: PMC7168668 DOI: 10.3390/pathogens9010058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND equine sarcoids are the most frequent skin tumors in equidae worldwide. It is well known that delta bovine papillomaviruses are their causative agents. We have recently shown the presence in equine sarcoids of abnormal vessel structures, which could cause a hypoxic condition. The aim of this study was to analyze the expression of hypoxia-inducible factor-1 alpha (HIF-1α) in a subset of BPV positive equine sarcoids and explore the relationship with vascular endothelial growth factor (VEGF) expression. RESULTS 80% of equine sarcoids showed strong cytoplasmic staining in >60% of neoplastic fibroblasts, while 20% of samples showed a moderate cytoplasmic staining in 40-60% of neoplastic fibroblasts for HIF-1α. Results of Western blotting (WB) were consistent with immunohistochemistry (IHC). Moreover, a positive correlation between HIF-1α and VEGF expression (r = 0.60, p < 0.01) was observed. CONCLUSION we have shown that HIF-1α was strongly expressed in equine sarcoid. The upregulation of HIF-1α has been described in numerous tumors and can be modulated by many proteins encoded by transforming viruses. Thus, it is also possible that BPV could have a relevant role in HIF-1α pathway regulation, contributing to the development of equine sarcoids by promoting HIF-1α/VEGF mediated tumor angiogenesis.
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Affiliation(s)
- Manuela Martano
- Department of Veterinary Medicine and Animal Productions, Naples University “Federico II”, Via F. Delpino 1, 80137 Naples, Italy; (G.A.); (K.P.); (B.R.); (G.B.); (P.M.)
| | - Gennaro Altamura
- Department of Veterinary Medicine and Animal Productions, Naples University “Federico II”, Via F. Delpino 1, 80137 Naples, Italy; (G.A.); (K.P.); (B.R.); (G.B.); (P.M.)
| | - Karen Power
- Department of Veterinary Medicine and Animal Productions, Naples University “Federico II”, Via F. Delpino 1, 80137 Naples, Italy; (G.A.); (K.P.); (B.R.); (G.B.); (P.M.)
| | - Brunella Restucci
- Department of Veterinary Medicine and Animal Productions, Naples University “Federico II”, Via F. Delpino 1, 80137 Naples, Italy; (G.A.); (K.P.); (B.R.); (G.B.); (P.M.)
| | - Francesca Carella
- Department of Biology, University of Naples Federico II, MSA, 80126 Naples, Italy;
| | - Giuseppe Borzacchiello
- Department of Veterinary Medicine and Animal Productions, Naples University “Federico II”, Via F. Delpino 1, 80137 Naples, Italy; (G.A.); (K.P.); (B.R.); (G.B.); (P.M.)
| | - Paola Maiolino
- Department of Veterinary Medicine and Animal Productions, Naples University “Federico II”, Via F. Delpino 1, 80137 Naples, Italy; (G.A.); (K.P.); (B.R.); (G.B.); (P.M.)
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16
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Subcellular Localization Signals of bHLH-PAS Proteins: Their Significance, Current State of Knowledge and Future Perspectives. Int J Mol Sci 2019; 20:ijms20194746. [PMID: 31554340 PMCID: PMC6801399 DOI: 10.3390/ijms20194746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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17
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Lindsey RC, Cheng S, Mohan S. Vitamin C effects on 5-hydroxymethylcytosine and gene expression in osteoblasts and chondrocytes: Potential involvement of PHD2. PLoS One 2019; 14:e0220653. [PMID: 31390373 PMCID: PMC6685624 DOI: 10.1371/journal.pone.0220653] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/20/2019] [Indexed: 12/02/2022] Open
Abstract
Vitamin C (ascorbic acid, AA) is a well-known regulator of bone and cartilage metabolism. However, the mechanisms of AA’s action in these tissues are only partly understood. In this study, we confirmed that AA contributes to bone and cartilage metabolism by showing decreased articular cartilage and trabecular bone in AA-deficient spontaneous fracture (sfx) mutant mice. In vitro, we found that AA exerts differential effects on chondrocyte and osteoblast differentiation. Since AA is known to increase levels of 5-hydroxymethylcytosine (5-hmC) and induce DNA demethylation via the ten-eleven translocases (TETs), and since prolyl hydroxylase domain-containing protein 2 (PHD2), a known mediator of AA’s effects in these tissues, is part of the same enzyme family as the TETs, we next investigated whether increases in 5-hmC might mediate some of these effects. All TETs and PHDs are expressed in chondrocytes and osteoblasts, and PHD2 is localized in both the cytoplasm and nucleus of the cell, lending plausibility to the hypothesis of altered 5-hmC content in these cells. We found that AA treatment increased levels of 5-hmC in both cell types globally, notably including promoter regions of osteoblast differentiation genes. Furthermore, inhibition of PHD2 decreased 5-hmC levels in chondrocyte differentiation gene promoters, and knockdown of Phd2 in chondrocytes reduced global 5-hmC levels, suggesting for the first time that PHD2 may itself directly mediate increases in 5-hmC in chondrocyte and osteoblast genes. Further investigation of this mechanism could lead to novel therapeutic approaches to treat debilitating diseases such as osteoarthritis and osteoporosis.
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Affiliation(s)
- Richard C. Lindsey
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, United States of America
- Center for Health Disparities and Molecular Medicine, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
- Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
| | - Shaohong Cheng
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, United States of America
| | - Subburaman Mohan
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, United States of America
- Center for Health Disparities and Molecular Medicine, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
- Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
- Department of Medicine, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
- Department of Orthopedics, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
- * E-mail:
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18
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Masterson JC, Biette KA, Hammer JA, Nguyen N, Capocelli KE, Saeedi BJ, Harris RF, Fernando SD, Hosford LB, Kelly CJ, Campbell EL, Ehrentraut SF, Ahmed FN, Nakagawa H, Lee JJ, McNamee EN, Glover LE, Colgan SP, Furuta GT. Epithelial HIF-1α/claudin-1 axis regulates barrier dysfunction in eosinophilic esophagitis. J Clin Invest 2019; 129:3224-3235. [PMID: 31264974 DOI: 10.1172/jci126744] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/16/2019] [Indexed: 12/19/2022] Open
Abstract
Epithelial barrier dysfunction is a significant factor in many allergic diseases, including eosinophilic esophagitis (EoE). Infiltrating leukocytes and tissue adaptations increase metabolic demands and decrease oxygen availability at barrier surfaces. Understanding of how these processes impact barrier is limited, particularly in allergy. Here, we identified a regulatory axis whereby the oxygen-sensing transcription factor HIF-1α orchestrated epithelial barrier integrity, selectively controlling tight junction CLDN1 (claudin-1). Prolonged experimental hypoxia or HIF1A knockdown suppressed HIF-1α-dependent claudin-1 expression and epithelial barrier function, as documented in 3D organotypic epithelial cultures. L2-IL5OXA mice with EoE-relevant allergic inflammation displayed localized eosinophil oxygen metabolism, tissue hypoxia, and impaired claudin-1 barrier via repression of HIF-1α/claudin-1 signaling, which was restored by transgenic expression of esophageal epithelial-targeted stabilized HIF-1α. EoE patient biopsy analysis identified a repressed HIF-1α/claudin-1 axis, which was restored via pharmacologic HIF-1α stabilization ex vivo. Collectively, these studies reveal HIF-1α's critical role in maintaining barrier and highlight the HIF-1α/claudin-1 axis as a potential therapeutic target for EoE.
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Affiliation(s)
- Joanne C Masterson
- Allergy, Inflammation and Remodeling Research Laboratory, Human Health Research Institute, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.,Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Kathryn A Biette
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Juliet A Hammer
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Nathalie Nguyen
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Kelley E Capocelli
- Department of Pathology, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Bejan J Saeedi
- Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Rachel F Harris
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Shahan D Fernando
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Lindsay B Hosford
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Caleb J Kelly
- Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Eric L Campbell
- Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Stefan F Ehrentraut
- Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Faria N Ahmed
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA
| | - Hiroshi Nakagawa
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Eóin N McNamee
- Allergy, Inflammation and Remodeling Research Laboratory, Human Health Research Institute, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Louise E Glover
- Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Sean P Colgan
- Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Glenn T Furuta
- Gastrointestinal Eosinophilic Diseases Program, Department of Pediatrics, University of Colorado School of Medicine; Digestive Health Institute, Children's Hospital Colorado; Aurora, Colorado, USA.,Mucosal Inflammation Program, Department of Medicine, University of Colorado, Aurora, Colorado, USA
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19
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Li A, Zhang Y, Wang Z, Dong H, Fu N, Han X. The roles and signaling pathways of prolyl-4-hydroxylase 2 in the tumor microenvironment. Chem Biol Interact 2019; 303:40-49. [PMID: 30817904 DOI: 10.1016/j.cbi.2019.02.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/16/2019] [Accepted: 02/19/2019] [Indexed: 02/06/2023]
Abstract
Tumor hypoxia is a well-known microenvironmental factor that causes cancer progression and resistance to cancer treatment. Proline hydroxylases (PHDs), a small protein family, belong to an evolutionarily conserved superfamily of dioxygenases, considered the central regulator of the molecular hypoxia response. Prolyl-4-hydroxylase 2 (PHD2), one member of PHDs family, regulates the stability of the hypoxia-inducible factor-1 alpha (HIF-1α) in response to oxygen availability. During hypoxia, the inhibition of PHD2 permits the accumulation of HIF-1α, allowing the cellular adaptation to oxygen limitation, causing activation of numerous genes, which enhances the angiogenesis, metastasis and invasiveness. Accurate regulation of oxygen homeostasis is essential, and which implies PHD2 may have a regulatory role in the pathogenesis of cancer. Although ample evidence exists for a positive correlation between HIFs and tumor formation, metastasis and poor prognosis, the function of the PHD2 in carcinogenesis is less well understood. Despite their original role as the oxygen sensors of the cell and many of the its functions are clearly conveyed through the HIF system, PHD2 is currently known to display HIF-independent and hydroxylase-independent functions in cancer cells and stroma in the control of different cellular pathways. In this review, we summarize the recent advances in the structure, regulation and functions of PHD2 in cancer microenvironment.
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Affiliation(s)
- Anqi Li
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Yu Zhang
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Zuojun Wang
- Department of Pharmacy, Linqu Country People's Hospital, 438 Shanwang Road, Linqu, 262600, China
| | - Hailing Dong
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Nange Fu
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Xiuzhen Han
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China.
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20
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Wang Y, Zhong S, Schofield CJ, Ratcliffe PJ, Lu X. Nuclear entry and export of FIH are mediated by HIF1α and exportin1, respectively. J Cell Sci 2018; 131:jcs219782. [PMID: 30333145 PMCID: PMC6250434 DOI: 10.1242/jcs.219782] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/05/2018] [Indexed: 12/18/2022] Open
Abstract
Hypoxia plays a crucial role at cellular and physiological levels in all animals. The responses to chronic hypoxia are, at least substantially, orchestrated by activation of the hypoxia inducible transcription factors (HIFs), whose stability and subsequent transcriptional activation are regulated by HIF hydroxylases. Factor inhibiting HIF (FIH), initially isolated as a HIFα interacting protein following a yeast two-hybrid screen, is an asparaginyl hydroxylase that negatively regulates transcriptional activation by HIF. This study aimed to define the mechanisms that govern transitions of FIH between the nucleus and cytoplasm. We report that FIH accumulates in the nucleus within a short time window during hypoxia treatment. We provide evidence, based on the application of genetic interventions and small molecule inhibition of the HIF hydroxylases, that the nuclear localization of FIH is governed by two opposing processes: nuclear entry by 'coupling' with HIF1α for importin β1-mediated nuclear import and active export via a Leptomycin B-sensitive exportin1-dependent pathway.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Yihua Wang
- Ludwig Institute for Cancer Research Ltd., Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
- Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Shan Zhong
- Ludwig Institute for Cancer Research Ltd., Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Christopher J Schofield
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Peter J Ratcliffe
- Ludwig Institute for Cancer Research Ltd., Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
- Target Discovery Institute, NDM Research Building, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7FZ, United Kingdom
| | - Xin Lu
- Ludwig Institute for Cancer Research Ltd., Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
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21
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Koyasu S, Kobayashi M, Goto Y, Hiraoka M, Harada H. Regulatory mechanisms of hypoxia-inducible factor 1 activity: Two decades of knowledge. Cancer Sci 2018; 109:560-571. [PMID: 29285833 PMCID: PMC5834787 DOI: 10.1111/cas.13483] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/09/2017] [Accepted: 12/24/2017] [Indexed: 12/12/2022] Open
Abstract
Hypoxia‐inducible factor 1 (HIF‐1) is a transcriptional activator of various genes related to cellular adaptive responses to hypoxia. Dysfunctions in the regulatory systems of HIF‐1 activity have been implicated in the pathogenesis of various diseases including malignant tumors and, thus, elucidating the molecular mechanisms underlying the activation of HIF‐1 is eagerly desired for the development of novel anti‐cancer strategies. The importance of oxygen‐dependent and ubiquitin‐mediated proteolysis of the regulatory subunit of HIF‐1 (HIF‐1α) was first reported in 1997. Since then, accumulating evidence has shown that HIF‐1α may become stable and active even under normoxic conditions; for example, when disease‐associated genetic and functional alterations in some genes trigger the aberrant activation of HIF‐1 regardless of oxygen conditions. We herein review the last two decades of knowledge, since 1997, on the regulatory mechanisms of HIF‐1 activity from conventional oxygen‐ and proteolysis‐dependent mechanisms to up‐to‐the‐minute information on cancer‐associated genetic and functional alteration‐mediated mechanisms.
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Affiliation(s)
- Sho Koyasu
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Kyoto, Japan.,Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Minoru Kobayashi
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Kyoto, Japan
| | - Yoko Goto
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Harada
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Kyoto, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST), Saitama, Japan
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Depping R, Oster H. Interplay between environmentally modulated feedback loops - hypoxia and circadian rhythms - two sides of the same coin? FEBS J 2017; 284:3801-3803. [PMID: 29154494 DOI: 10.1111/febs.14306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sensing of environmental parameters is critically important for cells of metazoan organisms. Members of the superfamily of bHLH-PAS transcription factors, involved in oxygen sensing and circadian rhythm generation, are important players in such molecular pathways. The interplay between both networks includes a so far unknown factor, connecting PER2 (circadian clocks) to hypoxia sensing (HIF-1 α) to result in a more adapted state of homeostasis at the right time.
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Affiliation(s)
| | - Henrik Oster
- Institute for Neurobiology, University of Lübeck, Germany
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23
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Park CV, Ivanova IG, Kenneth NS. XIAP upregulates expression of HIF target genes by targeting HIF1α for Lys63-linked polyubiquitination. Nucleic Acids Res 2017; 45:9336-9347. [PMID: 28666324 PMCID: PMC5766203 DOI: 10.1093/nar/gkx549] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 06/26/2017] [Indexed: 01/25/2023] Open
Abstract
The cellular response to hypoxia is characterised by a switch in the transcriptional program, mediated predominantly by the hypoxia inducible factor family of transcription factors (HIF). Regulation of HIF1 is primarily controlled by post-translational modification of the HIF1α subunit, which can alter its stability and/or activity. This study identifies an unanticipated role for the X-linked inhibitor of apoptosis (XIAP) protein as a regulator of Lys63-linked polyubiquitination of HIF1α. Lys63-linked ubiquitination of HIF1α by XIAP is dependent on the activity of E2 ubiquitin conjugating enzyme Ubc13. We find that XIAP and Ubc13 dependent Lys63-linked polyubiquitination promotes HIF1α nuclear retention leading to an increase in the expression of HIF1 responsive genes. Inhibition of the Lys63-linked polyubiquitination pathway leads to reduced levels of nuclear HIF1α, promoter occupancy, HIF-dependent gene expression and cell viability. Our data reveals an additional and significant level of control of the HIF1 by XIAP, with important implications in understanding the role of HIF1 and XIAP in human disease.
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Affiliation(s)
- Catherine V Park
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Iglika G Ivanova
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Niall S Kenneth
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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24
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Kobayashi M, Morinibu A, Koyasu S, Goto Y, Hiraoka M, Harada H. A circadian clock gene, PER2, activates HIF-1 as an effector molecule for recruitment of HIF-1α to promoter regions of its downstream genes. FEBS J 2017; 284:3804-3816. [PMID: 28963769 DOI: 10.1111/febs.14280] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 08/29/2017] [Accepted: 09/25/2017] [Indexed: 12/23/2022]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is a transcription factor functioning in cellular adaptive responses to hypoxia. Recent studies have suggested that HIF-1 activity is upregulated by one of the important circadian clock genes, period circadian clock 2 (PER2); however, its underlying mechanism remains unclear. Here, we show that PER2 functions as an effector protein for the recruitment of HIF-1α to its cognate enhancer sequence, the hypoxia-response element (HRE). We found that the forced expression of PER2 enhanced HIF-1 activity without influencing expression levels of the regulatory subunit of HIF-1, HIF-1α, at either mRNA or protein levels. A series of coimmunoprecipitation-based experiments revealed that PER2 interacted with HIF-1α and facilitated the recruitment of HIF-1α to HRE derived from vascular endothelial growth factor (VEGF) promoter. The PER2-mediated activation of HIF-1 was observed only when the asparagine residue at position 803 of HIF-1α (HIF-1α N803) was kept unhydroxylated by hypoxic stimulation, by introducing an N803A point mutation, or by an inhibitor of N803-dioxygenase, deferoxamine. However, the extent of PER-2-HIF-1α interaction was equivalent regardless of the N803 hydroxylation status. Taken together, these results suggest that, with the help of an unknown sensor molecule for the N803 hydroxylation status, PER2 functions as an effector molecule for the recruitment of HIF-1 to promoter regions of its downstream genes. Our findings reveal a novel regulatory step in the activation of HIF-1, which can be targeted to develop therapeutic strategies against HIF-1-related diseases, such as cancers.
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Affiliation(s)
- Minoru Kobayashi
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Japan
| | - Akiyo Morinibu
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Japan
| | - Sho Koyasu
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Japan.,Research Center for Advanced Science and Technology, The University of Tokyo, Japan
| | - Yoko Goto
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan
| | - Masahiro Hiraoka
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan.,Japan Red Cross Society Wakayama Medical Center, Japan
| | - Hiroshi Harada
- Laboratory of Cancer Cell Biology, Department of Genome Dynamics, Radiation Biology Center, Kyoto University, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Japan
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25
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Mandl M, Depping R. ARNT is a potential direct HIF-1 target gene in human Hep3B hepatocellular carcinoma cells. Cancer Cell Int 2017; 17:77. [PMID: 28855849 PMCID: PMC5571568 DOI: 10.1186/s12935-017-0446-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 08/13/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The transcription factor aryl hydrocarbon receptor nuclear translocator (ARNT) participates in the hypoxia-inducible factor (HIF) pathway which senses a decline in cellular oxygen tension. In hypoxia, HIF-1α and ARNT form the transcriptional active complex HIF-1 followed by the expression of target genes. ARNT is considered as constitutively expressed and unaffected by hypoxia. However, certain tumour cell lines derived from different entities are capable to elevate ARNT expression under hypoxic conditions which implies a survival benefit. It was demonstrated that high ARNT protein levels mediate radioresistance in tumour cells. Furthermore, a HIF-1α-driven feed-forward loop leading to augmented HIF signalling was discovered in Hep3B cells. Herein HIF-1α elevates the mRNA and protein expression of its binding partner ARNT in hypoxia. However, the detailed mechanism remained unclear. The objective of this study was to test whether HIF-1α might directly regulate ARNT expression by recruitment to the ARNT promoter. METHODS Chromatin immunoprecipitation (ChIP), CRISPR/Cas9 genome editing, Western blotting, quantitative RT-PCR and reporter gene assays were applied. The unpaired t test was used for statistical analysis. RESULTS ChIP assays revealed the binding of both HIF-1α and ARNT to the ARNT promoter in hypoxia. The relevance of this particular region for hypoxic ARNT induction was confirmed by CRISPR/Cas9 genome editing. ARNT normoxic basal expression and hypoxic inducibility was reduced in genome-edited Hep3B cells. This phenotype was accompanied with impaired HIF signalling and was rescued by ARNT overexpression. CONCLUSIONS The results indicate ARNT to be a putative HIF-1 target gene and a limiting factor in this model.
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Affiliation(s)
- Markus Mandl
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.,Division of Cell Metabolism and Differentiation Research, Institute for Biomedical Aging Research, University of Innsbruck, Rennweg 10, 6020 Innsbruck, Austria
| | - Reinhard Depping
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
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26
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Liu YJ, Tsai PY, Chern Y. Energy Homeostasis and Abnormal RNA Metabolism in Amyotrophic Lateral Sclerosis. Front Cell Neurosci 2017; 11:126. [PMID: 28522961 PMCID: PMC5415567 DOI: 10.3389/fncel.2017.00126] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/18/2017] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease that is clinically characterized by progressive muscle weakness and impaired voluntary movement due to the loss of motor neurons in the brain, brain stem and spinal cord. To date, no effective treatment is available. Ample evidence suggests that impaired RNA homeostasis and abnormal energy status are two major pathogenesis pathways in ALS. In the present review article, we focus on recent studies that report molecular insights of both pathways, and discuss the possibility that energy dysfunction might negatively regulate RNA homeostasis via the impairment of cytoplasmic-nuclear shuttling in motor neurons and subsequently contribute to the development of ALS.
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Affiliation(s)
- Yu-Ju Liu
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
| | - Po-Yi Tsai
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
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27
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Morshed A, Dutta P. Hypoxic behavior in cells under controlled microfluidic environment. Biochim Biophys Acta Gen Subj 2017; 1861:759-771. [PMID: 28111315 DOI: 10.1016/j.bbagen.2017.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 01/15/2017] [Accepted: 01/18/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND Depleted oxygen levels, known as hypoxia, causes considerable changes in the cellular metabolism. Hypoxia-inducible factors (HIF) act as the major protagonist in orchestrating manifold hypoxic responses by escaping cellular degradation mechanisms. These complex and dynamic intracellular responses are significantly dependent on the extracellular environment. In this study, we present a detailed model of a hypoxic cellular microenvironment in a microfluidic setting involving HIF hydroxylation. METHODS We have modeled the induction of hypoxia in a microfluidic chip by an unsteady permeation of oxygen from the microchannel through a porous polydimethylsiloxane channel wall. Extracellular and intracellular interactions were modeled with two different mathematical descriptions. Intracellular space is directly coupled to the extracellular environment through uptake and consumption of oxygen and ascorbate similar to cells in vivo. RESULTS Our results indicate a sharp switch in HIF hydroxylation behavior with changing prolyl hydroxylase levels from 0.1 to 4.0μM. Furthermore, we studied the effects of extracellular ascorbate concentration, using a new model, to predict its accumulation inside the cell over a relevant physiological range. In different hypoxic conditions, the cellular environment showed a significant dependence on oxygen levels in resulting intracellular response. CONCLUSIONS Change in hydroxylation behavior and nutrient supplementation can have significant potential in designing novel therapeutic interventions in cancer and ischemia/reperfusion injuries. GENERAL SIGNIFICANCE The hybrid mathematical model can effectively predict intracellular behavior due to external influences providing valuable directions in designing future experiments.
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Affiliation(s)
- Adnan Morshed
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, United States
| | - Prashanta Dutta
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, United States.
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28
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A HIF-1α-driven feed-forward loop augments HIF signalling in Hep3B cells by upregulation of ARNT. Cell Death Dis 2016; 7:e2284. [PMID: 27362802 PMCID: PMC5108338 DOI: 10.1038/cddis.2016.187] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 02/07/2023]
Abstract
Oxygen-deprived (hypoxic) areas are commonly found within neoplasms caused by excessive cell proliferation. The transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) is part of the hypoxia-inducible factor (HIF) pathway, which mediates adaptive responses to ensure cellular survival under hypoxic conditions. HIF signalling leads to metabolic alterations, invasion/metastasis and the induction of angiogenesis in addition to radio-chemoresistance of tumour cells. Activation of the HIF pathway is based on the abundance of HIF-α subunits, which are regulated in an oxygen-dependent manner and form transcriptional active complexes with ARNT or ARNT2 (also referred as HIF-1β and HIF-2β, respectively). ARNT is considered to be unaffected by hypoxia but certain cell lines, including Hep3B cells, are capable to elevate this transcription factor in response to oxygen deprivation, which implies an advantage. Therefore, the aim of this study was to elucidate the mechanism of hypoxia-dependent ARNT upregulation and to determine implications on HIF signalling. Gene silencing and overexpression techniques were used to alter the expression pattern of HIF transcription factors under normoxic and hypoxic conditions. qRT-PCR and western blotting were performed to measure gene and protein expression, respectively. HIF activity was determined by reporter gene assays. The results revealed a HIF-1α-dependent mechanism leading to ARNT upregulation in hypoxia. Forced expression of ARNT increased reporter activity under normoxic and hypoxic conditions. In conclusion, these findings indicate a novel feed-forward loop and suggest that ARNT might be a limiting factor. Augmented HIF signalling in terms of elevated target gene expression might be advantageous for tumour cells.
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29
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Connectivity mapping (ssCMap) to predict A20-inducing drugs and their antiinflammatory action in cystic fibrosis. Proc Natl Acad Sci U S A 2016; 113:E3725-34. [PMID: 27286825 DOI: 10.1073/pnas.1520289113] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cystic fibrosis (CF) lung disease is characterized by chronic and exaggerated inflammation in the airways. Despite recent developments to therapeutically overcome the underlying functional defect in the cystic fibrosis transmembrane conductance regulator, there is still an unmet need to also normalize the inflammatory response. The prolonged and heightened inflammatory response in CF is, in part, mediated by a lack of intrinsic down-regulation of the proinflammatory NF-κB pathway. We have previously identified reduced expression of the NF-κB down-regulator A20 in CF as a key target to normalize the inflammatory response. Here, we have used publicly available gene array expression data together with a statistically significant connections' map (sscMap) to successfully predict drugs already licensed for the use in humans to induce A20 mRNA and protein expression and thereby reduce inflammation. The effect of the predicted drugs on A20 and NF-κB(p65) expression (mRNA) as well as proinflammatory cytokine release (IL-8) in the presence and absence of bacterial LPS was shown in bronchial epithelial cells lines (16HBE14o-, CFBE41o-) and in primary nasal epithelial cells from patients with CF (Phe508del homozygous) and non-CF controls. Additionally, the specificity of the drug action on A20 was confirmed using cell lines with tnfαip3 (A20) knockdown (siRNA). We also show that the A20-inducing effect of ikarugamycin and quercetin is lower in CF-derived airway epithelial cells than in non-CF cells.
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30
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Huang X, He Z, Jiang X, Hou M, Tang Z, Zhen X, Liang Y, Ma J. Folic Acid Represses Hypoxia-Induced Inflammation in THP-1 Cells through Inhibition of the PI3K/Akt/HIF-1α Pathway. PLoS One 2016; 11:e0151553. [PMID: 26974319 PMCID: PMC4790958 DOI: 10.1371/journal.pone.0151553] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 03/01/2016] [Indexed: 11/21/2022] Open
Abstract
Though hypoxia has been implicated as a cause of inflammation, the underlying mechanism is not well understood. Folic acid has been shown to provide protection against oxidative stress and inflammation in patients with cardiovascular disease and various models approximating insult to tissue via inflammation. It has been reported that hypoxia-induced inflammation is associated with oxidative stress, upregulation of hypoxia-inducible factor 1-alpha (HIF-1α), and production of pro-inflammatory molecules. Whether folic acid protects human monocytic cells (THP-1 cells) against hypoxia-induced damage, however, remains unknown. We used THP-1 cells to establish a hypoxia-induced cellular injury model. Pretreating THP-1 cells with folic acid attenuated hypoxia-induced inflammatory responses, including a decrease in protein and mRNA levels of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α), coupled with increased levels of IL-10. Folic acid also reduced hypoxia-induced Akt phosphorylation and decreased nuclear accumulation of HIF-1α protein. Both LY294002 (a selective inhibitor of phosphatidyl inositol-3 kinase, PI3K) and KC7F2 (a HIF-1α inhibitor) reduced levels of hypoxia-induced inflammatory cytokines. We also found that insulin (an Akt activator) and dimethyloxallyl glycine (DMOG, a HIF-1α activator) induced over-expression of inflammatory cytokines, which could be blocked by folic acid. Taken together, these findings demonstrate how folic acid attenuates the hypoxia-induced inflammatory responses of THP-1 cells through inhibition of the PI3K/Akt/HIF-1α pathway.
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Affiliation(s)
- Xiaoyan Huang
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Zhiying He
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Xinwei Jiang
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Mengjun Hou
- Experimental and Teaching Center for public health, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Zhihong Tang
- Experimental and Teaching Center for public health, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Xiaozhou Zhen
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Yuming Liang
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Jing Ma
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, P. R. China
- * E-mail:
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31
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Kietzmann T, Mennerich D, Dimova EY. Hypoxia-Inducible Factors (HIFs) and Phosphorylation: Impact on Stability, Localization, and Transactivity. Front Cell Dev Biol 2016; 4:11. [PMID: 26942179 PMCID: PMC4763087 DOI: 10.3389/fcell.2016.00011] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/08/2016] [Indexed: 12/18/2022] Open
Abstract
The hypoxia-inducible factor α-subunits (HIFα) are key transcription factors in the mammalian response to oxygen deficiency. The HIFα regulation in response to hypoxia occurs primarily on the level of protein stability due to posttranslational hydroxylation and proteasomal degradation. However, HIF α-subunits also respond to various growth factors, hormones, or cytokines under normoxia indicating involvement of different kinase pathways in their regulation. Because these proteins participate in angiogenesis, glycolysis, programmed cell death, cancer, and ischemia, HIFα regulating kinases are attractive therapeutic targets. Although numerous kinases were reported to regulate HIFα indirectly, direct phosphorylation of HIFα affects HIFα stability, nuclear localization, and transactivity. Herein, we review the role of phosphorylation-dependent HIFα regulation with emphasis on protein stability, subcellular localization, and transactivation.
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Affiliation(s)
- Thomas Kietzmann
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of OuluFinland
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32
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Mandl M, Lieberum MK, Dunst J, Depping R. The expression level of the transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) determines cellular survival after radiation treatment. Radiat Oncol 2015; 10:229. [PMID: 26572229 PMCID: PMC4647475 DOI: 10.1186/s13014-015-0539-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/10/2015] [Indexed: 12/14/2022] Open
Abstract
Background Tumour hypoxia promotes radioresistance and is associated with poor prognosis. The transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT), also designated as Hypoxia-inducible factor (HIF)-1β, is part of the HIF pathway which mediates cellular adaptations to oxygen deprivation and facilitates tumour progression. The subunits HIF-1α and ARNT are key players within this pathway. HIF-1α is regulated in an oxygen-dependent manner whereas ARNT is considered to be constitutively expressed. However, there is mounting evidence that certain tumour cells are capable to elevate ARNT in hypoxia which suggests a survival benefit. Therefore the objective of this study was to elucidate effects of an altered ARNT expression level on the cellular response to radiation. Methods Different human cell lines (Hep3B, MCF-7, 786-Owt, 786-Ovhl, RCC4wt and RCC4vhl) originating from various tumour entities (Hepatocellular carcinoma, breast cancer and renal cell carcinoma respectively) were X-irradiated using a conventional linear accelerator. Knockdown of ARNT expression was achieved by transient siRNA transfection. Complementary experiments were performed by forced ARNT overexpression using appropriate plasmids. Presence/absence of ARNT protein was confirmed by Western blot analysis. Clonogenic survival assays were performed in order to determine cellular survival post irradiation. Statistical comparison of two groups was achieved by the unpaired t-test. Results The results of this study indicate that ARNT depletion renders tumour cells susceptible to radiation whereas overexpression of this transcription factor confers radioresistance. Conclusions These findings provide evidence to consider ARNT as a drug target and as a predictive marker in clinical applications concerning the response to radiation. Electronic supplementary material The online version of this article (doi:10.1186/s13014-015-0539-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Markus Mandl
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562, Luebeck, Germany.
| | - Maria- Katharina Lieberum
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562, Luebeck, Germany. .,Klinik für Strahlentherapie, Universitaetsklinikum Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, 23538, Luebeck, Germany.
| | - Juergen Dunst
- Klinik für Strahlentherapie, Universitaetsklinikum Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, 23538, Luebeck, Germany.
| | - Reinhard Depping
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562, Luebeck, Germany.
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