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Potts KS, Farley A, Dawson CA, Rimes J, Biben C, de Graaf C, Potts MA, Stonehouse OJ, Carmagnac A, Gangatirkar P, Josefsson EC, Anttila C, Amann-Zalcenstein D, Naik S, Alexander WS, Hilton DJ, Hawkins ED, Taoudi S. Membrane budding is a major mechanism of in vivo platelet biogenesis. J Exp Med 2021; 217:151972. [PMID: 32706855 PMCID: PMC7478734 DOI: 10.1084/jem.20191206] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/16/2020] [Accepted: 06/11/2020] [Indexed: 12/12/2022] Open
Abstract
How platelets are produced by megakaryocytes in vivo remains controversial despite more than a century of investigation. Megakaryocytes readily produce proplatelet structures in vitro; however, visualization of platelet release from proplatelets in vivo has remained elusive. We show that within the native prenatal and adult environments, the frequency and rate of proplatelet formation is incompatible with the physiological demands of platelet replacement. We resolve this inconsistency by performing in-depth analysis of plasma membrane budding, a cellular process that has previously been dismissed as a source of platelet production. Our studies demonstrate that membrane budding results in the sustained release of platelets directly into the peripheral circulation during both fetal and adult life without induction of cell death or proplatelet formation. In support of this model, we demonstrate that in mice deficient for NF-E2 (the thrombopoietic master regulator), the absence of membrane budding correlates with failure of in vivo platelet production. Accordingly, we propose that membrane budding, rather than proplatelet formation, supplies the majority of the platelet biomass.
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Affiliation(s)
- Kathryn S Potts
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Alison Farley
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Caleb A Dawson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Joel Rimes
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Christine Biben
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Carolyn de Graaf
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Margaret A Potts
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Olivia J Stonehouse
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Amandine Carmagnac
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Pradnya Gangatirkar
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Emma C Josefsson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Casey Anttila
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Daniela Amann-Zalcenstein
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Shalin Naik
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Warren S Alexander
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Douglas J Hilton
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Edwin D Hawkins
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Samir Taoudi
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
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2
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Abstract
The KEAP1-NRF2 pathway is the principal protective response to oxidative and electrophilic stresses. Under homeostatic conditions, KEAP1 forms part of an E3 ubiquitin ligase, which tightly regulates the activity of the transcription factor NRF2 by targeting it for ubiquitination and proteasome-dependent degradation. In response to stress, an intricate molecular mechanism facilitated by sensor cysteines within KEAP1 allows NRF2 to escape ubiquitination, accumulate within the cell, and translocate to the nucleus, where it can promote its antioxidant transcription program. Recent advances have revealed that KEAP1 contains multiple stress sensors and inactivation modalities, which together allow diverse cellular inputs, from oxidative stress and cellular metabolites to dysregulated autophagy, to regulate NRF2 activity. This integration of the KEAP1-NRF2 system into multiple cellular signaling and metabolic pathways places NRF2 activation as a critical regulatory node in many disease phenotypes and suggests that the pharmaceutical modulation of NRF2's cytoprotective activity will be beneficial for human health in a broad range of noncommunicable diseases.
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3
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Tong DL, Kempsell KE, Szakmany T, Ball G. Development of a Bioinformatics Framework for Identification and Validation of Genomic Biomarkers and Key Immunopathology Processes and Controllers in Infectious and Non-infectious Severe Inflammatory Response Syndrome. Front Immunol 2020; 11:380. [PMID: 32318053 PMCID: PMC7147506 DOI: 10.3389/fimmu.2020.00380] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/17/2020] [Indexed: 12/12/2022] Open
Abstract
Sepsis is defined as dysregulated host response caused by systemic infection, leading to organ failure. It is a life-threatening condition, often requiring admission to an intensive care unit (ICU). The causative agents and processes involved are multifactorial but are characterized by an overarching inflammatory response, sharing elements in common with severe inflammatory response syndrome (SIRS) of non-infectious origin. Sepsis presents with a range of pathophysiological and genetic features which make clinical differentiation from SIRS very challenging. This may reflect a poor understanding of the key gene inter-activities and/or pathway associations underlying these disease processes. Improved understanding is critical for early differential recognition of sepsis and SIRS and to improve patient management and clinical outcomes. Judicious selection of gene biomarkers suitable for development of diagnostic tests/testing could make differentiation of sepsis and SIRS feasible. Here we describe a methodologic framework for the identification and validation of biomarkers in SIRS, sepsis and septic shock patients, using a 2-tier gene screening, artificial neural network (ANN) data mining technique, using previously published gene expression datasets. Eight key hub markers have been identified which may delineate distinct, core disease processes and which show potential for informing underlying immunological and pathological processes and thus patient stratification and treatment. These do not show sufficient fold change differences between the different disease states to be useful as primary diagnostic biomarkers, but are instrumental in identifying candidate pathways and other associated biomarkers for further exploration.
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Affiliation(s)
- Dong Ling Tong
- Artificial Intelligence Laboratory, Faculty of Engineering and Computing, First City University College, Petaling Jaya, Malaysia.,School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Karen E Kempsell
- Public Health England, National Infection Service, Porton Down, Salisbury, United Kingdom
| | - Tamas Szakmany
- Department of Anaesthesia Intensive Care and Pain Medicine, Division of Population Medicine, Cardiff University, Cardiff, United Kingdom
| | - Graham Ball
- School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
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4
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Cis-element architecture of Nrf2-sMaf heterodimer binding sites and its relation to diseases. Arch Pharm Res 2019; 43:275-285. [PMID: 31792803 DOI: 10.1007/s12272-019-01193-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/19/2019] [Indexed: 12/11/2022]
Abstract
Cellular detoxication is essential for health because it provides protection against various chemicals and xenobiotics. The KEAP1-NRF2 system is important for cellular defense against oxidative and electrophilic stresses as NRF2 activates the transcription of an array of cytoprotective genes, including drug-metabolizing and antioxidant enzymes, in a stress-dependent manner. The CNC family of transcription factors, including NRF2, form heterodimers with small Maf (sMaf) proteins and bind to consensus DNA sequences that have been referred to as antioxidant response element, electrophile response element, or NF-E2-binding element. These sequences are now collectively called CNC-sMaf binding element (CsMBE). In addition to forming a heterodimer with CNC proteins, sMaf proteins can form homodimers and recognize regulatory motifs called Maf recognition element (MARE). Although the CsMBE sequence substantially overlaps with that of MARE, the sequences differ. NRF2 selectively recognizes CsMBE, which is critical for cytoprotection. Recent advances in high-throughput sequencing and population-scale genome analysis provide new insights into the transcriptional regulation involved in the stress response. The integration of a genome-wide map of NRF2 occupancy with disease-susceptibility loci reveals the associations between polymorphisms in CsMBE and disease risk, information useful for the personalized medicine of the future.
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5
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Yamamoto M, Kensler TW, Motohashi H. The KEAP1-NRF2 System: a Thiol-Based Sensor-Effector Apparatus for Maintaining Redox Homeostasis. Physiol Rev 2018; 98:1169-1203. [PMID: 29717933 PMCID: PMC9762786 DOI: 10.1152/physrev.00023.2017] [Citation(s) in RCA: 1007] [Impact Index Per Article: 167.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Kelch-like ECH-associated protein 1-NF-E2-related factor 2 (KEAP1-NRF2) system forms the major node of cellular and organismal defense against oxidative and electrophilic stresses of both exogenous and endogenous origins. KEAP1 acts as a cysteine thiol-rich sensor of redox insults, whereas NRF2 is a transcription factor that robustly transduces chemical signals to regulate a battery of cytoprotective genes. KEAP1 represses NRF2 activity under quiescent conditions, whereas NRF2 is liberated from KEAP1-mediated repression on exposure to stresses. The rapid inducibility of a response based on a derepression mechanism is an important feature of the KEAP1-NRF2 system. Recent studies have unveiled the complexities of the functional contributions of the KEAP1-NRF2 system and defined its broader involvement in biological processes, including cell proliferation and differentiation, as well as cytoprotection. In this review, we describe historical milestones in the initial characterization of the KEAP1-NRF2 system and provide a comprehensive overview of the molecular mechanisms governing the functions of KEAP1 and NRF2, as well as their roles in physiology and pathology. We also refer to the clinical significance of the KEAP1-NRF2 system as an important prophylactic and therapeutic target for various diseases, particularly aging-related disorders. We believe that controlled harnessing of the KEAP1-NRF2 system is a key to healthy aging and well-being in humans.
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Sha Z, Schnell HM, Ruoff K, Goldberg A. Rapid induction of p62 and GABARAPL1 upon proteasome inhibition promotes survival before autophagy activation. J Cell Biol 2018. [PMID: 29535191 PMCID: PMC5940303 DOI: 10.1083/jcb.201708168] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cells are thought to adapt to proteasome inhibition by using alternative pathways for degradation such as autophagy. Sha et al. now report that cells rapidly induce GABARAPL1 and p62 upon proteasome inhibition, but this promotes cell survival by sequestering ubiquitinated and sumoylated proteins long before the cells induce other Atg genes and activate autophagy. Proteasome inhibitors are used as research tools and to treat multiple myeloma, and proteasome activity is diminished in several neurodegenerative diseases. We therefore studied how cells compensate for proteasome inhibition. In 4 h, proteasome inhibitor treatment caused dramatic and selective induction of GABARAPL1 (but not other autophagy genes) and p62, which binds ubiquitinated proteins and GABARAPL1 on autophagosomes. Knockdown of p62 or GABARAPL1 reduced cell survival upon proteasome inhibition. p62 induction requires the transcription factor nuclear factor (erythroid-derived 2)-like 1 (Nrf1), which simultaneously induces proteasome genes. After 20-h exposure to proteasome inhibitors, cells activated autophagy and expression of most autophagy genes by an Nrf1-independent mechanism. Although p62 facilitates the association of ubiquitinated proteins with autophagosomes, its knockdown in neuroblastoma cells blocked the buildup of ubiquitin conjugates in perinuclear aggresomes and of sumoylated proteins in nuclear inclusions but did not reduce the degradation of ubiquitinated proteins. Thus, upon proteasome inhibition, cells rapidly induce p62 expression, which enhances survival primarily by sequestering ubiquitinated proteins in inclusions.
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Affiliation(s)
- Zhe Sha
- Harvard Medical School, Boston, MA
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7
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Wysokinski WE, Tafur A, Wu Y, Ammash N, Asirvatham SJ, Gosk-Bierska I, Grill DE, Slusser JP, Mruk J, McBane RD. Platelet-predominate gene expression and reticulated platelets in nonvalvular atrial fibrillation: Effect of pulmonary veins isolation. J Cardiovasc Electrophysiol 2018; 29:412-420. [PMID: 29377394 DOI: 10.1111/jce.13438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/30/2017] [Accepted: 12/06/2017] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Reticulated platelet (RP) content is increased in nonvalvular atrial fibrillation (NVAF). The purpose of this study was to determine if platelet content, morphology, and RP proportion are modulated by platelet genes. METHODS AND RESULTS Expression of six platelet-predominate genes impacting platelet formation and release, platelet count, and RP content was assessed in NVAF patients before and 3-4 months after pulmonary veins isolation (PVI) and compared to normal sinus rhythm (NSR) controls. RNA from isolated platelets was reverse-transcribed assayed against selected genes utilizing real-time qPCR, and expressed as mean cycle threshold (ΔCt) using beta-2-microglobulin as endogenous control. RP content was assessed by flow cytometry. A fourfold lower expression of CFL1 gene coding for nonmuscle cofilin (7.8 ± 0.9 vs. 5.7 ± 1.6, P < 0.001) and twofold lower expression of four other genes were associated with similar platelet counts but fourfold higher (28.7+7.0 vs. 6.7+5.4, P < 0.001) RP content (%) in 97 NVAF cases compared to 51 NSR controls. Three to 4 months after PVI, RP decreased by 28%, while CFL1 gene expression increased over twofold but TUBA4A gene expression decreased almost twofold; NFE2 and MYL6 gene expression remained unchanged. CONCLUSIONS NVAF is associated with notable downregulation of genes directing platelet production and size but increased RP content. PVI impacts the expression of many of these genes, implying a direct relationship between atrial fibrillation and platelet biogenesis.
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Affiliation(s)
- Waldemar E Wysokinski
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Alfonso Tafur
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Yanhong Wu
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Naser Ammash
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Samuel J Asirvatham
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Izabela Gosk-Bierska
- Department of Angiology, Hypertension and Diabetology, Wroclaw Medical University, Wroclaw, Poland
| | - Diane E Grill
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Joshua P Slusser
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
| | - Jozef Mruk
- Department of Internal Medicine, University of Kansas School of Medicine-Wichita, Witchita, KS, USA.,Wichita Clinic, Wichita, KS, USA
| | - Robert D McBane
- Department of Cardiovascular Medicine, Mayo Clinic Foundation for Education and Research, Rochester, MN, USA
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8
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miR-128 Is Implicated in Stress Responses by Targeting MAFG in Skeletal Muscle Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9308310. [PMID: 29138682 PMCID: PMC5613631 DOI: 10.1155/2017/9308310] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/30/2017] [Accepted: 07/18/2017] [Indexed: 12/22/2022]
Abstract
MAFG (v-Maf avian musculoaponeurotic fibrosarcoma oncogene homolog G) is a bZIP-type transcriptional regulator that belongs to the small MAF (sMAFs) protein family. By interacting with other bZIP transcription factors, sMAFs can form homo- and heterodimers governing either repressive or activating transcriptional functions. As heterodimeric partner of Nrf2, MAFG positively influences the ARE-dependent antioxidant/xenobiotic pathways, at least in condition of a correct MAFG:Nrf2 balance. MicroRNAs (miRs) participate to different regulatory networks being involved as fine-tuning regulators of gene expression. However, the connections between cellular surveillance to stresses mediated by MAFG:Nrf2 and miR regulations are not well understood. Here, we explored the impact of miR-128 in expression of genes related to stress response. Bioinformatic predictions coupled with functional analysis revealed the presence of miR-128 binding site in the 3′UTR of MAFG. Ectopic miR-128 expression correlated with reduced expression of endogenous MAFG-dependent genes and negatively affected ARE-mediated molecular phenotype based on Nrf2 activity. Indeed, miR-128 impairs redox-dependent pathways induced in response to oxidative stress. Moreover, in condition of hypoxia, MAFG induction correlated with reduced levels of miR-128. This lead to increased mRNA levels of HMOX-1 and x-CT for blunting stress. Overall, these findings identify MAFG as novel direct target of miR-128.
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9
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Yang W, Wang J, Chen Z, Chen J, Meng Y, Chen L, Chang Y, Geng B, Sun L, Dou L, Li J, Guan Y, Cui Q, Yang J. NFE2 Induces miR-423-5p to Promote Gluconeogenesis and Hyperglycemia by Repressing the Hepatic FAM3A-ATP-Akt Pathway. Diabetes 2017; 66:1819-1832. [PMID: 28411267 DOI: 10.2337/db16-1172] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 04/07/2017] [Indexed: 11/13/2022]
Abstract
Hepatic FAM3A expression is repressed under obese conditions, but the underlying mechanism remains unknown. This study determined the role and mechanism of miR-423-5p in hepatic glucose and lipid metabolism by repressing FAM3A expression. miR-423-5p expression was increased in the livers of obese diabetic mice and in patients with nonalcoholic fatty liver disease (NAFLD) with decreased FAM3A expression. miR-423-5p directly targeted FAM3A mRNA to repress its expression and the FAM3A-ATP-Akt pathway in cultured hepatocytes. Hepatic miR-423-5p inhibition suppressed gluconeogenesis and improved insulin resistance, hyperglycemia, and fatty liver in obese diabetic mice. In contrast, hepatic miR-423-5p overexpression promoted gluconeogenesis and hyperglycemia and increased lipid deposition in normal mice. miR-423-5p inhibition activated the FAM3A-ATP-Akt pathway and repressed gluconeogenic and lipogenic gene expression in diabetic mouse livers. The miR-423 precursor gene was further shown to be a target gene of NFE2, which induced miR-423-5p expression to repress the FAM3A-ATP-Akt pathway in cultured hepatocytes. Hepatic NFE2 overexpression upregulated miR-423-5p to repress the FAM3A-ATP-Akt pathway, promoting gluconeogenesis and lipid deposition and causing hyperglycemia in normal mice. In conclusion, under the obese condition, activation of the hepatic NFE2/miR-423-5p axis plays important roles in the progression of type 2 diabetes and NAFLD by repressing the FAM3A-ATP-Akt signaling pathway.
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Affiliation(s)
- Weili Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Junpei Wang
- Department of Biomedical Informatics, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Zhenzhen Chen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
- Department of Biomedical Informatics, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Ji Chen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Yuhong Meng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Liming Chen
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, China
| | - Yongsheng Chang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bin Geng
- Hypertension Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Libo Sun
- Beijing You An Hospital, Capital Medical University, Beijing, China
| | - Lin Dou
- Key Laboratory of Geriatrics, Beijing Institute of Geriatrics & Beijing Hospital, Ministry of Health, Beijing, China
| | - Jian Li
- Key Laboratory of Geriatrics, Beijing Institute of Geriatrics & Beijing Hospital, Ministry of Health, Beijing, China
| | - Youfei Guan
- Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
| | - Qinghua Cui
- Department of Biomedical Informatics, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Jichun Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
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10
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A Homeostatic Shift Facilitates Endoplasmic Reticulum Proteostasis through Transcriptional Integration of Proteostatic Stress Response Pathways. Mol Cell Biol 2017; 37:MCB.00439-16. [PMID: 27920251 DOI: 10.1128/mcb.00439-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/23/2016] [Indexed: 01/01/2023] Open
Abstract
Eukaryotic cells maintain protein homeostasis through the activity of multiple basal and inducible systems, which function in concert to allow cells to adapt to a wide range of environmental conditions. Although the transcriptional programs regulating individual pathways have been studied in detail, it is not known how the different pathways are transcriptionally integrated such that a deficiency in one pathway can be compensated by a change in an auxiliary response. One such pathway that plays an essential role in many proteostasis responses is the ubiquitin-proteasome system, which functions to degrade damaged, unfolded, or short half-life proteins. Transcriptional regulation of the proteasome is mediated by the transcription factor Nrf1. Using a conditional knockout mouse model, we found that Nrf1 regulates protein homeostasis in the endoplasmic reticulum (ER) through transcriptional regulation of the ER stress sensor ATF6. In Nrf1 conditional-knockout mice, a reduction in proteasome activity is accompanied by an ATF6-dependent downregulation of the endoplasmic reticulum-associated degradation machinery, which reduces the substrate burden on the proteasome. This indicates that Nrf1 regulates a homeostatic shift through which proteostasis in the endoplasmic reticulum and cytoplasm are coregulated based on a cell's ability to degrade proteins.
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11
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Basak P, Sadhukhan P, Sarkar P, Sil PC. Perspectives of the Nrf-2 signaling pathway in cancer progression and therapy. Toxicol Rep 2017; 4:306-318. [PMID: 28959654 PMCID: PMC5615147 DOI: 10.1016/j.toxrep.2017.06.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/18/2017] [Accepted: 06/07/2017] [Indexed: 12/12/2022] Open
Abstract
The Nuclear factor erythroid2-related factor2 (Nrf2), a master regulator of redox homoeostasis, is a key transcription factor regulating a wide array of genes for antioxidant and detoxification enzymes. It protects organs from various kinds of toxic insults. On the other hand, activation of Nrf2 is also correlated with cancer progression and chemoresistance. Downregulation of Nrf2 activity has attracted an increasing amount of attention as it may provide an alternative cancer therapy. In this review, we examine recent studies on roles of Nrf2 in several pathophysiological conditions emphasising cancer. We discuss elaborately the current knowledge on Nrf2 regulation including KEAP1-dependent and KEAP1-independent cascades. KEAP1/Nrf2 system is a master regulator of cellular response against a variety of environmental stresses. We also highlight several tightly controlled regulations of Nrf2 by numerous proteins, small molecules, toxic metals, etc. In addition, we evaluate the possible therapeutic approaches of increasing chemosensitivity via modulating Nrf2 signaling.
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12
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Williams LM, Lago BA, McArthur AG, Raphenya AR, Pray N, Saleem N, Salas S, Paulson K, Mangar RS, Liu Y, Vo AH, Shavit JA. The transcription factor, Nuclear factor, erythroid 2 (Nfe2), is a regulator of the oxidative stress response during Danio rerio development. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 180:141-154. [PMID: 27716579 PMCID: PMC5274700 DOI: 10.1016/j.aquatox.2016.09.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 09/28/2016] [Accepted: 09/30/2016] [Indexed: 05/17/2023]
Abstract
Development is a complex and well-defined process characterized by rapid cell proliferation and apoptosis. At this stage in life, a developmentally young organism is more sensitive to toxicants as compared to an adult. In response to pro-oxidant exposure, members of the Cap'n'Collar (CNC) basic leucine zipper (b-ZIP) transcription factor family (including Nfe2 and Nfe2-related factors, Nrfs) activate the expression of genes whose protein products contribute to reduced toxicity. Here, we studied the role of the CNC protein, Nfe2, in the developmental response to pro-oxidant exposure in the zebrafish (Danio rerio). Following acute waterborne exposures to diquat or tert-buytlhydroperoxide (tBOOH) at one of three developmental stages, wildtype (WT) and nfe2 knockout (KO) embryos and larvae were morphologically scored and their transcriptomes sequenced. Early in development, KO animals suffered from hypochromia that was made more severe through exposure to pro-oxidants; this phenotype in the KO may be linked to decreased expression of alas2, a gene involved in heme synthesis. WT and KO eleutheroembryos and larvae were phenotypically equally affected by exposure to pro-oxidants, where tBOOH caused more pronounced phenotypes as compared to diquat. Comparing diquat and tBOOH exposed embryos relative to the WT untreated control, a greater number of genes were up-regulated in the tBOOH condition as compared to diquat (tBOOH: 304 vs diquat: 148), including those commonly found to be differentially regulated in the vertebrate oxidative stress response (OSR) (e.g. hsp70.2, txn1, and gsr). When comparing WT and KO across all treatments and times, there were 1170 genes that were differentially expressed, of which 33 are known targets of the Nrf proteins Nrf1 and Nrf2. More specifically, in animals exposed to pro-oxidants a total of 968 genes were differentially expressed between WT and KO across developmental time, representing pathways involved in coagulation, embryonic organ development, body fluid level regulation, erythrocyte differentiation, and oxidation-reduction, amongst others. The greatest number of genes that changed in expression between WT and KO occurred in animals exposed to diquat at 2h post fertilization (hpf). Across time and treatment, there were six genes (dhx40, cfap70, dnajb9b, slc35f4, spi-c, and gpr19) that were significantly up-regulated in KO compared to WT and four genes (fhad1, cyp4v7, nlrp12, and slc16a6a) that were significantly down-regulated. None of these genes have been previously identified as targets of Nfe2 or the Nrf family. These results demonstrate that the zebrafish Nfe2 may be a regulator of both primitive erythropoiesis and the OSR during development.
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Affiliation(s)
- Larissa M Williams
- Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240, USA; The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA, USA.
| | - Briony A Lago
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1, Canada.
| | - Andrew G McArthur
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1, Canada.
| | - Amogelang R Raphenya
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1, Canada.
| | - Nicholas Pray
- Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240, USA.
| | - Nabil Saleem
- Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240, USA; The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA, USA.
| | - Sophia Salas
- Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240, USA; The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA, USA.
| | - Katherine Paulson
- Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240, USA; The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA, USA.
| | - Roshni S Mangar
- The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA, USA; College of the Atlantic, 105 Eden Street, Bar Harbor, ME 04609, USA.
| | - Yang Liu
- Department of Pediatrics and Communicable Diseases, University of Michigan, 8200 MSRB III 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Andy H Vo
- Department of Pediatrics and Communicable Diseases, University of Michigan, 8200 MSRB III 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Jordan A Shavit
- Department of Pediatrics and Communicable Diseases, University of Michigan, 8200 MSRB III 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
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13
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Abstract
Reactive oxygen species (ROS), which are both a natural byproduct of oxidative metabolism and an undesirable byproduct of many environmental stressors, can damage all classes of cellular macromolecules and promote diseases from cancer to neurodegeneration. The actions of ROS are mitigated by the transcription factor NRF2, which regulates expression of antioxidant genes via its interaction with cis-regulatory antioxidant response elements (AREs). However, despite the seemingly straightforward relationship between the opposing forces of ROS and NRF2, regulatory precision in the NRF2 network is essential. Genetic variants that alter NRF2 stability or alter ARE sequences have been linked to a range of diseases. NRF2 hyperactivating mutations are associated with tumorigenesis. On the subtler end of the spectrum, single nucleotide variants (SNVs) that alter individual ARE sequences have been linked to neurodegenerative disorders including progressive supranuclear palsy and Parkinson’s disease, as well as other diseases. Although the human health implications of NRF2 dysregulation have been recognized for some time, a systems level view of this regulatory network is beginning to highlight key NRF2-targeted AREs consistently associated with disease.
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14
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Zang C, Luyten A, Chen J, Liu XS, Shivdasani RA. NF-E2, FLI1 and RUNX1 collaborate at areas of dynamic chromatin to activate transcription in mature mouse megakaryocytes. Sci Rep 2016; 6:30255. [PMID: 27457419 PMCID: PMC4960521 DOI: 10.1038/srep30255] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/01/2016] [Indexed: 12/16/2022] Open
Abstract
Mutations in mouse and human Nfe2, Fli1 and Runx1 cause thrombocytopenia. We applied genome-wide chromatin dynamics and ChIP-seq to determine these transcription factors’ (TFs) activities in terminal megakaryocyte (MK) maturation. Enhancers with H3K4me2-marked nucleosome pairs were most enriched for NF-E2, FLI and RUNX sequence motifs, suggesting that this TF triad controls much of the late MK program. ChIP-seq revealed NF-E2 occupancy near previously implicated target genes, whose expression is compromised in Nfe2-null cells, and many other genes that become active late in MK differentiation. FLI and RUNX were also the motifs most enriched near NF-E2 binding sites and ChIP-seq implicated FLI1 and RUNX1 in activation of late MK, including NF-E2-dependent, genes. Histones showed limited activation in regions of single TF binding, while enhancers that bind NF-E2 and either RUNX1, FLI1 or both TFs gave the highest signals for TF occupancy and H3K4me2; these enhancers associated best with genes activated late in MK maturation. Thus, three essential TFs co-occupy late-acting cis-elements and show evidence for additive activity at genes responsible for platelet assembly and release. These findings provide a rich dataset of TF and chromatin dynamics in primary MK and explain why individual TF losses cause thrombopocytopenia.
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Affiliation(s)
- Chongzhi Zang
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard T.H. Chan School of Public Health, Boston, MA 02215, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Annouck Luyten
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Justina Chen
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - X Shirley Liu
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard T.H. Chan School of Public Health, Boston, MA 02215, USA.,Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Ramesh A Shivdasani
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.,Department of Pediatric Hematology/Oncology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
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15
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Small Maf proteins (MafF, MafG, MafK): History, structure and function. Gene 2016; 586:197-205. [PMID: 27058431 DOI: 10.1016/j.gene.2016.03.058] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/11/2016] [Accepted: 03/30/2016] [Indexed: 12/12/2022]
Abstract
The small Maf proteins (sMafs) are basic region leucine zipper (bZIP)-type transcription factors. The basic region of the Maf family is unique among the bZIP factors, and it contributes to the distinct DNA-binding mode of this class of proteins. MafF, MafG and MafK are the three vertebrate sMafs, and no functional differences have been observed among them in terms of their bZIP structures. sMafs form homodimers by themselves, and they form heterodimers with cap 'n' collar (CNC) proteins (p45 NF-E2, Nrf1, Nrf2, and Nrf3) and also with Bach proteins (Bach1 and Bach2). Because CNC and Bach proteins cannot bind to DNA as monomers, sMafs are indispensable partners that are required by CNC and Bach proteins to exert their functions. sMafs lack the transcriptional activation domain; hence, their homodimers act as transcriptional repressors. In contrast, sMafs participate in transcriptional activation or repression depending on their heterodimeric partner molecules and context. Mouse genetic analyses have revealed that various biological pathways are under the regulation of CNC-sMaf heterodimers. In this review, we summarize the history and current progress of sMaf studies in relation to their partners.
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16
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Park HJ, Jung ES, Kong KA, Park EM, Cheon JH, Choi JH. Identification of OCTN2 variants and their association with phenotypes of Crohn's disease in a Korean population. Sci Rep 2016; 6:22887. [PMID: 26965072 PMCID: PMC4786794 DOI: 10.1038/srep22887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/23/2016] [Indexed: 12/19/2022] Open
Abstract
Crohn’s disease (CD) is a chronic inflammatory bowel disease and a genetic variant in the OCTN2, g.-207G > C is significantly associated with CD susceptibility. This study was aimed to identify novel OCTN2 functional promoter variants and their roles in transcriptional regulation using various in vitro assays. In addition, we investigated the association between OCTN2 genotypes and CD through genetic analysis using DNA samples from 193 patients with CD and 281 healthy controls. Among the three major promoter haplotypes of OCTN2 identified, one haplotype, H3, showed a significant decrease in promoter activity: two polymorphisms in H3 were associated with a significant reduction in promoter activity. In particular, we found that the reduced transcriptional activity of those two polymorphisms results from a reduction in the binding affinity of the activators, NF-E2 and YY1, to the OCTN2 promoter. The functional haplotype of the OCTN2 promoter was associated with clinical course of CD such as the disease behavior and need for surgery. However, genetic variants or haplotypes of OCTN2 did not affect the susceptibility to CD. Our results suggest that a common promoter haplotype of OCTN2 regulates the transcriptional rate of OCTN2 and influences the clinical course of CD.
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Affiliation(s)
- Hyo Jin Park
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, 07985, Korea
| | - Eun Suk Jung
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, Korea.,Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Kyoung Ae Kong
- Clinical Trial Center, Ewha Womans University Medical Center, Seoul, 07985, Korea
| | - Eun-Mi Park
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, 07985, Korea
| | - Jae Hee Cheon
- Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Ji Ha Choi
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, 07985, Korea
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17
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Xing Y, Zhang J, Lu L, Li D, Wang Y, Huang S, Li C, Zhang Z, Li J, Meng A. Identification of hub genes of pneumocyte senescence induced by thoracic irradiation using weighted gene co‑expression network analysis. Mol Med Rep 2015; 13:107-16. [PMID: 26572216 PMCID: PMC4686054 DOI: 10.3892/mmr.2015.4566] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 10/14/2015] [Indexed: 01/03/2023] Open
Abstract
Irradiation commonly causes pneumocyte senescence, which may lead to severe fatal lung injury characterized by pulmonary dysfunction and respiratory failure. However, the molecular mechanism underlying the induction of pneumocyte senescence by irradiation remains to be elucidated. In the present study, weighted gene co-expression network analysis (WGCNA) was used to screen for differentially expressed genes, and to identify the hub genes and gene modules, which may be critical for senescence. A total of 2,916 differentially expressed genes were identified between the senescence and non-senescence groups following thoracic irradiation. In total, 10 gene modules associated with cell senescence were detected, and six hub genes were identified, including B-cell scaffold protein with ankyrin repeats 1, translocase of outer mitochondrial membrane 70 homolog A, actin filament-associated protein 1, Cd84, Nuf2 and nuclear factor erythroid 2. These genes were markedly associated with cell proliferation, cell division and cell cycle arrest. The results of the present study demonstrated that WGCNA of microarray data may provide further insight into the molecular mechanism underlying pneumocyte senescence.
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Affiliation(s)
- Yonghua Xing
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Junling Zhang
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Lu Lu
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Deguan Li
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Yueying Wang
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Song Huang
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Chengcheng Li
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Zhubo Zhang
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Jianguo Li
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
| | - Aimin Meng
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, Nankai, Tianjin 300192, P.R. China
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18
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Murakami S, Motohashi H. Roles of Nrf2 in cell proliferation and differentiation. Free Radic Biol Med 2015; 88:168-178. [PMID: 26119783 DOI: 10.1016/j.freeradbiomed.2015.06.030] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/18/2015] [Accepted: 06/22/2015] [Indexed: 02/07/2023]
Abstract
The Keap1-Nrf2 system plays pivotal roles in defense mechanisms by regulating cellular redox homeostasis. Nrf2 is an inducible transcription factor that activates a battery of genes encoding antioxidant proteins and phase II enzymes in response to oxidative stress and electrophilic xenobiotics. The activity of Nrf2 is regulated by Keap1, which promotes the ubiquitination and subsequent degradation of Nrf2 under normal conditions and releases the inhibited Nrf2 activity upon exposure to the stresses. Though an impressive contribution of the Keap1-Nrf2 system to the protection from exogenous and endogenous electrophilic insults has been well established, a line of evidence has suggested that the Keap1-Nrf2 system has various novel functions, particularly in cell proliferation and differentiation. Because the proliferation and differentiation of diverse cell types are often influenced and modulated by the cellular redox balance, Nrf2 has been considered to control these cellular processes by regulating the cellular levels of reactive oxygen species (ROS). In addition, analyses of the genome-wide distribution of Nrf2 have identified new sets of Nrf2 target genes whose products are involved in cell proliferation and differentiation but not necessarily in the regulation of oxidative stress. Considering the most characteristic features of Nrf2 as an inducible transcription factor, a newly emerged concept proposes that the Keap1-Nrf2 system translates environmental stresses into regulatory network signals in cell fate determination. In this review, we introduce the contribution of Nrf2 to lineage-specific differentiation, maintenance and differentiation of stem cells, and proliferation of normal and cancer cells, and we discuss how the response to fluctuating environments modulates cell behavior through the Keap1-Nrf2 system.
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Affiliation(s)
- Shohei Murakami
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Hozumi Motohashi
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
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19
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Gasiorek JJ, Blank V. Regulation and function of the NFE2 transcription factor in hematopoietic and non-hematopoietic cells. Cell Mol Life Sci 2015; 72:2323-35. [PMID: 25721735 PMCID: PMC11114048 DOI: 10.1007/s00018-015-1866-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/27/2015] [Accepted: 02/16/2015] [Indexed: 01/01/2023]
Abstract
The NFE2 transcription factor was identified over 25 years ago. The NFE2 protein forms heterodimers with small MAF proteins, and the resulting complex binds to regulatory elements in a large number of target genes. In contrast to other CNC transcription family members including NFE2L1 (NRF1), NFE2L2 (NRF2) and NFE2L3 (NRF3), which are widely expressed, earlier studies had suggested that the major sites of NFE2 expression are hematopoietic cells. Based on cell culture studies it was proposed that this protein acts as a critical regulator of globin gene expression. However, the knockout mouse model displayed only mild erythroid abnormalities, while the major phenotype was a defect in megakaryocyte biogenesis. Indeed, absence of NFE2 led to severely impaired platelet production. A series of recent data, also summarized here, shed new light on the various functional roles of NFE2 and the regulation of its activity. NFE2 is part of a complex regulatory network, including transcription factors such as GATA1 and RUNX1, controlling megakaryocytic and/or erythroid cell function. Surprisingly, it was recently found that NFE2 also has a role in non-hematopoietic tissues, such as the trophoblast, in which it is also expressed, as well as the bone, opening the door to new research areas for this transcription factor. Additional data showed that NFE2 function is controlled by a series of posttranslational modifications. Important strides have been made with respect to the clinical significance of NFE2, linking this transcription factor to hematological disorders such as polycythemias.
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Affiliation(s)
- Jadwiga J. Gasiorek
- Lady Davis Institute for Medical Research, McGill University, 3755 Chemin de la Côte Sainte-Catherine, Montreal, QC H3T 1E2 Canada
- Department of Medicine, McGill University, Montreal, QC Canada
| | - Volker Blank
- Lady Davis Institute for Medical Research, McGill University, 3755 Chemin de la Côte Sainte-Catherine, Montreal, QC H3T 1E2 Canada
- Department of Medicine, McGill University, Montreal, QC Canada
- Department of Physiology, McGill University, Montreal, QC Canada
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20
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Sp1/Sp3 transcription factors regulate hallmarks of megakaryocyte maturation and platelet formation and function. Blood 2014; 125:1957-67. [PMID: 25538045 DOI: 10.1182/blood-2014-08-593343] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Sp1 and Sp3 belong to the specificity proteins (Sp)/Krüppel-like transcription factor family. They are closely related, ubiquitously expressed, and recognize G-rich DNA motifs. They are thought to regulate generic processes such as cell-cycle and growth control, metabolic pathways, and apoptosis. Ablation of Sp1 or Sp3 in mice is lethal, and combined haploinsufficiency results in hematopoietic defects during the fetal stages. Here, we show that in adult mice, conditional pan-hematopoietic (Mx1-Cre) ablation of either Sp1 or Sp3 has minimal impact on hematopoiesis, whereas the simultaneous loss of Sp1 and Sp3 results in severe macrothrombocytopenia. This occurs in a cell-autonomous manner as shown by megakaryocyte-specific (Pf4-Cre) double-knockout mice. We employed flow cytometry, cell culture, and electron microscopy and show that although megakaryocyte numbers are normal in bone marrow and spleen, they display a less compact demarcation membrane system and a striking inability to form proplatelets. Through megakaryocyte transcriptomics and platelet proteomics, we identified several cytoskeleton-related proteins and downstream effector kinases, including Mylk, that were downregulated upon Sp1/Sp3 depletion, providing an explanation for the observed defects in megakaryopoiesis. Supporting this notion, selective Mylk inhibition by ML7 affected proplatelet formation and stabilization and resulted in defective ITAM receptor-mediated platelet aggregation.
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21
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Anani M, Nobuhisa I, Osawa M, Iwama A, Harada K, Saito K, Taga T. Sox17 as a candidate regulator of myeloid restricted differentiation potential. Dev Growth Differ 2014; 56:469-79. [PMID: 25093513 DOI: 10.1111/dgd.12147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 05/27/2014] [Accepted: 06/01/2014] [Indexed: 12/19/2022]
Abstract
Sry related high mobility group box 17 (Sox17), which is a marker of endodermal cells and a transcriptional regulator, has a critical role in the maintenance of fetal and neonatal hematopoietic stem cells (HSC). Sox17 has been identified as a key regulator of the development and differentiation of fetal hematopoietic progenitors from the aorta-gonad-mesonephros (AGM) region. The co-culture of Sox17-transduced hematopoietic progenitor cells (CD45(low) c-Kit(high) cells) from AGM regions on OP9 stromal cells gives rise to multipotential hematopoietic stem/progenitor cells. Here, we show that in a primary transplantation experiment, Sox17-transduction in CD45(low) c-Kit(high) cells of embryonic day (E) 10.5 AGM increased the absolute number of common myeloid progenitors (CMPs) in the bone marrow (BM) of recipient mice in comparison to that of granulocyte/macrophage progenitors (GMPs) and the megakaryocyte/erythroid progenitors (MEPs). When Sox17-transduced cells were cultured with OP9 stromal cells, Sox17-transduced GMPs (Sox17-GMPs), Sox17-transduced CMPs (Sox17-CMPs), and Sox17-transduced MEPs (Sox17-MEPs) were generated. Sox17-GMPs and Sox17-CMPs maintained their self-renewal capacity and the hematopoietic ability upon co-culture with the OP9 stromal cells for some passages. Moreover, Sox17-GMPs exhibited the increase in expression of c-Mpl and GATA-2 in comparison to GMPs of BM and Sox17-CMPs showed the increase in expression of c-Mpl, NF-E2, and β-globin genes in comparison to CMPs of BM. Furthermore, when Sox17-transduced cells were cultured in methylcellulose to examine the colony-forming ability, Sox17-GMPs and Sox17-CMPs maintained the formation of mixed colonies for some passages. Taken together, Sox17 is suggested to regulate the maintenance and differentiation of hematopoietic progenitors derived from AGM regions at midgestation, in particular myeloid progenitors.
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Affiliation(s)
- Maha Anani
- Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan; Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, 4.5 Km the Ring Road, Ismailia, 41522, Egypt
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22
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Glembotsky AC, Bluteau D, Espasandin YR, Goette NP, Marta RF, Marin Oyarzun CP, Korin L, Lev PR, Laguens RP, Molinas FC, Raslova H, Heller PG. Mechanisms underlying platelet function defect in a pedigree with familial platelet disorder with a predisposition to acute myelogenous leukemia: potential role for candidate RUNX1 targets. J Thromb Haemost 2014; 12:761-72. [PMID: 24606315 DOI: 10.1111/jth.12550] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 01/14/2023]
Abstract
BACKGROUND Familial platelet disorder with a predisposition to acute myelogenous leukemia (FPD/AML) is an inherited platelet disorder caused by a germline RUNX1 mutation and characterized by thrombocytopenia, a platelet function defect, and leukemia predisposition. The mechanisms underlying FPD/AML platelet dysfunction remain incompletely clarified. We aimed to determine the contribution of platelet structural abnormalities and defective activation pathways to the platelet phenotype. In addition, by using a candidate gene approach, we sought to identify potential RUNX1-regulated genes involved in these defects. METHODS Lumiaggregometry, α-granule and dense granule content and release, platelet ultrastructure, αIIb β3 integrin activation and outside-in signaling were assessed in members of one FPD/AML pedigree. Expression levels of candidate genes were measured and luciferase reporter assays and chromatin immunoprecipitation were performed to study NF-E2 regulation by RUNX1. RESULTS A severe decrease in platelet aggregation, defective αIIb β3 integrin activation and combined αδ storage pool deficiency were found. However, whereas the number of dense granules was markedly reduced, α-granule content was heterogeneous. A trend towards decreased platelet spreading was found, and β3 integrin phosphorylation was impaired, reflecting altered outside-in signaling. A decrease in the level of transcription factor p45 NF-E2 was shown in platelet RNA and lysates, and other deregulated genes included RAB27B and MYL9. RUNX1 was shown to bind to the NF-E2 promoter in primary megakaryocytes, and wild-type RUNX1, but not FPD/AML mutants, was able to activate NF-E2 expression. CONCLUSIONS The FPD/AML platelet function defect represents a complex trait, and RUNX1 orchestrates platelet function by regulating diverse aspects of this process. This study highlights the RUNX1 target NF-E2 as part of the molecular network by which RUNX1 regulates platelet biogenesis and function.
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Affiliation(s)
- A C Glembotsky
- Departamento de Hematología Investigación, Instituto de Investigaciones Médicas Alfredo Lanari, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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23
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Avanzi MP, Goldberg F, Davila J, Langhi D, Chiattone C, Mitchell WB. Rho kinase inhibition drives megakaryocyte polyploidization and proplatelet formation through MYC and NFE2 downregulation. Br J Haematol 2014; 164:867-76. [PMID: 24383889 DOI: 10.1111/bjh.12709] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/08/2013] [Indexed: 01/08/2023]
Abstract
The processes of megakaryocyte polyploidization and demarcation membrane system (DMS) formation are crucial for platelet production, but the mechanisms controlling these processes are not fully determined. Inhibition of Rho kinase (ROCK) signalling leads to increased polyploidization in umbilical cord blood-derived megakaryocytes. To extend these findings we determined the effect of ROCK inhibition on development of the DMS and on proplatelet formation. The underlying mechanisms were explored by analysing the effect of ROCK inhibition on the expression of MYC and NFE2, which encode two transcription factors critical for megakaryocyte development. ROCK inhibition promoted DMS formation, and increased proplatelet formation and platelet release. Rho kinase inhibition also downregulated MYC and NFE2 expression in mature megakaryocytes, and this down-regulation correlated with increased proplatelet formation. Our findings suggest a model whereby ROCK inhibition drives polyploidization, DMS growth and proplatelet formation late in megakaryocyte maturation through downregulation of MYC and NFE2 expression.
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Affiliation(s)
- Mauro P Avanzi
- Platelet Biology Laboratory, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA; Cellular Therapy Laboratory, Hematology Division, Santa Casa Medical School, São Paulo, Brazil
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