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Morin G, Pinel K, Heraud C, Le-Garrec S, Wayman C, Dias K, Terrier F, Lanuque A, Fontagné-Dicharry S, Seiliez I, Beaumatin F. Precision formulation, a new concept to improve dietary amino acid absorption based on the study of cationic amino acid transporters. iScience 2024; 27:108894. [PMID: 38318367 PMCID: PMC10839688 DOI: 10.1016/j.isci.2024.108894] [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: 07/11/2023] [Revised: 10/02/2023] [Accepted: 01/09/2024] [Indexed: 02/07/2024] Open
Abstract
Amino acid (AA) transporters (AAT) control AA cellular fluxes across membranes, contributing to maintain cellular homeostasis. In this study, we took advantage of rainbow trout metabolic feature, which highly relies on dietary AA, to explore the cellular and physiological consequences of unbalanced diets on AAT dysregulations with a particular focus on cationic AAs (CAA), frequently underrepresented in plant-based diets. Results evidenced that 24 different CAAT are expressed in various trout tissues, part of which being subjected to AA- and CAA-dependent regulations, with y+LAT2 exchanger being prone to the strongest dysregulations. Moreover, CAA were shown to control two major AA-dependent activation pathways (namely mTOR and GCN2) but at different strength according to the CAA considered. A new feed formulation strategy has been put forward to improve specifically the CAA supplemented absorption in fish together with their growth performance. Such "precision formulation" strategy reveals high potential for nutrition practices, especially in aquaculture.
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Affiliation(s)
- Guillaume Morin
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Karine Pinel
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Cécile Heraud
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Soizig Le-Garrec
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Chloé Wayman
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Karine Dias
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Frédéric Terrier
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Anthony Lanuque
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | | | - Iban Seiliez
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
| | - Florian Beaumatin
- Université de Pau et des Pays de l’Adour, E2S UPPA, INRAE, NUMEA, Saint-Pée-sur-Nivelle, France
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2
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Osman A, Lindén M, Österlund T, Vannas C, Andersson L, Escobar M, Ståhlberg A, Åman P. Identification of genomic binding sites and direct target genes for the transcription factor DDIT3/CHOP. Exp Cell Res 2023; 422:113418. [PMID: 36402425 DOI: 10.1016/j.yexcr.2022.113418] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/03/2022] [Accepted: 11/10/2022] [Indexed: 11/18/2022]
Abstract
DDIT3 is a tightly regulated basic leucine zipper (bZIP) transcription factor and key regulator in cellular stress responses. It is involved in a variety of pathological conditions and may cause cell cycle block and apoptosis. It is also implicated in differentiation of some specialized cell types and as an oncogene in several types of cancer. DDIT3 was originally believed to act as a dominant-negative inhibitor by forming heterodimers with other bZIP transcription factors, preventing their DNA binding and transactivating functions. DDIT3 has, however, been reported to bind DNA and regulate target genes. Here, we employed ChIP sequencing combined with microarray-based expression analysis to identify direct binding motifs and target genes of DDIT3. The results reveal DDIT3 binding to motifs similar to other bZIP transcription factors, known to form heterodimers with DDIT3. Binding to a class III satellite DNA repeat sequence was also detected. DDIT3 acted as a DNA-binding transcription factor and bound mainly to the promotor region of regulated genes. ChIP sequencing analysis of histone H3K27 methylation and acetylation showed a strong overlap between H3K27-acetylated marks and DDIT3 binding. These results support a role for DDIT3 as a transcriptional regulator of H3K27ac-marked genes in transcriptionally active chromatin.
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Affiliation(s)
- Ayman Osman
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Malin Lindén
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Tobias Österlund
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden; Region Västra Götaland, Sahlgrenska University Hospital, Department of Clinical Genetics and Genomics, Gothenburg, Sweden
| | - Christoffer Vannas
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lisa Andersson
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Mandy Escobar
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Ståhlberg
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden; Region Västra Götaland, Sahlgrenska University Hospital, Department of Clinical Genetics and Genomics, Gothenburg, Sweden
| | - Pierre Åman
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, Department of Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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3
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Are the Main Methionine Sources Equivalent? A Focus on DL-Methionine and DL-Methionine Hydroxy Analog Reveals Differences on Rainbow Trout Hepatic Cell Lines Functions. Int J Mol Sci 2022; 23:ijms23062935. [PMID: 35328356 PMCID: PMC8954868 DOI: 10.3390/ijms23062935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/01/2022] [Accepted: 03/05/2022] [Indexed: 01/27/2023] Open
Abstract
The replacement of fishmeal by plant proteins in aquafeeds imposes the use of synthetic methionine (MET) sources to balance the amino acid composition of alternative diets and so to meet the metabolic needs of fish of agronomic interest such as rainbow trout (RT-Oncorhynchus mykiss). Nonetheless, debates still exist to determine if one MET source is more efficiently used than another by fish. To address this question, the use of fish cell lines appeared a convenient strategy, since it allowed to perfectly control cell growing conditions notably by fully depleting MET from the media and studying which MET source is capable to restore cell growth/proliferation and metabolism when supplemented back. Thus, results of cell proliferation assays, Western blots, RT-qPCR and liquid chromatography analyses from two RT liver-derived cell lines revealed a better absorption and metabolization of DL-MET than DL-Methionine Hydroxy Analog (MHA) with the activation of the mechanistic Target Of Rapamycin (mTOR) pathway for DL-MET and the activation of integrated stress response (ISR) pathway for MHA. Altogether, the results clearly allow to conclude that both synthetic MET sources are not biologically equivalent, suggesting similar in vivo effects in RT liver and, therefore, questioning the MHA efficiencies in other RT tissues.
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Brocard M, Lu J, Hall B, Borah K, Moller-Levet C, Georgana I, Sorgeloos F, Beste DJV, Goodfellow IG, Locker N. Murine Norovirus Infection Results in Anti-inflammatory Response Downstream of Amino Acid Depletion in Macrophages. J Virol 2021; 95:e0113421. [PMID: 34346771 PMCID: PMC8475529 DOI: 10.1128/jvi.01134-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/13/2022] Open
Abstract
Murine norovirus (MNV) infection results in a late translation shutoff that is proposed to contribute to the attenuated and delayed innate immune response observed both in vitro and in vivo. Recently, we further demonstrated the activation of the α subunit of eukaryotic initiation factor 2 (eIF2α) kinase GCN2 during MNV infection, which has been previously linked to immunomodulation and resistance to inflammatory signaling during metabolic stress. While viral infection is usually associated with activation of double-stranded RNA (dsRNA) binding pattern recognition receptor PKR, we hypothesized that the establishment of a metabolic stress in infected cells is a proviral event, exploited by MNV to promote replication through weakening the activation of the innate immune response. In this study, we used multi-omics approaches to characterize cellular responses during MNV replication. We demonstrate the activation of pathways related to the integrated stress response, a known driver of anti-inflammatory phenotypes in macrophages. In particular, MNV infection causes an amino acid imbalance that is associated with GCN2 and ATF2 signaling. Importantly, this reprogramming lacks the features of a typical innate immune response, with the ATF/CHOP target GDF15 contributing to the lack of antiviral responses. We propose that MNV-induced metabolic stress supports the establishment of host tolerance to viral replication and propagation. IMPORTANCE During viral infection, host defenses are typically characterized by the secretion of proinflammatory autocrine and paracrine cytokines, potentiation of the interferon (IFN) response, and induction of the antiviral response via activation of JAK and Stat signaling. To avoid these and propagate, viruses have evolved strategies to evade or counteract host sensing. In this study, we demonstrate that murine norovirus controls the antiviral response by activating a metabolic stress response that activates the amino acid response and impairs inflammatory signaling. This highlights novel tools in the viral countermeasures arsenal and demonstrates the importance of the currently poorly understood metabolic reprogramming occurring during viral infections.
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Affiliation(s)
- Michèle Brocard
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Jia Lu
- Division of Virology, Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Belinda Hall
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Khushboo Borah
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Carla Moller-Levet
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Iliana Georgana
- Division of Virology, Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Frederic Sorgeloos
- Division of Virology, Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Dany J. V. Beste
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - Ian G. Goodfellow
- Division of Virology, Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Nicolas Locker
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
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5
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Vilas-Boas EA, Nalbach L, Ampofo E, Lucena CF, Naudet L, Ortis F, Carpinelli AR, Morgan B, Roma LP. Transient NADPH oxidase 2-dependent H 2O 2 production drives early palmitate-induced lipotoxicity in pancreatic islets. Free Radic Biol Med 2021; 162:1-13. [PMID: 33249137 DOI: 10.1016/j.freeradbiomed.2020.11.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 01/12/2023]
Abstract
Modern lifestyles, including lack of physical activity and poor nutritional habits, are driving the rapidly increasing prevalence of obesity and type 2 diabetes. Increased levels of free fatty acids (FFAs), particularly saturated FFAs, in obese individuals have been linked to pancreatic β-cell failure. This process, termed lipotoxicity, involves activation of several stress responses, including ER stress and oxidative stress. However, the molecular underpinnings and causal relationships between the disparate stress responses remain unclear. Here we employed transgenic mice, expressing a genetically-encoded cytosolic H2O2 sensor, roGFP2-Orp1, to monitor dynamic changes in H2O2 levels in pancreatic islets in response to chronic palmitate exposure. We identified a transient increase in H2O2 levels from 4 to 8 h after palmitate addition, which was mirrored by a concomitant decrease in cellular NAD(P)H levels. Intriguingly, islets isolated from NOX2 knock-out mice displayed no H2O2 transient upon chronic palmitate treatment. Furthermore, NOX2 knockout rescued palmitate-dependent impairment of insulin secretion, calcium homeostasis and viability. Chemical inhibition of NOX activity protected islets from palmitate-induced impairment in insulin secretion, however had no detectable impact upon the induction of ER stress. In summary, our results reveal that transient NOX2-dependent H2O2 production is a likely cause of early palmitate-dependent lipotoxic effects.
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Affiliation(s)
- Eloisa Aparecida Vilas-Boas
- Department of Biophysics, Center for Human and Molecular Biology (ZHMB), Saarland University, Homburg, Germany; Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Lisa Nalbach
- Institute for Clinical and Experimental Surgery, Saarland University, Homburg, Germany
| | - Emmanuel Ampofo
- Institute for Clinical and Experimental Surgery, Saarland University, Homburg, Germany
| | - Camila Ferraz Lucena
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Léa Naudet
- Department of Biophysics, Center for Human and Molecular Biology (ZHMB), Saarland University, Homburg, Germany
| | - Fernanda Ortis
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Angelo Rafael Carpinelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil
| | - Bruce Morgan
- Institute for Biochemistry, Center for Human and Molecular Biology (ZHMB), Saarland University, Saarbrücken, Germany
| | - Leticia Prates Roma
- Department of Biophysics, Center for Human and Molecular Biology (ZHMB), Saarland University, Homburg, Germany.
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6
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Lee S, Desai P, Edirisinghe B, Pianello S, Curcio T, Samuel M, Ritchie EK, Roboz GJ. Phase II study of the clinical efficacy and safety of tosedostat in patients with myelodysplastic syndromes (MDS) after failure of hypomethylating agent-based therapy. Leuk Lymphoma 2020; 62:498-500. [PMID: 33043735 DOI: 10.1080/10428194.2020.1832674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Sangmin Lee
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Pinkal Desai
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Bianca Edirisinghe
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Samantha Pianello
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Tania Curcio
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Michael Samuel
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Ellen K Ritchie
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Gail J Roboz
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
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7
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Bartko JC, Li Y, Sun G, Halterman MW. Phosphorylation within the bipartite NLS alters the localization and toxicity of the ER stress response factor DDIT3/CHOP. Cell Signal 2020; 74:109713. [PMID: 32673756 DOI: 10.1016/j.cellsig.2020.109713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/06/2020] [Accepted: 07/09/2020] [Indexed: 02/04/2023]
Abstract
Regulated nuclear-cytoplasmic trafficking is a well-established mechanism utilized by cells to regulate adaptive and maladaptive responses to acute oxidant stress. Commonly associated with endoplasmic reticulum stress, the bZIP transcription factor CCAAT/enhancer-binding protein homologous protein (CHOP/DDIT3) mediates the cellular response to redox stress with effects on cellular growth, differentiation, and survival. We show through functional analyses that CHOP contains a conserved, compound pat4/bipartite nuclear localization signal within the basic DNA-binding domain. Using phylogenetic analyses and mass spectrometry, we now show that Ser107 located within the linker region of the bipartite NLS domain is a substrate for phosphorylation under standard culture conditions. Studies using the S107E phospho-mimic of CHOP indicate that changes in the charge properties at this residue regulate CHOP's nuclear-to-cytoplasmic ratio. And while co-stimulation with the SERCA inhibitor thapsigargin induced injury in cells expressing wild-type CHOP, the S107A point-mutant blocked this response. These findings indicate that phosphorylation within the bipartite NLS exerts regulatory effects on both the subcellular localization and toxic potential of DDIT3/CHOP. Future studies geared towards defining the relevant kinase/phosphatase networks that converge on the phosphorylation-regulated NLS (prNLS) phosphoepitope may provide an opportunity to constrain cellular damage in the context of acute ER stress.
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Affiliation(s)
- Jonathan C Bartko
- Departments of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States
| | - Yinghui Li
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States
| | - George Sun
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States
| | - Marc W Halterman
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States; Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States.
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8
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ATF4-Dependent NRF2 Transcriptional Regulation Promotes Antioxidant Protection during Endoplasmic Reticulum Stress. Cancers (Basel) 2020; 12:cancers12030569. [PMID: 32121537 PMCID: PMC7139862 DOI: 10.3390/cancers12030569] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/24/2020] [Accepted: 02/27/2020] [Indexed: 12/03/2022] Open
Abstract
Endoplasmic reticulum (ER) stress generates reactive oxygen species (ROS) that induce apoptosis if left unabated. To limit oxidative insults, the ER stress PKR-like endoplasmic reticulum Kinase (PERK) has been reported to phosphorylate and activate nuclear factor erythroid 2-related factor 2 (NRF2). Here, we uncover an alternative mechanism for PERK-mediated NRF2 regulation in human cells that does not require direct phosphorylation. We show that the activation of the PERK pathway rapidly stimulates the expression of NRF2 through activating transcription factor 4 (ATF4). In addition, NRF2 activation is late and largely driven by reactive oxygen species (ROS) generated during late protein synthesis recovery, contributing to protecting against cell death. Thus, PERK-mediated NRF2 activation encompasses a PERK-ATF4-dependent control of NRF2 expression that contributes to the NRF2 protective response engaged during ER stress-induced ROS production.
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9
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Identification of ASB7 as ER stress responsive gene through a genome wide in silico screening for genes with ERSE. PLoS One 2018; 13:e0194310. [PMID: 29630609 PMCID: PMC5890977 DOI: 10.1371/journal.pone.0194310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 02/28/2018] [Indexed: 01/10/2023] Open
Abstract
The endoplasmic reticulum (ER) not only performs its basic function of regulating calcium homeostasis, lipid biosynthesis, folding, modifying and transporting proteins but also plays a decisive role in regulating multiple cellular processes ranging from cell growth and differentiation to apoptosis and autophagy. Disturbances in ER homeostasis initiate the unfolded protein response (UPR) implicated in the pathogenesis of many human diseases. Drugging the UPR components for therapeutic interventions has received considerable attention. The purpose of this study is to identify genes that are previously unsuspected to be regulated under ER stress. Because ER stress-inducible gene expression is majorly regulated under ERSE elements, we screened human genome by adopting an in silico approach using ERSE elements (I, II, III) as probes and identified 337 candidate genes. Having knowledge of the importance of E3 ubiquitin ligase in the ERAD machinery; we validated our preliminary search by focusing on one of the hits i.e. ASB7 gene that encodes E3 ubiquitin ligase. In HeLa cells, we found that pharmacological induction of ER stress led to an increase in the expression of ASB7 with simultaneous activation of UPR pathways. Although knockdown of ASB7 expression leads to significant reduction in GRP78 and CHOP mRNA levels, it did not protect cells from ER stress-induced cell death. Also, an up-regulation in the expression of pro-inflammatory genes like TNF-α and IL-1β in ASB7 knockdown cells was observed under ER stress. Collectively, our findings suggest that ASB7 is regulated under ER stress and this study also identifies several other genes that could apparently be regulated under ER stress.
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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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Jang JH, Min KJ, Kim S, Park JW, Kwon TK. RU486 Induces Pro-Apoptotic Endoplasmic Reticulum Stress Through the Induction of CHOP Expression by Enhancing C/EBPδ Expression in Human Renal Carcinoma Caki Cells. J Cell Biochem 2015; 117:361-9. [DOI: 10.1002/jcb.25278] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/07/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Ji Hoon Jang
- Department of Immunology; School of Medicine; Keimyung University; 2800 Dalgubeoldaero; Dalseo-Gu Daegu 704-701 South Korea
| | - Kyoung-jin Min
- Department of Immunology; School of Medicine; Keimyung University; 2800 Dalgubeoldaero; Dalseo-Gu Daegu 704-701 South Korea
| | - Shin Kim
- Department of Immunology; School of Medicine; Keimyung University; 2800 Dalgubeoldaero; Dalseo-Gu Daegu 704-701 South Korea
| | - Jong-Wook Park
- Department of Immunology; School of Medicine; Keimyung University; 2800 Dalgubeoldaero; Dalseo-Gu Daegu 704-701 South Korea
| | - Taeg Kyu Kwon
- Department of Immunology; School of Medicine; Keimyung University; 2800 Dalgubeoldaero; Dalseo-Gu Daegu 704-701 South Korea
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12
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Bobak Y, Kurlishchuk Y, Vynnytska-Myronovska B, Grydzuk O, Shuvayeva G, Redowicz MJ, Kunz-Schughart LA, Stasyk O. Arginine deprivation induces endoplasmic reticulum stress in human solid cancer cells. Int J Biochem Cell Biol 2015; 70:29-38. [PMID: 26546743 DOI: 10.1016/j.biocel.2015.10.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 10/20/2015] [Accepted: 10/30/2015] [Indexed: 12/13/2022]
Abstract
Deprivation for the single amino acid arginine is a rapidly developing metabolic anticancer therapy, which allows growth control in a number of highly malignant tumors. Here we report that one of the responses of human solid cancer cells to arginine starvation is the induction of prolonged endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR). Systematic study of two colorectal carcinoma HCT-116 and HT29, glioblastoma U251 MG and ovarian carcinoma SKOV3 cell lines revealed, however, that the ER stress triggered by the absence of arginine does not result in massive apoptosis despite a profound upregulation of the proapoptotic gene CHOP. Instead, Akt- and MAPK-dependent pathways were activated which may counteract proapoptotic signaling. Treatment with DMSO as a disaggregating agent or with cycloheximide to block protein synthesis reduced ER stress evoked by arginine deprivation. On the other hand, ER stress and apoptosis induction in arginine-starved cells could be critically augmented by the arginine analog of plant origin canavanine, but not by the classic ER stress inducer tunicamycin. Our data suggest that canavanine treatment applied under the lack of arginine may enhance the efficacy of arginine deprivation-based anticancer therapy.
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Affiliation(s)
- Yaroslav Bobak
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Drahomanov Str. 14/16, 79005 Lviv, Ukraine.
| | - Yuliya Kurlishchuk
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Drahomanov Str. 14/16, 79005 Lviv, Ukraine; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Fetscherstr. 74, 01307 Dresden, Germany.
| | - Bozhena Vynnytska-Myronovska
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Drahomanov Str. 14/16, 79005 Lviv, Ukraine; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Fetscherstr. 74, 01307 Dresden, Germany.
| | - Olesia Grydzuk
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Drahomanov Str. 14/16, 79005 Lviv, Ukraine.
| | - Galyna Shuvayeva
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Drahomanov Str. 14/16, 79005 Lviv, Ukraine.
| | - Maria J Redowicz
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteur Str. 3, 02-093 Warsaw, Poland.
| | - Leoni A Kunz-Schughart
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Fetscherstr. 74, 01307 Dresden, Germany; Department of Oncology, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK.
| | - Oleh Stasyk
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Drahomanov Str. 14/16, 79005 Lviv, Ukraine.
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Amino acid deprivation promotes tumor angiogenesis through the GCN2/ATF4 pathway. Neoplasia 2014; 15:989-97. [PMID: 23908598 DOI: 10.1593/neo.13262] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 11/18/2022]
Abstract
As tumors continue to grow and exceed their blood supply, nutrients become limited leading to deficiencies in amino acids (AAD), glucose (GD), and oxygen (hypoxia). These alterations result in significant changes in gene expression. While tumors have been shown to overcome the stress associated with GD or hypoxia by stimulating vascular endothelial growth factor (VEGF)-mediated angiogenesis, the role of AAD in tumor angiogenesis remains to be elucidated. We found that in human tumors, the expression of the general control non-derepressible 2 (GCN2, an AAD sensor) kinase is elevated at both protein and mRNA levels. In vitro studies revealed that VEGF expression is universally induced by AAD treatment in all five cell lines tested (five of five). This is in contrast to two other angiogenesis mediators interleukin-6 (two of five) and fibroblast growth factor 2 (two of five) that have a more restricted expression. Suppressing GCN2 expression significantly decreased AAD-induced VEGF expression. Silencing activating transcription factor 4 (ATF4), a downstream transcription factor of the GCN2 signaling pathway, is also associated with strong inhibition of AAD-induced VEGF expression. PKR-like kinase, the key player in GD-induced unfolded protein response is not involved in this process. In vivo xenograft tumor studies in nonobese diabetic/severe combined immunodeficient mice confirmed that knockdown of GCN2 in tumor cells retards tumor growth and decreases tumor blood vessel density. Our results reveal that the GCN2/ATF4 pathway promotes tumor growth and angiogenesis through AAD-mediated VEGF expression and, thus, is a potential target in cancer therapy.
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DiNardo CD, Cortes JE. Tosedostat for the treatment of relapsed and refractory acute myeloid leukemia. Expert Opin Investig Drugs 2014; 23:265-72. [PMID: 24313331 DOI: 10.1517/13543784.2014.864276] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
INTRODUCTION Despite recent improvements in the scientific understanding of leukemia biology, the overall prognosis for adults with acute myeloid leukemia (AML) remains disappointingly poor. Therapeutic options for AML that are relapsed or refractory to front-line chemotherapy are limited, and the development of effective agents for this indication is an unmet need. The aminopeptidase-inhibitor tosedostat (CHR-2797) is a novel metalloenzyme inhibitor that blocks a critical step in the protein degradation and re-synthesizes intracellular pathway. This orally bioavailable agent has shown promising activity in vitro and in early clinical trials for patients with relapsed/refractory AML. AREAS COVERED This review summarizes the development of tosedostat to date. Specifically, the authors review the literature on its mechanism of action, pharmacoepidemiology and the currently available preclinical and clinical data. EXPERT OPINION Tosedostat is an oral agent with a novel mechanism of action. Early trials of tosedostat in relapsed/refractory elderly AML have shown encouraging results in a population with an overall very poor prognosis. This is particularly noted in patients with a prior history of myelodysplastic syndrome (MDS) and hypomethylating-agent (HMA) use. Additional studies of tosedostat in rationally designed combinations with cytarabine and HMAs in advanced MDS and refractory AML populations are ongoing. Furthermore, the safety and efficacy evaluation is similarly ongoing, and patient selection will be an important consideration in the continued development of this promising compound.
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Affiliation(s)
- Courtney D DiNardo
- University of Texas MD Anderson Cancer Center, Department of Leukemia , 1515 Holcombe Blvd, Unit 0428, Houston, TX 77030 , USA +1 713 794 5783 ; +1 713 745 4612 ;
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Liu H, Zeng Q, Cui Y, Zhao L, Zhang L, Fu G, Hou C, Zhang S, Yu L, Jiang C, Wang Z, Chen X, Wang A. The role of the IRE1 pathway in excessive iodide- and/or fluoride-induced apoptosis in Nthy-ori 3-1 cells in vitro. Toxicol Lett 2013; 224:341-8. [PMID: 24231001 DOI: 10.1016/j.toxlet.2013.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/31/2013] [Accepted: 11/01/2013] [Indexed: 10/26/2022]
Abstract
Excessive iodide and fluoride coexist in the groundwater in many regions, causing a potential risk to the human thyroid. To investigate the mechanism of iodide- and fluoride-induced thyroid cytotoxicity, human thyroid follicular epithelial cells (Nthy-ori 3-1) were treated with different concentrations of potassium iodide (KI), with or without sodium fluoride (NaF). Cell morphology, viability, lactate dehydrogenase (LDH) leakage, apoptosis, and expression of inositol-requiring enzyme 1 (IRE1) pathway-related molecules were assessed. Results showed 50 mM of KI, 1 mM of NaF, and 50 mM of KI +1 mM of NaF changed cellular morphology, decreased viability, and increased LDH leakage and apoptosis. Elevated expression of binding protein (BiP), IRE1, and C/EBP homologous protein (CHOP) mRNA and protein, as well as spliced X-box-binding protein-1 (sXBP-1) mRNA, were observed in the 1 mM NaF and 50 mM KI +1 mM NaF groups. Collectively, excessive iodide and/or fluoride is cytotoxic to the human thyroid. Although these data do not manifest iodide could induce the IRE1 pathway, the cytotoxicity followed by exposure to fluoride alone or in combination with iodide may be related to IRE1 pathway-induced apoptosis. Furthermore, exposure to the combination of excessive iodide and fluoride may cause interactive effects on thyroid cytotoxicity.
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Affiliation(s)
- Hongliang Liu
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China.
| | - Qiang Zeng
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Yushan Cui
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Liang Zhao
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Lei Zhang
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Gang Fu
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Changchun Hou
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Shun Zhang
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China
| | - Linyu Yu
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Chunyang Jiang
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China
| | - Zhenglun Wang
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China
| | - Xuemin Chen
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China
| | - Aiguo Wang
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China.
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Cortes J, Feldman E, Yee K, Rizzieri D, Advani AS, Charman A, Spruyt R, Toal M, Kantarjian H. Two dosing regimens of tosedostat in elderly patients with relapsed or refractory acute myeloid leukaemia (OPAL): a randomised open-label phase 2 study. Lancet Oncol 2013; 14:354-62. [PMID: 23453583 DOI: 10.1016/s1470-2045(13)70037-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Tosedostat is a novel oral aminopeptidase inhibitor with clinical activity in a previous phase 1-2 study in elderly patients with relapsed or refractory acute myeloid leukaemia (AML). We aimed to compare two dosing regimens of tosedostat. METHODS In this randomised phase 2 study, patients aged 60 years or older with AML that had relapsed after a first complete remission lasting less than 12 months, or had achieved no previous complete remission, were randomly assigned (1:1) to receive as first salvage tosedostat 120 mg once daily for 6 months or 240 mg once daily for 2 months followed by 120 mg for 4 months. Randomisation was by block method via an interactive web response system using a randomisation schedule generated by an external vendor, with no stratification. The study was open label. The primary endpoint was the proportion of patients who obtained a complete remission or complete remission with incomplete platelet recovery. Analyses included all patients randomly assigned to treatment groups who received at least one oral dose of tosedostat. The study is registered with ClinicalTrials.gov, number NCT00780598. FINDINGS 38 patients were randomly assigned to receive tosedostat 120 mg and 38 to receive the tosedostat 240 mg to 120 mg regimen. 38 patients in the 120 mg group and 35 in the 240 mg to 120 mg group received tosedostat. Seven patients (10%) had complete remission or complete remission with incomplete platelet recovery: two (5%) in the 120 mg group and five (14%) in the 240 mg to 120 mg group. The most common grade 3 or worse adverse events were febrile neutropenia (11 [29%] patients in the 120 mg group and ten [29%] of the 240 mg to 120 mg group), thrombocytopenia (eight [21%] and eight [23%] patients), fatigue (seven [18%] and eight [23%] patients), dyspnoea (five [13%] and seven [20%] patients), and pneumonia (four [11%] and six [17%] patients). There were five fatal adverse events deemed to be treatment-related: three in the 120 mg group and two in the 240 mg to 120 mg group. The events were acute hepatitis, respiratory failure, pneumonia, atrial fibrillation, and left ventricular dysfunction. INTERPRETATION Tosedostat, at either dose schedule, has activity in older patients with relapsed or refractory AML. Additional studies of tosedostat including combination with hypomethylating agents and low-dose cytarabine in patients with high-risk myelodysplastic syndromes and AML are ongoing or planned. FUNDING Chroma Therapeutics.
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Affiliation(s)
- Jorge Cortes
- Department of Leukemia, Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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Park SH, Moon Y. Integrated stress response-altered pro-inflammatory signals in mucosal immune-related cells. Immunopharmacol Immunotoxicol 2012; 35:205-14. [PMID: 23237490 DOI: 10.3109/08923973.2012.742535] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Various cells are associated with the integrated stress response (ISR) that leads to translation arrest via phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2. Pathogenic insults or nutritional imbalance in the mucosal tissues including the intestinal, airway, and genitourinary epithelia can cause ISRs, which have been linked to different mucosal inflammatory responses and subsequent systemic diseases. In particular, translational arrest caused by the early recognition of luminal microbes as well as nutritional status allows the human body to mount appropriate responses and maintain homeostasis both at the cellular and systemic levels. However, an over- or reduced ISR can create pathogenic conditions such as inflammation and carcinogenesis. This present review explores the association between eIF2α kinase-linked pathways and mucosal or systemic pro-inflammatory signals activated by xenobiotic insults (such as ones caused by microbes or nutritional abnormalities). Understanding ISR-modulated cellular alterations will provide progressive insights into approaches for treating human mucosal inflammatory and metabolic disorders.
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Affiliation(s)
- Seong-Hwan Park
- Laboratory of Mucosal Exposome and Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan, South Korea
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Canh Hiep N, Kinohira S, Furuyama K, Taketani S. Depletion of glutamine enhances sodium butyrate-induced erythroid differentiation of K562 cells. J Biochem 2012; 152:509-19. [DOI: 10.1093/jb/mvs097] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Mohan C, Sathyamurthy M, Lee GM. A role of GADD153 in ER stress-induced apoptosis in recombinant Chinese hamster ovary cells. BIOTECHNOL BIOPROC E 2012. [DOI: 10.1007/s12257-011-0653-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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CK2 regulates ATF4 and CHOP transcription within the cellular stress response signalling pathway. Cell Signal 2012; 24:1797-802. [PMID: 22609407 DOI: 10.1016/j.cellsig.2012.05.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 05/09/2012] [Indexed: 11/22/2022]
Abstract
Protein kinase CK2 is an ubiquitously expressed serine/threonine kinase. The protein levels along with CK2 activity are highly elevated in tumour cells where it protects cells from apoptosis. Accordingly, inhibition of CK2 is known to induce programmed cell death, making it a promising target for cancer therapy. Analysis of the different behaviour of hormone sensitive LNCaP cells and hormone refractory PC-3 cells after CK2 inhibition revealed CHOP ((C/EBP)-homologous protein) induction and therefore probably ER stress as crucial for apoptosis in the LNCaP cells. In the present study we investigated which promoter element of the CHOP promoter is responsible for its induction. ER stress can be generated by the accumulation of unfolded proteins, by depletion of amino acids or by oxidative stress. ER stress induces specific signalling pathways. In order to analyse which pathway might be activated by CK2 inhibition we started to analyse the activation of the different CHOP promoter elements. By using mutated reporter constructs of the CHOP promoter, it turned out that the amino acid response element (AARE) is the most prominent element for CHOP induction after CK2 inhibition. The ER stress element, however, proves to be less crucial, and along with the AP-1 binding site, they do not seem to play any role. Further we found an up-regulation of the transcription factor ATF4 after CK2 inhibition. ATF4 is involved in ER stress signalling through the AARE, which further supports our finding that CK2 inhibition provokes an amino acid induced response pathway.
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Kilberg MS, Balasubramanian M, Fu L, Shan J. The transcription factor network associated with the amino acid response in mammalian cells. Adv Nutr 2012; 3:295-306. [PMID: 22585903 PMCID: PMC3649461 DOI: 10.3945/an.112.001891] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mammals exhibit multiple adaptive mechanisms that sense and respond to fluctuations in dietary nutrients. Consumption of reduced total dietary protein or a protein diet that is deficient in 1 or more of the essential amino acids triggers wide-ranging changes in feeding behavior and gene expression. At the level of individual cells, dietary protein deficiency is manifested as amino acid (AA) deprivation, which activates the AA response (AAR). The AAR is composed of a collection of signal transduction pathways that terminate in specific transcriptional programs designed to catalyze adaptation to the nutrient stress or, ultimately, undergo apoptosis. Independently of the AAR, endoplasmic reticulum stress activates 3 signaling pathways, collectively referred to as the unfolded protein response. The transcription factor activating transcription factor 4 is one of the terminal transcriptional mediators for both the AAR and the unfolded protein response, leading to a significant degree of overlap with regard to the target genes for these stress pathways. Over the past 5 y, research has revealed that the basic leucine zipper superfamily of transcription factors plays the central role in the AAR. Formation of both homo- and heterodimers among the activating transcription factor, CCAAT enhancer-binding protein, and FOS/JUN families of basic leucine zipper proteins forms the nucleus of a highly integrated transcription factor network that determines the initiation, magnitude, and duration of the cellular response to dietary protein or AA limitation.
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22
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Jauhiainen A, Thomsen C, Strömbom L, Grundevik P, Andersson C, Danielsson A, Andersson MK, Nerman O, Rörkvist L, Ståhlberg A, Åman P. Distinct cytoplasmic and nuclear functions of the stress induced protein DDIT3/CHOP/GADD153. PLoS One 2012; 7:e33208. [PMID: 22496745 PMCID: PMC3322118 DOI: 10.1371/journal.pone.0033208] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 02/10/2012] [Indexed: 11/29/2022] Open
Abstract
DDIT3, also known as GADD153 or CHOP, encodes a basic leucine zipper transcription factor of the dimer forming C/EBP family. DDIT3 is known as a key regulator of cellular stress response, but its target genes and functions are not well characterized. Here, we applied a genome wide microarray based expression analysis to identify DDIT3 target genes and functions. By analyzing cells carrying tamoxifen inducible DDIT3 expression constructs we show distinct gene expression profiles for cells with cytoplasmic and nuclear localized DDIT3. Of 175 target genes identified only 3 were regulated by DDIT3 in both cellular localizations. More than two thirds of the genes were downregulated, supporting a role for DDIT3 as a dominant negative factor that could act by either cytoplasmic or nuclear sequestration of dimer forming transcription factor partners. Functional annotation of target genes showed cell migration, proliferation and apoptosis/survival as the most affected categories. Cytoplasmic DDIT3 affected more migration associated genes, while nuclear DDIT3 regulated more cell cycle controlling genes. Cell culture experiments confirmed that cytoplasmic DDIT3 inhibited migration, while nuclear DDIT3 caused a G1 cell cycle arrest. Promoters of target genes showed no common sequence motifs, reflecting that DDIT3 forms heterodimers with several alternative transcription factors that bind to different motifs. We conclude that expression of cytoplasmic DDIT3 regulated 94 genes. Nuclear translocation of DDIT3 regulated 81 additional genes linked to functions already affected by cytoplasmic DDIT3. Characterization of DDIT3 regulated functions helps understanding its role in stress response and involvement in cancer and degenerative disorders.
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Affiliation(s)
- Alexandra Jauhiainen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden
| | - Christer Thomsen
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Linda Strömbom
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Pernilla Grundevik
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Carola Andersson
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Anna Danielsson
- Department of Oncology, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Mattias K. Andersson
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Olle Nerman
- Department of Mathematical Statistics, Chalmers University of Technology, Gothenburg, Sweden
- Department of Mathematical Statistics, University of Gothenburg, Gothenburg, Sweden
| | - Linda Rörkvist
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Anders Ståhlberg
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
| | - Pierre Åman
- Sahlgrenska Cancer Center, Department of Pathology, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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Dalton LE, Healey E, Irving J, Marciniak SJ. Phosphoproteins in stress-induced disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 106:189-221. [PMID: 22340719 DOI: 10.1016/b978-0-12-396456-4.00003-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The integrated stress response (ISR) is an evolutionarily conserved homeostatic program activated by specific pathological states. These include amino acid deprivation, viral infection, iron deficiency, and the misfolding of proteins within the endoplasmic reticulum (ER), the so-called ER stress. Although apparently disparate, each of these stresses induces phosphorylation of a translation initiation factor, eIF2α, to attenuate new protein translation while simultaneously triggering a transcriptional program. This is achieved by four homologous stress-sensing kinases: GCN2, PKR, HRI, and PERK. In addition to these kinases, mammals possess two specific eIF2α phosphatases, GADD34 and CReP, which play crucial roles in the recovery of protein synthesis following the initial insult. They are not only important in embryonic development but also appear to play important roles in disease, particularly cancer. In this chapter, we discuss each of the eIF2α kinases, in turn, with particular emphasis on their regulation and the new insights provided by recent structural studies. We also discuss the potential for developing novel drug therapies that target the ISR.
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Affiliation(s)
- Lucy E Dalton
- Division of Respiratory Medicine, Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom
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Lynes EM, Simmen T. Urban planning of the endoplasmic reticulum (ER): how diverse mechanisms segregate the many functions of the ER. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1893-905. [PMID: 21756943 PMCID: PMC7172674 DOI: 10.1016/j.bbamcr.2011.06.011] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/22/2011] [Accepted: 06/23/2011] [Indexed: 12/21/2022]
Abstract
The endoplasmic reticulum (ER) is the biggest organelle in most cell types, but its characterization as an organelle with a continuous membrane belies the fact that the ER is actually an assembly of several, distinct membrane domains that execute diverse functions. Almost 20 years ago, an essay by Sitia and Meldolesi first listed what was known at the time about domain formation within the ER. In the time that has passed since, additional ER domains have been discovered and characterized. These include the mitochondria-associated membrane (MAM), the ER quality control compartment (ERQC), where ER-associated degradation (ERAD) occurs, and the plasma membrane-associated membrane (PAM). Insight has been gained into the separation of nuclear envelope proteins from the remainder of the ER. Research has also shown that the biogenesis of peroxisomes and lipid droplets occurs on specialized membranes of the ER. Several studies have shown the existence of specific marker proteins found on all these domains and how they are targeted there. Moreover, a first set of cytosolic ER-associated sorting proteins, including phosphofurin acidic cluster sorting protein 2 (PACS-2) and Rab32 have been identified. Intra-ER targeting mechanisms appear to be superimposed onto ER retention mechanisms and rely on transmembrane and cytosolic sequences. The crucial roles of ER domain formation for cell physiology are highlighted with the specific targeting of the tumor metastasis regulator gp78 to ERAD-mediating membranes or of the promyelocytic leukemia protein to the MAM.
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Affiliation(s)
- Emily M Lynes
- Department of Cell Biology, University of Alberta, Alberta, Canada
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Thomas SE, Dalton LE, Daly ML, Malzer E, Marciniak SJ. Diabetes as a disease of endoplasmic reticulum stress. Diabetes Metab Res Rev 2010; 26:611-21. [PMID: 20922715 DOI: 10.1002/dmrr.1132] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 08/17/2010] [Accepted: 09/06/2010] [Indexed: 01/19/2023]
Abstract
Endoplasmic reticulum (ER) stress is an integral part of life for all professional secretory cells, but it has been studied to greatest depth in the pancreatic β-cell. This reflects both the crucial role played by ER stress in the pathogenesis of diabetes and also the exquisite vulnerability of these cells to ER dysfunction. The adaptive cellular response to ER stress, the unfolded protein response, comprises mechanisms to both regulate new protein translation and a transcriptional program to allow adaptation to the stress. The core of this response is a triad of stress-sensing proteins: protein kinase R-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1) and activating transcription factor 6. All three regulate portions of the transcriptional unfolded protein response, while PERK also attenuates protein synthesis during ER stress and IRE1 interacts directly with the c-Jun amino-terminal kinase stress kinase pathway. In this review we shall discuss these processes in detail, with emphasis given to their impact on diabetes and how recent findings indicate that ER stress may be responsible for the loss of β-cell mass in the disease.
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Affiliation(s)
- Sally E Thomas
- Department of Medicine, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, UK
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Reid AH, Protheroe A, Attard G, Hayward N, Vidal L, Spicer J, Shaw HM, Bone EA, Carter J, Hooftman L, Harris A, De Bono JS. A First-in-Man Phase I and Pharmacokinetic Study on CHR-2797 (Tosedostat), an Inhibitor of M1 Aminopeptidases, in Patients with Advanced Solid Tumors. Clin Cancer Res 2009; 15:4978-85. [DOI: 10.1158/1078-0432.ccr-09-0306] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Transcriptional induction of the human asparagine synthetase gene during the unfolded protein response does not require the ATF6 and IRE1/XBP1 arms of the pathway. Biochem J 2009; 417:695-703. [PMID: 18840095 DOI: 10.1042/bj20081706] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The UPR (unfolded protein response) pathway comprises three signalling cascades mediated by the ER (endoplasmic reticulum) stress-sensor proteins PERK [PKR (double-stranded RNA-activated protein kinase)-like ER kinase], IRE1 (inositol-requiring kinase 1) and ATF6 (activating transcription factor 6). The present study shows that ASNS (asparagine synthetase) transcription activity was up-regulated in HepG2 cells treated with the UPR activators thapsigargin and tunicamycin. ChIP (chromatin immunoprecipitation) analysis demonstrated that during ER stress, ATF4, ATF3 and C/EBPbeta (CCAAT/enhancer-binding protein beta) bind to the ASNS proximal promoter region that includes the genomic sequences NSRE (nutrient-sensing response element)-1 and NSRE-2, previously implicated by mutagenesis in UPR activation. Consistent with increased ASNS transcription, ChIP analysis also demonstrated that UPR signalling resulted in enhanced recruitment of general transcription factors, including RNA Pol II (polymerase II), to the ASNS promoter. The ASNS gene is also activated by the AAR (amino acid response) pathway following amino acid deprivation of tissue or cells. Immunoblot analysis of HepG2 cells demonstrated that simultaneous activation of the AAR and UPR pathways did not further increase the ASNS or ATF4 protein abundance when compared with triggering either pathway alone. In addition, siRNA (small interfering RNA)-mediated knockdown of XBP1 (X-box-binding protein 1), ATF6alpha or ATF6beta expression did not affect ASNS transcription, whereas siRNA against ATF4 suppressed ASNS transcription during UPR activation. Collectively, these results indicate that the PERK/p-eIF2alpha (phosphorylated eukaryotic initiation factor 2alpha)/ATF4 signalling cascade is the only arm of the UPR that is responsible for ASNS transcriptional induction during ER stress. Consequently, ASNS NSRE-1 and NSRE-2, in addition to ERSE (ER stress response element)-I, ERSE-II and the mUPRE (mammalian UPR element), function as mammalian ER-stress-responsive sequences.
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Wang Z, Chen H. Amino acid limitation induces down-regulation of WNT5a at transcriptional level. Biochem Biophys Res Commun 2008; 378:789-94. [PMID: 19063862 DOI: 10.1016/j.bbrc.2008.11.124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Accepted: 11/22/2008] [Indexed: 10/21/2022]
Abstract
An aberrant WNT signaling contributes to the development and progression of multiple cancers. WNT5a is one of the WNT signaling molecules. This study was designed to test the hypothesis that amino acid deprivation induces changes in the WNT signaling pathway in colon cancer cells. Results showed that targets of the amino acid response pathway, ATF3 and p21, were induced in the human colon cancer cell line SW480 during amino acid limitation. There was a significant decrease in the WNT5a mRNA level following amino acid deprivation. The down-regulation of WNT5a mRNA by amino acid deprivation is not due to mRNA destabilization. There is a reduction of nuclear beta-catenin protein level by amino acid limitation. Under amino acid limitation, phosphorylation of ERK1/2 was increased and the blockage of ERK1/2 by the inhibitor U0126 partially restored WNT5a mRNA level. In conclusion, amino acid limitation in colon cancer cells induces phosphorylation of ERK1/2, which then down-regulates WNT5a expression.
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Affiliation(s)
- Zuguang Wang
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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29
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Gjymishka A, Palii SS, Shan J, Kilberg MS. Despite increased ATF4 binding at the C/EBP-ATF composite site following activation of the unfolded protein response, system A transporter 2 (SNAT2) transcription activity is repressed in HepG2 cells. J Biol Chem 2008; 283:27736-27747. [PMID: 18697751 PMCID: PMC2562058 DOI: 10.1074/jbc.m803781200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 07/16/2008] [Indexed: 12/20/2022] Open
Abstract
The activated amino acid response (AAR) and unfolded protein response (UPR) stress signaling pathways converge at the phosphorylation of translation initiation factor eIF2alpha. This eIF2alpha modification suppresses global protein synthesis but enhances translation of selected mRNAs such as that for activating transcription factor 4 (ATF4). An ATF4 target gene, SNAT2 (system A sodium-dependent neutral amino acid transporter 2), contains a C/EBP-ATF site that binds ATF4 and triggers increased transcription during the AAR. However, the present studies show that despite increased ATF4 binding to the SNAT2 gene during UPR activation in HepG2 human hepatoma cells, transcription activity was not enhanced. Hyperacetylation of histone H3 and recruitment of the general transcription factors at the HepG2 SNAT2 promoter occurred in response to the AAR but not the UPR. In contrast, the UPR did enhance transcription from a plasmid-based reporter gene driven by a SNAT2 genomic fragment containing the C/EBP-ATF site. Simultaneous activation of the AAR and the UPR pathways revealed that the UPR actually suppressed the increased SNAT2 transcription by the AAR pathway, demonstrating that the UPR pathway generates a repressive signal that acts downstream of ATF4 binding.
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Affiliation(s)
- Altin Gjymishka
- Department of Biochemistry and Molecular Biology, Genetics Institute, Shands Cancer Center and Center for Nutritional Sciences, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Stela S Palii
- Department of Biochemistry and Molecular Biology, Genetics Institute, Shands Cancer Center and Center for Nutritional Sciences, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Jixiu Shan
- Department of Biochemistry and Molecular Biology, Genetics Institute, Shands Cancer Center and Center for Nutritional Sciences, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Michael S Kilberg
- Department of Biochemistry and Molecular Biology, Genetics Institute, Shands Cancer Center and Center for Nutritional Sciences, University of Florida College of Medicine, Gainesville, Florida 32610.
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30
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Nagata T, Ilieva H, Murakami T, Shiote M, Narai H, Ohta Y, Hayashi T, Shoji M, Abe K. Increased ER stress during motor neuron degeneration in a transgenic mouse model of amyotrophic lateral sclerosis. Neurol Res 2008; 29:767-71. [PMID: 17672929 DOI: 10.1179/016164107x229803] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The endoplasmic reticulum (ER), which plays important roles in apoptosis, is susceptible to oxidative stress. ER stress is also thought to be involved in the pathogenesis of neurodegenerative diseases. In this study, we investigated whether ER stress is involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) using the anterior part of the lumbar spinal cord of transgenic mice carrying a mutation (G93A) in the superoxide dismutase 1 (SOD1) gene. Western blot and immunohistochemical analyses demonstrated that the expressions of p-PERK and p-eIF2alpha were increased in the microsome fraction (P3) of the lumbar spinal cord at the pre-symptomatic age of 12 weeks (12W), while the expression of activated caspase-12 was increased in the cytoplasmic fraction (S3) of the lumbar spinal cord at both the pre-symptomatic age of 12W and the late symptomatic age of 20W. In contrast, GRP78 did not show any increases in the microsome fraction (P3) of the lumbar spinal cord at either the pre-symptomatic or symptomatic ages. Thus, the present results strongly suggest that the balance between anti- and pro-apoptotic proteins related to ER stress is impaired from the pre-symptomatic stage in this ALS mouse model, and that this imbalance may be related to the pathogenesis of motor neuron degeneration in ALS.
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Affiliation(s)
- Tetsuya Nagata
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan.
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31
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Gragnoli C, Pierpaoli L, Piumelli N, Chiaramonte F. Linkage studies for T2D in Chop and C/EBPbeta chromosomal regions in Italians. J Cell Physiol 2008; 213:552-5. [PMID: 17620318 DOI: 10.1002/jcp.21132] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The genes causing type 2 diabetes (T2D), a complex heterogeneous disorder, differ and/or overlap in various populations. Among others there are two loci in linkage to T2D, the chromosomes 20q12-13.1 and 12q15. These two regions harbor two genes, C/EBPbeta and CHOP, which are excellent candidate genes for T2D. In fact, C/EBPbeta protein cooperates with HNF4alpha (MODY1, monogenic form of diabetes) and 1alpha (MODY3, monogenic form of diabetes). C/EBPbeta mediates suppression of insulin gene transcription in hyperglycemia and may contribute to insulin-resistance. It interacts in a complex pathway with the CHOP protein. CHOP may play a role in altered beta-cell glucose metabolism, in beta-cell apoptosis, and in lack of beta-cell replication. Thus, both C/EBPbeta and CHOP genes may independently and interactively contribute to T2D. The chromosomal regions targeting C/EBPbeta and CHOP genes have never been previously explored in T2D. We planned to identify their potential contribution to T2D in Italians. We have genotyped a group of affected siblings/families with both late- and early-onset T2D around the C/EBPbeta and the CHOP genes. We have performed non-parametric linkage analysis in the total T2D group, in the late-onset and the early-onset group, separately. We have identified a suggestive linkage to T2D in the CHOP gene locus in the early-onset T2D group (P = 0.04). We identified the linkage to T2D in the chromosome 12q15 region in the early-onset T2D families and specifically target the CHOP gene. Our next step will be the identification of CHOP gene variants, which may contribute to the linkage to T2D in Italians.
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Affiliation(s)
- Claudia Gragnoli
- Laboratory of Molecular Genetics of Monogenic and Complex Disorders, Endocrinology, Diabetes & Metabolism, Medicine and Cellular & Molecular Physiology, Milton S. Hershey Medical Center, Hershey, Pennsylvania 17033, USA.
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32
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Drogat B, Bouchecareilh M, North S, Petibois C, Déléris G, Chevet E, Bikfalvi A, Moenner M. Acute L-glutamine deprivation compromises VEGF-a upregulation in A549/8 human carcinoma cells. J Cell Physiol 2007; 212:463-72. [PMID: 17348020 DOI: 10.1002/jcp.21044] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tumor ischemia participates in angiogenesis and cancer progression through cellular responses to hypoxia and nutrient deprivation. However, the contribution of amino acids limitation to this process remains poorly understood. Using serum-free cell culture conditions, we tested the impact of L-glutamine deprivation on metabolic and angiogenic responses in A549/8 carcinoma cells. In these cells, lowering glutamine concentration modified the cell cycle distribution and significantly induced apoptosis/necrosis. Although glutamine deprivation led to a HIF-independent increase in VEGF-A mRNA, the corresponding protein level remained low and correlated with the inhibition of protein synthesis and activation of the GCN2/eIF2alpha pathway. Limitation of glutamine availability also hampers hypoxia- and hypoglycemia-induced VEGF-A protein upregulation. Thus, glutamine deprivation may have no direct effect on VEGF-dependent angiogenesis, compared to hypoxia or to glucose deprivation, and may instead be detrimental to cancer progression by antagonizing ischemia-induced stresses.
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33
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Jackson AA, Cronin KR, Zachariah R, Carew JA. CCAAT/enhancer-binding protein-beta participates in insulin-responsive expression of the factor VII gene. J Biol Chem 2007; 282:31156-65. [PMID: 17675296 DOI: 10.1074/jbc.m704694200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Expression of the human coagulation factor VII (FVII) gene by hepatoma cells was modulated in concert with levels of glucose and insulin in the culture medium. In low glucose medium without insulin, amounts of both FVII mRNA and secreted FVII protein were coordinately increased; in the presence of glucose with insulin, both were decreased. Analysis of the FVII promoter showed that these effects could be reproduced in a reporter-gene system, and a small promoter element immediately upstream of the translation start site of the gene, which mediated these effects, was identified. Mutation of this element largely abrogated the glucose/insulin-responsive change in expression of the reporter gene. Several members of the CCAAT/enhancer-binding protein family were found to be capable of binding the identified sequence element but not the mutated element. The expression of a FVII minigene directed by a segment of the native FVII promoter responded to co-expressed activating and inhibiting forms of CCAAT/enhancer-binding protein beta.
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Affiliation(s)
- Audrey A Jackson
- Veterans Affairs Boston Healthcare System, West Roxbury, Massachusetts 02132, USA
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34
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Anding AL, Chapman JS, Barnett DW, Curley RW, Clagett-Dame M. The unhydrolyzable fenretinide analogue 4-hydroxybenzylretinone induces the proapoptotic genes GADD153 (CHOP) and Bcl-2-binding component 3 (PUMA) and apoptosis that is caspase- dependent and independent of the retinoic acid receptor. Cancer Res 2007; 67:6270-7. [PMID: 17616685 DOI: 10.1158/0008-5472.can-07-0727] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The synthetic retinoid N-(4-hydroxyphenyl)retinamide (4-HPR) induces apoptosis in a variety of cell lines and has shown promise as an anticancer agent both in vitro and in vivo. The clinical dose of 4-HPR, however, is limited by residual-associated toxicities, indicating a need for a less toxic drug. In this study, we show that 4-hydroxybenzylretinone (4-HBR), the unhydrolyzable analogue of 4-HPR, is effective in producing apoptosis in a variety of 4-HPR-sensitive cell lines, including breast cancer, neuroblastoma, and leukemia cells. We also show through the use of a pan-caspase inhibitor that this 4-HBR-induced apoptosis is dependent, at least in part, on caspase activity. 4-HBR is shown to exhibit binding to the retinoic acid receptors (RAR) at concentrations necessary to induce cell death and induces expression of all-trans-retinoic acid-responsive genes that can be blocked by a RAR pan-antagonist. However, through the use of this RAR pan-antagonist, 4-HBR-induced apoptosis and cell death is shown to be independent of the RAR signaling pathway. To further characterize the mechanism of action of 4-HBR, expression of the endoplasmic reticulum stress-induced genes GADD153 and Bcl-2-binding component 3 was examined. These mRNAs are shown to be rapidly induced in 4-HBR-treated and 4-HPR-treated breast cancer cells, and this up-regulation is also shown to be independent of the RARs. These results suggest that a stress-mediated apoptotic cascade is involved in the mechanism of action of these retinoids.
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Affiliation(s)
- Allyson L Anding
- Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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35
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Löhrke B, Saggau E, Schadereit R, Beyer M, Bellmann O, Kuhla S, Hagemeister H. Activation of skeletal muscle protein breakdown following consumption of soyabean protein in pigs. Br J Nutr 2007; 85:447-57. [PMID: 11348559 DOI: 10.1079/bjn2000291] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Diets with protein of inferior quality may increase protein breakdown in skeletal muscle but the experimental results are inconsistent. To elucidate the relationship, pigs were fed isoenergetic and isonitrogenous diets based on soyabean-protein isolate or casein for 15 weeks, with four to six animals per group. A higher plasma level of urea (2.5-fold the casein group value, P=0.01), higher urinary N excretion (2.1-fold the casein group value, P=0.01), a postabsorptive rise in the plasma levels of urea, 3-methylhistidine and isoleucine in soyabean protein-fed pigs suggested recruitment of circulatory amino acids by protein breakdown in peripheral tissues. Significant differences between dietary groups were detected in lysosomal and ATP-dependent proteolytic activities in the semimembranosus muscle of food-deprived pigs. A higher concentration of cathepsin B protein was found, corresponding to a rise in the cathepsin B activity, in response to dietary soyabean protein. Muscle ATP-stimulated proteolytical activity was 1.6-fold the casein group value (P=0.03). A transient rise in the level of cortisol (2.9-times the casein group value, P=0.02) occurred in the postprandial phase only in the soyabean group. These data suggest that the inferior quality of dietary soyabean protein induces hormonally-mediated upregulation of muscle protein breakdown for recruitment of circulatory amino acids in a postabsorptive state.
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Affiliation(s)
- B Löhrke
- Research Institute for Biology of Farm Animals, Dummerstorf-Rostock, Department of Animal Nutrition, Germany.
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36
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Kumagai K, Ando Y, Kiyosawa N, Ito K, Kawai R, Yamoto T, Manabe S, Teranishi M. Toxicoproteomic investigation of the molecular mechanisms of cycloheximide-induced hepatocellular apoptosis in rat liver. Toxicology 2006; 228:299-309. [DOI: 10.1016/j.tox.2006.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Revised: 09/23/2006] [Accepted: 09/26/2006] [Indexed: 11/24/2022]
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37
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Watatani Y, Kimura N, Shimizu YI, Akiyama I, Tonaki D, Hirose H, Takahashi S, Takahashi Y. Amino acid limitation induces expression of ATF5 mRNA at the post-transcriptional level. Life Sci 2006; 80:879-85. [PMID: 17140605 DOI: 10.1016/j.lfs.2006.11.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 10/23/2006] [Accepted: 11/07/2006] [Indexed: 01/21/2023]
Abstract
ATF5 is a transcription factor in the cAMP response element (CRE)-binding protein/activating transcription factor (CREB/ATF) family. We studied the effect of amino acid limitation on ATF5 mRNA levels in a mammalian cell line. Northern-blot analysis demonstrated that limitation of a single amino acid, glutamine, methionine, or leucine, resulted in increased ATF5 mRNA levels in HeLaS3 cells. This resulted, at least in part, from increased half-life of the ATF5 mRNA transcript. Cycloheximide inhibited the increase in ATF5 mRNA expression induced by glutamine limitation, indicating that it was dependent on de novo protein synthesis. Moreover, rapamycin had no effect on basal ATF5 mRNA expression or on increased expression induced by glutamine limitation. These results indicate that amino acid limitation regulates ATF5 mRNA expression during post-transcription in a rapamycin-independent manner. The potential role for ATF5 in protecting cells from amino acid-limitation is of considerable interest.
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Affiliation(s)
- Yujiro Watatani
- Laboratory of Environmental Molecular Physiology, School of Life Science, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
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38
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Reinert RB, Oberle LM, Wek SA, Bunpo P, Wang XP, Mileva I, Goodwin LO, Aldrich CJ, Durden DL, McNurlan MA, Wek RC, Anthony TG. Role of Glutamine Depletion in Directing Tissue-specific Nutrient Stress Responses to L-Asparaginase. J Biol Chem 2006. [DOI: 10.1016/s0021-9258(19)84035-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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39
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Reinert RB, Oberle LM, Wek SA, Bunpo P, Wang XP, Mileva I, Goodwin LO, Aldrich CJ, Durden DL, McNurlan MA, Wek RC, Anthony TG. Role of glutamine depletion in directing tissue-specific nutrient stress responses to L-asparaginase. J Biol Chem 2006; 281:31222-33. [PMID: 16931516 DOI: 10.1074/jbc.m604511200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
L-asparaginase is important in the induction regimen for treating acute lymphoblastic leukemia. Cytotoxic complications are clinically significant problems lacking mechanistic insight. To reveal tissue-specific molecular responses to this drug, mice were administered asparaginase from either Escherichia coli (clinically used) or Wolinella succinogenes (novel, glutaminase-free form). Both enzymes abolished serum asparagine, but only the E. coli form reduced circulating glutamine. E. coli asparaginase reduced protein synthesis in liver and spleen but not pancreas via increased phosphorylation of the translation factor eIF2. In contrast, treatment with Wolinella caused no untoward changes in protein synthesis in any tissue examined. Treating mice deleted for the eIF2 kinase, GCN2, with the E. coli enzyme showed eIF2 phosphorylation to be GCN2-dependent, but only initially. Furthermore, although eIF2 phosphorylation was not increased in the pancreas or by Wolinella asparaginase, expression of the amino acid stress response genes, asparagine synthetase and CHOP/GADD153, increased as a result of both enzymes, even in tissues demonstrating no change in eIF2 phosphorylation. Finally, signaling downstream of the mammalian target of rapamycin kinase was repressed in liver and pancreas by E. coli but not Wolinella asparaginase. These data demonstrate that the nutrient stress response to asparaginase is tissue-specific and exacerbated by glutamine depletion. Importantly, increased expression of asparagine synthetase and CHOP does not require eIF2 phosphorylation, signifying alternate or auxiliary means of inducing gene expression under conditions of amino acid depletion in the whole animal.
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Affiliation(s)
- Rachel B Reinert
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Evansville, Indiana 47712, USA
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40
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Kilberg MS, Pan YX, Chen H, Leung-Pineda V. Nutritional control of gene expression: how mammalian cells respond to amino acid limitation. Annu Rev Nutr 2005; 25:59-85. [PMID: 16011459 PMCID: PMC3600373 DOI: 10.1146/annurev.nutr.24.012003.132145] [Citation(s) in RCA: 206] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The amino acid response (AAR) pathway in mammalian cells is designed to detect and respond to amino acid deficiency. Limiting any essential amino acid initiates this signaling cascade, which leads to increased translation of a "master regulator," activating transcription factor (ATF) 4, and ultimately, to regulation of many steps along the pathway of DNA to RNA to protein. These regulated events include chromatin remodeling, RNA splicing, nuclear RNA export, mRNA stabilization, and translational control. Proteins that are increased in their expression as targets of the AAR pathway include membrane transporters, transcription factors from the basic region/leucine zipper (bZIP) superfamily, growth factors, and metabolic enzymes. Significant progress has been achieved in understanding the molecular mechanisms by which amino acids control the synthesis and turnover of mRNA and protein. Beyond gaining additional knowledge of these important regulatory pathways, further characterization of how these processes contribute to the pathology of various disease states represents an interesting aspect of future research in molecular nutrition.
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Affiliation(s)
- M S Kilberg
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida 32610-0245, USA.
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41
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Silva RM, Ries V, Oo TF, Yarygina O, Jackson-Lewis V, Ryu EJ, Lu PD, Marciniak SJ, Ron D, Przedborski S, Kholodilov N, Greene LA, Burke RE. CHOP/GADD153 is a mediator of apoptotic death in substantia nigra dopamine neurons in an in vivo neurotoxin model of parkinsonism. J Neurochem 2005; 95:974-86. [PMID: 16135078 PMCID: PMC3082498 DOI: 10.1111/j.1471-4159.2005.03428.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
There is increasing evidence that neuron death in neurodegenerative diseases, such as Parkinson's disease, is due to the activation of programmed cell death. However, the upstream mediators of cell death remain largely unknown. One approach to the identification of upstream mediators is to perform gene expression analysis in disease models. Such analyses, performed in tissue culture models induced by neurotoxins, have identified up-regulation of CHOP/GADD153, a transcription factor implicated in apoptosis due to endoplasmic reticulum stress or oxidative injury. To evaluate the disease-related significance of these findings, we have examined the expression of CHOP/GADD153 in neurotoxin models of parkinsonism in living animals. Nuclear expression of CHOP protein is observed in developmental and adult models of dopamine neuron death induced by intrastriatal injection of 6-hydroxydopamine (6OHDA) and in models induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). CHOP is a mediator of neuron death in the adult 60HDA model because a null mutation results in a reduction in apoptosis. In the chronic MPTP model, however, while CHOP is robustly expressed, the null mutation does not protect from the loss of neurons. We conclude that the role of CHOP depends on the nature of the toxic stimulus. For 6OHDA, an oxidative metabolite of dopamine, it is a mediator of apoptotic death.
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MESH Headings
- 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/adverse effects
- Animals
- Animals, Newborn
- Apoptosis/drug effects
- Apoptosis/physiology
- Axotomy/methods
- Behavior, Animal
- Blotting, Northern/methods
- Blotting, Western/methods
- Cell Count/methods
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Disease Models, Animal
- Dopamine/metabolism
- Female
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Immunohistochemistry/methods
- In Situ Hybridization/methods
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mutation/physiology
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Neurotoxins
- Oxidopamine/toxicity
- Parkinsonian Disorders/etiology
- Parkinsonian Disorders/metabolism
- Parkinsonian Disorders/pathology
- Pregnancy
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Regulatory Factor X Transcription Factors
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Substantia Nigra/growth & development
- Substantia Nigra/pathology
- Time Factors
- Transcription Factor CHOP/deficiency
- Transcription Factor CHOP/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Tyrosine 3-Monooxygenase/metabolism
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Affiliation(s)
- Robert M Silva
- Department of Neurology, The College of Physicians and Surgeons, Columbia University, New York 10032, USA.
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42
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Kubota K, Lee DH, Tsuchiya M, Young CS, Everett ET, Martinez-Mier EA, Snead ML, Nguyen L, Urano F, Bartlett JD. Fluoride induces endoplasmic reticulum stress in ameloblasts responsible for dental enamel formation. J Biol Chem 2005; 280:23194-202. [PMID: 15849362 DOI: 10.1074/jbc.m503288200] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanism of how fluoride causes fluorosis remains unknown. Exposure to fluoride can inhibit protein synthesis, and this may also occur by agents that cause endoplasmic reticulum (ER) stress. When translated proteins fail to fold properly or become misfolded, ER stress response genes are induced that together comprise the unfolded protein response. Because ameloblasts are responsible for dental enamel formation, we used an ameloblast-derived cell line (LS8) to characterize specific responses to fluoride treatment. LS8 cells were growth-inhibited by as little as 1.9-3.8 ppm fluoride, whereas higher doses induced ER stress and caspase-mediated DNA fragmentation. Growth arrest and DNA damage-inducible proteins (GADD153/CHOP, GADD45alpha), binding protein (BiP/glucose-responsive protein 78 (GRP78), the non-secreted form of carbonic anhydrase VI (CA-VI), and active X-box-binding protein-1 (Xbp-1) were all induced significantly after exposure to 38 ppm fluoride. Unexpectedly, DNA fragmentation increased when GADD153 expression was inhibited by short interfering RNA treatment but remained unaffected by transient GADD153 overexpression. Analysis of control and GADD153(-/-) embryonic fibroblasts demonstrated that caspase-3 mediated the increased DNA fragmentation observed in the GADD153 null cells. We also demonstrate that mouse incisor ameloblasts are sensitive to the toxic effects of high dose fluoride in drinking water. Activated Ire1 initiates an ER stress response pathway, and mouse ameloblasts were shown to express activated Ire1. Ire1 levels appeared induced by fluoride treatment, indicating that ER stress may play a role in dental fluorosis. Low dose fluoride, such as that present in fluoridated drinking water, did not induce ER stress.
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Affiliation(s)
- Kaori Kubota
- Department of Cytokine Biology, Forsyth Institute, Harvard School of Dental Medicine, Boston, Massachusetts 02115, USA
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43
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Hayashi T, Saito A, Okuno S, Ferrand-Drake M, Dodd RL, Chan PH. Damage to the endoplasmic reticulum and activation of apoptotic machinery by oxidative stress in ischemic neurons. J Cereb Blood Flow Metab 2005; 25:41-53. [PMID: 15678111 DOI: 10.1038/sj.jcbfm.9600005] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The endoplasmic reticulum (ER), which plays a role in apoptosis, is susceptible to oxidative stress. Because superoxide is produced in the brain after ischemia/reperfusion, oxidative injury to this organelle may be implicated in ischemic neuronal cell death. Activating transcription factor-4 (ATF-4) and C/EBP-homologous protein (CHOP), both of which are involved in apoptosis, are induced by severe ER stress. Using wild-type and human copper/zinc superoxide dismutase transgenic rats, we observed induction of these molecules in the brain after global cerebral ischemia and compared them with neuronal degeneration. In ischemic, wild-type brains, expression of ATF-4 and CHOP was increased in the hippocampal CA1 neurons that would later undergo apoptosis. Transgenic rats had a mild increase in ATF-4 and CHOP and minimal neuronal degeneration, indicating that superoxide was involved in ER stress-induced cell death. We further confirmed attenuation on induction of these molecules in transgenic mouse brains after focal ischemia. When superoxide was visualized with ethidium, signals for ATF-4 and superoxide overlapped in the same cells. Moreover, lipids in the ER were robustly peroxidized by ischemia but were attenuated in transgenic animals. This indicates that superoxide attacked and damaged the ER, and that oxidative ER damage is implicated in ischemic neuronal cell death.
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Affiliation(s)
- Takeshi Hayashi
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94305-5487, USA
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van der Sanden MHM, Meems H, Houweling M, Helms JB, Vaandrager AB. Induction of CCAAT/Enhancer-binding Protein (C/EBP)-homologous Protein/Growth Arrest and DNA Damage-inducible Protein 153 Expression during Inhibition of Phosphatidylcholine Synthesis Is Mediated via Activation of a C/EBP-activating Transcription Factor-responsive Element. J Biol Chem 2004; 279:52007-15. [PMID: 15466475 DOI: 10.1074/jbc.m405577200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gene for the proapoptotic transcription factor CCAAT/enhancer-binding protein (C/EBP)-homologous protein/growth arrest and DNA damage-inducible protein 153 (CHOP/GADD153) is induced by various cellular stresses. Previously, we described that inhibition of phosphatidylcholine (PC) synthesis in MT58 cells, which contain a temperature-sensitive mutation in CTP:phosphocholine cytidylyltransferase (CT), results in apoptosis preceded by the induction of CHOP. Here we report that prevention of CHOP induction, by expression of antisense CHOP, delays the PC depletion-induced apoptotic process. By mutational analysis of the conserved region in the promoter of the CHOP gene, we provide evidence that the C/EBP-ATF composite site, but not the ER stress-responsive element or the activator protein-1 site, is required for the increased expression of CHOP during PC depletion. Inhibition of PC synthesis in MT58 cells also led to an increase in phosphorylation of the stress-related transcription factor ATF2 and the stress kinase JNK after 8 and 16 h, respectively. In contrast, no phosphorylation of p38 MAPK was observed in MT58 cultured at the nonpermissive temperature. Treatment of MT58 cells with the JNK inhibitor SP600125 could rescue the cells from apoptosis but did not inhibit the phosphorylation of ATF2 or the induction of CHOP. Taken together, our results suggest that increased expression of CHOP during PC depletion depends on a C/EBP-ATF element in its promoter and might be mediated by binding of ATF2 to this element.
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Affiliation(s)
- Michiel H M van der Sanden
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, and Institute of Biomembranes, University of Utrecht, PO Box 80176, Utrecht 3508 TD, The Netherlands
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Marutani T, Yamamoto A, Nagai N, Kubota H, Nagata K. Accumulation of type IV collagen in dilated ER leads to apoptosis in Hsp47-knockout mouse embryos via induction of CHOP. J Cell Sci 2004; 117:5913-22. [PMID: 15522896 DOI: 10.1242/jcs.01514] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Hsp47 is an endoplasmic reticulum (ER)-resident molecular chaperone that is specific for collagen. In Hsp47(-/-) mouse embryos at 9.5 days postcoitus (dpc), immunostaining indicated the absence of type IV collagen, but not of laminin and nidogen-1, in the basement membrane (BM). Electron immunomicroscopy revealed accumulation of type IV collagen in dilated ERs, but not in the BM of Hsp47(-/-) embryos, whereas it was only present in the BM in Hsp47(+/+) embryos. The BM structures stained with anti-laminin and anti-nidogen-1 antibody became disrupted in Hsp47(-/-) embryos at 10.5 dpc. Thus, in the absence of type IV collagen in the BM owing to the lack of Hsp47, the structure of the BM cannot be maintained during the dramatic morphological changes that take place around 10.5 dpc. Type IV collagen is therefore indispensable for the maintenance of BM structures during the late-stage development of mouse embryos, although not essential for the initial formation of the BM. Just before the death of Hsp47(-/-) embryos, DNA fragmentation typical of apoptosis was observed at 10.5 dpc together with significantly upregulated CHOP mRNA expression. ER stress caused by the accumulation of misfolded collagen may have induced apoptosis in Hsp47-knockout embryos through the upregulation of CHOP.
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Affiliation(s)
- Toshihiro Marutani
- Department of Molecular and Cellular Biology and CREST/JST, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8397, Japan
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Dimcheff DE, Faasse MA, McAtee FJ, Portis JL. Endoplasmic reticulum (ER) stress induced by a neurovirulent mouse retrovirus is associated with prolonged BiP binding and retention of a viral protein in the ER. J Biol Chem 2004; 279:33782-90. [PMID: 15178688 DOI: 10.1074/jbc.m403304200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Some murine retroviruses cause a spongiform neurodegenerative disease exhibiting pathology resembling that observed in transmissible spongiform encephalopathies. The neurovirulence of these "spongiogenic retroviruses" is determined by the sequence of their respective envelope proteins, although the mechanisms of neurotoxicity are not understood. We have studied a highly neurovirulent virus called FrCasE that causes a rapidly progressive form of this disease. Recently, transcriptional markers of endoplasmic reticulum (ER) stress were detected during the early preclinical period in the brains of FrCasE-infected mice. In contrast, ER stress was not observed in mice infected with an avirulent virus, F43, which carries a different envelope gene, suggesting a role for ER stress in disease pathogenesis. Here we have examined in NIH 3T3 cells the cause of this cellular stress response. The envelope protein of F43 bound BiP, a major ER chaperone, transiently and was processed normally through the secretory pathway. In contrast, the envelope protein of FrCasE bound to BiP for a prolonged period, was retained in the ER, and was degraded by the proteasome. Furthermore, engagement of the FrCasE envelope protein by ER quality control pathways resulted in decreased steady-state levels of this protein, relative to that of F43, both in NIH 3T3 cells and in the brains of infected mice. Thus, the ER stress induced by FrCasE appears to be initiated by inefficient folding of its viral envelope protein, suggesting that the neurodegenerative disease caused by this virus represents a protein misfolding disorder.
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Affiliation(s)
- Derek E Dimcheff
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, National Institutes of Health, Hamilton, Montana 59840, USA
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Ma Y, Hendershot LM. Herp Is Dually Regulated by Both the Endoplasmic Reticulum Stress-specific Branch of the Unfolded Protein Response and a Branch That Is Shared with Other Cellular Stress Pathways. J Biol Chem 2004; 279:13792-9. [PMID: 14742429 DOI: 10.1074/jbc.m313724200] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The mammalian unfolded protein response (UPR) includes two major branches: one(s) specific to ER stress (Ire1/XBP-1 and ATF6-dependent), and one(s) shared by other cellular stresses (PERK/eIF-2alpha phosphorylation-dependent). Here, we demonstrate that the ER-localized protein Herp represents a second target, in addition to CHOP, that is dually regulated by both the shared and the ER stress-specific branches during UPR activation. For the first time, we are able to assess the contribution of each branch of the UPR in the induction of these targets. We demonstrate that activation of the shared branch of the UPR alone was sufficient to induce Herp and CHOP. ATF4 was not required during ER stress when both branches were used but did contribute significantly to their induction. Conversely, stresses that activated only the shared branch of the UPR were completely dependent on ATF4 for CHOP and Herp induction. Thus, the shared and the ER stress-specific branches of the UPR diverge to regulate two groups of targets, one that is ATF6 and Ire1/XBP-1-dependent, which includes BiP and XBP-1, and another that is eIF-2alpha kinase-dependent, which includes ATF4 and GADD34. The two branches also converge to maximally up-regulate targets like Herp and CHOP. Finally, our studies reveal that a PERK-dependent target other than ATF4 is contributing to the cross-talk between the two branches of the UPR that has previously been demonstrated.
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Affiliation(s)
- Yanjun Ma
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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Hayashi T, Saito A, Okuno S, Ferrand-Drake M, Dodd RL, Chan PH. Oxidative injury to the endoplasmic reticulum in mouse brains after transient focal ischemia. Neurobiol Dis 2004; 15:229-39. [PMID: 15006693 DOI: 10.1016/j.nbd.2003.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2003] [Revised: 10/06/2003] [Accepted: 10/10/2003] [Indexed: 02/02/2023] Open
Abstract
Oxidative damage to the endoplasmic reticulum (ER) could be involved in ischemic neuronal cell death because this organelle is susceptible to reactive oxygen species. Using wild-type mice and copper/zinc-superoxide dismutase (SOD1) transgenic mice, we induced focal cerebral ischemia and compared neuronal degeneration and ER stress, that is, phosphorylation of eukaryotic initiation factor 2alpha (eIF2alpha) and RNA-dependent protein kinase-like ER eIF2alpha kinase (PERK). We found that neurons with severe and prolonged phosphorylation of eIF2alpha and PERK underwent later degeneration, and that this was partially prevented by SOD1 overexpression. Signals for superoxide production and phospho-PERK were colocalized, which further indicates a pivotal role for superoxide in ER damage. We investigated the molecular mechanisms of oxidative ER stress and found that detachment of glucose-regulated protein 78 from PERK was the key step. We conclude that ER damage is involved in oxidative neuronal injury in the brain after ischemia/reperfusion.
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Affiliation(s)
- Takeshi Hayashi
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA
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Jousse C, Averous J, Bruhat A, Carraro V, Mordier S, Fafournoux P. Amino acids as regulators of gene expression: molecular mechanisms. Biochem Biophys Res Commun 2004; 313:447-52. [PMID: 14684183 DOI: 10.1016/j.bbrc.2003.07.020] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Regulation of gene expression by nutrients in mammals is an important mechanism allowing them to adapt their physiological functions according to the supply of nutrient in the diet. It has been shown recently that amino acids are able to regulate by themselves the expression of numerous genes. CHOP, asparagine synthetase, and IGFBP-1 regulation following AA starvation will be described in this review with special interest in the molecular mechanisms involved.
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Affiliation(s)
- Céline Jousse
- Unité de Nutrition et Métabolisme Protéique, Institut National de la Recherche Agronomique de Theix, 63122 Saint Genès Champanelle, France
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Hayashi T, Saito A, Okuno S, Ferrand-Drake M, Dodd RL, Nishi T, Maier CM, Kinouchi H, Chan PH. Oxidative damage to the endoplasmic reticulum is implicated in ischemic neuronal cell death. J Cereb Blood Flow Metab 2003; 23:1117-28. [PMID: 14526222 DOI: 10.1097/01.wcb.0000089600.87125.ad] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The endoplasmic reticulum (ER), which plays important roles in apoptosis, is susceptible to oxidative stress. Because reactive oxygen species (ROS) are robustly produced in the ischemic brain, ER damage by ROS may be implicated in ischemic neuronal cell death. We induced global brain ischemia on wild-type and copper/zinc superoxide dismutase (SOD1) transgenic rats and compared ER stress and neuronal damage. Phosphorylated forms of eukaryotic initiation factor 2 alpha (eIF2 alpha) and RNA-dependent protein kinase-like ER eIF2 alpha kinase (PERK), both of which play active roles in apoptosis, were increased in hippocampal CA1 neurons after ischemia but to a lesser degree in the transgenic animals. This finding, together with the finding that the transgenic animals showed decreased neuronal degeneration, indicates that oxidative ER damage is involved in ischemic neuronal cell death. To elucidate the mechanisms of ER damage by ROS, we analyzed glucose-regulated protein 78 (GRP78) binding with PERK and oxidative ER protein modification. The proteins were oxidatively modified and stagnated in the ER lumen, and GRP78 was detached from PERK by ischemia, all of which were attenuated by SOD1 overexpression. We propose that ROS attack and modify ER proteins and elicit ER stress response, which results in neuronal cell death.
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Affiliation(s)
- Takeshi Hayashi
- Department of Neurosurgery and Program in Neurosciences, Stanford University School of Medicine, California 94305, USA
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