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Ouyang F, Yuan P, Ju Y, Chen W, Peng Z, Xu H. Alzheimer's disease as a causal risk factor for diabetic retinopathy: a Mendelian randomization study. Front Endocrinol (Lausanne) 2024; 15:1340608. [PMID: 38699385 PMCID: PMC11064697 DOI: 10.3389/fendo.2024.1340608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 04/05/2024] [Indexed: 05/05/2024] Open
Abstract
Objectives This study aims to investigate the causal relationship between Alzheimer's Disease (AD) and Diabetic Retinopathy (DR). Methods Employing Mendelian Randomization (MR), Generalized Summary-data-based Mendelian Randomization (GSMR), and the MR-Steiger test, this study scrutinizes the genetic underpinnings of the hypothesized causal association between AD and DR, as well as its Proliferative DR (PDR) and Non-Proliferative DR (NPDR) subtypes. Comprehensive data from Genome-Wide Association Studies (GWAS) were analyzed, specifically AD data from the Psychiatric Genomics Consortium (71,880 cases/383,378 controls), and DR, PDR, and NPDR data from both the FinnGen consortium (FinnGen release R8, DR: 5,988 cases/314,042 controls; PDR: 8,383 cases/329,756 controls; NPDR: 3,446 cases/314,042 controls) and the IEU OpenGWAS (DR: 14,584 cases/176,010 controls; PDR: 8,681 cases/204,208 controls; NPDR: 2,026 cases/204,208 controls). The study also incorporated Functional Mapping and Annotation (FUMA) for an in-depth analysis of the GWAS results. Results The MR analyses revealed that genetic susceptibility to AD significantly increases the risk of DR, as evidenced by GWAS data from the FinnGen consortium (OR: 2.5090; 95% confidence interval (CI):1.2102-5.2018, false discovery rate P-value (PFDR)=0.0201; GSMR: bxy=0.8936, bxy_se=0.3759, P=0.0174), NPDR (OR: 2.7455; 95% CI: 1.3178-5.7197, PFDR=0.0166; GSMR: bxy=0.9682, bxy_se=0.3802, P=0.0126), and PDR (OR: 2.3098; 95% CI: 1.2411-4.2986, PFDR=0.0164; GSMR: bxy=0.7962, bxy_se=0.3205, P=0.0129) using DR GWAS from FinnGen consortium. These results were corroborated by DR GWAS datasets from IEU OpenGWAS. The MR-Steiger test confirmed a significant association of all identified instrumental variables (IVs) with AD. While a potential causal effect of DR and its subtypes on AD was identified, the robustness of these results was constrained by a low power value. FUMA analysis identified OARD1, NFYA, TREM1 as shared risk genes between DR and AD, suggesting a potential genetic overlap between these complex diseases. Discussion This study underscores the contribution of AD to an increased risk of DR, as well as NPDR and PDR subtypes, underscoring the necessity of a holistic approach in the management of patients affected by these conditions.
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Affiliation(s)
- Fu Ouyang
- Department of Neurology, the Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China
| | - Ping Yuan
- Department of Neurology, the Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China
| | - Yaxin Ju
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wei Chen
- Department of Neurology, the Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China
| | - Zijun Peng
- Department of Neurology, the Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China
| | - Hongbei Xu
- Department of Neurology, the Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China
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Pierre AS, Gavriel N, Guilbard M, Ogier-Denis E, Chevet E, Delom F, Igbaria A. Modulation of Protein Disulfide Isomerase Functions by Localization: The Example of the Anterior Gradient Family. Antioxid Redox Signal 2024. [PMID: 38411504 DOI: 10.1089/ars.2024.0561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Significance: Oxidative folding within the endoplasmic reticulum (ER) introduces disulfide bonds into nascent polypeptides, ensuring proteins' stability and proper functioning. Consequently, this process is critical for maintaining proteome integrity and overall health. The productive folding of thousands of secretory proteins requires stringent quality control measures, such as the unfolded protein response (UPR) and ER-Associated Degradation (ERAD), which contribute significantly to maintaining ER homeostasis. ER-localized protein disulfide isomerases (PDIs) play an essential role in each of these processes, thereby contributing to various aspects of ER homeostasis, including maintaining redox balance, proper protein folding, and signaling from the ER to the nucleus. Recent Advances: Over the years, there have been increasing reports of the (re)localization of PDI family members and other ER-localized proteins to various compartments. A prime example is the anterior gradient (AGR) family of PDI proteins, which have been reported to relocate to the cytosol or the extracellular environment, acquiring gain of functions that intersect with various cellular signaling pathways. Critical Issues: Here, we summarize the functions of PDIs and their gain or loss of functions in non-ER locations. We will focus on the activity, localization, and function of the AGR proteins: AGR1, AGR2, and AGR3. Future Directions: Targeting PDIs in general and AGRs in particular is a promising strategy in different human diseases. Thus, there is a need for innovative strategies and tools aimed at targeting PDIs; those strategies should integrate the specific localization and newly acquired functions of these PDIs rather than solely focusing on their canonical roles.
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Affiliation(s)
- Arvin S Pierre
- INSERM U1242, University of Rennes, Rennes, France
- Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Noa Gavriel
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Marianne Guilbard
- ARTiSt Group, Univ. Bordeaux, INSERM U1312, Institut Bergonié, Bordeaux, France
- Thabor Therapeutics, Paris, France
| | - Eric Ogier-Denis
- INSERM U1242, University of Rennes, Rennes, France
- Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Eric Chevet
- INSERM U1242, University of Rennes, Rennes, France
- Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Frederic Delom
- ARTiSt Group, Univ. Bordeaux, INSERM U1312, Institut Bergonié, Bordeaux, France
| | - Aeid Igbaria
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
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3
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Lei Y, Yu H, Ding S, Liu H, Liu C, Fu R. Molecular mechanism of ATF6 in unfolded protein response and its role in disease. Heliyon 2024; 10:e25937. [PMID: 38434326 PMCID: PMC10907738 DOI: 10.1016/j.heliyon.2024.e25937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/04/2024] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
Activating transcription factor 6 (ATF6), an important signaling molecule in unfolded protein response (UPR), plays a role in the pathogenesis of several diseases, including diseases such as congenital retinal disease, liver fibrosis and ankylosing spondylitis. After endoplasmic reticulum stress (ERS), ATF6 is activated after separation from binding immunoglobulin protein (GRP78/BiP) in the endoplasmic reticulum (ER) and transported to the Golgi apparatus to be hydrolyzed by site 1 and site 2 proteases into ATF6 fragments, which localize to the nucleus and regulate the transcription and expression of ERS-related genes. In these diseases, ERS leads to the activation of UPR, which ultimately lead to the occurrence and development of diseases by regulating the physiological state of cells through the ATF6 signaling pathway. Here, we discuss the evidence for the pathogenic importance of ATF6 signaling in different diseases and discuss preclinical results.
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Affiliation(s)
| | | | - Shaoxue Ding
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Hui Liu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Chunyan Liu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Rong Fu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
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Gil-Jaramillo N, Aristizábal-Pachón AF, Luque Aleman MA, González Gómez V, Escobar Hurtado HD, Girón Pinto LC, Jaime Camacho JS, Rojas-Cruz AF, González-Giraldo Y, Pinzón A, González J. Competing endogenous RNAs in human astrocytes: crosstalk and interacting networks in response to lipotoxicity. Front Neurosci 2023; 17:1195840. [PMID: 38027526 PMCID: PMC10679742 DOI: 10.3389/fnins.2023.1195840] [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: 03/29/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Neurodegenerative diseases (NDs) are characterized by a progressive deterioration of neuronal function, leading to motor and cognitive damage in patients. Astrocytes are essential for maintaining brain homeostasis, and their functional impairment is increasingly recognized as central to the etiology of various NDs. Such impairment can be induced by toxic insults with palmitic acid (PA), a common fatty acid, that disrupts autophagy, increases reactive oxygen species, and triggers inflammation. Although the effects of PA on astrocytes have been addressed, most aspects of the dynamics of this fatty acid remain unknown. Additionally, there is still no model that satisfactorily explains how astroglia goes from being neuroprotective to neurotoxic. Current incomplete knowledge needs to be improved by the growing field of non-coding RNAs (ncRNAs), which is proven to be related to NDs, where the complexity of the interactions among these molecules and how they control other RNA expressions need to be addressed. In the present study, we present an extensive competing endogenous RNA (ceRNA) network using transcriptomic data from normal human astrocyte (NHA) cells exposed to PA lipotoxic conditions and experimentally validated data on ncRNA interaction. The obtained network contains 7 lncRNA transcripts, 38 miRNAs, and 239 mRNAs that showed enrichment in ND-related processes, such as fatty acid metabolism and biosynthesis, FoxO and TGF-β signaling pathways, prion diseases, apoptosis, and immune-related pathways. In addition, the transcriptomic profile was used to propose 22 potential key controllers lncRNA/miRNA/mRNA axes in ND mechanisms. The relevance of five of these axes was corroborated by the miRNA expression data obtained in other studies. MEG3 (ENST00000398461)/hsa-let-7d-5p/ATF6B axis showed importance in Parkinson's and late Alzheimer's diseases, while AC092687.3/hsa-let-7e-5p/[SREBF2, FNIP1, PMAIP1] and SDCBP2-AS1 (ENST00000446423)/hsa-miR-101-3p/MAPK6 axes are probably related to Alzheimer's disease development and pathology. The presented network and axes will help to understand the PA-induced mechanisms in astrocytes, leading to protection or injury in the CNS under lipotoxic conditions as part of the intricated cellular regulation influencing the pathology of different NDs. Furthermore, the five corroborated axes could be considered study targets for new pharmacologic treatments or as possible diagnostic molecules, contributing to improving the quality of life of millions worldwide.
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Affiliation(s)
- Natalia Gil-Jaramillo
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | | | - María Alejandra Luque Aleman
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Valentina González Gómez
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Hans Deyvy Escobar Hurtado
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Laura Camila Girón Pinto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Juan Sebastian Jaime Camacho
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Alexis Felipe Rojas-Cruz
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Yeimy González-Giraldo
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Andrés Pinzón
- Laboratorio de Bioinformática y Biología de Sistemas, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Janneth González
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
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5
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Feng T, Zhao R, Zhang H, Sun F, Hu J, Wang M, Qi M, Liu L, Gao L, Xiao Y, Zhen J, Chen W, Wang L, Han B. Reciprocal negative feedback regulation of ATF6α and PTEN promotes prostate cancer progression. Cell Mol Life Sci 2023; 80:292. [PMID: 37715829 PMCID: PMC11073217 DOI: 10.1007/s00018-023-04940-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/14/2023] [Accepted: 08/04/2023] [Indexed: 09/18/2023]
Abstract
Phosphatase and tensin homolog (PTEN) loss tightly correlates with prostate cancer (PCa) progression and metastasis. Inactivation of PTEN leads to abnormal activation of PI3K/AKT pathway. However, results from clinical trials with AKT inhibitors in PCa have been largely disappointing. Identification of novel regulators of PTEN in PTEN-dysfunctional PCa is urgently needed. Here we demonstrated that the expression level of PTEN is inversely correlated with the signature score of unfolded protein response (UPR) in PCa. Importantly, PTEN suppresses the activity of ATF6α, via interacting to de-phosphorylate ATF6α and consequently inhibiting its nuclear translocation. Conversely, ATF6α promotes the ubiquitination and degradation of PTEN by inducing CHIP expression. Thus, ATF6α and PTEN forms a negative feedback loop during PCa progression. Combination of ATF6α inhibitor with AKT inhibitor suppresses tumor cell proliferation and xenograft growth. Importantly, this study highlighted ATF6α as a therapeutic vulnerability in PTEN dysfunctional PCa.
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Affiliation(s)
- Tingting Feng
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Ru Zhao
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Hanwen Zhang
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Feifei Sun
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Jing Hu
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Meng Wang
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Mei Qi
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Ling Liu
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Lin Gao
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Yabo Xiao
- School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Junhui Zhen
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Weiwen Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Shandong University, Jinan, Shandong, China
| | - Lin Wang
- Biomedical Sciences College and Shandong Medicinal Biotechnology Centre, NHC Key Laboratory of Biotechnology Drugs, Key Lab for Rare and Uncommon Diseases of Shandong Province, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.
- Department of Oncology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, China.
| | - Bo Han
- The Key Laboratory of Experimental Teratology, Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China.
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, Shandong, China.
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6
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Trouvé P, Férec C, Génin E. The Interplay between the Unfolded Protein Response, Inflammation and Infection in Cystic Fibrosis. Cells 2021; 10:2980. [PMID: 34831204 PMCID: PMC8616505 DOI: 10.3390/cells10112980] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/25/2021] [Accepted: 10/29/2021] [Indexed: 12/15/2022] Open
Abstract
In cystic fibrosis (CF), p.Phe508del is the most frequent mutation in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. The p.Phe508del-CFTR protein is retained in the ER and rapidly degraded. This retention likely triggers an atypical Unfolded Protein Response (UPR) involving ATF6, which reduces the expression of p.Phe508del-CFTR. There are still some debates on the role of the UPR in CF: could it be triggered by the accumulation of misfolded CFTR proteins in the endoplasmic reticulum as was proposed for the most common CFTR mutation p.Phe508del? Or, is it the consequence of inflammation and infection that occur in the disease? In this review, we summarize recent findings on UPR in CF and show how infection, inflammation and UPR act together in CF. We propose to rethink their respective role in CF and to consider them as a whole.
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Affiliation(s)
- Pascal Trouvé
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.F.); (E.G.)
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Nguyen DT, Le TM, Hattori T, Takarada-Iemata M, Ishii H, Roboon J, Tamatani T, Kannon T, Hosomichi K, Tajima A, Taniuchi S, Miyake M, Oyadomari S, Tanaka T, Kato N, Saito S, Mori K, Hori O. The ATF6β-calreticulin axis promotes neuronal survival under endoplasmic reticulum stress and excitotoxicity. Sci Rep 2021; 11:13086. [PMID: 34158584 PMCID: PMC8219835 DOI: 10.1038/s41598-021-92529-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023] Open
Abstract
While ATF6α plays a central role in the endoplasmic reticulum (ER) stress response, the function of its paralogue ATF6β remains elusive, especially in the central nervous system (CNS). Here, we demonstrate that ATF6β is highly expressed in the hippocampus of the brain, and specifically regulates the expression of calreticulin (CRT), a molecular chaperone in the ER with a high Ca2+-binding capacity. CRT expression was reduced to ~ 50% in the CNS of Atf6b−/− mice under both normal and ER stress conditions. Analysis using cultured hippocampal neurons revealed that ATF6β deficiency reduced Ca2+ stores in the ER and enhanced ER stress-induced death. The higher levels of death in Atf6b−/− neurons were recovered by ATF6β and CRT overexpressions, or by treatment with Ca2+-modulating reagents such as BAPTA-AM and 2-APB, and with an ER stress inhibitor salubrinal. In vivo, kainate-induced neuronal death was enhanced in the hippocampi of Atf6b−/− and Calr+/− mice, and restored by administration of 2-APB and salubrinal. These results suggest that the ATF6β-CRT axis promotes neuronal survival under ER stress and excitotoxity by improving intracellular Ca2+ homeostasis.
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Affiliation(s)
- Dinh Thi Nguyen
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan
| | - Thuong Manh Le
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan.,Department of Human Anatomy, Hanoi Medical University, Hanoi, Vietnam
| | - Tsuyoshi Hattori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan
| | - Mika Takarada-Iemata
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan
| | - Hiroshi Ishii
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan
| | - Jureepon Roboon
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan
| | - Takashi Tamatani
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan
| | - Takayuki Kannon
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kazuyoshi Hosomichi
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Atsushi Tajima
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Shusuke Taniuchi
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Masato Miyake
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Seiichi Oyadomari
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Takashi Tanaka
- Department of Anatomy II, Kanazawa Medical University, Kahoku, Japan
| | - Nobuo Kato
- Department of Physiology I, Kanazawa Medical University, Kahoku, Japan
| | - Shunsuke Saito
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Kazutoshi Mori
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Osamu Hori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-Machi, Kanazawa City, Ishikawa, 920-8640, Japan.
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Mustapha S, Mohammed M, Azemi AK, Yunusa I, Shehu A, Mustapha L, Wada Y, Ahmad MH, Ahmad WANW, Rasool AHG, Mokhtar SS. Potential Roles of Endoplasmic Reticulum Stress and Cellular Proteins Implicated in Diabesity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:8830880. [PMID: 33995826 PMCID: PMC8099518 DOI: 10.1155/2021/8830880] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 03/28/2021] [Accepted: 04/05/2021] [Indexed: 12/12/2022]
Abstract
The role of the endoplasmic reticulum (ER) has evolved from protein synthesis, processing, and other secretory pathways to forming a foundation for lipid biosynthesis and other metabolic functions. Maintaining ER homeostasis is essential for normal cellular function and survival. An imbalance in the ER implied stressful conditions such as metabolic distress, which activates a protective process called unfolded protein response (UPR). This response is activated through some canonical branches of ER stress, i.e., the protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1α (IRE1α), and activating transcription factor 6 (ATF6). Therefore, chronic hyperglycemia, hyperinsulinemia, increased proinflammatory cytokines, and free fatty acids (FFAs) found in diabesity (a pathophysiological link between obesity and diabetes) could lead to ER stress. However, limited data exist regarding ER stress and its association with diabesity, particularly the implicated proteins and molecular mechanisms. Thus, this review highlights the role of ER stress in relation to some proteins involved in diabesity pathogenesis and provides insight into possible pathways that could serve as novel targets for therapeutic intervention.
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Affiliation(s)
- Sagir Mustapha
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
- Department of Pharmacology and Therapeutics, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Mustapha Mohammed
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Pulau Pinang, Malaysia
- Department of Clinical Pharmacy and Pharmacy Practice, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Ahmad Khusairi Azemi
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Ismaeel Yunusa
- Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina, College of Pharmacy, Columbia, SC, USA
| | - Aishatu Shehu
- Department of Pharmacology and Therapeutics, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Lukman Mustapha
- Department of Pharmaceutical and Medicinal Chemistry, Kaduna State University, Kaduna, Nigeria
| | - Yusuf Wada
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
- Department of Zoology, Ahmadu Bello University Zaria, Kaduna, Nigeria
| | - Mubarak Hussaini Ahmad
- Department of Pharmacology and Therapeutics, Ahmadu Bello University Zaria, Kaduna, Nigeria
- School of Pharmacy Technician, Aminu Dabo College of Health Sciences and Technology, Kano, Nigeria
| | - Wan Amir Nizam Wan Ahmad
- Biomedicine Programme, School of Health Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Aida Hanum Ghulam Rasool
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
- Hospital Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
| | - Siti Safiah Mokhtar
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia
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Delgado-Benito V, Berruezo-Llacuna M, Altwasser R, Winkler W, Sundaravinayagam D, Balasubramanian S, Caganova M, Graf R, Rahjouei A, Henke MT, Driesner M, Keller L, Prigione A, Janz M, Akalin A, Di Virgilio M. PDGFA-associated protein 1 protects mature B lymphocytes from stress-induced cell death and promotes antibody gene diversification. J Exp Med 2021; 217:151913. [PMID: 32609329 PMCID: PMC7537392 DOI: 10.1084/jem.20200137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/20/2020] [Accepted: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
The establishment of protective humoral immunity is dependent on the ability of mature B cells to undergo antibody gene diversification while adjusting to the physiological stressors induced by activation with the antigen. Mature B cells diversify their antibody genes by class switch recombination (CSR) and somatic hypermutation (SHM), which are both dependent on efficient induction of activation-induced cytidine deaminase (AID). Here, we identified PDGFA-associated protein 1 (Pdap1) as an essential regulator of cellular homeostasis in mature B cells. Pdap1 deficiency leads to sustained expression of the integrated stress response (ISR) effector activating transcription factor 4 (Atf4) and induction of the ISR transcriptional program, increased cell death, and defective AID expression. As a consequence, loss of Pdap1 reduces germinal center B cell formation and impairs CSR and SHM. Thus, Pdap1 protects mature B cells against chronic ISR activation and ensures efficient antibody diversification by promoting their survival and optimal function.
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Affiliation(s)
- Verónica Delgado-Benito
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Maria Berruezo-Llacuna
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Robert Altwasser
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Bioinformatics and Omics Data Science Technology Platform, Berlin Institute of Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Wiebke Winkler
- Laboratory of Immune Regulation and Cancer, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Laboratory of Biology of Malignant Lymphomas, Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité, University Medicine, Berlin, Germany
| | - Devakumar Sundaravinayagam
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sandhya Balasubramanian
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Marieta Caganova
- Laboratory of Immune Regulation and Cancer, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Robin Graf
- Laboratory of Immune Regulation and Cancer, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Ali Rahjouei
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Marie-Thérèse Henke
- Laboratory of Mitochondria and Cell Fate Reprogramming, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Madlen Driesner
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Lisa Keller
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Alessandro Prigione
- Laboratory of Mitochondria and Cell Fate Reprogramming, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich Heine University, Düsseldorf, Germany
| | - Martin Janz
- Laboratory of Biology of Malignant Lymphomas, Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité, University Medicine, Berlin, Germany
| | - Altuna Akalin
- Bioinformatics and Omics Data Science Technology Platform, Berlin Institute of Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Michela Di Virgilio
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité-Universitätsmedizin Berlin, Berlin, Germany
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10
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Kumar V, Maity S. ER Stress-Sensor Proteins and ER-Mitochondrial Crosstalk-Signaling Beyond (ER) Stress Response. Biomolecules 2021; 11:173. [PMID: 33525374 PMCID: PMC7911976 DOI: 10.3390/biom11020173] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/14/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023] Open
Abstract
Recent studies undoubtedly show the importance of inter organellar connections to maintain cellular homeostasis. In normal physiological conditions or in the presence of cellular and environmental stress, each organelle responds alone or in coordination to maintain cellular function. The Endoplasmic reticulum (ER) and mitochondria are two important organelles with very specialized structural and functional properties. These two organelles are physically connected through very specialized proteins in the region called the mitochondria-associated ER membrane (MAM). The molecular foundation of this relationship is complex and involves not only ion homeostasis through the shuttling of calcium but also many structural and apoptotic proteins. IRE1alpha and PERK are known for their canonical function as an ER stress sensor controlling unfolded protein response during ER stress. The presence of these transmembrane proteins at the MAM indicates its potential involvement in other biological functions beyond ER stress signaling. Many recent studies have now focused on the non-canonical function of these sensors. In this review, we will focus on ER mitochondrial interdependence with special emphasis on the non-canonical role of ER stress sensors beyond ER stress.
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11
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Grandjean JMD, Wiseman RL. Small molecule strategies to harness the unfolded protein response: where do we go from here? J Biol Chem 2020; 295:15692-15711. [PMID: 32887796 PMCID: PMC7667976 DOI: 10.1074/jbc.rev120.010218] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/02/2020] [Indexed: 12/31/2022] Open
Abstract
The unfolded protein response (UPR) plays a central role in regulating endoplasmic reticulum (ER) and global cellular physiology in response to pathologic ER stress. The UPR is comprised of three signaling pathways activated downstream of the ER membrane proteins IRE1, ATF6, and PERK. Once activated, these proteins initiate transcriptional and translational signaling that functions to alleviate ER stress, adapt cellular physiology, and dictate cell fate. Imbalances in UPR signaling are implicated in the pathogenesis of numerous, etiologically-diverse diseases, including many neurodegenerative diseases, protein misfolding diseases, diabetes, ischemic disorders, and cancer. This has led to significant interest in establishing pharmacologic strategies to selectively modulate IRE1, ATF6, or PERK signaling to both ameliorate pathologic imbalances in UPR signaling implicated in these different diseases and define the importance of the UPR in diverse cellular and organismal contexts. Recently, there has been significant progress in the identification and characterization of UPR modulating compounds, providing new opportunities to probe the pathologic and potentially therapeutic implications of UPR signaling in human disease. Here, we describe currently available UPR modulating compounds, specifically highlighting the strategies used for their discovery and specific advantages and disadvantages in their application for probing UPR function. Furthermore, we discuss lessons learned from the application of these compounds in cellular and in vivo models to identify favorable compound properties that can help drive the further translational development of selective UPR modulators for human disease.
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Affiliation(s)
- Julia M D Grandjean
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA.
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12
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Stengel ST, Fazio A, Lipinski S, Jahn MT, Aden K, Ito G, Wottawa F, Kuiper JW, Coleman OI, Tran F, Bordoni D, Bernardes JP, Jentzsch M, Luzius A, Bierwirth S, Messner B, Henning A, Welz L, Kakavand N, Falk-Paulsen M, Imm S, Hinrichsen F, Zilbauer M, Schreiber S, Kaser A, Blumberg R, Haller D, Rosenstiel P. Activating Transcription Factor 6 Mediates Inflammatory Signals in Intestinal Epithelial Cells Upon Endoplasmic Reticulum Stress. Gastroenterology 2020; 159:1357-1374.e10. [PMID: 32673694 PMCID: PMC7923714 DOI: 10.1053/j.gastro.2020.06.088] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 05/18/2020] [Accepted: 06/18/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Excess and unresolved endoplasmic reticulum (ER) stress in intestinal epithelial cells (IECs) promotes intestinal inflammation. Activating transcription factor 6 (ATF6) is one of the signaling mediators of ER stress. We studied the pathways that regulate ATF6 and its role for inflammation in IECs. METHODS We performed an RNA interference screen, using 23,349 unique small interfering RNAs targeting 7783 genes and a luciferase reporter controlled by an ATF6-dependent ERSE (ER stress-response element) promoter, to identify proteins that activate or inhibit the ATF6 signaling pathway in HEK293 cells. To validate the screening results, intestinal epithelial cell lines (Caco-2 cells) were transfected with small interfering RNAs or with a plasmid overexpressing a constitutively active form of ATF6. Caco-2 cells with a CRISPR-mediated disruption of autophagy related 16 like 1 gene (ATG16L1) were used to study the effect of ATF6 on ER stress in autophagy-deficient cells. We also studied intestinal organoids derived from mice that overexpress constitutively active ATF6, from mice with deletion of the autophagy related 16 like 1 or X-Box binding protein 1 gene in IECs (Atg16l1ΔIEC or Xbp1ΔIEC, which both develop spontaneous ileitis), from patients with Crohn's disease (CD) and healthy individuals (controls). Cells and organoids were incubated with tunicamycin to induce ER stress and/or chemical inhibitors of newly identified activator proteins of ATF6 signaling, and analyzed by real-time polymerase chain reaction and immunoblots. Atg16l1ΔIEC and control (Atg16l1fl/fl) mice were given intraperitoneal injections of tunicamycin and were treated with chemical inhibitors of ATF6 activating proteins. RESULTS We identified and validated 15 suppressors and 7 activators of the ATF6 signaling pathway; activators included the regulatory subunit of casein kinase 2 (CSNK2B) and acyl-CoA synthetase long chain family member 1 (ACSL1). Knockdown or chemical inhibition of CSNK2B and ACSL1 in Caco-2 cells reduced activity of the ATF6-dependent ERSE reporter gene, diminished transcription of the ATF6 target genes HSP90B1 and HSPA5 and reduced NF-κB reporter gene activation on tunicamycin stimulation. Atg16l1ΔIEC and or Xbp1ΔIEC organoids showed increased expression of ATF6 and its target genes. Inhibitors of ACSL1 or CSNK2B prevented activation of ATF6 and reduced CXCL1 and tumor necrosis factor (TNF) expression in these organoids on induction of ER stress with tunicamycin. Injection of mice with inhibitors of ACSL1 or CSNK2B significantly reduced tunicamycin-mediated intestinal inflammation and IEC death and expression of CXCL1 and TNF in Atg16l1ΔIEC mice. Purified ileal IECs from patients with CD had higher levels of ATF6, CSNK2B, and HSPA5 messenger RNAs than controls; early-passage organoids from patients with active CD show increased levels of activated ATF6 protein, incubation of these organoids with inhibitors of ACSL1 or CSNK2B reduced transcription of ATF6 target genes, including TNF. CONCLUSIONS Ileal IECs from patients with CD have higher levels of activated ATF6, which is regulated by CSNK2B and HSPA5. ATF6 increases expression of TNF and other inflammatory cytokines in response to ER stress in these cells and in organoids from Atg16l1ΔIEC and Xbp1ΔIEC mice. Strategies to inhibit the ATF6 signaling pathway might be developed for treatment of inflammatory bowel diseases.
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Affiliation(s)
- Stephanie T. Stengel
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Antonella Fazio
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Simone Lipinski
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Martin T. Jahn
- RD3 Marine Microbiology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
| | - Konrad Aden
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany,Department of Internal Medicine I., Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Go Ito
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany,Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Felix Wottawa
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Jan W.P. Kuiper
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Olivia I. Coleman
- Chair of Nutrition and Immunology, Technische Universität München, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Florian Tran
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany,Department of Internal Medicine I., Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Dora Bordoni
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Joana P. Bernardes
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Marlene Jentzsch
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Anne Luzius
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Sandra Bierwirth
- Chair of Nutrition and Immunology, Technische Universität München, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Berith Messner
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Anna Henning
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Lina Welz
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Nassim Kakavand
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Maren Falk-Paulsen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Simon Imm
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Finn Hinrichsen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Matthias Zilbauer
- Department of Pediatrics, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, England, UK MA
| | - Stefan Schreiber
- Department of Internal Medicine I., Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Arthur Kaser
- Division of Gastroenterology and Hepatology, Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 0QQ, England, UK MA
| | - Richard Blumberg
- Gastroenterology Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, US
| | - Dirk Haller
- Chair of Nutrition and Immunology, Technische Universität München, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
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13
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Yan X, Wu S, Liu Q, Li Y, Zhu W, Zhang J. Accumulation of Asn450Tyr mutant myocilin in ER promotes apoptosis of human trabecular meshwork cells. Mol Vis 2020; 26:563-573. [PMID: 32818018 PMCID: PMC7406863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 07/27/2020] [Indexed: 11/30/2022] Open
Abstract
PURPOSE In a previous study, we identified the Asn450Tyr mutant myocilin gene (Myoc-N450Y) in the pedigree of families with juvenile open angle glaucoma (JOAG), but whether N450Y is a pathogenic mutation remained to be determined. The present study aimed at exploring the role of Myoc-N450Y in primary human trabecular meshwork (HTM) cells. METHODS Primary HTM cells were infected with lentivirus with wild-type myocilin (Myoc-WT) or Myoc-N450Y. Primary HTM cells overexpressing Myoc-WT or Myoc-N450Y was treated with sodium 4-phenylbutyrate (4-PBA) or not. The secretion and intracellular distribution of Myoc were analyzed with western blotting and immunofluorescence. Expression of endoplasmic reticulum (ER) stress-related proteins was detected with quantitative real-time PCR (qRT-PCR) and western blotting. Cell viability, apoptosis, and expression of the related proteins were examined with Cell Counting Kit-8 (CCK-8), flow cytometry analysis, and western blotting, respectively. RESULTS We found that non-secretion of Myoc-N450Y induced ER stress by colocalization with the ER marker calreticulin (CALR), and upregulating the expression of ER stress markers in primary HTM cells. Moreover, overexpression of Myoc-N450Y inhibited the viability and induced apoptosis of primary HTM cells, and inhibition of PI3K/AKT signaling was induced by ER stress. Reduction in ER stress with 4-PBA decreased the level of ER stress markers, promoted secretion, and prevented accumulation of myocilin in the Myoc-N450Y group. Apoptosis was rescued, and inhibition of PI3K/AKT signaling was reversed, after PBA treatment in primary HTM cells with Myoc-N450Y overexpression. CONCLUSIONS The study results suggest that Myoc-N450Y promotes apoptosis of primary HTM cells via the ER stress-induced apoptosis pathway, in which the PI3K/AKT signaling pathway plays a crucial role.
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Affiliation(s)
- Xuejing Yan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Yang Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Wei Zhu
- Department of Pharmacology, Qingdao University School of Pharmacy, Qingdao, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
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14
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van Ziel AM, Scheper W. The UPR in Neurodegenerative Disease: Not Just an Inside Job. Biomolecules 2020; 10:biom10081090. [PMID: 32707908 PMCID: PMC7465596 DOI: 10.3390/biom10081090] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/16/2020] [Accepted: 07/20/2020] [Indexed: 12/26/2022] Open
Abstract
Neurons are highly specialized cells that continuously and extensively communicate with other neurons, as well as glia cells. During their long lifetime, the post-mitotic neurons encounter many stressful situations that can disrupt protein homeostasis (proteostasis). The importance of tight protein quality control is illustrated by neurodegenerative disorders where disturbed neuronal proteostasis causes neuronal dysfunction and loss. For their unique function, neurons require regulated and long-distance transport of membrane-bound cargo and organelles. This highlights the importance of protein quality control in the neuronal endomembrane system, to which the unfolded protein response (UPR) is instrumental. The UPR is a highly conserved stress response that is present in all eukaryotes. However, recent studies demonstrate the existence of cell-type-specific aspects of the UPR, as well as cell non-autonomous UPR signaling. Here we discuss these novel insights in view of the complex cellular architecture of the brain and the implications for neurodegenerative diseases.
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Affiliation(s)
- Anna Maria van Ziel
- Department of Clinical Genetics, Amsterdam University Medical Centers location VUmc, 1081 HV Amsterdam, The Netherlands;
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit (VU), 1081 HV Amsterdam, The Netherlands
| | - Wiep Scheper
- Department of Clinical Genetics, Amsterdam University Medical Centers location VUmc, 1081 HV Amsterdam, The Netherlands;
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit (VU), 1081 HV Amsterdam, The Netherlands
- Correspondence: ; Tel.: +31-20-5982771
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15
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Cao XF, Jiang GZ, Xu C, Abasubong KP, Wang CC, Liu WB. Molecular characterization and expression pattern of inositol-requiring enzyme 1 (IRE1) in blunt snout bream (Megalobrama amblycephala): its role of IRE1 involved in inflammatory response induced by lipopolysaccharide. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:843-860. [PMID: 31981002 DOI: 10.1007/s10695-019-00753-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/26/2019] [Indexed: 06/10/2023]
Abstract
This study aimed to characterize the full-length cDNA of IRE1 from fish Megalobrama amblycephala and investigate its role in the pro-inflammatory response. A full-length cDNA coding IRE1 was cloned from blunt snout bream by RT-PCR and RACE approaches. The cDNA obtained covered 3665 bp with an open reading frame of 3096 bp encoding 1031 amino acids. Sequence alignment and phylogenetic analysis revealed a high degree of conservation (74-92%) among various species, retaining one signal peptide, one luminal domain, one serine/threonine kinase domain, one RNase domain, one activation loop, two N-linked glycosylation sites, and several phosphorylation sites. The highest IRE1 expression was observed in the trunk kidney followed by the brain and spleen, whereas relatively low expression levels were detected in the liver, intestine, adipose, skin, and heart. After lipopolysaccharide (LPS) challenge, the expressions of glucose-regulated protein 78 (GRP78), inositol-requiring enzyme 1 (IRE1), spliced X-box binding protein 1 (XBP1s), C/EBP homologous protein (CHOP), nuclear factor kappa B (NF-κB), tumor necrosis factor alpha (TNFα), and interleukin-6 (IL-6) all increased remarkably in the spleen and brain at different sampling time points, while LPS also upregulated all the genes tested in the intestine except C/EBP homologous protein. Overall, the results indicated that the IRE1 gene of Megalobrama amblycephala shared a high similarity compared with other vertebrates including several bony fish species. Its expression in three tissues was induced remarkably by the LPS challenge, which indicated that IRE1 played a vital role in LPS-induced inflammation on fish.
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Affiliation(s)
- Xiu-Fei Cao
- Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, People's Republic of China
| | - Guang-Zhen Jiang
- Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, People's Republic of China
| | - Chao Xu
- Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, People's Republic of China
| | - Kenneth Prudence Abasubong
- Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, People's Republic of China
| | - Cong-Cong Wang
- Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, People's Republic of China
| | - Wen-Bin Liu
- Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, People's Republic of China.
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16
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Lee EJ, Chiang WCJ, Kroeger H, Bi CX, Chao DL, Skowronska-Krawczyk D, Mastey RR, Tsang SH, Chea L, Kim K, Lambert SR, Grandjean JM, Baumann B, Audo I, Kohl S, Moore AT, Wiseman RL, Carroll J, Lin JH. Multiexon deletion alleles of ATF6 linked to achromatopsia. JCI Insight 2020; 5:136041. [PMID: 32271167 PMCID: PMC7205249 DOI: 10.1172/jci.insight.136041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/04/2020] [Indexed: 12/20/2022] Open
Abstract
Achromatopsia (ACHM) is an autosomal recessive disease that results in severe visual loss. Symptoms of ACHM include impaired visual acuity, nystagmus, and photoaversion starting from infancy; furthermore, ACHM is associated with bilateral foveal hypoplasia and absent or severely reduced cone photoreceptor function on electroretinography. Here, we performed genetic sequencing in 3 patients from 2 families with ACHM, identifying and functionally characterizing 2 mutations in the activating transcription factor 6 (ATF6) gene. We identified a homozygous deletion covering exons 8-14 of the ATF6 gene from 2 siblings from the same family. In another patient from a different family, we identified a heterozygous deletion covering exons 2 and 3 of the ATF6 gene found in trans with a previously identified ATF6 c.970C>T (p.Arg324Cys) ACHM disease allele. Recombinant ATF6 proteins bearing these exon deletions showed markedly impaired transcriptional activity by qPCR and RNA-Seq analysis compared with WT-ATF6. Finally, RNAscope revealed that ATF6 and the related ATF6B transcripts were expressed in cones as well as in all retinal layers in normal human retina. Overall, our data identify loss-of-function ATF6 disease alleles that cause human foveal disease.
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Affiliation(s)
- Eun-Jin Lee
- Department of Ophthalmology, Shiley Eye Institute, and
- Department of Pathology, UCSD, San Diego, California, USA
- Department of Ophthalmology, Stanford University, Stanford, California, USA
| | - Wei-Chieh Jerry Chiang
- Department of Pathology, UCSD, San Diego, California, USA
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Heike Kroeger
- Department of Pathology, UCSD, San Diego, California, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | | | | | | | - Rebecca R. Mastey
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Stephen H. Tsang
- Departments of Ophthalmology and Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Leon Chea
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Kyle Kim
- Department of Pathology, UCSD, San Diego, California, USA
| | - Scott R. Lambert
- Department of Ophthalmology, Stanford University, Stanford, California, USA
| | - Julia M.D. Grandjean
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, California, USA
| | - Britta Baumann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC1423, Paris, France
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Anthony T. Moore
- Department of Ophthalmology, UCSF, San Francisco, California, USA
| | - R. Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, California, USA
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Jonathan H. Lin
- Department of Ophthalmology, Stanford University, Stanford, California, USA
- Department of Pathology, Stanford University, Stanford, California, USA
- VA Palo Alto Healthcare System, Palo Alto, California, USA
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17
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Sledgehammer to Scalpel: Broad Challenges to the Heart and Other Tissues Yield Specific Cellular Responses via Transcriptional Regulation of the ER-Stress Master Regulator ATF6α. Int J Mol Sci 2020; 21:ijms21031134. [PMID: 32046286 PMCID: PMC7037772 DOI: 10.3390/ijms21031134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 02/04/2020] [Accepted: 02/06/2020] [Indexed: 12/28/2022] Open
Abstract
There are more than 2000 transcription factors in eukaryotes, many of which are subject to complex mechanisms fine-tuning their activity and their transcriptional programs to meet the vast array of conditions under which cells must adapt to thrive and survive. For example, conditions that impair protein folding in the endoplasmic reticulum (ER), sometimes called ER stress, elicit the relocation of the ER-transmembrane protein, activating transcription factor 6α (ATF6α), to the Golgi, where it is proteolytically cleaved. This generates a fragment of ATF6α that translocates to the nucleus, where it regulates numerous genes that restore ER protein-folding capacity but is degraded soon after. Thus, upon ER stress, ATF6α is converted from a stable, transmembrane protein, to a rapidly degraded, nuclear protein that is a potent transcription factor. This review focuses on the molecular mechanisms governing ATF6α location, activity, and stability, as well as the transcriptional programs ATF6α regulates, whether canonical genes that restore ER protein-folding or unexpected, non-canonical genes affecting cellular functions beyond the ER. Moreover, we will review fascinating roles for an ATF6α isoform, ATF6β, which has a similar mode of activation but, unlike ATF6α, is a long-lived, weak transcription factor that may moderate the genetic effects of ATF6α.
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18
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Koba H, Jin S, Imada N, Ishikawa T, Ninagawa S, Okada T, Sakuma T, Yamamoto T, Mori K. Reinvestigation of Disulfide-bonded Oligomeric Forms of the Unfolded Protein Response Transducer ATF6. Cell Struct Funct 2020; 45:9-21. [PMID: 31852864 PMCID: PMC10739154 DOI: 10.1247/csf.19030] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/12/2019] [Indexed: 12/24/2023] Open
Abstract
ATF6α is an endoplasmic reticulum (ER)-embedded transcription factor which is rapidly activated by ER stress, and a major regulator of ER chaperone levels in vertebrates. We previously suggested that ATF6α occurs as a monomer, dimer and oligomer in the unstressed ER of Chinese hamster ovary cells due to the presence of two evolutionarily conserved cysteine residues in its luminal region (C467 and C618), and showed that ATF6α is reduced upon ER stress, such that only reduced monomer ATF6α is translocated to the Golgi apparatus for activation by proteolysis. However, mutagenesis analysis (C467A and C618A) revealed that the C618A mutant behaves in an unexpected manner (monomer and oligomer) during non-reducing SDS-PAGE, for reasons which remained unclear. Here, we used human colorectal carcinoma-derived HCT116 cells deficient in ATF6α and its relevant ATF6β, and found that ATF6α dimer and oligomer are both dimers, which we designated C618-dimer and C467-dimer, respectively. We demonstrated that C467-dimer (previously considered an oligomer) behaved bigger than C618-dimer (previously considered a dimer) during non-reducing SDS-PAGE, based on their disulfide-bonded structures. Furthermore, ATF6α monomer physically associates with another ATF6α monomer in the absence of disulfide bonding, which renders two C467 residues in close proximity so that formation of C467-dimer is much easier than that of C618-dimer. In contrast, C618-dimer is more easily reduced upon ER stress. Thus, our analysis revealed that all forms of ATF6α, namely monomer, C618-dimer and C467-dimer, are activated by single reduction of a disulfide bond in response to ER stress, ensuring the rapidity of ATF6α activation.Key words: disulfide-bonded structure, endoplasmic reticulum, membrane-bound transcription factor, non-reducing SDS-PAGE, unfolded protein response.
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Affiliation(s)
- Hibiki Koba
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Shengyu Jin
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Nanami Imada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Tokiro Ishikawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Satoshi Ninagawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Tetsuya Okada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Tetsushi Sakuma
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8526, Japan
| | - Takashi Yamamoto
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8526, Japan
| | - Kazutoshi Mori
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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19
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Johnston BP, McCormick C. Herpesviruses and the Unfolded Protein Response. Viruses 2019; 12:E17. [PMID: 31877732 PMCID: PMC7019427 DOI: 10.3390/v12010017] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/19/2019] [Accepted: 12/19/2019] [Indexed: 02/06/2023] Open
Abstract
Herpesviruses usurp cellular stress responses to promote viral replication and avoid immune surveillance. The unfolded protein response (UPR) is a conserved stress response that is activated when the protein load in the ER exceeds folding capacity and misfolded proteins accumulate. The UPR aims to restore protein homeostasis through translational and transcriptional reprogramming; if homeostasis cannot be restored, the UPR switches from "helper" to "executioner", triggering apoptosis. It is thought that the burst of herpesvirus glycoprotein synthesis during lytic replication causes ER stress, and that these viruses may have evolved mechanisms to manage UPR signaling to create an optimal niche for replication. The past decade has seen considerable progress in understanding how herpesviruses reprogram the UPR. Here we provide an overview of the molecular events of UPR activation, signaling and transcriptional outputs, and highlight key evidence that herpesviruses hijack the UPR to aid infection.
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Affiliation(s)
- Benjamin P. Johnston
- Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada;
- Beatrice Hunter Cancer Research Institute, 5850 College Street, Halifax, NS B3H 4R2, Canada
| | - Craig McCormick
- Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada;
- Beatrice Hunter Cancer Research Institute, 5850 College Street, Halifax, NS B3H 4R2, Canada
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20
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Karagöz GE, Acosta-Alvear D, Walter P. The Unfolded Protein Response: Detecting and Responding to Fluctuations in the Protein-Folding Capacity of the Endoplasmic Reticulum. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033886. [PMID: 30670466 DOI: 10.1101/cshperspect.a033886] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most of the secreted and plasma membrane proteins are synthesized on membrane-bound ribosomes on the endoplasmic reticulum (ER). They require engagement of ER-resident chaperones and foldases that assist in their folding and maturation. Since protein homeostasis in the ER is crucial for cellular function, the protein-folding status in the organelle's lumen is continually surveyed by a network of signaling pathways, collectively called the unfolded protein response (UPR). Protein-folding imbalances, or "ER stress," are detected by highly conserved sensors that adjust the ER's protein-folding capacity according to the physiological needs of the cell. We review recent developments in the field that have provided new insights into the ER stress-sensing mechanisms used by UPR sensors and the mechanisms by which they integrate various cellular inputs to adjust the folding capacity of the organelle to accommodate to fluctuations in ER protein-folding demands.
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Affiliation(s)
- G Elif Karagöz
- Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
| | - Diego Acosta-Alvear
- Department of Molecular, Cellular, and Developmental Biology, University of California at Santa Barbara, Santa Barbara, California 93106
| | - Peter Walter
- Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
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21
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Talty A, Deegan S, Ljujic M, Mnich K, Naicker SD, Quandt D, Zeng Q, Patterson JB, Gorman AM, Griffin MD, Samali A, Logue SE. Inhibition of IRE1α RNase activity reduces NLRP3 inflammasome assembly and processing of pro-IL1β. Cell Death Dis 2019; 10:622. [PMID: 31417078 PMCID: PMC6695440 DOI: 10.1038/s41419-019-1847-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 07/01/2019] [Accepted: 07/10/2019] [Indexed: 01/07/2023]
Abstract
The inflammasome is a multiprotein complex assembled in response to Pathogen Associated Molecular Patterns (PAMPs) and Danger Associated Molecular Patterns (DAMPs). Inflammasome activation occurs through a two-step mechanism, with the first signal facilitating priming of inflammasome components while the second signal triggers complex assembly. Once assembled, the inflammasome recruits and activates pro-caspase-1, which in turn processes pro-interleukin (IL)-18 and pro-IL-1β into their bio-active forms. Owing to its key role in the regulation of innate immune responses, the inflammasome has emerged as a therapeutic target for the treatment of inflammatory conditions. In this study we demonstrate that IRE1α, a key component of the Unfolded Protein Response, contributes to assembly of the NLRP3 inflammasome. Blockade of IRE1α RNase signaling lowered NLRP3 inflammasome assembly, caspase-1 activation and pro-IL-1β processing. These results underscore both the importance and potential therapeutic relevance of targeting IRE1α signaling in conditions of excessive inflammasome formation.
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Affiliation(s)
- Aaron Talty
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Shane Deegan
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Mila Ljujic
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Katarzyna Mnich
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Serika D Naicker
- Regenerative Medicine Institute (REMEDI) at CÚRAM Centre for Research in Medical Devices, School of Medicine, College of Medicine, Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - Dagmar Quandt
- Regenerative Medicine Institute (REMEDI) at CÚRAM Centre for Research in Medical Devices, School of Medicine, College of Medicine, Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland.,Institute of Anatomy and Cell Biology, Faculty of Medicine, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Qingping Zeng
- Fosun Orinove PharmaTech Inc., Suite 211, Building A4, 218 Xinghu St., Suzhou Industrial Park, 215123, Jiangsu, China
| | - John B Patterson
- Fosun Orinove PharmaTech Inc., 3537 Old Conejo Road, Suite 104, Newbury Park, CA, 91320, USA
| | - Adrienne M Gorman
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Matthew D Griffin
- Regenerative Medicine Institute (REMEDI) at CÚRAM Centre for Research in Medical Devices, School of Medicine, College of Medicine, Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - Afshin Samali
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Susan E Logue
- Apoptosis Research Centre, National University of Ireland Galway, Galway, Ireland. .,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland. .,Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada.
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22
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Oka OBV, van Lith M, Rudolf J, Tungkum W, Pringle MA, Bulleid NJ. ERp18 regulates activation of ATF6α during unfolded protein response. EMBO J 2019; 38:e100990. [PMID: 31368601 PMCID: PMC6670016 DOI: 10.15252/embj.2018100990] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 05/03/2019] [Accepted: 05/20/2019] [Indexed: 01/08/2023] Open
Abstract
Activation of the ATF6α signaling pathway is initiated by trafficking of ATF6α from the ER to the Golgi apparatus. Its subsequent proteolysis releases a transcription factor that translocates to the nucleus causing downstream gene activation. How ER retention, Golgi trafficking, and proteolysis of ATF6α are regulated and whether additional protein partners are required for its localization and processing remain unresolved. Here, we show that ER-resident oxidoreductase ERp18 associates with ATF6α following ER stress and plays a key role in both trafficking and activation of ATF6α. We find that ERp18 depletion attenuates the ATF6α stress response. Paradoxically, ER stress accelerates trafficking of ATF6α to the Golgi in ERp18-depleted cells. However, the translocated ATF6α becomes aberrantly processed preventing release of the soluble transcription factor. Hence, we demonstrate that ERp18 monitors ATF6α ER quality control to ensure optimal processing following trafficking to the Golgi.
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Affiliation(s)
- Ojore BV Oka
- Institute of Molecular, Cell and Systems BiologyCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Marcel van Lith
- Institute of Molecular, Cell and Systems BiologyCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Jana Rudolf
- Inserm U1035/BMGICUniversity of BordeauxBordeauxFrance
| | - Wanida Tungkum
- Institute of Molecular, Cell and Systems BiologyCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Marie Anne Pringle
- Institute of Molecular, Cell and Systems BiologyCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Neil J Bulleid
- Institute of Molecular, Cell and Systems BiologyCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
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23
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Ismail NI, Othman I, Abas F, H Lajis N, Naidu R. Mechanism of Apoptosis Induced by Curcumin in Colorectal Cancer. Int J Mol Sci 2019; 20:E2454. [PMID: 31108984 PMCID: PMC6566943 DOI: 10.3390/ijms20102454] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 04/20/2019] [Accepted: 04/26/2019] [Indexed: 02/07/2023] Open
Abstract
Colorectal cancer (CRC) is among the top three cancer with higher incident and mortality rate worldwide. It is estimated that about over than 1.1 million of death and 2.2 million new cases by the year 2030. The current treatment modalities with the usage of chemo drugs such as FOLFOX and FOLFIRI, surgery and radiotherapy, which are usually accompanied with major side effects, are rarely cured along with poor survival rate and at higher recurrence outcome. This trigger the needs of exploring new natural compounds with anti-cancer properties which possess fewer side effects. Curcumin, a common spice used in ancient medicine was found to induce apoptosis by targeting various molecules and signaling pathways involved in CRC. Disruption of the homeostatic balance between cell proliferation and apoptosis could be one of the promoting factors in colorectal cancer progression. In this review, we describe the current knowledge of apoptosis regulation by curcumin in CRC with regard to molecular targets and associated signaling pathways.
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Affiliation(s)
- Nor Isnida Ismail
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway Darul Ehsan, Malaysia.
- UniKL MESTECH, A1-1 Jalan TKS1, Taman Kajang Sentral, 43000 Kajang, Malaysia.
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway Darul Ehsan, Malaysia.
| | - Faridah Abas
- Laboratory of Natural Products, Faculty of Science, University Putra Malaysia, UPM, 43400 Serdang, Malaysia.
- Department of Food Science, Faculty of Food Science and Technology, University Putra Malaysia, UPM, 434000 Serdang, Malaysia.
| | - Nordin H Lajis
- Laboratory of Natural Products, Faculty of Science, University Putra Malaysia, UPM, 43400 Serdang, Malaysia.
| | - Rakesh Naidu
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway Darul Ehsan, Malaysia.
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24
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Glembotski CC, Rosarda JD, Wiseman RL. Proteostasis and Beyond: ATF6 in Ischemic Disease. Trends Mol Med 2019; 25:538-550. [PMID: 31078432 DOI: 10.1016/j.molmed.2019.03.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/16/2019] [Accepted: 03/25/2019] [Indexed: 12/28/2022]
Abstract
Endoplasmic reticulum (ER) stress is a pathological hallmark of numerous ischemic diseases, including stroke and myocardial infarction (MI). In these diseases, ER stress leads to activation of the unfolded protein response (UPR) and subsequent adaptation of cellular physiology in ways that dictate cellular fate following ischemia. Recent evidence highlights a protective role for the activating transcription factor 6 (ATF6) arm of the UPR in mitigating adverse outcomes associated with ischemia/reperfusion (I/R) injury in multiple disease models. This suggests ATF6 as a potential therapeutic target for intervening in diverse ischemia-related disorders. Here, we discuss the evidence demonstrating the importance of ATF6 signaling in protecting different tissues against ischemic damage and discuss preclinical results focused on defining the potential for pharmacologically targeting ATF6 to intervene in such diseases.
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Affiliation(s)
- Christopher C Glembotski
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Jessica D Rosarda
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
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25
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Emerging Roles of the Endoplasmic Reticulum Associated Unfolded Protein Response in Cancer Cell Migration and Invasion. Cancers (Basel) 2019; 11:cancers11050631. [PMID: 31064137 PMCID: PMC6562633 DOI: 10.3390/cancers11050631] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 12/21/2022] Open
Abstract
Endoplasmic reticulum (ER) proteostasis is often altered in tumor cells due to intrinsic (oncogene expression, aneuploidy) and extrinsic (environmental) challenges. ER stress triggers the activation of an adaptive response named the Unfolded Protein Response (UPR), leading to protein translation repression, and to the improvement of ER protein folding and clearance capacity. The UPR is emerging as a key player in malignant transformation and tumor growth, impacting on most hallmarks of cancer. As such, the UPR can influence cancer cells’ migration and invasion properties. In this review, we overview the involvement of the UPR in cancer progression. We discuss its cross-talks with the cell migration and invasion machinery. Specific aspects will be covered including extracellular matrix (ECM) remodeling, modification of cell adhesion, chemo-attraction, epithelial-mesenchymal transition (EMT), modulation of signaling pathways associated with cell mobility, and cytoskeleton remodeling. The therapeutic potential of targeting the UPR to treat cancer will also be considered with specific emphasis in the impact on metastasis and tissue invasion.
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26
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Shakib N, Khadem Ansari MH, Karimi P, Rasmi Y. Neuroprotective mechanism of low-dose sodium nitrite in oxygen-glucose deprivation model of cerebral ischemic stroke in PC12 cells. EXCLI JOURNAL 2019; 18:229-242. [PMID: 31217786 PMCID: PMC6558507 DOI: 10.17179/excli2018-1947] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/26/2019] [Indexed: 01/29/2023]
Abstract
The purpose of this study was to clarify the mechanisms of the protective effects of low-dose sodium nitrite (SN) on oxygen and glucose deprivation (OGD)-induced endoplasmic reticulum (ER) stress in PC12 cells. The PC12 cells were exposed to 4 h of OGD and treated with 100 μmol SN. The expression and activity of ER stress markers, including PKR-like endoplasmic reticulum kinase (PERK), transcription factor 6 (ATF6), CCAAT/enhancer binding protein homologous protein (CHOP), as well as caspase-12 and -3, were detected by immunoblotting assay. Fluorescence staining was used to detect the levels of reactive oxygen species (ROS) and Ca2+ release from the ER. Cell viability was also evaluated by MTT assay. It was found that SN significantly inhibited ROS production and Ca2+ release from the ER in OGD-injured PC12 cells. Moreover, ER stress marker expression and cleaved fragments of caspase-3 and -12 in OGD-injured PC12 cells were decreased after SN treatment. These findings were accompanied by a significant increase in cell viability. It seems that SN exerts a neuroprotective effect at least partially through reduction of ROS-mediated ER stress caused by OGD insult.
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Affiliation(s)
- Nader Shakib
- Department of Biochemistry, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | | | - Pouran Karimi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yousef Rasmi
- Department of Biochemistry, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
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27
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Abstract
Eukaryotic cells respond to an overload of unfolded proteins in the endoplasmic reticulum (ER) by activating signaling pathways that are referred to as the unfolded protein response (UPR). Much UPR research has been conducted in cultured cells that exhibit no baseline UPR activity until they are challenged by ER stress initiated by chemicals or mutant proteins. At the same time, many genes that mediate UPR signaling are essential for the development of organisms ranging from Drosophila and fish to mice and humans, indicating that there is physiological ER stress that requires UPR in normally developing animal tissues. Recent studies have elucidated the tissue-specific roles of all three branches of UPR in distinct developing tissues of Drosophila, fish and mammals. As discussed in this Review, these studies not only reveal the physiological functions of the UPR pathways but also highlight a surprising degree of specificity associated with each UPR branch in development.
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Affiliation(s)
- Sahana Mitra
- Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Hyung Don Ryoo
- Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
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28
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Correll RN, Grimes KM, Prasad V, Lynch JM, Khalil H, Molkentin JD. Overlapping and differential functions of ATF6α versus ATF6β in the mouse heart. Sci Rep 2019; 9:2059. [PMID: 30765833 PMCID: PMC6375966 DOI: 10.1038/s41598-019-39515-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/02/2019] [Indexed: 01/22/2023] Open
Abstract
Hemodynamic stress on the mammalian heart results in compensatory hypertrophy and activation of the unfolded protein response through activating transcription factor 6α (ATF6α) in cardiac myocytes, but the roles of ATF6α or the related transcription factor ATF6β in regulating this hypertrophic response are not well-understood. Here we examined the effects of loss of ATF6α or ATF6β on the cardiac response to pressure overload. Mice gene-deleted for Atf6 or Atf6b were subjected to 2 weeks of transverse aortic constriction, and each showed a significant reduction in hypertrophy with reduced expression of endoplasmic reticulum (ER) stress-associated proteins compared with controls. However, with long-term pressure overload both Atf6 and Atf6b null mice showed enhanced decompensation typified by increased heart weight, pulmonary edema and reduced function compared to control mice. Our subsequent studies using cardiac-specific transgenic mice expressing the transcriptionally active N-terminus of ATF6α or ATF6β revealed that these factors control overlapping gene expression networks that include numerous ER protein chaperones and ER associated degradation components. This work reveals previously unappreciated roles for ATF6α and ATF6β in regulating the pressure overload induced cardiac hypertrophic response and in controlling the expression of genes that condition the ER during hemodynamic stress.
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Affiliation(s)
- Robert N Correll
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, 35487, USA.,Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229, USA
| | - Kelly M Grimes
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229, USA
| | - Vikram Prasad
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229, USA
| | - Jeffrey M Lynch
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229, USA
| | - Hadi Khalil
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229, USA
| | - Jeffery D Molkentin
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45229, USA. .,Howard Hughes Medical Institute, Cincinnati, Ohio, 45229, USA.
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29
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Naturally Occurring Hepatitis B Virus Mutations Leading to Endoplasmic Reticulum Stress and Their Contribution to the Progression of Hepatocellular Carcinoma. Int J Mol Sci 2019; 20:ijms20030597. [PMID: 30704071 PMCID: PMC6387469 DOI: 10.3390/ijms20030597] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 02/07/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a global health problem that causes a wide range of pathological outcomes, including cirrhosis and hepatocellular carcinoma (HCC). Endoplasmic reticulum (ER) stress induction by HBV infection has been implicated in liver carcinogenesis and disease progression with chronic inflammation via enhanced inflammation, oxidative stress-mediated DNA damage, and hepatocyte proliferation. In the natural course of HBV infection, the accumulation of naturally occurring mutations in the HBV genome can generate several mutant types of HBV-encoded proteins, including three different proteins in the S ORF (SHBs, MHBs, and LHBs) and HBcAg in the C ORF, which could contribute to enhanced ER stress in infected hepatocytes mainly via increased ER accumulation of mutant proteins. However, it seems that there may be distinct capacity and pathway in ER stress-induction and distinct resulting clinical outcomes between HBV variants. In addition, the role of HBxAg mutations in ER stress remains unknown. However, it has been reported that HBxAg itself could exert ER stress in infected cells, resulting in HCC generation in chronic HBV patients. To date, review papers regarding ER stress-mediated HBV mutation have been limited into a specific mutation type: preS2 deletion. So, in this review, we will discuss details about various mutation types in all four regions of the HBV genome (preS1, preS2, S, and C) related to ER stress and their distinct ER stress mechanisms and clinical outcomes in terms of mutation types.
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30
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Forouhan M, Mori K, Boot-Handford RP. Paradoxical roles of ATF6α and ATF6β in modulating disease severity caused by mutations in collagen X. Matrix Biol 2018; 70:50-71. [PMID: 29522813 PMCID: PMC6090092 DOI: 10.1016/j.matbio.2018.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/02/2018] [Accepted: 03/03/2018] [Indexed: 01/05/2023]
Abstract
Whilst the role of ATF6α in modulating the unfolded protein response (UPR) has been well documented, the function of its paralogue ATF6β is less well understood. Using knockdown in cell culture and gene ablation in mice we have directly compared the roles of ATF6α & β in responding to the increased ER stress induced by mutant forms of type X collagen that cause the ER stress-associated metaphyseal chondrodysplasia type Schmid (MCDS). ATF6α more efficiently deals with the disease-associated ER stress in the absence of ATF6β and conversely, ATF6β is less effective in the absence of ATF6α. Furthermore, disease severity in vivo is increased by ATF6α ablation and decreased by ATF6β ablation. In addition, novel functions for each paralogue are described including an ATF6β-specific role in controlling growth plate chondrocyte proliferation. The clear demonstration of the intimate relationship of the two ATF6 isoforms and how ATF6β can moderate the activity of ATF6α and vice versa is of great significance for understanding the UPR mechanism. The activities of both ATF6 isoforms and their separate roles need consideration when deciding how to target increased ER stress as a means of treating MCDS and other ER stress-associated diseases.
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Affiliation(s)
- M Forouhan
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Manchester, UK
| | - K Mori
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - R P Boot-Handford
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Manchester, UK.
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31
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LoPresti P. Tau in Oligodendrocytes Takes Neurons in Sickness and in Health. Int J Mol Sci 2018; 19:ijms19082408. [PMID: 30111714 PMCID: PMC6121290 DOI: 10.3390/ijms19082408] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/05/2018] [Accepted: 08/06/2018] [Indexed: 12/31/2022] Open
Abstract
Oligodendrocytes (OLGs), the myelin-forming cells of the central nervous system (CNS), are lifelong partners of neurons. They adjust to the functional demands of neurons over the course of a lifetime to meet the functional needs of a healthy CNS. When this functional interplay breaks down, CNS degeneration follows. OLG processes are essential features for OLGs being able to connect with the neurons. As many as fifty cellular processes from a single OLG reach and wrap an equal number of axonal segments. The cellular processes extend to meet and wrap axonal segments with myelin. Further, transport regulation, which is critical for myelination, takes place within the cellular processes. Because the microtubule-associated protein tau plays a crucial role in cellular process extension and myelination, alterations of tau in OLGs have deleterious effects, resulting in neuronal malfunction and CNS degeneration. Here, we review current concepts on the lifelong role of OLGs and myelin for brain health and plasticity. We present key studies of tau in OLGs and select important studies of tau in neurons. The extensive work on tau in neurons has considerably advanced our understanding of how tau promotes either health or disease. Because OLGs are crucial to neuronal health at any age, an understanding of the functions and regulation of tau in OLGs could uncover new therapeutics for selective CNS neurodegenerative diseases.
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Affiliation(s)
- Patrizia LoPresti
- Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607, USA.
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32
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Li XM, Liu J, Pan FF, Shi DD, Wen ZG, Yang PL. Quercetin and aconitine synergistically induces the human cervical carcinoma HeLa cell apoptosis via endoplasmic reticulum (ER) stress pathway. PLoS One 2018; 13:e0191062. [PMID: 29324796 PMCID: PMC5764366 DOI: 10.1371/journal.pone.0191062] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/26/2017] [Indexed: 12/28/2022] Open
Abstract
Up till now, studies have not been conducted on how the combination of Quercetin (Q), Aconitine (A) and apoptosis induction affects human cervical carcinoma HeLa cells. The result of our findings shows that the combination of Q and A (QA) is capable of synergistically inhibiting the proliferation of HeLa cells in a number of concentrations. QA synergistically inhibits the proliferation of MDR1 gene in the HeLa cells. It is concluded based on our result that QA induces apoptosis and ER stress just as QA-induced ER stress pathway may mediate apoptosis by upregulating mRNA expression levels of eIF2α, ATF4, IRE1, XBP1, ATF6, PERK and CHOP in the HeLa cells. The up-regulating of mRNA expression level of GRP78 and activation of UPR are a molecular basis of QA-induced ER stress.
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Affiliation(s)
- Xiu-Mei Li
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jing Liu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fang-Fang Pan
- Key Lab of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Dong-Dong Shi
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhi-Guo Wen
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Pei-Long Yang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
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33
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Sodium fluoride (NaF) induces the splenic apoptosis via endoplasmic reticulum (ER) stress pathway in vivo and in vitro. Aging (Albany NY) 2017; 8:3552-3567. [PMID: 28039491 PMCID: PMC5270686 DOI: 10.18632/aging.101150] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 12/20/2016] [Indexed: 02/06/2023]
Abstract
At present, there are no reports on the relationship between fluoride-induced apoptosis and endoplasmic reticulum (ER) stress (ER stress) in the spleen of human and animals in vivo and in vitro. Therefore, the aim of this study was to define sodium fluoride (NaF)-induced apoptosis mediated by ER stress in the spleen of mice in vivo and in vitro. Apoptosis and expression levels of the ER stress-related proteins were detected by flow cytometry and western blot, respectively. The results showed that NaF treatment increased lymphocytes apoptosis, which was consistent with NaF-caused ER Stress. NaF-caused ER stress was characterized by up-regulating protein expression levels of glucose-regulated protein 78 (BiP) and glucose-regulated protein 94 (GRP94), and by activating unfolded protein response (UPR). The signaling pathway of ER stress-associated apoptosis was activated by up-regulating protein expression levels of cleaved cysteine aspartate specific protease-12 (cleaved caspase-12), growth arrest and DNA damage-inducible gene 153 (Gadd153/CHOP) and phosphorylation of JUN N-terminal kinase (p-JNK). Additionally, our in vitro study found that apoptotic rate was decreased with remarkable down-regulation of the cleaved caspase-12, CHOP, p-JNK after ER stress was inhibited by 4-Phenylbutyric acid (4-PBA) treatment. In conclusion, NaF-induced apoptosis may mediated by ER stress in the spleen.
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34
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Niu M, Dai X, Zou W, Yu X, Teng W, Chen Q, Sun X, Yu W, Ma H, Liu P. Autophagy, Endoplasmic Reticulum Stress and the Unfolded Protein Response in Intracerebral Hemorrhage. Transl Neurosci 2017; 8:37-48. [PMID: 28729917 PMCID: PMC5444040 DOI: 10.1515/tnsci-2017-0008] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/22/2017] [Indexed: 12/11/2022] Open
Abstract
Intracerebral hemorrhage (ICH) is a subtype of stroke that is followed by primary and secondary brain injury. As a result of the injury, cell metabolism is disrupted and a series of stress responses are activated, such as endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), leading to the re-establishment of cell homeostasis or cell death. As an important mechanism of cell homeostasis, autophagy has been widely studied, and the associations between autophagy, ER stress, and the UPR have also been demonstrated. Whether these mechanisms are beneficial or detrimental remains a matter of controversy, but there is no doubt as to their vital functions. An understanding of the mechanisms of injury and recovery after ICH is crucial to develop therapeutic strategies. In this review, we summarize the related studies and highlight the roles of autophagy, ER stress, and the UPR in disease, especially in ICH. We also provide an overview of therapeutic approaches that target autophagy, and we discuss the prospects for modulating autophagy, ER stress, and UPR mechanisms in ICH therapy.
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Affiliation(s)
- Mingming Niu
- Department of Clinical Medicine, Heilongjiang University of Chinese Medicine, 24 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Xiaohong Dai
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Wei Zou
- Department of Clinical Medicine, Heilongjiang University of Chinese Medicine, 24 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Xueping Yu
- Department of Clinical Medicine, Heilongjiang University of Chinese Medicine, 24 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Wei Teng
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Qiuxin Chen
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Xiaowei Sun
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Weiwei Yu
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Huihui Ma
- Department of Neurology, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, 26 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
| | - Peng Liu
- Department of Clinical Medicine, Heilongjiang University of Chinese Medicine, 24 Heping Road, Harbin, Heilongjiang, 150040, P. R.China
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35
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Ariyasu D, Yoshida H, Hasegawa Y. Endoplasmic Reticulum (ER) Stress and Endocrine Disorders. Int J Mol Sci 2017; 18:ijms18020382. [PMID: 28208663 PMCID: PMC5343917 DOI: 10.3390/ijms18020382] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/24/2017] [Accepted: 02/03/2017] [Indexed: 12/15/2022] Open
Abstract
The endoplasmic reticulum (ER) is the organelle where secretory and membrane proteins are synthesized and folded. Unfolded proteins that are retained within the ER can cause ER stress. Eukaryotic cells have a defense system called the “unfolded protein response” (UPR), which protects cells from ER stress. Cells undergo apoptosis when ER stress exceeds the capacity of the UPR, which has been revealed to cause human diseases. Although neurodegenerative diseases are well-known ER stress-related diseases, it has been discovered that endocrine diseases are also related to ER stress. In this review, we focus on ER stress-related human endocrine disorders. In addition to diabetes mellitus, which is well characterized, several relatively rare genetic disorders such as familial neurohypophyseal diabetes insipidus (FNDI), Wolfram syndrome, and isolated growth hormone deficiency type II (IGHD2) are discussed in this article.
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Affiliation(s)
- Daisuke Ariyasu
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Hiderou Yoshida
- Department of Biochemistry and Molecular Biology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan.
| | - Yukihiro Hasegawa
- Division of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo 183-8561, Japan.
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36
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Gallagher CM, Garri C, Cain EL, Ang KKH, Wilson CG, Chen S, Hearn BR, Jaishankar P, Aranda-Diaz A, Arkin MR, Renslo AR, Walter P. Ceapins are a new class of unfolded protein response inhibitors, selectively targeting the ATF6α branch. eLife 2016; 5. [PMID: 27435960 PMCID: PMC4954757 DOI: 10.7554/elife.11878] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 05/26/2016] [Indexed: 12/14/2022] Open
Abstract
The membrane-bound transcription factor ATF6α plays a cytoprotective role in the unfolded protein response (UPR), required for cells to survive ER stress. Activation of ATF6α promotes cell survival in cancer models. We used cell-based screens to discover and develop Ceapins, a class of pyrazole amides, that block ATF6α signaling in response to ER stress. Ceapins sensitize cells to ER stress without impacting viability of unstressed cells. Ceapins are highly specific inhibitors of ATF6α signaling, not affecting signaling through the other branches of the UPR, or proteolytic processing of its close homolog ATF6β or SREBP (a cholesterol-regulated transcription factor), both activated by the same proteases. Ceapins are first-in-class inhibitors that can be used to explore both the mechanism of activation of ATF6α and its role in pathological settings. The discovery of Ceapins now enables pharmacological modulation all three UPR branches either singly or in combination. DOI:http://dx.doi.org/10.7554/eLife.11878.001 Newly made proteins must be folded into specific three-dimensional shapes before they can perform their roles in cells. Many proteins are folded in a cell compartment called the endoplasmic reticulum. The cell closely monitors the quality of the work done by this compartment. If the endoplasmic reticulum has more proteins to fold than it can handle, unfolded or misfolded proteins accumulate and trigger a stress response called the unfolded protein response. This increases the capacity of the endoplasmic reticulum to fold proteins to match the demand. However, if the stress persists, then the unfolded protein response instructs the cell to die to protect the rest of the body. A protein called ATF6α is one of three branches of the unfolded protein response. This protein is found in the endoplasmic reticulum where it is inactive. Endoplasmic stress causes ATF6α to move from the endoplasmic reticulum to another compartment called the Golgi apparatus. There, two enzymes cut ATF6α to release a fragment of the protein that then moves to the nucleus to increase the production of the machinery needed to fold proteins in the endoplasmic reticulum. Errors in protein folding can cause serious diseases in humans and other animals. Drugs that target ATF6α might be able to regulate part of the unfolded protein response to treat these diseases. However, no drugs that act on ATF6α had been identified. Now, two groups of researchers have independently identified small molecules that specifically target ATF6α. Gallagher et al. screened over 100,000 compounds for their ability to reduce the activity of ATF6α-regulated genes. The experiments reveal that a class of small molecules termed Ceapins can selectively block the activity of ATF6α during endoplasmic reticulum stress, but had no effect on other proteins involved in the unfolded protein response. Furthermore, when human cells experiencing stress were treated with Ceapins, a greater number of cells died in comparison to cells that had not received Ceapins. An accompanying study by Gallagher and Walter reports on the mechanism by which Ceapins act on ATF6α. Independently, Plate et al. identified a type of small molecule that can activate ATF6. Together, the findings of Gallagher et al. and Plate et al. may lead to the development of new drugs for treating diseases associated with incorrect protein folding in the endoplasmic reticulum. DOI:http://dx.doi.org/10.7554/eLife.11878.002
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Affiliation(s)
- Ciara M Gallagher
- Department of Biochemistry and Biophysics, Howard Hughes MedicaI Institute, University of California, San Francisco, United States
| | - Carolina Garri
- Department of Biochemistry and Biophysics, Howard Hughes MedicaI Institute, University of California, San Francisco, United States.,Fundación Ciencia Para la Vida, Santiago, Chile
| | - Erica L Cain
- Department of Biochemistry and Biophysics, Howard Hughes MedicaI Institute, University of California, San Francisco, United States
| | - Kenny Kean-Hooi Ang
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Christopher G Wilson
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Steven Chen
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Brian R Hearn
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Priyadarshini Jaishankar
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Andres Aranda-Diaz
- Department of Biochemistry and Biophysics, Howard Hughes MedicaI Institute, University of California, San Francisco, United States
| | - Michelle R Arkin
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Adam R Renslo
- Small Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Peter Walter
- Department of Biochemistry and Biophysics, Howard Hughes MedicaI Institute, University of California, San Francisco, United States
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37
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Gallagher CM, Walter P. Ceapins inhibit ATF6α signaling by selectively preventing transport of ATF6α to the Golgi apparatus during ER stress. eLife 2016; 5. [PMID: 27435962 PMCID: PMC4954756 DOI: 10.7554/elife.11880] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 05/22/2016] [Indexed: 02/07/2023] Open
Abstract
The membrane-bound transcription factor ATF6α is activated by proteolysis during endoplasmic reticulum (ER) stress. ATF6α target genes encode foldases, chaperones, and lipid biosynthesis enzymes that increase protein-folding capacity in response to demand. The off-state of ATF6α is maintained by its spatial separation in the ER from Golgi-resident proteases that activate it. ER stress induces trafficking of ATF6α. We discovered Ceapins, a class of pyrazole amides, as selective inhibitors of ATF6α signaling that do not inhibit the Golgi proteases or other UPR branches. We show that Ceapins block ATF6α signaling by trapping it in ER-resident foci that are excluded from ER exit sites. Removing the requirement for trafficking by pharmacological elimination of the spatial separation of the ER and Golgi apparatus restored cleavage of ATF6α in the presence of Ceapins. Washout of Ceapins resensitized ATF6α to ER stress. These results suggest that trafficking of ATF6α is regulated by its oligomeric state. DOI:http://dx.doi.org/10.7554/eLife.11880.001 Newly made proteins must be folded into specific three-dimensional shapes before they can perform their roles in cells. Many proteins are folded in a cell compartment called the endoplasmic reticulum. The cell closely monitors the quality of the work done by this compartment. If the endoplasmic reticulum has more proteins to fold than it can handle, unfolded or misfolded proteins accumulate and trigger a stress response called the unfolded protein response. This increases the capacity of the endoplasmic reticulum to fold proteins to match the demand. However, if the stress persists, then the unfolded protein response instructs the cell to die to protect the rest of the body. A protein called ATF6α is one of three branches of the unfolded protein response. This protein is found in the endoplasmic reticulum where it is inactive. Endoplasmic stress causes ATF6α to move from the endoplasmic reticulum to another compartment called the Golgi apparatus. There, two enzymes cut ATF6α to release a fragment of the protein that then moves to the nucleus to increase the production of the machinery needed to fold proteins in the endoplasmic reticulum. In a related study, Gallagher et al. identified a group of small molecules called Ceapins, which inhibit ATF6α activity. Here, Gallagher and Walter investigate how Ceapins act on ATF6α. The experiments show that Ceapin causes ATF6α molecules to form clusters that prevent the protein from moving to the Golgi apparatus by keeping it away from the machinery that moves proteins between these compartments. When the enzymes that cut ATF6α are sent to the endoplasmic reticulum, Ceapin treatment no longer prevents ATF6α activation, which shows that these small molecules specifically inhibit the stress-induced movement of ATF6α. When Ceapins are washed out of cells, the ATF6α clusters fall apart and ATF6α can now move to the Golgi. These experiments show that ATF6α is actively held in the endoplasmic reticulum by a mechanism that is stabilized by Ceapins. Gallagher and Walter propose that the small clusters of ATF6α in unstressed cells act to keep this protein in the endoplasmic reticulum. However, when cells experience stress, the ATF6α clusters fall apart to allow the protein to move to the Golgi. The next steps following on from this work are to find out what these clusters are, how they are influenced by endoplasmic reticulum stress and exactly how the Ceapins stabilize these clusters. DOI:http://dx.doi.org/10.7554/eLife.11880.002
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Affiliation(s)
- Ciara M Gallagher
- Howard Hughes MedicaI Institute, University of California, San Francisco, San Francisco, United States.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Peter Walter
- Howard Hughes MedicaI Institute, University of California, San Francisco, San Francisco, United States.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
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38
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Liu MQ, Chen Z, Chen LX. Endoplasmic reticulum stress: a novel mechanism and therapeutic target for cardiovascular diseases. Acta Pharmacol Sin 2016; 37:425-43. [PMID: 26838072 DOI: 10.1038/aps.2015.145] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/23/2015] [Indexed: 12/13/2022] Open
Abstract
Endoplasmic reticulum is a principal organelle responsible for folding, post-translational modifications and transport of secretory, luminal and membrane proteins, thus palys an important rale in maintaining cellular homeostasis. Endoplasmic reticulum stress (ERS) is a condition that is accelerated by accumulation of unfolded/misfolded proteins after endoplasmic reticulum environment disturbance, triggered by a variety of physiological and pathological factors, such as nutrient deprivation, altered glycosylation, calcium depletion, oxidative stress, DNA damage and energy disturbance, etc. ERS may initiate the unfolded protein response (UPR) to restore cellular homeostasis or lead to apoptosis. Numerous studies have clarified the link between ERS and cardiovascular diseases. This review focuses on ERS-associated molecular mechanisms that participate in physiological and pathophysiological processes of heart and blood vessels. In addition, a number of drugs that regulate ERS was introduced, which may be used to treat cardiovascular diseases. This review may open new avenues for studying the pathogenesis of cardiovascular diseases and discovering novel drugs targeting ERS.
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39
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Kohl S, Zobor D, Chiang WC, Weisschuh N, Staller J, Gonzalez Menendez I, Chang S, Beck SC, Garcia Garrido M, Sothilingam V, Seeliger MW, Stanzial F, Benedicenti F, Inzana F, Héon E, Vincent A, Beis J, Strom TM, Rudolph G, Roosing S, Hollander AID, Cremers FPM, Lopez I, Ren H, Moore AT, Webster AR, Michaelides M, Koenekoop RK, Zrenner E, Kaufman RJ, Tsang SH, Wissinger B, Lin JH. Mutations in the unfolded protein response regulator ATF6 cause the cone dysfunction disorder achromatopsia. Nat Genet 2015; 47:757-65. [PMID: 26029869 DOI: 10.1038/ng.3319] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 05/04/2015] [Indexed: 01/10/2023]
Abstract
Achromatopsia (ACHM) is an autosomal recessive disorder characterized by color blindness, photophobia, nystagmus and severely reduced visual acuity. Using homozygosity mapping and whole-exome and candidate gene sequencing, we identified ten families carrying six homozygous and two compound-heterozygous mutations in the ATF6 gene (encoding activating transcription factor 6A), a key regulator of the unfolded protein response (UPR) and cellular endoplasmic reticulum (ER) homeostasis. Patients had evidence of foveal hypoplasia and disruption of the cone photoreceptor layer. The ACHM-associated ATF6 mutations attenuate ATF6 transcriptional activity in response to ER stress. Atf6(-/-) mice have normal retinal morphology and function at a young age but develop rod and cone dysfunction with increasing age. This new ACHM-related gene suggests a crucial and unexpected role for ATF6A in human foveal development and cone function and adds to the list of genes that, despite ubiquitous expression, when mutated can result in an isolated retinal photoreceptor phenotype.
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Affiliation(s)
- Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Ditta Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Wei-Chieh Chiang
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
| | - Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Jennifer Staller
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Irene Gonzalez Menendez
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Stanley Chang
- 1] Department of Ophthalmology, Columbia University, New York, New York, USA. [2] Edward Harkness Eye Institute, New York Presbyterian Hospital, New York, New York, USA
| | - Susanne C Beck
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Marina Garcia Garrido
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Vithiyanjali Sothilingam
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Mathias W Seeliger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Franco Stanzial
- Clinical Genetics Service, Regional Hospital Bozen, Bozen, Italy
| | | | - Francesca Inzana
- Clinical Genetics Service, Regional Hospital Bozen, Bozen, Italy
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, Programme of Genetics and Genomic Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, Programme of Genetics and Genomic Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Jill Beis
- Medical Genetics, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Tim M Strom
- 1] Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany. [2] Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Günther Rudolph
- University Eye Hospital, Ludwig Maximilians University, Munich, Germany
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Anneke I den Hollander
- 1] Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands. [2] Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Irma Lopez
- McGill Ocular Genetics Centre, McGill University Health Centre, Montreal, Quebec, Canada
| | - Huanan Ren
- McGill Ocular Genetics Centre, McGill University Health Centre, Montreal, Quebec, Canada
| | - Anthony T Moore
- 1] University College London Institute of Ophthalmology, University College London, London, UK. [2] Moorfields Eye Hospital, London, UK. [3] Ophthalmology Department, University of California San Francisco Medical School, San Francisco, California, USA
| | - Andrew R Webster
- 1] University College London Institute of Ophthalmology, University College London, London, UK. [2] Moorfields Eye Hospital, London, UK
| | - Michel Michaelides
- 1] University College London Institute of Ophthalmology, University College London, London, UK. [2] Moorfields Eye Hospital, London, UK
| | - Robert K Koenekoop
- McGill Ocular Genetics Centre, McGill University Health Centre, Montreal, Quebec, Canada
| | - Eberhart Zrenner
- 1] Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany. [2] Werner Reichardt Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - Stephen H Tsang
- 1] Department of Ophthalmology, Columbia University, New York, New York, USA. [2] Jonas Laboratory of Stem Cell and Regenerative Medicine, Columbia University, New York, New York, USA. [3] Brown Glaucoma Laboratory, Columbia University, New York, New York, USA. [4] Institute of Human Nutrition, Columbia University, New York, New York, USA. [5] Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Jonathan H Lin
- 1] Department of Pathology, University of California, San Diego, La Jolla, California, USA. [2] Department of Ophthalmology, University of California, San Diego, La Jolla, California, USA
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Maeda T, Suzuki A, Yuzawa S, Baba Y, Kimura Y, Kato Y. Mineral trioxide aggregate induces osteoblastogenesis via Atf6. Bone Rep 2015; 2:36-43. [PMID: 28377952 PMCID: PMC5365173 DOI: 10.1016/j.bonr.2015.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/26/2015] [Indexed: 12/27/2022] Open
Abstract
Mineral trioxide aggregate (MTA) has been recommended for various uses in endodontics. To understand the effects of MTA on alveolar bone, we examined whether MTA induces osteoblastic differentiation using MC3T3-E1 cells. MTA enhanced mineralization concomitant with alkaline phosphatase activity in a dose- and time-dependent manner. MTA increased production of collagens (Type I and Type III) and matrix metalloproteinases (MMP-9 and MMP-13), suggesting that MTA affects bone matrix remodeling. MTA also induced Bglap (osteocalcin) but not Bmp2 (bone morphogenetic protein-2) mRNA expression. We observed induction of Atf6 (activating transcription factor 6, an endoplasmic reticulum (ER) stress response transcription factor) mRNA expression and activation of Atf6 by MTA treatment. Forced expression of p50Atf6 (active form of Atf6) markedly enhanced Bglap mRNA expression. Chromatin immunoprecipitation assay was performed to investigate the increase in p50Atf6 binding to the Bglap promoter region by MTA treatment. Furthermore, knockdown of Atf6 gene expression by introduction of Tet-on Atf6 shRNA expression vector abrogated MTA-induced mineralization. These results suggest that MTA induces in vitro osteoblastogenesis through the Atf6–osteocalcin axis as ER stress signaling. Therefore, MTA in endodontic treatment may affect alveolar bone healing in the resorbed region caused by pulpal infection.
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Affiliation(s)
- Toyonobu Maeda
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Koriyama 963-8611, Japan
| | - Atsuko Suzuki
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Koriyama 963-8611, Japan
| | - Satoshi Yuzawa
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Koriyama 963-8611, Japan
| | - Yuh Baba
- Department of General Clinical Medicine, Ohu University School of Dentistry, Koriyama 963-8611, Japan
| | - Yuichi Kimura
- Division of Endodontics, Department of Conservative Dentistry, Ohu University School of Dentistry, Koriyama 963-8611, Japan
| | - Yasumasa Kato
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Koriyama 963-8611, Japan
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Buck TM, Jordan R, Lyons-Weiler J, Adelman JL, Needham PG, Kleyman TR, Brodsky JL. Expression of three topologically distinct membrane proteins elicits unique stress response pathways in the yeast Saccharomyces cerevisiae. Physiol Genomics 2015; 47:198-214. [PMID: 25759377 DOI: 10.1152/physiolgenomics.00101.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 03/04/2015] [Indexed: 01/11/2023] Open
Abstract
Misfolded membrane proteins are retained in the endoplasmic reticulum (ER) and are subject to ER-associated degradation, which clears the secretory pathway of potentially toxic species. While the transcriptional response to environmental stressors has been extensively studied, limited data exist describing the cellular response to misfolded membrane proteins. To this end, we expressed and then compared the transcriptional profiles elicited by the synthesis of three ER retained, misfolded ion channels: The α-subunit of the epithelial sodium channel, ENaC, the cystic fibrosis transmembrane conductance regulator, CFTR, and an inwardly rectifying potassium channel, Kir2.1, which vary in their mass, membrane topologies, and quaternary structures. To examine transcriptional profiles in a null background, the proteins were expressed in yeast, which was previously used to examine the degradation requirements for each substrate. Surprisingly, the proteins failed to induce a canonical unfolded protein response or heat shock response, although messages encoding several cytosolic and ER lumenal protein folding factors rose when αENaC or CFTR was expressed. In contrast, the levels of these genes were unaltered by Kir2.1 expression; instead, the yeast iron regulon was activated. Nevertheless, a significant number of genes that respond to various environmental stressors were upregulated by all three substrates, and compared with previous microarray data we deduced the existence of a group of genes that reflect a novel misfolded membrane protein response. These data indicate that aberrant proteins in the ER elicit profound yet unique cellular responses.
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Affiliation(s)
- Teresa M Buck
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rick Jordan
- GPCL Bioinformatics Analysis Core, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - James Lyons-Weiler
- GPCL Bioinformatics Analysis Core, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Joshua L Adelman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Patrick G Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Thomas R Kleyman
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania;
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Pagliarini V, Giglio P, Bernardoni P, De Zio D, Fimia GM, Piacentini M, Corazzari M. Downregulation of E2F1 during ER stress is required to induce apoptosis. J Cell Sci 2015; 128:1166-79. [PMID: 25616897 DOI: 10.1242/jcs.164103] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The endoplasmic reticulum (ER) has recently emerged as an alternative target to induce cell death in tumours, because prolonged ER stress results in the induction of apoptosis even in chemoresistant transformed cells. Here, we show that the DNA-damage-responsive pro-apoptotic factor E2F1 is unexpectedly downregulated during the ER stress-mediated apoptotic programme. E2F1 decline is a late event during the ER response and is mediated by the two unfolded protein response (UPR) sensors ATF6 and IRE1 (also known as ERN1). Whereas ATF6 directly interacts with the E2F1 promoter, IRE1 requires the involvement of the known E2F1 modulator E2F7, through the activation of its main target Xbp-1. Importantly, inhibition of the E2F1 decrease prevents ER-stress-induced apoptosis, whereas E2F1 knockdown efficiently sensitises cells to ER stress-dependent apoptosis, leading to the upregulation of two main factors in the UPR pro-apoptotic execution phase, Puma and Noxa (also known as BBC3 and PMAIP1, respectively). Our results point to a novel key role of E2F1 in the cell survival/death decision under ER stress, and unveil E2F1 inactivation as a valuable novel potential therapeutic strategy to increase the response of tumour cells to ER stress-based anticancer treatments.
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Affiliation(s)
- Vittoria Pagliarini
- National Institute for Infectious Disease 'L. Spallanzani' IRCCS, 00149 Rome, Italy
| | - Paola Giglio
- National Institute for Infectious Disease 'L. Spallanzani' IRCCS, 00149 Rome, Italy
| | - Paolo Bernardoni
- National Institute for Infectious Disease 'L. Spallanzani' IRCCS, 00149 Rome, Italy
| | - Daniela De Zio
- Department of Biology, Unit of the Dulbecco Telethon Institute, University of Rome 'Tor Vergata', 00133 Rome, Italy Cell Stress and Survival Unit, Danish Cancer Society Research Center, Strandboulevarden 49, Copenhagen DK-2100, Denmark
| | - Gian Maria Fimia
- National Institute for Infectious Disease 'L. Spallanzani' IRCCS, 00149 Rome, Italy Department of Biological and Environmental Science and Technology (Di.S.Te.B.A.), University of Salento, 73100 Lecce, Italy
| | - Mauro Piacentini
- National Institute for Infectious Disease 'L. Spallanzani' IRCCS, 00149 Rome, Italy Cellular and Developmental Lab, Department of Biology, University of Rome 'Tor Vergata', 00133 Rome, Italy
| | - Marco Corazzari
- National Institute for Infectious Disease 'L. Spallanzani' IRCCS, 00149 Rome, Italy Cellular and Developmental Lab, Department of Biology, University of Rome 'Tor Vergata', 00133 Rome, Italy
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Sozen E, Karademir B, Ozer NK. Basic mechanisms in endoplasmic reticulum stress and relation to cardiovascular diseases. Free Radic Biol Med 2015; 78:30-41. [PMID: 25452144 DOI: 10.1016/j.freeradbiomed.2014.09.031] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 09/03/2014] [Accepted: 09/26/2014] [Indexed: 01/30/2023]
Abstract
The folding process is an important step in protein synthesis for the functional shape or conformation of the protein. The endoplasmic reticulum (ER) is the main organelle for the correct folding procedure, which maintains the homeostasis of the organism. This process is normally well organized under unstressed conditions, whereas it may fail under oxidative and ER stress. The unfolded protein response (UPR) is a defense mechanism that removes the unfolded/misfolded proteins to prevent their accumulation, and two main degradation systems are involved in this defense, including the proteasome and autophagy. Cells decide which mechanism to use according to the type, severity, and duration of the stress. If the stress is too severe and in excess, the capacity of these degradation mechanisms, proteasomal degradation and autophagy, is not sufficient and the cell switches to apoptotic death. Because the accumulation of the improperly folded proteins leads to several diseases, it is important for the body to maintain this balance. Cardiovascular diseases are one of the important disorders related to failure of the UPR. Especially, protection mechanisms and the transition to apoptotic pathways have crucial roles in cardiac failure and should be highlighted in detailed studies to understand the mechanisms involved. This review is focused on the involvement of the proteasome, autophagy, and apoptosis in the UPR and the roles of these pathways in cardiovascular diseases.
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Affiliation(s)
- Erdi Sozen
- Department of Biochemistry, Faculty of Medicine, Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Betul Karademir
- Department of Biochemistry, Faculty of Medicine, Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Nesrin Kartal Ozer
- Department of Biochemistry, Faculty of Medicine, Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey.
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MORI K. The unfolded protein response: the dawn of a new field. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2015; 91:469-480. [PMID: 26560836 PMCID: PMC4754504 DOI: 10.2183/pjab.91.469] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/09/2015] [Indexed: 05/31/2023]
Abstract
Originating from cancer research in mammalian cultured cells, the entirely new field of the unfolded protein response (UPR) was born in 1988. The UPR is a transcriptional induction program coupled with intracellular signaling from the endoplasmic reticulum (ER) to the nucleus to maintain the homeostasis of the ER, an organelle which controls the quality of proteins destined for the secretory pathway. Extremely competitive analyses using the budding yeast Saccharomyces cerevisiae revealed that although signaling from both the ER and cell surface is initiated by activation of a transmembrane protein kinase, the mechanism downstream of ER-resident Ire1p, a sensor molecule of the UPR, is unique. Thus, unconventional spliceosome-independent mRNA splicing is utilized to produce the highly active transcription factor Hac1p. This is the autobiographical story of how a young and not yet independent scientist competed with a very famous full professor in the early days of UPR research, which ultimately lead to their sharing Lasker Basic Medical Research Award in 2014.
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Affiliation(s)
- Kazutoshi MORI
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
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45
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Fox RM, Andrew DJ. Transcriptional regulation of secretory capacity by bZip transcription factors. ACTA ACUST UNITED AC 2014; 10:28-51. [PMID: 25821458 PMCID: PMC4374484 DOI: 10.1007/s11515-014-1338-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cells of specialized secretory organs expand their secretory pathways to accommodate the increased protein load necessary for their function. The endoplasmic reticulum (ER), the Golgi apparatus and the secretory vesicles, expand not only the membrane components but also the protein machinery required for increased protein production and transport. Increased protein load causes an ER stress response akin to the Unfolded Protein Response (UPR). Recent work has implicated several bZip transcription factors in the regulation of protein components of the early secretory pathway necessary to alleviate this stress. Here, we highlight eight bZip transcription factors in regulating secretory pathway component genes. These include components of the three canonical branches of the UPR-ATF4, XBP1, and ATF6, as well as the five members of the Creb3 family of transcription factors.We review findings from both invertebrate and vertebrate model systems suggesting that all of these proteins increase secretory capacity in response to increased protein load. Finally, we propose that the Creb3 family of factors may have a dual role in secretory cell differentiation by also regulating the pathways necessary for cell cycle exit during terminal differentiation.
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Affiliation(s)
- Rebecca M Fox
- The Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Deborah J Andrew
- The Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Odisho T, Zhang L, Volchuk A. ATF6β regulates the Wfs1 gene and has a cell survival role in the ER stress response in pancreatic β-cells. Exp Cell Res 2014; 330:111-22. [PMID: 25447309 DOI: 10.1016/j.yexcr.2014.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/02/2014] [Accepted: 10/05/2014] [Indexed: 01/20/2023]
Abstract
Endoplasmic reticulum (ER) stress is implicated in pancreatic β-cell dysfunction and death resulting in type 2 diabetes. Activating transcription factor 6 (ATF6) is an essential component of the Unfolded Protein Response (UPR) and consists of two isoforms, ATF6α and ATF6β. Here we investigated the role of ATF6β. ATF6β mRNA was detected in pancreatic β-cell lines and rodent and human islets. We also detected ATF6β protein and production of the active form (ATF6βp60) in response to ER stress. Knock-down of ATF6β in INS-1 832/13 insulinoma cells did not affect mRNA induction of several major UPR genes in response to ER stress, suggesting ATF6β is not essential for the basic UPR. Expressing active ATF6βp60 or ATF6αp50 followed by microarray analysis showed that they regulate similar UPR genes, although some genes such as Wfs1 are ATF6β-specific. ATF6β, but not ATF6α, is able to bind the Wfs1 promoter and induce Wfs1 gene and protein expression. Knock-down of ATF6β increased the susceptibility of β-cells to ER stress-induced apoptosis, while overexpression of active ATF6βp60 reduced apoptosis. Thus, ATF6β is not essential for induction of most UPR genes, but is required to maintain cell survival in β-cells undergoing chronic ER stress, which in part relates to its ability to induce Wfs1, a pro-survival gene.
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Affiliation(s)
- Tanya Odisho
- Division of Advanced Diagnostics - Metabolism, Toronto General Research Institute, University Health Network, Canada; Department of Physiology, University of Toronto, Canada
| | - Liling Zhang
- Division of Advanced Diagnostics - Metabolism, Toronto General Research Institute, University Health Network, Canada
| | - Allen Volchuk
- Division of Advanced Diagnostics - Metabolism, Toronto General Research Institute, University Health Network, Canada; Department of Physiology, University of Toronto, Canada; Department of Biochemistry, University of Toronto, Canada.
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47
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Chen S, Zhao Y, Zhang Y, Zhang D. Fucoidan induces cancer cell apoptosis by modulating the endoplasmic reticulum stress cascades. PLoS One 2014; 9:e108157. [PMID: 25232957 PMCID: PMC4169461 DOI: 10.1371/journal.pone.0108157] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 08/17/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Cancer metastasis is the main cause leading to disease recurrence and high mortality in cancer patients. Therefore, inhibiting metastasis process or killing metastatic cancer cells by inducing apoptosis is of clinical importance in improving cancer patient survival. Previous studies revealed that fucoidan, a fucose-rich polysaccharide isolated from marine brown alga, is a promising natural product with significant anti-cancer activity. However, little is known about the role of endoplasmic reticulum (ER) stress in fucoidan-induced cell apoptosis. PRINCIPAL FINDINGS We reported that fucoidan treatment inhibits cell growth and induces apoptosis in cancer cells. Fucoidan treatments resulted in down-regulation of the glucose regulated protein 78 (GRP78) in the metastatic MDA-MB-231 breast cancer cells, and of the ER protein 29 (ERp29) in the metastatic HCT116 colon cancer cells. However, fucoidan treatment promoted ER Ca2+-dependent calmodulin-dependent kinase II (CaMKII) phosphorylation, Bcl-associated X protein (Bax) and caspase 12 expression in MDA-MB-231 cells, but not in HCT116 cells. In both types of cancer cells, fucoidan activated the phosphorylation of eukaryotic initiation factor 2 alpha (p-eIF2α)\CCAAT/enhancer binding protein homologous protein (CHOP) pro-apoptotic cascade and inhibited the phosphorylation of inositol-requiring kinase 1 (p-IRE-1)\X-box binding proteins 1 splicing (XBP-1s) pro-survival cascade. Furthermore, CHOP knockdown prevented DNA damage and cell death induced by fucoidan. CONCLUSION/SIGNIFICANCE Fucoidan exerts its anti-tumor function by modulating ER stress cascades. Contribution of ER stress to the fucoidan-induced cell apoptosis augments our understanding of the molecular mechanisms underlying its anti-tumour activity and provides evidence for the therapeutic application of fucoidan in cancer.
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Affiliation(s)
- Shaohua Chen
- Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University, Hangzhou, P. R. China
| | - Yang Zhao
- Centenary Institute of Cancer Medicine and Cell Biology, University of Sydney, Sydney, New South Wales, Australia
| | - Yu Zhang
- Department of Oncology, Zhejiang Hospital, Hangzhou, P. R. China
| | - Daohai Zhang
- Caner Research Group, The Canberra Hospital, ANU Medical School, The Australia National University, Canberra, Australia
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48
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Khodaee N, Ghasemi M, Saghiri R, Eliassi A. Endoplasmic reticulum membrane potassium channel dysfunction in high fat diet induced stress in rat hepatocytes. EXCLI JOURNAL 2014; 13:1075-87. [PMID: 26417322 PMCID: PMC4464507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 08/20/2014] [Indexed: 11/02/2022]
Abstract
In a previous study we reported the presence of a large conductance K(+) channel in the membrane of endoplasmic reticulum (ER) from rat hepatocytes. The channel open probability (Po) appeared voltage dependent and reached to a minimum 0.2 at +50 mV. Channel activity in this case was found to be totally inhibited at ATP concentration 2.5 mM, glibenclamide 100 µM and tolbutamide 400 µM. Existing evidence indicates an impairment of endoplasmic reticulum functions in ER stress condition. Because ER potassium channels have been involved in several ER functions including cytoprotection, apoptosis and calcium homeostasis, a study was carried out to consider whether the ER potassium channel function is altered in a high fat diet model of ER stress. Male Wistar rats were made ER stress for 2 weeks with a high fat diet. Ion channel incorporation of ER stress model into the bilayer lipid membrane allowed the characterization of K(+) channel. Our results indicate that the channel Po was significantly increased at voltages above +30 mV. Interestingly, addition of ATP 7.5 mM, glibenclamide 400 µM and tolbutamide 2400 µM totally inhibited the channel activities, 3-fold, 4-fold and 6-fold higher than that in the control groups, respectively. Our results thus demonstrate a modification in the ER K(+) channel gating properties and decreased sensitivity to drugs in membrane preparations coming from ER high fat model of ER stress, an effect potentially linked to a change in ER K(+) channel subunits in ER stress condition. Our results may provide new insights into the cellular mechanisms underlying ER dysfunctions in ER stress.
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Affiliation(s)
- Naser Khodaee
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran,Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran
| | - Maedeh Ghasemi
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran,Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran
| | - Reza Saghiri
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
| | - Afsaneh Eliassi
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran,Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran,*To whom correspondence should be addressed: Afsaneh Eliassi, Neurophysiology Research Center and Department of Physiology, Shahid Beheshti University of Medical Sciences, Evin, Tehran 19857, Iran. Tel-Fax: 9821-22439971, E-mail: ;
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49
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Sen D, Balakrishnan B, Jayandharan GR. Cellular unfolded protein response against viruses used in gene therapy. Front Microbiol 2014; 5:250. [PMID: 24904562 PMCID: PMC4033601 DOI: 10.3389/fmicb.2014.00250] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/07/2014] [Indexed: 01/21/2023] Open
Abstract
Viruses are excellent vehicles for gene therapy due to their natural ability to infect and deliver the cargo to specific tissues with high efficiency. Although such vectors are usually "gutted" and are replication defective, they are subjected to clearance by the host cells by immune recognition and destruction. Unfolded protein response (UPR) is a naturally evolved cyto-protective signaling pathway which is triggered due to endoplasmic reticulum (ER) stress caused by accumulation of unfolded/misfolded proteins in its lumen. The UPR signaling consists of three signaling pathways, namely PKR-like ER kinase, activating transcription factor 6, and inositol-requiring protein-1. Once activated, UPR triggers the production of ER molecular chaperones and stress response proteins to help reduce the protein load within the ER. This occurs by degradation of the misfolded proteins and ensues in the arrest of protein translation machinery. If the burden of protein load in ER is beyond its processing capacity, UPR can activate pro-apoptotic pathways or autophagy leading to cell death. Viruses are naturally evolved in hijacking the host cellular translation machinery to generate a large amount of proteins. This phenomenon disrupts ER homeostasis and leads to ER stress. Alternatively, in the case of gutted vectors used in gene therapy, the excess load of recombinant vectors administered and encountered by the cell can trigger UPR. Thus, in the context of gene therapy, UPR becomes a major roadblock that can potentially trigger inflammatory responses against the vectors and reduce the efficiency of gene transfer.
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Affiliation(s)
- Dwaipayan Sen
- Department of Hematology, Christian Medical College Vellore, India
| | | | - Giridhara R Jayandharan
- Department of Hematology, Christian Medical College Vellore, India ; Centre for Stem Cell Research, Christian Medical College Vellore, India
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50
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Zhang SX, Sanders E, Fliesler SJ, Wang JJ. Endoplasmic reticulum stress and the unfolded protein responses in retinal degeneration. Exp Eye Res 2014; 125:30-40. [PMID: 24792589 DOI: 10.1016/j.exer.2014.04.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/02/2014] [Accepted: 04/18/2014] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is the primary intracellular organelle responsible for protein and lipid biosynthesis, protein folding and trafficking, calcium homeostasis, and several other vital processes in cell physiology. Disturbance in ER function results in ER stress and subsequent activation of the unfolded protein response (UPR). The UPR up-regulates ER chaperones, reduces protein translation, and promotes clearance of cytotoxic misfolded proteins to restore ER homeostasis. If this vital process fails, the cell will be signaled to enter apoptosis, resulting in cell death. Sustained ER stress also can trigger an inflammatory response and exacerbate oxidative stress, both of which contribute synergistically to tissue damage. Studies performed over the past decade have implicated ER stress in a broad range of human diseases, including neurodegenerative diseases, cancer, diabetes, and vascular disorders. Several of these diseases also entail retinal dysfunction and degeneration caused by injury to retinal neurons and/or to the blood vessels that supply retinal cells with nutrients, trophic and homeostatic factors, oxygen, and other essential molecules, as well as serving as a conduit for removal of waste products and potentially toxic substances from the retina. Collectively, such injuries represent the leading cause of blindness world-wide in all age groups. Herein, we summarize recent progress on the study of ER stress and UPR signaling in retinal biology and discuss the molecular mechanisms and the potential clinical applications of targeting ER stress as a new therapeutic approach to prevent and treat neuronal degeneration in the retina.
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Affiliation(s)
- Sarah X Zhang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA.
| | - Emily Sanders
- Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA; Research Service, Veterans Administration Western New York Healthcare System, Buffalo, NY, USA
| | - Joshua J Wang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA
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