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Tian S, Liu W, Liu B, Ye F, Xu Z, Wan Q, Li Y, Zhang X. Mechanistic study of C 5F 10O-induced lung toxicity in rats: An eco-friendly insulating gas alternative to SF 6. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170271. [PMID: 38262248 DOI: 10.1016/j.scitotenv.2024.170271] [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: 11/22/2023] [Revised: 12/23/2023] [Accepted: 01/17/2024] [Indexed: 01/25/2024]
Abstract
The global warming and other environmental problems caused by SF6 emissions can be reduced due to the widespread use of eco-friendly insulating gas, perfluoropentanone (C5F10O). However, there is an exposure risk to populations in areas near C5F10O equipment, so it is important to clarify its biosafety and pathogenesis before large-scale application. In this paper, histopathology, transcriptomics, 4D-DIA proteomics, and LC-MS metabolomics of rats exposed to 2000 ppm and 6000 ppm C5F10O are analyzed to reveal the mechanisms of toxicity and health risks. Histopathological shows that inflammatory cell infiltration, epithelial cell hyperplasia, and alveolar atrophy accompanied by alveolar wall thickening are present in both low-dose and high-dose groups. Analysis of transcriptomic and 4D-DIA proteomic show that Cell cycle and DNA replication can be activated by both 2000 ppm and 6000 ppm C5F10O to induce cell proliferation. In addition, it also leads to the activation of pathways such as Antigen processing and presentation, Cell adhesion molecules and Complement and coagulation cascades, T cell receptor signal path, Th1 and T cell receptor signal path, Th1 and Th2 cell differentiation, complement and coagulation cascades. Finally, LC-MS metabolomics analysis confirms that the metabolic pathways associated with glycerophospholipids, arachidonic acid, and linoleic acid are disrupted and become more severe with increasing doses. The mechanism of lung toxicity caused by C5F10O is systematically expounded based on the multi-omics analysis and provided biosafety references for further promotion and application of C5F10O.
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Affiliation(s)
- Shuangshuang Tian
- Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment, Hubei University of Technology, Wuhan 430068, China
| | - Weihao Liu
- Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment, Hubei University of Technology, Wuhan 430068, China
| | - Benli Liu
- Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment, Hubei University of Technology, Wuhan 430068, China
| | - Fanchao Ye
- Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment, Hubei University of Technology, Wuhan 430068, China
| | - Zhenjie Xu
- School of Life Sciences, Westlake University, Hangzhou, China
| | - Qianqian Wan
- Zhongnan Hospital, Wuhan University, Wuhan, China.
| | - Yi Li
- School of Electrical Engineering and Automation, Wuhan University, Wuhan, China
| | - Xiaoxing Zhang
- Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment, Hubei University of Technology, Wuhan 430068, China; School of Electrical Engineering and Automation, Wuhan University, Wuhan, China.
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He H, Qi R, Cui J, Liu M, Guan B, Zhou Y, Zhang Y, Hao X, Wang H, Liu H. Lipid characteristics of lung tissue in silicosis rat model were studied based on lipid metabolomics. Toxicol Lett 2024; 391:111-119. [PMID: 38061438 DOI: 10.1016/j.toxlet.2023.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/08/2023] [Accepted: 12/04/2023] [Indexed: 12/22/2023]
Abstract
Silicosis is a common occupational disease caused by the long-term inhalation of large amounts of silica dust. Lipid metabolism plays an important role in the progression of silicosis, but its contributing mechanism remains unclear. The aim of this study was to investigate the differential lipid metabolites and active metabolic pathways in silicosis rat lung tissue. We first constructed a silicosis rat model, and randomly divided 24 male SD rats into control group (C), silicosis group for 1 week (S1W), silicosis group for 2 weeks (S2W) and silicosis group for 4 weeks (S4W) with 6 rats in each group. 1 mL SiO2 suspension (50 mg/mL) or normal saline were injected into the trachea, and the rats were killed at 1 week, 2 weeks and 4 weeks, respectively. The lung tissue pathology of the rats was observed by HE staining and VG staining, and the plasma TC and FC levels were detected by the kit. Western blot was used to detect the expression of lipid-related factors CD36, PGC1α and LXR. In addition, lipidomics analysis of lung tissue samples was performed using UPLC-IMS-QTOF mass spectrometer to screen out potential differential metabolites in silicosis models and analyze lipid enrichment, and verified the expression of differential gene CHPT1 in the metabolic pathway. HE and VG staining showed that the number of nodules and fibrosis increased in a time-dependent manner in the silicosis model group, and the levels of TC, FC and CE in silicosis plasma increased. Western blot results showed that PGC1α and LXR decreased in the silicosis model group, while CD36 expression increased. In addition, metabolomics screened out 28 differential metabolites in the S1W group, 32 in the S2W group, and 22 in the S4W group, and found that the differential metabolites were mainly enriched in metabolic pathways such as glycerophospholipid metabolism and ether lipid metabolism, and the expression of differential gene CHPT1 in the metabolic pathway was decreased in the silicosis model group. These results suggest that there are significant changes in lipid metabolites in lung tissue in silicosis rat models, and glycerophospholipid metabolism was significantly enriched, suggesting that glycerophospholipids play an important role in the progression of silicosis. The differential metabolites and pathways reported in this study may provide new ideas for the pathogenesis of silicosis.
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Affiliation(s)
- Hailan He
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Rong Qi
- School of Clinical Medicine, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Jie Cui
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Mingming Liu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Bo Guan
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Yufan Zhou
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Yingshu Zhang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Xiaohui Hao
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Hongli Wang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China.
| | - Heliang Liu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China.
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Hrach VL, King WR, Nelson LD, Conklin S, Pollock JA, Patton-Vogt J. The acyltransferase Gpc1 is both a target and an effector of the unfolded protein response in Saccharomyces cerevisiae. J Biol Chem 2023; 299:104884. [PMID: 37269946 PMCID: PMC10331479 DOI: 10.1016/j.jbc.2023.104884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 05/25/2023] [Accepted: 05/27/2023] [Indexed: 06/05/2023] Open
Abstract
The unfolded protein response (UPR) is sensitive to proteotoxic and membrane bilayer stress, both of which are sensed by the ER protein Ire1. When activated, Ire1 splices HAC1 mRNA, producing a transcription factor that targets genes involved in proteostasis and lipid metabolism, among others. The major membrane lipid phosphatidylcholine (PC) is subject to phospholipase-mediated deacylation, producing glycerophosphocholine (GPC), followed by reacylation of GPC through the PC deacylation/reacylation pathway (PC-DRP). The reacylation events occur via a two-step process catalyzed first by the GPC acyltransferase Gpc1, followed by acylation of the lyso-PC molecule by Ale1. However, whether Gpc1 is critical for ER bilayer homeostasis is unclear. Using an improved method for C14-choline-GPC radiolabeling, we first show that loss of Gpc1 results in abrogation of PC synthesis through PC-DRP and that Gpc1 colocalizes with the ER. We then probe the role of Gpc1 as both a target and an effector of the UPR. Exposure to the UPR-inducing compounds tunicamycin, DTT, and canavanine results in a Hac1-dependent increase in GPC1 message. Further, cells lacking Gpc1 exhibit increased sensitivity to those proteotoxic stressors. Inositol limitation, known to induce the UPR via bilayer stress, also induces GPC1 expression. Finally, we show that loss of GPC1 induces the UPR. A gpc1Δ mutant displays upregulation of the UPR in strains expressing a mutant form of Ire1 that is unresponsive to unfolded proteins, indicating that bilayer stress is responsible for the observed upregulation. Collectively, our data indicate an important role for Gpc1 in yeast ER bilayer homeostasis.
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Affiliation(s)
- Victoria Lee Hrach
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - William R King
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Laura D Nelson
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Shane Conklin
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - John A Pollock
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Jana Patton-Vogt
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA.
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Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the coronavirus disease 2019 (COVID-19) pandemic. Of particular interest for this topic are the signaling cascades that regulate cell survival and death, two opposite cell programs whose control is hijacked by viral infections. The AKT and the Unfolded Protein Response (UPR) pathways, which maintain cell homeostasis by regulating these two programs, have been shown to be deregulated during SARS-CoVs infection as well as in the development of cancer, one of the most important comorbidities in relation to COVID-19. Recent evidence revealed two way crosstalk mechanisms between the AKT and the UPR pathways, suggesting that they might constitute a unified homeostatic control system. Here, we review the role of the AKT and UPR pathways and their interaction in relation to SARS-CoV-2 infection as well as in tumor onset and progression. Feedback regulation between AKT and UPR pathways emerges as a master control mechanism of cell decision making in terms of survival or death and therefore represents a key potential target for developing treatments for both viral infection and cancer. In particular, drug repositioning, the investigation of existing drugs for new therapeutic purposes, could significantly reduce time and costs compared to de novo drug discovery.
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Seo B, Coates D, Lewis J, Seymour G, Rich A. Unfolded protein response is involved in the metabolic and apoptotic regulation of oral squamous cell carcinoma. Pathology 2022; 54:874-881. [DOI: 10.1016/j.pathol.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/21/2022] [Accepted: 04/07/2022] [Indexed: 11/17/2022]
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Saito RDF, Andrade LNDS, Bustos SO, Chammas R. Phosphatidylcholine-Derived Lipid Mediators: The Crosstalk Between Cancer Cells and Immune Cells. Front Immunol 2022; 13:768606. [PMID: 35250970 PMCID: PMC8889569 DOI: 10.3389/fimmu.2022.768606] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/13/2022] [Indexed: 01/16/2023] Open
Abstract
To become resistant, cancer cells need to activate and maintain molecular defense mechanisms that depend on an energy trade-off between resistance and essential functions. Metabolic reprogramming has been shown to fuel cell growth and contribute to cancer drug resistance. Recently, changes in lipid metabolism have emerged as an important driver of resistance to anticancer agents. In this review, we highlight the role of choline metabolism with a focus on the phosphatidylcholine cycle in the regulation of resistance to therapy. We analyze the contribution of phosphatidylcholine and its metabolites to intracellular processes of cancer cells, both as the major cell membrane constituents and source of energy. We further extended our discussion about the role of phosphatidylcholine-derived lipid mediators in cellular communication between cancer and immune cells within the tumor microenvironment, as well as their pivotal role in the immune regulation of therapeutic failure. Changes in phosphatidylcholine metabolism are part of an adaptive program activated in response to stress conditions that contribute to cancer therapy resistance and open therapeutic opportunities for treating drug-resistant cancers.
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Affiliation(s)
- Renata de Freitas Saito
- Centro de Investigação Translacional em Oncologia (LIM24), Departamento de Radiologia e Oncologia, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, São Paulo, Brazil
| | - Luciana Nogueira de Sousa Andrade
- Centro de Investigação Translacional em Oncologia (LIM24), Departamento de Radiologia e Oncologia, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, São Paulo, Brazil
| | - Silvina Odete Bustos
- Centro de Investigação Translacional em Oncologia (LIM24), Departamento de Radiologia e Oncologia, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, São Paulo, Brazil
| | - Roger Chammas
- Centro de Investigação Translacional em Oncologia (LIM24), Departamento de Radiologia e Oncologia, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, São Paulo, Brazil
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Li F, Lin Q, Shen L, Zhang Z, Wang P, Zhang S, Xing Q, Xia Z, Zhao Z, Zhang Y, Zhu B. The diagnostic value of endoplasmic reticulum stress-related specific proteins GRP78 and CHOP in patients with sepsis: a diagnostic cohort study. ANNALS OF TRANSLATIONAL MEDICINE 2022; 10:470. [PMID: 35571390 PMCID: PMC9096362 DOI: 10.21037/atm-22-1445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/20/2022] [Indexed: 11/17/2022]
Abstract
Background Sepsis is a life-threatening disease with high mortality. Early diagnosis is critical as early treatment improves outcomes. The protein levels of glucose regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP), markers of endoplasmic reticulum stress (ERS) activation, were reported increasing rapidly and continuously in the serum of patients with sepsis. Therefore, they might serve as a potential biomarker for sepsis diagnosis. This study aimed to analyze the role of GRP78 and CHOP in the diagnosis of patients with sepsis. Methods This study enrolled a total of 92 infected patients with or without sepsis who were admitted to the intensive care unit (ICU) from February 1, 2018 to September 30, 2018. According to 2016 SCCM/ESICM Sepsis 3.0 diagnostic criteria, patients with sepsis were allocated into group I (sepsis infected group) and patients without sepsis were allocated into group II (non-sepsis infected group). Serum samples were collected on days 1, 2, 3, and 7 after admission to ICU, and the concentrations of GRP78 and CHOP in the serum were analyzed by enzyme-linked immunosorbent assay (ELISA). The diagnostic ability of GRP78, CHOP, and other traditional inflammatory markers was assessed with receiver operating characteristic (ROC)/area under the ROC curves (AUC) analysis. Patients were shortly follow-up for the 28-day mortality. Results Serum GRP78 and CHOP levels in group I patients were higher than that in group II patients (P=0.021, P=0.00, respectively). When GRP78 was used to diagnose sepsis, the maximum area under the ROC curve (AUC) was 0.771 (95% CI: 0.662-0.880) and the optimal threshold was 157.29 ng/L (sensitivity, 75.0%; specificity, 73.1%) on day 2. When CHOP was used for the diagnosis of sepsis, the maximum AUC was 0.813(95% CI: 0.721-0.906) and the optimal threshold was 4.915 ng/L (sensitivity, 57.7%; specificity, 96.2%) on day 2. Conclusions Compared with traditional inflammatory markers, ERS-related specific proteins GRP78 and CHOP have better sensitivity and specificity in the diagnosis of sepsis, which is helpful for clinicians in the diagnosis of sepsis.
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Affiliation(s)
- Fangfang Li
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Qionghua Lin
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Lihua Shen
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Zhongwei Zhang
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Pengmei Wang
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Shan Zhang
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Qian Xing
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Zhili Xia
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Zhiyong Zhao
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Yunhe Zhang
- Department of Intensive Care Unit, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Biao Zhu
- Department of Anaesthesia, Critical Care and Pain Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
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Ishiwata-Kimata Y, Le QG, Kimata Y. Induction and Aggravation of the Endoplasmic-Reticulum Stress by Membrane-Lipid Metabolic Intermediate Phosphatidyl- N-Monomethylethanolamine. Front Cell Dev Biol 2022; 9:743018. [PMID: 35071223 PMCID: PMC8770322 DOI: 10.3389/fcell.2021.743018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 12/14/2021] [Indexed: 11/13/2022] Open
Abstract
Phosphatidylcholine (PC) is produced via two distinct pathways in both hepatocytes and yeast, Saccharomyces cerevisiae. One of these pathways involves the sequential methylation of phosphatidylethanolamine (PE). In yeast cells, the methyltransferase, Cho2, converts PE to phosphatidylmonomethylethanolamine (PMME), which is further modified to PC by another methyltransferase, Opi3. On the other hand, free choline is utilized for PC production via the Kennedy pathway. The blockage of PC production is well known to cause endoplasmic reticulum (ER) stress and activate the ER-stress sensor, Ire1, to induce unfolded protein response (UPR). Here, we demonstrate that even when free choline is sufficiently supplied, the opi3Δ mutation, but not the cho2 Δ mutation, induces the UPR. The UPR was also found to be induced by CHO2 overexpression. Further, monomethylethanolamine, which is converted to PMME probably through the Kennedy pathway, caused or potentiated ER stress in both mammalian and yeast cells. We thus deduce that PMME per se is an ER-stressing molecule. Interestingly, spontaneously accumulated PMME seemed to aggravate ER stress in yeast cells. Collectively, our findings demonstrate the multiple detrimental effects of the low-abundance phospholipid species, PMME.
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Affiliation(s)
- Yuki Ishiwata-Kimata
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Quynh Giang Le
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Yukio Kimata
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
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Lee H, Kwon Y, Jin H, Liu H, Kang W, Chun Y, Bae J, Choi H. Anticancer activity and metabolic profile alterations by ortho‐topolin riboside in in vitro and in vivo models of non‐small cell lung cancer. FASEB J 2022; 36:e22127. [DOI: 10.1096/fj.202101333r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/09/2021] [Accepted: 12/16/2021] [Indexed: 12/24/2022]
Affiliation(s)
- Hwanhui Lee
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Yeo‐Jung Kwon
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Hanyong Jin
- Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of Education College of Pharmacy Yanbian University Yanji China
| | - Heifeng Liu
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Wonku Kang
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Young‐Jin Chun
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Jeehyeon Bae
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Hyung‐Kyoon Choi
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
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Ma P, Wang Z, Wang Y, Hou B, Sun J, Tian H, Li B, Shui G, Yang X, Yang X, Qiang G, Liew CW, Du G. Integration of Metabolomics and Transcriptomics Reveals Ketone Body and Lipid Metabolism Disturbance Related to ER Stress in the Liver. J Proteome Res 2021; 20:3875-3888. [PMID: 34270263 DOI: 10.1021/acs.jproteome.1c00167] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Once protein synthesis is excessive or misfolded protein becomes aggregated, which eventually overwhelms the capacity of the endoplasmic reticulum (ER), a state named ER stress would be reached. ER stress could affect many tissues, especially the liver, in which nonalcoholic fatty liver disease, liver steatosis, etc. have been reported relative. However, there is still a lack of systematic insight into ER stress in the liver, which can be obtained by integrating metabolomics and transcriptomics of the tissue. Here, tunicamycin was utilized to induce ER stress in C57BL/6N mice. Microarray and untargeted metabolomics were performed to identify the genes and metabolites significantly altered in liver tissues. Surprisingly, apart from the predictable unfolded protein response, liver lipid, arginine, and proline metabolisms were affirmed to be related to ER stress. Also, the ketone body metabolism changed most prominently in response to ER stress, with few studies backing. What is more, succinate receptor 1 (Sucnr1) may be a novel marker and therapeutical target of liver ER stress. In this study, the combination of the metabolome and transcriptome provided reliable information about liver pathological processes, including key relative pathways, potential markers, and targets involved in ER stress of the liver.
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Affiliation(s)
- Peng Ma
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Zijing Wang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Yisa Wang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China.,College of Pharmacy, Harbin University of Commerce, Harbin 510006, China
| | - Biyu Hou
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Jialin Sun
- Department of Pharmacy, The Affiliated Hospital of Qingdao University, Qindao 266000, China
| | - He Tian
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bowen Li
- LipidALL Technologies Ltd., Changzhou 213125, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiuying Yang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Xinyu Yang
- Department of Pharmaceutical Analysis, College of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast BT7 1NN, U.K
| | - Guifen Qiang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Chong Wee Liew
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, 60612 Illinois, United States
| | - Guanhua Du
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
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11
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Carry PM, Vanderlinden LA, Johnson RK, Buckner T, Fiehn O, Steck AK, Kechris K, Yang I, Fingerlin TE, Rewers M, Norris JM. Phospholipid Levels at Seroconversion Are Associated With Resolution of Persistent Islet Autoimmunity: The Diabetes Autoimmunity Study in the Young. Diabetes 2021; 70:1592-1601. [PMID: 33863802 PMCID: PMC8336007 DOI: 10.2337/db20-1251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/11/2021] [Indexed: 12/14/2022]
Abstract
Reversion of islet autoimmunity (IA) may point to mechanisms that prevent IA progression. We followed 199 individuals who developed IA during the Diabetes Autoimmunity Study in the Young. Untargeted metabolomics was performed in serum samples following IA. Cox proportional hazards models were used to test whether the metabolites (2,487) predicted IA reversion: two or more consecutive visits negative for all autoantibodies. We conducted a principal components analysis (PCA) of the top metabolites; |hazard ratio (HR) >1.25| and nominal P < 0.01. Phosphatidylcholine (16:0_18:1(9Z)) was the strongest individual metabolite (HR per 1 SD 2.16, false discovery rate (FDR)-adjusted P = 0.0037). Enrichment analysis identified four clusters (FDR P < 0.10) characterized by an overabundance of sphingomyelin (d40:0), phosphatidylcholine (16:0_18:1(9Z)), phosphatidylcholine (30:0), and l-decanoylcarnitine. Overall, 63 metabolites met the criteria for inclusion in the PCA. PC1 (HR 1.4, P < 0.0001), PC2 (HR 0.85, P = 0.0185), and PC4 (HR 1.28, P = 0.0103) were associated with IA reversion. Given the potential influence of diet on the metabolome, we investigated whether nutrients were correlated with PCs. We identified 20 nutrients that were correlated with the PCs (P < 0.05). Total sugar intake was the top nutrient. Overall, we identified an association between phosphatidylcholine, sphingomyelin, and carnitine levels and reversion of IA.
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Affiliation(s)
- Patrick M Carry
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO
| | | | - Randi K Johnson
- Colorado Center for Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Teresa Buckner
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO
| | | | - Andrea K Steck
- Barbara Davis Center for Diabetes, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Katerina Kechris
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO
| | - Ivana Yang
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Tasha E Fingerlin
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO
- Department of Immunology and Genomic Medicine, National Jewish Health, Denver, CO
| | - Marian Rewers
- Barbara Davis Center for Diabetes, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Jill M Norris
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO
- Barbara Davis Center for Diabetes, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO
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12
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Gilardini Montani MS, Benedetti R, Piconese S, Pulcinelli FM, Timperio AM, Romeo MA, Masuelli L, Mattei M, Bei R, D'Orazi G, Cirone M. PGE2 Released by Pancreatic Cancer Cells Undergoing ER Stress Transfers the Stress to DCs Impairing Their Immune Function. Mol Cancer Ther 2021; 20:934-945. [PMID: 33632872 DOI: 10.1158/1535-7163.mct-20-0699] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/24/2020] [Accepted: 02/09/2021] [Indexed: 11/16/2022]
Abstract
This study shows that pancreatic cancer cells undergoing cell death by valproic acid (VPA) treatment activated dendritic cells (DCs) more efficiently than those treated with trichostatin A (TSA), as demonstrated by CD86 and CD80 surface expression. Surprisingly though, DCs cultured in the presence of supernatant derived from VPA-treated cancer cells showed a reduced allostimulatory capacity and an increased release of IL10 and IL8 cytokines in comparison with those exposed to TSA-treated cell culture supernatant. Searching for molecular mechanisms leading to such differences, we found that VPA treatment dysregulated choline metabolism and triggered a stronger endoplasmic reticulum (ER) stress in pancreatic cancer cells than TSA, upregulating CCAAT/enhancer-binding protein homologous protein, and activated cyclooxygenase-2, thus promoting the release of prostaglandin (PG) E2. Interestingly, dysfunctional DCs cultured in the presence of VPA-treated cells culture supernatant showed a higher level of intracellular reactive oxygen species, 4-hydroxy-trans-2-nonenal protein adducts, and ER stress, as evidenced by the upregulation of spliced X-box binding protein 1 (XBP1s), effects that were reduced when DCs were exposed to supernatant of cancer cells treated with Celecoxib before VPA. Celecoxib prevented PGE2 release, restoring the function of DCs exposed to VPA-treated cells culture supernatant, and a similar effect was obtained by silencing XBP1s in DCs treated with VPA-treated cells culture supernatant. These results suggest that PGE2 could be one of the yet unidentified factors able to transfer the stress from cancer cells to DCs, resulting in an impairment of their function.
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Affiliation(s)
- Maria Saveria Gilardini Montani
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy
| | - Rossella Benedetti
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy
| | - Silvia Piconese
- Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy.,Department of Internal Clinical, Anaesthesiologic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy
| | | | - Anna Maria Timperio
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Maria Anele Romeo
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy
| | - Laura Masuelli
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Maurizio Mattei
- Centro di Servizi Interdipartimentale-Stazione per la Tecnologia Animale, University of Rome "Tor Vergata," Rome, Italy; Department of Biology, University of Rome "Tor Vergata," Rome, Italy
| | - Roberto Bei
- Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata,' Rome, Italy
| | - Gabriella D'Orazi
- Department of Research, IRCCS Regina Elena National Cancer Institute, Rome, Italy.,Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio," Chieti, Italy
| | - Mara Cirone
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy. .,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy
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13
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Sur S, Nakanishi H, Flaveny C, Ippolito JE, McHowat J, Ford DA, Ray RB. Inhibition of the key metabolic pathways, glycolysis and lipogenesis, of oral cancer by bitter melon extract. Cell Commun Signal 2019; 17:131. [PMID: 31638999 PMCID: PMC6802351 DOI: 10.1186/s12964-019-0447-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/27/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Metabolic reprogramming is one of the hallmarks of cancer which favours rapid energy production, biosynthetic capabilities and therapy resistance. In our previous study, we showed bitter melon extract (BME) prevents carcinogen induced mouse oral cancer. RNA sequence analysis from mouse tongue revealed a significant modulation in "Metabolic Process" by altering glycolysis and lipid metabolic pathways in BME fed group as compared to cancer group. In present study, we evaluated the effect of BME on glycolysis and lipid metabolism pathways in human oral cancer cells. METHODS Cal27 and JHU022 cells were treated with BME. RNA and protein expression were analysed for modulation of glycolytic and lipogenesis genes by quantitative real-time PCR, western blot analyses and immunofluorescence. Lactate and pyruvate level was determined by GC/MS. Extracellular acidification and glycolytic rate were measured using the Seahorse XF analyser. Shotgun lipidomics in Cal27 and JHU022 cell lines following BME treatment was performed by ESI/ MS. ROS was measured by FACS. RESULTS Treatment with BME on oral cancer cell lines significantly reduced mRNA and protein expression levels of key glycolytic genes SLC2A1 (GLUT-1), PFKP, LDHA, PKM and PDK3. Pyruvate and lactate levels and glycolysis rate were reduced in oral cancer cells following BME treatment. In lipogenesis pathway, we observed a significant reduction of genes involves in fatty acid biogenesis, ACLY, ACC1 and FASN, at the mRNA and protein levels following BME treatment. Further, BME treatment significantly reduced phosphatidylcholine, phosphatidylethanolamine, and plasmenylethanolamine, and reduced iPLA2 activity. Additionally, BME treatment inhibited lipid raft marker flotillin expression and altered its subcellular localization. ER-stress associated CHOP expression and generation of mitochondrial reactive oxygen species were induced by BME, which facilitated apoptosis. CONCLUSION Our study revealed that bitter melon extract inhibits glycolysis and lipid metabolism and induces ER and oxidative stress-mediated cell death in oral cancer. Thus, BME-mediated metabolic reprogramming of oral cancer cells will have important preventive and therapeutic implications along with conventional therapies.
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Affiliation(s)
- Subhayan Sur
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
| | - Hiroshi Nakanishi
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
| | - Colin Flaveny
- 0000 0004 1936 9342grid.262962.bDepartment of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO USA
| | - Joseph E. Ippolito
- 0000 0001 2355 7002grid.4367.6Mallinckrodt Institute of Radiology, Washington University in Saint Louis School of Medicine, Saint Louis, MO USA
| | - Jane McHowat
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
| | - David A. Ford
- 0000 0004 1936 9342grid.262962.bBiochemistry and Molecular Biology, Saint Louis University, Saint Louis, MO USA
| | - Ratna B. Ray
- 0000 0004 1936 9342grid.262962.bDepartment of Pathology, Saint Louis University, 1100 South Grand Boulevard, St. Louis, MO 63104 USA
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14
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Lin YC, Kanehara K, Nakamura Y. Arabidopsis CHOLINE/ETHANOLAMINE KINASE 1 (CEK1) is a primary choline kinase localized at the endoplasmic reticulum (ER) and involved in ER stress tolerance. THE NEW PHYTOLOGIST 2019; 223:1904-1917. [PMID: 31087404 DOI: 10.1111/nph.15915] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/05/2019] [Indexed: 05/25/2023]
Abstract
Choline kinase catalyzes the initial reaction step of choline metabolism that produces phosphocholine, a prerequisite for the biosynthesis of a primary phospholipid phosphatidylcholine. However, the primary choline kinase and its role in plant growth remained elusive in seed plants. Here, we showed that Arabidopsis CHOLINE/ETHANOLAMINE KINASE 1 (CEK1) encodes functional CEK that prefers choline than ethanolamine as a substrate in vitro and affects contents of choline and phosphocholine but not phosphatidylcholine in vivo. CEK1 is localized at endoplasmic reticulum (ER); upon tunicamycin-induced ER stress, a null mutant of CEK1 showed hypersensitive phenotype in seedlings, albeit with no enhanced choline kinase activity. Our results demonstrate that CEK1 is a primary ER-localized choline kinase in vivo that is required for ER stress tolerance possibly through the modulation of choline metabolites.
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Affiliation(s)
- Ying-Chen Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Kazue Kanehara
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Yuki Nakamura
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
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15
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Lee YK, Park JE, Lee M, Hardwick JP. Hepatic lipid homeostasis by peroxisome proliferator-activated receptor gamma 2. LIVER RESEARCH 2018; 2:209-215. [PMID: 31245168 PMCID: PMC6594548 DOI: 10.1016/j.livres.2018.12.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ or PPARG) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. It plays a master role in the differentiation and proliferation of adipose tissues. It has two major isoforms, PPARγ1 and PPARγ2, encoded from a single gene using two separate promoters and alternative splicing. Among them, PPARγ2 is most abundantly expressed in adipocytes and plays major adipogenic and lipogenic roles in the tissue. Furthermore, it has been shown that PPARγ2 is also expressed in the liver, specifically in hepatocytes, and its expression level positively correlates with fat accumulation induced by pathological conditions such as obesity and diabetes. Knockout of the hepatic Pparg gene ameliorates hepatic steatosis induced by diet or genetic manipulations. Transcriptional activation of Pparg in the liver induces the adipogenic program to store fatty acids in lipid droplets as observed in adipocytes. Understanding how the hepatic Pparg gene expression is regulated will help develop preventative and therapeutic treatments for non-alcoholic fatty liver disease (NAFLD). Due to the potential adverse effect of hepatic Pparg gene deletion on peripheral tissue functions, therapeutic interventions that target PPARγ for fatty liver diseases require fine-tuning of this gene's expression and transcriptional activity.
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Affiliation(s)
- Yoon Kwang Lee
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA,Corresponding author. Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA., (Y.K. Lee)
| | - Jung Eun Park
- Department of Food Science and Human Nutrition, Chonbuk National University, Deokjin-gu, Jeonju, Republic of Korea
| | - Mikang Lee
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA
| | - James P. Hardwick
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA
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16
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Şengelen A, Önay-Uçar E. Rosmarinic acid and siRNA combined therapy represses Hsp27 (HSPB1) expression and induces apoptosis in human glioma cells. Cell Stress Chaperones 2018; 23:885-896. [PMID: 29627902 PMCID: PMC6111096 DOI: 10.1007/s12192-018-0896-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 02/10/2018] [Accepted: 03/24/2018] [Indexed: 12/11/2022] Open
Abstract
High expression of Hsp27 in glioma cells has been closely associated with tumor cell proliferation and apoptosis inhibition. The aim of the present study was to asses the effects of rosmarinic acid (RA) on Hsp27 expression and apoptosis in non-transfected and transfected human U-87 MG cells. The effect of rosmarinic acid was compared to quercetin, which is known to be a good Hsp27 inhibitor. In order to block the expression of Hsp27 gene (HSPB1), transfection with specific siRNAs was performed. Western blotting technique was used to assess the Hsp27 expression, and caspase-3 colorimetric activity assay was performed to determine apoptosis induction. According to the results, it was found that RA and quercetin effectively silenced Hsp27 and both agents induced apoptosis by activating the caspase-3 pathway. Eighty and 215 μM RA decreased the level of Hsp27 by 28.8 and 46.7% and induced apoptosis by 30 and 54%, respectively. For the first time, we reported that rosmarinic acid has the ability to trigger caspase-3 induced apoptosis in human glioma cells. As a result of siRNA transfection, the Hsp27 gene was silenced by ~ 50% but did not cause a statistically significant change in caspase-3 activation. It was also observed that apoptosis was induced at a higher level as a result of Hsp27 siRNA and subsequent quercetin or RA treatment. siRNA transfection and 215 μM RA treatment suppressed Hsp27 expression level by 90.5% and increased caspase-3 activity by 58%. Herein, we demonstrated that RA administered with siRNA seems to be a potent combination for glioblastoma therapy.
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Affiliation(s)
- Aslıhan Şengelen
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Vezneciler, 34134, Istanbul, Turkey.
| | - Evren Önay-Uçar
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Vezneciler, 34134, Istanbul, Turkey
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17
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Wu K, Luo Z, Hogstrand C, Chen GH, Wei CC, Li DD. Zn Stimulates the Phospholipids Biosynthesis via the Pathways of Oxidative and Endoplasmic Reticulum Stress in the Intestine of Freshwater Teleost Yellow Catfish. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9206-9214. [PMID: 30052432 DOI: 10.1021/acs.est.8b02967] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The hypothesis of our study was that waterborne Zn exposure evoked phospholipids (PL) biosynthesis to compensate for the loss of membrane integrity, and the pathways of oxidative stress and endoplasmic reticulum (ER) stress mediated the Zn-evoked changes of PL biosynthesis. Thus, we conducted RNA sequencing to analyze the differences in the intestinal transcriptomes between the control and Zn-treated P. fulvidraco. The 56-day Zn exposure increased the intestinal Zn accumulation, and mRNA levels of 816 genes were markedly up-regulated, while that of 263 genes were down-regulated. Many differentially expressed genes in the pathways of PL biosynthesis and protein processing in ER were identified. Their expression profiles indicated that waterborne Zn exposure injured protein metabolism, induced PL biosynthesis caused oxidative stress and ER stress, and activated the unfolded protein response. Then, using the primary enterocytes, we identified the mechanism of oxidative and ER stress mediating Zn-induced PL biosynthesis, and indicated that the activation of these pathways constituted adaptive mechanisms to reduce Zn toxicity. Our study demonstrated that Zn exposure via the water increased Zn accumulation and PL biosynthesis, and that oxidative stress and ER stress were interdependent and mediated the Zn-induced PL biosynthesis of the intestine in the freshwater teleost.
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Affiliation(s)
- Kun Wu
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College , Huazhong Agricultural University , Wuhan 430070 , China
| | - Zhi Luo
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College , Huazhong Agricultural University , Wuhan 430070 , China
- Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province , Changde 415000 , China
| | - Christer Hogstrand
- Diabetes and Nutritional Sciences Division , School of Medicine, King's College London , Franklin-Wilkins Building, 150 Stamford Street , London , SE1 9NH , U.K
| | - Guang-Hui Chen
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College , Huazhong Agricultural University , Wuhan 430070 , China
| | - Chuan-Chuan Wei
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College , Huazhong Agricultural University , Wuhan 430070 , China
| | - Dan-Dan Li
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College , Huazhong Agricultural University , Wuhan 430070 , China
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18
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Heterologous expression of CTP:phosphocholine cytidylyltransferase from Plasmodium falciparum rescues Chinese Hamster Ovary cells deficient in the Kennedy phosphatidylcholine biosynthesis pathway. Sci Rep 2018; 8:8932. [PMID: 29895950 PMCID: PMC5997628 DOI: 10.1038/s41598-018-27183-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 04/23/2018] [Indexed: 01/10/2023] Open
Abstract
The plasmodial CTP:phosphocholine cytidylyltransferase (PfCCT) is a promising antimalarial target, which can be inhibited to exploit the need for increased lipid biosynthesis during the erythrocytic life stage of Plasmodium falciparum. Notable structural and regulatory differences of plasmodial and mammalian CCTs offer the possibility to develop species-specific inhibitors. The aim of this study was to use CHO-MT58 cells expressing a temperature-sensitive mutant CCT for the functional characterization of PfCCT. We show that heterologous expression of wild type PfCCT restores the viability of CHO-MT58 cells at non-permissive (40 °C) temperatures, whereas catalytically perturbed or structurally destabilized PfCCT variants fail to provide rescue. Detailed in vitro characterization indicates that the H630N mutation diminishes the catalytic rate constant of PfCCT. The flow cytometry-based rescue assay provides a quantitative readout of the PfCCT function opening the possibility for the functional analysis of PfCCT and the high throughput screening of antimalarial compounds targeting plasmodial CCT.
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19
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Snider SA, Margison KD, Ghorbani P, LeBlond ND, O'Dwyer C, Nunes JRC, Nguyen T, Xu H, Bennett SAL, Fullerton MD. Choline transport links macrophage phospholipid metabolism and inflammation. J Biol Chem 2018; 293:11600-11611. [PMID: 29880645 DOI: 10.1074/jbc.ra118.003180] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/29/2018] [Indexed: 12/21/2022] Open
Abstract
Choline is an essential nutrient that is required for synthesis of the main eukaryote phospholipid, phosphatidylcholine. Macrophages are innate immune cells that survey and respond to danger and damage signals. Although it is well-known that energy metabolism can dictate macrophage function, little is known as to the importance of choline homeostasis in macrophage biology. We hypothesized that the uptake and metabolism of choline are important for macrophage inflammation. Polarization of primary bone marrow macrophages with lipopolysaccharide (LPS) resulted in an increased rate of choline uptake and higher levels of PC synthesis. This was attributed to a substantial increase in the transcript and protein expression of the choline transporter-like protein-1 (CTL1) in polarized cells. We next sought to determine the importance of choline uptake and CTL1 for macrophage immune responsiveness. Chronic pharmacological or CTL1 antibody-mediated inhibition of choline uptake resulted in altered cytokine secretion in response to LPS, which was associated with increased levels of diacylglycerol and activation of protein kinase C. These experiments establish a previously unappreciated link between choline phospholipid metabolism and macrophage immune responsiveness, highlighting a critical and regulatory role for macrophage choline uptake via the CTL1 transporter.
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Affiliation(s)
- Shayne A Snider
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Kaitlyn D Margison
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Peyman Ghorbani
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Nicholas D LeBlond
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Conor O'Dwyer
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Julia R C Nunes
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Thao Nguyen
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; the Ottawa Institute of Systems Biology and University of Ottawa Brain and Mind Institute, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Hongbin Xu
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; the Ottawa Institute of Systems Biology and University of Ottawa Brain and Mind Institute, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Steffany A L Bennett
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; the Ottawa Institute of Systems Biology and University of Ottawa Brain and Mind Institute, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Morgan D Fullerton
- University of Ottawa Centre for Infection, Immunity, and Inflammation and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
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20
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Membrane glycerolipid equilibrium under endoplasmic reticulum stress in Arabidopsis thaliana. Biochem Biophys Res Commun 2018. [PMID: 29524407 DOI: 10.1016/j.bbrc.2018.03.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Endoplasmic reticulum (ER) is an indispensable organelle for secretory protein synthesis as well as metabolism of phospholipids and their derivatives in eukaryotic cells. Various external and internal factors may cause an accumulation of aberrant proteins in the ER, which causes ER stress and activates cellular ER stress responses to cope with the stress. In animal research, molecular mechanisms for protein quality control upon ER stress are well documented; however, how cells maintain lipid homeostasis under ER stress is an emerging issue. The ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE), two major phospholipid classes, is important under ER stress in animal cells. However, in seed plants, no study has reported on the changes in membrane lipid content under ER stress, although a number of physiologically important environmental stresses, such as heat and salinity, induce ER stress. Here, we investigated membrane glycerolipid metabolism under ER stress in Arabidopsis. ER stress transcriptionally affected PC and PE biosynthesis pathways differentially, with no significant changes in membrane glycerolipid content. Our results suggest that higher plants maintain membrane lipid equilibrium during active transcription of phospholipid biosynthetic genes under ER stress.
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21
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Mohylyak II, Chernyk YI. Functioning of glia and neurodegeneration in Drosophila melanogaster. CYTOL GENET+ 2017. [DOI: 10.3103/s0095452717030094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Jacobs RL, Jiang H, Kennelly JP, Orlicky DJ, Allen RH, Stabler SP, Maclean KN. Cystathionine beta-synthase deficiency alters hepatic phospholipid and choline metabolism: Post-translational repression of phosphatidylethanolamine N-methyltransferase is a consequence rather than a cause of liver injury in homocystinuria. Mol Genet Metab 2017; 120:325-336. [PMID: 28291718 DOI: 10.1016/j.ymgme.2017.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/27/2022]
Abstract
Classical homocystinuria (HCU) due to inactivating mutation of cystathionine β-synthase (CBS) is a poorly understood life-threatening inborn error of sulfur metabolism. A previously described cbs-/- mouse model exhibits a semi-lethal phenotype due to neonatal liver failure. The transgenic HO mouse model of HCU exhibits only mild liver injury and recapitulates multiple aspects of the disease as it occurs in humans. Disruption of the methionine cycle in HCU has the potential to impact multiple aspect of phospholipid (PL) metabolism by disruption of both the Kennedy pathway and phosphatidylethanolamine N-methyltransferase (PEMT) mediated synthesis of phosphatidylcholine (PC). Comparative metabolomic analysis of HO mouse liver revealed decreased levels of choline, and choline phosphate indicating disruption of the Kennedy pathway. Alterations in the relative levels of multiple species of PL included significant increases in PL degradation products consistent with enhanced membrane PL turnover. A significant decrease in PC containing 20:4n6 which primarily formed by the methylation of phosphatidylethanolamine to PC was consistent with decreased flux through PEMT. Hepatic expression of PEMT in both the cbs-/- and HO models is post-translationally repressed with decreased levels of PEMT protein and activity that inversely-correlates with the scale of liver injury. Failure to induce further repression of PEMT in HO mice by increased homocysteine, methionine and S-adenosylhomocysteine or depletion of glutathione combined with examination of multiple homocysteine-independent models of liver injury indicated that repression of PEMT in HCU is a consequence rather than a cause of liver injury. Collectively, our data show significant alteration of a broad range of hepatic PL and choline metabolism in HCU with the potential to contribute to multiple aspects of pathogenesis in this disease.
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Affiliation(s)
- René L Jacobs
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G2E1, Canada; Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G2E1, Canada
| | - Hua Jiang
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - John P Kennelly
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G2E1, Canada; Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G2E1, Canada
| | - David J Orlicky
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Robert H Allen
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Sally P Stabler
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kenneth N Maclean
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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Flores-Martín J, Reyna L, Ridano ME, Panzetta-Dutari GM, Genti-Raimondi S. Suppression of StarD7 promotes endoplasmic reticulum stress and induces ROS production. Free Radic Biol Med 2016; 99:286-295. [PMID: 27554972 DOI: 10.1016/j.freeradbiomed.2016.08.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 07/29/2016] [Accepted: 08/17/2016] [Indexed: 11/19/2022]
Abstract
StarD7 is an intracellular lipid transport protein identified as up-regulated in the choriocarcinoma JEG-3 cell line. StarD7 facilitates the delivery of phosphatidylcholine (PC) to the mitochondria, and StarD7 knockdown causes a reduction in phospholipid synthesis. Since inhibition of PC synthesis may lead to endoplasmic reticulum (ER) stress we hypothesized that StarD7 may be involved in maintaining cell homeostasis. Here, we examined the effect of StarD7 silencing on ER stress response and on the levels of reactive oxygen species (ROS) in the human hepatoma cell line HepG2. StarD7 knockdown induced alterations in mitochondria and ER morphology. These changes were accompanied with an ER stress response as determined by increased expression of inositol-requiring enzyme 1α (IRE1α), calnexin, glucose regulated protein 78/immunoglobulin heavy chain-binding protein (Grp78/BiP), protein kinase-like ER kinase (PERK) as well as the phosphorylated eukaryotic translation initiation factor 2, subunit 1α (p-eIF2α). Additionally, a downregulation of the tumor suppressor p53 by a degradation mechanism was observed in StarD7 siRNA cells. Furthermore, StarD7 silencing induced ROS generation and reduced cell viability after H2O2 exposure. Decreased expression of StarD7 was associated to increased levels of the heme oxygenase-1 (HO-1) and catalase enzymes as well as in catalase enzymatic activity. Finally, no changes in levels of autophagy and apoptosis markers were observed in StarD7 siRNA treated cells respect to control cells. Taken together, these results indicate that StarD7 contributes to modulate cellular redox homeostasis.
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Affiliation(s)
- Jésica Flores-Martín
- Universidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Químicas, Departamento de Bioquímica Clínica-Centro de Investigaciones en Bioquímica Clínica e Inmunología, Haya de la Torre y Medina Allende, X5000HUA Córdoba, Argentina
| | - Luciana Reyna
- Universidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Químicas, Departamento de Bioquímica Clínica-Centro de Investigaciones en Bioquímica Clínica e Inmunología, Haya de la Torre y Medina Allende, X5000HUA Córdoba, Argentina
| | - Magali E Ridano
- Universidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Químicas, Departamento de Bioquímica Clínica-Centro de Investigaciones en Bioquímica Clínica e Inmunología, Haya de la Torre y Medina Allende, X5000HUA Córdoba, Argentina
| | - Graciela M Panzetta-Dutari
- Universidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Químicas, Departamento de Bioquímica Clínica-Centro de Investigaciones en Bioquímica Clínica e Inmunología, Haya de la Torre y Medina Allende, X5000HUA Córdoba, Argentina
| | - Susana Genti-Raimondi
- Universidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Químicas, Departamento de Bioquímica Clínica-Centro de Investigaciones en Bioquímica Clínica e Inmunología, Haya de la Torre y Medina Allende, X5000HUA Córdoba, Argentina.
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Alkyl ether lipids, ion channels and lipid raft reorganization in cancer therapy. Pharmacol Ther 2016; 165:114-31. [DOI: 10.1016/j.pharmthera.2016.06.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 05/26/2016] [Indexed: 12/21/2022]
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Phosphatidylcholine as a metabolic cue for determining B cell fate and function. Cell Immunol 2016; 310:78-88. [PMID: 27502364 DOI: 10.1016/j.cellimm.2016.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 07/27/2016] [Accepted: 08/02/2016] [Indexed: 01/14/2023]
Abstract
In activated B cells, increased production of phosphatidylcholine (PtdCho), the most abundant cellular phospholipid, is handled primarily by the CDP-choline pathway. B cell-specific deletion of CTP:phosphocholine cytidylyltransferase α (CCTα), the rate-limiting enzyme in the CDP-choline pathway, led to augmented IgM secretion and reduced IgG production, suggesting that PtdCho synthesis is required for germinal center reactions. To specifically assess whether PtdCho influences B cell fate during germinal center responses, we examined immune responses in mice whereby PtdCho synthesis is disrupted in B cells that have undergone class switch recombination to IgG1 (referred to as either Cγ1wt/wt, Cγ1Cre/wt or Cγ1Cre/Cre based on Cre copy number). Serum IgG1 was markedly reduced in naïve Cγ1Cre/wt and Cγ1Cre/Cre mice, while levels of IgM and other IgG subclasses were similar between Cγ1Cre/wt and Cγ1wt/wt control mice. Serum IgG2b titers were notably reduced and IgG3 titers were increased in Cγ1Cre/Cre mice compared with controls. Following immunization with T cell-dependent antigen NP-KLH, control mice generated high titer IgG anti-NP while IgG anti-NP titers were markedly reduced in both immunized Cγ1Cre/wt and Cγ1Cre/Cre mice. Correspondingly, the frequency of NP-specific IgG antibody-secreting cells was also reduced in spleens and bone marrow of Cγ1Cre/wt and Cγ. 1Cre/Cre mice compared to control mice. Interestingly, though antigen-specific IgM B cells were comparable between Cγ1Cre/wt, Cγ1Cre/Cre and control mice, the frequency and number of IgG1 NP-specific B cells was reduced only in Cγ1Cre/Cre mice. These data indicate that PtdCho is required for the generation of both germinal center-derived B cells and antibody-secreting cells. Further, the reduction in class-switched ASC but not B cells in Cγ1Cre/wt mice suggests that ASC have a greater demand for PtdCho compared to germinal center B cells.
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Trousil S, Kaliszczak M, Schug Z, Nguyen QD, Tomasi G, Favicchio R, Brickute D, Fortt R, Twyman FJ, Carroll L, Kalusa A, Navaratnam N, Adejumo T, Carling D, Gottlieb E, Aboagye EO. The novel choline kinase inhibitor ICL-CCIC-0019 reprograms cellular metabolism and inhibits cancer cell growth. Oncotarget 2016; 7:37103-37120. [PMID: 27206796 PMCID: PMC5095062 DOI: 10.18632/oncotarget.9466] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 04/25/2016] [Indexed: 12/25/2022] Open
Abstract
The glycerophospholipid phosphatidylcholine is the most abundant phospholipid species of eukaryotic membranes and essential for structural integrity and signaling function of cell membranes required for cancer cell growth. Inhibition of choline kinase alpha (CHKA), the first committed step to phosphatidylcholine synthesis, by the selective small-molecule ICL-CCIC-0019, potently suppressed growth of a panel of 60 cancer cell lines with median GI50 of 1.12 μM and inhibited tumor xenograft growth in mice. ICL-CCIC-0019 decreased phosphocholine levels and the fraction of labeled choline in lipids, and induced G1 arrest, endoplasmic reticulum stress and apoptosis. Changes in phosphocholine cellular levels following treatment could be detected non-invasively in tumor xenografts by [18F]-fluoromethyl-[1,2-2H4]-choline positron emission tomography. Herein, we reveal a previously unappreciated effect of choline metabolism on mitochondria function. Comparative metabolomics demonstrated that phosphatidylcholine pathway inhibition leads to a metabolically stressed phenotype analogous to mitochondria toxin treatment but without reactive oxygen species activation. Drug treatment decreased mitochondria function with associated reduction of citrate synthase expression and AMPK activation. Glucose and acetate uptake were increased in an attempt to overcome the metabolic stress. This study indicates that choline pathway pharmacological inhibition critically affects the metabolic function of the cell beyond reduced synthesis of phospholipids.
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Affiliation(s)
- Sebastian Trousil
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Maciej Kaliszczak
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Zachary Schug
- Cancer Research UK, Beatson Institute, Garscube Estate, Glasgow, UK
| | - Quang-De Nguyen
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Giampaolo Tomasi
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Rosy Favicchio
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Diana Brickute
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Robin Fortt
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Frazer J. Twyman
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Laurence Carroll
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Andrew Kalusa
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Naveenan Navaratnam
- Cellular Stress Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, London, UK
| | - Thomas Adejumo
- Cellular Stress Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, London, UK
| | - David Carling
- Cellular Stress Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, London, UK
| | - Eyal Gottlieb
- Cancer Research UK, Beatson Institute, Garscube Estate, Glasgow, UK
| | - Eric O. Aboagye
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
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Knockdown of triglyceride synthesis does not enhance palmitate lipotoxicity or prevent oleate-mediated rescue in rat hepatocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1005-1014. [PMID: 27249207 DOI: 10.1016/j.bbalip.2016.05.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 05/14/2016] [Accepted: 05/26/2016] [Indexed: 12/14/2022]
Abstract
Experiments in a variety of cell types, including hepatocytes, consistently demonstrate the acutely lipotoxic effects of saturated fatty acids, such as palmitate (PA), but not unsaturated fatty acids, such as oleate (OA). PA+OA co-treatment fully prevents PA lipotoxicity through mechanisms that are not well defined but which have been previously attributed to more efficient esterification and sequestration of PA into triglycerides (TGs) when OA is abundant. However, this hypothesis has never been directly tested by experimentally modulating the relative partitioning of PA/OA between TGs and other lipid fates in hepatocytes. In this study, we found that addition of OA to PA-treated hepatocytes enhanced TG synthesis, reduced total PA uptake and PA lipid incorporation, decreased phospholipid saturation and rescued PA-induced ER stress and lipoapoptosis. Knockdown of diacylglycerol acyltransferase (DGAT), the rate-limiting step in TG synthesis, significantly reduced TG accumulation without impairing OA-mediated rescue of PA lipotoxicity. In both wild-type and DGAT-knockdown hepatocytes, OA co-treatment significantly reduced PA lipid incorporation and overall phospholipid saturation compared to PA-treated hepatocytes. These data indicate that OA's protective effects do not require increased conversion of PA into inert TGs, but instead may be due to OA's ability to compete against PA for cellular uptake and/or esterification and, thereby, normalize the composition of cellular lipids in the presence of a toxic PA load.
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Wang Y, Tian J, Qiao X, Su X, Mi Y, Zhang R, Li R. Intermedin protects against renal ischemia-reperfusion injury by inhibiting endoplasmic reticulum stress. BMC Nephrol 2015; 16:169. [PMID: 26498843 PMCID: PMC4619099 DOI: 10.1186/s12882-015-0157-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/02/2015] [Indexed: 11/15/2022] Open
Abstract
Background Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide family. Endoplasmic reticulum stress (ERS) has been implicated in the pathology of renal ischemia/reperfusion (IRI). In the present study, we investigated whether IMD could reduce ERS damage after renal ischemia. Methods The kidneys of SD rats were subjected to 45 min of warm ischemia followed by 24 h of reperfusion. The hypoxia/reoxygenation(H/R) model in NRK-52E cells consisted of hypoxia for 1 h and reoxygenation for 2 h. IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. The serum creatinine concentration and lactate dehydrogenase (LDH) activity in the plasma were determined. Histologic examinations of renal tissues were performed with PAS staining. Real-time PCR and Western blotting were used to determine the mRNA and protein levels, respectively. Additionally, ER staining was used to detect the ERS response. Results In the rat renal IRI model, we found that IMD gene transfer markedly improved renal function and pathology and decreased LDH activity and cell apoptosis compared with the kidneys that were transfected with the control plasmid. IMD significantly attenuated the ERS stress parameters compared with IRI group. Indeed, IMD down-regulated glucose-regulated protein 78 (GRP78), C/EBP homologous protein(CHOP), and caspase 12 protein and mRNA levels. Moreover, in the NRK-52E cell H/R model, IMD overexpression prevented the apoptosis induced by H/R. Furthermore, IMD ameliorated the ER structural changes and concomitantly decreased the levels of GRP78, CHOP and caspase-12. Conclusion This study revealed that IMD protects against renal IRI by suppressing ERS and ERS-related apoptosis.
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Affiliation(s)
- Yanhong Wang
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Jihua Tian
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Xi Qiao
- Department of Nephrology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Xiaole Su
- Department of Nephrology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Yang Mi
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Ruijing Zhang
- Department of Nephrology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China.
| | - Rongshan Li
- Department of Nephrology, the Affiliated People's Hospital of Shanxi Medical University, Shanxi Provincial People's Hospital, Shanxi Kidney Disease Institute, No. 29 Shuang Ta East Street, Taiyuan, 030012, , Shanxi, P. R. China.
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Experimental study of the protective effects of SYVN1 against diabetic retinopathy. Sci Rep 2015; 5:14036. [PMID: 26358086 PMCID: PMC4642554 DOI: 10.1038/srep14036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/13/2015] [Indexed: 12/15/2022] Open
Abstract
Genetic factors play an important role in the pathogenesis of diabetic retinopathy (DR). While many studies have focused on genes that increase susceptibility to DR, herein, we aimed to explore genes that confer DR resistance. Previously, we identified Hmg CoA reductase degradation protein 1 (SYVN1) as a putative DR protective gene via gene expression analysis. Transgenic mice overexpressing SYVN1 and wild-type (WT) mice with streptozotocin-induced diabetes were used in this experiment. Retinal damage and vascular leakage were investigated 6 months after induction of diabetes by histopathological and retinal cell apoptosis analyses and by retinal perfusion of fluorescein isothiocyanate-conjugated dextran. Compared with diabetic WT mice, diabetic SYVN1 mice had significantly more cells and reduced apoptosis in the retinal ganglion layer. Retinal vascular leakage was significantly lower in diabetic SYVN1 mice than in diabetic WT mice. The expression levels of endoplasmic reticulum (ER) stress-related, pro-inflammatory, and pro-angiogenic genes were also analyzed. Lower expression levels were observed in diabetic SYVN1 mice than in WT controls, suggesting that SYVN1 may play an important role in inhibiting ER stress, chronic inflammation, and vascular overgrowth associated with DR. Thus, these results strongly supported our hypothesis that SYVN1 confers DR resistance.
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Kanehara K, Yu CY, Cho Y, Cheong WF, Torta F, Shui G, Wenk MR, Nakamura Y. Arabidopsis AtPLC2 Is a Primary Phosphoinositide-Specific Phospholipase C in Phosphoinositide Metabolism and the Endoplasmic Reticulum Stress Response. PLoS Genet 2015; 11:e1005511. [PMID: 26401841 PMCID: PMC4581737 DOI: 10.1371/journal.pgen.1005511] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/17/2015] [Indexed: 01/18/2023] Open
Abstract
Phosphoinositides represent important lipid signals in the plant development and stress response. However, multiple isoforms of the phosphoinositide biosynthetic genes hamper our understanding of the pivotal enzymes in each step of the pathway as well as their roles in plant growth and development. Here, we report that phosphoinositide-specific phospholipase C2 (AtPLC2) is the primary phospholipase in phosphoinositide metabolism and is involved in seedling growth and the endoplasmic reticulum (ER) stress responses in Arabidopsis thaliana. Lipidomic profiling of multiple plc mutants showed that the plc2-1 mutant increased levels of its substrates phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, suggesting that the major phosphoinositide metabolic pathway is impaired. AtPLC2 displayed a distinct tissue expression pattern and localized at the plasma membrane in different cell types, where phosphoinositide signaling occurs. The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth. Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles. Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.
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Affiliation(s)
- Kazue Kanehara
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan
- Muroran Institute of Technology, Muroran, Japan
| | - Chao-Yuan Yu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yueh Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan
| | - Wei-Fun Cheong
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Federico Torta
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Guanghou Shui
- Life Sciences Institute, National University of Singapore, Singapore
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Yuki Nakamura
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan
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Marton L, Nagy GN, Ozohanics O, Lábas A, Krámos B, Oláh J, Vékey K, Vértessy BG. Molecular Mechanism for the Thermo-Sensitive Phenotype of CHO-MT58 Cell Line Harbouring a Mutant CTP:Phosphocholine Cytidylyltransferase. PLoS One 2015; 10:e0129632. [PMID: 26083347 PMCID: PMC4470507 DOI: 10.1371/journal.pone.0129632] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 05/10/2015] [Indexed: 01/27/2023] Open
Abstract
Control and elimination of malaria still represents a major public health challenge. Emerging parasite resistance to current therapies urges development of antimalarials with novel mechanism of action. Phospholipid biosynthesis of the Plasmodium parasite has been validated as promising candidate antimalarial target. The most prevalent de novo pathway for synthesis of phosphatidylcholine is the Kennedy pathway. Its regulatory and often also rate limiting step is catalyzed by CTP:phosphocholine cytidylyltransferase (CCT). The CHO-MT58 cell line expresses a mutant variant of CCT, and displays a thermo-sensitive phenotype. At non-permissive temperature (40°C), the endogenous CCT activity decreases dramatically, blocking membrane synthesis and ultimately leading to apoptosis. In the present study we investigated the impact of the analogous mutation in a catalytic domain construct of Plasmodium falciparum CCT in order to explore the underlying molecular mechanism that explains this phenotype. We used temperature dependent enzyme activity measurements and modeling to investigate the functionality of the mutant enzyme. Furthermore, MS measurements were performed to determine the oligomerization state of the protein, and MD simulations to assess the inter-subunit interactions in the dimer. Our results demonstrate that the R681H mutation does not directly influence enzyme catalytic activity. Instead, it provokes increased heat-sensitivity by destabilizing the CCT dimer. This can possibly explain the significance of the PfCCT pseudoheterodimer organization in ensuring proper enzymatic function. This also provide an explanation for the observed thermo-sensitive phenotype of CHO-MT58 cell line.
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Affiliation(s)
- Lívia Marton
- Institute of Enzymology, Research Centre for National Sciences, HAS, Budapest Hungary
- Doctoral School of Multidisciplinary Medical Science, University of Szeged, Szeged, Hungary
| | - Gergely N. Nagy
- Institute of Enzymology, Research Centre for National Sciences, HAS, Budapest Hungary
- Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest, Hungary
| | - Olivér Ozohanics
- Institute of Organic Chemistry, Research Centre for National Sciences, HAS, Budapest, Hungary
| | - Anikó Lábas
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Budapest, Hungary
| | - Balázs Krámos
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Budapest, Hungary
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Budapest, Hungary
| | - Károly Vékey
- Institute of Organic Chemistry, Research Centre for National Sciences, HAS, Budapest, Hungary
| | - Beáta G. Vértessy
- Institute of Enzymology, Research Centre for National Sciences, HAS, Budapest Hungary
- Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest, Hungary
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Heberle AM, Prentzell MT, van Eunen K, Bakker BM, Grellscheid SN, Thedieck K. Molecular mechanisms of mTOR regulation by stress. Mol Cell Oncol 2015; 2:e970489. [PMID: 27308421 PMCID: PMC4904989 DOI: 10.4161/23723548.2014.970489] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 09/12/2014] [Accepted: 09/13/2014] [Indexed: 04/12/2023]
Abstract
Tumors are prime examples of cell growth in unfavorable environments that elicit cellular stress. The high metabolic demand and insufficient vascularization of tumors cause a deficiency of oxygen and nutrients. Oncogenic mutations map to signaling events via mammalian target of rapamycin (mTOR), metabolic pathways, and mitochondrial function. These alterations have been linked with cellular stresses, in particular endoplasmic reticulum (ER) stress, hypoxia, and oxidative stress. Yet tumors survive these challenges and acquire highly energy-demanding traits, such as overgrowth and invasiveness. In this review we focus on stresses that occur in cancer cells and discuss them in the context of mTOR signaling. Of note, many tumor traits require mTOR complex 1 (mTORC1) activity, but mTORC1 hyperactivation eventually sensitizes cells to apoptosis. Thus, mTORC1 activity needs to be balanced in cancer cells. We provide an overview of the mechanisms contributing to mTOR regulation by stress and suggest a model wherein stress granules function as guardians of mTORC1 signaling, allowing cancer cells to escape stress-induced cell death.
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Affiliation(s)
- Alexander Martin Heberle
- Department of Pediatrics and Centre for Systems Biology of Energy Metabolism and Ageing; University of Groningen; University Medical Center Groningen (UMCG); Groningen, The Netherlands
| | - Mirja Tamara Prentzell
- Department of Pediatrics and Centre for Systems Biology of Energy Metabolism and Ageing; University of Groningen; University Medical Center Groningen (UMCG); Groningen, The Netherlands
- Faculty of Biology; Institute for Biology 3; Albert-Ludwigs-University Freiburg; Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM); University of Freiburg; Freiburg, Germany
| | - Karen van Eunen
- Department of Pediatrics and Centre for Systems Biology of Energy Metabolism and Ageing; University of Groningen; University Medical Center Groningen (UMCG); Groningen, The Netherlands
- Top Institute Food and Nutrition; Wageningen, The Netherlands
| | - Barbara Marleen Bakker
- Department of Pediatrics and Centre for Systems Biology of Energy Metabolism and Ageing; University of Groningen; University Medical Center Groningen (UMCG); Groningen, The Netherlands
| | | | - Kathrin Thedieck
- Department of Pediatrics and Centre for Systems Biology of Energy Metabolism and Ageing; University of Groningen; University Medical Center Groningen (UMCG); Groningen, The Netherlands
- Faculty of Biology; Institute for Biology 3; Albert-Ludwigs-University Freiburg; Freiburg, Germany
- School of Medicine and Health Sciences; Carl von Ossietzky University Oldenburg; Oldenburg, Germany
- BIOSS Centre for Biological Signaling Studies; Albert-Ludwigs-University Freiburg; Freiburg, Germany
- Correspondence to: Kathrin Thedieck; E-mail: ;
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Misra UK, Pizzo SV. Activated α2-macroglobulin binding to human prostate cancer cells triggers insulin-like responses. J Biol Chem 2015; 290:9571-87. [PMID: 25720493 DOI: 10.1074/jbc.m114.617837] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Indexed: 12/21/2022] Open
Abstract
Ligation of cell surface GRP78 by activated α2-macroglobulin (α2M*) promotes cell proliferation and suppresses apoptosis. α2M*-treated human prostate cancer cells exhibit a 2-3-fold increase in glucose uptake and lactate secretion, an effect similar to insulin treatment. In both α2M* and insulin-treated cells, the mRNA levels of SREBP1-c, SREBP2, fatty-acid synthase, acetyl-CoA carboxylase, ATP citrate lyase, and Glut-1 were significantly increased together with their protein levels, except for SREBP2. Pretreatment of cells with α2M* antagonist antibody directed against the carboxyl-terminal domain of GRP78 blocks these α2M*-mediated effects, and silencing GRP78 expression by RNAi inhibits up-regulation of ATP citrate lyase and fatty-acid synthase. α2M* induces a 2-3-fold increase in lipogenesis as determined by 6-[(14)C]glucose or 1-[(14)C]acetate incorporation into free cholesterol, cholesterol esters, triglycerides, free fatty acids, and phosphatidylcholine, which is blocked by inhibitors of fatty-acid synthase, PI 3-kinase, mTORC, or an antibody against the carboxyl-terminal domain of GRP78. We also assessed the incorporation of [(14)CH3]choline into phosphatidylcholine and observed similar effects. Lipogenesis is significantly affected by pretreatment of prostate cancer cells with fatostatin A, which blocks sterol regulatory element-binding protein proteolytic cleavage and activation. This study demonstrates that α2M* functions as a growth factor, leading to proliferation of prostate cancer cells by promoting insulin-like responses. An antibody against the carboxyl-terminal domain of GRP78 may have important applications in prostate cancer therapy.
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Affiliation(s)
- Uma Kant Misra
- From the Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Salvatore Vincent Pizzo
- From the Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
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Murray M, Hraiki A, Bebawy M, Pazderka C, Rawling T. Anti-tumor activities of lipids and lipid analogues and their development as potential anticancer drugs. Pharmacol Ther 2015; 150:109-28. [PMID: 25603423 DOI: 10.1016/j.pharmthera.2015.01.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/09/2015] [Indexed: 12/28/2022]
Abstract
Lipids have the potential for development as anticancer agents. Endogenous membrane lipids, such as ceramides and certain saturated fatty acids, have been found to modulate the viability of tumor cells. In addition, many tumors over-express cyclooxygenase, lipoxygenase or cytochrome P450 enzymes that mediate the biotransformation of ω-6 polyunsaturated fatty acids (PUFAs) to potent eicosanoid regulators of tumor cell proliferation and cell death. In contrast, several analogous products from the biotransformation of ω-3 PUFAs impair particular tumorigenic pathways. For example, the ω-3 17,18-epoxide of eicosapentaenoic acid activates anti-proliferative and proapoptotic signaling cascades in tumor cells and the lipoxygenase-derived resolvins are effective inhibitors of inflammatory pathways that may drive tumor expansion. However, the development of potential anti-cancer drugs based on these molecules is complex, with in vivo stability a major issue. Nevertheless, recent successes with the antitumor alkyl phospholipids, which are synthetic analogues of naturally-occurring membrane phospholipid esters, have provided the impetus for development of further molecules. The alkyl phospholipids have been tested against a range of cancers and show considerable activity against skin cancers and certain leukemias. Very recently, it has been shown that combination strategies, in which alkyl phospholipids are used in conjunction with established anticancer agents, are promising new therapeutic approaches. In future, the evaluation of new lipid-based molecules in single-agent and combination treatments may also be assessed. This could provide a range of important treatment options in the management of advanced and metastatic cancer.
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Affiliation(s)
- Michael Murray
- Pharmacogenomics and Drug Development Group, Discipline of Pharmacology, School of Medical Sciences, Sydney Medical School, University of Sydney, NSW 2006, Australia.
| | - Adam Hraiki
- Pharmacogenomics and Drug Development Group, Discipline of Pharmacology, School of Medical Sciences, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - Mary Bebawy
- Discipline of Pharmacy, Graduate School of Health, University of Technology, Ultimo, NSW 2007, Australia
| | - Curtis Pazderka
- Discipline of Pharmacy, Graduate School of Health, University of Technology, Ultimo, NSW 2007, Australia
| | - Tristan Rawling
- Discipline of Pharmacy, Graduate School of Health, University of Technology, Ultimo, NSW 2007, Australia
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Fung TS, Huang M, Liu DX. Coronavirus-induced ER stress response and its involvement in regulation of coronavirus-host interactions. Virus Res 2014; 194:110-23. [PMID: 25304691 PMCID: PMC7114476 DOI: 10.1016/j.virusres.2014.09.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/25/2014] [Accepted: 09/28/2014] [Indexed: 12/11/2022]
Abstract
Coronavirus replication is structurally and functionally associated with the endoplasmic reticulum (ER), a major site of protein synthesis, folding, modification and sorting in the eukaryotic cells. Disturbance of ER homeostasis may occur under various physiological or pathological conditions. In response to the ER stress, signaling pathways of the unfolded protein response (UPR) are activated. UPR is mediated by three ER transmembrane sensors, namely the PKR-like ER protein kinase (PERK), the inositol-requiring protein 1 (IRE1) and the activating transcriptional factor 6 (ATF6). UPR facilitates adaptation to ER stress by reversible translation attenuation, enhancement of ER protein folding capacity and activation of ER-associated degradation (ERAD). In cells under prolonged and irremediable ER stress, UPR can also trigger apoptotic cell death. Accumulating evidence has shown that coronavirus infection causes ER stress and induces UPR in the infected cells. UPR is closely associated with a number of major signaling pathways, including autophagy, apoptosis, the mitogen-activated protein (MAP) kinase pathways, innate immunity and pro-inflammatory response. Therefore, studies on the UPR are pivotal in elucidating the complicated issue of coronavirus-host interaction. In this paper, we present the up-to-date knowledge on coronavirus-induced UPR and discuss its potential involvement in regulation of innate immunity and apoptosis.
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Affiliation(s)
- To Sing Fung
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Mei Huang
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Ding Xiang Liu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551.
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Leamy AK, Egnatchik RA, Shiota M, Ivanova PT, Myers DS, Brown HA, Young JD. Enhanced synthesis of saturated phospholipids is associated with ER stress and lipotoxicity in palmitate treated hepatic cells. J Lipid Res 2014; 55:1478-88. [PMID: 24859739 DOI: 10.1194/jlr.m050237] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Indexed: 01/22/2023] Open
Abstract
High levels of saturated FAs (SFAs) are acutely toxic to a variety of cell types, including hepatocytes, and have been associated with diseases such as type 2 diabetes and nonalcoholic fatty liver disease. SFA accumulation has been previously shown to degrade endoplasmic reticulum (ER) function leading to other manifestations of the lipoapoptotic cascade. We hypothesized that dysfunctional phospholipid (PL) metabolism is an initiating factor in this ER stress response. Treatment of either primary hepatocytes or H4IIEC3 cells with the SFA palmitate resulted in dramatic dilation of the ER membrane, coinciding with other markers of organelle dysfunction. This was accompanied by increased de novo glycerolipid synthesis, significant elevation of dipalmitoyl phosphatidic acid, diacylglycerol, and total PL content in H4IIEC3 cells. Supplementation with oleate (OA) reversed these markers of palmitate (PA)-induced lipotoxicity. OA/PA cotreatment modulated the distribution of PA between lipid classes, increasing the flux toward triacylglycerols while reducing its incorporation into PLs. Similar trends were demonstrated in both primary hepatocytes and the H4IIEC3 hepatoma cell line. Overall, these findings suggest that modifying the FA composition of structural PLs can protect hepatocytes from PA-induced ER stress and associated lipotoxicity.
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Affiliation(s)
- Alexandra K Leamy
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604
| | - Robert A Egnatchik
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235-1604
| | - Pavlina T Ivanova
- Department of Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235-1604
| | - David S Myers
- Department of Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235-1604
| | - H Alex Brown
- Department of Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235-1604 Department of Biochemistry, Vanderbilt University, Nashville, TN 37235-1604 Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235-1604
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604 Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235-1604
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Sanchez-Lopez E, Zimmerman T, Gomez del Pulgar T, Moyer MP, Lacal Sanjuan JC, Cebrian A. Choline kinase inhibition induces exacerbated endoplasmic reticulum stress and triggers apoptosis via CHOP in cancer cells. Cell Death Dis 2013; 4:e933. [PMID: 24287694 PMCID: PMC3847329 DOI: 10.1038/cddis.2013.453] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/06/2013] [Accepted: 10/14/2013] [Indexed: 11/09/2022]
Abstract
Endoplasmic reticulum (ER) is a central organelle in eukaryotic cells that regulates protein synthesis and maturation. Perturbation of ER functions leads to ER stress, which has been previously associated with a broad variety of diseases. ER stress is generally regarded as compensatory, but prolonged ER stress has been involved in apoptosis induced by several cytotoxic agents. Choline kinase α (ChoKα), the first enzyme in the Kennedy pathway, is responsible for the generation of phosphorylcholine (PCho) that ultimately renders phosphatidylcholine. ChoKα overexpression and high PCho levels have been detected in several cancer types. Inhibition of ChoKα has demonstrated antiproliferative and antitumor properties; however, the mechanisms underlying these activities remain poorly understood. Here, we demonstrate that ChoKα inhibitors (ChoKIs), MN58b and RSM932A, induce cell death in cancer cells (T47D, MCF7, MDA-MB231, SW620 and H460), through the prolonged activation of ER stress response. Evidence of ChoKIs-induced ER stress includes enhanced production of glucose-regulated protein, 78 kDa (GRP78), protein disulfide isomerase, IRE1α, CHOP, CCAAT/enhancer-binding protein beta (C/EBPβ) and TRB3. Although partial reduction of ChoKα levels by small interfering RNA was not sufficient to increase the production of ER stress proteins, silencing of ChoKα levels also show a decrease in CHOP overproduction induced by ChoKIs, which suggests that ER stress induction is due to a change in ChoKα protein folding after binding to ChoKIs. Silencing of CHOP expression leads to a reduction in C/EBPβ, ATF3 and GRP78 protein levels and abrogates apoptosis in tumor cells after treatment with ChoKIs, suggesting that CHOP maintains ER stress responses and triggers the pro-apoptotic signal. Consistent with the differential effect of ChoKIs in cancer and primary cells previously described, ChoKIs only promoted a transient and moderated ER stress response in the non-tumorogenic cells MCF10A. In conclusion, pharmacological inhibition of ChoKα induces cancer cell death through a mechanism that involves the activation of exaggerated and persistent ER stress supported by CHOP overproduction.
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Affiliation(s)
- E Sanchez-Lopez
- Department of Pharmacology, School of Medicine, UCSD, San Diego, CA, USA
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Ambrose RL, Mackenzie JM. Flaviviral regulation of the unfolded protein response: can stress be beneficial? Future Virol 2013. [DOI: 10.2217/fvl.13.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Members of the Flaviviridae family remain some of the most significant human viral pathogens, with few vaccines or antivirals commercially available for therapeutic use. Thus, understanding the intracellular events of replication and how these viruses modulate signaling within an infected cell is of great importance. The ER is central to replication within the Flaviviridae family, as the site of viral protein translation and processing, as a source of membranes for replication complex formation and as a site of virus assembly. This places a large burden upon the organelle, resulting in the induction of ER stress responses, in particular the unfolded protein response. In turn, unfolded protein response signaling induced in infected cells is tightly modulated by the virus in order to maintain an optimal environment for replication. The loss of various components of the stress response can have either beneficial or detrimental effects, presenting intriguing targets for antiviral discovery.
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Affiliation(s)
- Rebecca L Ambrose
- Department of Microbiology & Immunology, University of Melbourne, Parkville, Melbourne, VIC, 3052, Australia
| | - Jason M Mackenzie
- Department of Microbiology & Immunology, University of Melbourne, Parkville, Melbourne, VIC, 3052, Australia
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Wang ZC, Wang JF, Li YB, Guo CX, Liu Y, Fang F, Gong SL. Involvement of endoplasmic reticulum stress in apoptosis of testicular cells induced by low-dose radiation. ACTA ACUST UNITED AC 2013; 33:551-558. [PMID: 23904376 DOI: 10.1007/s11596-013-1157-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 12/12/2012] [Indexed: 02/04/2023]
Abstract
The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor-6 (ATF6) in apoptosis of mouse testicular cells treated with low-dose radiation (LDR). In the dose-dependent experiment, the mice were treated with whole-body X-ray irradiation at different doses (25, 50, 75, 100 or 200 mGy) and sacrificed 12 h later. In the time-dependent experiment, the mice were exposed to 75 mGy X-ray irradiation and killed at different time points (3, 6, 12, 18 or 24 h). Testicular cells were harvested for experiments. H(2)O(2) and NO concentrations, and Ca(2+)-ATPase activity were detected by biochemical assays, the calcium ion concentration ([Ca(2+)]i) by flow cytometry using fluo-3 probe, and GRP78 mRNA and protein expressions by quantitative real-time RT-PCR (qRT-PCR) and Western blotting, respectively. The mRNA expressions of S-XBP1, JNK, caspase-12 and CHOP were measured by qRT-PCR, and the protein expressions of IRE1α, S-XBP1, p-PERK, p-eIF2α, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP by Western blotting. The results showed that the concentrations of H2O2 and NO, the mRNA expressions of GRP78, S-XBP1, JNK, caspase-12 and CHOP, and the protein expressions of GRP78, S-XBP1, IRE1α, p-PERK, p-eIF2α, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP were significantly increased in a time- and dose-dependent manner after LDR. But the [Ca(2+)]i and Ca(2+)-ATPase activities were significantly decreased in a time- and dose-dependent manner. It was concluded that the ERS, regulated by IRE1, PERK and ATF6 pathways, is involved in the apoptosis of testicular cells in LDR mice, which is associated with ERS-apoptotic signaling molecules of JNK, caspase-12 and CHOP.
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Affiliation(s)
- Zhi-Cheng Wang
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China
| | - Jian-Feng Wang
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China
| | - Yan-Bo Li
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China.,School of Public Health and Family Medicine, Capital Medical University, Beijing, 100069, China
| | - Cai-Xia Guo
- School of Public Health and Family Medicine, Capital Medical University, Beijing, 100069, China
| | - Yang Liu
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China
| | - Fang Fang
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China.
| | - Shou-Liang Gong
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China.
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Watanabe K, Watson E, Cremona ML, Millings EJ, Lefkowitch JH, Fischer SG, LeDuc CA, Leibel RL. ILDR2: an endoplasmic reticulum resident molecule mediating hepatic lipid homeostasis. PLoS One 2013; 8:e67234. [PMID: 23826244 PMCID: PMC3691114 DOI: 10.1371/journal.pone.0067234] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/15/2013] [Indexed: 11/18/2022] Open
Abstract
Ildr2, a modifier of diabetes susceptibility in obese mice, is expressed in most organs, including islets and hypothalamus, with reduced levels in livers of diabetes-susceptible B6.DBA mice congenic for a 1.8 Mb interval of Chromosome 1. In hepatoma and neuronal cells, ILDR2 is primarily located in the endoplasmic reticulum membrane. We used adenovirus vectors that express shRNA or are driven by the CMV promoter, respectively, to knockdown or overexpress Ildr2 in livers of wild type and ob/ob mice. Livers in knockdown mice were steatotic, with increased hepatic and circulating triglycerides and total cholesterol. Increased circulating VLDL, without reduction in triglyceride clearance suggests an effect of reduced hepatic ILDR2 on hepatic cholesterol clearance. In animals that overexpress Ildr2, hepatic triglyceride and total cholesterol levels were reduced, and strikingly so in ob/ob mice. There were no significant changes in body weight, energy expenditure or glucose/insulin homeostasis in knockdown or overexpressing mice. Knockdown mice showed reduced expression of genes mediating synthesis and oxidation of hepatic lipids, suggesting secondary suppression in response to increased hepatic lipid content. In Ildr2-overexpressing ob/ob mice, in association with reduced liver fat content, levels of transcripts related to neutral lipid synthesis and cholesterol were increased, suggesting “relief” of the secondary suppression imposed by lipid accumulation. Considering the fixed location of ILDR2 in the endoplasmic reticulum, we investigated the possible participation of ILDR2 in ER stress responses. In general, Ildr2 overexpression was associated with increases, and knockdown with decreases in levels of expression of molecular components of canonical ER stress pathways. We conclude that manipulation of Ildr2 expression in liver affects both lipid homeostasis and ER stress pathways. Given these reciprocal interactions, and the relatively extended time-course over which these studies were conducted, we cannot assign causal primacy to either the effects on hepatic lipid homeostasis or ER stress responses.
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Affiliation(s)
- Kazuhisa Watanabe
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Elizabeth Watson
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Maria Laura Cremona
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Elizabeth J. Millings
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Jay H. Lefkowitch
- Department of Pathology and Cell Biology, Columbia University, New York, New York, United States of America
| | - Stuart G. Fischer
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Charles A. LeDuc
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Rudolph L. Leibel
- Naomi Berrie Diabetes Center and Department of Pediatrics, Columbia University, New York, New York, United States of America
- * E-mail:
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41
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Lagace TA, Ridgway ND. The role of phospholipids in the biological activity and structure of the endoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2499-510. [PMID: 23711956 DOI: 10.1016/j.bbamcr.2013.05.018] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/09/2013] [Accepted: 05/15/2013] [Indexed: 01/22/2023]
Abstract
The endoplasmic reticulum (ER) is an interconnected network of tubular and planar membranes that supports the synthesis and export of proteins, carbohydrates and lipids. Phospholipids, in particular phosphatidylcholine (PC), are synthesized in the ER where they have essential functions including provision of membranes required for protein synthesis and export, cholesterol homeostasis, and triacylglycerol storage and secretion. Coordination of these biological processes is essential, as highlighted by findings that link phospholipid metabolism in the ER with perturbations in lipid storage/secretion and stress responses, ultimately contributing to obesity/diabetes, atherosclerosis and neurological disorders. Phospholipid synthesis is not uniformly distributed in the ER but is localized at membrane interfaces or contact zones with other organelles, and in dynamic, proliferating ER membranes. The topology of phospholipid synthesis is an important consideration when establishing the etiology of diseases that arise from ER dysfunction. This review will highlight our current understanding of the contribution of phospholipid synthesis to proper ER function, and how alterations contribute to aberrant stress responses and disease. This article is part of a Special Issue entitled: Functional and structural diversity of endoplasmic reticulum.
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Affiliation(s)
- Thomas A Lagace
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
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42
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Leamy AK, Egnatchik RA, Young JD. Molecular mechanisms and the role of saturated fatty acids in the progression of non-alcoholic fatty liver disease. Prog Lipid Res 2013. [PMID: 23178552 DOI: 10.1016/j.plipres.2012.1010.1004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The steady rise in Western obesity rates has been closely linked to significant increases in a multitude of accompanying health problems including non-alcoholic fatty liver disease (NAFLD). NAFLD severity ranges from simple steatosis to acute steatohepatitis, but the molecular mechanisms controlling progression of this disease are poorly understood. Recent literature suggests that elevated free fatty acids (FFAs), especially saturated FFAs, may play an important role in lipotoxic mechanisms, both in experimental models and in NAFLD patients. This review highlights important cellular pathways involved in hepatic lipotoxicity and how the degree of intrahepatic lipid saturation controls cell fate in response to an elevated FFA load. Relevant cellular processes that have been causally linked to lipid-induced apoptosis, known as lipoapoptosis, include endoplasmic reticulum (ER) stress, oxidative stress, mitochondrial dysfunction, and Jun N-terminal kinase (JNK) signaling. In contrast, increased triglyceride synthesis has been shown to have a protective effect against lipotoxicity, despite being one of the hallmark traits of NAFLD. Developing a more nuanced understanding of the molecular mechanisms underlying NAFLD progression will lead to more targeted and effective therapeutics for this increasingly prevalent disease, which to date has no proven pharmacologic treatment to prevent or reverse its course.
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Affiliation(s)
- Alexandra K Leamy
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235, USA
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43
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Leamy AK, Egnatchik RA, Young JD. Molecular mechanisms and the role of saturated fatty acids in the progression of non-alcoholic fatty liver disease. Prog Lipid Res 2012. [PMID: 23178552 DOI: 10.1016/j.plipres.2012.10.004] [Citation(s) in RCA: 294] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The steady rise in Western obesity rates has been closely linked to significant increases in a multitude of accompanying health problems including non-alcoholic fatty liver disease (NAFLD). NAFLD severity ranges from simple steatosis to acute steatohepatitis, but the molecular mechanisms controlling progression of this disease are poorly understood. Recent literature suggests that elevated free fatty acids (FFAs), especially saturated FFAs, may play an important role in lipotoxic mechanisms, both in experimental models and in NAFLD patients. This review highlights important cellular pathways involved in hepatic lipotoxicity and how the degree of intrahepatic lipid saturation controls cell fate in response to an elevated FFA load. Relevant cellular processes that have been causally linked to lipid-induced apoptosis, known as lipoapoptosis, include endoplasmic reticulum (ER) stress, oxidative stress, mitochondrial dysfunction, and Jun N-terminal kinase (JNK) signaling. In contrast, increased triglyceride synthesis has been shown to have a protective effect against lipotoxicity, despite being one of the hallmark traits of NAFLD. Developing a more nuanced understanding of the molecular mechanisms underlying NAFLD progression will lead to more targeted and effective therapeutics for this increasingly prevalent disease, which to date has no proven pharmacologic treatment to prevent or reverse its course.
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Affiliation(s)
- Alexandra K Leamy
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235, USA
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44
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Anticancer mechanisms and clinical application of alkylphospholipids. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:663-74. [PMID: 23137567 DOI: 10.1016/j.bbalip.2012.10.008] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 10/28/2012] [Accepted: 10/29/2012] [Indexed: 11/20/2022]
Abstract
Synthetic alkylphospholipids (ALPs), such as edelfosine, miltefosine, perifosine, erucylphosphocholine and erufosine, represent a relatively new class of structurally related antitumor agents that act on cell membranes rather than on DNA. They selectively target proliferating (tumor) cells, inducing growth arrest and apoptosis, and are potent sensitizers of conventional chemo- and radiotherapy. ALPs easily insert in the outer leaflet of the plasma membrane and cross the membrane via an ATP-dependent CDC50a-containing 'flippase' complex (in carcinoma cells), or are internalized by lipid raft-dependent endocytosis (in lymphoma/leukemic cells). ALPs resist catabolic degradation, therefore accumulate in the cell and interfere with lipid-dependent survival signaling pathways, notably PI3K-Akt and Raf-Erk1/2, and de novo phospholipid biosynthesis. At the same time, stress pathways (e.g. stress-activated protein kinase/JNK) are activated to promote apoptosis. In many preclinical and clinical studies, perifosine was the most effective ALP, mainly because it inhibits Akt activity potently and consistently, also in vivo. This property is successfully exploited clinically in highly malignant tumors, such as multiple myeloma and neuroblastoma, in which a tyrosine kinase receptor/Akt pathway is amplified. In such cases, perifosine therapy is most effective in combination with conventional anticancer regimens or with rapamycin-type mTOR inhibitors, and may overcome resistance to these agents. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.
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45
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Tanaka N, Matsubara T, Krausz KW, Patterson AD, Gonzalez FJ. Disruption of phospholipid and bile acid homeostasis in mice with nonalcoholic steatohepatitis. Hepatology 2012; 56:118-29. [PMID: 22290395 PMCID: PMC6371056 DOI: 10.1002/hep.25630] [Citation(s) in RCA: 201] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 01/20/2012] [Indexed: 02/06/2023]
Abstract
UNLABELLED Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease that can develop into cirrhosis, hepatic failure, and hepatocellular carcinoma. Although several metabolic pathways are disrupted and endogenous metabolites may change in NASH, the alterations in serum metabolites during NASH development remain unclear. To gain insight into the disease mechanism, serum metabolite changes were assessed using metabolomics with ultraperformance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry and a conventional mouse NASH model induced by a methionine- and choline-deficient (MCD) diet. Significant decreases in serum palmitoyl-, stearoyl-, and oleoyl-lysophosphatidylcholine (LPC) and marked increases in tauro-β-muricholate, taurocholate and 12-hydroxyeicosatetraenoic acid (12-HETE) were detected in mice with NASH. In agreement with these metabolite changes, hepatic mRNAs encoding enzymes and proteins involved in LPC degradation (lysophosphatidylcholine acyltransferase [Lpcat] 1-4), basolateral bile acid excretion (ATP-binding cassette subfamily C member [Abcc] 1/4/5 and organic solute transporter β), and 12-HETE synthesis (arachidonate 12-lipoxygenase) were significantly up-regulated. In contrast, the expression of solute carrier family 10 member 1 (Slc10a1) and solute carrier organic anion transporter family member (Slco) 1a1 and 1b2, responsible for transporting bile acids into hepatocytes, were markedly suppressed. Supplementation of the MCD diet with methionine revealed that the changes in serum metabolites and the related gene expression were derived from steatohepatitis, but not dietary choline deficiency or steatosis. Furthermore, tumor necrosis factor-α and transforming growth factor-β1 induced the expression of Lpcat2/4 and Abcc1/4 and down-regulated Slc10a1 and Slco1a1 in primary hepatocytes, suggesting an association between the changes in serum LPC and bile acids and proinflammatory cytokines. Finally, induction of hepatitis in ob/ob mice by D-galactosamine injection led to similar changes in serum metabolites and related gene expression. CONCLUSION Phospholipid and bile acid metabolism is disrupted in NASH, likely due to enhanced hepatic inflammatory signaling.
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Affiliation(s)
- Naoki Tanaka
- laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Tsutomu Matsubara
- laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Kristopher W. Krausz
- laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Andrew D. Patterson
- laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD;,Department of Veterinary and Biomedical Sciences and the Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA
| | - Frank J. Gonzalez
- laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
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Wang J, Fang X, Liang W. Pegylated phospholipid micelles induce endoplasmic reticulum-dependent apoptosis of cancer cells but not normal cells. ACS NANO 2012; 6:5018-5030. [PMID: 22578158 DOI: 10.1021/nn300571c] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The rapid developments in nanotechnology have brought with them a deep concern over the safety of nanomaterials. Investigating the molecular mechanisms underlying their toxicity in different cell lines will help us better understand and apply nanomaterials appropriately. Poly(ethylene glycol)-phosphoethanolamine (PEG-PE) is an FDA-approved nonionic diblock copolymer and is widely used in drug delivery systems. Here, we find that PEG-PE accumulates in the endoplasmic reticulum (ER) and induces ER stress and that cancer cells and normal cells have different cell fates as a result of this stress. In A549 cancer cells, PEG-PE damages ER functions and triggers apoptosis by activating proapoptotic UPR signaling and high expression of cell death effector CHOP and proapoptotic Bax/Bak. In addition, PEG-PE-induced ER stress also up-regulates lipid synthesis and triggers lipid droplet formation in cancer cells. By contrast, in MRC-5 and 293T cells, high expression of the UPR feedback protein GADD34 which inhibits proapoptotic UPR signaling, and antiapoptotic Bcl-2 and Bcl-xl which down-regulate Bax/Bak, protect these normal cells from PEG-PE-induced apoptosis. When gadd34, bcl-2, or bcl-xl is knocked down, apoptosis occurs in PEG-PE-treated normal cells. In summary, we demonstrate the safety of PEG-PE in normal cells and elaborate the molecular mechanism underlying its nanotoxicity in cancer cells. This study implies PEG-PE-based drug delivery system has the potential to alter the sensitivity of cancer cells to some chemotherapeutic agents by selectively activating unfolded protein response (UPR) in cancer cells, and it also provides a useful foundation for research on ER stress-induced nanotoxicity and other lipid-based nanomaterials.
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Affiliation(s)
- Jing Wang
- Protein and Peptide Pharmaceutical Laboratory, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
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47
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Synthetic phosphoethanolamine a precursor of membrane phospholipids reduce tumor growth in mice bearing melanoma B16-F10 and in vitro induce apoptosis and arrest in G2/M phase. Biomed Pharmacother 2012; 66:541-8. [PMID: 22902646 DOI: 10.1016/j.biopha.2012.04.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 04/26/2012] [Indexed: 11/21/2022] Open
Abstract
Phosphoethanolamine (Pho-s) is a compound involved in phospholipid turnover, acting as a substrate for many phospholipids of the cell membranes, especially phosphatidylcholine. We recently reported that synthetic Pho-s has potent effects on a wide variety of tumor cells. To determine if Pho-s has a potential antitumor activity, in this study we evaluated the activity of Pho-s against the B16-F10 melanoma both in vitro and in mice bearing a dorsal tumor. The treatment of B16F10 cells with Pho-s resulted in a dose-dependent inhibition of cell proliferation. At low concentrations, this activity appears to be involved in the arrest of the cell cycle at G2/M, while at high concentrations Pho-s induces apoptosis. In accordance with these results, the loss of mitochondrial potential and increased caspase-3 activity suggest that Pho-s has dual antitumor effects; i.e. it induces apoptosis at high concentrations and modulates the cell cycle at lower concentrations. In vivo, we evaluated the effect of Pho-s in mice bearing B16-F10 melanoma. The results show that Pho-s reduces the tumoral volume increasing survival rate. Furthermore, the tumor doubling time and tumor delays were substantially reduced when compared with untreated mice. Histological analyses reveal that Pho-s induces changes in cell morphology, typical characteristics of apoptosis, in addition the large areas of necrosis correlating with a reduction of tumor size. The results presented here support the hypothesis that Pho-s has antitumor effects by the induction of apoptosis as well as the inhibition of cell proliferation by arrest at G2/M. Thus, Pho-s can be regarded as a promising agent for the treatment of melanoma.
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48
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Yu X, Liu Z, Janzen J, Chafeeva I, Horte S, Chen W, Kainthan RK, Kizhakkedathu JN, Brooks DE. Polyvalent choline phosphate as a universal biomembrane adhesive. NATURE MATERIALS 2012; 11:468-476. [PMID: 22426460 DOI: 10.1038/nmat3272] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 02/07/2012] [Indexed: 05/31/2023]
Abstract
Phospholipids in the cell membranes of all eukaryotic cells contain phosphatidyl choline (PC) as the headgroup. Here we show that hyperbranched polyglycerols (HPGs) decorated with the 'PC-inverse' choline phosphate (CP) in a polyvalent fashion can electrostatically bind to a variety of cell membranes and to PC-containing liposomes, the binding strength depending on the number density of CP groups per macromolecule. We also show that HPG-CPs can cause cells to adhere with varying affinity to other cells, and that binding can be reversed by subsequent exposure to low molecular weight HPGs carrying small numbers of PCs. Moreover, PC-rich membranes adsorb and rapidly internalize fluorescent HPG-CP but not HPG-PC molecules, which suggests that HPG-CPs could be used as drug-delivery agents. CP-decorated polymers should find broad use, for instance as tissue sealants and in the self-assembly of lipid nanostructures.
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Affiliation(s)
- Xifei Yu
- Centre for Blood Research, 2350 Health Sciences Mall, University of British Columbia, Vancouver V6T 1Z3, Canada
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49
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Niebergall LJ, Vance DE. The ratio of phosphatidylcholine to phosphatidylethanolamine does not predict integrity of growing MT58 Chinese hamster ovary cells. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:324-34. [DOI: 10.1016/j.bbalip.2011.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 09/30/2011] [Accepted: 10/24/2011] [Indexed: 12/15/2022]
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50
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UPR-Mediated Membrane Biogenesis in B Cells. Biochem Res Int 2011; 2012:738471. [PMID: 22110962 PMCID: PMC3206326 DOI: 10.1155/2012/738471] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 08/25/2011] [Indexed: 02/04/2023] Open
Abstract
The unfolded protein
response (UPR) can coordinate the regulation of
gene transcription and protein translation to
balance the load of client proteins with the
protein folding and degradative capacities of
the ER. Increasing evidence also implicates the
UPR in the regulation of lipid synthesis and
membrane biogenesis. The differentiation of
B lymphocytes into antibody-secreting cells is
marked by significant expansion of the ER, the
site for antibody synthesis and assembly. In
activated B cells, the demand for membrane
protein and lipid components leads to activation
of the UPR transcriptional activator XBP1(S)
which, in turn, initiates a cascade of
biochemical events that enhance supplies of
phospholipid precursors and build machinery for
the synthesis, maturation, and transport of
secretory proteins. The alterations in lipid
metabolism that occur during this developmental
transition and the impact of membrane
phospholipid restriction on B cell secretory
characteristics are discussed in this
paper.
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