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Cao S, Jiang J, Yin H, Wang L, Lu Q. Abnormal energy metabolism in the pathogenesis of systemic lupus erythematosus. Int Immunopharmacol 2024; 134:112149. [PMID: 38692019 DOI: 10.1016/j.intimp.2024.112149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/20/2024] [Accepted: 04/21/2024] [Indexed: 05/03/2024]
Abstract
Systemic lupus erythematosus (SLE) is a severe autoimmune disease with significant socioeconomic impact worldwide. Orderly energy metabolism is essential for normal immune function, and disordered energy metabolism is increasingly recognized as an important contributor to the pathogenesis of SLE. Disorders of energy metabolism are characterized by increased reactive oxygen species, ATP deficiency, and abnormal metabolic pathways. Oxygen and mitochondria are critical for the production of ATP, and both mitochondrial dysfunction and hypoxia affect the energy production processes. In addition, several signaling pathways, including mammalian target of rapamycin (mTOR)/adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling and the hypoxia-inducible factor (HIF) pathway also play important regulatory roles in energy metabolism. Furthermore, drugs with clear clinical effects on SLE, such as sirolimus, metformin, and tacrolimus, have been proven to improve the disordered energy metabolism of immune cells, suggesting the potential of targeting energy metabolism for the treatment of SLE. Moreover, several metabolic modulators under investigation are expected to have potential therapeutic effects in SLE. This review aimed to gain insights into the role and mechanism of abnormal energy metabolism in the pathogenesis of SLE, and summarizes the progression of metabolic modulator in the treatment of SLE.
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Affiliation(s)
- Shumei Cao
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing, 210042, China; Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Jiao Jiang
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing, 210042, China
| | - Haoyuan Yin
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing, 210042, China; Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Lai Wang
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing, 210042, China; Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China.
| | - Qianjin Lu
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing, 210042, China; Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China; Hunan Key Laboratory of Medical Epigenomics, The Second Xiangya Hospital, Central South University, Changsha, 410011, China.
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2
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Verstegen NJM, Pollastro S, Unger PPA, Marsman C, Elias G, Jorritsma T, Streutker M, Bassler K, Haendler K, Rispens T, Schultze JL, ten Brinke A, Beyer M, van Ham SM. Single-cell analysis reveals dynamics of human B cell differentiation and identifies novel B and antibody-secreting cell intermediates. eLife 2023; 12:83578. [PMID: 36861964 PMCID: PMC10005767 DOI: 10.7554/elife.83578] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 02/24/2023] [Indexed: 03/03/2023] Open
Abstract
Differentiation of B cells into antibody-secreting cells (ASCs) is a key process to generate protective humoral immunity. A detailed understanding of the cues controlling ASC differentiation is important to devise strategies to modulate antibody formation. Here, we dissected differentiation trajectories of human naive B cells into ASCs using single-cell RNA sequencing. By comparing transcriptomes of B cells at different stages of differentiation from an in vitro model with ex vivo B cells and ASCs, we uncovered a novel pre-ASC population present ex vivo in lymphoid tissues. For the first time, a germinal-center-like population is identified in vitro from human naive B cells and possibly progresses into a memory B cell population through an alternative route of differentiation, thus recapitulating in vivo human GC reactions. Our work allows further detailed characterization of human B cell differentiation into ASCs or memory B cells in both healthy and diseased conditions.
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Affiliation(s)
- Niels JM Verstegen
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
- Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of AmsterdamAmsterdamNetherlands
| | - Sabrina Pollastro
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Peter-Paul A Unger
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Casper Marsman
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - George Elias
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Tineke Jorritsma
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Marij Streutker
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Kevin Bassler
- Genomics and Immunoregulation, University of BonnBonnGermany
| | - Kristian Haendler
- Genomics and Immunoregulation, University of BonnBonnGermany
- Platform for Single Cell Genomics and Epigenomics, German Center for Neurodegenerative Diseases (DZNE), University of BonnBonnGermany
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Joachim L Schultze
- Genomics and Immunoregulation, University of BonnBonnGermany
- Platform for Single Cell Genomics and Epigenomics, German Center for Neurodegenerative Diseases (DZNE), University of BonnBonnGermany
| | - Anja ten Brinke
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
| | - Marc Beyer
- Genomics and Immunoregulation, University of BonnBonnGermany
- Platform for Single Cell Genomics and Epigenomics, German Center for Neurodegenerative Diseases (DZNE), University of BonnBonnGermany
- Immunogenomics & Neurodegeneration, German Center for Neurodegenerative DiseasesBonnGermany
| | - S Marieke van Ham
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of AmsterdamAmsterdamNetherlands
- Swammerdam Institute for Life Sciences, University of AmsterdamAmsterdamNetherlands
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3
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Vivas-García Y, Efeyan A. The metabolic plasticity of B cells. Front Mol Biosci 2022; 9:991188. [PMID: 36213123 PMCID: PMC9537818 DOI: 10.3389/fmolb.2022.991188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
The humoral response requires rapid growth, biosynthetic capacity, proliferation and differentiation of B cells. These processes involve profound B-cell phenotypic transitions that are coupled to drastic changes in metabolism so as to meet the extremely different energetic requirements as B cells switch from resting to an activated, highly proliferative state and to plasma or memory cell fates. Thus, B cells execute a multi-step, energetically dynamic process of profound metabolic rewiring from low ATP production to transient and large increments of energy expenditure that depend on high uptake and consumption of glucose and fatty acids. Such metabolic plasticity is under tight transcriptional and post-transcriptional regulation. Alterations in B-cell metabolism driven by genetic mutations or by extrinsic insults impair B-cell functions and differentiation and may underlie the anomalous behavior of pathological B cells. Herein, we review molecular switches that control B-cell metabolism and fuel utilization, as well as the emerging awareness of the impact of dynamic metabolic adaptations of B cells throughout the different phases of the humoral response.
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4
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Shrestha P, Klann E. Spatiotemporally resolved protein synthesis as a molecular framework for memory consolidation. Trends Neurosci 2022; 45:297-311. [PMID: 35184897 PMCID: PMC8930706 DOI: 10.1016/j.tins.2022.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/25/2023]
Abstract
De novo protein synthesis is required for long-term memory consolidation. Dynamic regulation of protein synthesis occurs via a complex interplay of translation factors and modulators. Many components of the protein synthesis machinery have been targeted either pharmacologically or genetically to establish its requirement for memory. The combination of ligand/light-gating and genetic strategies, that is, chemogenetics and optogenetics, has begun to reveal the spatiotemporal resolution of protein synthesis in specific cell types during memory consolidation. This review summarizes current knowledge of the macroscopic and microscopic neural substrates for protein synthesis in memory consolidation. In addition, we highlight future directions for determining the localization and timing of de novo protein synthesis for memory consolidation with tools that permit unprecedented spatiotemporal precision.
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Affiliation(s)
- Prerana Shrestha
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY 10012, USA; NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
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5
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Ricci D, Gidalevitz T, Argon Y. The special unfolded protein response in plasma cells. Immunol Rev 2021; 303:35-51. [PMID: 34368957 DOI: 10.1111/imr.13012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/08/2021] [Indexed: 12/11/2022]
Abstract
The high rate of antibody production places considerable metabolic and folding stress on plasma cells (PC). Not surprisingly, they rely on the unfolded protein response (UPR), a universal signaling, and transcriptional network that monitors the health of the secretory pathway and mounts cellular responses to stress. Typically, the UPR utilizes three distinct stress sensors in the ER membrane, each regulating a subset of targets to re-establish homeostasis. PC use a specialized UPR scheme-they preemptively trigger the UPR via developmental signals and suppress two of the sensors, PERK and ATF6, relying on IRE1 alone. The specialized PC UPR program is tuned to the specific needs at every stage of development-from early biogenesis of secretory apparatus, to massive immunoglobulin expression later. Furthermore, the UPR in PC integrates with other pathways essential in a highly secretory cell-mTOR pathway that ensures efficient synthesis, autophagosomes that recycle components of the synthetic machinery, and apoptotic signaling that controls cell fate in the face of excessive folding stress. This specialized PC program is not shared with other secretory cells, for reasons yet to be defined. In this review, we give a perspective into how and why PC need such a unique UPR program.
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Affiliation(s)
- Daniela Ricci
- Department of Pathology and Lab Medicine, The Childrens' Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, PA, USA
| | - Tali Gidalevitz
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Yair Argon
- Department of Pathology and Lab Medicine, The Childrens' Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, PA, USA
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6
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Zhou Q, Zhang Y, Lu X, Wang C, Pei X, Lu Y, Cao C, Xu C, Zhang B. Stable overexpression of mutated PTEN in Chinese hamster ovary cells enhances their performance and therapeutic antibody production. Biotechnol J 2021; 16:e2000623. [PMID: 34053183 DOI: 10.1002/biot.202000623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 05/23/2021] [Accepted: 05/27/2021] [Indexed: 12/19/2022]
Abstract
Chinese hamster ovary (CHO) cells with a high viable cell density (VCD), resilience to culture stress, and the capacity to continuously express recombinant proteins are highly desirable. Phosphatase and tension homology deleted on chromosome ten (PTEN) functions as a key negative regulator of the PI3K/Akt signaling pathway, mediating cell growth and survival. Its oncogenic mutant endows cells with an enhanced proliferation rate and resistance to death. In this study, the role of oncogenic PTEN C124S or G129E on the performance of CHO-K1 and CHO-IgG cells was investigated. Our results showed that CHO-K1 cells stably expressing PTEN C124S or G129E exhibited enhanced proliferation, reduced apoptosis rate, and increased transient expression of therapeutic antibodies compared to the control cells. Moreover, the stable overexpression of PTEN C124S or G129E endowed CHO-IgG cells with higher cell viability, VCD, and antibody titers (yield increased by approximately 0.77-fold) in the fed-batch culture process and enhanced their performance in response to the addition of sodium lactate. Moreover, the engineering of mutated PTEN in CHO-IgG cells did not alter antibody quality. Collectively, our data suggest that mutated PTEN is a potential target for improving the manufacture of therapeutic antibodies.
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Affiliation(s)
- Qin Zhou
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Yujie Zhang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Xiaoxiang Lu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Chang Wang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Xinxin Pei
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Yafang Lu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Cheng Cao
- Beijing Institute of Biotechnology, Beijing, P. R. China
| | - Changzhi Xu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
| | - Buchang Zhang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P. R. China
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7
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Steinmetz TD, Schlötzer-Schrehardt U, Hearne A, Schuh W, Wittner J, Schulz SR, Winkler TH, Jäck HM, Mielenz D. TFG is required for autophagy flux and to prevent endoplasmic reticulum stress in CH12 B lymphoma cells. Autophagy 2020; 17:2238-2256. [PMID: 32910713 DOI: 10.1080/15548627.2020.1821546] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Plasma cells depend on quality control of newly synthesized antibodies in the endoplasmic reticulum (ER) via macroautophagy/autophagy and proteasomal degradation. The cytosolic adaptor protein TFG (Trk-fused gene) regulates ER-Golgi transport, the secretory pathway and proteasome activity in non-immune cells. We show here that TFG is upregulated during lipopolysaccharide- and CpG-induced differentiation of B1 and B2 B cells into plasmablasts, with the highest expression of TFG in mature plasma cells. CRISPR-CAS9-mediated gene disruption of tfg in the B lymphoma cell line CH12 revealed increased apoptosis, which was reverted by BCL2 but even more by ectopic TFG expression. Loss of TFG disrupted ER structure, leading to an expanded ER and increased expression of ER stress genes. When compared to wild-type CH12 cells, tfg KO CH12 cells were more sensitive toward ER stress induced by tunicamycin, monensin and proteasome inhibition or by expression of an ER-bound immunoglobulin (Ig) μ heavy (µH) chain. CH12 tfg KO B cells displayed more total LC3, lower LC3-II turnover and increased numbers and size of autophagosomes. Tandem-fluorescent-LC3 revealed less accumulation of GFP-LC3 in starved and chloroquine-treated CH12 tfg KO B cells. The GFP:RFP ratio of tandem-fluorescent-LC3 was higher in tunicamycin-treated CH12 tfg KO B cells, suggesting less autophagy flux during induced ER stress. Based on these data, we suggest that TFG controls autophagy flux in CH12 B cells and propose that TFG is a survival factor that alleviates ER stress through the support of autophagy flux in activated B cells and mature plasma cells.Abbreviations: Ab, antibody; Ag, antigen; ASC, antibody-secreting cells; ATG, autophagy-related; BCR, B cell receptor; COPII, coat protein complex II; CpG, non-methylated CpG oligonucleotide; ER, endoplasmic reticulum; ERAD, ER-associated degradation; FO, follicular; GFP, green fluorescent protein; HC, heavy chain; Ig, immunoglobulin; IRES, internal ribosomal entry site; LC, light chain; MZ, marginal zone; NFKB, nuclear factor of kappa light polypeptide gene enhancer in B cells; TLR, toll-like receptor; UPR, unfolded protein response.
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Affiliation(s)
- Tobit D Steinmetz
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | | | - Abigail Hearne
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Wolfgang Schuh
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Jens Wittner
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Sebastian R Schulz
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Thomas H Winkler
- Department of Biology, Chair of Genetics, Nikolaus-Fiebiger-Zentrum, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Hans-Martin Jäck
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Dirk Mielenz
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
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8
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Bilska A, Kusio-Kobiałka M, Krawczyk PS, Gewartowska O, Tarkowski B, Kobyłecki K, Nowis D, Golab J, Gruchota J, Borsuk E, Dziembowski A, Mroczek S. Immunoglobulin expression and the humoral immune response is regulated by the non-canonical poly(A) polymerase TENT5C. Nat Commun 2020; 11:2032. [PMID: 32341344 PMCID: PMC7184606 DOI: 10.1038/s41467-020-15835-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 03/28/2020] [Indexed: 02/06/2023] Open
Abstract
TENT5C is a non-canonical cytoplasmic poly(A) polymerase highly expressed by activated B cells to suppress their proliferation. Here we measure the global distribution of poly(A) tail lengths in responsive B cells using a Nanopore direct RNA-sequencing approach, showing that TENT5C polyadenylates immunoglobulin mRNAs regulating their half-life and consequently steady-state levels. TENT5C is upregulated in differentiating plasma cells by innate signaling. Compared with wild-type, Tent5c−/− mice produce fewer antibodies and have diminished T-cell-independent immune response despite having more CD138high plasma cells as a consequence of accelerated differentiation. B cells from Tent5c−/− mice also have impaired capacity of the secretory pathway, with reduced ER volume and unfolded protein response. Importantly, these functions of TENT5C are dependent on its enzymatic activity as catalytic mutation knock-in mice display the same defect as Tent5c−/−. These findings define the role of the TENT5C enzyme in the humoral immune response. Regulating polyadenylation is important for mRNA stability, which can in turn affect B cell maturation and humoral immune responses. Here the authors use Nanopore poly(A) sequencing to explore the importance of the cytoplasmic poly(A) polymerase TENT5C, particularly in the production of immunoglobulins.
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Affiliation(s)
- Aleksandra Bilska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland
| | - Monika Kusio-Kobiałka
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland.,Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland
| | - Paweł S Krawczyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland
| | - Olga Gewartowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland
| | - Bartosz Tarkowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland
| | - Kamil Kobyłecki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland
| | - Dominika Nowis
- Genomic Medicine, Medical University of Warsaw, Banacha 1a, 02-097, Warsaw, Poland.,Laboratory of Experimental Medicine, Center of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Jakub Golab
- Department of Immunology, Medical University of Warsaw, Banacha 1a, 02-097, Warsaw, Poland.,Centre of Preclinical Research, Medical University of Warsaw, Banacha 1a, 02-097, Warsaw, Poland
| | - Jakub Gruchota
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland
| | - Ewa Borsuk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland.,Department of Embryology, Institute of Zoology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Andrzej Dziembowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland. .,Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland. .,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland.
| | - Seweryn Mroczek
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland. .,Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland.
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9
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Teng X, Brown J, Choi SC, Li W, Morel L. Metabolic determinants of lupus pathogenesis. Immunol Rev 2020; 295:167-186. [PMID: 32162304 DOI: 10.1111/imr.12847] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022]
Abstract
The metabolism of healthy murine and more recently human immune cells has been investigated with an increasing amount of details. These studies have revealed the challenges presented by immune cells to respond rapidly to a wide variety of triggers by adjusting the amount, type, and utilization of the nutrients they import. A concept has emerged that cellular metabolic programs regulate the size of the immune response and the plasticity of its effector functions. This has generated a lot of enthusiasm with the prediction that cellular metabolism could be manipulated to either enhance or limit an immune response. In support of this hypothesis, studies in animal models as well as human subjects have shown that the dysregulation of the immune system in autoimmune diseases is associated with a skewing of the immunometabolic programs. These studies have been mostly conducted on autoimmune CD4+ T cells, with the metabolism of other immune cells in autoimmune settings still being understudied. Here we discuss systemic metabolism as well as cellular immunometabolism as novel tools to decipher fundamental mechanisms of autoimmunity. We review the contribution of each major metabolic pathway to autoimmune diseases, with a focus on systemic lupus erythematosus (SLE), with the relevant translational opportunities, existing or predicted from results obtained with healthy immune cells. Finally, we review how targeting metabolic programs may present novel therapeutic venues.
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Affiliation(s)
- Xiangyu Teng
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Josephine Brown
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Seung-Chul Choi
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Wei Li
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Laurence Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
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10
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Choi SC, Morel L. Immune metabolism regulation of the germinal center response. Exp Mol Med 2020; 52:348-355. [PMID: 32132626 PMCID: PMC7156389 DOI: 10.1038/s12276-020-0392-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/16/2019] [Accepted: 01/14/2020] [Indexed: 01/16/2023] Open
Abstract
The humoral immune response requires germinal centers to produce high-affinity antigen-specific antibodies that counter pathogens. Numerous studies have provided a better understanding of how metabolic pathways regulate the development, activation and functions of immune cells. Germinal centers are transient, highly dynamic microanatomic structures that develop in lymphoid organs during a T-cell-dependent humoral immune response. Analysis of germinal centers provides an opportunity to understand how metabolic programs control the differentiation and function of highly specialized germinal center B cells and follicular helper CD4+ T cells. Targeting immunometabolism during the germinal center response may afford the possibility to improve vaccine design and to develop new therapies to alleviate autoimmunity. In this review, we discuss the major metabolic pathways that are used by germinal center B and T cells, as well as the plasma cells that they produce, all of which are influenced by the microenvironment of this unique structure of the adaptive immune system. Studies of the metabolic mechanisms involved in antibody production will inform vaccine design and autoimmune disease treatments. Germinal centers (GCs) are transient sites in lymph nodes and the spleen, formed when white blood cells called T-cell lymphocytes respond to infection. GCs act as factories where another lymphocyte group, B cells, proliferates and mutates before producing infection-appropriate antibodies. GCs therefore play a critical role in adaptive immunity, but the metabolic pathways involved are unclear. Laurence Morel and Seung-Chui Choi at the University of Florida, Gainesville, USA, reviewed understanding of the metabolic pathways used by T cells, B cells and the antibodies they produce. The cells within GCs require different energy sources and metabolic pathways according to their developmental stage, to ensure optimal immune responses. The researchers call for extensive profiling of this complex metabolic system.
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Affiliation(s)
- Seung-Chul Choi
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Laurence Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA.
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11
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D'Souza L, Bhattacharya D. Plasma cells: You are what you eat. Immunol Rev 2019; 288:161-177. [PMID: 30874356 DOI: 10.1111/imr.12732] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/03/2018] [Indexed: 12/26/2022]
Abstract
Plasma cells are terminally differentiated B lymphocytes that constitutively secrete antibodies. These antibodies can provide protection against pathogens, and their quantity and quality are the best clinical correlates of vaccine efficacy. As such, plasma cell lifespan is the primary determinant of the duration of humoral immunity. Yet dysregulation of plasma cell function can cause autoimmunity or multiple myeloma. The longevity of plasma cells is primarily dictated by nutrient uptake and non-transcriptionally regulated metabolic pathways. We have previously shown a positive effect of glucose uptake and catabolism on plasma cell longevity and function. In this review, we discuss these findings with an emphasis on nutrient uptake and its effects on respiratory capacity, lifespan, endoplasmic reticulum stress, and antibody secretion in plasma cells. We further discuss how some of these pathways may be dysregulated in multiple myeloma, potentially providing new therapeutic targets. Finally, we speculate on the connection between plasma cell intrinsic metabolism and systemic changes in nutrient availability and metabolic diseases.
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Affiliation(s)
- Lucas D'Souza
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Deepta Bhattacharya
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, Arizona
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12
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Ufbp1 promotes plasma cell development and ER expansion by modulating distinct branches of UPR. Nat Commun 2019; 10:1084. [PMID: 30842412 PMCID: PMC6403283 DOI: 10.1038/s41467-019-08908-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 01/24/2019] [Indexed: 02/03/2023] Open
Abstract
The IRE1α/XBP1 branch of unfolded protein response (UPR) pathway has a critical function in endoplasmic reticulum (ER) expansion in plasma cells via unknown mechanisms; interestingly, another UPR branch, PERK, is suppressed during plasma cell development. Here we show that Ufbp1, a target and cofactor of the ufmylation pathway, promotes plasma cell development by suppressing the activation of PERK. By contrast, the IRE1α/XBP1 axis upregulates the expression of Ufbp1 and ufmylation pathway genes in plasma cells, while Ufbp1 deficiency impairs ER expansion in plasma cells and retards immunoglobulin production. Structure and function analysis suggests that lysine 267 of Ufbp1, the main lysine in Ufbp1 that undergoes ufmylation, is dispensable for the development of plasmablasts, but is required for immunoglobulin production and stimulation of ER expansion in IRE1α-deficient plasmablasts. Thus, Ufbp1 distinctly regulates different branches of UPR pathway to promote plasma cell development and function. IRE1 and PERK, both important mediators of the unfold protein response pathway, are differentially regulated during plasma cell differentiation. Here the authors show that an ufmylation target, Ufbp1, suppresses PERK to stimulate plasma cell development and is induced by the IRE1/XBP1 pathway to promote ER expansion .
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13
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Wei Y, Meng M, Tian Z, Xie F, Yin Q, Dai C, Wang J, Zhang Q, Liu Y, Liu C, Yan F, Jiang F, Guo X. Pharmacological preconditioning with the cellular stress inducer thapsigargin protects against experimental sepsis. Pharmacol Res 2018; 141:114-122. [PMID: 30579975 DOI: 10.1016/j.phrs.2018.12.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/12/2018] [Accepted: 12/19/2018] [Indexed: 02/08/2023]
Abstract
Previous studies have shown that pretreatment with thapsigargin (TG), a cellular stress inducer, produced potent protective actions against various pathologic injuries. So far there is no information on the effects of TG on the development of bacterial sepsis. Using lipopolysaccharides- and cecal ligation/puncture-induced sepsis models in mice, we demonstrated that preconditioning with a single bolus administration of TG conferred significant improvements in survival. The beneficial effects of TG were not mediated by ER stress induction or changes in Toll-like receptor 4 signaling. In vivo and in cultured macrophages, we identified that TG reduced the protein production of pro-inflammatory cytokines, but exhibited no significant effects on steady state levels of their transcriptions. Direct measurement on the fraction of polysome-bound mRNAs revealed that TG reduced the translational efficiency of pro-inflammatory cytokines in macrophages. Moreover, we provided evidence suggesting that repression of the mTOR (the mammalian target of rapamycin) signaling pathway, but not activation of the PERK (protein kinase R-like endoplasmic reticulum kinase)-eIF2α (eukaryotic initiation factor 2α) pathway, might be involved in mediating the TG effects on cytokine production. In summary, our results support that pharmacological preconditioning with TG may represent a novel strategy to prevent sepsis-induced mortality and organ injuries.
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Affiliation(s)
- Yaping Wei
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China
| | - Mei Meng
- Department of Critical Care Medicine, Shandong Provincial Hospital Affiliated, Shandong University, Jinan, Shandong Province, China
| | - Zhenyu Tian
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China
| | - Fubo Xie
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Qihui Yin
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China
| | - Chaochao Dai
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China
| | - Jingjing Wang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China
| | - Qunye Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China
| | - Yu Liu
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China
| | - Chang Liu
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China
| | - Feng Yan
- Department of Emergency, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Fan Jiang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China; The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China.
| | - Xiaosun Guo
- Department of Physiology and Pathophysiology, School of Basic Medicine, Shandong University, Jinan, Shandong Province, China.
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Carew NT, Nelson AM, Liang Z, Smith SM, Milcarek C. Linking Endoplasmic Reticular Stress and Alternative Splicing. Int J Mol Sci 2018; 19:ijms19123919. [PMID: 30544499 PMCID: PMC6321306 DOI: 10.3390/ijms19123919] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 12/16/2022] Open
Abstract
RNA splicing patterns in antibody-secreting cells are shaped by endoplasmic reticulum stress, ELL2 (eleven-nineteen lysine-rich leukemia gene 2) induction, and changes in the levels of snRNAs. Endoplasmic reticulum stress induces the unfolded protein response comprising a highly conserved set of genes crucial for cell survival; among these is Ire1, whose auto-phosphorylation drives it to acquire a regulated mRNA decay activity. The mRNA-modifying function of phosphorylated Ire1 non-canonically splices Xbp1 mRNA and yet degrades other cellular mRNAs with related motifs. Naïve splenic B cells will activate Ire1 phosphorylation early on after lipopolysaccharide (LPS) stimulation, within 18 h; large-scale changes in mRNA content and splicing patterns result. Inhibition of the mRNA-degradation function of Ire1 is correlated with further differences in the splicing patterns and a reduction in the mRNA factors for snRNA transcription. Some of the >4000 splicing changes seen at 18 h after LPS stimulation persist into the late stages of antibody secretion, up to 72 h. Meanwhile some early splicing changes are supplanted by new splicing changes introduced by the up-regulation of ELL2, a transcription elongation factor. ELL2 is necessary for immunoglobulin secretion and does this by changing mRNA processing patterns of immunoglobulin heavy chain and >5000 other genes.
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Affiliation(s)
- Nolan T Carew
- School of Medicine, Department of Immunology, University of Pittsburgh, E1059 Biomedical Science Tower, Pittsburgh, PA 15261, USA.
| | - Ashley M Nelson
- School of Medicine, Department of Immunology, University of Pittsburgh, E1059 Biomedical Science Tower, Pittsburgh, PA 15261, USA.
| | - Zhitao Liang
- School of Medicine, Department of Immunology, University of Pittsburgh, E1059 Biomedical Science Tower, Pittsburgh, PA 15261, USA.
| | - Sage M Smith
- School of Medicine, Department of Immunology, University of Pittsburgh, E1059 Biomedical Science Tower, Pittsburgh, PA 15261, USA.
| | - Christine Milcarek
- School of Medicine, Department of Immunology, University of Pittsburgh, E1059 Biomedical Science Tower, Pittsburgh, PA 15261, USA.
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15
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Purnell MC, Butawan MBA, Bingol K, Tolley EA, Whitt MA. Modulation of endoplasmic reticulum stress and the unfolded protein response in cancerous and noncancerous cells. SAGE Open Med 2018; 6:2050312118783412. [PMID: 29977552 PMCID: PMC6024343 DOI: 10.1177/2050312118783412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 05/25/2018] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES The bio-field array is a device that generates a dielectrophoretic electromagnetic field when placed in a hypotonic saline solution and a direct current of approximately 3 A is applied. It is known that cell physiology is guided by bioelectrical properties, and there is a significant growth inhibition in cancerous (MDA-MB-231) cells that are grown in media that has been reconstituted with the saline that has been exposed to the bio-field array direct current dielectrophoretic electromagnetic field, alternatively there is no growth inhibition noted in noncancerous cells (MCF-10A) when grown in the bio-field array direct current dielectrophoretic electromagnetic field treated versus control media. METHODS To examine the basis for selective growth inhibition in human breast carcinoma, we employed cell death assays, cell cycle assays, microarray analysis and reverse transcription-quantitative polymerase chain reaction. RESULTS We found a large transcriptional reprogramming in the cell lines and of the genes affected, those involved in endoplasmic reticulum stress and the unfolded protein response pathways showed some of the most dramatic changes. Cancerous cells grown in media that has been reconstituted with a hypotonic saline solution that has been exposed to the bio-field array direct current dielectrophoretic electromagnetic field show a significant and strong upregulation of the apoptotic arms of the unfolded protein response while the noncancerous cells show a decrease in endoplasmic reticulum stress via microarray analyses and reverse transcription-quantitative polymerase chain reaction. CONCLUSION The bio-field array shows potential to initiate apoptosis in cancerous cells while relieving cell stress in noncancerous cells in vitro. These studies lay a foundation for nurses to conduct future in vivo models for the possible development of future adjunct treatments in chronic disease.
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Affiliation(s)
- Marcy C Purnell
- Department of Microbiology, Immunology
and Biochemistry, College of Medicine, The University of Tennessee Health Science
Center, Memphis, TN, USA
- The Loewenberg College of Nursing, The
University of Memphis, Memphis, TN, USA
| | | | - Kemal Bingol
- Department of Microbiology, Immunology
and Biochemistry, College of Medicine, The University of Tennessee Health Science
Center, Memphis, TN, USA
| | - Elizabeth A Tolley
- Department of Preventive Medicine, The
University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michael A Whitt
- Department of Microbiology, Immunology
and Biochemistry, College of Medicine, The University of Tennessee Health Science
Center, Memphis, TN, USA
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16
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Wortel IMN, van der Meer LT, Kilberg MS, van Leeuwen FN. Surviving Stress: Modulation of ATF4-Mediated Stress Responses in Normal and Malignant Cells. Trends Endocrinol Metab 2017; 28:794-806. [PMID: 28797581 PMCID: PMC5951684 DOI: 10.1016/j.tem.2017.07.003] [Citation(s) in RCA: 331] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/06/2017] [Accepted: 07/10/2017] [Indexed: 01/14/2023]
Abstract
Activating transcription factor 4 (ATF4) is a stress-induced transcription factor that is frequently upregulated in cancer cells. ATF4 controls the expression of a wide range of adaptive genes that allow cells to endure periods of stress, such as hypoxia or amino acid limitation. However, under persistent stress conditions, ATF4 promotes the induction of apoptosis. Recent advances point to a role for post-translational modifications (PTMs) and epigenetic mechanisms in balancing these pro- and anti-survival effects of ATF4. We review here how PTMs and epigenetic modifiers associated with ATF4 may be exploited by cancer cells to cope with cellular stress conditions that are intrinsically associated with tumor growth. Identification of mechanisms that modulate ATF4-mediated transcription and its effects on cellular metabolism may uncover new targets for cancer treatment.
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Affiliation(s)
- Inge M N Wortel
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud university medical center, Nijmegen, The Netherlands; Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Laurens T van der Meer
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud university medical center, Nijmegen, The Netherlands
| | - Michael S Kilberg
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL 32610-0245, USA.
| | - Frank N van Leeuwen
- Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Science, Radboud university medical center, Nijmegen, The Netherlands.
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17
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Kassambara A, Jourdan M, Bruyer A, Robert N, Pantesco V, Elemento O, Klein B, Moreaux J. Global miRNA expression analysis identifies novel key regulators of plasma cell differentiation and malignant plasma cell. Nucleic Acids Res 2017; 45:5639-5652. [PMID: 28459970 PMCID: PMC5449613 DOI: 10.1093/nar/gkx327] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 04/14/2017] [Indexed: 02/01/2023] Open
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that attenuate expression of their mRNA targets. Here, we developed a new method and an R package, to easily infer candidate miRNA–mRNA target interactions that could be functional during a given biological process. Using this method, we described, for the first time, a comprehensive integrated analysis of miRNAs and mRNAs during human normal plasma cell differentiation (PCD). Our results reveal 63 miRNAs with significant temporal changes in their expression during normal PCD. We derived a high-confidence network of 295 target relationships comprising 47 miRNAs and 141 targets. These relationships include new examples of miRNAs that appear to coordinately regulate multiple members of critical pathways associated with PCD. Consistent with this, we have experimentally validated a role for the miRNA-30b/c/d-mediated regulation of key PCD factors (IRF4, PRDM1, ELL2 and ARID3A). Furthermore, we found that 24 PCD stage-specific miRNAs are aberrantly overexpressed in multiple myeloma (MM) tumor plasma cells compared to their normal counterpart, suggesting that MM cells frequently acquired expression changes in miRNAs already undergoing dynamic expression modulation during normal PCD. Altogether, our analysis identifies candidate novel key miRNAs regulating networks of significance for normal PCD and malignant plasma cell biology.
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Affiliation(s)
- Alboukadel Kassambara
- Department of Biological Hematology, CHRU Montpellier, 34000 Montpellier, France.,Institute of Human Genetics, CNRS-UPR1142, 34000 Montpellier, France
| | - Michel Jourdan
- Institute of Human Genetics, CNRS-UPR1142, 34000 Montpellier, France
| | - Angélique Bruyer
- Department of Biological Hematology, CHRU Montpellier, 34000 Montpellier, France.,Institute of Human Genetics, CNRS-UPR1142, 34000 Montpellier, France
| | - Nicolas Robert
- Department of Biological Hematology, CHRU Montpellier, 34000 Montpellier, France
| | | | - Olivier Elemento
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Bernard Klein
- Department of Biological Hematology, CHRU Montpellier, 34000 Montpellier, France.,Institute of Human Genetics, CNRS-UPR1142, 34000 Montpellier, France.,University of Montpellier 1, UFR de Médecine, 34000 Montpellier, France
| | - Jérôme Moreaux
- Department of Biological Hematology, CHRU Montpellier, 34000 Montpellier, France.,Institute of Human Genetics, CNRS-UPR1142, 34000 Montpellier, France.,University of Montpellier 1, UFR de Médecine, 34000 Montpellier, France
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18
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Lam WY, Bhattacharya D. Metabolic Links between Plasma Cell Survival, Secretion, and Stress. Trends Immunol 2017; 39:19-27. [PMID: 28919256 DOI: 10.1016/j.it.2017.08.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 01/12/2023]
Abstract
Humoral immunity is generated and maintained by antigen-specific antibodies that counter infectious pathogens. Plasma cells are the major producers of antibodies during and after infections, and each plasma cell produces some thousands of antibody molecules per second. This magnitude of secretion requires enormous quantities of amino acids and glycosylation sugars to properly build and fold antibodies, biosynthetic substrates to fuel endoplasmic reticulum (ER) biogenesis, and additional carbon sources to generate energy. Many of these processes are likely to be linked, thereby affording possibilities to improve vaccine design and to develop new therapies for autoimmunity. We review here aspects of plasma cell biology with an emphasis on recent studies and the relationships between intermediary metabolism, antibody production, and lifespan.
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Affiliation(s)
- Wing Y Lam
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Deepta Bhattacharya
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Current address: Department of Immunobiology, University of Arizona College of Medicine, Tucson, AZ 85724, USA.
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19
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The Unfolded Protein Response in the Immune Cell Development: Putting the Caretaker in the Driving Seat. Curr Top Microbiol Immunol 2017; 414:45-72. [PMID: 28702709 DOI: 10.1007/82_2017_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The endoplasmic reticulum (ER) is the primary site for the folding of proteins destined for the membranous compartment and the extracellular space. This elaborate function is coordinated by the unfolded protein response (UPR), a stress-activated cellular program that governs proteostasis. In multicellular organisms, cells have adopted specialized functions, which required functional adaptations of the ER and its UPR. Recently, it has become clear that in immune cells, the UPR has acquired functions that stretch far beyond its original scope. In this review, we will discuss the role of the UPR in the immune system and highlight the plasticity of this signaling cascade throughout immune cell development .
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mTORC1 signalling and eIF4E/4E-BP1 translation initiation factor stoichiometry influence recombinant protein productivity from GS-CHOK1 cells. Biochem J 2016; 473:4651-4664. [PMID: 27760840 PMCID: PMC5147049 DOI: 10.1042/bcj20160845] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/17/2016] [Accepted: 10/19/2016] [Indexed: 12/14/2022]
Abstract
Many protein-based biotherapeutics are produced in cultured Chinese hamster ovary (CHO) cell lines. Recent reports have demonstrated that translation of recombinant mRNAs and global control of the translation machinery via mammalian target of rapamycin (mTOR) signalling are important determinants of the amount and quality of recombinant protein such cells can produce. mTOR complex 1 (mTORC1) is a master regulator of cell growth/division, ribosome biogenesis and protein synthesis, but the relationship between mTORC1 signalling, cell growth and proliferation and recombinant protein yields from mammalian cells, and whether this master regulating signalling pathway can be manipulated to enhance cell biomass and recombinant protein production (rPP) are not well explored. We have investigated mTORC1 signalling and activity throughout batch culture of a panel of sister recombinant glutamine synthetase-CHO cell lines expressing different amounts of a model monoclonal IgG4, to evaluate the links between mTORC1 signalling and cell proliferation, autophagy, recombinant protein expression, global protein synthesis and mRNA translation initiation. We find that the expression of the mTORC1 substrate 4E-binding protein 1 (4E-BP1) fluctuates throughout the course of cell culture and, as expected, that the 4E-BP1 phosphorylation profiles change across the culture. Importantly, we find that the eIF4E/4E-BP1 stoichiometry positively correlates with cell productivity. Furthermore, eIF4E amounts appear to be co-regulated with 4E-BP1 amounts. This may reflect a sensing of either change at the mRNA level as opposed to the protein level or the fact that the phosphorylation status, as well as the amount of 4E-BP1 present, is important in the co-regulation of eIF4E and 4E-BP1.
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21
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Jones DD, Gaudette BT, Wilmore JR, Chernova I, Bortnick A, Weiss BM, Allman D. mTOR has distinct functions in generating versus sustaining humoral immunity. J Clin Invest 2016; 126:4250-4261. [PMID: 27760048 DOI: 10.1172/jci86504] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 09/08/2016] [Indexed: 12/11/2022] Open
Abstract
Little is known about the role of mTOR signaling in plasma cell differentiation and function. Furthermore, for reasons not understood, mTOR inhibition reverses antibody-associated disease in a murine model of systemic lupus erythematosus. Here, we have demonstrated that induced B lineage-specific deletion of the gene encoding RAPTOR, an essential signaling adaptor for rapamycin-sensitive mTOR complex 1 (mTORC1), abrogated the generation of antibody-secreting plasma cells in mice. Acute treatment with rapamycin recapitulated the effects of RAPTOR deficiency, and both strategies led to the ablation of newly formed plasma cells in the spleen and bone marrow while also obliterating preexisting germinal centers. Surprisingly, although perturbing mTOR activity caused a profound decline in serum antibodies that were specific for exogenous antigen or DNA, frequencies of long-lived bone marrow plasma cells were unaffected. Instead, mTORC1 inhibition led to decreased expression of immunoglobulin-binding protein (BiP) and other factors needed for robust protein synthesis. Consequently, blockade of antibody synthesis was rapidly reversed after termination of rapamycin treatment. We conclude that mTOR signaling plays critical but diverse roles in early and late phases of antibody responses and plasma cell differentiation.
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22
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Aronov M, Tirosh B. Metabolic Control of Plasma Cell Differentiation- What We Know and What We Don't Know. J Clin Immunol 2016; 36 Suppl 1:12-7. [PMID: 26910101 DOI: 10.1007/s10875-016-0246-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 02/16/2016] [Indexed: 12/21/2022]
Abstract
Antibody secretion is executed by plasma cells that are generated in the periphery and migrate to the bone marrow to establish a long lived pool. The terminal differentiation of B lymphocytes into plasma cells is executed by a network of transcription factors that cross-regulate each other in order to irreversibly promote this transition. While major progress has been made in the understanding the transcriptional activity of the underlying master regulators, much less is known on the metabolic regulation of plasma cell differentiation that is required to support antibody synthesis, folding and secretion at high levels and allow their long-lasting survival. In this review we will address the known cross talks between the transcription and metabolic control of plasma cells and elaborate on the gaps of knowledge in the field.
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Affiliation(s)
- Michael Aronov
- Institute for Drug Research, The School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Boaz Tirosh
- Institute for Drug Research, The School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
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23
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Ishizawa J, Kojima K, Chachad D, Ruvolo P, Ruvolo V, Jacamo RO, Borthakur G, Mu H, Zeng Z, Tabe Y, Allen JE, Wang Z, Ma W, Lee HC, Orlowski R, Sarbassov DD, Lorenzi PL, Huang X, Neelapu SS, McDonnell T, Miranda RN, Wang M, Kantarjian H, Konopleva M, Davis RE, Andreeff M. ATF4 induction through an atypical integrated stress response to ONC201 triggers p53-independent apoptosis in hematological malignancies. Sci Signal 2016; 9:ra17. [PMID: 26884599 DOI: 10.1126/scisignal.aac4380] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The clinical challenge posed by p53 abnormalities in hematological malignancies requires therapeutic strategies other than standard genotoxic chemotherapies. ONC201 is a first-in-class small molecule that activates p53-independent apoptosis, has a benign safety profile, and is in early clinical trials. We found that ONC201 caused p53-independent apoptosis and cell cycle arrest in cell lines and in mantle cell lymphoma (MCL) and acute myeloid leukemia (AML) samples from patients; these included samples from patients with genetic abnormalities associated with poor prognosis or cells that had developed resistance to the nongenotoxic agents ibrutinib and bortezomib. Moreover, ONC201 caused apoptosis in stem and progenitor AML cells and abrogated the engraftment of leukemic stem cells in mice while sparing normal bone marrow cells. ONC201 caused changes in gene expression similar to those caused by the unfolded protein response (UPR) and integrated stress responses (ISRs), which increase the translation of the transcription factor ATF4 through an increase in the phosphorylation of the translation initiation factor eIF2α. However, unlike the UPR and ISR, the increase in ATF4 abundance in ONC201-treated hematopoietic cells promoted apoptosis and did not depend on increased phosphorylation of eIF2α. ONC201 also inhibited mammalian target of rapamycin complex 1 (mTORC1) signaling, likely through ATF4-mediated induction of the mTORC1 inhibitor DDIT4. Overexpression of BCL-2 protected against ONC201-induced apoptosis, and the combination of ONC201 and the BCL-2 antagonist ABT-199 synergistically increased apoptosis. Thus, our results suggest that by inducing an atypical ISR and p53-independent apoptosis, ONC201 has clinical potential in hematological malignancies.
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Affiliation(s)
- Jo Ishizawa
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Kensuke Kojima
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. Division of Hematology, Respiratory Medicine and Oncology, Department of Medicine, Saga University, Saga 840-8502, Japan
| | - Dhruv Chachad
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Peter Ruvolo
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Vivian Ruvolo
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Rodrigo O Jacamo
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Gautam Borthakur
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hong Mu
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Zhihong Zeng
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yoko Tabe
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. Department of Clinical Laboratory Medicine, Juntendo University School of Medicine, Tokyo 113-8431, Japan
| | | | - Zhiqiang Wang
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Wencai Ma
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hans C Lee
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Robert Orlowski
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Dos D Sarbassov
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Philip L Lorenzi
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xuelin Huang
- Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sattva S Neelapu
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Timothy McDonnell
- Department of Hematopathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Roberto N Miranda
- Department of Hematopathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michael Wang
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hagop Kantarjian
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Marina Konopleva
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - R Eric Davis
- Department of Lymphoma/Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Michael Andreeff
- Section of Molecular Hematology and Therapy, Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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Blimp-1 controls plasma cell function through the regulation of immunoglobulin secretion and the unfolded protein response. Nat Immunol 2016; 17:323-30. [PMID: 26779600 PMCID: PMC4757736 DOI: 10.1038/ni.3348] [Citation(s) in RCA: 238] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 11/02/2015] [Indexed: 12/17/2022]
Abstract
Plasma cell differentiation requires silencing of B cell transcription, while establishing antibody-secretory function and long-term survival. The transcription factors Blimp-1 and IRF4 are essential for plasma cell generation, however their function in mature plasma cells has remained elusive. We have found that while IRF4 was essential for plasma cell survival, Blimp-1 was dispensable. Blimp-1-deficient plasma cells retained their transcriptional identity, but lost the ability to secrete antibody. Blimp-1 regulated many components of the unfolded protein response (UPR), including XBP-1 and ATF6. The overlap of Blimp-1 and XBP-1 function was restricted to the UPR, with Blimp-1 uniquely regulating mTOR activity and plasma cell size. Thus, Blimp-1 is required for the unique physiological capacity of plasma cells that enables the secretion of protective antibody.
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Smith SM, Carew NT, Milcarek C. RNA polymerases in plasma cells trav-ELL2 the beat of a different drum. World J Immunol 2015; 5:99-112. [DOI: 10.5411/wji.v5.i3.99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/19/2015] [Accepted: 11/17/2015] [Indexed: 02/05/2023] Open
Abstract
There is a major transformation in gene expression between mature B cells (including follicular, marginal zone, and germinal center cells) and antibody secreting cells (ASCs), i.e., ASCs, (including plasma blasts, splenic plasma cells, and long-lived bone marrow plasma cells). This significant change-over occurs to accommodate the massive amount of secretory-specific immunoglobulin that ASCs make and the export processes itself. It is well known that there is an up-regulation of a small number of ASC-specific transcription factors Prdm1 (B-lymphocyte-induced maturation protein 1), interferon regulatory factor 4, and Xbp1, and the reciprocal down-regulation of Pax5, Bcl6 and Bach2, which maintain the B cell program. Less well appreciated are the major alterations in transcription elongation and RNA processing occurring between B cells and ASCs. The three ELL family members ELL1, 2 and 3 have different protein sequences and potentially distinct cellular roles in transcription elongation. ELL1 is involved in DNA repair and small RNAs while ELL3 was previously described as either testis or stem-cell specific. After B cell stimulation to ASCs, ELL3 levels fall precipitously while ELL1 falls off slightly. ELL2 is induced at least 10-fold in ASCs relative to B cells. All of these changes cause the RNA Polymerase II in ASCs to acquire different properties, leading to differences in RNA processing and histone modifications.
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26
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Zhang X, Kuramitsu Y, Ma A, Zhang H, Nakamura K. Endoplasmic reticulium protein profiling of heat-stressed Jurkat cells by one dimensional electrophoresis and liquid chromatography tandem mass spectrometry. Cytotechnology 2015; 68:1103-13. [PMID: 25976506 DOI: 10.1007/s10616-015-9867-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 03/23/2015] [Indexed: 11/25/2022] Open
Abstract
Proteomic study on membrane-integrated proteins in endoplasmic reticulum (ER) fractions was performed. In this study, we examined the effects of heat stress on Jurkat cells. The ER fractions were highly purified by differential centrifugation with sodium carbonate washing and acetone methanol precipitations. The ER membrane proteins were separated by one dimensional electrophoresis (1-DE), and some of the protein bands changed their abundance by heat stress, 12 of the 14 bands containing 40 and 60 ribosomal proteins whose expression level were decreased, on the contrary, 2 of the 14 bands containing ubiquitin and eukaryotic translation initiation factor 3 were increased. Heat treatment of human Jurkat cells led to an increase in the phosphorylation of PERK and eIF2α within 30 min of exposure. This was followed by an increase in the expression of the GRP78. Protein ubiquitination and subsequent degradation by the proteasome are important mechanisms regulating cell cycle, growth and differentiation, the result showed that heat stress enhanced ubiquitination modification of the microsomal proteins. The data of this study strongly suggest that heat treatment led to a significant reduction in protein expression and activated UPR, concomitant with protein hyperubiqutination in ER.
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Affiliation(s)
- Xiulian Zhang
- The Institute of Human Nutrition, Medical College of Qingdao University, Dengzhou Road 38, Qingdao, 266021, People's Republic of China.
- Qingdao Center for Disease Control and Prevention, Qingdao, 266032, People's Republic of China.
| | - Yasuhiro Kuramitsu
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan
| | - Aiguo Ma
- The Institute of Human Nutrition, Medical College of Qingdao University, Dengzhou Road 38, Qingdao, 266021, People's Republic of China
| | - Hui Zhang
- Zaozhuang University Hospital, Beian Road 1, Zaozhuang, 277160, People's Republic of China
| | - Kazuyuki Nakamura
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan
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Drori A, Messerle M, Brune W, Tirosh B. Lack of XBP-1 impedes murine cytomegalovirus gene expression. PLoS One 2014; 9:e110942. [PMID: 25333725 PMCID: PMC4205010 DOI: 10.1371/journal.pone.0110942] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 09/26/2014] [Indexed: 11/17/2022] Open
Abstract
The unfolded protein response (UPR) is an endoplasmic reticulum (ER)-to-nucleus signaling cascade induced in response to ER stress. The UPR aims at restoring homeostasis, but can also induce apoptosis if stress persists. Infection by human and murine cytomegaloviruses (CMVs) provokes ER stress and induces the UPR. However, both CMVs manipulate the UPR to promote its prosurvival activity and delay apoptosis. The underlying mechanisms remain largely unknown. Recently, we demonstrated that MCMV and HCMV encode a late protein to target IRE1 for degradation. However, the importance of its downstream effector, X Box binding protein 1 (XBP-1), has not been directly studied. Here we show that deletion of XBP-1 prior to or early after infection confers a transient delay in viral propagation in fibroblasts that can be overcome by increasing the viral dose. A similar phenotype was demonstrated in peritoneal macrophages. In vivo, acute infection by MCMV is reduced in the absence of XBP-1. Our data indicate that removal of XBP-1 confers a kinetic delay in early stages of MCMV infection and suggest that the late targeting of IRE1 is aimed at inhibiting activities other than the splicing of XBP-1 mRNA.
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Affiliation(s)
- Adi Drori
- Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Martin Messerle
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Wolfram Brune
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Boaz Tirosh
- Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
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mTOR activation promotes plasma cell differentiation and bypasses XBP-1 for immunoglobulin secretion. Mol Cell Biol 2014; 35:153-66. [PMID: 25332234 DOI: 10.1128/mcb.01187-14] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Plasma cells (PCs) are responsible for the secretion of antibodies. The development of fully functional PCs relies on the activation of the inositol-requiring enzyme 1/X-box binding protein 1 (IRE1/XBP-1) arm of the unfolded protein response (UPR). XBP-1-deficient PCs secrete antibodies poorly and exhibit distensions of the endoplasmic reticulum (ER). The kinase mammalian target of rapamycin (mTOR) promotes anabolic activities and is negatively regulated by the tuberous sclerosis complex (TSC). Deletion of TSC1 renders mTOR hyperactive. To explore the relationship between mTOR and the UPR in PC development and function, mice with conditional deletions of XBP-1 and/or TSC1 in their B cell lineage were generated. Deletion of TSC1 enhanced Ig synthesis and promoted differentiation into PCs independently of XBP-1, as evidenced by comparison of TSC1/XBP-1 double-knockout (DKO) PCs to XBP-1 knockout (KO) PCs. The typical morphological abnormalities of the ER in XBP-1 KO PCs were alleviated in the DKO PCs. Expression profiling identified the glycoprotein Ly6C as an mTOR target. Ly6C expression contributed to the enhanced Ig secretion from DKO PCs. Our data reveal a functional overlap between mTOR and the UPR in promoting PC development. In addition to the classical mTOR role in promoting protein synthesis, the mechanism entails transcription regulation of accessory molecules, such as Ly6C.
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29
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25-Hydroxycholesterol acts as an amplifier of inflammatory signaling. Proc Natl Acad Sci U S A 2014; 111:10666-71. [PMID: 24994901 DOI: 10.1073/pnas.1404271111] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cross-talk between sterol regulatory pathways and inflammatory pathways has been demonstrated to significantly impact the development of both atherosclerosis and infectious disease. The oxysterol 25-hydroxycholesterol (25HC) plays multiple roles in lipid biosynthesis and immunity. We recently used a systems biology approach to identify 25HC as an innate immune mediator that had a predicted role in atherosclerosis and we demonstrated a role for 25HC in foam cell formation. Here, we show that this mediator also has several complex roles in the antiviral response. The host response to viruses involves gene regulatory circuits with multiple feedback loops and we show here that 25HC acts as an amplifier of inflammatory signaling in macrophages. We determined that 25HC amplifies inflammatory signaling, at least in part, by mediating the recruitment of the AP-1 components FBJ osteosarcoma oncogene (FOS) and jun proto-oncogene (JUN) to the promoters of a subset of Toll-like receptor-responsive genes. Consistent with previous reports, we found that 25HC inhibits in vitro infection of airway epithelial cells by influenza. Surprisingly, we found that deletion of Ch25h, the gene encoding the enzyme responsible for 25HC production, is protective in a mouse model of influenza infection as a result of decreased inflammatory-induced pathology. Thus, our study demonstrates, for the first time to our knowledge, that in addition to its direct antiviral role, 25HC also regulates transcriptional responses and acts as an amplifier of inflammation via AP-1 and that the resulting alteration in inflammatory response leads to increased tissue damage in mice following infection with influenza.
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30
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Clarke AJ, Ellinghaus U, Cortini A, Stranks A, Simon AK, Botto M, Vyse TJ. Autophagy is activated in systemic lupus erythematosus and required for plasmablast development. Ann Rheum Dis 2014; 74:912-20. [PMID: 24419333 PMCID: PMC4152192 DOI: 10.1136/annrheumdis-2013-204343] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 12/15/2013] [Indexed: 12/19/2022]
Abstract
Background Autophagy has emerged as a critical homeostatic mechanism in T lymphocytes, influencing proliferation and differentiation. Autophagy in B cells has been less studied, but genetic deficiency causes impairment of early and late developmental stages Objectives To explore the role of autophagy in the pathogenesis of human and murine lupus, a disease in which B cells are critical effectors of pathology. Methods Autophagy was assessed using multiple techniques in NZB/W and control mice, and in patients with systemic lupus erythematosus (SLE) compared to healthy controls. We evaluated the phenotype of the B cell compartment in Vav-Atg7−/− mice in vivo, and examined human and murine plasmablast formation following inhibition of autophagy. Results We found activation of autophagy in early developmental and transitional stages of B cell development in a lupus mouse model even before disease onset, and which progressively increased with age. In human disease, again autophagy was activated compared with healthy controls, principally in naïve B cells. B cells isolated from Vav-Atg7F/F mice failed to effectively differentiate into plasma cells following stimulation in vitro. Similarly, human B cells stimulated in the presence of autophagy inhibition did not differentiate into plasmablasts. Conclusions Our data suggest activation of autophagy is a mechanism for survival of autoreactive B cells, and also demonstrate that it is required for plasmablast differentiation, processes that induce significant cellular stress. The implication of autophagy in two major pathogenic pathways in SLE suggests the potential to use inhibition of autophagy as a novel treatment target in this frequently severe autoimmune disease.
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Affiliation(s)
- Alexander J Clarke
- Medical and Molecular Genetics and Division of Immunology, Infection, and Inflammatory Disease, King's College London, London, UK
| | - Ursula Ellinghaus
- Medical and Molecular Genetics and Division of Immunology, Infection, and Inflammatory Disease, King's College London, London, UK
| | - Andrea Cortini
- Medical and Molecular Genetics and Division of Immunology, Infection, and Inflammatory Disease, King's College London, London, UK
| | - Amanda Stranks
- Nuffield Department of Clinical Medicine and Translational Immunology Laboratory, NIHR BRC, University of Oxford, Oxford, UK
| | - Anna Katharina Simon
- Nuffield Department of Clinical Medicine and Translational Immunology Laboratory, NIHR BRC, University of Oxford, Oxford, UK
| | - Marina Botto
- Department of Medicine, Centre for Complement and Inflammation Research, Imperial College London, London, UK
| | - Timothy J Vyse
- Medical and Molecular Genetics and Division of Immunology, Infection, and Inflammatory Disease, King's College London, London, UK
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François A, Terro F, Janet T, Rioux Bilan A, Paccalin M, Page G. Involvement of interleukin-1β in the autophagic process of microglia: relevance to Alzheimer's disease. J Neuroinflammation 2013; 10:151. [PMID: 24330807 PMCID: PMC3878742 DOI: 10.1186/1742-2094-10-151] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/24/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Autophagy is a major pathway of protein and organelle degradation in the lysosome. Autophagy exists at basal constitutive level and can be induced as a defense mechanism under stress conditions. Molecular relationships between autophagy and inflammation at the periphery were recently evidenced, highlighting a role of autophagy in the regulation of inflammation. Impairment of autophagy (with accumulation of autophagic vacuoles) and substantial inflammation are found in neurodegenerative diseases such as Alzheimer's Disease (AD). However, the links between autophagy and inflammation in AD remain to be determined. METHODS Here, we examined the inflammatory reaction and autophagy in murine tri-cultures of neurons, astrocytes, and microglia. Tri-cultures were exposed to various inflammatory stresses (lipopolysaccharide (LPS), amyloid peptide (Aβ42) with or without cytokines) for 48 hours. Furthermore, the relationships between inflammation and autophagy were also analyzed in astrocyte- and microglia-enriched cultures. Data for multiple variable comparisons were analyzed by a one-way ANOVA followed by a Newman-keuls' test. RESULTS Aβ42 induced a low inflammation without accumulation of acidic vesicles contrary to moderate or severe inflammation induced by LPS or the cytokine cocktail (IL-1β, TNF-α, and IL-6) or IL-1β alone which led to co-localization of p62 and LC3, two markers of autophagy, with acidic vesicles stained with Lyso-ID Red dye. Moreover, the study reveals a major role of IL-1β in the induction of autophagy in tri-cultures in the presence or absence of Aβ42. However, the vulnerability of the autophagic process in purified microglia to IL-1β was prevented by Aβ42. CONCLUSION These findings show a close relationship between inflammation and autophagy, in particular a major role of IL-1β in the induction of the microglial autophagy which could be the case in AD. New therapeutic strategies could target inflammasome and autophagy in microglia to maintain its role in the amyloid immunosurveillance.
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Affiliation(s)
| | | | | | | | | | - Guylène Page
- EA3808 Molecular Targets and Therapeutic of Alzheimer's Disease, University of Poitiers, Poitiers F-86022, France.
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32
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Cheng T, Orlow SJ, Manga P. Loss of Oca2 disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes. Pigment Cell Melanoma Res 2013; 26:826-34. [PMID: 23962237 PMCID: PMC3832131 DOI: 10.1111/pcmr.12158] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 08/19/2013] [Indexed: 12/25/2022]
Abstract
Accumulation of proteins in the endoplasmic reticulum (ER) typically induces stress and initiates the unfolded protein response (UPR) to facilitate recovery. If homeostasis is not restored, apoptosis is induced. However, adaptation to chronic UPR activation can increase resistance to subsequent acute ER stress. We therefore investigated adaptive mechanisms in Oculocutaneous albinism type 2 (Oca2)-null melanocytes where UPR signaling is arrested despite continued tyrosinase accumulation leading to resistance to the chemical ER stressor thapsigargin. Although thapsigargin triggers UPR activation, instead of Perk-mediated phosphorylation of eIF2α, in Oca2-null melanocytes, eIF2α was rapidly dephosphorylated upon treatment. Dephosphorylation was mediated by the Gadd34-PP1α phosphatase complex. Gadd34-complex inhibition blocked eIF2α dephosphorylation and significantly increased Oca2-null melanocyte sensitivity to thapsigargin. Thus, Oca2-null melanocytes adapt to acute ER stress by disruption of pro-apoptotic Perk signaling, which promotes cell survival. This is the first study to demonstrate rapid eIF2α dephosphorylation as an adaptive mechanism to ER stress.
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Affiliation(s)
- Tsing Cheng
- The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA
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33
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Preston AM, Hendershot LM. Examination of a second node of translational control in the unfolded protein response. J Cell Sci 2013; 126:4253-61. [PMID: 23843622 DOI: 10.1242/jcs.130336] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The unfolded protein response (UPR) is a largely cytoprotective signaling cascade that acts to re-establish homeostasis of the endoplasmic reticulum (ER) under conditions of stress by inducing an early and transient block in general protein synthesis and by increasing the folding and degradative capacity of the cell through an extensive transcriptional program. It is well established that the mechanism for the early translational attenuation during ER stress occurs through phosphorylation of eukaryotic initiation factor 2 α (eIF2α) by activated PERK. Our data demonstrate that when eIF2α is dephosphorylated translation is not fully restored to pre-stressed levels. We found that this correlates with reduced mTOR activity and as a result decreases phosphorylation of 4E-BP1, which negatively regulates assembly of the eIF4F complex and cap-dependent translation. The decrease in mTOR activity and 4E-BP1 phosphorylation is associated with activation of AMP kinase, a negative regulator of mTOR, and in the case of some stress conditions, downregulation of signaling through key components of the PI3K pathway. Furthermore, we show that there is a subset of mRNAs that does not recover from UPR-induced translational repression, including those whose translation is particularly sensitive to loss of eIF4F, such as cyclin D1, Bcl-2 and MMP-9. Together these data implicate reduced mTOR activity and 4E-BP1 hypophosphorylation as a second, more restricted mechanism of translational control occurring somewhat later in the UPR.
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Affiliation(s)
- Amanda M Preston
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
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Soliman GA. The role of mechanistic target of rapamycin (mTOR) complexes signaling in the immune responses. Nutrients 2013; 5:2231-57. [PMID: 23783557 PMCID: PMC3725503 DOI: 10.3390/nu5062231] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/05/2013] [Accepted: 06/05/2013] [Indexed: 12/17/2022] Open
Abstract
The mechanistic Target of Rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase which is a member of the PI3K related kinase (PIKK) family. mTOR emerged as a central node in cellular metabolism, cell growth, and differentiation, as well as cancer metabolism. mTOR senses the nutrients, energy, insulin, growth factors, and environmental cues and transmits signals to downstream targets to effectuate the cellular and metabolic response. Recently, mTOR was also implicated in the regulation of both the innate and adaptive immune responses. This paper will summarize the current knowledge of mTOR, as related to the immune microenvironment and immune responses.
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Affiliation(s)
- Ghada A Soliman
- Department of Health Promotion, Social and Behavioral Health Sciences, College of Public Health, University of Nebraska Medical Center, 984365 Nebraska Medical Center, Omaha, NE 68198, USA.
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35
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Cláudio N, Dalet A, Gatti E, Pierre P. Mapping the crossroads of immune activation and cellular stress response pathways. EMBO J 2013; 32:1214-24. [PMID: 23584529 DOI: 10.1038/emboj.2013.80] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/15/2013] [Indexed: 12/14/2022] Open
Abstract
The innate immune cell network detects specific microbes and damages to cell integrity in order to coordinate and polarize the immune response against invading pathogens. In recent years, a cross-talk between microbial-sensing pathways and endoplasmic reticulum (ER) homeostasis has been discovered and have attracted the attention of many researchers from the inflammation field. Abnormal accumulation of proteins in the ER can be seen as a sign of cellular malfunction and triggers a collection of conserved emergency rescue pathways. These signalling cascades, which increase ER homeostasis and favour cell survival, are collectively known as the unfolded protein response (UPR). The induction or activation by microbial stimuli of several molecules linked to the ER stress response pathway have led to the conclusion that microbe sensing by immunocytes is generally associated with an UPR, which serves as a signal amplification cascade favouring inflammatory cytokines production. Induction of the UPR alone was shown to promote inflammation in different cellular and pathological models. Here we discuss how the innate immune and ER-signalling pathways intersect. Moreover, we propose that the induction of UPR-related molecules by microbial products does not necessarily reflect ER stress, but instead is an integral part of a specific transcription programme controlled by innate immunity receptors.
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Affiliation(s)
- Nuno Cláudio
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, Marseille, France
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36
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Plasma cells require autophagy for sustainable immunoglobulin production. Nat Immunol 2013; 14:298-305. [PMID: 23354484 DOI: 10.1038/ni.2524] [Citation(s) in RCA: 309] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/14/2012] [Indexed: 02/06/2023]
Abstract
The role of autophagy in plasma cells is unknown. Here we found notable autophagic activity in both differentiating and long-lived plasma cells and investigated its function through the use of mice with conditional deficiency in the essential autophagic molecule Atg5 in B cells. Atg5(-/-) differentiating plasma cells had a larger endoplasmic reticulum (ER) and more ER stress signaling than did their wild-type counterparts, which led to higher expression of the transcriptional repressor Blimp-1 and immunoglobulins and more antibody secretion. The enhanced immunoglobulin synthesis was associated with less intracellular ATP and more death of mutant plasma cells, which identified an unsuspected autophagy-dependent cytoprotective trade-off between immunoglobulin synthesis and viability. In vivo, mice with conditional deficiency in Atg5 in B cells had defective antibody responses, complete selection in the bone marrow for plasma cells that escaped Atg5 deletion and fewer antigen-specific long-lived bone marrow plasma cells than did wild-type mice, despite having normal germinal center responses. Thus, autophagy is specifically required for plasma cell homeostasis and long-lived humoral immunity.
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Bravo R, Parra V, Gatica D, Rodriguez AE, Torrealba N, Paredes F, Wang ZV, Zorzano A, Hill JA, Jaimovich E, Quest AFG, Lavandero S. Endoplasmic reticulum and the unfolded protein response: dynamics and metabolic integration. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 301:215-90. [PMID: 23317820 DOI: 10.1016/b978-0-12-407704-1.00005-1] [Citation(s) in RCA: 398] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) is a dynamic intracellular organelle with multiple functions essential for cellular homeostasis, development, and stress responsiveness. In response to cellular stress, a well-established signaling cascade, the unfolded protein response (UPR), is activated. This intricate mechanism is an important means of re-establishing cellular homeostasis and alleviating the inciting stress. Now, emerging evidence has demonstrated that the UPR influences cellular metabolism through diverse mechanisms, including calcium and lipid transfer, raising the prospect of involvement of these processes in the pathogenesis of disease, including neurodegeneration, cancer, diabetes mellitus and cardiovascular disease. Here, we review the distinct functions of the ER and UPR from a metabolic point of view, highlighting their association with prevalent pathologies.
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Affiliation(s)
- Roberto Bravo
- Center for Molecular Studies of the Cell, University of Chile, Santiago, Chile
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Prednisolone-induced beta cell dysfunction is associated with impaired endoplasmic reticulum homeostasis in INS-1E cells. Cell Signal 2011; 23:1708-15. [PMID: 21689745 DOI: 10.1016/j.cellsig.2011.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 06/06/2011] [Indexed: 12/25/2022]
Abstract
Glucocorticoids (GCs), such as prednisolone (PRED), are widely prescribed anti-inflammatory drugs, but their use may induce glucose intolerance and diabetes. GC-induced beta cell dysfunction contributes to these diabetogenic effects through mechanisms that remain to be elucidated. In this study, we hypothesized that activation of the unfolded protein response (UPR) following endoplasmic reticulum (ER) stress could be one of the underlying mechanisms involved in GC-induced beta cell dysfunction. We report here that PRED did not affect basal insulin release but time-dependently inhibited glucose-stimulated insulin secretion in INS-1E cells. PRED treatment also decreased both PDX1 and insulin expression, leading to a marked reduction in cellular insulin content. These PRED-induced detrimental effects were found to be prevented by prior treatment with the glucocorticoid receptor (GR) antagonist RU486 and associated with activation of two of the three branches of the UPR. Indeed, PRED induced a GR-mediated activation of both ATF6 and IRE1/XBP1 pathways but was found to reduce the phosphorylation of PERK and its downstream substrate eIF2α. These modulations of ER stress pathways were accompanied by upregulation of calpain 10 and increased cleaved caspase 3, indicating that long term exposure to PRED ultimately promotes apoptosis. Taken together, our data suggest that the inhibition of insulin biosynthesis by PRED in the insulin-secreting INS-1E cells results, at least in part, from a GR-mediated impairment in ER homeostasis which may lead to apoptotic cell death.
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