1
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Labbé K, LeBon L, King B, Vu N, Stoops EH, Ly N, Lefebvre AEYT, Seitzer P, Krishnan S, Heo JM, Bennett B, Sidrauski C. Specific activation of the integrated stress response uncovers regulation of central carbon metabolism and lipid droplet biogenesis. Nat Commun 2024; 15:8301. [PMID: 39333061 PMCID: PMC11436933 DOI: 10.1038/s41467-024-52538-5] [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: 04/26/2023] [Accepted: 09/10/2024] [Indexed: 09/29/2024] Open
Abstract
The integrated stress response (ISR) enables cells to cope with a variety of insults, but its specific contribution to downstream cellular outputs remains unclear. Using a synthetic tool, we selectively activate the ISR without co-activation of parallel pathways and define the resulting cellular state with multi-omics profiling. We identify time- and dose-dependent gene expression modules, with ATF4 driving only a small but sensitive subgroup that includes amino acid metabolic enzymes. This ATF4 response affects cellular bioenergetics, rerouting carbon utilization towards amino acid production and away from the tricarboxylic acid cycle and fatty acid synthesis. We also find an ATF4-independent reorganization of the lipidome that promotes DGAT-dependent triglyceride synthesis and accumulation of lipid droplets. While DGAT1 is the main driver of lipid droplet biogenesis, DGAT2 plays an essential role in buffering stress and maintaining cell survival. Together, we demonstrate the sufficiency of the ISR in promoting a previously unappreciated metabolic state.
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Affiliation(s)
| | - Lauren LeBon
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | - Bryan King
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | - Ngoc Vu
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | | | - Nina Ly
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | | | | | | | - Jin-Mi Heo
- Calico Life Sciences LLC, South San Francisco, CA, USA
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2
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Hanson FM, Ribeiro de Oliveira MI, Cross AK, Allen KE, Campbell SG. eIF2B localization and its regulation during the integrated stress response is cell-type specific. iScience 2024; 27:110851. [PMID: 39310746 PMCID: PMC11414691 DOI: 10.1016/j.isci.2024.110851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/30/2024] [Accepted: 08/27/2024] [Indexed: 09/25/2024] Open
Abstract
Eukaryotic initiation factor 2B (eIF2B) controls translation initiation by recycling inactive eIF2-GDP to active eIF2-GTP. Under cellular stress, the integrated stress response (ISR) is activated inhibiting eIF2B activity resulting in the translation attenuation and reprogramming of gene expression to overcome the stress. The ISR can dictate cell fate wherein chronic activation has pathological outcomes. Vanishing white matter disease (VWMD) is a chronic ISR-related disorder with mutations in eIF2B targeting astrocyte and oligodendrocyte cells. Regulation of eIF2B localization (eIF2B bodies) has been implicated in the ISR. We present evidence that neuronal and glial cell types possess distinct patterns of eIF2B bodies which change in a manner correlating to acute and chronic ISR activation. We also demonstrate that while neural and glial cell types respond similarly to the acute induction of the ISR a chronic ISR exerts cell-type specific differences. These findings provide key insights into neural cell responses and adaptation to cellular stress.
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Affiliation(s)
- Filipe M. Hanson
- Biomolecular Sciences Research Centre, Industry and Innovation Research Institute (IRI), Sheffield Hallam University, Sheffield S1 1WB, UK
| | - Madalena I. Ribeiro de Oliveira
- Biomolecular Sciences Research Centre, Industry and Innovation Research Institute (IRI), Sheffield Hallam University, Sheffield S1 1WB, UK
| | - Alison K. Cross
- Biomolecular Sciences Research Centre, Industry and Innovation Research Institute (IRI), Sheffield Hallam University, Sheffield S1 1WB, UK
| | - K. Elizabeth Allen
- Biomolecular Sciences Research Centre, Industry and Innovation Research Institute (IRI), Sheffield Hallam University, Sheffield S1 1WB, UK
| | - Susan G. Campbell
- Biomolecular Sciences Research Centre, Industry and Innovation Research Institute (IRI), Sheffield Hallam University, Sheffield S1 1WB, UK
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3
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Yulyaningsih E, Suh JH, Fanok M, Chau R, Solanoy H, Takahashi R, Bakardjiev AI, Becerra I, Benitez NB, Chiu CL, Davis SS, Dowdle WE, Earr T, Estrada AA, Gill A, Ha C, Haddick PCG, Henne KR, Larhammar M, Leung AWS, Maciuca R, Memarzadeh B, Nguyen HN, Nugent AA, Osipov M, Ran Y, Rebadulla K, Roche E, Sandmann T, Wang J, Lewcock JW, Scearce-Levie K, Kane LA, Sanchez PE. DNL343 is an investigational CNS penetrant eukaryotic initiation factor 2B activator that prevents and reverses the effects of neurodegeneration caused by the integrated stress response. eLife 2024; 12:RP92173. [PMID: 39287504 PMCID: PMC11407769 DOI: 10.7554/elife.92173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2024] Open
Abstract
The integrated stress response (ISR) is a conserved pathway in eukaryotic cells that is activated in response to multiple sources of cellular stress. Although acute activation of this pathway restores cellular homeostasis, intense or prolonged ISR activation perturbs cell function and may contribute to neurodegeneration. DNL343 is an investigational CNS-penetrant small-molecule ISR inhibitor designed to activate the eukaryotic initiation factor 2B (eIF2B) and suppress aberrant ISR activation. DNL343 reduced CNS ISR activity and neurodegeneration in a dose-dependent manner in two established in vivo models - the optic nerve crush injury and an eIF2B loss of function (LOF) mutant - demonstrating neuroprotection in both and preventing motor dysfunction in the LOF mutant mouse. Treatment with DNL343 at a late stage of disease in the LOF model reversed elevation in plasma biomarkers of neuroinflammation and neurodegeneration and prevented premature mortality. Several proteins and metabolites that are dysregulated in the LOF mouse brains were normalized by DNL343 treatment, and this response is detectable in human biofluids. Several of these biomarkers show differential levels in CSF and plasma from patients with vanishing white matter disease (VWMD), a neurodegenerative disease that is driven by eIF2B LOF and chronic ISR activation, supporting their potential translational relevance. This study demonstrates that DNL343 is a brain-penetrant ISR inhibitor capable of attenuating neurodegeneration in mouse models and identifies several biomarker candidates that may be used to assess treatment responses in the clinic.
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Affiliation(s)
| | - Jung H Suh
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | - Roni Chau
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | | | | | | | | | - Chi-Lu Chiu
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | | | - Timothy Earr
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | - Audrey Gill
- Denali TherapeuticsSouth San FranciscoUnited States
| | - Connie Ha
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | - Kirk R Henne
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | | | | | | | | | | | | | - Yingqing Ran
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | - Elysia Roche
- Denali TherapeuticsSouth San FranciscoUnited States
| | | | - Jing Wang
- Denali TherapeuticsSouth San FranciscoUnited States
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4
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Darawshi O, Yassin O, Shmuel M, Wek RC, Mahdizadeh SJ, Eriksson LA, Hatzoglou M, Tirosh B. Phosphorylation of GCN2 by mTOR confers adaptation to conditions of hyper-mTOR activation under stress. J Biol Chem 2024; 300:107575. [PMID: 39013537 PMCID: PMC11362803 DOI: 10.1016/j.jbc.2024.107575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 07/02/2024] [Accepted: 07/05/2024] [Indexed: 07/18/2024] Open
Abstract
Adaptation to the shortage in free amino acids (AA) is mediated by 2 pathways, the integrated stress response (ISR) and the mechanistic target of rapamycin (mTOR). In response to reduced levels, primarily of leucine or arginine, mTOR in its complex 1 configuration (mTORC1) is suppressed leading to a decrease in translation initiation and elongation. The eIF2α kinase general control nonderepressible 2 (GCN2) is activated by uncharged tRNAs, leading to induction of the ISR in response to a broader range of AA shortage. ISR confers a reduced translation initiation, while promoting the selective synthesis of stress proteins, such as ATF4. To efficiently adapt to AA starvation, the 2 pathways are cross-regulated at multiple levels. Here we identified a new mechanism of ISR/mTORC1 crosstalk that optimizes survival under AA starvation, when mTORC1 is forced to remain active. mTORC1 activation during acute AA shortage, augmented ATF4 expression in a GCN2-dependent manner. Under these conditions, enhanced GCN2 activity was not dependent on tRNA sensing, inferring a different activation mechanism. We identified a labile physical interaction between GCN2 and mTOR that results in a phosphorylation of GCN2 on serine 230 by mTOR, which promotes GCN2 activity. When examined under prolonged AA starvation, GCN2 phosphorylation by mTOR promoted survival. Our data unveils an adaptive mechanism to AA starvation, when mTORC1 evades inhibition.
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Affiliation(s)
- Odai Darawshi
- The School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Olaya Yassin
- The School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Miri Shmuel
- The School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - S Jalil Mahdizadeh
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Boaz Tirosh
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA.
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5
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Konstantinidou M, Arkin MR. Molecular glues for protein-protein interactions: Progressing toward a new dream. Cell Chem Biol 2024; 31:1064-1088. [PMID: 38701786 PMCID: PMC11193649 DOI: 10.1016/j.chembiol.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/08/2024] [Accepted: 04/08/2024] [Indexed: 05/05/2024]
Abstract
The modulation of protein-protein interactions with small molecules is one of the most rapidly developing areas in drug discovery. In this review, we discuss advances over the past decade (2014-2023) focusing on molecular glues (MGs)-monovalent small molecules that induce proximity, either by stabilizing native interactions or by inducing neomorphic interactions. We include both serendipitous and rational discoveries and describe the different approaches that were used to identify them. We classify the compounds in three main categories: degradative MGs, non-degradative MGs or PPI stabilizers, and MGs that induce self-association. Diverse, illustrative examples with structural data are described in detail, emphasizing the elements of molecular recognition and cooperative binding at the interface that are fundamental for a MG mechanism of action.
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Affiliation(s)
- Markella Konstantinidou
- Department of Pharmaceutical Chemistry and Small Molecule Discovery Center (SMDC), University of California, San Francisco, San Francisco, CA 94143, USA
| | - Michelle R Arkin
- Department of Pharmaceutical Chemistry and Small Molecule Discovery Center (SMDC), University of California, San Francisco, San Francisco, CA 94143, USA.
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6
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Pei Y, Liu S, Wang L, Chen C, Hu M, Xue Y, Guan D, Xie L, Liao H, Zhou J, Zhang H. Design, Synthesis, and Biological Evaluation of Eukaryotic Initiation Factor 2B (eIF2B) Activators. ChemMedChem 2024; 19:e202300716. [PMID: 38426720 DOI: 10.1002/cmdc.202300716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/29/2024] [Accepted: 02/29/2024] [Indexed: 03/02/2024]
Abstract
The eukaryotic initiation factor 2B (eIF2B) is a key regulator in protein-regulated signaling pathways and is closely related to the function of the central nervous system. Modulating eIF2B could retard the process of neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and vanishing white matter disease (VWM) et al. Here, we designed and synthesized a series of novel eIF2B activators containing oxadiazole fragments. The activating effects of compounds on eIF2B were investigated through testing the inhibition of ATF4 expression. Of all the targeted compounds, compounds 21 and 29 exhibited potent inhibition on ATF4 expression with IC50 values of 32.43 nM and 47.71 nM, respectively, which were stronger than that of ISRIB (IC50=67.90 nM). ATF4 mRNA assay showed that these two compounds could restore ATF4 mRNA to normal levels in thapsigargin-stimulated HeLa cells. Protein Translation assay showed that both compounds were effective in restoring protein synthesis. Compound potency assay showed that both compounds had similar potency to ISRIB with EC50 values of 5.844 and 37.70 nM. Cytotoxicity assay revealed that compounds 21 and 29 had low toxicity and were worth further investigation.
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Affiliation(s)
- Yifeng Pei
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Sentao Liu
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Lixun Wang
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Chao Chen
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Mengqiu Hu
- New Drug Screening Center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing, China
| | - Yi Xue
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Dezhong Guan
- Department of Medicinal Chemistry, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, PR China
| | - Lingfeng Xie
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Hong Liao
- New Drug Screening Center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing, China
| | - Jinpei Zhou
- Department of Medicinal Chemistry, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, PR China
| | - Huibin Zhang
- Center for Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, 210009, PR China
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7
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Lu HJ, Koju N, Sheng R. Mammalian integrated stress responses in stressed organelles and their functions. Acta Pharmacol Sin 2024; 45:1095-1114. [PMID: 38267546 PMCID: PMC11130345 DOI: 10.1038/s41401-023-01225-0] [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: 06/29/2023] [Accepted: 12/30/2023] [Indexed: 01/26/2024] Open
Abstract
The integrated stress response (ISR) triggered in response to various cellular stress enables mammalian cells to effectively cope with diverse stressful conditions while maintaining their normal functions. Four kinases (PERK, PKR, GCN2, and HRI) of ISR regulate ISR signaling and intracellular protein translation via mediating the phosphorylation of eukaryotic translation initiation factor 2 α (eIF2α) at Ser51. Early ISR creates an opportunity for cells to repair themselves and restore homeostasis. This effect, however, is reversed in the late stages of ISR. Currently, some studies have shown the non-negligible impact of ISR on diseases such as ischemic diseases, cognitive impairment, metabolic syndrome, cancer, vanishing white matter, etc. Hence, artificial regulation of ISR and its signaling with ISR modulators becomes a promising therapeutic strategy for relieving disease symptoms and improving clinical outcomes. Here, we provide an overview of the essential mechanisms of ISR and describe the ISR-related pathways in organelles including mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes. Meanwhile, the regulatory effects of ISR modulators and their potential application in various diseases are also enumerated.
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Affiliation(s)
- Hao-Jun Lu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China
| | - Nirmala Koju
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China
| | - Rui Sheng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China.
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8
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Solorio-Kirpichyan K, Fan X, Golovenko D, Korostelev AA, Yan N, Korennykh A. Cryo-EM Structure of HRSL Domain Reveals Activating Crossed Helices at the Core of GCN2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.591037. [PMID: 38712127 PMCID: PMC11071503 DOI: 10.1101/2024.04.24.591037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
GCN2 is a conserved receptor kinase activating the Integrated Stress Response (ISR) in eukaryotic cells. The ISR kinases detect accumulation of stress molecules and reprogram translation from basal tasks to preferred production of cytoprotective proteins. GCN2 stands out evolutionarily among all protein kinases due to the presence of a h istidyl t R NA s ynthetase-like (HRSL) domain, which arises only in GCN2 and is located next to the kinase domain. How HRSL contributes to GCN2 signaling remains unknown. Here we report a 3.2 Å cryo-EM structure of HRSL from thermotolerant yeast Kluyveromyces marxianus . This structure shows a constitutive symmetrical homodimer featuring a compact helical-bundle structure at the junction between HRSL and kinase domains, in the core of the receptor. Mutagenesis demonstrates that this junction structure activates GCN2 and indicates that our cryo-EM structure captures the active signaling state of HRSL. Based on these results, we put forward a GCN2 regulation mechanism, where HRSL drives the formation of activated kinase dimers. Remaining domains of GCN2 have the opposite role and in the absence of stress they help keep GCN2 basally inactive. This autoinhibitory activity is relieved upon stress ligand binding. We propose that the opposing action of HRSL and additional GCN2 domains thus yields a regulated ISR receptor. Significance statement Regulation of protein synthesis (translation) is a central mechanism by which eukaryotic cells adapt to stressful conditions. In starving cells, this translational adaptation is achieved via the receptor kinase GCN2, which stays inactive under normal conditions, but is switched on under stress. The molecular mechanism of GCN2 switching is not well understood due to the presence of a structurally and biochemically uncharacterized h istidyl t R NA s ynthetase-like domain (HRSL) at the core of GCN2. Here we use single-particle cryo-EM and biochemistry to elucidate the structure and function of HRSL. We identify a structure at the kinase/HRSL interface, which forms crossed helices and helps position GCN2 kinase domains for activation. These data clarify the molecular mechanism of GCN2 regulation.
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9
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Coulson RL, Frattini V, Moyer CE, Hodges J, Walter P, Mourrain P, Zuo Y, Wang GX. Translational modulator ISRIB alleviates synaptic and behavioral phenotypes in Fragile X syndrome. iScience 2024; 27:109259. [PMID: 38510125 PMCID: PMC10951902 DOI: 10.1016/j.isci.2024.109259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/31/2023] [Accepted: 02/13/2024] [Indexed: 03/22/2024] Open
Abstract
Fragile X syndrome (FXS) is caused by the loss of fragile X messenger ribonucleoprotein (FMRP), a translational regulator that binds the transcripts of proteins involved in synaptic function and plasticity. Dysregulated protein synthesis is a central effect of FMRP loss, however, direct translational modulation has not been leveraged in the treatment of FXS. Thus, we examined the effect of the translational modulator integrated stress response inhibitor (ISRIB) in treating synaptic and behavioral symptoms of FXS. We show that FMRP loss dysregulates synaptic protein abundance, stabilizing dendritic spines through increased PSD-95 levels while preventing spine maturation through reduced glutamate receptor accumulation, thus leading to the formation of dense, immature dendritic spines, characteristic of FXS patients and Fmr1 knockout (KO) mice. ISRIB rescues these deficits and improves social recognition in Fmr1 KO mice. These findings highlight the therapeutic potential of targeting core translational mechanisms in FXS and neurodevelopmental disorders more broadly.
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Affiliation(s)
- Rochelle L. Coulson
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Valentina Frattini
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Caitlin E. Moyer
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jennifer Hodges
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Peter Walter
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94143, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94143, USA
| | - Philippe Mourrain
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
- INSERM 1024, Ecole Normale Supérieure, Paris, France
| | - Yi Zuo
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Gordon X. Wang
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
- Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA 94305, USA
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10
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Craig RA, De Vicente J, Estrada AA, Feng JA, Lexa KW, Canet MJ, Dowdle WE, Erickson RI, Flores BN, Haddick PCG, Kane LA, Lewcock JW, Moerke NJ, Poda SB, Sweeney Z, Takahashi RH, Tong V, Wang J, Yulyaningsih E, Solanoy H, Scearce-Levie K, Sanchez PE, Tang L, Xu M, Zhang R, Osipov M. Discovery of DNL343: A Potent, Selective, and Brain-Penetrant eIF2B Activator Designed for the Treatment of Neurodegenerative Diseases. J Med Chem 2024; 67:5758-5782. [PMID: 38511649 DOI: 10.1021/acs.jmedchem.3c02422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Eukaryotic translation initiation factor 2B (eIF2B) is a key component of the integrated stress response (ISR), which regulates protein synthesis and stress granule formation in response to cellular insult. Modulation of the ISR has been proposed as a therapeutic strategy for treatment of neurodegenerative diseases such as vanishing white matter (VWM) disease and amyotrophic lateral sclerosis (ALS) based on its ability to improve cellular homeostasis and prevent neuronal degeneration. Herein, we report the small-molecule discovery campaign that identified potent, selective, and CNS-penetrant eIF2B activators using both structure- and ligand-based drug design. These discovery efforts culminated in the identification of DNL343, which demonstrated a desirable preclinical drug profile, including a long half-life and high oral bioavailability across preclinical species. DNL343 was progressed into clinical studies and is currently undergoing evaluation in late-stage clinical trials for ALS.
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Affiliation(s)
- Robert A Craig
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Javier De Vicente
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Anthony A Estrada
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Jianwen A Feng
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Katrina W Lexa
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Mark J Canet
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - William E Dowdle
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Rebecca I Erickson
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Brittany N Flores
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Patrick C G Haddick
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Lesley A Kane
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Joseph W Lewcock
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Nathan J Moerke
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Suresh B Poda
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Zachary Sweeney
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Ryan H Takahashi
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Vincent Tong
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Jing Wang
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Ernie Yulyaningsih
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Hilda Solanoy
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | | | - Pascal E Sanchez
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
| | - Liwei Tang
- Department of Chemistry, WuXi AppTec Co., Ltd., Tianjin 300457, China
| | - Musheng Xu
- Department of Chemistry, WuXi AppTec Co., Ltd., Tianjin 300457, China
| | - Rui Zhang
- Department of Chemistry, WuXi AppTec Co., Ltd., Tianjin 300457, China
| | - Maksim Osipov
- Denali Therapeutics Inc., South San Francisco, California 94080, United States
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11
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Kashiwagi K, Ito T. Switching on stress. Nat Chem Biol 2024; 20:394-395. [PMID: 37945895 DOI: 10.1038/s41589-023-01436-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Affiliation(s)
- Kazuhiro Kashiwagi
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama, Japan
| | - Takuhiro Ito
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama, Japan.
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12
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Lawrence RE, Shoemaker SR, Deal A, Sangwan S, Anand AA, Wang L, Marqusee S, Walter P. A helical fulcrum in eIF2B coordinates allosteric regulation of stress signaling. Nat Chem Biol 2024; 20:422-431. [PMID: 37945896 PMCID: PMC10972756 DOI: 10.1038/s41589-023-01453-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 09/17/2023] [Indexed: 11/12/2023]
Abstract
The integrated stress response (ISR) enables cells to survive a variety of acute stresses, but chronic activation of the ISR underlies age-related diseases. ISR signaling downregulates translation and activates expression of stress-responsive factors that promote return to homeostasis and is initiated by inhibition of the decameric guanine nucleotide exchange factor eIF2B. Conformational and assembly transitions regulate eIF2B activity, but the allosteric mechanisms controlling these dynamic transitions and mediating the therapeutic effects of the small-molecule ISR inhibitor ISRIB are unknown. Using hydrogen-deuterium exchange-mass spectrometry and cryo-electron microscopy, we identified a central α-helix whose orientation allosterically coordinates eIF2B conformation and assembly. Biochemical and cellular signaling assays show that this 'switch-helix' controls eIF2B activity and signaling. In sum, the switch-helix acts as a fulcrum of eIF2B conformational regulation and is a highly conserved actuator of ISR signal transduction. This work uncovers a conserved allosteric mechanism and unlocks new therapeutic possibilities for ISR-linked diseases.
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Affiliation(s)
- Rosalie E Lawrence
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
| | - Sophie R Shoemaker
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Aniliese Deal
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
- Altos Laboratories, Bay Area Institute of Science, Redwood City, CA, USA
| | - Smriti Sangwan
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Aditya A Anand
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
- Genentech, Inc., South San Francisco, CA, USA
| | - Lan Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
- The Hong Kong University of Science and Technology, Hong Kong, Hong Kong.
| | - Susan Marqusee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA.
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
- Altos Laboratories, Bay Area Institute of Science, Redwood City, CA, USA.
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13
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Brito Querido J, Díaz-López I, Ramakrishnan V. The molecular basis of translation initiation and its regulation in eukaryotes. Nat Rev Mol Cell Biol 2024; 25:168-186. [PMID: 38052923 DOI: 10.1038/s41580-023-00624-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2023] [Indexed: 12/07/2023]
Abstract
The regulation of gene expression is fundamental for life. Whereas the role of transcriptional regulation of gene expression has been studied for several decades, it has been clear over the past two decades that post-transcriptional regulation of gene expression, of which translation regulation is a major part, can be equally important. Translation can be divided into four main stages: initiation, elongation, termination and ribosome recycling. Translation is controlled mainly during its initiation, a process which culminates in a ribosome positioned with an initiator tRNA over the start codon and, thus, ready to begin elongation of the protein chain. mRNA translation has emerged as a powerful tool for the development of innovative therapies, yet the detailed mechanisms underlying the complex process of initiation remain unclear. Recent studies in yeast and mammals have started to shed light on some previously unclear aspects of this process. In this Review, we discuss the current state of knowledge on eukaryotic translation initiation and its regulation in health and disease. Specifically, we focus on recent advances in understanding the processes involved in assembling the 43S pre-initiation complex and its recruitment by the cap-binding complex eukaryotic translation initiation factor 4F (eIF4F) at the 5' end of mRNA. In addition, we discuss recent insights into ribosome scanning along the 5' untranslated region of mRNA and selection of the start codon, which culminates in joining of the 60S large subunit and formation of the 80S initiation complex.
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Affiliation(s)
- Jailson Brito Querido
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Irene Díaz-López
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
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14
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Yan G, Han Z, Kwon Y, Jousma J, Nukala SB, Prosser BL, Du X, Pinho S, Ong SB, Lee WH, Ong SG. Integrated Stress Response Potentiates Ponatinib-Induced Cardiotoxicity. Circ Res 2024; 134:482-501. [PMID: 38323474 PMCID: PMC10940206 DOI: 10.1161/circresaha.123.323683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND Mitochondrial dysfunction is a primary driver of cardiac contractile failure; yet, the cross talk between mitochondrial energetics and signaling regulation remains obscure. Ponatinib, a tyrosine kinase inhibitor used to treat chronic myeloid leukemia, is among the most cardiotoxic tyrosine kinase inhibitors and causes mitochondrial dysfunction. Whether ponatinib-induced mitochondrial dysfunction triggers the integrated stress response (ISR) to induce ponatinib-induced cardiotoxicity remains to be determined. METHODS Using human induced pluripotent stem cells-derived cardiomyocytes and a recently developed mouse model of ponatinib-induced cardiotoxicity, we performed proteomic analysis, molecular and biochemical assays to investigate the relationship between ponatinib-induced mitochondrial stress and ISR and their role in promoting ponatinib-induced cardiotoxicity. RESULTS Proteomic analysis revealed that ponatinib activated the ISR in cardiac cells. We identified GCN2 (general control nonderepressible 2) as the eIF2α (eukaryotic translation initiation factor 2α) kinase responsible for relaying mitochondrial stress signals to trigger the primary ISR effector-ATF4 (activating transcription factor 4), upon ponatinib exposure. Mechanistically, ponatinib treatment exerted inhibitory effects on ATP synthase activity and reduced its expression levels resulting in ATP deficits. Perturbed mitochondrial function resulting in ATP deficits then acts as a trigger of GCN2-mediated ISR activation, effects that were negated by nicotinamide mononucleotide, an NAD+ precursor, supplementation. Genetic inhibition of ATP synthase also activated GCN2. Interestingly, we showed that the decreased abundance of ATP also facilitated direct binding of ponatinib to GCN2, unexpectedly causing its activation most likely because of a conformational change in its structure. Importantly, administering an ISR inhibitor protected human induced pluripotent stem cell-derived cardiomyocytes against ponatinib. Ponatinib-treated mice also exhibited reduced cardiac function, effects that were attenuated upon systemic ISRIB administration. Importantly, ISRIB does not affect the antitumor effects of ponatinib in vitro. CONCLUSIONS Neutralizing ISR hyperactivation could prevent or reverse ponatinib-induced cardiotoxicity. The findings that compromised ATP production potentiates GCN2-mediated ISR activation have broad implications across various cardiac diseases. Our results also highlight an unanticipated role of ponatinib in causing direct activation of a kinase target despite its role as an ATP-competitive kinase inhibitor.
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Affiliation(s)
- Gege Yan
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Zhenbo Han
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Youjeong Kwon
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Jordan Jousma
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Sarath Babu Nukala
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xiaoping Du
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Sandra Pinho
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
| | - Sang-Bing Ong
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong (CUHK), Hong Kong SAR, China
- Centre for Cardiovascular Genomics and Medicine (CCGM), Lui Che Woo Institute of Innovative Medicine, CUHK, Hong Kong SAR, China
- Hong Kong Hub of Pediatric Excellence (HK HOPE), Hong Kong Children’s Hospital (HKCH), Kowloon Bay, Hong Kong SAR, China
- Kunming Institute of Zoology – The Chinese University of Hong Kong (KIZ-CUHK) Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Neural, Vascular, and Metabolic Biology Thematic Research Program, School of Biomedical Sciences (SBS), Chinese University of Hong Kong (CUHK), Hong Kong SAR, China
| | - Won Hee Lee
- Department of Basic Medical Sciences, University of Arizona College of Medicine, Phoenix, USA
| | - Sang-Ging Ong
- Department of Pharmacology & Regenerative Medicine, University of Illinois College of Medicine, Chicago, USA
- Division of Cardiology, Department of Medicine, University of Illinois College of Medicine, Chicago, USA
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15
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Yousuf MS, Sahn JJ, Yang H, David ET, Shiers S, Mancilla Moreno M, Iketem J, Royer DM, Garcia CD, Zhang J, Hong VM, Mian SM, Ahmad A, Kolber BJ, Liebl DJ, Martin SF, Price TJ. Highly specific σ 2R/TMEM97 ligand FEM-1689 alleviates neuropathic pain and inhibits the integrated stress response. Proc Natl Acad Sci U S A 2023; 120:e2306090120. [PMID: 38117854 PMCID: PMC10756276 DOI: 10.1073/pnas.2306090120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 11/21/2023] [Indexed: 12/22/2023] Open
Abstract
The sigma 2 receptor (σ2R) was described pharmacologically more than three decades ago, but its molecular identity remained obscure until recently when it was identified as transmembrane protein 97 (TMEM97). We and others have shown that σ2R/TMEM97 ligands alleviate mechanical hypersensitivity in mouse neuropathic pain models with a time course wherein maximal antinociceptive effect is approximately 24 h following dosing. We sought to understand this unique antineuropathic pain effect by addressing two key questions: do these σ2R/TMEM97 compounds act selectively via the receptor, and what is their downstream mechanism on nociceptive neurons? Using male and female conventional knockout mice for Tmem97, we find that a σ2R/TMEM97 binding compound, FEM-1689, requires the presence of the gene to produce antinociception in the spared nerve injury model in mice. Using primary mouse dorsal root ganglion neurons, we demonstrate that FEM-1689 inhibits the integrated stress response (ISR) and promotes neurite outgrowth via a σ2R/TMEM97-specific action. We extend the clinical translational value of these findings by showing that FEM-1689 reduces ISR and p-eIF2α levels in human sensory neurons and that it alleviates the pathogenic engagement of ISR by methylglyoxal. We also demonstrate that σ2R/TMEM97 is expressed in human nociceptors and satellite glial cells. These results validate σ2R/TMEM97 as a promising target for further development for the treatment of neuropathic pain.
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Affiliation(s)
- Muhammad Saad Yousuf
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
- NuvoNuro Inc., Austin, TX78712
| | - James J. Sahn
- NuvoNuro Inc., Austin, TX78712
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Hongfen Yang
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Eric T. David
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Stephanie Shiers
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Marisol Mancilla Moreno
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Jonathan Iketem
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Danielle M. Royer
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Chelsea D. Garcia
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Jennifer Zhang
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Veronica M. Hong
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Subhaan M. Mian
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Ayesha Ahmad
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Benedict J. Kolber
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
| | - Daniel J. Liebl
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL33136
| | - Stephen F. Martin
- NuvoNuro Inc., Austin, TX78712
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Theodore J. Price
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX75080
- NuvoNuro Inc., Austin, TX78712
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16
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Perea V, Baron KR, Dolina V, Aviles G, Kim G, Rosarda JD, Guo X, Kampmann M, Wiseman RL. Pharmacologic activation of a compensatory integrated stress response kinase promotes mitochondrial remodeling in PERK-deficient cells. Cell Chem Biol 2023; 30:1571-1584.e5. [PMID: 37922906 PMCID: PMC10842031 DOI: 10.1016/j.chembiol.2023.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/21/2023] [Accepted: 10/10/2023] [Indexed: 11/07/2023]
Abstract
The integrated stress response (ISR) comprises the eIF2α kinases PERK, GCN2, HRI, and PKR, which induce translational and transcriptional signaling in response to diverse insults. Deficiencies in PERK signaling lead to mitochondrial dysfunction and contribute to the pathogenesis of numerous diseases. We define the potential for pharmacologic activation of compensatory eIF2α kinases to rescue ISR signaling and promote mitochondrial adaptation in PERK-deficient cells. We show that the HRI activator BtdCPU and GCN2 activator halofuginone promote ISR signaling and rescue ER stress sensitivity in PERK-deficient cells. However, BtdCPU induces mitochondrial depolarization, leading to mitochondrial fragmentation and activation of the OMA1-DELE1-HRI signaling axis. In contrast, halofuginone promotes mitochondrial elongation and adaptive mitochondrial respiration, mimicking regulation induced by PERK. This shows halofuginone can compensate for deficiencies in PERK signaling and promote adaptive mitochondrial remodeling, highlighting the potential for pharmacologic ISR activation to mitigate mitochondrial dysfunction and motivating the pursuit of highly selective ISR activators.
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Affiliation(s)
- Valerie Perea
- Department of Molecular and Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kelsey R Baron
- Department of Molecular and Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Vivian Dolina
- Department of Molecular and Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Giovanni Aviles
- Department of Biophysics and Biochemistry and Institute for Neurodegenerative Diseases, UCSF, San Francisco, CA 94158, USA
| | - Grace Kim
- Department of Molecular and Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jessica D Rosarda
- Department of Molecular and Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Xiaoyan Guo
- Department of Biophysics and Biochemistry and Institute for Neurodegenerative Diseases, UCSF, San Francisco, CA 94158, USA; Department of Genetics and Genome Sciences, University of Connecticut Health, Farmington, CT 06030, USA
| | - Martin Kampmann
- Department of Biophysics and Biochemistry and Institute for Neurodegenerative Diseases, UCSF, San Francisco, CA 94158, USA
| | - R Luke Wiseman
- Department of Molecular and Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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17
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Münch C, Kirstein J. Protein quality control: from molecular mechanisms to therapeutic intervention-EMBO workshop, May 21-26 2023, Srebreno, Croatia. Cell Stress Chaperones 2023; 28:631-640. [PMID: 37731161 PMCID: PMC10746685 DOI: 10.1007/s12192-023-01383-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/22/2023] Open
Abstract
Protein quality control pathways ensure a functional proteome and rely on a complex proteostasis network (PN) that is composed of molecular chaperones and proteases. Failures in the PN can lead to a broad spectrum of diseases, including neurodegenerative disorders like Alzheimer's, Parkinson's, and a range of motor neuron diseases. The EMBO workshop "Protein quality control: from molecular mechanisms to therapeutic intervention" covered all aspects of protein quality control from underlying molecular mechanisms of chaperones and proteases to stress signaling pathways and medical implications. This report summarizes the workshop and highlights selected presentations.
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Affiliation(s)
- Christian Münch
- Institute of Biochemistry II, Medical Faculty, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Janine Kirstein
- Friedrich-Schiller-Universität Jena, Jena, Germany.
- Leibniz-Institute on Aging/Fritz-Lipmann Institute, Jena, Germany.
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18
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Izumi Y, O'Dell KA, Zorumski CF. The herbicide glyphosate inhibits hippocampal long-term potentiation and learning through activation of pro-inflammatory signaling. Sci Rep 2023; 13:18005. [PMID: 37865669 PMCID: PMC10590375 DOI: 10.1038/s41598-023-44121-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 10/04/2023] [Indexed: 10/23/2023] Open
Abstract
Glyphosate, a herbicide marketed as Roundup, is widely used but there are concerns this exposure could impair cognitive function. In the CA1 region of rat hippocampal slices, we investigated whether glyphosate alters synaptic transmission and long-term potentiation (LTP), a cellular model of learning and memory. Our hypothesis is that glyphosate alters neuronal function and impairs LTP induction via activation of pro-inflammatory processes. Roundup depressed excitatory synaptic potentials(EPSPs) in a dose-dependent manner with complete suppression at 2000 mg/L. At concentrations ≤ 20 mg/L Roundup did not affect basal transmission, but 4 mg/L Roundup administered for 30 min inhibited LTP induction. Acute administration of 10-100 μM glyphosate also inhibited LTP induction. Minocycline, an inhibitor of microglial activation, and TAK-242, an inhibitor of toll-like receptor 4 (TLR4), both overcame the inhibitory effects of 100 µM glyphosate. Similarly, lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS), a different TLR4 antagonist, overcame the inhibitory effects. In addition, ISRIB (integrated stress response inhibitor) and quercetin, an inhibitor of endoplasmic reticulum stress, overcame the inhibitory effects. We also observed that in vivo glyphosate injection (16.9 mg/kg i.p.) impaired one-trial inhibitory avoidance learning. This learning deficit was overcome by TAK-242. These observations indicate that glyphosate can impair cognitive function through pro-inflammatory signaling in microglia.
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Affiliation(s)
- Yukitoshi Izumi
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA.
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.
| | - Kazuko A O'Dell
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F Zorumski
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
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19
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Fu Y, Sacco O, DeBitetto E, Kanshin E, Ueberheide B, Sfeir A. Mitochondrial DNA breaks activate an integrated stress response to reestablish homeostasis. Mol Cell 2023; 83:3740-3753.e9. [PMID: 37832546 PMCID: PMC11229056 DOI: 10.1016/j.molcel.2023.09.026] [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: 02/17/2023] [Revised: 08/10/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023]
Abstract
Mitochondrial DNA double-strand breaks (mtDSBs) lead to the degradation of circular genomes and a reduction in copy number; yet, the cellular response in human cells remains elusive. Here, using mitochondrial-targeted restriction enzymes, we show that a subset of cells with mtDSBs exhibited defective mitochondrial protein import, reduced respiratory complexes, and loss of membrane potential. Electron microscopy confirmed the altered mitochondrial membrane and cristae ultrastructure. Intriguingly, mtDSBs triggered the integrated stress response (ISR) via the phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) by DELE1 and heme-regulated eIF2α kinase (HRI). When ISR was inhibited, the cells experienced intensified mitochondrial defects and slower mtDNA recovery post-breakage. Lastly, through proteomics, we identified ATAD3A-a membrane-bound protein interacting with nucleoids-as potentially pivotal in relaying signals from impaired genomes to the inner mitochondrial membrane. In summary, our study delineates the cascade connecting damaged mitochondrial genomes to the cytoplasm and highlights the significance of the ISR in maintaining mitochondrial homeostasis amid genome instability.
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Affiliation(s)
- Yi Fu
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU School of Medicine, New York, NY 10016, USA; Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Olivia Sacco
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Emily DeBitetto
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Evgeny Kanshin
- Proteomics Laboratory, NYU School of Medicine, New York, NY 10016, USA; Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, NYU School of Medicine, New York, NY 10016, USA; Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA; Department of Neurology, NYU School of Medicine, New York, NY 10016, USA; Perlmutter Cancer Center, NYU School of Medicine, New York, NY 10016, USA
| | - Agnel Sfeir
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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20
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Lines CL, McGrath MJ, Dorwart T, Conn CS. The integrated stress response in cancer progression: a force for plasticity and resistance. Front Oncol 2023; 13:1206561. [PMID: 37601686 PMCID: PMC10435748 DOI: 10.3389/fonc.2023.1206561] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/07/2023] [Indexed: 08/22/2023] Open
Abstract
During their quest for growth, adaptation, and survival, cancer cells create a favorable environment through the manipulation of normal cellular mechanisms. They increase anabolic processes, including protein synthesis, to facilitate uncontrolled proliferation and deplete the tumor microenvironment of resources. As a dynamic adaptation to the self-imposed oncogenic stress, cancer cells promptly hijack translational control to alter gene expression. Rewiring the cellular proteome shifts the phenotypic balance between growth and adaptation to promote therapeutic resistance and cancer cell survival. The integrated stress response (ISR) is a key translational program activated by oncogenic stress that is utilized to fine-tune protein synthesis and adjust to environmental barriers. Here, we focus on the role of ISR signaling for driving cancer progression. We highlight mechanisms of regulation for distinct mRNA translation downstream of the ISR, expand on oncogenic signaling utilizing the ISR in response to environmental stresses, and pinpoint the impact this has for cancer cell plasticity during resistance to therapy. There is an ongoing need for innovative drug targets in cancer treatment, and modulating ISR activity may provide a unique avenue for clinical benefit.
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Affiliation(s)
| | | | | | - Crystal S. Conn
- Department of Radiation Oncology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
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21
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Choi H, Liao YC, Yoon YJ, Grimm J, Lavis LD, Singer RH, Lippincott-Schwartz J. Lysosomal release of amino acids at ER three-way junctions regulates transmembrane and secretory protein mRNA translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551382. [PMID: 37577585 PMCID: PMC10418176 DOI: 10.1101/2023.08.01.551382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
One-third of the mammalian proteome is comprised of transmembrane and secretory proteins that are synthesized on endoplasmic reticulum (ER). Here, we investigate the spatial distribution and regulation of mRNAs encoding these membrane and secretory proteins (termed "secretome" mRNAs) through live cell, single molecule tracking to directly monitor the position and translation states of secretome mRNAs on ER and their relationship to other organelles. Notably, translation of secretome mRNAs occurred preferentially near lysosomes on ER marked by the ER junction-associated protein, Lunapark. Knockdown of Lunapark reduced the extent of secretome mRNA translation without affecting translation of other mRNAs. Less secretome mRNA translation also occurred when lysosome function was perturbed by raising lysosomal pH or inhibiting lysosomal proteases. Secretome mRNA translation near lysosomes was enhanced during amino acid deprivation. Addition of the integrated stress response inhibitor, ISRIB, reversed the translation inhibition seen in Lunapark knockdown cells, implying an eIF2 dependency. Altogether, these findings uncover a novel coordination between ER and lysosomes, in which local release of amino acids and other factors from ER-associated lysosomes patterns and regulates translation of mRNAs encoding secretory and membrane proteins.
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22
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Batjargal T, Zappa F, Grant RJ, Piscopio RA, Chialastri A, Dey SS, Acosta-Alvear D, Wilson MZ. Optogenetic control of the integrated stress response reveals proportional encoding and the stress memory landscape. Cell Syst 2023; 14:551-562.e5. [PMID: 37473728 DOI: 10.1016/j.cels.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 12/27/2022] [Accepted: 06/09/2023] [Indexed: 07/22/2023]
Abstract
The integrated stress response (ISR) is a conserved signaling network that detects aberrations and computes cellular responses. Dissecting these computations has been difficult because physical and chemical inducers of stress activate multiple parallel pathways. To overcome this challenge, we engineered a photo-switchable control over the ISR sensor kinase PKR (opto-PKR), enabling virtual, on-target activation. Using light to control opto-PKR dynamics, we traced information flow through the transcriptome and for key downstream ISR effectors. Our analyses revealed a biphasic, proportional transcriptional response with two dynamic modes, transient and gradual, that correspond to adaptive and terminal outcomes. We then constructed an ordinary differential equation (ODE) model of the ISR, which demonstrated the dependence of future stress responses on past stress. Finally, we tested our model using high-throughput light-delivery to map the stress memory landscape. Our results demonstrate that cells encode information in stress levels, durations, and the timing between encounters. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Taivan Batjargal
- Biomolecular Science and Engineering Program, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Francesca Zappa
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Ryan J Grant
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Robert A Piscopio
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Alex Chialastri
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Siddharth S Dey
- Center for BioEngineering, University of California Santa Barbara, Santa Barbara, CA, USA; Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA; Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Diego Acosta-Alvear
- Biomolecular Science and Engineering Program, University of California Santa Barbara, Santa Barbara, CA, USA; Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, USA; Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA.
| | - Maxwell Z Wilson
- Center for BioEngineering, University of California Santa Barbara, Santa Barbara, CA, USA; Biomolecular Science and Engineering Program, University of California Santa Barbara, Santa Barbara, CA, USA; Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, USA; Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA.
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Perea V, Baron KR, Dolina V, Aviles G, Rosarda JD, Guo X, Kampmann M, Wiseman RL. Pharmacologic Activation of a Compensatory Integrated Stress Response Kinase Promotes Mitochondrial Remodeling in PERK-deficient Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.11.532186. [PMID: 36945406 PMCID: PMC10029010 DOI: 10.1101/2023.03.11.532186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
The integrated stress response (ISR) comprises the eIF2α kinases PERK, GCN2, HRI, and PKR, which induce translational and transcriptional signaling in response to diverse insults. Deficiencies in PERK signaling lead to mitochondrial dysfunction and contribute to the pathogenesis of numerous diseases. We define the potential for pharmacologic activation of compensatory eIF2α kinases to rescue ISR signaling and promote mitochondrial adaptation in PERK-deficient cells. We show that the HRI activator BtdCPU and GCN2 activator halofuginone promote ISR signaling and rescue ER stress sensitivity in PERK-deficient cells. However, BtdCPU induces mitochondrial depolarization, leading to mitochondrial fragmentation and activation of the OMA1-DELE1-HRI signaling axis. In contrast, halofuginone promotes mitochondrial elongation and adaptive mitochondrial respiration, mimicking regulation induced by PERK. This shows halofuginone can compensate for deficiencies in PERK signaling and promote adaptive mitochondrial remodeling, highlighting the potential for pharmacologic ISR activation to mitigate mitochondrial dysfunction and motivating the pursuit of highly-selective ISR activators.
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Affiliation(s)
- Valerie Perea
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Authors contributed equally
| | - Kelsey R. Baron
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
- Authors contributed equally
| | - Vivian Dolina
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Giovanni Aviles
- Department of Biophysics and Biochemistry and Institute for Neurodegenerative Diseases, UCSF, San Francisco, CA 94158
| | - Jessica D. Rosarda
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Xiaoyan Guo
- Department of Biophysics and Biochemistry and Institute for Neurodegenerative Diseases, UCSF, San Francisco, CA 94158
- Department of Genetics and Genome Sciences, University of Connecticut Health, Farmington, CT 06030
| | - Martin Kampmann
- Department of Biophysics and Biochemistry and Institute for Neurodegenerative Diseases, UCSF, San Francisco, CA 94158
| | - R. Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
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Izumi Y, O'Dell KA, Zorumski CF. The herbicide glyphosate inhibits hippocampal long-term potentiation and learning through activation of pro-inflammatory signaling. RESEARCH SQUARE 2023:rs.3.rs-2883114. [PMID: 37214918 PMCID: PMC10197752 DOI: 10.21203/rs.3.rs-2883114/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Background Glyphosate, a herbicide marketed under the trade name Roundup, is now widely used, in part because genetically modified organism plants that are resistant to this agent have been developed. Environmental or dietary exposure to glyphosate is omnipresent and there are concerns this exposure could impair cognitive function in addition to carcinogenicity. Methods Using hippocampal slices from juvenile male rats, we investigated whether glyphosate alters synaptic transmission and induction of long-term potentiation (LTP), a cellular model of learning and memory. Our hypothesis is that glyphosate alters neuronal function and impairs LTP induction via activation of pro-inflammatory processes, because increases in pro-inflammatory cytokines and neuroinflammation have been reported following glyphosate exposure. LTP was induced by delivery of 100 Hz x 1 sec high frequency stimulation (HFS) of the Schaffer collateral pathway and excitatory synaptic potentials (EPSPs) were monitored 60 min after HFS. Resulsts We first tested effects of Roundup on basal synaptic function and LTP induction. Roundup depressed EPSPs in a dose-dependent manner. Basal synaptic transmission was completely suppressed by 2000 ppm. At concentrations ≤ 20 ppm Roundup did not affect basal transmission, but 4 ppm Roundup administered 30 min before HFS inhibited LTP induction. We also observed that acute administration of 10-100 μM glyphosate inhibits LTP induction. Minocycline, an inhibitor of microglial activation, and TAK-242, an inhibitor of toll-like receptor 4 (TLR4), both overcame the inhibitory effects of 100M glyphosate. Similarly, lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS) overcame the inhibitory effects. In addition, ISRIB (integrated stress response inhibitor) and quercetin, an inhibitor of endoplasmic reticulum stress, allowed LTP induction in the presence of glyphosate. We also observed that in vivo glyphosate injection (16.9 mg/kg i.p.) impaired one-trial inhibitory avoidance learning. This learning deficit was overcome by TAK-242. Conclusion While Roundup inhibits LTP induction, these observations indicate that glyphosate alone, the major ingredient of Roundup, can impair cognitive function through pro-inflammatory signaling in microglia. Manipulation of pro-inflammatory signaling could be a useful strategy to prevent cognitive impairment after exposure to a glyphosate-based herbicide (GBH).
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25
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Gupta M, Walters B, Katsara O, Granados Blanco K, Geter P, Schneider R. eIF2Bδ blocks the integrated stress response and maintains eIF2B activity and cancer metastasis by overexpression in breast cancer stem cells. Proc Natl Acad Sci U S A 2023; 120:e2207898120. [PMID: 37014850 PMCID: PMC10104532 DOI: 10.1073/pnas.2207898120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 03/08/2023] [Indexed: 04/05/2023] Open
Abstract
Breast cancer (BC) metastasis involves cancer stem cells (CSCs) and their regulation by micro-RNAs (miRs), but miR targeting of the translation machinery in CSCs is poorly explored. We therefore screened miR expression levels in a range of BC cell lines, comparing non-CSCs to CSCs, and focused on miRs that target translation and protein synthesis factors. We describe a unique translation regulatory axis enacted by reduced expression of miR-183 in breast CSCs, which we show targets the eIF2Bδ subunit of guanine nucleotide exchange factor eIF2B, a regulator of protein synthesis and the integrated stress response (ISR) pathway. We report that reduced expression of miR-183 greatly increases eIF2Bδ protein levels, preventing strong induction of the ISR and eIF2α phosphorylation, by preferential interaction with P-eIF2α. eIF2Bδ overexpression is essential for BC cell invasion, metastasis, maintenance of metastases, and breast CSC expansion in animal models. Increased expression of eIF2Bδ, a site of action of the drug ISRIB that also prevents ISR signaling, is essential for breast CSC maintenance and metastatic capacity.
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Affiliation(s)
- Malavika Gupta
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY10016
| | - Beth A. Walters
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY10016
| | - Olga Katsara
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY10016
| | - Karol Granados Blanco
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY10016
| | - Phillip A. Geter
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY10016
| | - Robert J. Schneider
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY10016
- New York University Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, NY10016
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26
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Szewczyk B, Günther R, Japtok J, Frech MJ, Naumann M, Lee HO, Hermann A. FUS ALS neurons activate major stress pathways and reduce translation as an early protective mechanism against neurodegeneration. Cell Rep 2023; 42:112025. [PMID: 36696267 DOI: 10.1016/j.celrep.2023.112025] [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: 10/05/2022] [Revised: 11/02/2022] [Accepted: 01/06/2023] [Indexed: 01/26/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder causing progressive loss of motor neurons. Mutations in Fused in sarcoma (FUS) leading to its cytoplasmic mislocalization cause a subset of ALS. Under stress, mutant FUS localizes to stress granules (SGs)-cytoplasmic condensates composed of RNA and various proteins. Aberrant dynamics of SGs is linked to the pathology of ALS. Here, using motor neurons (MNs) derived from human induced pluripotent stem cells, we show that, in mutant FUS, MN dynamics of SGs is disturbed. Additionally, heat-shock response (HSR) and integrated stress response (ISR) involved in the regulation of SGs are upregulated in mutant MNs. HSR activation correlates with the amount of cytoplasmic FUS mislocalization. While inhibition of SG formation, translation, or ISR does not influence survival of FUS ALS neurons, proteotoxicity that cannot be compensated with the activation of stress pathways is the main driver of neurodegeneration in early FUS ALS.
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Affiliation(s)
- Barbara Szewczyk
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - René Günther
- Department of Neurology, Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) Dresden, Dresden, Germany
| | - Julia Japtok
- Department of Neurology, Technische Universität Dresden, Dresden, Germany
| | - Moritz J Frech
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Marcel Naumann
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Hyun O Lee
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Andreas Hermann
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany; Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) Rostock/Greifswald, Rostock, Germany; Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock, Germany.
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27
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Wu T, Yu JC, Suresh A, Gale-Day ZJ, Alteen MG, Woo AS, Millbern Z, Johnson OT, Carroll EC, Partch CL, Fourches D, Vinueza NR, Vocadlo DJ, Gestwicki JE. Conformationally responsive dyes enable protein-adaptive differential scanning fluorimetry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.23.525251. [PMID: 36747624 PMCID: PMC9900766 DOI: 10.1101/2023.01.23.525251] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Flexible in vitro methods alter the course of biological discoveries. Differential Scanning Fluorimetry (DSF) is a particularly versatile technique which reports protein thermal unfolding via fluorogenic dye. However, applications of DSF are limited by widespread protein incompatibilities with the available DSF dyes. Here, we enable DSF applications for 66 of 70 tested proteins (94%) including 10 from the SARS-CoV2 virus using a chemically diverse dye library, Aurora, to identify compatible dye-protein pairs in high throughput. We find that this protein-adaptive DSF platform (paDSF) not only triples the previous protein compatibility, but also fundamentally extends the processes observable by DSF, including interdomain allostery in O-GlcNAc Transferase (OGT). paDSF enables routine measurement of protein stability, dynamics, and ligand binding.
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Affiliation(s)
- Taiasean Wu
- Department of Pharmaceutical Chemistry, University of California San Francisco; San Francisco, CA, 94038, USA
- Institute for Neurodegenerative Diseases, University of California, San Francisco; San Francisco, CA, 94038, USA
| | - Joshua C. Yu
- Department of Pharmaceutical Chemistry, University of California San Francisco; San Francisco, CA, 94038, USA
| | - Arundhati Suresh
- Department of Pharmaceutical Chemistry, University of California San Francisco; San Francisco, CA, 94038, USA
| | - Zachary J. Gale-Day
- Department of Pharmaceutical Chemistry, University of California San Francisco; San Francisco, CA, 94038, USA
| | - Matthew G. Alteen
- Department of Chemistry, Simon Fraser University; Burnaby, BC V5A 1S6, Canada
| | - Amanda S. Woo
- Department of Pharmaceutical Chemistry, University of California San Francisco; San Francisco, CA, 94038, USA
| | - Zoe Millbern
- Department of Textile Engineering, North Carolina State University; Raleigh, NC 27695, USA
| | - Oleta T. Johnson
- Institute for Neurodegenerative Diseases, University of California, San Francisco; San Francisco, CA, 94038, USA
| | - Emma C. Carroll
- Institute for Neurodegenerative Diseases, University of California, San Francisco; San Francisco, CA, 94038, USA
| | - Carrie L. Partch
- Department of Chemistry, University of California, Santa Cruz; Santa Cruz, CA, 95064, USA
| | - Denis Fourches
- Department of Textile Engineering, North Carolina State University; Raleigh, NC 27695, USA
| | - Nelson R. Vinueza
- Department of Textile Engineering, North Carolina State University; Raleigh, NC 27695, USA
| | - David J. Vocadlo
- Department of Chemistry, Simon Fraser University; Burnaby, BC V5A 1S6, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University; Burnaby, BC V5A 1S6, Canada
| | - Jason E. Gestwicki
- Department of Pharmaceutical Chemistry, University of California San Francisco; San Francisco, CA, 94038, USA
- Institute for Neurodegenerative Diseases, University of California, San Francisco; San Francisco, CA, 94038, USA
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Luo X, Li C, Yu X, Kuang G, Wang X, Liang J, Jiang J. The effect of hippocampal NR2B-containing NMDA receptors on chronic cognitive dysfunction in rats with temporal lobe epilepsy. ACTA EPILEPTOLOGICA 2023. [DOI: 10.1186/s42494-022-00111-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Abstract
Background
We have previously reported that hippocampal long-term potentiation (LTP) was suppressed in temporal lobe epilepsy (TLE) rats. The N-methyl-D-aspartic acid receptors containing 2B subunit (NR2B-NMDARs) are indispensable to induce the LTP of hippocampus. However, it is still unknown whether the NR2B-NMDARs are implied with the cognitive dysfunction in TLE rats.
Methods
The TLE model was lithium chloride-pilocarpine (li-pilo) model. Morris water maze test was used to evaluate the cognitive function of epileptic rats. Expression of hippocampal NR2B-NMDAs was evaluated by western blotting. Stereotactic injection of NMDA, an agonist of NR2B-NMDARs, into the hippocampus of TLE rats was used to investigate the role of NR2B-NMDARs on cognitive dysfunction.
Results
Cognitive function TLE rats was significantly reduced compared with controls in the Morris water maze test (P < 0.05). Western blotting data showed the down-expression of hippocampal NR2B-NMDARs and p-NR2B in TLE rats compared with the control (P < 0.05). In addition, hippocampal stereolocalization of NMDA injection improved partially the learning and memory in TLE rats (P < 0.05).
Conclusions
Down-expression and low activity of hippocampal NR2B-NMDARs may be implied with chronic cognitive dysfunction in TLE rats.
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Dudka W, Hoser G, Mondal SS, Turos-Korgul L, Swatler J, Kusio-Kobialka M, Wołczyk M, Klejman A, Brewinska-Olchowik M, Kominek A, Wiech M, Machnicki MM, Seferynska I, Stoklosa T, Piwocka K. Targeting integrated stress response with ISRIB combined with imatinib treatment attenuates RAS/RAF/MAPK and STAT5 signaling and eradicates chronic myeloid leukemia cells. BMC Cancer 2022; 22:1254. [PMID: 36460969 PMCID: PMC9719211 DOI: 10.1186/s12885-022-10289-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 11/07/2022] [Indexed: 12/05/2022] Open
Abstract
The integrated stress response (ISR) facilitates cellular adaptation to unfavorable conditions by reprogramming the cellular response. ISR activation was reported in neurological disorders and solid tumors; however, the function of ISR and its role as a possible therapeutic target in hematological malignancies still remain largely unexplored. Previously, we showed that the ISR is activated in chronic myeloid leukemia (CML) cells and correlates with blastic transformation and tyrosine kinase inhibitor (TKI) resistance. Moreover, the ISR was additionally activated in response to imatinib as a type of protective internal signaling. Here, we show that ISR inhibition combined with imatinib treatment sensitized and more effectively eradicated leukemic cells both in vitro and in vivo compared to treatment with single agents. The combined treatment specifically inhibited the STAT5 and RAS/RAF/MEK/ERK pathways, which are recognized as drivers of resistance. Mechanistically, this drug combination attenuated both interacting signaling networks, leading to BCR-ABL1- and ISR-dependent STAT5 activation. Consequently, leukemia engraftment in patient-derived xenograft mice bearing CD34+ TKI-resistant CML blasts carrying PTPN11 mutation responsible for hyperactivation of the RAS/RAF/MAPK and JAK/STAT5 pathways was decreased upon double treatment. This correlated with the downregulation of genes related to the RAS/RAF/MAPK, JAK/STAT5 and stress response pathways and was associated with lower expression of STAT5-target genes regulating proliferation, viability and the stress response. Collectively, these findings highlight the effect of imatinib plus ISRIB in the eradication of leukemic cells resistant to TKIs and suggest potential clinical benefits for leukemia patients with TKI resistance related to RAS/RAF/MAPK or STAT5 signaling. We propose that personalized treatment based on the genetic selection of patients carrying mutations that cause overactivation of the targeted pathways and therefore make their sensitivity to such treatment probable should be considered as a possible future direction in leukemia treatment.
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Affiliation(s)
- Wioleta Dudka
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Grazyna Hoser
- Center of Postgraduate Medical Education, Laboratory of Flow Cytometry, Warsaw, Poland
| | - Shamba S. Mondal
- grid.419305.a0000 0001 1943 2944Laboratory of Bioinformatics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Laura Turos-Korgul
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Julian Swatler
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Monika Kusio-Kobialka
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Magdalena Wołczyk
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Agata Klejman
- grid.419305.a0000 0001 1943 2944Laboratory of Animal Models, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Marta Brewinska-Olchowik
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Agata Kominek
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Milena Wiech
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Marcin M. Machnicki
- grid.13339.3b0000000113287408Department of Tumor Biology and Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Ilona Seferynska
- grid.419032.d0000 0001 1339 8589Department of Hematology, Institute of Hematology and Blood Transfusion, Warsaw, Poland
| | - Tomasz Stoklosa
- grid.13339.3b0000000113287408Department of Tumor Biology and Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Piwocka
- grid.419305.a0000 0001 1943 2944Laboratory of Cytometry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
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Kamble VS, Pachpor TA, Khandagale SB, Wagh VV, Khare SP. Translation initiation and dysregulation of initiation factors in rare diseases. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Bruno T, Corleone G, Catena V, Cortile C, De Nicola F, Fabretti F, Gumenyuk S, Pisani F, Mengarelli A, Passananti C, Fanciulli M. AATF/Che-1 localizes to paraspeckles and suppresses R-loops accumulation and interferon activation in Multiple Myeloma. EMBO J 2022; 41:e109711. [PMID: 35929179 PMCID: PMC9670196 DOI: 10.15252/embj.2021109711] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 07/06/2022] [Accepted: 07/14/2022] [Indexed: 01/13/2023] Open
Abstract
Several kinds of stress promote the formation of three-stranded RNA:DNA hybrids called R-loops. Insufficient clearance of these structures promotes genomic instability and DNA damage, which ultimately contribute to the establishment of cancer phenotypes. Paraspeckle assemblies participate in R-loop resolution and preserve genome stability, however, the main determinants of this mechanism are still unknown. This study finds that in Multiple Myeloma (MM), AATF/Che-1 (Che-1), an RNA-binding protein fundamental to transcription regulation, interacts with paraspeckles via the lncRNA NEAT1_2 (NEAT1) and directly localizes on R-loops. We systematically show that depletion of Che-1 produces a marked accumulation of RNA:DNA hybrids. We provide evidence that such failure to resolve R-loops causes sustained activation of a systemic inflammatory response characterized by an interferon (IFN) gene expression signature. Furthermore, elevated levels of R-loops and of mRNA for paraspeckle genes in patient cells are linearly correlated with Multiple Myeloma progression. Moreover, increased interferon gene expression signature in patients is associated with markedly poor prognosis. Taken together, our study indicates that Che-1/NEAT1 cooperation prevents excessive inflammatory signaling in Multiple Myeloma by facilitating the clearance of R-loops. Further studies on different cancer types are needed to test if this mechanism is ubiquitously conserved and fundamental for cell homeostasis.
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Affiliation(s)
- Tiziana Bruno
- SAFU Laboratory, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research AreaIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Giacomo Corleone
- SAFU Laboratory, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research AreaIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Valeria Catena
- SAFU Laboratory, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research AreaIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Clelia Cortile
- SAFU Laboratory, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research AreaIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Francesca De Nicola
- SAFU Laboratory, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research AreaIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Francesca Fabretti
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital of CologneUniversity of CologneCologneGermany,Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Svitlana Gumenyuk
- Hematology UnitIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Francesco Pisani
- Hematology UnitIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Andrea Mengarelli
- Hematology UnitIRCCS Regina Elena National Cancer InstituteRomeItaly
| | - Claudio Passananti
- Department of Molecular Medicine, CNR‐Institute of Molecular Biology and PathologySapienza University of RomeRomeItaly
| | - Maurizio Fanciulli
- SAFU Laboratory, Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research AreaIRCCS Regina Elena National Cancer InstituteRomeItaly
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Krokowski D, Jobava R, Szkop KJ, Chen CW, Fu X, Venus S, Guan BJ, Wu J, Gao Z, Banaszuk W, Tchorzewski M, Mu T, Ropelewski P, Merrick WC, Mao Y, Sevval AI, Miranda H, Qian SB, Manifava M, Ktistakis NT, Vourekas A, Jankowsky E, Topisirovic I, Larsson O, Hatzoglou M. Stress-induced perturbations in intracellular amino acids reprogram mRNA translation in osmoadaptation independently of the ISR. Cell Rep 2022; 40:111092. [PMID: 35858571 PMCID: PMC9491157 DOI: 10.1016/j.celrep.2022.111092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/26/2022] [Accepted: 06/22/2022] [Indexed: 12/23/2022] Open
Abstract
The integrated stress response (ISR) plays a pivotal role in adaptation of translation machinery to cellular stress. Here, we demonstrate an ISR-independent osmoadaptation mechanism involving reprogramming of translation via coordinated but independent actions of mTOR and plasma membrane amino acid transporter SNAT2. This biphasic response entails reduced global protein synthesis and mTOR signaling followed by translation of SNAT2. Induction of SNAT2 leads to accumulation of amino acids and reactivation of mTOR and global protein synthesis, paralleled by partial reversal of the early-phase, stress-induced translatome. We propose SNAT2 functions as a molecular switch between inhibition of protein synthesis and establishment of an osmoadaptive translation program involving the formation of cytoplasmic condensates of SNAT2-regulated RNA-binding proteins DDX3X and FUS. In summary, we define key roles of SNAT2 in osmotolerance.
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Affiliation(s)
- Dawid Krokowski
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland.
| | - Raul Jobava
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Krzysztof J Szkop
- Department of Oncology-Pathology, Science for Life Laboratories, Karolinska Institute, Stockholm, Sweden
| | - Chien-Wen Chen
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Xu Fu
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Bo-Jhih Guan
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jing Wu
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Zhaofeng Gao
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Wioleta Banaszuk
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Marek Tchorzewski
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland; EcoTech-Complex Centre, Maria Curie-Skłodowska University, Lublin, Poland
| | - Tingwei Mu
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Phil Ropelewski
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - William C Merrick
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Yuanhui Mao
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Aksoylu Inci Sevval
- Department of Oncology-Pathology, Science for Life Laboratories, Karolinska Institute, Stockholm, Sweden
| | - Helen Miranda
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | | | | | - Anastasios Vourekas
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Eckhard Jankowsky
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Ivan Topisirovic
- The Lady Davis Institute, Jewish General Hospital, Montréal, QC, Canada; Gerald Bronfman Department of Oncology, McGill University, Montréal, QC, Canada; Department of Biochemistry and Division of Experimental Medicine, McGill University, Montréal, QC, Canada.
| | - Ola Larsson
- Department of Oncology-Pathology, Science for Life Laboratories, Karolinska Institute, Stockholm, Sweden.
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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The role of eIF2 phosphorylation in cell and organismal physiology: new roles for well-known actors. Biochem J 2022; 479:1059-1082. [PMID: 35604373 DOI: 10.1042/bcj20220068] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 02/06/2023]
Abstract
Control of protein synthesis (mRNA translation) plays key roles in shaping the proteome and in many physiological, including homeostatic, responses. One long-known translational control mechanism involves phosphorylation of initiation factor, eIF2, which is catalysed by any one of four protein kinases, which are generally activated in response to stresses. They form a key arm of the integrated stress response (ISR). Phosphorylated eIF2 inhibits eIF2B (the protein that promotes exchange of eIF2-bound GDP for GTP) and thus impairs general protein synthesis. However, this mechanism actually promotes translation of certain mRNAs by virtue of specific features they possess. Recent work has uncovered many previously unknown features of this regulatory system. Several studies have yielded crucial insights into the structure and control of eIF2, including that eIF2B is regulated by several metabolites. Recent studies also reveal that control of eIF2 and the ISR helps determine organismal lifespan and surprising roles in sensing mitochondrial stresses and in controlling the mammalian target of rapamycin (mTOR). The latter effect involves an unexpected role for one of the eIF2 kinases, HRI. Phosphoproteomic analysis identified new substrates for another eIF2 kinase, Gcn2, which senses the availability of amino acids. Several genetic disorders arise from mutations in genes for eIF2α kinases or eIF2B (i.e. vanishing white matter disease, VWM and microcephaly, epileptic seizures, microcephaly, hypogenitalism, diabetes and obesity, MEHMO). Furthermore, the eIF2-mediated ISR plays roles in cognitive decline associated with Alzheimer's disease. New findings suggest potential therapeutic value in interfering with the ISR in certain settings, including VWM, for example by using compounds that promote eIF2B activity.
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Regulation and function of elF2B in neurological and metabolic disorders. Biosci Rep 2022; 42:231311. [PMID: 35579296 PMCID: PMC9208314 DOI: 10.1042/bsr20211699] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/28/2022] [Accepted: 05/12/2022] [Indexed: 11/27/2022] Open
Abstract
Eukaryotic initiation factor 2B, eIF2B is a guanine nucleotide exchange, factor with a central role in coordinating the initiation of translation. During stress and disease, the activity of eIF2B is inhibited via the phosphorylation of its substrate eIF2 (p-eIF2α). A number of different kinases respond to various stresses leading to the phosphorylation of the alpha subunit of eIF2, and collectively this regulation is known as the integrated stress response, ISR. This targeting of eIF2B allows the cell to regulate protein synthesis and reprogramme gene expression to restore homeostasis. Advances within structural biology have furthered our understanding of how eIF2B interacts with eIF2 in both the productive GEF active form and the non-productive eIF2α phosphorylated form. Here, current knowledge of the role of eIF2B in the ISR is discussed within the context of normal and disease states focusing particularly on diseases such as vanishing white matter disease (VWMD) and permanent neonatal diabetes mellitus (PNDM), which are directly linked to mutations in eIF2B. The role of eIF2B in synaptic plasticity and memory formation is also discussed. In addition, the cellular localisation of eIF2B is reviewed and considered along with the role of additional in vivo eIF2B binding factors and protein modifications that may play a role in modulating eIF2B activity during health and disease.
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Boone M, Wang L, Lawrence RE, Frost A, Walter P, Schoof M. A point mutation in the nucleotide exchange factor eIF2B constitutively activates the integrated stress response by allosteric modulation. eLife 2022; 11:e76171. [PMID: 35416150 PMCID: PMC9132573 DOI: 10.7554/elife.76171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
In eukaryotic cells, stressors reprogram the cellular proteome by activating the integrated stress response (ISR). In its canonical form, stress-sensing kinases phosphorylate the eukaryotic translation initiation factor eIF2 (eIF2-P), which ultimately leads to reduced levels of ternary complex required for initiation of mRNA translation. Previously we showed that translational control is primarily exerted through a conformational switch in eIF2's nucleotide exchange factor, eIF2B, which shifts from its active A-State conformation to its inhibited I-State conformation upon eIF2-P binding, resulting in reduced nucleotide exchange on eIF2 (Schoof et al. 2021). Here, we show functionally and structurally how a single histidine to aspartate point mutation in eIF2B's β subunit (H160D) mimics the effects of eIF2-P binding by promoting an I-State like conformation, resulting in eIF2-P independent activation of the ISR. These findings corroborate our previously proposed A/I-State model of allosteric ISR regulation.
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Affiliation(s)
- Morgane Boone
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
| | - Lan Wang
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
| | - Rosalie E Lawrence
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
| | - Peter Walter
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
| | - Michael Schoof
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
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36
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The integrated stress response in ischemic diseases. Cell Death Differ 2022; 29:750-757. [PMID: 34743204 PMCID: PMC8990009 DOI: 10.1038/s41418-021-00889-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 12/20/2022] Open
Abstract
Ischemic disease is among the deadliest and most disabling illnesses. Prominent examples include myocardial infarction and stroke. Most, if not all, underlying pathological changes, including oxidative stress, inflammation, and nutrient deprivation, are potent inducers of the integrated stress response (ISR). Four upstream kinases are involved in ISR signaling that sense a myriad of input stress signals and converge on the phosphorylation of serine 51 of eukaryotic translation initiation factor 2α (eIF2α). As a result, translation initiation is halted, creating a window of opportunity for the cell to repair itself and restore homeostasis. A growing number of studies show strong induction of the ISR in ischemic disease. Genetic and pharmacological evidence suggests that the ISR plays critical roles in disease initiation and progression. Here, we review the basic regulation of the ISR, particularly in response to ischemia, and summarize recent findings relevant to the actions of the ISR in ischemic disease. We then discuss therapeutic opportunities by modulating the ISR to treat ischemic heart disease, brain ischemia, ischemic liver disease, and ischemic kidney disease. Finally, we propose that the ISR represents a promising therapeutic target for alleviating symptoms of ischemic disease and improving clinical outcomes.
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37
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GCN2: roles in tumour development and progression. Biochem Soc Trans 2022; 50:737-745. [PMID: 35311890 PMCID: PMC9162460 DOI: 10.1042/bst20211252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/01/2022] [Accepted: 03/07/2022] [Indexed: 12/12/2022]
Abstract
GCN2 (general control nonderepessible 2) is an eIF2α kinase responsible for entirely rewiring the metabolism of cells when they are put under amino acid starvation stress. Recently, there has been renewed interest in GCN2 as a potential oncotarget, with several studies reporting the development of small molecule inhibitors. The foundation of this work is built upon biochemical and cellular data which suggest GCN2 may be aberrantly overexpressed and is responsible for keeping cells on ‘life-support’ while tumours undergo significant nutritional stress during tumorigenesis, allowing cancer stem cells to develop chemotherapeutic resistance. However, most studies which have investigated the role of GCN2 in cancer have been conducted in various cancer model systems, often under a specific set of stresses, mutational backgrounds and drug cocktails. This review aims to comprehensively summarise the biochemical, molecular and cellular literature associated with GCN2 and its role in various cancers and determine whether a consensus can be developed to discern under which circumstances we may wish to target GCN2.
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38
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Inhibition of the ISR abrogates mGluR5-dependent long-term depression and spatial memory deficits in a rat model of Alzheimer's disease. Transl Psychiatry 2022; 12:96. [PMID: 35260557 PMCID: PMC8904583 DOI: 10.1038/s41398-022-01862-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/18/2022] [Accepted: 02/18/2022] [Indexed: 12/13/2022] Open
Abstract
Soluble amyloid-β-protein (Aβ) oligomers, a major hallmark of AD, trigger the integrated stress response (ISR) via multiple pathologies including neuronal hyperactivation, microvascular hypoxia, and neuroinflammation. Increasing eIF2α phosphorylation, the core event of ISR, facilitates metabotropic glutamate receptor (mGluR)-dependent long-term depression (LTD), and suppressing its phosphorylation has the opposite effect. Having found the facilitation of mGluR5-LTD by Aβ in live rats, we wondered if suppressing eIF2α phosphorylation cascade would protect against the synaptic plasticity and cognitive disrupting effects of Aβ. We demonstrate here that the facilitation of mGluR5-LTD in a delayed rat model by single i.c.v. injection of synthetic Aβ1-42. Systemic administration of the small-molecule inhibitor of the ISR called ISRIB (trans-isomer) prevents Aβ-facilitated LTD and abrogates spatial learning and memory deficits in the hippocampus in exogenous synthetic Aβ-injected rats. Moreover, ex vivo evidence indicates that ISRIB normalizes protein synthesis in the hippocampus. Targeting the ISR by suppressing the eIF2α phosphorylation cascade with the eIF2B activator ISRIB may provide protective effects against the synaptic and cognitive disruptive effects of Aβ which likely mediate the early stage of sporadic AD.
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39
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Cao S, Kang S, Mao H, Yao J, Gu L, Zheng N. Defining molecular glues with a dual-nanobody cannabidiol sensor. Nat Commun 2022; 13:815. [PMID: 35145136 PMCID: PMC8831599 DOI: 10.1038/s41467-022-28507-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/27/2022] [Indexed: 12/14/2022] Open
Abstract
"Molecular glue" (MG) is a term coined to describe the mechanism of action of the plant hormone auxin and subsequently used to characterize synthetic small molecule protein degraders exemplified by immune-modulatory imide drugs (IMiDs). Prospective development of MGs, however, has been hampered by its elusive definition and thermodynamic characteristics. Here, we report the crystal structure of a dual-nanobody cannabidiol-sensing system, in which the ligand promotes protein-protein interaction in a manner analogous to auxin. Through quantitative analyses, we draw close parallels among the dual-nanobody cannabidiol sensor, the auxin perception complex, and the IMiDs-bound CRL4CRBN E3, which can bind and ubiquitinate "neo-substrates". All three systems, including the recruitment of IKZF1 and CK1α to CRBN, are characterized by the lack of ligand binding activity in at least one protein partner and an under-appreciated preexisting low micromolar affinity between the two proteinaceous subunits that is enhanced by the ligand to reach the nanomolar range. These two unifying features define MGs as a special class of proximity inducers distinct from bifunctional compounds and can be used as criteria to guide target selection for future rational discovery of MGs.
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Affiliation(s)
- Shiyun Cao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Shoukai Kang
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Haibin Mao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Jiayu Yao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Liangcai Gu
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Ning Zheng
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.
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40
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Korneeva NL. Integrated Stress Response in Neuronal Pathology and in Health. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:S111-S127. [PMID: 35501991 DOI: 10.1134/s0006297922140103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 06/14/2023]
Abstract
Neurodegeneration involves progressive pathological loss of a specific population of neurons, glial activation, and dysfunction of myelinating oligodendrocytes leading to cognitive impairment and altered movement, breathing, and senses. Neuronal degeneration is a hallmark of aging, stroke, drug abuse, toxic chemical exposure, viral infection, chronic inflammation, and a variety of neurological diseases. Accumulation of intra- and extracellular protein aggregates is a common characteristic of cell pathologies. Excessive production of reactive oxygen species and nitric oxide, induction of endoplasmic reticulum stress, and accumulation of misfolded protein aggregates have been shown to trigger a defensive mechanism called integrated stress response (ISR). Activation of ISR is important for synaptic plasticity in learning and memory formation. However, sustaining of ISR may lead to the development of neuronal pathologies and altered patterns in behavior and perception.
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Affiliation(s)
- Nadejda L Korneeva
- Louisiana State University Health Science Center, Shreveport, LA 71103, USA.
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41
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Sekine Y, Ron D, Zyryanova AF. Fluorescence Intensity-Based eIF2B's Guanine Nucleotide-Exchange Factor Activity Assay. Methods Mol Biol 2022; 2428:187-196. [PMID: 35171481 DOI: 10.1007/978-1-0716-1975-9_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Guanine nucleotide-exchange factors (GEFs) activate the function of guanine nucleotide-binding proteins (G-proteins) by promoting the exchange of GDP for GTP on the latter. Here, we describe a protocol for in vitro measurements of the GEF activity of eukaryotic translation initiation factor 2B, eIF2B, toward its substrate eIF2. This protocol provides a relatively simple method for determining the eIF2B's GEF activity in crude cell extracts. The eIF2 heterotrimeric substrate, with phosphorylated or unphosphorylated eIF2α, is prepared by immunoprecipitation, following subsequent loading of a fluorescent BODIPY-FL dye-attached GDP. The exchange of the bound fluorescent GDP molecule for an unlabeled one on eIF2 promoted by eIF2B is monitored kinetically using a fluorescence microplate reader.
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Affiliation(s)
- Yusuke Sekine
- Division of Endocrinology and Metabolism, Department of Medicine, Aging Institute, University of Pittsburgh, Pittsburgh, PA, USA.
| | - David Ron
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, UK
| | - Alisa F Zyryanova
- Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge, UK
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42
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Schoof M, Wang L, Cogan JZ, Lawrence RE, Boone M, Wuerth JD, Frost A, Walter P. Viral evasion of the integrated stress response through antagonism of eIF2-P binding to eIF2B. Nat Commun 2021; 12:7103. [PMID: 34876554 PMCID: PMC8651678 DOI: 10.1038/s41467-021-26164-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/17/2021] [Indexed: 01/07/2023] Open
Abstract
Viral infection triggers activation of the integrated stress response (ISR). In response to viral double-stranded RNA (dsRNA), RNA-activated protein kinase (PKR) phosphorylates the translation initiation factor eIF2, converting it from a translation initiator into a potent translation inhibitor and this restricts the synthesis of viral proteins. Phosphorylated eIF2 (eIF2-P) inhibits translation by binding to eIF2's dedicated, heterodecameric nucleotide exchange factor eIF2B and conformationally inactivating it. We show that the NSs protein of Sandfly Fever Sicilian virus (SFSV) allows the virus to evade the ISR. Mechanistically, NSs tightly binds to eIF2B (KD = 30 nM), blocks eIF2-P binding, and rescues eIF2B GEF activity. Cryo-EM structures demonstrate that SFSV NSs and eIF2-P directly compete, with the primary NSs contacts to eIF2Bα mediated by five 'aromatic fingers'. NSs binding preserves eIF2B activity by maintaining eIF2B's conformation in its active A-State.
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Affiliation(s)
- Michael Schoof
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Lan Wang
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - J Zachery Cogan
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Rosalie E Lawrence
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Morgane Boone
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | | | - Adam Frost
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Peter Walter
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA.
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA.
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43
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Lant JT, Kiri R, Duennwald ML, O'Donoghue P. Formation and persistence of polyglutamine aggregates in mistranslating cells. Nucleic Acids Res 2021; 49:11883-11899. [PMID: 34718744 PMCID: PMC8599886 DOI: 10.1093/nar/gkab898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/03/2021] [Accepted: 09/20/2021] [Indexed: 12/17/2022] Open
Abstract
In neurodegenerative diseases, including pathologies with well-known causative alleles, genetic factors that modify severity or age of onset are not entirely understood. We recently documented the unexpected prevalence of transfer RNA (tRNA) mutants in the human population, including variants that cause amino acid mis-incorporation. We hypothesized that a mistranslating tRNA will exacerbate toxicity and modify the molecular pathology of Huntington's disease-causing alleles. We characterized a tRNAPro mutant that mistranslates proline codons with alanine, and tRNASer mutants, including a tRNASerAGA G35A variant with a phenylalanine anticodon (tRNASerAAA) found in ∼2% of the population. The tRNAPro mutant caused synthetic toxicity with a deleterious huntingtin poly-glutamine (polyQ) allele in neuronal cells. The tRNASerAAA variant showed synthetic toxicity with proteasome inhibition but did not enhance toxicity of the huntingtin allele. Cells mistranslating phenylalanine or proline codons with serine had significantly reduced rates of protein synthesis. Mistranslating cells were slow but effective in forming insoluble polyQ aggregates, defective in protein and aggregate degradation, and resistant to the neuroprotective integrated stress response inhibitor (ISRIB). Our findings identify mistranslating tRNA variants as genetic factors that slow protein aggregation kinetics, inhibit aggregate clearance, and increase drug resistance in cellular models of neurodegenerative disease.
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Affiliation(s)
- Jeremy T Lant
- Department of Biochemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Rashmi Kiri
- Department of Biochemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Martin L Duennwald
- Department of Anatomy & Cell Biology, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
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44
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Zhang G, Wang X, Li C, Li Q, An YA, Luo X, Deng Y, Gillette TG, Scherer PE, Wang ZV. Integrated Stress Response Couples Mitochondrial Protein Translation With Oxidative Stress Control. Circulation 2021; 144:1500-1515. [PMID: 34583519 PMCID: PMC8563444 DOI: 10.1161/circulationaha.120.053125] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND The integrated stress response (ISR) is an evolutionarily conserved process to cope with intracellular and extracellular disturbances. Myocardial infarction is a leading cause of death worldwide. Coronary artery reperfusion, the most effective means to mitigate cardiac damage of myocardial infarction, causes additional reperfusion injury. This study aimed to investigate the role of the ISR in myocardial ischemia/reperfusion (I/R). METHODS Cardiac-specific gain- and loss-of-function approaches for the ISR were used in vivo. Myocardial I/R was achieved by ligation of the cardiac left anterior descending artery for 45 minutes followed by reperfusion for different times. Cardiac function was assessed by echocardiography. Cultured H9c2 cells, primary rat cardiomyocytes, and mouse embryonic fibroblasts were used to dissect underlying molecular mechanisms. Tandem mass tag labeling and mass spectrometry was conducted to identify protein targets of the ISR. Pharmacologic means were tested to manipulate the ISR for therapeutic exploration. RESULTS We show that the PERK (PKR-like endoplasmic reticulum resident kinase)/eIF2α (α subunit of eukaryotic initiation factor 2) axis of the ISR is strongly induced by I/R in cardiomyocytes in vitro and in vivo. We further reveal a physiologic role of PERK/eIF2α signaling by showing that acute activation of PERK in the heart confers robust cardioprotection against reperfusion injury. In contrast, cardiac-specific deletion of PERK aggravates cardiac responses to reperfusion. Mechanistically, the ISR directly targets mitochondrial complexes through translational suppression. We identify NDUFAF2 (NADH:ubiquinone oxidoreductase complex assembly factor 2), an assembly factor of mitochondrial complex I, as a selective target of PERK. Overexpression of PERK suppresses the protein expression of NDUFAF2 and PERK inhibition causes an increase of NDUFAF2. Silencing of NDUFAF2 significantly rescues cardiac cell survival from PERK knockdown under I/R. We show that activation of PERK/eIF2α signaling reduces mitochondrial complex-derived reactive oxygen species and improves cardiac cell survival in response to I/R. Moreover, pharmacologic stimulation of the ISR protects the heart against reperfusion damage, even after the restoration of occluded coronary artery, highlighting clinical relevance for myocardial infarction treatment. CONCLUSIONS These results suggest that the ISR improves cell survival and mitigates reperfusion damage by selectively suppressing mitochondrial protein synthesis and reducing oxidative stress in the heart.
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Affiliation(s)
- Guangyu Zhang
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Xiaoding Wang
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Chao Li
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Qinfeng Li
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Yu A An
- Touchstone Diabetes Center (Y.A.A., Y.D., P.E.S.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Xiang Luo
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Yingfeng Deng
- Touchstone Diabetes Center (Y.A.A., Y.D., P.E.S.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Thomas G Gillette
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Philipp E Scherer
- Touchstone Diabetes Center (Y.A.A., Y.D., P.E.S.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
| | - Zhao V Wang
- Division of Cardiology (G.Z., X.W., C.L., Q.L., X.L., T.G.G., Z.V.W.), Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
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Pharmacological targeting of endoplasmic reticulum stress in disease. Nat Rev Drug Discov 2021; 21:115-140. [PMID: 34702991 DOI: 10.1038/s41573-021-00320-3] [Citation(s) in RCA: 183] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2021] [Indexed: 02/08/2023]
Abstract
The accumulation of misfolded proteins in the endoplasmic reticulum (ER) leads to ER stress, resulting in activation of the unfolded protein response (UPR) that aims to restore protein homeostasis. However, the UPR also plays an important pathological role in many diseases, including metabolic disorders, cancer and neurological disorders. Over the last decade, significant effort has been invested in targeting signalling proteins involved in the UPR and an array of drug-like molecules is now available. However, these molecules have limitations, the understanding of which is crucial for their development into therapies. Here, we critically review the existing ER stress and UPR-directed drug-like molecules, highlighting both their value and their limitations.
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Chang L, Liu X, Chen J, Liu H, Wang G, Wang G, Liao X, Shen X. Attenuation of Activated eIF2α Signaling by ISRIB Treatment After Spinal Cord Injury Improves Locomotor Function. J Mol Neurosci 2021; 72:585-597. [PMID: 34647267 PMCID: PMC8921087 DOI: 10.1007/s12031-021-01920-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022]
Abstract
Following spinal cord injury (SCI), multiple signaling cascades are activated instantaneously in the injured segments of the spinal cord to create a complex and pathogenic microenvironment, making it difficult to treat SCI. Nevertheless, the significance of the integrated stress response (ISR) to the series of physiological and pathological changes that occur after SCI remains unclear. Through western blotting (WB), we determined that the autophosphorylation of stress receptors (GCN2, PERK, PKR, and HRI) was enhanced after SCI, leading to increased phosphorylation of eIF2α at Ser51. Strikingly, we found that eIF2α was highly phosphorylated at 1 day post injury (dpi) and that this hypophosphorylation was maintained thereafter in the spinal cord, especially in neurons, which suggests that intervening with eIF2α phosphorylation may be a treatment strategy for SCI. Therefore, we employed the small molecule ISRIB, which inhibits eIF2α phosphorylation when the ISR is activated at moderate or low levels but not when the ISR is highly activated. Daily intraperitoneal injection of ISRIB significantly inhibited ISR signaling after SCI, reduced the cytosolic localization of RNA-binding proteins, and decreased neuronal apoptosis. Histological and functional experiments further demonstrated that treatment with ISRIB after SCI effectively curbed morphological deterioration and promoted the recovery of locomotor function. In summary, the ISR plays an important role in SCI, and ISRIB is a promising drug for the treatment of SCI.
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Affiliation(s)
- Lei Chang
- Department of Spine Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), No.61, West Jiefang Road, Changsha, 410005, China
| | - Xiangyang Liu
- Department of Spine Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), No.61, West Jiefang Road, Changsha, 410005, China
| | - Jing Chen
- Department of Endocrinology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), Changsha, China
| | - Hongzhe Liu
- Department of Spine Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), No.61, West Jiefang Road, Changsha, 410005, China
| | - Guoping Wang
- Department of Spine Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), No.61, West Jiefang Road, Changsha, 410005, China
| | - Guohua Wang
- Department of Spine Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), No.61, West Jiefang Road, Changsha, 410005, China
| | - Xiaoyun Liao
- Department of Anesthesiology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), Changsha, China
| | - Xiongjie Shen
- Department of Spine Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University), No.61, West Jiefang Road, Changsha, 410005, China.
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Zhang T, Wu Y, Hu Z, Xing W, Kun LV, Wang D, Hu N. Small-Molecule Integrated Stress Response Inhibitor Reduces Susceptibility to Postinfarct Atrial Fibrillation in Rats via the Inhibition of Integrated Stress Responses. J Pharmacol Exp Ther 2021; 378:197-206. [PMID: 34215702 DOI: 10.1124/jpet.121.000491] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/23/2021] [Indexed: 11/22/2022] Open
Abstract
Phosphorylation of the eukaryotic translation initiation factor 2 α-subunit, which subsequently upregulates activating transcription factor 4 (ATF4), is the core event in the integrated stress response (ISR) pathway. Previous studies indicate phosphorylation of eukaryotic translation initiation factor 2 ɑ-subunit in atrial tissue in response to atrial fibrillation (AF). This study investigated the role of ISR pathway in experimental AF by using a small-molecule ISR inhibitor (ISRIB). Accordingly, rats were subjected to coronary artery occlusion to induce myocardial infarction (MI), or sham operation, and received either trans-ISRIB (2 mg/kg/d, i.p.) or vehicle for seven days. Thereafter, animals were subjected to the AF inducibility test by transesophageal rapid burst pacing followed by procurement of left atrium (LA) for assessment of atrial fibrosis, inflammatory indices, autophagy-related proteins, ISR activation, ion channel, and connexin 43 expression. Results showed a significant increase in the AF vulnerability and the activation of ISR in LA as evidenced by enhanced eukaryotic translation initiation factor 2 ɑ-subunit phosphorylation. ISRIB treatment suppressed upregulation of ATF4, fibrosis as indexed by determination of α-smooth muscle actin and collagen levels, inflammatory macrophage infiltration (i.e., CD68 and inducible nitric oxide synthase/CD68-positive macrophage), and autophagy as determined by expression of light chain 3. Further, ISRIB treatment reversed the expression of relevant ion channel (i.e., the voltage-gated sodium channel 1.5 , L-type voltage-dependent calcium channel 1.2, and voltage-activated A-type potassium ion channel 4.3) and connexin 43 remodeling. Collectively, the results suggest that the ISR is a key pathway in pathogenesis of AF, post-MI, and represents a novel target for treatment of AF. SIGNIFICANCE STATEMENT: The activation of integrated stress response (ISR) pathway as evidenced by enhanced eukaryotic translation initiation factor 2 ɑ-subunit phosphorylation in left atrium plays a key role in atrial fibrillation (AF). ISR inhibitor (ISRIB) reduces AF occurrence and atrial proarrhythmogenic substrate. The beneficial action of ISRIB may be mediated by suppressing ISR pathway-related cardiac fibrosis, inflammatory macrophage infiltration, autophagy, and restoring the expression of ion channel and connexin 43. This study suggests a key dysfunctional role for ISR in pathogenesis of AF with implications for novel treatment.
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Affiliation(s)
- Ting Zhang
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
| | - Yong Wu
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
| | - Zhengtao Hu
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
| | - Wen Xing
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
| | - L V Kun
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
| | - Deguo Wang
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
| | - Nengwei Hu
- Department of Gerontology (T.Z., Y.W., Z.H., W.X., D.W., N.H.) and Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution (W.X., K.L., D.W., N.H.), First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, China; Department of Psychology, Wannan Medical College, Wuhu, Anhui, China (T.Z.); and Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland (N.H.)
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48
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Derisbourg MJ, Hartman MD, Denzel MS. Perspective: Modulating the integrated stress response to slow aging and ameliorate age-related pathology. NATURE AGING 2021; 1:760-768. [PMID: 35146440 PMCID: PMC7612338 DOI: 10.1038/s43587-021-00112-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022]
Abstract
Healthy aging requires the coordination of numerous stress signaling pathways that converge on the protein homeostasis network. The Integrated Stress Response (ISR) is activated by diverse stimuli, leading to phosphorylation of the eukaryotic translation initiation factor elF2 in its α-subunit. Under replete conditions, elF2 orchestrates 5' cap-dependent mRNA translation and is thus responsible for general protein synthesis. elF2α phosphorylation, the key event of the ISR, reduces global mRNA translation while enhancing the expression of a signature set of stress response genes. Despite the critical role of protein quality control in healthy aging and in numerous longevity pathways, the role of the ISR in longevity remains largely unexplored. ISR activity increases with age, suggesting a potential link with the aging process. Although decreased protein biosynthesis, which occurs during ISR activation, have been linked to lifespan extension, recent data show that lifespan is limited by the ISR as its inhibition extends survival in nematodes and enhances cognitive function in aged mice. Here we survey how aging affects the ISR, the role of the ISR in modulating aging, and pharmacological interventions to tune the ISR. Finally, we will explore the ISR as a plausible target for clinical interventions in aging and age-related disease.
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Affiliation(s)
| | | | - Martin S Denzel
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- CECAD - Cluster of Excellence, University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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49
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English AM, Green KM, Moon SL. A (dis)integrated stress response: Genetic diseases of eIF2α regulators. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1689. [PMID: 34463036 DOI: 10.1002/wrna.1689] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/28/2023]
Abstract
The integrated stress response (ISR) is a conserved mechanism by which eukaryotic cells remodel gene expression to adapt to intrinsic and extrinsic stressors rapidly and reversibly. The ISR is initiated when stress-activated protein kinases phosphorylate the major translation initiation factor eukaryotic translation initiation factor 2ɑ (eIF2ɑ), which globally suppresses translation initiation activity and permits the selective translation of stress-induced genes including important transcription factors such as activating transcription factor 4 (ATF4). Translationally repressed messenger RNAs (mRNAs) and noncoding RNAs assemble into cytoplasmic RNA-protein granules and polyadenylated RNAs are concomitantly stabilized. Thus, regulated changes in mRNA translation, stability, and localization to RNA-protein granules contribute to the reprogramming of gene expression that defines the ISR. We discuss fundamental mechanisms of RNA regulation during the ISR and provide an overview of a growing class of genetic disorders associated with mutant alleles of key translation factors in the ISR pathway. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease Translation > Translation Regulation RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Alyssa M English
- Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Katelyn M Green
- Department of Chemistry, Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Stephanie L Moon
- Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
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50
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Hall BS, Dos Santos SJ, Hsieh LTH, Manifava M, Ruf MT, Pluschke G, Ktistakis N, Simmonds RE. Inhibition of the SEC61 translocon by mycolactone induces a protective autophagic response controlled by EIF2S1-dependent translation that does not require ULK1 activity. Autophagy 2021; 18:841-859. [PMID: 34424124 PMCID: PMC9037441 DOI: 10.1080/15548627.2021.1961067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The Mycobacterium ulcerans exotoxin, mycolactone, is responsible for the immunosuppression and tissue necrosis that characterizes Buruli ulcer. Mycolactone inhibits SEC61-dependent co-translational translocation of proteins into the endoplasmic reticulum and the resultant cytosolic translation triggers degradation of mislocalized proteins by the ubiquitin-proteasome system. Inhibition of SEC61 by mycolactone also activates multiple EIF2S1/eIF2α kinases in the integrated stress response (ISR). Here we show mycolactone increased canonical markers of selective macroautophagy/autophagy LC3B-II, ubiquitin and SQSTM1/p62 in diverse disease-relevant primary cells and cell lines. Increased formation of puncta positive for the early autophagy markers WIPI2, RB1CC1/FIP200 and ATG16L1 indicates increased initiation of autophagy. The mycolactone response was SEC61A1-dependent and involved a pathway that required RB1CC1 but not ULK. Deletion of Sqstm1 reduced cell survival in the presence of mycolactone, suggesting this response protects against the increased cytosolic protein burden caused by the toxin. However, reconstitution of baseline SQSTM1 expression in cells lacking all autophagy receptor proteins could not rescue viability. Translational regulation by EIF2S1 in the ISR plays a key role in the autophagic response to mycolactone. Mycolactone-dependent induction of SQSTM1 was reduced in eif2ak3−/-/perk−/- cells while the p-EIF2S1 antagonist ISRIB reversed the upregulation of SQSTM1 and reduced RB1CC1, WIPI2 and LC3B puncta formation. Increased SQSTM1 staining could be seen in Buruli ulcer patient skin biopsy samples, reinforcing genetic data that suggests autophagy is relevant to disease pathology. Since selective autophagy and the ISR are both implicated in neurodegeneration, cancer and inflammation, the pathway uncovered here may have a broad relevance to human disease. Abbreviations: ATF4: activating transcription factor 4; ATG: autophagy related; BAF: bafilomycin A1; ATG16L1: autophagy related 16 like 1; BU: Buruli ulcer; CQ: chloroquine; EIF2AK3: eukaryotic translation initiation factor 2 alpha kinase 3; CALCOCO2: calcium binding and coiled-coil domain 2; DMSO: dimethyl sulfoxide; EIF2S1: eukaryotic translation initiation factor 2 subunit alpha; ER: endoplasmic reticulum; GFP: green fluorescent protein; HDMEC: human dermal microvascular endothelial cells; HFFF: human fetal foreskin fibroblasts; ISR: integrated stress response; ISRIB: integrated stress response inhibitor; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MEF: mouse embryonic fibroblast; Myco: mycolactone; NBR1: NBR1 autophagy cargo receptor; NFE2L2: nuclear factor, erythroid 2 like 2; OPTN: optineurin; PFA: paraformaldehyde; PtdIns3P: phosphatidylinositol-3-phosphate; RB1CC1: RB1-inducible coiled coil 1; SQSTM1: sequestosome 1; TAX1BP1: Tax1 binding protein 1; ULK: unc-51 like autophagy activating kinase; UPS: ubiquitin-proteasome system; WIPI: WD repeat domain, phosphoinositide interacting; WT: wild type.
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Affiliation(s)
- Belinda S Hall
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | - Scott J Dos Santos
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | - Louise Tzung-Harn Hsieh
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | | | - Marie-Thérèse Ruf
- Molecular Immunology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,Medical Parasitology and Infection Biology Department, University of Basel, Basel, Switzerland
| | - Gerd Pluschke
- Molecular Immunology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,Medical Parasitology and Infection Biology Department, University of Basel, Basel, Switzerland
| | | | - Rachel E Simmonds
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
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