1
|
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.
Collapse
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.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Ryoo HD. The integrated stress response in metabolic adaptation. J Biol Chem 2024; 300:107151. [PMID: 38462161 PMCID: PMC10998230 DOI: 10.1016/j.jbc.2024.107151] [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: 11/15/2023] [Revised: 02/28/2024] [Accepted: 03/03/2024] [Indexed: 03/12/2024] Open
Abstract
The integrated stress response (ISR) refers to signaling pathways initiated by stress-activated eIF2α kinases. Distinct eIF2α kinases respond to different stress signals, including amino acid deprivation and mitochondrial stress. Such stress-induced eIF2α phosphorylation attenuates general mRNA translation and, at the same time, stimulates the preferential translation of specific downstream factors to orchestrate an adaptive gene expression program. In recent years, there have been significant new advances in our understanding of ISR during metabolic stress adaptation. Here, I discuss those advances, reviewing among others the ISR activation mechanisms in response to amino acid deprivation and mitochondrial stress. In addition, I review how ISR regulates the amino acid metabolic pathways and how changes in the ISR impact the physiology and pathology of various disease models.
Collapse
Affiliation(s)
- Hyung Don Ryoo
- Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Yousuf MS, Sahn JJ, Yang H, David ET, Shiers S, Moreno MM, 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 alleviates neuropathic pain and inhibits the integrated stress response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.11.536439. [PMID: 37090527 PMCID: PMC10120691 DOI: 10.1101/2023.04.11.536439] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
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 anti-nociceptive effect is approximately 24 hours following dosing. We sought to understand this unique anti-neuropathic 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 (KO) mice for Tmem97, we find that a new σ2R/TMEM97 binding compound, FEM-1689, requires the presence of the gene to produce anti-nociception in the spared nerve injury model in mice. Using primary mouse dorsal root ganglion (DRG) 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.
Collapse
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, TX 75080
- NuvoNuro, Austin, TX 78712
| | - James J. Sahn
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712
- NuvoNuro, Austin, TX 78712
| | - Hongfen Yang
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712
| | - Eric T. David
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Stephanie Shiers
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Marisol Mancilla Moreno
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Jonathan Iketem
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Danielle M. Royer
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Chelsea D. Garcia
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Jennifer Zhang
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Veronica M. Hong
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Subhaan M. Mian
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Ayesha Ahmad
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | - Benedict J. Kolber
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
| | | | - Stephen F. Martin
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712
- NuvoNuro, Austin, TX 78712
| | - Theodore J. Price
- Center for Advanced Pain Studies and Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080
- NuvoNuro, Austin, TX 78712
| |
Collapse
|
6
|
Cardenal Peralta C, Vandroux P, Neumann-Arnold L, Panvert M, Fagart J, Seufert W, Mechulam Y, Schmitt E. Binding of human Cdc123 to eIF2γ. J Struct Biol 2023; 215:108006. [PMID: 37507029 DOI: 10.1016/j.jsb.2023.108006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/18/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023]
Abstract
Eukaryotic initiation factor 2 (eIF2) plays a key role in protein synthesis and in its regulation. The assembly of this heterotrimeric factor is facilitated by Cdc123, a member of the ATP grasp family that binds the γ subunit of eIF2. Notably, some mutations related to MEHMO syndrome, an X-linked intellectual disability, affect Cdc123-mediated eIF2 assembly. The mechanism of action of Cdc123 is unclear and structural information for the human protein is awaited. Here, the crystallographic structure of human Cdc123 (Hs-Cdc123) bound to domain 3 of human eIF2γ (Hs-eIF2γD3) was determined. The structure shows that the domain 3 of eIF2γ is bound to domain 1 of Cdc123. In addition, the long C-terminal region of Hs-Cdc123 provides a link between the ATP and Hs-eIF2γD3 binding sites. A thermal shift assay shows that ATP is tightly bound to Cdc123 whereas the affinity of ADP is much smaller. Yeast cell viability experiments, western blot analysis and two-hybrid assays show that ATP is important for the function of Hs-Cdc123 in eIF2 assembly. These data and recent findings allow us to propose a refined model to explain the mechanism of action of Cdc123 in eIF2 assembly.
Collapse
Affiliation(s)
- Cristina Cardenal Peralta
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France
| | - Paul Vandroux
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France
| | - Lea Neumann-Arnold
- Department of Genetics, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Michel Panvert
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France
| | - Jérôme Fagart
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France
| | - Wolfgang Seufert
- Department of Genetics, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany.
| | - Yves Mechulam
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France
| | - Emmanuelle Schmitt
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France.
| |
Collapse
|
7
|
Wek RC, Anthony TG, Staschke KA. Surviving and Adapting to Stress: Translational Control and the Integrated Stress Response. Antioxid Redox Signal 2023; 39:351-373. [PMID: 36943285 PMCID: PMC10443206 DOI: 10.1089/ars.2022.0123] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/23/2023]
Abstract
Significance: Organisms adapt to changing environments by engaging cellular stress response pathways that serve to restore proteostasis and enhance survival. A primary adaptive mechanism is the integrated stress response (ISR), which features phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2). Four eIF2α kinases respond to different stresses, enabling cells to rapidly control translation to optimize management of resources and reprogram gene expression for stress adaptation. Phosphorylation of eIF2 blocks its guanine nucleotide exchange factor, eIF2B, thus lowering the levels of eIF2 bound to GTP that is required to deliver initiator transfer RNA (tRNA) to ribosomes. While bulk messenger RNA (mRNA) translation can be sharply lowered by heightened phosphorylation of eIF2α, there are other gene transcripts whose translation is unchanged or preferentially translated. Among the preferentially translated genes is ATF4, which directs transcription of adaptive genes in the ISR. Recent Advances and Critical Issues: This review focuses on how eIF2α kinases function as first responders of stress, the mechanisms by which eIF2α phosphorylation and other stress signals regulate the exchange activity of eIF2B, and the processes by which the ISR triggers differential mRNA translation. To illustrate the synergy between stress pathways, we describe the mechanisms and functional significance of communication between the ISR and another key regulator of translation, mammalian/mechanistic target of rapamycin complex 1 (mTORC1), during acute and chronic amino acid insufficiency. Finally, we discuss the pathological conditions that stem from aberrant regulation of the ISR, as well as therapeutic strategies targeting the ISR to alleviate disease. Future Directions: Important topics for future ISR research are strategies for modulating this stress pathway in disease conditions and drug development, molecular processes for differential translation and the coordinate regulation of GCN2 and other stress pathways during physiological and pathological conditions. Antioxid. Redox Signal. 39, 351-373.
Collapse
Affiliation(s)
- Ronald C. Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
| | - Tracy G. Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Kirk A. Staschke
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
| |
Collapse
|
8
|
Zou Y, Yuan Z, Sun Y, Zhai M, Tan Z, Guan R, Aschner M, Luo W, Zhang J. Resetting Proteostasis of CIRBP with ISRIB Suppresses Neural Stem Cell Apoptosis under Hypoxic Exposure. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3627026. [PMID: 36211820 PMCID: PMC9546721 DOI: 10.1155/2022/3627026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/19/2022] [Indexed: 11/17/2022]
Abstract
Neurological disorders are often progressive and lead to disabilities with limited available therapies. Epidemiological evidence implicated that prolonged exposure to hypoxia leads to neurological damage and a plethora of complications. Neural stem cells (NSCs) are a promising tool for neurological damage therapy in terms of their unique properties. However, the literature on the outcome of NSCs exposed to severe hypoxia is scarce. In this study, we identified a responsive gene that reacts to multiple cellular stresses, marked cold-inducible RNA-binding protein (CIRBP), which could attenuate NSC apoptosis under hypoxic pressure. Interestingly, ISRIB, a small-molecule modulator of the PERK-ATF4 signaling pathway, could prevent the reduction and apoptosis of NSCs in two steps: enhancing the expression of CIRBP through the protein kinase R- (PKR-) like endoplasmic reticulum kinase (PERK) and activating transcription factor 4 (ATF4) axis. Taken together, CIRBP was found to be a critical factor that could protect NSCs against apoptosis induced by hypoxia, and ISRIB could be acted upstream of the axis and may be recruited as an open potential therapeutic strategy to prevent or treat hypoxia-induced brain hazards.
Collapse
Affiliation(s)
- Yuankang Zou
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| | - Ziyan Yuan
- Institute of Medical Information and Library, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100020, China
| | - Yafei Sun
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| | - Maodeng Zhai
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| | - Zhice Tan
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| | - Ruili Guan
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Wenjing Luo
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| | - Jianbin Zhang
- Department of Occupational and Environmental Health, The Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, No. 169 Chang Le West Rd., Xi'an, Shaanxi 710032, China
| |
Collapse
|
9
|
Ygberg S, Lindstrand A. Expanding the phenotype of the recurrent truncating
eIF2γ
pathogenic variant p.(
Ile465Serfs
*4) identified in two brothers with
MEHMO
syndrome. Clin Case Rep 2022; 10:e5989. [PMID: 35765291 PMCID: PMC9207232 DOI: 10.1002/ccr3.5989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/11/2022] [Accepted: 04/26/2022] [Indexed: 11/18/2022] Open
Abstract
We describe two brothers with a recurrent truncating EIF2S3 variant and MEHMO (Mental retardation, Epileptic seizures, Hypogonadism and ‐genitalism, Microcephaly, Obesity). Both had the previously described facial dysmorphic features, microcephaly, developmental impairment, hypoglycemia, hypothyreosis, diabetes mellitus, epilepsy, hypertonus, obesity, and micropenis. Additionally, we describe hypothermia and reduced umbilical blood flow.
Collapse
Affiliation(s)
- Sofia Ygberg
- Neuropediatric Unit Karolinska University Hospital Stockholm Sweden
- Department of Clinical Genetics and Centre for Inherited Metabolic Diseases (CMMS) Karolinska University Hospital Stockholm Sweden
| | - Anna Lindstrand
- Department of Clinical Genetics and Centre for Inherited Metabolic Diseases (CMMS) Karolinska University Hospital Stockholm Sweden
- Department of Molecular Medicine and Surgery Karolinska Institutet Stockholm Sweden
| |
Collapse
|
10
|
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: 2] [Impact Index Per Article: 1.0] [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.
Collapse
|
11
|
Fritz SE, Ranganathan S, Wang CD, Hogg JR. An alternative UPF1 isoform drives conditional remodeling of nonsense-mediated mRNA decay. EMBO J 2022; 41:e108898. [PMID: 35403729 PMCID: PMC9108617 DOI: 10.15252/embj.2021108898] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 03/18/2022] [Accepted: 03/25/2022] [Indexed: 12/11/2022] Open
Abstract
The nonsense-mediated mRNA decay (NMD) pathway monitors translation termination in order to degrade transcripts with premature stop codons and regulate thousands of human genes. Here, we show that an alternative mammalian-specific isoform of the core NMD factor UPF1, termed UPF1LL , enables condition-dependent remodeling of NMD specificity. Previous studies indicate that the extension of a conserved regulatory loop in the UPF1LL helicase core confers a decreased propensity to dissociate from RNA upon ATP hydrolysis relative to UPF1SL , the major UPF1 isoform. Using biochemical and transcriptome-wide approaches, we find that UPF1LL can circumvent the protective RNA binding proteins PTBP1 and hnRNP L to preferentially bind and down-regulate transcripts with long 3'UTRs normally shielded from NMD. Unexpectedly, UPF1LL supports induction of NMD on new populations of substrate mRNAs in response to activation of the integrated stress response and impaired translation efficiency. Thus, while canonical NMD is abolished by moderate translational repression, UPF1LL activity is enhanced, offering the possibility to rapidly rewire NMD specificity in response to cellular stress.
Collapse
Affiliation(s)
- Sarah E Fritz
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - Soumya Ranganathan
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - Clara D Wang
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - J Robert Hogg
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| |
Collapse
|
12
|
Ram AK, Mallik M, Reddy RR, Suryawanshi AR, Alone PV. Altered proteome in translation initiation fidelity defective eIF5 G31R mutant causes oxidative stress and DNA damage. Sci Rep 2022; 12:5033. [PMID: 35322093 PMCID: PMC8943034 DOI: 10.1038/s41598-022-08857-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/07/2022] [Indexed: 12/15/2022] Open
Abstract
The recognition of the AUG start codon and selection of an open reading frame (ORF) is fundamental to protein biosynthesis. Defect in the fidelity of start codon selection adversely affect proteome and have a pleiotropic effect on cellular function. Using proteomic techniques, we identified differential protein abundance in the translation initiation fidelity defective eIF5G31R mutant that initiates translation using UUG codon in addition to the AUG start codon. Consistently, the eIF5G31R mutant altered proteome involved in protein catabolism, nucleotide biosynthesis, lipid biosynthesis, carbohydrate metabolism, oxidation–reduction pathway, autophagy and re-programs the cellular pathways. The utilization of the upstream UUG codons by the eIF5G31R mutation caused downregulation of uridylate kinase expression, sensitivity to hydroxyurea, and DNA damage. The eIF5G31R mutant cells showed lower glutathione levels, high ROS activity, and sensitivity to H2O2.
Collapse
Affiliation(s)
- Anup Kumar Ram
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, P.O Jatni, Khurda, 752050, India.,Homi Bhabha National Institute (HBNI), Anushakti Nagar, Mumbai, 400094, India
| | - Monalisha Mallik
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, P.O Jatni, Khurda, 752050, India.,Homi Bhabha National Institute (HBNI), Anushakti Nagar, Mumbai, 400094, India
| | - R Rajendra Reddy
- Clinical Proteomics, DBT-Institute of Life Sciences, Bhubaneswar, Odisha, 751023, India
| | | | - Pankaj V Alone
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, P.O Jatni, Khurda, 752050, India. .,Homi Bhabha National Institute (HBNI), Anushakti Nagar, Mumbai, 400094, India.
| |
Collapse
|
13
|
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.
Collapse
|
14
|
Stepwise assembly of the eukaryotic translation initiation factor 2 (eIF2) complex. J Biol Chem 2022; 298:101583. [PMID: 35031321 PMCID: PMC8844851 DOI: 10.1016/j.jbc.2022.101583] [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: 10/26/2021] [Revised: 01/02/2022] [Accepted: 01/04/2022] [Indexed: 11/22/2022] Open
Abstract
The eukaryotic translation initiation factor 2 (eIF2) has key functions in the initiation step of protein synthesis. eIF2 guides the initiator tRNA to the ribosome, participates in scanning of the mRNA molecule, supports selection of the start codon, and modulates the translation of mRNAs in response to stress. eIF2 comprises a heterotrimeric complex whose assembly depends on the ATP-grasp protein Cdc123. Mutations of the eIF2γ subunit that compromise eIF2 complex formation cause severe neurological disease in humans. To this date, however, details about the assembly mechanism, step order, and the individual functions of eIF2 subunits remain unclear. Here, we quantified assembly intermediates and studied the behavior of various binding site mutants in budding yeast. Based on these data, we present a model in which a Cdc123-mediated conformational change in eIF2γ exposes binding sites for eIF2α and -β subunits. Contrary to an earlier hypothesis, we found that the associations of eIF2α and -β with the γ-subunit are independent of each other, but the resulting heterodimers are non-functional and fail to bind the guanosine exchange factor eIF2B. In addition, levels of eIF2α influence the rate of eIF2 assembly. By binding to eIF2γ, eIF2α displaces Cdc123 and thereby completes the assembly process. Experiments in human cell culture indicate that the mechanism of eIF2 assembly is conserved between yeast and humans. This study sheds light on an essential step in eukaryotic translation initiation, the dysfunction of which is linked to human disease.
Collapse
|
15
|
Ivanova N, Serzhanova V, Demina N, Guseva D, Skoblov M. mRNA analysis revealed a novel pathogenic EIF2S3 variant causing MEHMO syndrome. Eur J Med Genet 2022; 65:104421. [PMID: 34999262 DOI: 10.1016/j.ejmg.2022.104421] [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: 07/14/2021] [Revised: 12/21/2021] [Accepted: 01/04/2022] [Indexed: 11/03/2022]
Abstract
EIF2S3 pathogenic variants have been shown to cause MEHMO syndrome - a rare X-linked intellectual disability syndrome. In most cases, DNA diagnostics of MEHMO syndrome is performed using exome sequencing. We describe two cousins with profound intellectual disability, severe microcephaly, microgenitalism, hypoglycemia, epileptic seizures, and hypertrichosis, whose clinical symptoms allowed us to suspect MEHMO syndrome. To confirm this diagnosis, we designed an mRNA analysis for the EIF2S3 gene. It is a cost-effective method to detect coding sequence variants in multi-exonic genes, as well as splicing defects and allelic imbalance. Our mRNA sequence analysis revealed a novel EIF2S3 variant c.820C>G in both cousins. We also found the same variant in female family members in the heterozygous state. To investigate the pathogenicity of the c.820C>G variant, we performed expression analysis, which showed that the DDIT3 transcript level was significantly increased in the patient relative to the controls. We, thus, demonstrate that mRNA analysis is an efficient tool for performing genetic testing in patients with distinct phenotypic features.
Collapse
Affiliation(s)
- Nadezda Ivanova
- Research Centre for Medical Genetics, 115522, Moscow, Russia.
| | | | - Nina Demina
- Research Centre for Medical Genetics, 115522, Moscow, Russia
| | - Darya Guseva
- Research Centre for Medical Genetics, 115522, Moscow, Russia
| | - Mikhail Skoblov
- Research Centre for Medical Genetics, 115522, Moscow, Russia
| |
Collapse
|
16
|
Landínez-Macías M, Urwyler O. The Fine Art of Writing a Message: RNA Metabolism in the Shaping and Remodeling of the Nervous System. Front Mol Neurosci 2021; 14:755686. [PMID: 34916907 PMCID: PMC8670310 DOI: 10.3389/fnmol.2021.755686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/18/2021] [Indexed: 01/25/2023] Open
Abstract
Neuronal morphogenesis, integration into circuits, and remodeling of synaptic connections occur in temporally and spatially defined steps. Accordingly, the expression of proteins and specific protein isoforms that contribute to these processes must be controlled quantitatively in time and space. A wide variety of post-transcriptional regulatory mechanisms, which act on pre-mRNA and mRNA molecules contribute to this control. They are thereby critically involved in physiological and pathophysiological nervous system development, function, and maintenance. Here, we review recent findings on how mRNA metabolism contributes to neuronal development, from neural stem cell maintenance to synapse specification, with a particular focus on axon growth, guidance, branching, and synapse formation. We emphasize the role of RNA-binding proteins, and highlight their emerging roles in the poorly understood molecular processes of RNA editing, alternative polyadenylation, and temporal control of splicing, while also discussing alternative splicing, RNA localization, and local translation. We illustrate with the example of the evolutionary conserved Musashi protein family how individual RNA-binding proteins are, on the one hand, acting in different processes of RNA metabolism, and, on the other hand, impacting multiple steps in neuronal development and circuit formation. Finally, we provide links to diseases that have been associated with the malfunction of RNA-binding proteins and disrupted post-transcriptional regulation.
Collapse
Affiliation(s)
- María Landínez-Macías
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Molecular Life Sciences Program, Life Science Zurich Graduate School, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, Zurich, Switzerland
| | - Olivier Urwyler
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Molecular Life Sciences Program, Life Science Zurich Graduate School, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich, Zurich, Switzerland
| |
Collapse
|
17
|
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: 176] [Impact Index Per Article: 58.7] [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.
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Network Analysis Identifies Sex-Specific Gene Expression Changes in Blood of Amyotrophic Lateral Sclerosis Patients. Int J Mol Sci 2021; 22:ijms22137150. [PMID: 34281203 PMCID: PMC8269377 DOI: 10.3390/ijms22137150] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 01/18/2023] Open
Abstract
Understanding the molecular mechanisms underlying the pathogenesis of amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease, is a major challenge. We used co-expression networks implemented by the SWitch Miner software to identify switch genes associated with drastic transcriptomic changes in the blood of ALS patients. Functional analyses revealed that switch genes were enriched in pathways related to the cell cycle, hepatitis C, and small cell lung cancer. Analysis of switch genes by sex revealed that switch genes from males were associated with metabolic pathways, including PI3K-AKT, sphingolipid, carbon metabolism, FOXO, and AMPK signaling. In contrast, female switch genes related to infectious diseases, inflammation, apoptosis, and atherosclerosis. Furthermore, eight switch genes showed sex-specific gene expression patterns. Collectively, we identified essential genes and pathways that may explain sex differences observed in ALS. Future studies investigating the potential role of these genes in driving disease disparities between males and females with ALS are warranted.
Collapse
|
20
|
Schieweck R, Ninkovic J, Kiebler MA. RNA-binding proteins balance brain function in health and disease. Physiol Rev 2020; 101:1309-1370. [PMID: 33000986 DOI: 10.1152/physrev.00047.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Posttranscriptional gene expression including splicing, RNA transport, translation, and RNA decay provides an important regulatory layer in many if not all molecular pathways. Research in the last decades has positioned RNA-binding proteins (RBPs) right in the center of posttranscriptional gene regulation. Here, we propose interdependent networks of RBPs to regulate complex pathways within the central nervous system (CNS). These are involved in multiple aspects of neuronal development and functioning, including higher cognition. Therefore, it is not sufficient to unravel the individual contribution of a single RBP and its consequences but rather to study and understand the tight interplay between different RBPs. In this review, we summarize recent findings in the field of RBP biology and discuss the complex interplay between different RBPs. Second, we emphasize the underlying dynamics within an RBP network and how this might regulate key processes such as neurogenesis, synaptic transmission, and synaptic plasticity. Importantly, we envision that dysfunction of specific RBPs could lead to perturbation within the RBP network. This would have direct and indirect (compensatory) effects in mRNA binding and translational control leading to global changes in cellular expression programs in general and in synaptic plasticity in particular. Therefore, we focus on RBP dysfunction and how this might cause neuropsychiatric and neurodegenerative disorders. Based on recent findings, we propose that alterations in the entire regulatory RBP network might account for phenotypic dysfunctions observed in complex diseases including neurodegeneration, epilepsy, and autism spectrum disorders.
Collapse
Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| |
Collapse
|
21
|
Kotzaeridou U, Young-Baird SK, Suckow V, Thornburg AG, Wagner M, Harting I, Christ S, Strom T, Dever TE, Kalscheuer VM. Novel pathogenic EIF2S3 missense variants causing clinically variable MEHMO syndrome with impaired eIF2γ translational function, and literature review. Clin Genet 2020; 98:507-514. [PMID: 32799315 DOI: 10.1111/cge.13831] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/08/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
Rare pathogenic EIF2S3 missense and terminal deletion variants cause the X-linked intellectual disability (ID) syndrome MEHMO, or a milder phenotype including pancreatic dysfunction and hypopituitarism. We present two unrelated male patients who carry novel EIF2S3 pathogenic missense variants (p.(Thr144Ile) and p.(Ile159Leu)) thereby broadening the limited genetic spectrum and underscoring clinically variable expressivity of MEHMO. While the affected male with p.(Thr144Ile) presented with severe motor delay, severe microcephaly, moderate ID, epileptic seizures responsive to treatments, hypogenitalism, central obesity, facial features, and diabetes, the affected male with p.(Ile159Leu) presented with moderate ID, mild motor delay, microcephaly, epileptic seizures resistant to treatment, central obesity, and mild facial features. Both variants are located in the highly conserved guanine nucleotide binding domain of the EIF2S3 encoded eIF2γ subunit of the heterotrimeric translation initiation factor 2 (eIF2) complex. Further, we investigated both variants in a structural model and in yeast. The reduced growth rates and lowered fidelity of translation with increased initiation at non-AUG codons observed for both mutants in these studies strongly support pathogenicity of the variants.
Collapse
Affiliation(s)
- Urania Kotzaeridou
- Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sara K Young-Baird
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA.,National Institute of General Medical Sciences, NIH, Bethesda, Maryland, USA
| | - Vanessa Suckow
- Research Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Alexis G Thornburg
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Matias Wagner
- Institute of Human Genetics, Technical University München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Inga Harting
- Department of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stine Christ
- Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Tim Strom
- Institute of Human Genetics, Technical University München, Munich, Germany
| | - Thomas E Dever
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Vera M Kalscheuer
- Research Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| |
Collapse
|
22
|
Marintchev A, Ito T. eIF2B and the Integrated Stress Response: A Structural and Mechanistic View. Biochemistry 2020; 59:1299-1308. [PMID: 32200625 DOI: 10.1021/acs.biochem.0c00132] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The eukaryotic translation initiation factor eIF2 is a GTPase, which brings the initiator Met-tRNAi to the ribosome as the eIF2-GTP·Met-tRNAi ternary complex (TC). TC regeneration is catalyzed by the guanine nucleotide exchange factor (GEF) eIF2B. eIF2 phosphorylation by several stress-induced kinases converts it into a competitive inhibitor of eIF2B. Inhibition of eIF2B activity lowers cellular TC concentrations, which in turn triggers the integrated stress response (ISR). Depending on its degree of activation and duration, the ISR protects the cell from the stress or can itself induce apoptosis. ISR dysregulation is a causative factor in the pathology of multiple neurodegenerative disorders, while ISR inhibitors are neuroprotective. The realization that eIF2B is a promising therapeutic target has triggered significant interest in its structure and its mechanisms of action and regulation. Recently, four groups published the cryo-electron microscopy structures of eIF2B with its substrate eIF2 and/or its inhibitor, phosphorylated eIF2 [eIF2(α-P)]. While all three structures of the nonproductive eIF2B·eIF2(α-P) complex are similar to each other, there is a sharp disagreement between the published structures of the productive eIF2B·eIF2 complex. One group reports a structure similar to that of the nonproductive complex, whereas two others observe a vastly different eIF2B·eIF2 complex. Here, we discuss the recent reports on the structure, function, and regulation of eIF2B; the preclinical data on the use of ISR inhibitors for the treatment of neurodegenerative disorders; and how the new structural and biochemical information can inform and influence the use of eIF2B as a therapeutic target.
Collapse
Affiliation(s)
- Assen Marintchev
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - Takuhiro Ito
- RIKEN Center for Biosystems Dynamics Research, Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| |
Collapse
|