1
|
Krakowczyk M, Lenkiewicz AM, Sitarz T, Malinska D, Borrero M, Mussulini BHM, Linke V, Szczepankiewicz AA, Biazik JM, Wydrych A, Nieznanska H, Serwa RA, Chacinska A, Bragoszewski P. OMA1 protease eliminates arrested protein import intermediates upon mitochondrial depolarization. J Cell Biol 2024; 223:e202306051. [PMID: 38530280 DOI: 10.1083/jcb.202306051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/28/2023] [Accepted: 02/16/2024] [Indexed: 03/27/2024] Open
Abstract
Most mitochondrial proteins originate from the cytosol and require transport into the organelle. Such precursor proteins must be unfolded to pass through translocation channels in mitochondrial membranes. Misfolding of transported proteins can result in their arrest and translocation failure. Arrested proteins block further import, disturbing mitochondrial functions and cellular proteostasis. Cellular responses to translocation failure have been defined in yeast. We developed the cell line-based translocase clogging model to discover molecular mechanisms that resolve failed import events in humans. The mechanism we uncover differs significantly from these described in fungi, where ATPase-driven extraction of blocked protein is directly coupled with proteasomal processing. We found human cells to rely primarily on mitochondrial factors to clear translocation channel blockage. The mitochondrial membrane depolarization triggered proteolytic cleavage of the stalled protein, which involved mitochondrial protease OMA1. The cleavage allowed releasing the protein fragment that blocked the translocase. The released fragment was further cleared in the cytosol by VCP/p97 and the proteasome.
Collapse
Affiliation(s)
- Magda Krakowczyk
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
| | - Anna M Lenkiewicz
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
| | - Tomasz Sitarz
- Centre of New Technologies, University of Warsaw , Warsaw, Poland
| | - Dominika Malinska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
| | - Mayra Borrero
- IMol Polish Academy of Sciences , Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences , Warsaw, Poland
| | - Ben Hur Marins Mussulini
- IMol Polish Academy of Sciences , Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences , Warsaw, Poland
| | - Vanessa Linke
- IMol Polish Academy of Sciences , Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences , Warsaw, Poland
| | | | - Joanna M Biazik
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
- University of New South Wales , Sydney, Australia
| | - Agata Wydrych
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
| | - Hanna Nieznanska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
| | - Remigiusz A Serwa
- IMol Polish Academy of Sciences , Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences , Warsaw, Poland
| | - Agnieszka Chacinska
- IMol Polish Academy of Sciences , Warsaw, Poland
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences , Warsaw, Poland
| | - Piotr Bragoszewski
- Nencki Institute of Experimental Biology, Polish Academy of Sciences , Warsaw, Poland
- Centre of New Technologies, University of Warsaw , Warsaw, Poland
| |
Collapse
|
2
|
Kucharska-Lusina A, Skrzypek M, Binda A, Majsterek I. Gene Expression Profiling to Unfolded Proteins Response as a Risk Modulator of Patients with Rheumatoid Arthritis. Int J Mol Sci 2024; 25:4854. [PMID: 38732072 PMCID: PMC11084936 DOI: 10.3390/ijms25094854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/17/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Rheumatoid arthritis (RA) is a chronic inflammatory disease. Despite new methods of diagnostics and treatment as well as extensive biological and immunosuppressive treatment, the etiology of RA is not fully understood. Moreover, the problem of diagnosis and treatment of RA patients is still current and affects a large group of patients. It is suggested that endoplasmic reticulum (ER)-related features may impair adaptation to chronic stress, inferring the risk of rheumatoid arthritis. The main goal in this study was evaluation of changes in mRNA translation to determine chronic ER stress conditions in rheumatoid arthritis patients. The study group consist of 86 individuals including a total of 56 rheumatoid arthritis patients and 30 healthy controls. The expression level of mRNA form blood samples of RA patients as well as controls of the unfolded protein response (UPR)-associated genes (p-eIF2, BCL-2, PERK, ATF4, and BAX) were investigated using real-time qPCR. GAPDH expression was used as a standard control. Considering the median, the expression levels of PERK, BCL-2, p-eIF2, ATF4, and BAX were found to be significantly increased in the blood of RA patients compared with the control group. The p-value for the PERK gene was 0.0000000036, the p-value for the BCL-2 gene was 0.000000014, the p-value for the p-eIF2 gene was 0.006948, the p-value for the ATF4 gene was 0.0000056, and the p-value for the BAX gene was 0.00019, respectively. Thus, it can be concluded that the targeting of the components of the PERK-dependent UPR signaling pathway via small-molecule PERK inhibitors may contribute to the development of novel, innovative treatment strategies against rheumatoid arthritis.
Collapse
Affiliation(s)
| | | | | | - Ireneusz Majsterek
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (A.K.-L.); (M.S.); (A.B.)
| |
Collapse
|
3
|
Smirnova AM, Hronová V, Mohammad MP, Herrmannová A, Gunišová S, Petráčková D, Halada P, Coufal Š, Świrski M, Rendleman J, Jendruchová K, Hatzoglou M, Beznosková P, Vogel C, Valášek LS. Stem-loop-induced ribosome queuing in the uORF2/ATF4 overlap fine-tunes stress-induced human ATF4 translational control. Cell Rep 2024; 43:113976. [PMID: 38507410 PMCID: PMC11058473 DOI: 10.1016/j.celrep.2024.113976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/15/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024] Open
Abstract
Activating transcription factor 4 (ATF4) is a master transcriptional regulator of the integrated stress response, leading cells toward adaptation or death. ATF4's induction under stress was thought to be due to delayed translation reinitiation, where the reinitiation-permissive upstream open reading frame 1 (uORF1) plays a key role. Accumulating evidence challenging this mechanism as the sole source of ATF4 translation control prompted us to investigate additional regulatory routes. We identified a highly conserved stem-loop in the uORF2/ATF4 overlap, immediately preceded by a near-cognate CUG, which introduces another layer of regulation in the form of ribosome queuing. These elements explain how the inhibitory uORF2 can be translated under stress, confirming prior observations but contradicting the original regulatory model. We also identified two highly conserved, potentially modified adenines performing antagonistic roles. Finally, we demonstrated that the canonical ATF4 translation start site is substantially leaky scanned. Thus, ATF4's translational control is more complex than originally described, underpinning its key role in diverse biological processes.
Collapse
Affiliation(s)
- Anna M Smirnova
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Vladislava Hronová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Mahabub Pasha Mohammad
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Stanislava Gunišová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Denisa Petráčková
- Laboratory of Post-transcriptional Control of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Petr Halada
- Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology of the Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Štěpán Coufal
- Laboratory of Cellular and Molecular Immunology, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Michał Świrski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | | | - Kristína Jendruchová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Christine Vogel
- Department of Biology, New York University, New York, NY, USA.
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic.
| |
Collapse
|
4
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
5
|
Chen Y, McDonald JA. Collective cell migration relies on PPP1R15-mediated regulation of the endoplasmic reticulum stress response. Curr Biol 2024; 34:1390-1402.e4. [PMID: 38428416 PMCID: PMC11003853 DOI: 10.1016/j.cub.2024.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 12/19/2023] [Accepted: 02/07/2024] [Indexed: 03/03/2024]
Abstract
Collective cell migration is integral to many developmental and disease processes. Previously, we discovered that protein phosphatase 1 (Pp1) promotes border cell collective migration in the Drosophila ovary. We now report that the Pp1 phosphatase regulatory subunit dPPP1R15 is a critical regulator of border cell migration. dPPP1R15 is an ortholog of mammalian PPP1R15 proteins that attenuate the endoplasmic reticulum (ER) stress response. We show that, in collectively migrating border cells, dPPP1R15 phosphatase restrains an active physiological protein kinase R-like ER kinase- (PERK)-eIF2α-activating transcription factor 4 (ATF4) stress pathway. RNAi knockdown of dPPP1R15 blocks border cell delamination from the epithelium and subsequent migration, increases eIF2α phosphorylation, reduces translation, and drives expression of the stress response transcription factor ATF4. We observe similar defects upon overexpression of ATF4 or the eIF2α kinase PERK. Furthermore, we show that normal border cells express markers of the PERK-dependent ER stress response and require PERK and ATF4 for efficient migration. In many other cell types, unresolved ER stress induces initiation of apoptosis. In contrast, border cells with chronic RNAi knockdown of dPPP1R15 survive. Together, our results demonstrate that the PERK-eIF2α-ATF4 pathway, regulated by dPPP1R15 activity, counteracts the physiological ER stress that occurs during collective border cell migration. We propose that in vivo collective cell migration is intrinsically "stressful," requiring tight homeostatic control of the ER stress response for collective cell cohesion, dynamics, and movement.
Collapse
Affiliation(s)
- Yujun Chen
- Division of Biology, Kansas State University, 1717 Claflin Road, Manhattan, KS 66506, USA
| | - Jocelyn A McDonald
- Division of Biology, Kansas State University, 1717 Claflin Road, Manhattan, KS 66506, USA.
| |
Collapse
|
6
|
Calakos N, Caffall ZF. The integrated stress response pathway and neuromodulator signaling in the brain: lessons learned from dystonia. J Clin Invest 2024; 134:e177833. [PMID: 38557486 PMCID: PMC10977992 DOI: 10.1172/jci177833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024] Open
Abstract
The integrated stress response (ISR) is a highly conserved biochemical pathway involved in maintaining proteostasis and cell health in the face of diverse stressors. In this Review, we discuss a relatively noncanonical role for the ISR in neuromodulatory neurons and its implications for synaptic plasticity, learning, and memory. Beyond its roles in stress response, the ISR has been extensively studied in the brain, where it potently influences learning and memory, and in the process of synaptic plasticity, which is a substrate for adaptive behavior. Recent findings demonstrate that some neuromodulatory neuron types engage the ISR in an "always-on" mode, rather than the more canonical "on-demand" response to transient perturbations. Atypical demand for the ISR in neuromodulatory neurons introduces an additional mechanism to consider when investigating ISR effects on synaptic plasticity, learning, and memory. This basic science discovery emerged from a consideration of how the ISR might be contributing to human disease. To highlight how, in scientific discovery, the route from starting point to outcomes can often be circuitous and full of surprise, we begin by describing our group's initial introduction to the ISR, which arose from a desire to understand causes for a rare movement disorder, dystonia. Ultimately, the unexpected connection led to a deeper understanding of its fundamental role in the biology of neuromodulatory neurons, learning, and memory.
Collapse
Affiliation(s)
- Nicole Calakos
- Department of Neurology
- Department of Neurobiology, and
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland, USA
| | | |
Collapse
|
7
|
Belužić R, Šimunić E, Podgorski II, Pinterić M, Hadžija MP, Balog T, Sobočanec S. Gene Expression Profiling Reveals Fundamental Sex-Specific Differences in SIRT3-Mediated Redox and Metabolic Signaling in Mouse Embryonic Fibroblasts. Int J Mol Sci 2024; 25:3868. [PMID: 38612678 PMCID: PMC11012119 DOI: 10.3390/ijms25073868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Sirt-3 is an important regulator of mitochondrial function and cellular energy homeostasis, whose function is associated with aging and various pathologies such as Alzheimer's disease, Parkinson's disease, cardiovascular diseases, and cancers. Many of these conditions show differences in incidence, onset, and progression between the sexes. In search of hormone-independent, sex-specific roles of Sirt-3, we performed mRNA sequencing in male and female Sirt-3 WT and KO mouse embryonic fibroblasts (MEFs). The aim of this study was to investigate the sex-specific cellular responses to the loss of Sirt-3. By comparing WT and KO MEF of both sexes, the differences in global gene expression patterns as well as in metabolic and stress responses associated with the loss of Sirt-3 have been elucidated. Significant differences in the activities of basal metabolic pathways were found both between genotypes and between sexes. In-depth pathway analysis of metabolic pathways revealed several important sex-specific phenomena. Male cells mount an adaptive Hif-1a response, shifting their metabolism toward glycolysis and energy production from fatty acids. Furthermore, the loss of Sirt-3 in male MEFs leads to mitochondrial and endoplasmic reticulum stress. Since Sirt-3 knock-out is permanent, male cells are forced to function in a state of persistent oxidative and metabolic stress. Female MEFs are able to at least partially compensate for the loss of Sirt-3 by a higher expression of antioxidant enzymes. The activation of neither Hif-1a, mitochondrial stress response, nor oxidative stress response was observed in female cells lacking Sirt-3. These findings emphasize the sex-specific role of Sirt-3, which should be considered in future research.
Collapse
|
8
|
Corne A, Adolphe F, Estaquier J, Gaumer S, Corsi JM. ATF4 Signaling in HIV-1 Infection: Viral Subversion of a Stress Response Transcription Factor. Biology (Basel) 2024; 13:146. [PMID: 38534416 DOI: 10.3390/biology13030146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/13/2024] [Accepted: 02/20/2024] [Indexed: 03/28/2024]
Abstract
Cellular integrated stress response (ISR), the mitochondrial unfolded protein response (UPRmt), and IFN signaling are associated with viral infections. Activating transcription factor 4 (ATF4) plays a pivotal role in these pathways and controls the expression of many genes involved in redox processes, amino acid metabolism, protein misfolding, autophagy, and apoptosis. The precise role of ATF4 during viral infection is unclear and depends on cell hosts, viral agents, and models. Furthermore, ATF4 signaling can be hijacked by pathogens to favor viral infection and replication. In this review, we summarize the ATF4-mediated signaling pathways in response to viral infections, focusing on human immunodeficiency virus 1 (HIV-1). We examine the consequences of ATF4 activation for HIV-1 replication and reactivation. The role of ATF4 in autophagy and apoptosis is explored as in the context of HIV-1 infection programmed cell deaths contribute to the depletion of CD4 T cells. Furthermore, ATF4 can also participate in the establishment of innate and adaptive immunity that is essential for the host to control viral infections. We finally discuss the putative role of the ATF4 paralogue, named ATF5, in HIV-1 infection. This review underlines the role of ATF4 at the crossroads of multiple processes reflecting host-pathogen interactions.
Collapse
Affiliation(s)
- Adrien Corne
- Laboratoire de Génétique et Biologie Cellulaire, Université Versailles-Saint-Quentin-en-Yvelines, Université Paris-Saclay, 78000 Versailles, France
- CHU de Québec Research Center, Laval University, Quebec City, QC G1V 4G2, Canada
| | - Florine Adolphe
- Laboratoire de Génétique et Biologie Cellulaire, Université Versailles-Saint-Quentin-en-Yvelines, Université Paris-Saclay, 78000 Versailles, France
| | - Jérôme Estaquier
- CHU de Québec Research Center, Laval University, Quebec City, QC G1V 4G2, Canada
- INSERM U1124, Université Paris Cité, 75006 Paris, France
| | - Sébastien Gaumer
- Laboratoire de Génétique et Biologie Cellulaire, Université Versailles-Saint-Quentin-en-Yvelines, Université Paris-Saclay, 78000 Versailles, France
| | - Jean-Marc Corsi
- Laboratoire de Génétique et Biologie Cellulaire, Université Versailles-Saint-Quentin-en-Yvelines, Université Paris-Saclay, 78000 Versailles, France
| |
Collapse
|
9
|
Smirnova AM, Hronova V, Mohammad MP, Herrmannova A, Gunisova S, Petrackova D, Halada P, Coufal S, Swirski M, Rendelman J, Jendruchova K, Hatzoglou M, Beznoskova P, Vogel C, Valasek LS. Stem-loop induced ribosome queuing in the uORF2/ATF4 overlap fine-tunes stress-induced human ATF4 translational control. bioRxiv 2024:2023.07.12.548609. [PMID: 37502919 PMCID: PMC10369994 DOI: 10.1101/2023.07.12.548609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
ATF4 is a master transcriptional regulator of the integrated stress response leading cells towards adaptation or death. ATF4's induction under stress was thought to be mostly due to delayed translation reinitiation, where the reinitiation-permissive uORF1 plays a key role. Accumulating evidence challenging this mechanism as the sole source of ATF4 translation control prompted us to investigate additional regulatory routes. We identified a highly conserved stem-loop in the uORF2/ATF4 overlap, immediately preceded by a near-cognate CUG, which introduces another layer of regulation in the form of ribosome queuing. These elements explain how the inhibitory uORF2 can be translated under stress, confirming prior observations, but contradicting the original regulatory model. We also identified two highly conserved, potentially modified adenines performing antagonistic roles. Finally, we demonstrate that the canonical ATF4 translation start site is substantially leaky-scanned. Thus, ATF4's translational control is more complex than originally described underpinning its key role in diverse biological processes.
Collapse
|
10
|
Mattson MP, Leak RK. The hormesis principle of neuroplasticity and neuroprotection. Cell Metab 2024; 36:315-337. [PMID: 38211591 DOI: 10.1016/j.cmet.2023.12.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/06/2023] [Accepted: 12/18/2023] [Indexed: 01/13/2024]
Abstract
Animals live in habitats fraught with a range of environmental challenges to their bodies and brains. Accordingly, cells and organ systems have evolved stress-responsive signaling pathways that enable them to not only withstand environmental challenges but also to prepare for future challenges and function more efficiently. These phylogenetically conserved processes are the foundation of the hormesis principle, in which single or repeated exposures to low levels of environmental challenges improve cellular and organismal fitness and raise the probability of survival. Hormetic principles have been most intensively studied in physical exercise but apply to numerous other challenges known to improve human health (e.g., intermittent fasting, cognitive stimulation, and dietary phytochemicals). Here we review the physiological mechanisms underlying hormesis-based neuroplasticity and neuroprotection. Approaching natural resilience from the lens of hormesis may reveal novel methods for optimizing brain function and lowering the burden of neurological disorders.
Collapse
Affiliation(s)
- Mark P Mattson
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Rehana K Leak
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| |
Collapse
|
11
|
Xiao Y, Xie X, Chen Z, Yin G, Kong W, Zhou J. Advances in the roles of ATF4 in osteoporosis. Biomed Pharmacother 2023; 169:115864. [PMID: 37948991 DOI: 10.1016/j.biopha.2023.115864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023] Open
Abstract
Osteoporosis (OP) is characterized by reduced bone mass, decreased strength, and enhanced bone fragility fracture risk. Activating transcription factor 4 (ATF4) plays a role in cell differentiation, proliferation, apoptosis, redox balance, amino acid uptake, and glycolipid metabolism. ATF4 induces the differentiation of bone marrow mesenchymal stem cells (BM-MSCs) into osteoblasts, increases osteoblast activity, and inhibits osteoclast formation, promoting bone formation and remodeling. In addition, ATF4 mediates the energy metabolism in osteoblasts and promotes angiogenesis. ATF4 is also involved in the mediation of adipogenesis. ATF4 can selectively accumulate in osteoblasts. ATF4 can directly interact with RUNT-related transcription factor 2 (RUNX2) and up-regulate the expression of osteocalcin (OCN) and osterix (Osx). Several upstream factors, such as Wnt/β-catenin and BMP2/Smad signaling pathways, have been involved in ATF4-mediated osteoblast differentiation. ATF4 promotes osteoclastogenesis by mediating the receptor activator of nuclear factor κ-B (NF-κB) ligand (RANKL) signaling. Several agents, such as parathyroid (PTH), melatonin, and natural compounds, have been reported to regulate ATF4 expression and mediate bone metabolism. In this review, we comprehensively discuss the biological activities of ATF4 in maintaining bone homeostasis and inhibiting OP development. ATF4 has become a therapeutic target for OP treatment.
Collapse
Affiliation(s)
- Yaosheng Xiao
- Department of Orthopaetics, First Affiliated Hospital of Gannan Medical University, Ganzhou 341000, China
| | - Xunlu Xie
- Department of Pathology, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Zhixi Chen
- Department of Pharmacy, Gannan Medical University, Ganzhou 341000, China
| | - Guoqiang Yin
- Ganzhou Hospital Affiliated to Nanchang University, Ganzhou 341000, China
| | - Weihao Kong
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Jianguo Zhou
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China.
| |
Collapse
|
12
|
Tang L, Yu Y, Deng W, Liu J, Wang Y, Ye F, Kang R, Tang D, He Q. TXNDC12 inhibits lipid peroxidation and ferroptosis. iScience 2023; 26:108393. [PMID: 38047088 PMCID: PMC10690572 DOI: 10.1016/j.isci.2023.108393] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/24/2023] [Accepted: 11/01/2023] [Indexed: 12/05/2023] Open
Abstract
Ferroptosis is a type of regulated cell death characterized by lipid peroxidation and subsequent damage to the plasma membrane. Here, we report a ferroptosis resistance mechanism involving the upregulation of TXNDC12, a thioredoxin domain-containing protein located in the endoplasmic reticulum. The inducible expression of TXNDC12 during ferroptosis in leukemia cells is inhibited by the knockdown of the transcription factor ATF4, rather than NFE2L2. Mechanistically, TXNDC12 acts to inhibit lipid peroxidation without affecting iron accumulation during ferroptosis. When TXNDC12 is overexpressed, it restores the sensitivity of ATF4-knockdown cells to ferroptosis. Moreover, TXNDC12 plays a GPX4-independent role in inhibiting lipid peroxidation. The absence of TXNDC12 enhances the tumor-suppressive effects of ferroptosis induction in both cell culture and animal models. Collectively, these findings demonstrate an endoplasmic reticulum-based anti-ferroptosis pathway in cancer cells with potential translational applications.
Collapse
Affiliation(s)
- Lanlan Tang
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Yan Yu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Wenjun Deng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jiao Liu
- DAMP Laboratory, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510150, China
| | - Yichun Wang
- Department of Critical Care Medicine, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510150, China
| | - Fanghua Ye
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Qingnan He
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| |
Collapse
|
13
|
Kalinin A, Zubkova E, Menshikov M. Integrated Stress Response (ISR) Pathway: Unraveling Its Role in Cellular Senescence. Int J Mol Sci 2023; 24:17423. [PMID: 38139251 PMCID: PMC10743681 DOI: 10.3390/ijms242417423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Cellular senescence is a complex process characterized by irreversible cell cycle arrest. Senescent cells accumulate with age, promoting disease development, yet the absence of specific markers hampers the development of selective anti-senescence drugs. The integrated stress response (ISR), an evolutionarily highly conserved signaling network activated in response to stress, globally downregulates protein translation while initiating the translation of specific protein sets including transcription factors. We propose that ISR signaling plays a central role in controlling senescence, given that senescence is considered a form of cellular stress. Exploring the intricate relationship between the ISR pathway and cellular senescence, we emphasize its potential as a regulatory mechanism in senescence and cellular metabolism. The ISR emerges as a master regulator of cellular metabolism during stress, activating autophagy and the mitochondrial unfolded protein response, crucial for maintaining mitochondrial quality and efficiency. Our review comprehensively examines ISR molecular mechanisms, focusing on ATF4-interacting partners, ISR modulators, and their impact on senescence-related conditions. By shedding light on the intricate relationship between ISR and cellular senescence, we aim to inspire future research directions and advance the development of targeted anti-senescence therapies based on ISR modulation.
Collapse
Affiliation(s)
- Alexander Kalinin
- National Medical Research Centre of Cardiology Named after Academician E.I. Chazov, 121552 Moscow, Russia; (A.K.); (E.Z.)
- Faculty of Fundamental Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Ekaterina Zubkova
- National Medical Research Centre of Cardiology Named after Academician E.I. Chazov, 121552 Moscow, Russia; (A.K.); (E.Z.)
| | - Mikhail Menshikov
- National Medical Research Centre of Cardiology Named after Academician E.I. Chazov, 121552 Moscow, Russia; (A.K.); (E.Z.)
| |
Collapse
|
14
|
Park JE, Desai H, Liboy-Lugo J, Gu S, Jowhar Z, Xu A, Floor SN. IGHMBP2 deletion suppresses translation and activates the integrated stress response. bioRxiv 2023:2023.12.11.571166. [PMID: 38168189 PMCID: PMC10760061 DOI: 10.1101/2023.12.11.571166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
IGHMBP2 is a non-essential, superfamily 1 DNA/RNA helicase that is mutated in patients with rare neuromuscular diseases SMARD1 and CMT2S. IGHMBP2 is implicated in translational and transcriptional regulation via biochemical association with ribosomal proteins, pre-rRNA processing factors, and tRNA-related species. To uncover the cellular consequences of perturbing IGHMBP2, we generated full and partial IGHMBP2 deletion K562 cell lines. Using polysome profiling and a nascent protein synthesis assay, we found that IGHMBP2 deletion modestly reduces global translation. We performed Ribo-seq and RNA-seq and identified diverse gene expression changes due to IGHMBP2 deletion, including ATF4 upregulation. With recent studies showing the ISR can contribute to tRNA metabolism-linked neuropathies, we asked whether perturbing IGHMBP2 promotes ISR activation. We generated ATF4 reporter cell lines and found IGHMBP2 knockout cells demonstrate basal, chronic ISR activation. Our work expands upon the impact of IGHMBP2 in translation and elucidates molecular mechanisms that may link mutant IGHMBP2 to severe clinical phenotypes.
Collapse
Affiliation(s)
- Jesslyn E. Park
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Hetvee Desai
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
| | - José Liboy-Lugo
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Sohyun Gu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Ziad Jowhar
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Albert Xu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Stephen N. Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California, USA, 94143
| |
Collapse
|
15
|
Hicks D, Giresh K, Wrischnik LA, Weiser DC. The PPP1R15 Family of eIF2-alpha Phosphatase Targeting Subunits (GADD34 and CReP). Int J Mol Sci 2023; 24:17321. [PMID: 38139150 PMCID: PMC10743859 DOI: 10.3390/ijms242417321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The vertebrate PPP1R15 family consists of the proteins GADD34 (growth arrest and DNA damage-inducible protein 34, the product of the PPP1R15A gene) and CReP (constitutive repressor of eIF2α phosphorylation, the product of the PPP1R15B gene), both of which function as targeting/regulatory subunits for protein phosphatase 1 (PP1) by regulating subcellular localization, modulating substrate specificity and assembling complexes with target proteins. The primary cellular function of these proteins is to facilitate the dephosphorylation of eukaryotic initiation factor 2-alpha (eIF2α) by PP1 during cell stress. In this review, we will provide a comprehensive overview of the cellular function, biochemistry and pharmacology of GADD34 and CReP, starting with a brief introduction of eIF2α phosphorylation via the integrated protein response (ISR). We discuss the roles GADD34 and CReP play as feedback inhibitors of the unfolded protein response (UPR) and highlight the critical function they serve as inhibitors of the PERK-dependent branch, which is particularly important since it can mediate cell survival or cell death, depending on how long the stressful stimuli lasts, and GADD34 and CReP play key roles in fine-tuning this cellular decision. We briefly discuss the roles of GADD34 and CReP homologs in model systems and then focus on what we have learned about their function from knockout mice and human patients, followed by a brief review of several diseases in which GADD34 and CReP have been implicated, including cancer, diabetes and especially neurodegenerative disease. Because of the potential importance of GADD34 and CReP in aspects of human health and disease, we will discuss several pharmacological inhibitors of GADD34 and/or CReP that show promise as treatments and the controversies as to their mechanism of action. This review will finish with a discussion of the biochemical properties of GADD34 and CReP, their regulation and the additional interacting partners that may provide insight into the roles these proteins may play in other cellular pathways. We will conclude with a brief outline of critical areas for future study.
Collapse
Affiliation(s)
- Danielle Hicks
- Department of Science, Mathematics and Engineering, Modesto Junior College, Modesto, CA 95350, USA
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Krithika Giresh
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Lisa A. Wrischnik
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Douglas C. Weiser
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| |
Collapse
|
16
|
Salazar-Martín AG, Kalluri AS, Villanueva MA, Hughes TK, Wadsworth MH, Dao TT, Balcells M, Nezami FR, Shalek AK, Edelman ER. Single-Cell RNA Sequencing Reveals That Adaptation of Human Aortic Endothelial Cells to Antiproliferative Therapies Is Modulated by Flow-Induced Shear Stress. Arterioscler Thromb Vasc Biol 2023; 43:2265-2281. [PMID: 37732484 PMCID: PMC10659257 DOI: 10.1161/atvbaha.123.319283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 09/07/2023] [Indexed: 09/22/2023]
Abstract
BACKGROUND Endothelial cells (ECs) are capable of quickly responding in a coordinated manner to a wide array of stresses to maintain vascular homeostasis. Loss of EC cellular adaptation may be a potential marker for cardiovascular disease and a predictor of poor response to endovascular pharmacological interventions such as drug-eluting stents. Here, we report single-cell transcriptional profiling of ECs exposed to multiple stimulus classes to evaluate EC adaptation. METHODS Human aortic ECs were costimulated with both pathophysiological flows mimicking shear stress levels found in the human aorta (laminar and turbulent, ranging from 2.5 to 30 dynes/cm2) and clinically relevant antiproliferative drugs, namely paclitaxel and rapamycin. EC state in response to these stimuli was defined using single-cell RNA sequencing. RESULTS We identified differentially expressed genes and inferred the TF (transcription factor) landscape modulated by flow shear stress using single-cell RNA sequencing. These flow-sensitive markers differentiated previously identified spatially distinct subpopulations of ECs in the murine aorta. Moreover, distinct transcriptional modules defined flow- and drug-responsive EC adaptation singly and in combination. Flow shear stress was the dominant driver of EC state, altering their response to pharmacological therapies. CONCLUSIONS We showed that flow shear stress modulates the cellular capacity of ECs to respond to paclitaxel and rapamycin administration, suggesting that while responding to different flow patterns, ECs experience an impairment in their transcriptional adaptation to other stimuli.
Collapse
Affiliation(s)
- Antonio G. Salazar-Martín
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Broad Institute of MIT and Harvard, Cambridge, MA (A.G.S.-M., M.A.V., T.T.D., A.K.S.)
| | - Aditya S. Kalluri
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
| | - Martin A. Villanueva
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Broad Institute of MIT and Harvard, Cambridge, MA (A.G.S.-M., M.A.V., T.T.D., A.K.S.)
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA (M.A.V., T.K.H., M.H.W., T.T.D., A.K.S.)
- Departments of Biology (M.A.V.), Massachusetts Institute of Technology, Cambridge
| | - Travis K. Hughes
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Koch Institute for Integrative Cancer Research (T.K.H., M.H.W., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA (M.A.V., T.K.H., M.H.W., T.T.D., A.K.S.)
- Department of Immunology, Harvard Medical School, Boston, MA (T.K.H., M.H.W., A.K.S.)
| | - Marc H. Wadsworth
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Koch Institute for Integrative Cancer Research (T.K.H., M.H.W., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA (M.A.V., T.K.H., M.H.W., T.T.D., A.K.S.)
- Department of Immunology, Harvard Medical School, Boston, MA (T.K.H., M.H.W., A.K.S.)
| | - Tyler T. Dao
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Broad Institute of MIT and Harvard, Cambridge, MA (A.G.S.-M., M.A.V., T.T.D., A.K.S.)
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA (M.A.V., T.K.H., M.H.W., T.T.D., A.K.S.)
- Biological Engineering (T.T.D.), Massachusetts Institute of Technology, Cambridge
| | - Mercedes Balcells
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
| | - Farhad R. Nezami
- Division of Cardiac Surgery (F.R.N.), Brigham and Women’s Hospital, Boston, MA
| | - Alex K. Shalek
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Koch Institute for Integrative Cancer Research (T.K.H., M.H.W., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Broad Institute of MIT and Harvard, Cambridge, MA (A.G.S.-M., M.A.V., T.T.D., A.K.S.)
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA (M.A.V., T.K.H., M.H.W., T.T.D., A.K.S.)
- Chemistry (A.K.S.), Massachusetts Institute of Technology, Cambridge
- Department of Immunology, Harvard Medical School, Boston, MA (T.K.H., M.H.W., A.K.S.)
| | - Elazer R. Edelman
- Institute for Medical Engineering and Science (A.G.S.-M., A.S.K., M.A.V., T.K.H., M.H.W., T.T.D., M.B., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Koch Institute for Integrative Cancer Research (T.K.H., M.H.W., A.K.S., E.R.E.), Massachusetts Institute of Technology (MIT), Cambridge, MA
- Division of Cardiovascular Medicine, Department of Medicine (E.R.E.), Brigham and Women’s Hospital, Boston, MA
| |
Collapse
|
17
|
Goswami B, Nag S, Ray PS. Fates and functions of RNA-binding proteins under stress. Wiley Interdiscip Rev RNA 2023:e1825. [PMID: 38014833 DOI: 10.1002/wrna.1825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/03/2023] [Accepted: 10/30/2023] [Indexed: 11/29/2023]
Abstract
Exposure to stress activates a well-orchestrated set of changes in gene expression programs that allow the cell to cope with and adapt to the stress, or undergo programmed cell death. RNA-protein interactions, mediating all aspects of post-transcriptional regulation of gene expression, play crucial roles in cellular stress responses. RNA-binding proteins (RBPs), which interact with sequence/structural elements in RNAs to control the steps of RNA metabolism, have therefore emerged as central regulators of post-transcriptional responses to stress. Following exposure to a variety of stresses, the dynamic alterations in the RNA-protein interactome enable cells to respond to intracellular or extracellular perturbations by causing changes in mRNA splicing, polyadenylation, stability, translation, and localization. As RBPs play a central role in determining the cellular proteome both qualitatively and quantitatively, it has become increasingly evident that their abundance, availability, and functions are also highly regulated in response to stress. Exposure to stress initiates a series of signaling cascades that converge on post-translational modifications (PTMs) of RBPs, resulting in changes in their subcellular localization, association with stress granules, extracellular export, proteasomal degradation, and RNA-binding activities. These alterations in the fate and function of RBPs directly impact their post-transcriptional regulatory roles in cells under stress. Adopting the ubiquitous RBP HuR as a prototype, three scenarios illustrating the changes in nuclear-cytoplasmic localization, RNA-binding activity, export and degradation of HuR in response to inflammation, genotoxic stress, and heat shock depict the complex and interlinked regulatory mechanisms that control the fate and functions of RBPs under stress. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
Collapse
Affiliation(s)
- Binita Goswami
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, West Bengal, India
| | - Sharanya Nag
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, West Bengal, India
| | - Partho Sarothi Ray
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, West Bengal, India
| |
Collapse
|
18
|
Marikawa Y, Alarcon VB. An active metabolite of the anti-COVID-19 drug molnupiravir impairs mouse preimplantation embryos at clinically relevant concentrations. Reprod Toxicol 2023; 121:108475. [PMID: 37748715 PMCID: PMC10671791 DOI: 10.1016/j.reprotox.2023.108475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/04/2023] [Accepted: 09/21/2023] [Indexed: 09/27/2023]
Abstract
Molnupiravir is a nucleoside analog antiviral that is authorized for use in the treatment of COVID-19. For its therapeutic action, molnupiravir is converted after ingestion to the active metabolite N4-hydroxycytidine, which is incorporated into the viral genome to cause lethal mutagenesis. Molnupiravir is not recommended for use during pregnancy, because preclinical animal studies suggest that it is hazardous to developing embryos. However, the mechanisms underlying the embryotoxicity of molnupiravir are currently unknown. To gain mechanistic insights into its embryotoxic action, the effects of molnupiravir and N4-hydroxycytidine were examined on the in vitro development of mouse preimplantation embryos. Molnupiravir did not prevent blastocyst formation even at concentrations that were much higher than the therapeutic plasma levels. By contrast, N4-hyroxycytidine exhibited potent toxicity, as it interfered with blastocyst formation and caused extensive cell death at concentrations below the therapeutic plasma levels. The adverse effects of N4-hydroxycytidine were dependent on the timing of exposure, such that treatment after the 8-cell stage, but not before it, caused embryotoxicity. Transcriptomic analysis of N4-hydroxycytidine-exposed embryos, together with the examination of eIF-2a protein phosphorylation level, suggested that N4-hydroxycytidine induced the integrated stress response. The adverse effects of N4-hydroxycytidine were significantly alleviated by the co-treatment with S-(4-nitrobenzyl)-6-thioinosine, suggesting that the embryotoxic potential of N4-hydroxycytidine requires the activity of nucleoside transporters. These findings show that the active metabolite of molnupiravir impairs preimplantation development at clinically relevant concentrations, providing mechanistic foundation for further studies on the embryotoxic potential of molnupiravir and other related nucleoside antivirals.
Collapse
Affiliation(s)
- Yusuke Marikawa
- Institute for Biogenesis Research, Department of Anatomy, Biochemistry and Physiology, University of Hawaii John A. Burns School of Medicine, Honolulu, HI 96813, USA
| | - Vernadeth B Alarcon
- Institute for Biogenesis Research, Department of Anatomy, Biochemistry and Physiology, University of Hawaii John A. Burns School of Medicine, Honolulu, HI 96813, USA.
| |
Collapse
|
19
|
Sayles NM, Napierala JS, Anrather J, Diedhiou N, Li J, Napierala M, Puccio H, Manfredi G. Comparative multi-omic analyses of cardiac mitochondrial stress in three mouse models of frataxin deficiency. Dis Model Mech 2023; 16:dmm050114. [PMID: 37691621 PMCID: PMC10581388 DOI: 10.1242/dmm.050114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
Cardiomyopathy is often fatal in Friedreich ataxia (FA). However, FA hearts maintain adequate function until advanced disease stages, suggesting initial adaptation to the loss of frataxin (FXN). Conditional cardiac knockout mouse models of FXN show transcriptional and metabolic profiles of the mitochondrial integrated stress response (ISRmt), which could play an adaptive role. However, the ISRmt has not been investigated in models with disease-relevant, partial decrease in FXN. We characterized the heart transcriptomes and metabolomes of three mouse models with varying degrees of FXN depletion: YG8-800, KIKO-700 and FXNG127V. Few metabolites were changed in YG8-800 mice, which did not provide a signature of cardiomyopathy or ISRmt; several metabolites were altered in FXNG127V and KIKO-700 hearts. Transcriptional changes were found in all models, but differentially expressed genes consistent with cardiomyopathy and ISRmt were only identified in FXNG127V hearts. However, these changes were surprisingly mild even at advanced age (18 months), despite a severe decrease in FXN levels to 1% of those of wild type. These findings indicate that the mouse heart has low reliance on FXN, highlighting the difficulty in modeling genetically relevant FA cardiomyopathy.
Collapse
Affiliation(s)
- Nicole M. Sayles
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY 10065, USA
- Neuroscience Graduate Program, Will Cornell Graduate School of Medical Sciences, 1300 York Ave, New York, NY 10065, USA
| | - Jill S. Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Josef Anrather
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY 10065, USA
| | - Nadège Diedhiou
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/Université de Strasbourg UMR7104, Inserm U1258, B. P. 163, 67404 Illkirch, France
| | - Jixue Li
- Department of Neurology, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hélène Puccio
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/Université de Strasbourg UMR7104, Inserm U1258, B. P. 163, 67404 Illkirch, France
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY 10065, USA
| |
Collapse
|
20
|
Hanquier Z, Misra J, Baxter R, Maiers JL. Stress and Liver Fibrogenesis: Understanding the Role and Regulation of Stress Response Pathways in Hepatic Stellate Cells. Am J Pathol 2023; 193:1363-1376. [PMID: 37422148 PMCID: PMC10548279 DOI: 10.1016/j.ajpath.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/24/2023] [Accepted: 06/06/2023] [Indexed: 07/10/2023]
Abstract
Stress response pathways are crucial for cells to adapt to physiological and pathologic conditions. Increased transcription and translation in response to stimuli place a strain on the cell, necessitating increased amino acid supply, protein production and folding, and disposal of misfolded proteins. Stress response pathways, such as the unfolded protein response (UPR) and the integrated stress response (ISR), allow cells to adapt to stress and restore homeostasis; however, their role and regulation in pathologic conditions, such as hepatic fibrogenesis, are unclear. Liver injury promotes fibrogenesis through activation of hepatic stellate cells (HSCs), which produce and secrete fibrogenic proteins to promote tissue repair. This process is exacerbated in chronic liver disease, leading to fibrosis and, if unchecked, cirrhosis. Fibrogenic HSCs exhibit activation of both the UPR and ISR, due in part to increased transcriptional and translational demands, and these stress responses play important roles in fibrogenesis. Targeting these pathways to limit fibrogenesis or promote HSC apoptosis is a potential antifibrotic strategy, but it is limited by our lack of mechanistic understanding of how the UPR and ISR regulate HSC activation and fibrogenesis. This article explores the role of the UPR and ISR in the progression of fibrogenesis, and highlights areas that require further investigation to better understand how the UPR and ISR can be targeted to limit hepatic fibrosis progression.
Collapse
Affiliation(s)
- Zachary Hanquier
- Department of Molecular and Medical Genetics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jagannath Misra
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Reese Baxter
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jessica L Maiers
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
| |
Collapse
|
21
|
Örd T, Örd D, Adler P, Örd T. Genome-wide census of ATF4 binding sites and functional profiling of trait-associated genetic variants overlapping ATF4 binding motifs. PLoS Genet 2023; 19:e1011014. [PMID: 37906604 PMCID: PMC10637723 DOI: 10.1371/journal.pgen.1011014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/10/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023] Open
Abstract
Activating Transcription Factor 4 (ATF4) is an important regulator of gene expression in stress responses and developmental processes in many cell types. Here, we catalogued ATF4 binding sites in the human genome and identified overlaps with trait-associated genetic variants. We probed these genetic variants for allelic regulatory activity using a massively parallel reporter assay (MPRA) in HepG2 hepatoma cells exposed to tunicamycin to induce endoplasmic reticulum stress and ATF4 upregulation. The results revealed that in the majority of cases, the MPRA allelic activity of these SNPs was in agreement with the nucleotide preference seen in the ATF4 binding motif from ChIP-Seq. Luciferase and electrophoretic mobility shift assays in additional cellular models further confirmed ATF4-dependent regulatory effects for the SNPs rs532446 (GADD45A intronic; linked to hematological parameters), rs7011846 (LPL upstream; myocardial infarction), rs2718215 (diastolic blood pressure), rs281758 (psychiatric disorders) and rs6491544 (educational attainment). CRISPR-Cas9 disruption and/or deletion of the regulatory elements harboring rs532446 and rs7011846 led to the downregulation of GADD45A and LPL, respectively. Thus, these SNPs could represent examples of GWAS genetic variants that affect gene expression by altering ATF4-mediated transcriptional activation.
Collapse
Affiliation(s)
- Tiit Örd
- Institute of Genomics, University of Tartu, Tartu, Estonia
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Daima Örd
- Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Priit Adler
- Institute of Computer Science, University of Tartu, Tartu, Estonia
| | - Tõnis Örd
- Institute of Genomics, University of Tartu, Tartu, Estonia
| |
Collapse
|
22
|
Das B, Samal S, Hamdi H, Pal A, Biswas A, Behera J, Singh G, Behera CK, Sahoo DP, Pati S. Role of endoplasmic reticulum stress-related unfolded protein response and its implications in dengue virus infection for biomarker development. Life Sci 2023; 329:121982. [PMID: 37517582 DOI: 10.1016/j.lfs.2023.121982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023]
Abstract
Dengue virus (DENV) causes debilitating disease in humans, which varies at different rates in host cells, such as monocytes, macrophages, dendritic cells, Langerhans cells, and other cell types. Such heterogeneity in DENV infection in cells could be attributed to a range of factors, including host cell immune response, anti-viral cellular proteins, and virus mediated cellular autophagy. This review delineates an important feature of every cell, the unfolded protein response (UPR) that is attributed to the accumulation of several viral and unfolded/misfolded proteins, such as in DENV infection. UPR is a normal process to counteract endoplasmic reticulum (ER) stress that leads to cell autophagy; though the phenomenon is markedly upregulated during DENV infection. This could be attributed to the uncontrolled activation of the key UPR signaling pathways: inositol-requiring transmembrane kinase/endoribonuclease 1 (IRE1), protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), and activating transcription factor-6 (ATF6), which promote cell autophagy under normal and diseased conditions through the downstream regulation of apoptosis promoting factors such as X-box binding protein (XBP1), GADD34, and ATF-6. Because DENV can modulate these signaling cascades, by promoting dysregulated cell autophagy, the ER stress mediated UPR pathways and the inherent agents could play an important role in delineating the severity of dengue infection with a potential for developing DENV targeted therapeutics.
Collapse
Affiliation(s)
- Biswadeep Das
- School of Biotechnology, Kalinga Institute of Industrial Technology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024, India.
| | - Sagnika Samal
- School of Biotechnology, Kalinga Institute of Industrial Technology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024, India
| | - Hamida Hamdi
- Zoology Department, Faculty of Science, Cairo University, Giza 12613, Egypt; Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
| | - Aditi Pal
- School of Biotechnology, Kalinga Institute of Industrial Technology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024, India
| | - Arpita Biswas
- School of Biotechnology, Kalinga Institute of Industrial Technology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024, India
| | - Jyotika Behera
- School of Biotechnology, Kalinga Institute of Industrial Technology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024, India
| | - Gyanraj Singh
- Department of Anatomy, Kalinga Institute of Medical Sciences, KIIT-DU, Bhubaneswar, Odisha 751024, India
| | - Chinmay Kumar Behera
- Department of Pediatrics, Kalinga Institute of Medical Sciences, KIIT-DU, Bhubaneswar, Odisha 751024, India
| | - Debee Prasad Sahoo
- School of Biotechnology, Kalinga Institute of Industrial Technology, KIIT Deemed to Be University, Bhubaneswar, Odisha 751024, India
| | - Sanghamitra Pati
- Regional Medical Research Centre-ICMR, Nalco Square, Bhubaneswar, Odisha 751023, India
| |
Collapse
|
23
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
Affiliation(s)
| | | | | | - Crystal S. Conn
- Department of Radiation Oncology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| |
Collapse
|
24
|
Sagar S, Gustafsson AB. Cardiovascular aging: the mitochondrial influence. J Cardiovasc Aging 2023; 3:33. [PMID: 37583788 PMCID: PMC10426788 DOI: 10.20517/jca.2023.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Age-associated cardiovascular disease is becoming progressively prevalent due to the increased lifespan of the population. However, the fundamental mechanisms underlying the aging process and the corresponding decline in tissue functions are still poorly understood. The heart has a very high energy demand and the cellular energy needed to sustain contraction is primarily generated by mitochondrial oxidative phosphorylation. Mitochondria are also involved in supporting various metabolic processes, as well as activation of the innate immune response and cell death pathways. Given the central role of mitochondria in energy metabolism and cell survival, the heart is highly susceptible to the effects of mitochondrial dysfunction. These key organelles have been implicated as underlying drivers of cardiac aging. Here, we review the evidence demonstrating the mitochondrial contribution to the cardiac aging process and disease susceptibility. We also discuss the potential mechanisms responsible for the age-related decline in mitochondrial function.
Collapse
Affiliation(s)
- Shakti Sagar
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Asa B Gustafsson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
25
|
Guo H, Zhang S, Zhang B, Shang Y, Liu X, Wang M, Wang H, Fan Y, Tan K. Immunogenic landscape and risk score prediction based on unfolded protein response (UPR)-related molecular subtypes in hepatocellular carcinoma. Front Immunol 2023; 14:1202324. [PMID: 37457742 PMCID: PMC10348016 DOI: 10.3389/fimmu.2023.1202324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023] Open
Abstract
Background Hepatocellular carcinoma (HCC) is the most common type of cancer and causes a significant number of cancer-related deaths worldwide. The molecular mechanisms underlying the development of HCC are complex, and the heterogeneity of HCC has led to a lack of effective prognostic indicators and drug targets for clinical treatment of HCC. Previous studies have indicated that the unfolded protein response (UPR), a fundamental pathway for maintaining endoplasmic reticulum homeostasis, is involved in the formation of malignant characteristics such as tumor cell invasiveness and treatment resistance. The aims of our study are to identify new prognostic indicators and provide drug treatment targets for HCC in clinical treatment based on UPR-related genes (URGs). Methods Gene expression profiles and clinical information were downloaded from the TCGA, ICGC and GEO databases. Consensus cluster analysis was performed to classify the molecular subtypes of URGs in HCC patients. Univariate Cox regression and machine learning LASSO algorithm were used to establish a risk prognosis model. Kaplan-Meier and ROC analyses were used to evaluate the clinical prognosis of URGs. TIMER and XCell algorithms were applied to analyze the relationships between URGs and immune cell infiltration. Real time-PCR was performed to analyze the effect of sorafenib on the expression levels of four URGs. Results Most URGs were upregulated in HCC samples. According to the expression pattern of URGs, HCC patients were divided into two independent clusters. Cluster 1 had a higher expression level, worse prognosis, and higher expression of immunosuppressive factors than cluster 2. Patients in cluster 1 were more prone to immune escape during immunotherapy, and were more sensitive to chemotherapeutic drugs. Four key UPR genes (ATF4, GOSR2, PDIA6 and SRPRB) were established in the prognostic model and HCC patients with high risk score had a worse clinical prognosis. Additionally, patients with high expression of four URGs are more sensitive to sorafenib. Moreover, ATF4 was upregulated, while GOSR2, PDIA6 and SRPRB were downregulated in sorafenib-treated HCC cells. Conclusion The UPR-related prognostic signature containing four URGs exhibits high potential application value and performs well in the evaluation of effects of chemotherapy/immunotherapy and clinical prognosis.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Yumei Fan
- *Correspondence: Yumei Fan, ; Ke Tan,
| | - Ke Tan
- *Correspondence: Yumei Fan, ; Ke Tan,
| |
Collapse
|