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Ingelson-Filpula WA, Kadamani KL, Ojaghi M, Pamenter ME, Storey KB. Hypoxia-induced downregulation of RNA m 6A protein machinery in the naked mole-rat heart. Biochimie 2024; 225:125-132. [PMID: 38788827 DOI: 10.1016/j.biochi.2024.05.017] [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: 02/22/2024] [Revised: 05/15/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024]
Abstract
Naked mole-rats, Heterocephalus glaber, are champion hypoxia-tolerant rodents that live under low oxygen conditions in their subterranean burrows. Detrimental effects of low oxygen can be mitigated through metabolic rate depression (MRD), metabolic reorganization, and global downregulation of nonessential cellular processes. Recent research has progressively implicated epigenetic modifications - rapid, reversible changes to gene expression that do not alter the DNA sequence itself - as major players in implementing and maintaining MRD. N6-adenosine (m6A) methylation is the most prevalent mammalian RNA modification and is responsible for pre-mRNA processing and mRNA export from the nucleus. Hence, m6A -mediated conformational changes alter the cellular fate of transcripts. The present study investigated the role of m6A RNA methylation responses to 24 h of hypoxia exposure in H. glaber cardiac tissue. Total protein levels of m6A writers/readers/erasers, m6A demethylase activity, and total m6A quantification were measured under normoxic vs. hypoxic conditions in H. glaber heart. While there was no change in either demethylase activity or total m6A content, many proteins of the m6A pathway were downregulated during hypoxia. Overall, m6A may not be a signature hypoxia-responsive characteristic in H. glaber heart, but downregulation of the protein machinery involved in m6A cycling points to an alternate biological involvement. Further research will explore other forms of RNA modifications and other epigenetic mechanisms to determine the controls on hypoxia endurance in this subterranean mammal.
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Affiliation(s)
- W Aline Ingelson-Filpula
- Affiliation: Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada, K1S 5B6.
| | - Karen L Kadamani
- Biology Department, University of Ottawa, Marie-Curie Pvt, Ottawa, Ontario, K1N 9A7, Canada
| | - Mohammad Ojaghi
- Biology Department, University of Ottawa, Marie-Curie Pvt, Ottawa, Ontario, K1N 9A7, Canada
| | - Matthew E Pamenter
- Biology Department, University of Ottawa, Marie-Curie Pvt, Ottawa, Ontario, K1N 9A7, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Kenneth B Storey
- Affiliation: Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada, K1S 5B6
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Zhang D, Tao J, Zhang X, Ma X, Li C, Li H, Li W, Chen J, Liu H. Novel Pro-myogenic Factor Neoruscogenin Induces Muscle Fiber Hypertrophy by Inhibiting MSTN Maturation and Activating the Akt/mTOR Pathway. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:499-511. [PMID: 36563293 DOI: 10.1021/acs.jafc.2c06527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Neoruscogenin is a plant-origin sapogenin that has the potential to modulate muscle growth among the small-molecule compounds that we previously predicted by artificial intelligence to target myostatin (MSTN). This study aimed to elucidate the biological role of neoruscogenin on muscle growth and its relationship with MSTN. Using molecular biological techniques, we found that neoruscogenin inhibited MSTN maturation, thereby repressing its signal transduction; further facilitated protein synthesis metabolism and reduced protein degradation metabolism, ultimately promoting the differentiation of myoblasts and hypertrophy of muscle fibers; and had the effect of repairing muscle injury. This study enriched the biological functions of neoruscogenin and provided a theoretical basis for the treatment of human myopathy and its application in the livestock industry.
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Affiliation(s)
- Dingding Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Jingli Tao
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xuan Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiangfei Ma
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Chengyu Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongmin Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Weijian Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Jie Chen
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Honglin Liu
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
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Ingelson-Filpula WA, Cheng H, Eaton L, Pamenter ME, Storey KB. Small RNA sequencing in hypoxic naked mole-rat hearts suggests microRNA regulation of RNA- and translation-related processes. FEBS Lett 2022; 596:2821-2833. [PMID: 36120811 DOI: 10.1002/1873-3468.14499] [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: 08/25/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/09/2022]
Abstract
The naked mole-rat (Heterocephalus glaber) regularly endures intermittent periods of hypoxia in its burrows, surviving in part due to metabolic rate depression (MRD)-a strategy of conserving cellular resources by downregulating nonessential gene expression and reorganizing cellular processes. MicroRNA (miRNA) are short, noncoding RNAs already implicated for their roles in numerous models of extreme environmental stress; given their rapid, reversible nature, they are ideal for implementing MRD. We performed small RNA sequencing on cardiac tissue from normoxic vs. 24 h hypoxic naked mole-rats, and used bioinformatics to predict eighteen miRNAs which may be differentially regulated during hypoxia. Gene Ontology and KEGG pathway mapping further suggest these miRNAs play roles in largely translation-related functions, including RNA processing and catabolism.
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Affiliation(s)
- W Aline Ingelson-Filpula
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Hang Cheng
- Biology Department, University of Ottawa, Marie-Curie Pvt, Ottawa, Ontario, K1N 9A7, Canada
| | - Liam Eaton
- Biology Department, University of Ottawa, Marie-Curie Pvt, Ottawa, Ontario, K1N 9A7, Canada
| | - Matthew E Pamenter
- Biology Department, University of Ottawa, Marie-Curie Pvt, Ottawa, Ontario, K1N 9A7, Canada.,Brain and Mind Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
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Sjodin BMF, Russello MA. Comparative genomics reveals putative evidence for high-elevation adaptation in the American pika ( Ochotona princeps). G3 GENES|GENOMES|GENETICS 2022; 12:6695220. [PMID: 36087005 PMCID: PMC9635661 DOI: 10.1093/g3journal/jkac241] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022]
Abstract
High-elevation environments have lower atmospheric oxygen content, reduced temperatures, and higher levels of UV radiation than found at lower elevations. As such, species living at high elevations must overcome these challenges to survive, grow, and reproduce. American pikas (Ochotona princeps) are alpine lagomorphs that are habitat specialists typically found at elevations >2,000 m. Previous research has shown putative evidence for high-elevation adaptation; however, investigations to date have been limited to a fraction of the genome. Here, we took a comparative genomics approach to identify putative regions under selection using a chromosomal reference genome assembly for the American pika relative to 8 other mammalian species targeted based on phylogenetic relatedness and (dis)similarity in ecology. We first identified orthologous gene groups across species and then extracted groups containing only American pika genes as well as unclustered pika genes to inform functional enrichment analyses; among these, we found 141 enriched terms with many related to hypoxia, metabolism, mitochondrial function/development, and DNA repair. We identified 15 significantly expanded gene families within the American pika across all orthologous gene groups that displayed functionally enriched terms associated with hypoxia adaptation. We further detected 196 positively selected genes, 41 of which have been associated with putative adaptation to hypoxia, cold tolerance, and response to UV following a literature review. In particular, OXNAD1, NRDC, and those genes critical in DNA repair represent important targets for future research to examine their functional implications in the American pika, especially as they may relate to adaptation to rapidly changing environments.
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Affiliation(s)
- Bryson M F Sjodin
- Department of Biology, University of British Columbia, Okanagan Campus , Kelowna, V1V 1V7 BC, Canada
| | - Michael A Russello
- Department of Biology, University of British Columbia, Okanagan Campus , Kelowna, V1V 1V7 BC, Canada
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D’Alessio S, Cheng H, Eaton L, Kraev I, Pamenter ME, Lange S. Acute Hypoxia Alters Extracellular Vesicle Signatures and the Brain Citrullinome of Naked Mole-Rats (Heterocephalus glaber). Int J Mol Sci 2022; 23:ijms23094683. [PMID: 35563075 PMCID: PMC9100269 DOI: 10.3390/ijms23094683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/20/2022] [Accepted: 04/22/2022] [Indexed: 02/04/2023] Open
Abstract
Peptidylarginine deiminases (PADs) and extracellular vesicles (EVs) may be indicative biomarkers of physiological and pathological status and adaptive responses, including to diseases and disorders of the central nervous system (CNS) and related to hypoxia. While these markers have been studied in hypoxia-intolerant mammals, in vivo investigations in hypoxia-tolerant species are lacking. Naked mole-rats (NMR) are among the most hypoxia-tolerant mammals and are thus a good model organism for understanding natural and beneficial adaptations to hypoxia. Thus, we aimed to reveal CNS related roles for PADs in hypoxia tolerance and identify whether circulating EV signatures may reveal a fingerprint for adaptive whole-body hypoxia responses in this species. We found that following in vivo acute hypoxia, NMR: (1) plasma-EVs were remodelled, (2) whole proteome EV cargo contained more protein hits (including citrullinated proteins) and a higher number of associated KEGG pathways relating to the total proteome of plasma-EVs Also, (3) brains had a trend for elevation in PAD1, PAD3 and PAD6 protein expression, while PAD2 and PAD4 were reduced, while (4) the brain citrullinome had a considerable increase in deiminated protein hits with hypoxia (1222 vs. 852 hits in normoxia). Our findings indicate that circulating EV signatures are modified and proteomic content is reduced in hypoxic conditions in naked mole-rats, including the circulating EV citrullinome, while the brain citrullinome is elevated and modulated in response to hypoxia. This was further reflected in elevation of some PADs in the brain tissue following acute hypoxia treatment. These findings indicate a possible selective role for PAD-isozymes in hypoxia response and tolerance.
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Affiliation(s)
- Stefania D’Alessio
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London W1W 6 UW, UK;
| | - Hang Cheng
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (H.C.); (L.E.); (M.E.P.)
| | - Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (H.C.); (L.E.); (M.E.P.)
| | - Igor Kraev
- Electron Microscopy Suite, Faculty of Science, Technology, Engineering and Mathematics, Open University, Walton Hall, Milton Keynes MK7 6AA, UK;
| | - Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (H.C.); (L.E.); (M.E.P.)
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Sigrun Lange
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London W1W 6 UW, UK;
- Correspondence: ; Tel.: +44-(0)-20-7911-5000 (ext. 64832)
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Farhat E, Talarico GGM, Grégoire M, Weber JM, Mennigen JA. Epigenetic and post-transcriptional repression support metabolic suppression in chronically hypoxic goldfish. Sci Rep 2022; 12:5576. [PMID: 35368037 PMCID: PMC8976842 DOI: 10.1038/s41598-022-09374-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/21/2022] [Indexed: 12/03/2022] Open
Abstract
Goldfish enter a hypometabolic state to survive chronic hypoxia. We recently described tissue-specific contributions of membrane lipid composition remodeling and mitochondrial function to metabolic suppression across different goldfish tissues. However, the molecular and especially epigenetic foundations of hypoxia tolerance in goldfish under metabolic suppression are not well understood. Here we show that components of the molecular oxygen-sensing machinery are robustly activated across tissues irrespective of hypoxia duration. Induction of gene expression of enzymes involved in DNA methylation turnover and microRNA biogenesis suggest a role for epigenetic transcriptional and post-transcriptional suppression of gene expression in the hypoxia-acclimated brain. Conversely, mechanistic target of rapamycin-dependent translational machinery activity is not reduced in liver and white muscle, suggesting this pathway does not contribute to lowering cellular energy expenditure. Finally, molecular evidence supports previously reported chronic hypoxia-dependent changes in membrane cholesterol, lipid metabolism and mitochondrial function via changes in transcripts involved in cholesterol biosynthesis, β-oxidation, and mitochondrial fusion in multiple tissues. Overall, this study shows that chronic hypoxia robustly induces expression of oxygen-sensing machinery across tissues, induces repressive transcriptional and post-transcriptional epigenetic marks especially in the chronic hypoxia-acclimated brain and supports a role for membrane remodeling and mitochondrial function and dynamics in promoting metabolic suppression.
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Affiliation(s)
- Elie Farhat
- Department of Biology, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5, Canada
| | - Giancarlo G M Talarico
- Department of Biology, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5, Canada
| | - Mélissa Grégoire
- Department of Biology, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5, Canada
| | - Jean-Michel Weber
- Department of Biology, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5, Canada
| | - Jan A Mennigen
- Department of Biology, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
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Abstract
ABSTRACT
Hypoxia is one of the strongest environmental drivers of cellular and physiological adaptation. Although most mammals are largely intolerant of hypoxia, some specialized species have evolved mitigative strategies to tolerate hypoxic niches. Among the most hypoxia-tolerant mammals are naked mole-rats (Heterocephalus glaber), a eusocial species of subterranean rodent native to eastern Africa. In hypoxia, naked mole-rats maintain consciousness and remain active despite a robust and rapid suppression of metabolic rate, which is mediated by numerous behavioural, physiological and cellular strategies. Conversely, hypoxia-intolerant mammals and most other hypoxia-tolerant mammals cannot achieve the same degree of metabolic savings while staying active in hypoxia and must also increase oxygen supply to tissues, and/or enter torpor. Intriguingly, recent studies suggest that naked mole-rats share many cellular strategies with non-mammalian vertebrate champions of anoxia tolerance, including the use of alternative metabolic end-products and potent pH buffering mechanisms to mitigate cellular acidification due to upregulation of anaerobic metabolic pathways, rapid mitochondrial remodelling to favour increased respiratory efficiency, and systemic shifts in energy prioritization to maintain brain function over that of other tissues. Herein, I discuss what is known regarding adaptations of naked mole-rats to a hypoxic lifestyle, and contrast strategies employed by this species to those of hypoxia-intolerant mammals, closely related African mole-rats, other well-studied hypoxia-tolerant mammals, and non-mammalian vertebrate champions of anoxia tolerance. I also discuss the neotenic theory of hypoxia tolerance – a leading theory that may explain the evolutionary origins of hypoxia tolerance in mammals – and highlight promising but underexplored avenues of hypoxia-related research in this fascinating model organism.
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Affiliation(s)
- Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 9A7. University of Ottawa, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada, K1H 8M5
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Chacón-Aponte AA, Durán-Vargas ÉA, Arévalo-Carrillo JA, Lozada-Martínez ID, Bolaño-Romero MP, Moscote-Salazar LR, Grille P, Janjua T. Brain-lung interaction: a vicious cycle in traumatic brain injury. Acute Crit Care 2022; 37:35-44. [PMID: 35172526 PMCID: PMC8918716 DOI: 10.4266/acc.2021.01193] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 11/30/2022] Open
Abstract
The brain-lung interaction can seriously affect patients with traumatic brain injury, triggering a vicious cycle that worsens patient prognosis. Although the mechanisms of the interaction are not fully elucidated, several hypotheses, notably the "blast injury" theory or "double hit" model, have been proposed and constitute the basis of its development and progression. The brain and lungs strongly interact via complex pathways from the brain to the lungs but also from the lungs to the brain. The main pulmonary disorders that occur after brain injuries are neurogenic pulmonary edema, acute respiratory distress syndrome, and ventilator-associated pneumonia, and the principal brain disorders after lung injuries include brain hypoxia and intracranial hypertension. All of these conditions are key considerations for management therapies after traumatic brain injury and need exceptional case-by-case monitoring to avoid neurological or pulmonary complications. This review aims to describe the history, pathophysiology, risk factors, characteristics, and complications of brain-lung and lung-brain interactions and the impact of different old and recent modalities of treatment in the context of traumatic brain injury.
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Affiliation(s)
| | | | | | - Iván David Lozada-Martínez
- Colombian Clinical Research Group in Neurocritical Care, University of Cartagena, Cartagena, Colombia
- Latin American Council of Neurocritical Care (CLaNi), Cartagena, Colombia
- Global Neurosurgery Committee, World Federation of Neurosurgical Societies, Cartagena, Colombia
- Medical and Surgical Research Center, Cartagena, Colombia
| | | | - Luis Rafael Moscote-Salazar
- Colombian Clinical Research Group in Neurocritical Care, University of Cartagena, Cartagena, Colombia
- Latin American Council of Neurocritical Care (CLaNi), Cartagena, Colombia
- Medical and Surgical Research Center, Cartagena, Colombia
| | - Pedro Grille
- Department of Intensive Care, Hospital Maciel, Montevideo, Uruguay
| | - Tariq Janjua
- Department of Intensive Care, Regions Hospital, St. Paul, MN, USA
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Pamenter ME, Cheng H. Supermole-rat to the rescue: Does the naked mole-rat offer a panacea for all that ails us? Comp Biochem Physiol A Mol Integr Physiol 2022; 266:111139. [PMID: 34990825 DOI: 10.1016/j.cbpa.2021.111139] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/21/2021] [Accepted: 12/28/2021] [Indexed: 11/16/2022]
Abstract
Over the previous several decades, many non-traditional research models have offered new avenues of exploration for biomedical research. The promise of these animals is primarily derived from adaptations to unique or challenging environments that share key factors with a disease or pathology of interest (e.g., hypoxemia or hypercarbia are clinically relevant and are also in vivo consequences of environmental hypoxia and hypercapnia, respectively). Animals adapted to such environments allow us to ask the question: how has nature solved a particular problem and what can we learn to inform novel translational research into the treatment of related diseases and pathologies? One of the most promising mammalian models that have garnered increasing attention from researchers and the public are naked mole-rats (NMRs). The NMR is a small and eusocial subterranean rodent species that live in a putatively hypoxic and hypercapnic burrow environment. Intriguingly, whereas most non-traditional biomedical models offer insight into one or only a few diseases related to a common physiological stress, NMRs in contrast have proven to be resistant to a very wide range of ailments, including aging, cancer, and hypoxia- and hypercapnia-related disorders, among many others. In the present commentary, we discuss progress made in understanding how NMRs overcome these challenges and speculate on the origins of their remarkable abilities.
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Affiliation(s)
- Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
| | - Hang Cheng
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
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Wu CW, Storey KB. mTOR Signaling in Metabolic Stress Adaptation. Biomolecules 2021; 11:biom11050681. [PMID: 34062764 PMCID: PMC8147357 DOI: 10.3390/biom11050681] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 12/30/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a central regulator of cellular homeostasis that integrates environmental and nutrient signals to control cell growth and survival. Over the past two decades, extensive studies of mTOR have implicated the importance of this protein complex in regulating a broad range of metabolic functions, as well as its role in the progression of various human diseases. Recently, mTOR has emerged as a key signaling molecule in regulating animal entry into a hypometabolic state as a survival strategy in response to environmental stress. Here, we review current knowledge of the role that mTOR plays in contributing to natural hypometabolic states such as hibernation, estivation, hypoxia/anoxia tolerance, and dauer diapause. Studies across a diverse range of animal species reveal that mTOR exhibits unique regulatory patterns in an environmental stressor-dependent manner. We discuss how key signaling proteins within the mTOR signaling pathways are regulated in different animal models of stress, and describe how each of these regulations uniquely contribute to promoting animal survival in a hypometabolic state.
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Affiliation(s)
- Cheng-Wei Wu
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
- Correspondence:
| | - Kenneth B. Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada;
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11
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Hadj-Moussa H, Pamenter ME, Storey KB. Hypoxic naked mole-rat brains use microRNA to coordinate hypometabolic fuels and neuroprotective defenses. J Cell Physiol 2020; 236:5080-5097. [PMID: 33305831 DOI: 10.1002/jcp.30216] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/19/2020] [Accepted: 12/01/2020] [Indexed: 12/26/2022]
Abstract
Naked mole-rats are among the mammalian champions of hypoxia tolerance. They evolved adaptations centered around reducing metabolic rate to overcome the challenges experienced in their underground burrows. In this study, we used next-generation sequencing to investigate one of the factors likely supporting hypoxia tolerance in naked mole-rat brains, posttranscriptional microRNAs (miRNAs). Of the 212 conserved miRNAs identified using small RNA sequencing, 18 displayed significant differential expression during hypoxia. Bioinformatic enrichment revealed that hypoxia-mediated miRNAs were suppressing energy expensive processes including de novo protein translation and cellular proliferation. This suppression occurred alongside the activation of neuroprotective and neuroinflammatory pathways, and the induction of central signal transduction pathways including HIF-1α and NFκB via miR-335, miR-101, and miR-155. MiRNAs also coordinated anaerobic glycolytic fuel sources, where hypoxia-upregulated miR-365 likely suppressed protein levels of ketohexokinase, the enzyme responsible for catalyzing the first committed step of fructose catabolism. This was further supported by a hypoxia-mediated reduction in glucose transporter 5 proteins that import fructose into the cell. Yet, messenger RNA and protein levels of lactate dehydrogenase, which converts pyruvate to lactate in the absence of oxygen, were elevated during hypoxia. Together, this demonstrated the induction of anaerobic glycolysis despite a lack of reliance on fructose as the primary fuel source, suggesting that hypoxic brains are metabolically different than anoxic naked mole-rat brains that were previously found to shift to fructose-based glycolysis. Our findings contribute to the growing body of oxygen-responsive miRNAs "OxymiRs" that facilitate natural miRNA-mediated mechanisms for successful hypoxic exposures.
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Affiliation(s)
| | - Matthew E Pamenter
- Biology Department, University of Ottawa, Ottawa, Ontario, Canada.,Brain and Mind Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Kenneth B Storey
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
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Vasquez MC, Joyner-Matos J, Vázquez-Medina JP, Zenteno-Savín T, Freitas R. Oxidative stress in aquatic ecosystems: Integrated responses to multiple stressors and preparation for oxidative stress. Selected papers from the 3rd international conference. Comp Biochem Physiol A Mol Integr Physiol 2020; 249:110770. [DOI: 10.1016/j.cbpa.2020.110770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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13
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Translational control in the naked mole-rat as a model highly resistant to cancer. Biochim Biophys Acta Rev Cancer 2020; 1875:188455. [PMID: 33148499 DOI: 10.1016/j.bbcan.2020.188455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/23/2020] [Accepted: 10/15/2020] [Indexed: 12/24/2022]
Abstract
Dysregulation of mRNA translation is involved in the onset and progression of different types of cancer. To gain insight into novel genetic strategies to avoid this malady, we reviewed the available genomic, transcriptomic, and proteomic data about the translational machinery from the naked-mole rat (NMR) Heterocephalus glaber, a new model of study that exhibits high resistance to cancer. The principal features that might confer cancer resistance are 28S rRNA fragmentation, RPL26 and eIF4G overexpression, global downregulation of mTOR pathway, specific amino acid residues in RAPTOR (P908) and RICTOR (V1695), and the absence of 4E-BP3. These features are not only associated with cancer but also might couple longevity and adaptation to hypoxia. We propose that the regulation of translation is among the strategies endowing NMR cancer resistance.
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