1
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Ojaghi M, Pamenter ME. Hypoxia impairs blood glucose homeostasis in naked mole-rat adult subordinates but not queens. J Exp Biol 2024; 227:jeb247537. [PMID: 38680085 DOI: 10.1242/jeb.247537] [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: 02/16/2024] [Accepted: 04/12/2024] [Indexed: 05/01/2024]
Abstract
Naked mole-rats (NMRs) are among the most hypoxia-tolerant mammals and metabolize only carbohydrates in hypoxia. Glucose is the primary building block of dietary carbohydrates, but how blood glucose is regulated during hypoxia has not been explored in NMRs. We hypothesized that NMRs mobilize glucose stores to support anaerobic energy metabolism in hypoxia. To test this, we treated newborn, juvenile and adult (subordinate and queen) NMRs in normoxia (21% O2) or hypoxia (7, 5 or 3% O2), while measuring metabolic rate, body temperature and blood [glucose]. We also challenged animals with glucose, insulin or insulin-like growth factor-1 (IGF-1) injections and measured the rate of glucose clearance in normoxia and hypoxia. We found that: (1) blood [glucose] increases in moderate hypoxia in queens and pups, but only in severe hypoxia in adult subordinates and juveniles; (2) glucose tolerance is similar between developmental stages in normoxia, but glucose clearance times are 2- to 3-fold longer in juveniles and subordinates than in queens or pups in hypoxia; and (3) reoxygenation accelerates glucose clearance in hypoxic subordinate adults. Mechanistically, (4) insulin and IGF-1 reduce blood [glucose] in subordinates in both normoxia but only IGF-1 impacts blood [glucose] in hypoxic queens. Our results indicate that insulin signaling is impaired by hypoxia in NMRs, but that queens utilize IGF-1 to overcome this limitation and effectively regulate blood glucose in hypoxia. This suggests that sexual maturation impacts blood glucose handling in hypoxic NMR queens, which may allow queens to spend longer periods of time in hypoxic nest chambers.
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Affiliation(s)
- Mohammad Ojaghi
- Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 9A7
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 9A7
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada, K1H 8M5
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2
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Niimura Y, Biswa BB, Kishida T, Toyoda A, Fujiwara K, Ito M, Touhara K, Inoue-Murayama M, Jenkins SH, Adenyo C, Kayang BB, Koide T. Synchronized Expansion and Contraction of Olfactory, Vomeronasal, and Taste Receptor Gene Families in Hystricomorph Rodents. Mol Biol Evol 2024; 41:msae071. [PMID: 38649162 PMCID: PMC11035023 DOI: 10.1093/molbev/msae071] [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: 02/02/2023] [Revised: 02/02/2024] [Accepted: 03/03/2024] [Indexed: 04/25/2024] Open
Abstract
Chemical senses, including olfaction, pheromones, and taste, are crucial for the survival of most animals. There has long been a debate about whether different types of senses might influence each other. For instance, primates with a strong sense of vision are thought to have weakened olfactory abilities, although the oversimplified trade-off theory is now being questioned. It is uncertain whether such interactions between different chemical senses occur during evolution. To address this question, we examined four receptor gene families related to olfaction, pheromones, and taste: olfactory receptor (OR), vomeronasal receptor type 1 and type 2 (V1R and V2R), and bitter taste receptor (T2R) genes in Hystricomorpha, which is morphologically and ecologically the most diverse group of rodents. We also sequenced and assembled the genome of the grasscutter, Thryonomys swinderianus. By examining 16 available genome assemblies alongside the grasscutter genome, we identified orthologous gene groups among hystricomorph rodents for these gene families to separate the gene gain and loss events in each phylogenetic branch of the Hystricomorpha evolutionary tree. Our analysis revealed that the expansion or contraction of the four gene families occurred synchronously, indicating that when one chemical sense develops or deteriorates, the others follow suit. The results also showed that V1R/V2R genes underwent the fastest evolution, followed by OR genes, and T2R genes were the most evolutionarily stable. This variation likely reflects the difference in ligands of V1R/V2Rs, ORs, and T2Rs: species-specific pheromones, environment-based scents, and toxic substances common to many animals, respectively.
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Affiliation(s)
- Yoshihito Niimura
- Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Bhim B Biswa
- Mouse Genomics Resource Laboratory, National Institute of Genetics, Mishima, Japan
- Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), Shizuoka, Japan
| | - Takushi Kishida
- Curatorial Division, Museum of Natural and Environmental History, Shizuoka, Japan
- Present address: College of Bioresource Sciences, Nihon University, Fujisawa, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Shizuoka, Japan
| | - Kazumichi Fujiwara
- Mouse Genomics Resource Laboratory, National Institute of Genetics, Mishima, Japan
| | - Masato Ito
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kazushige Touhara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | | | - Scott H Jenkins
- Wildlife Research Center, Kyoto University, Kyoto, Japan
- Present address: Biosphere Informatics Laboratory, Department of Social Informatics, Graduate School of Informatics, Kyoto, Japan
| | - Christopher Adenyo
- Livestock and Poultry Research Centre, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Boniface B Kayang
- Department of Animal Science, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Tsuyoshi Koide
- Mouse Genomics Resource Laboratory, National Institute of Genetics, Mishima, Japan
- Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), Shizuoka, Japan
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3
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Kadamani KL, Logan SM, Pamenter ME. Does hypometabolism constrain innate immune defense? Acta Physiol (Oxf) 2024; 240:e14091. [PMID: 38288574 DOI: 10.1111/apha.14091] [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: 01/08/2023] [Revised: 11/30/2023] [Accepted: 01/01/2024] [Indexed: 02/24/2024]
Abstract
Many animals routinely make energetic trade-offs to adjust to environmental demands and these trade-offs often have significant implications for survival. For example, environmental hypoxia is commonly experienced by many organisms and is an energetically challenging condition because reduced oxygen availability constrains aerobic energy production, which can be lethal. Many hypoxia-tolerant species downregulate metabolic demands when oxygen is limited; however, certain physiological functions are obligatory and must be maintained despite the need to conserve energy in hypoxia. Of particular interest is immunity (including both constitutive and induced immune functions) because mounting an immune response is among the most energetically expensive physiological processes but maintaining immune function is critical for survival in most environments. Intriguingly, physiological responses to hypoxia and pathogens share key molecular regulators such as hypoxia-inducible factor-1α, through which hypoxia can directly activate an immune response. This raises an interesting question: do hypoxia-tolerant species mount an immune response during periods of hypoxia-induced hypometabolism? Unfortunately, surprisingly few studies have examined interactions between immunity and hypometabolism in such species. Therefore, in this review, we consider mechanistic interactions between metabolism and immunity, as well as energetic trade-offs between these two systems, in hypoxia-tolerant animals but also in other models of hypometabolism, including neonates and hibernators. Specifically, we explore the hypothesis that such species have blunted immune responses in hypometabolic conditions and/or use alternative immune pathways when in a hypometabolic state. Evidence to date suggests that hypoxia-tolerant animals do maintain immunity in low oxygen conditions, but that the sensitivity of immune responses may be blunted.
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Affiliation(s)
- Karen L Kadamani
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Samantha M Logan
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
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Wlaschek M, Singh K, Maity P, Scharffetter-Kochanek K. The skin of the naked mole-rat and its resilience against aging and cancer. Mech Ageing Dev 2023; 216:111887. [PMID: 37993056 DOI: 10.1016/j.mad.2023.111887] [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: 07/05/2023] [Revised: 10/10/2023] [Accepted: 11/14/2023] [Indexed: 11/24/2023]
Abstract
The naked mole-rat (NMR) Heterocephalus glaber (from the Greek/latin words ἕτερος, heteros = divergent, κεφαλή, kephalē = head and glabra = hairless) was first described by Rüppell (Fig. 1) and belongs to the Hystricognath (from the Greek words ὕστριξ, hystrix = porcupine and γνάθος, gnathos = jaw) as a suborder of rodents. NMR are characterized by the highest longevity among rodents and reveal a profound cancer resistance. Details of its skin-specific protective and resistance mechanisms against aging and carcinogenesis have so far not been adequately characterized. Recently, our knowledge of NMR skin biology was complemented and expanded by published data using state-of-the art histological and molecular techniques. Here we review and integrate novel published data regarding skin morphology and histology of the aging NMR and the underlying mechanisms at the cellular and molecular level. We relate this data to the longevity of the NMR and its resistance to neoplastic transformation and discuss further open questions to understand its extraordinary longevity. In addition, we will address the exposome, defined as "the total of all non-genetic, endogenous and exogenous environmental influences" on the skin, respiratory tract, stomach, and intestine. Finally, we will discuss in perspective further intriguing possibilities arising from the interaction of skin with other organs.
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Affiliation(s)
- Meinhard Wlaschek
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany.
| | - Karmveer Singh
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany.
| | - Pallab Maity
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany.
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Benvenuto C, Lorenzi MC. Social regulation of reproduction: control or signal? Trends Ecol Evol 2023; 38:1028-1040. [PMID: 37385846 DOI: 10.1016/j.tree.2023.05.009] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 07/01/2023]
Abstract
Traditionally, dominant breeders have been considered to be able to control the reproduction of other individuals in multimember groups that have high variance in reproductive success/reproductive skew (e.g., forced sterility/coercion of conspecifics in eusocial animals; sex-change suppression in sequential hermaphrodites). These actions are typically presented as active impositions by reproductively dominant individuals. However, how can individuals regulate the reproductive physiology of others? Alternatively, all contestants make reproductive decisions, and less successful individuals self-downregulate reproduction in the presence of dominant breeders. Shifting perspective from a top-down manipulation to a broader view, which includes all contenders, and using a multitaxon approach, we propose a unifying framework for the resolution of reproductive skew conflicts based on signalling rather than control, along a continuum of levels of strategic regulation of reproduction.
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Affiliation(s)
- Chiara Benvenuto
- School of Science, Engineering, and Environment, University of Salford, Salford, UK.
| | - Maria Cristina Lorenzi
- Laboratoire d'Ethologie Expérimentale et Comparée (LEEC), Université Sorbonne Paris Nord, Villetaneuse, France
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Abstract
Conflict and conflict resolution have been argued to be fundamental to the major transitions in evolution. These were key events in life's history in which previously independently living individuals cooperatively formed a higher-level individual, such as a multicellular organism or eusocial colony. Conflict has its central role because, to proceed stably, the evolution of individuality in each major transition required within-individual conflict to be held in check. This review revisits the role of conflict and conflict resolution in the major transitions, addressing recent work arguing for a minor role. Inclusive fitness logic suggests that differences between the kin structures of clones and sexual families support the absence of conflict at the origin of multicellularity but, by contrast, suggest that key conflicts existed at the origin of eusociality. A principal example is conflict over replacing the founding queen (queen replacement). Following the origin of each transition, conflict remained important, because within-individual conflict potentially disrupts the attainment of maximal individuality (organismality) in the system. The conclusion is that conflict remains central to understanding the major transitions, essentially because conflict arises from differences in inclusive fitness optima while conflict resolution can help the system attain a high degree of coincidence of inclusive fitness interests.
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Affiliation(s)
- Andrew F. G. Bourke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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Devereaux MEM, Pamenter ME. Adenosine and γ-aminobutyric acid partially regulate metabolic and ventilatory responses of Damaraland mole-rats to acute hypoxia. J Exp Biol 2023; 226:jeb246186. [PMID: 37694288 PMCID: PMC10565114 DOI: 10.1242/jeb.246186] [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: 05/24/2023] [Accepted: 09/01/2023] [Indexed: 09/12/2023]
Abstract
Fossorial Damaraland mole-rats (Fukomys damarensis) mount a robust hypoxic metabolic response (HMR) but a blunted hypoxic ventilatory response (HVR) to acute hypoxia. Although these reflex physiological responses have been described previously, the underlying signalling pathways are entirely unknown. Of particular interest are contributions from γ-aminobutyric acid (GABA), which is the primary inhibitory neurotransmitter in the nervous system of most adult mammals, and adenosine, the accumulation of which increases during hypoxia as a breakdown product of ATP. Therefore, we hypothesized that GABAergic and/or adenosinergic signalling contributes to the blunted HVR and robust HMR in Damaraland mole-rats. To test this hypothesis, we injected adult animals with saline alone (controls), or 100 mg kg-1 aminophylline or 1 mg kg-1 bicuculline, to block adenosine or GABAA receptors, respectively. We then used respirometry, plethysmography and thermal RFID probes to non-invasively measure metabolic, ventilator and thermoregulatory responses, respectively, to acute hypoxia (1 h in 5 or 7% O2) in awake and freely behaving animals. We found that bicuculline had relatively minor effects on metabolism and thermoregulation but sensitized ventilation such that the HVR became manifest at 7% instead of 5% O2 and was greater in magnitude. Aminophylline increased metabolic rate, ventilation and body temperature in normoxia, and augmented the HMR and HVR. Taken together, these findings indicate that adenosinergic and GABAergic signalling play important roles in mediating the robust HMR and blunted HVR in Damaraland mole-rats.
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Affiliation(s)
| | - Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
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Devereaux MEM, Chiasson S, Brennan KF, Pamenter ME. The glutamatergic drive to breathe is reduced in severe but not moderate hypoxia in Damaraland mole-rats. J Exp Biol 2023; 226:jeb246185. [PMID: 37589556 PMCID: PMC10565110 DOI: 10.1242/jeb.246185] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023]
Abstract
Damaraland mole-rats (Fukomys damarensis) are a hypoxia-tolerant fossorial species that exhibit a robust hypoxic metabolic response (HMR) and blunted hypoxic ventilatory response (HVR). Whereas the HVR of most adult mammals is mediated by increased excitatory glutamatergic signalling, naked mole-rats, which are closely related to Damaraland mole-rats, do not utilize this pathway. Given their phylogenetic relationship and similar lifestyles, we hypothesized that the signalling mechanisms underlying physiological responses to acute hypoxia in Damaraland mole-rats are like those of naked mole-rats. To test this, we used pharmacological antagonists of glutamatergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and N-methyl-d-aspartate receptors (NMDARs), combined with plethysmography, respirometry and thermal RFID chips, to non-invasively evaluate the role of excitatory AMPAR and NMDAR signalling in mediating ventilatory, metabolic and thermoregulatory responses, respectively, to 1 h of 5 or 7% O2. We found that AMPAR or NMDAR antagonism have minimal impacts on the HMR or hypoxia-mediated changes in thermoregulation. Conversely, the 'blunted' HVR of Damaraland mole-rats is reduced by either AMPAR or NMDAR antagonism such that the onset of the HVR occurs in less severe hypoxia. In more severe hypoxia, antagonists have no impact, suggesting that these receptors are already inhibited. Together, these findings indicate that the glutamatergic drive to breathe decreases in Damaraland mole-rats exposed to severe hypoxia. These findings differ from other adult mammals, in which the glutamatergic drive to breathe increases with hypoxia.
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Affiliation(s)
| | - Sarah Chiasson
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Kate F. Brennan
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
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9
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Sorek M, Berger SL. Neuromodulators and neuroepigenetics of social behavior in ants. Ann N Y Acad Sci 2023; 1528:5-12. [PMID: 37581481 PMCID: PMC10592194 DOI: 10.1111/nyas.15055] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
Eusocial insects exemplify a remarkable system of division of labor within the same colony. This behavioral range, which is sometimes accompanied by morphological or physiological differences, provides an opportunity to study the relationship between complex behaviors and their underlying molecular mechanisms. This is especially true in ants because certain genera have an elaborate caste system and can dramatically change their stereotypical behavior over their lifetime. Recent studies experimentally alter ant behavior over short times, thus opening the study of underlying plasticity pathways. The molecular underpinnings of these behaviors are neuromodulators as well as the regulation of chromatin. Here, we concisely review the current understanding of the relationship between neuromodulators, epigenetics, and social behavior in ants. We discuss future directions in light of experimental limitations of the ant system.
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Affiliation(s)
- Matan Sorek
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Shelley L. Berger
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Epigenetics Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Parey E, Fernandez-Aroca D, Frost S, Uribarren A, Park TJ, Zöttl M, St John Smith E, Berthelot C, Villar D. Phylogenetic modeling of enhancer shifts in African mole-rats reveals regulatory changes associated with tissue-specific traits. Genome Res 2023; 33:1513-1526. [PMID: 37625847 PMCID: PMC10620049 DOI: 10.1101/gr.277715.123] [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] [Received: 01/18/2023] [Accepted: 08/24/2023] [Indexed: 08/27/2023]
Abstract
Changes in gene regulation are thought to underlie most phenotypic differences between species. For subterranean rodents such as the naked mole-rat, proposed phenotypic adaptations include hypoxia tolerance, metabolic changes, and cancer resistance. However, it is largely unknown what regulatory changes may associate with these phenotypic traits, and whether these are unique to the naked mole-rat, the mole-rat clade, or are also present in other mammals. Here, we investigate regulatory evolution in the heart and liver from two African mole-rat species and two rodent outgroups using genome-wide epigenomic profiling. First, we adapted and applied a phylogenetic modeling approach to quantitatively compare epigenomic signals at orthologous regulatory elements and identified thousands of promoter and enhancer regions with differential epigenomic activity in mole-rats. These elements associate with known mole-rat adaptations in metabolic and functional pathways and suggest candidate genetic loci that may underlie mole-rat innovations. Second, we evaluated ancestral and species-specific regulatory changes in the study phylogeny and report several candidate pathways experiencing stepwise remodeling during the evolution of mole-rats, such as the insulin and hypoxia response pathways. Third, we report nonorthologous regulatory elements overlap with lineage-specific repetitive elements and appear to modify metabolic pathways by rewiring of HNF4 and RAR/RXR transcription factor binding sites in mole-rats. These comparative analyses reveal how mole-rat regulatory evolution informs previously reported phenotypic adaptations. Moreover, the phylogenetic modeling framework we propose here improves upon the state of the art by addressing known limitations of inter-species comparisons of epigenomic profiles and has broad implications in the field of comparative functional genomics.
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Affiliation(s)
- Elise Parey
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Diego Fernandez-Aroca
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom
| | - Stephanie Frost
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom
| | - Ainhoa Uribarren
- Cambridge Institute, Cancer Research UK and University of Cambridge, Cambridge CB2 0RE, United Kingdom
| | - Thomas J Park
- Department of Biological Sciences and Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Markus Zöttl
- Department of Biology and Environmental Science, Linnaeus University, 44054 Kalmar, Sweden
| | - Ewan St John Smith
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, United Kingdom
| | - Camille Berthelot
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France;
- Institut Pasteur, Université Paris Cité, CNRS UMR 3525, INSERM UA12, Comparative Functional Genomics Group, F-75015 Paris, France
| | - Diego Villar
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom;
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Thorley J, Bensch HM, Finn K, Clutton-Brock T, Zöttl M. Damaraland mole-rats do not rely on helpers for reproduction or survival. Evol Lett 2023; 7:203-215. [PMID: 37475748 PMCID: PMC10355180 DOI: 10.1093/evlett/qrad023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/23/2023] [Accepted: 05/05/2023] [Indexed: 07/22/2023] Open
Abstract
In eusocial invertebrates and obligate cooperative breeders, successful reproduction is dependent on assistance from non-breeding group members. Although naked (Heterocephalus glaber) and Damaraland mole-rats (Fukomys damarensis) are often described as eusocial and their groups are suggested to resemble those of eusocial insects more closely than groups of any other vertebrate, the extent to which breeding individuals benefit from the assistance of non-breeding group members is unclear. Here we show that, in wild Damaraland mole-rats, prospective female breeders usually disperse and settle alone in new burrow systems where they show high survival rates and remain in good body condition-often for several years-before being joined by males. In contrast to many obligate cooperative vertebrates, pairs reproduced successfully without non-breeding helpers, and the breeding success of experimentally formed pairs was similar to that of larger, established groups. Though larger breeding groups recruited slightly more pups than smaller groups, adult survival was independent of group size and group size had mixed effects on the growth of non-breeders. Our results suggest that Damaraland mole-rats do not need groups to survive and that cooperative breeding in the species is not obligate as pairs can-and frequently do-reproduce without the assistance of helpers. While re-emphasizing the importance of ecological constraints on dispersal in social mole-rats, the mixed effects of group size in our study suggest that indirect benefits accrued through cooperative behavior may have played a less prominent role in the evolution of mole-rat group-living than previously thought.
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Affiliation(s)
- Jack Thorley
- Corresponding author: Department of Zoology, Downing Street, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom.
| | | | - Kyle Finn
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Tim Clutton-Brock
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Markus Zöttl
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
- Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
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12
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Martinez Q, Okrouhlík J, Šumbera R, Wright M, Araújo R, Braude S, Hildebrandt TB, Holtze S, Ruf I, Fabre PH. Mammalian maxilloturbinal evolution does not reflect thermal biology. Nat Commun 2023; 14:4425. [PMID: 37479710 PMCID: PMC10361988 DOI: 10.1038/s41467-023-39994-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 07/07/2023] [Indexed: 07/23/2023] Open
Abstract
The evolution of endothermy in vertebrates is a major research topic in recent decades that has been tackled by a myriad of research disciplines including paleontology, anatomy, physiology, evolutionary and developmental biology. The ability of most mammals to maintain a relatively constant and high body temperature is considered a key adaptation, enabling them to successfully colonize new habitats and harsh environments. It has been proposed that in mammals the anterior nasal cavity, which houses the maxilloturbinal, plays a pivotal role in body temperature maintenance, via a bony system supporting an epithelium involved in heat and moisture conservation. The presence and the relative size of the maxilloturbinal has been proposed to reflect the endothermic conditions and basal metabolic rate in extinct vertebrates. We show that there is no evidence to relate the origin of endothermy and the development of some turbinal bones by using a comprehensive dataset of µCT-derived maxilloturbinals spanning most mammalian orders. Indeed, we demonstrate that neither corrected basal metabolic rate nor body temperature significantly correlate with the relative surface area of the maxilloturbinal. Instead, we identify important variations in the relative surface area, morpho-anatomy, and complexity of the maxilloturbinal across the mammalian phylogeny and species ecology.
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Affiliation(s)
- Quentin Martinez
- Institut des Sciences de l'Évolution (ISEM, UMR 5554 CNRS-IRD-UM), Université de Montpellier, Place E. Bataillon - CC 064 - 34095, Montpellier Cedex 5, Montpellier, France.
- Staatliches Museum für Naturkunde Stuttgart, DE-70191, Stuttgart, Germany.
| | - Jan Okrouhlík
- Department of Zoology, Faculty of Science, University of South Bohemia, 37005, České Budějovice, Czech Republic
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, 37005, České Budějovice, Czech Republic
| | - Mark Wright
- Institut des Sciences de l'Évolution (ISEM, UMR 5554 CNRS-IRD-UM), Université de Montpellier, Place E. Bataillon - CC 064 - 34095, Montpellier Cedex 5, Montpellier, France
- Department of Organismic and Evolutionary Biology & Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - Ricardo Araújo
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Stan Braude
- Biology Department, Washington University, St. Louis, MO, 63130, USA
| | - Thomas B Hildebrandt
- Department of Reproduction Management, Leibniz-Instiute for Zoo and Wildlife Research, 10315, Berlin, Germany
- Faculty of Veterinary Medicine, Freie Universität, Berlin, Germany
| | - Susanne Holtze
- Department of Reproduction Management, Leibniz-Instiute for Zoo and Wildlife Research, 10315, Berlin, Germany
| | - Irina Ruf
- Abteilung Messelforschung und Mammalogie, Senckenberg Forschungsinstitut und Naturmuseum Frankfurt, 60325, Frankfurt am Main, Germany
| | - Pierre-Henri Fabre
- Institut des Sciences de l'Évolution (ISEM, UMR 5554 CNRS-IRD-UM), Université de Montpellier, Place E. Bataillon - CC 064 - 34095, Montpellier Cedex 5, Montpellier, France
- Mammal Section, Department of Life Sciences, The Natural History Museum, SW7 5DB, London, United Kingdom
- Institut Universitaire de France (IUF), Paris, France
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13
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Park TJ, Reznick J. Extreme Physiology Extreme Tolerance to Hypoxia, Hypercapnia, and Pain in the Naked Mole-Rat. J Muscle Res Cell Motil 2023; 44:61-72. [PMID: 35854159 PMCID: PMC10329625 DOI: 10.1007/s10974-022-09623-3] [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: 02/24/2022] [Accepted: 06/04/2022] [Indexed: 10/17/2022]
Abstract
Challenging environmental conditions can drive the evolution of extreme physiological traits. The naked mole-rat has evolved to survive and thrive in a low oxygen, high carbon dioxide environment that would be deadly to humans and most other mammals. The naked mole-rat's lifestyle is unusual in that this species combines subterranean living and living in large, social groups of up to 300 + individuals. Many respiring animals in a closed environment can lead to depletion of oxygen (hypoxia) and accumulation of carbon dioxide (hypercapnia). Naked mole-rats display a variety of physiological traits that negate the adverse effects of living in this atmosphere. For hypoxia tolerance, naked mole-rats have a low resting metabolism, high affinity hemoglobin, intrinsic brain tolerance, the ability to use fructose for anaerobic glycolysis, and the ability to enter a low energy, suspended animation-like state. For hypercapnia tolerance, these animals have a mutation in a voltage gated sodium channel that effectively eliminates neuronal responses to tissue acidosis. In other mammals, acidosis from exposure to high concentrations of carbon dioxide induces pain and pulmonary edema. Understanding these mechanisms of extreme physiology is not only inherently interesting, but it may lead to biomedical breakthroughs in research on heart attacks, strokes, and pain pathologies.
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Affiliation(s)
- Thomas J Park
- Department of Biological Sciences and Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, IL, United States of America.
| | - Jane Reznick
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany.
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14
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Lathe R, St Clair D. Programmed ageing: decline of stem cell renewal, immunosenescence, and Alzheimer's disease. Biol Rev Camb Philos Soc 2023. [PMID: 37068798 DOI: 10.1111/brv.12959] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 04/19/2023]
Abstract
The characteristic maximum lifespan varies enormously across animal species from a few hours to hundreds of years. This argues that maximum lifespan, and the ageing process that itself dictates lifespan, are to a large extent genetically determined. Although controversial, this is supported by firm evidence that semelparous species display evolutionarily programmed ageing in response to reproductive and environmental cues. Parabiosis experiments reveal that ageing is orchestrated systemically through the circulation, accompanied by programmed changes in hormone levels across a lifetime. This implies that, like the circadian and circannual clocks, there is a master 'clock of age' (circavital clock) located in the limbic brain of mammals that modulates systemic changes in growth factor and hormone secretion over the lifespan, as well as systemic alterations in gene expression as revealed by genomic methylation analysis. Studies on accelerated ageing in mice, as well as human longevity genes, converge on evolutionarily conserved fibroblast growth factors (FGFs) and their receptors, including KLOTHO, as well as insulin-like growth factors (IGFs) and steroid hormones, as key players mediating the systemic effects of ageing. Age-related changes in these and multiple other factors are inferred to cause a progressive decline in tissue maintenance through failure of stem cell replenishment. This most severely affects the immune system, which requires constant renewal from bone marrow stem cells. Age-related immune decline increases risk of infection whereas lifespan can be extended in germfree animals. This and other evidence suggests that infection is the major cause of death in higher organisms. Immune decline is also associated with age-related diseases. Taking the example of Alzheimer's disease (AD), we assess the evidence that AD is caused by immunosenescence and infection. The signature protein of AD brain, Aβ, is now known to be an antimicrobial peptide, and Aβ deposits in AD brain may be a response to infection rather than a cause of disease. Because some cognitively normal elderly individuals show extensive neuropathology, we argue that the location of the pathology is crucial - specifically, lesions to limbic brain are likely to accentuate immunosenescence, and could thus underlie a vicious cycle of accelerated immune decline and microbial proliferation that culminates in AD. This general model may extend to other age-related diseases, and we propose a general paradigm of organismal senescence in which declining stem cell proliferation leads to programmed immunosenescence and mortality.
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Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, Chancellor's Building, University of Edinburgh Medical School, Little France, Edinburgh, EH16 4SB, UK
| | - David St Clair
- Institute of Medical Sciences, School of Medicine, University of Aberdeen, Aberdeen, AB25 2ZD, UK
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15
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Walters ET, Crook RJ, Neely GG, Price TJ, Smith ESJ. Persistent nociceptor hyperactivity as a painful evolutionary adaptation. Trends Neurosci 2023; 46:211-227. [PMID: 36610893 PMCID: PMC9974896 DOI: 10.1016/j.tins.2022.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [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: 09/29/2022] [Revised: 12/05/2022] [Accepted: 12/16/2022] [Indexed: 01/07/2023]
Abstract
Chronic pain caused by injury or disease of the nervous system (neuropathic pain) has been linked to persistent electrical hyperactivity of the sensory neurons (nociceptors) specialized to detect damaging stimuli and/or inflammation. This pain and hyperactivity are considered maladaptive because both can persist long after injured tissues have healed and inflammation has resolved. While the assumption of maladaptiveness is appropriate in many diseases, accumulating evidence from diverse species, including humans, challenges the assumption that neuropathic pain and persistent nociceptor hyperactivity are always maladaptive. We review studies indicating that persistent nociceptor hyperactivity has undergone evolutionary selection in widespread, albeit selected, animal groups as a physiological response that can increase survival long after bodily injury, using both highly conserved and divergent underlying mechanisms.
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Affiliation(s)
- Edgar T Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Robyn J Crook
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - G Gregory Neely
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Theodore J Price
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Ewan St John Smith
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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16
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Amoroso VG, Zhao A, Vargas I, Park TJ. Naked Mole-Rats Demonstrate Profound Tolerance to Low Oxygen, High Carbon Dioxide, and Chemical Pain. Animals (Basel) 2023; 13:ani13050819. [PMID: 36899677 PMCID: PMC10000161 DOI: 10.3390/ani13050819] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/21/2023] [Accepted: 02/21/2023] [Indexed: 03/12/2023] Open
Abstract
Naked mole-rats (Heterocephalus glaber) are very unusual among subterranean mammals in that they live in large colonies and are extremely social, spending large amounts of time gathered together in underground nests more than a meter below the surface. Many respiring individuals resting in deep, poorly ventilated nests deplete the oxygen supply and increase the concentration of carbon dioxide. Consistent with living in that atmosphere, naked mole-rats tolerate levels of low oxygen and high carbon dioxide that are deadly to most surface-dwelling mammals. Naked mole-rats appear to have evolved a number of remarkable adaptations to be able to thrive in this harsh atmosphere. In order to successfully survive low oxygen atmospheres, they conserve energy utilization by reducing the physiological activity of all organs, manifest by reduced heart rate and brain activity. Amazingly, they resort to the anaerobic metabolism of fructose rather than glucose as a fuel to generate energy when challenged by anoxia. Similarly, high carbon dioxide atmospheres normally cause tissue acidosis, while naked mole-rats have a genetic mutation preventing both acid-induced pain and pulmonary edema. Together, these putative adaptations and the tolerances they provide make the naked mole-rat an important model for studying a host of biomedical challenges.
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Affiliation(s)
- Vince G Amoroso
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Aishi Zhao
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Isabel Vargas
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Thomas J Park
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
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17
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Brieño-Enríquez MA, Faykoo-Martinez M, Goben M, Grenier JK, McGrath A, Prado AM, Sinopoli J, Wagner K, Walsh PT, Lopa SH, Laird DJ, Cohen PE, Wilson MD, Holmes MM, Place NJ. Postnatal oogenesis leads to an exceptionally large ovarian reserve in naked mole-rats. Nat Commun 2023; 14:670. [PMID: 36810851 PMCID: PMC9944903 DOI: 10.1038/s41467-023-36284-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 01/24/2023] [Indexed: 02/24/2023] Open
Abstract
In the long-lived naked mole-rat (NMR), the entire process of oogenesis occurs postnatally. Germ cell numbers increase significantly in NMRs between postnatal days 5 (P5) and P8, and germs cells positive for proliferation markers (Ki-67, pHH3) are present at least until P90. Using pluripotency markers (SOX2 and OCT4) and the primordial germ cell (PGC) marker BLIMP1, we show that PGCs persist up to P90 alongside germ cells in all stages of female differentiation and undergo mitosis both in vivo and in vitro. We identified VASA+ SOX2+ cells at 6 months and at 3-years in subordinate and reproductively activated females. Reproductive activation was associated with proliferation of VASA+ SOX2+ cells. Collectively, our results suggest that highly desynchronized germ cell development and the maintenance of a small population of PGCs that can expand upon reproductive activation are unique strategies that could help to maintain the NMR's ovarian reserve for its 30-year reproductive lifespan.
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Affiliation(s)
- Miguel Angel Brieño-Enríquez
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
- Aging Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Mariela Faykoo-Martinez
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Mississauga, Mississauga, ON, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Meagan Goben
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jennifer K Grenier
- RNA sequencing core and Center for Reproductive Genomics, College of Veterinary, Cornell University, Ithaca, NY, USA
| | - Ashley McGrath
- Department of Population Medicine & Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Alexandra M Prado
- Department of Population Medicine & Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Jacob Sinopoli
- Department of Population Medicine & Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Kate Wagner
- Department of Population Medicine & Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Patrick T Walsh
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Samia H Lopa
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Diana J Laird
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Paula E Cohen
- Center for Reproductive Genomics, Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| | - Michael D Wilson
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Melissa M Holmes
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Mississauga, Mississauga, ON, Canada
| | - Ned J Place
- Department of Population Medicine & Diagnostic Sciences, Cornell University, Ithaca, NY, USA.
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18
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Urriola-Muñoz P, Pattison LA, Smith ESJ. Dysregulation of ADAM10 shedding activity in naked mole-rat fibroblasts is due to deficient phosphatidylserine externalization. J Cell Physiol 2023; 238:761-775. [PMID: 36790936 DOI: 10.1002/jcp.30972] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/16/2023]
Abstract
The naked mole-rat (NMR, Heterocephalus glaber) is of significant interest to biogerontological research, rarely developing age-associated diseases, such as cancer. The transmembrane glycoprotein CD44 is upregulated in certain cancers and CD44 cleavage by a disintegrin and metalloproteinase 10 (ADAM10) regulates cellular migration. Here we provide evidence that mature ADAM10 is expressed in NMR primary skin fibroblasts (NPSF), and that ionomycin increases cell surface ADAM10 localization. However, we observed an absence of ADAM10 mediated CD44 cleavage, as well as shedding of exogenous and overexpressed betacellulin in NPSF, whereas in mouse primary skin fibroblasts ionomycin induced ADAM10-dependent cleavage of both CD44 and betacellulin. Overexpressing a hyperactive form of the Ca2+ -dependent phospholipid scramblase ANO6 in NPSF increased phosphatidylserine (PS) externalization, which rescued the ADAM10 sheddase activity and promoted cell migration in NPSF in an ADAM10-dependent manner. These findings suggest that dysregulation of ADAM10 shedding activity is due to a deficient PS externalization in NMR.
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Affiliation(s)
| | - Luke A Pattison
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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19
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Abstract
Naked mole-rats (NMRs, Heterocephalus glaber) are the longest-lived rodents with a maximum life span exceeding 37 years. They exhibit a delayed aging phenotype and resistance to age-related functional decline/diseases. Specifically, they do not display increased mortality with age, maintain several physiological functions until nearly the end of their lifetime, and rarely develop cancer and Alzheimer's disease. NMRs live in a hypoxic environment in underground colonies in East Africa and are highly tolerant of hypoxia. These unique characteristics of NMRs have attracted considerable interest from zoological and biomedical researchers. This review summarizes previous studies of the ecology, hypoxia tolerance, longevity/delayed aging, and cancer resistance of NMRs and discusses possible mechanisms contributing to their healthy aging. In addition, we discuss current issues and future perspectives to fully elucidate the mechanisms underlying delayed aging and resistance to age-related diseases in NMRs.
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Affiliation(s)
- Kaori Oka
- Department of Aging and Longevity Research, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan; , ,
| | - Masanori Yamakawa
- Department of Evolutionary Studies of Biosystems, Sokendai (The Graduate University for Advanced Studies), Kanagawa, Japan; ,
| | - Yoshimi Kawamura
- Department of Aging and Longevity Research, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan; , ,
| | - Nobuyuki Kutsukake
- Department of Evolutionary Studies of Biosystems, Sokendai (The Graduate University for Advanced Studies), Kanagawa, Japan; , .,Research Center for Integrative Evolutionary Science, Sokendai (The Graduate University for Advanced Studies), Kanagawa, Japan
| | - Kyoko Miura
- Department of Aging and Longevity Research, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan; , , .,Center for Metabolic Regulation of Healthy Aging, Kumamoto University, Kumamoto, Japan
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20
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Li M, Peng Y, Chen W, Gao Y, Yang M, Li J, He J. Active Nrf2 signaling flexibly regulates HO-1 and NQO-1 in hypoxic Gansu Zokor (Eospalax cansus). Comp Biochem Physiol B Biochem Mol Biol 2023; 264:110811. [PMID: 36372272 DOI: 10.1016/j.cbpb.2022.110811] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
Gansu zokor (Eospalax cansus) is a typical subterranean rodent species with resistance to ambient hypoxia. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling plays a key role in regulating redox homeostasis. However, little is known about the regulation of Nrf2 signaling in Gansu zokor. We exposed Gansu zokors and SD rats to chronic hypoxia (44 h at 10.5% O2) or acute hypoxia (6 h at 6.5% O2) andmeasured the activities of heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO-1),gene expression of HO-1, NQO-1, Nrf2, Kelch-like ECH-associated protein-1 (KEAP1), and β-transducin repeat-containing protein (β-TRCP) in the brain and liver. We found that Gansu zokor increased the NQO-1 protein content and activity, HO-1 protein content in the brain, and increased HO-1 activity and mRNA level, NQO-1 activity and protein content in the liver by up regulating Nrf2 gene expression under chronic hypoxia. Although acute hypoxia enhanced the expression of Nrf2 gene, only the level of HO-1 mRNA in the liver increased. Besides, the HO-1 and NQO-1 genes in the brain, HO-1 genes and NQO-1 mRNA in the Gansu zokor liver were significantly higher than those in SD rats under normoxia. Negative regulators of Nrf2 signaling were tissue specific: KEAP1 protein decreased in the brain, and β-TRCP decreased in the liver. The Nrf2 signaling and expression of downstream antioxidant enzymes were different under different oxygen concentrations, reflecting the flexible characteristics of Gansu zokor to deal with the hypoxic environment.
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Affiliation(s)
- Meng Li
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China
| | - Yifan Peng
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China
| | - Wenjun Chen
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China
| | - Yongjiao Gao
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China
| | - Maohong Yang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China
| | - Jingang Li
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China
| | - Jianping He
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, College of Life Science, Shaanxi Normal University, Xi'an, China.
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21
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Marks de Chabris NC, Sabir S, Perkins G, Cheng H, Ellisman MH, Pamenter ME. Short communication: Acute hypoxia does not alter mitochondrial abundance in naked mole-rats. Comp Biochem Physiol A Mol Integr Physiol 2023; 276:111343. [PMID: 36379380 DOI: 10.1016/j.cbpa.2022.111343] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 08/26/2022] [Revised: 10/20/2022] [Accepted: 11/08/2022] [Indexed: 11/15/2022]
Abstract
Hypoxia poses a significant energetic challenge and most species exhibit metabolic remodelling when exposed to prolonged hypoxia. One component of this remodelling is mitochondrial biogenesis/mitophagy, which alter mitochondrial abundance and helps to adjust metabolic throughput to match changes in energy demands in hypoxia. However, how acute hypoxia impacts mitochondrial abundance in hypoxia-tolerant species is poorly understood. To help address this gap, we exposed hypoxia-tolerant naked mole-rats to 3 h of normoxia or acute hypoxia (5% O2) and measured changes in mitochondrial abundance using two well-established markers: citrate synthase (CS) enzyme activity and mitochondrial DNA (mtDNA) abundance. We found that neither marker changed with hypoxia in brain, liver, or kidney, suggesting that mitochondrial biogenesis is not initiated during acute hypoxia in these tissues. Conversely in skeletal muscle, the ratio of CS activity to total protein decreased 50% with hypoxia. However, this change was likely driven by an increase in soluble protein density in hypoxia because CS activity was unchanged relative to wet tissue weight and the mtDNA copy number was unchanged. To confirm this, we examined skeletal muscle mitochondria using transmission electron microscopy and found no change in mitochondrial volume density. Taken together with previous studies of mitochondrial respiratory function, our present findings suggest that naked mole-rats primarily rely on tissue-specific functional remodelling of metabolic pathways and mitochondrial respiratory throughput, and not physical changes in mitochondrial number or volume, to adjust to short-term hypoxic exposure.
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Affiliation(s)
| | - Soulene Sabir
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Guy Perkins
- National Center for Microscopy and Imaging Research, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Hang Cheng
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Marc H Ellisman
- National Center for Microscopy and Imaging Research, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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22
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Eaton L, Welch I, Halal AK, Bengtsson J, Pamenter ME. Apocynin reduces dihydroethidium fluorescence in naked mole-rat cortex independently of NADPH oxidase. Comp Biochem Physiol A Mol Integr Physiol 2023; 276:111342. [PMID: 36375753 DOI: 10.1016/j.cbpa.2022.111342] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
Pharmacological agents that modulate cellular targets offer a powerful approach to interrogate the role of a given component in cellular signalling cascades. However, such drugs are often nonspecific and/or have unexpected off-target effects. One cellular target of interest is the NADPH oxidase (NOX) enzyme family, which consume oxygen and produce reactive oxygen species. Among the most widely used inhibitors of NOX is apocynin, but apocynin also has off-target effects that may interfere with detection assays of hydrogen peroxide (H2O2) or directly scavenge H2O2 in some cell lines. Nonetheless, apocynin remains widely used for in vivo studies of brain function. Therefore, we used apocynin and another widely-used NOX inhibitor - diphenyleneiodonium (DPI) - to study the role of NOX in ROS homeostasis of hypoxia-tolerant naked mole-rat cortical brain slices during a normoxia➔hypoxia➔reoxygenation protocol. Using fluorescence microscopy, we found that apocynin decreased dihydroethidium fluorescence from naked mole-rat cortex in all treatment conditions by 65-75% of pre-drug normoxic control. This change was rapid, occurring within minutes of drug perfusion, and reversed equally rapidly upon washout. Conversely, apocynin had no effect on 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA) fluorescence. DPI also had no effect on either fluorescence signal, suggesting that the effect of apocynin is due to indirect actions of the drug and not due to modulation of NOX. Taken together, our results highlight the pitfalls of pharmacological neuroscience and add to the body of evidence suggesting that apocynin is not a useful compound for targeting NOX.
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Affiliation(s)
- Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Isabella Welch
- Department of Biology, University of Ottawa, Ottawa, ON, Canada. https://twitter.com/Isabellawel1998
| | | | - John Bengtsson
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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23
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Eaton L, Wang T, Roy M, Pamenter ME. Naked Mole-Rat Cortex Maintains Reactive Oxygen Species Homeostasis During In Vitro Hypoxia or Ischemia and Reperfusion. Curr Neuropharmacol 2023; 21:1450-1461. [PMID: 35339183 PMCID: PMC10324332 DOI: 10.2174/1570159x20666220327220929] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 09/30/2021] [Revised: 03/07/2022] [Accepted: 03/23/2022] [Indexed: 11/22/2022] Open
Abstract
Neuronal injury during acute hypoxia, ischemia, and following reperfusion are partially attributable to oxidative damage caused by deleterious fluctuations of reactive oxygen species (ROS). In particular, mitochondrial superoxide (O2•-) production is believed to upsurge during lowoxygen conditions and also following reperfusion, before being dismutated to H2O2 and released into the cell. However, disruptions of redox homeostasis may be beneficially attenuated in the brain of hypoxia-tolerant species, such as the naked mole-rat (NMR, Heterocephalus glaber). As such, we hypothesized that ROS homeostasis is better maintained in the brain of NMRs during severe hypoxic/ ischemic insults and following reperfusion. We predicted that NMR brain would not exhibit substantial fluctuations in ROS during hypoxia or reoxygenation, unlike previous reports from hypoxiaintolerant mouse brain. To test this hypothesis, we measured cortical ROS flux using corrected total cell fluorescence measurements from live brain slices loaded with the MitoSOX red superoxide (O2•-) indicator or chloromethyl 2',7'-dichlorodihydrofluorescein diacetate (CM-H2-DCFDA; which fluoresces with whole-cell hydrogen peroxide (H2O2) production) during various low-oxygen treatments, exogenous oxidative stress, and reperfusion. We found that NMR cortex maintained ROS homeostasis during low-oxygen conditions, while mouse cortex exhibited a ~40% increase and a ~30% decrease in mitochondrial O2•- and cellular H2O2 production, respectively. Mitochondrial ROS homeostasis in NMRs was only disrupted following sodium cyanide application, which was similarly observed in mice. Our results suggest that NMRs have evolved strategies to maintain ROS homeostasis during acute bouts of hypoxia and reoxygenation, potentially as an adaptation to life in an intermittently hypoxic environment.
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Affiliation(s)
- Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Tina Wang
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Maria Roy
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
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Majelantle TL, Ganswindt A, Pirk CWW, Bennett NC, Hart DW. Aggression, Boldness, and Exploration Personality Traits in the Subterranean Naked Mole-Rat (Heterocephalus glaber) Disperser Morphs. Animals (Basel) 2022; 12. [PMID: 36428311 DOI: 10.3390/ani12223083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 11/11/2022] Open
Abstract
Animal personality traits (consistent behavioral differences between individuals in their behavior across time and/or situation) affect individual fitness through facets, such as dispersal. In eusocial naked mole-rat (Heterocephalus glaber) colonies, a disperser morph may arise with distinct morphological, behavioral, and physiological characteristics. This study aimed to quantify the personality traits of a cohort of disperser morphs of naked mole-rat (NMR). Behavioral tests were performed on twelve disperser morphs (six males and six females) in an observation tunnel system that was novel and unfamiliar. Novel stimuli (fresh snakeskin, tissue paper, and conspecific of the same sex) were introduced for fifteen minutes, and the behavioral acts of the individual were recorded. A total of 30 behaviors were noted during the behavioral tests of which eight were used to quantify aggression, boldness, and exploration. The NMR disperser morphs showed consistent individual differences in boldness, and exploration across time and test, indicating a distinct personality. In addition, new naked mole-rat responses including disturbance behaviors; confront, barricade, and stay-away, were recorded. Further investigations into the relationships between animal personality traits and social hierarchy position in entire colonies are needed for more informative results as we further investigate the role of personality in cooperatively breeding societies.
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25
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Fatima I, Chen G, Botchkareva NV, Sharov AA, Thornton D, Wilkinson HN, Hardman MJ, Grutzkau A, Pedro de Magalhaes J, Seluanov A, Smith ESJ, Gorbunova V, Mardaryev AN, Faulkes CG, Botchkarev VA. Skin Aging in Long-Lived Naked Mole-Rats Is Accompanied by Increased Expression of Longevity-Associated and Tumor Suppressor Genes. J Invest Dermatol 2022; 142:2853-2863.e4. [PMID: 35691364 PMCID: PMC9613526 DOI: 10.1016/j.jid.2022.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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] [Received: 06/16/2021] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 10/31/2022]
Abstract
Naked mole-rats (NMRs) (Heterocephalus glaber) are long-lived mammals that possess a natural resistance to cancer and other age-related pathologies, maintaining a healthy life span >30 years. In this study, using immunohistochemical and RNA-sequencing analyses, we compare skin morphology, cellular composition, and global transcriptome signatures between young and aged (aged 3‒4 vs. 19‒23 years, respectively) NMRs. We show that similar to aging in human skin, aging in NMRs is accompanied by a decrease in epidermal thickness; keratinocyte proliferation; and a decline in the number of Merkel cells, T cells, antigen-presenting cells, and melanocytes. Similar to that in human skin aging, expression levels of dermal collagens are decreased, whereas matrix metalloproteinase 9 and matrix metalloproteinase 11 levels increased in aged versus in young NMR skin. RNA-sequencing analyses reveal that in contrast to human or mouse skin aging, the transcript levels of several longevity-associated (Igfbp3, Igf2bp3, Ing2) and tumor-suppressor (Btg2, Cdkn1a, Cdkn2c, Dnmt3a, Hic1, Socs3, Sfrp1, Sfrp5, Thbs1, Tsc1, Zfp36) genes are increased in aged NMR skin. Overall, these data suggest that specific features in the NMR skin aging transcriptome might contribute to the resistance of NMRs to spontaneous skin carcinogenesis and provide a platform for further investigations of NMRs as a model organism for studying the biology and disease resistance of human skin.
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Affiliation(s)
- Iqra Fatima
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, United Kingdom
| | - Guodong Chen
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Natalia V Botchkareva
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Andrey A Sharov
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Daniel Thornton
- Genomics of Aging and Rejuvenation Laboratory, Institute of Life Course and Medical Sciences, Univeristy of Liverpool, Liverpool, United Kingdom
| | - Holly N Wilkinson
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, United Kingdom
| | - Matthew J Hardman
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, United Kingdom
| | - Andreas Grutzkau
- Deutsches Rheuma-Forschungszentrum Berlin, Institute of the Leibniz Association, Berlin, Germany
| | - Joao Pedro de Magalhaes
- Genomics of Aging and Rejuvenation Laboratory, Institute of Life Course and Medical Sciences, Univeristy of Liverpool, Liverpool, United Kingdom
| | - Andrei Seluanov
- Department of Biology, School of Arts & Sciences, University of Rochester, Rochester, New York, USA; Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Vera Gorbunova
- Department of Biology, School of Arts & Sciences, University of Rochester, Rochester, New York, USA; Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Andrei N Mardaryev
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, United Kingdom
| | - Chris G Faulkes
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
| | - Vladimir A Botchkarev
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA.
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Brieño-Enriquez MA, Duncan FE, Ghazi A, Klutstein M, Sebastiano V, Tyler J. Editorial: Germ cell development and reproductive aging. Front Cell Dev Biol 2022; 10:1051539. [PMID: 36313559 PMCID: PMC9597615 DOI: 10.3389/fcell.2022.1051539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 09/30/2022] [Indexed: 11/22/2022] Open
Affiliation(s)
- Miguel Angel Brieño-Enriquez
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA, United States
- *Correspondence: Miguel Angel Brieño-Enriquez, ,
| | - Francesca E. Duncan
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Arjumand Ghazi
- Departments of Pediatrics, Developmental Biology and Cell Biology, and Physiology, John G. Rangos Sr. Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Michael Klutstein
- Faculty of Dental Medicine, Institute of Biomedical and Oral Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Vittorio Sebastiano
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
- Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, United States
| | - Jessica Tyler
- Department of Pathology, Laboratory Medicine, Weill Cornell Medicine, New York, NY, United States
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Moya EA. Carotid bodies in naked mole rats: Are the sensing mechanisms still there? Acta Physiol (Oxf) 2022; 236:e13880. [PMID: 36031795 DOI: 10.1111/apha.13880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 08/24/2022] [Indexed: 01/29/2023]
Affiliation(s)
- Esteban A Moya
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California San Diego, California, USA
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Peng Y, Nanduri J, Wang N, Khan SA, Pamenter M, Prabhakar NR. Carotid body responses to O 2 and CO 2 in hypoxia-tolerant naked mole rats. Acta Physiol (Oxf) 2022; 236:e13851. [PMID: 35757963 PMCID: PMC9787741 DOI: 10.1111/apha.13851] [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: 03/07/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 02/02/2023]
Abstract
AIM Naked mole rats (NMRs) exhibit blunted hypoxic (HVR) and hypercapnic ventilatory responses (HCVR). The mechanism(s) underlying these responses are largely unknown. We hypothesized that attenuated carotid body (CB) sensitivity to hypoxia and hypercapnia contributes to the near absence of ventilatory responses to hypoxia and CO2 in NMRs. METHODS We measured ex vivo CB sensory nerve activity, phrenic nerve activity (an estimation of ventilation), and blood gases in urethane-anesthetized NMRs and C57BL/6 mice breathing normoxic, hypoxic, or hypercapnic gases. CB morphology, carbon monoxide, and H2 S levels were also determined. RESULTS Relative to mice, NMRs had blunted CB and HVR. Morphologically, NMRs have larger CBs, which contained more glomus cells than in mice. Furthermore, NMR glomus cells form a dispersed pattern compared to a clustered pattern in mice. Hemeoxygenase (HO)-1 mRNA was elevated in NMR CBs, and an HO inhibitor increased CB sensitivity to hypoxia in NMRs. This increase was blocked by an H2 S synthesis inhibitor, suggesting that interrupted gas messenger signaling contributes to the blunted CB responses and HVR in NMRs. Regarding hypercapnia, CB and ventilatory responses to CO2 in NMRs were larger than in mice. Carbonic anhydrase (CA)-2 mRNA is elevated in NMR CBs, and a CA inhibitor blocked the augmented CB response to CO2 in NMRs, indicating CA activity regulates augmented CB response to CO2 . CONCLUSIONS Consistent with our hypothesis, impaired CB responses to hypoxia contribute in part to the blunted HVR in NMRs. Conversely, the HCVR and CB are more sensitive to CO2 in NMRs.
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Affiliation(s)
- Ying‐Jie Peng
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Jayasri Nanduri
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Ning Wang
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Shakil A. Khan
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Matthew E. Pamenter
- Department of BiologyUniversity of OttawaOttawaOntarioCanada,University of Ottawa Brain and Mind Research InstituteOttawaOntarioCanada
| | - Nanduri R. Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
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29
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Ragland NH, Compo NR, Wiltshire N, Shepard A, Troutman S, Kissil JL, Engelman RW. Housing and Husbandry Alternatives for Naked Mole Rat Colonies Used in Research Settings. J Am Assoc Lab Anim Sci 2022; 61:412-418. [PMID: 35944976 PMCID: PMC9536831 DOI: 10.30802/aalas-jaalas-22-000035] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Naked mole rats (Heterocephalus glaber) are a unique rodent species originating in Africa and are increasingly being used in research. Their needs and characteristics differ from those of other rodents used in research. Unique housing systems are necessary to address the special macro- and microenvironmental requirements of NMRs. Naked mole rats are one of the 2 known eusocial mammalian species, are extremely long-living, are active burrowers, and are accustomed to a subterranean environment. Unlike typical rats and mice, naked mole rats need specific, unique housing systems that mimic their natural subterranean environment to support health and longevity. Here we provide an overview of naked mole rats and a housing method that can be used in research settings.
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Affiliation(s)
- Natalie H Ragland
- Department of Biomedical Sciences, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis,Corresponding author.
| | - Nicole R Compo
- Department of Comparative Medicine, University of South Florida, Tampa, Florida,,H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Norman Wiltshire
- Department of Comparative Medicine, University of South Florida, Tampa, Florida,,H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Alyssa Shepard
- H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Scott Troutman
- H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Joseph L Kissil
- H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
| | - Robert W Engelman
- Department of Comparative Medicine, University of South Florida, Tampa, Florida,,H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida
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31
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Yamada A, Toya H, Tanahashi M, Kurihara M, Mito M, Iwasaki S, Kurosaka S, Takumi T, Fox A, Kawamura Y, Miura K, Nakagawa S. Species-specific formation of paraspeckles in intestinal epithelium revealed by characterization of NEAT1 in naked mole-rat. RNA 2022; 28:1128-1143. [PMID: 35654483 PMCID: PMC9297846 DOI: 10.1261/rna.079135.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Paraspeckles are mammalian-specific nuclear bodies built on the long noncoding RNA NEAT1_2 The molecular mechanisms of paraspeckle formation have been mainly studied using human or mouse cells, and it is not known if the same molecular components are involved in the formation of paraspeckles in other mammalian species. We thus investigated the expression pattern of NEAT1_2 in naked mole-rats (nNEAT1_2), which exhibit extreme longevity and lower susceptibility to cancer. In the intestine, nNEAT1_2 is widely expressed along the entire intestinal epithelium, which is different from the expression of mNeat1_2 that is restricted to the cells of the distal tip in mice. Notably, the expression of FUS, a FET family RNA binding protein, essential for the formation of paraspeckles both in humans and mice, was absent in the distal part of the intestinal epithelium in naked mole-rats. Instead, mRNAs of other FET family proteins EWSR1 and TAF15 were expressed in the distal region. Exogenous expression of these proteins in Fus-deficient murine embryonic fibroblast cells rescued the formation of paraspeckles. These observations suggest that nNEAT1_2 recruits a different set of RNA binding proteins in a cell type-specific manner during the formation of paraspeckles in different organisms.
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Affiliation(s)
- Akihiro Yamada
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Hikaru Toya
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Mayuko Tanahashi
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Misuzu Kurihara
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Mari Mito
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Saitama 351-0198, Japan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Saitama 351-0198, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan
| | | | - Toru Takumi
- RIKEN Brain Science Institute, Saitama 351-0198, Japan
- Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe 670-0017, Japan
| | - Archa Fox
- School of Human Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
- Harry Perkins Institute of Medical Research, Nedlands, Western Australia 6009, Australia
- School of Molecular Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Yoshimi Kawamura
- Department of Aging and Longevity Research, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan
- Center for Metabolic Regulation of Healthy Aging, Kumamoto University, Kumamoto 860-8556, Japan
| | - Kyoko Miura
- Department of Aging and Longevity Research, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan
- Center for Metabolic Regulation of Healthy Aging, Kumamoto University, Kumamoto 860-8556, Japan
| | - Shinichi Nakagawa
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
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Hadj-Moussa H, Eaton L, Cheng H, Pamenter ME, Storey KB. Naked mole-rats resist the accumulation of hypoxia-induced oxidative damage. Comp Biochem Physiol A Mol Integr Physiol 2022;:111282. [PMID: 35907588 DOI: 10.1016/j.cbpa.2022.111282] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 07/23/2022] [Accepted: 07/23/2022] [Indexed: 01/28/2023]
Abstract
Naked mole-rats are among the few mammals with the ability to endure severe hypoxia. These unique rodents use metabolic rate depression along with various molecular mechanisms to successfully overcome the challenges of oxygen-limitation, which they experience in their underground borrows. While studies have reported that naked mole-rats exhibit inherently higher levels of oxidative damage across their lifespan as compared to mice, it has yet to be determined whether naked mole-rats are vulnerable to oxidative damage during periods of low oxygen exposure. To investigate this phenomenon, we examined cellular oxidative damage markers of macromolecules: DNA oxidation determined as 8-oxo-2'deoxyguanosine (8-OHdG8) levels, RNA oxidation as 8-hydroxyguanosine (8-OHG), protein carbonylation, and lipid peroxidation in normoxic (control), acute (4 h at 7% O2), and chronic (24 h at 7% O2) hypoxia-exposed naked mole-rats. Brain appears to be the most resilient organ to hypoxia-induced oxidative damage, with both brain and heart exhibiting enhanced antioxidant capacity during hypoxia. Levels of DNA and RNA oxidation were minimally changed in all tissues and no changes were observed in protein carbonylation. Most tissues experienced lipid peroxidation, with liver displaying a 9.6-fold increase during hypoxia. Concomitantly, levels of DNA damage repair proteins were dynamically regulated in a tissue-specific manner, with white adipose displaying a significant reduction during hypoxia. Our findings show that naked mole-rats largely avoid hypoxia-induced oxidative damage, possibly due to their high tolerance to redox stress, or to reduced oxidative requirements made possible during their hypometabolic response when oxygen supply is limited.
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Zöttl M, Bensch HM, Finn KT, Hart DW, Thorley J, Bennett NC, Braude S. Capture Order Across Social Bathyergids Indicates Similarities in Division of Labour and Spatial Organisation. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.877221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The social mole-rats of the family Bathyergidae show elaborate social organisation that may include division of labour between breeders and non-breeders as well as across non-breeders within their groups. However, comparative behavioural data across the taxa are rare and contrasts and similarities between species are poorly understood. Field studies of social bathyergids usually involve capturing all group members until the entire group is captured. Because each animal is only captured once and traps are typically placed in close proximity to active foraging areas, the order in which animals are captured provides an indication of the foraging activity of different individuals and of the spatial organisation of the group within the burrow system. Here, we compare the association of capture order with breeding status, sex, and body mass in four species and subspecies of social bathyergids, which vary in group size and represent all three social genera within the family Bathyergidae. We show that in naked and Damaraland mole-rats (Heterocephalus glaber and Fukomys damarensis), male and female breeders are captured later than non-breeders, whereas in two different subspecies of the genus Cryptomys only female breeders are captured later than non-breeders. The effect sizes vary largely and are 10 times larger in naked mole-rats as compared to Fukomys and 3–4 times larger than in Cryptomys. Among non-breeders, sex effects are notably absent in all species and body mass predicted capture order in both naked and Damaraland mole-rats. In naked mole-rats, larger non-breeders were captured earlier than smaller ones, whereas in Damaraland mole-rats intermediate-sized non-breeders were captured first. Our data suggest that there are similarities in behavioural structure and spatial organisation across all social bathyergid species, though the most pronounced differences within groups are found in naked mole-rats.
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Eaton L, Pamenter ME. What to do with low O 2: Redox adaptations in vertebrates native to hypoxic environments. Comp Biochem Physiol A Mol Integr Physiol 2022; 271:111259. [PMID: 35724954 DOI: 10.1016/j.cbpa.2022.111259] [Citation(s) in RCA: 6] [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: 02/26/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 01/05/2023]
Abstract
Reactive oxygen species (ROS) are important cellular signalling molecules but sudden changes in redox balance can be deleterious to cells and lethal to the whole organism. ROS production is inherently linked to environmental oxygen availability and many species live in variable oxygen environments that can range in both severity and duration of hypoxic exposure. Given the importance of redox homeostasis to cell and animal viability, it is not surprising that early studies in species adapted to various hypoxic niches have revealed diverse strategies to limit or mitigate deleterious ROS changes. Although research in this area is in its infancy, patterns are beginning to emerge in the suites of adaptations to different hypoxic environments. This review focuses on redox adaptations (i.e., modifications of ROS production and scavenging, and mitigation of oxidative damage) in hypoxia-tolerant vertebrates across a range of hypoxic environments. In general, evidence suggests that animals adapted to chronic lifelong hypoxia are in homeostasis, and do not encounter major oxidative challenges in their homeostatic environment, whereas animals exposed to seasonal chronic anoxia or hypoxia rapidly downregulate redox balance to match a hypometabolic state and employ robust scavenging pathways during seasonal reoxygenation. Conversely, animals adapted to intermittent hypoxia exposure face the greatest degree of ROS imbalance and likely exhibit enhanced ROS-mitigation strategies. Although some progress has been made, research in this field is patchy and further elucidation of mechanisms that are protective against environmental redox challenges is imperative for a more holistic understanding of how animals survive hypoxic environments.
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Affiliation(s)
- Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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35
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Hite NJ, Sudheimer KD, Anderson L, Sarko DK. Spatial Learning and Memory in the Naked Mole-Rat: Evolutionary Adaptations to a Subterranean Niche. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.879989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Evolutionary adaptation to a subterranean habitat consisting of extensive underground tunnel systems would presumably require adept spatial learning and memory, however, such capabilities have not been characterized to date in naked mole-rats (Heterocephalus glaber) which, like other members of Bathyergidae, are subterranean rodents. The goal of this study was to develop a method for effectively assessing spatial learning and memory by modifying a Hebb-Williams maze for use with these subterranean rodents. Established behavioral tests to assess spatial learning and memory have primarily focused on, and have been optimized for, more typical laboratory rodent species such as mice and rats. In the current study, we utilized species-appropriate motivators, analyzed learning curves associated with maze performance, and tested memory retention in naked mole-rats. Using a modified Hebb-Williams maze, naked mole-rats underwent 3 days of training, consisting of five trials per day wherein they could freely explore the maze in search of the reward chamber. Memory retention was then tested 1 day, 1 week, and 1 month following the last day of training. Performance was analyzed based on latency to the reward chamber, errors made, and distance traveled to reach the reward chamber. Overall, this study established a behavioral paradigm for assessing maze navigation, spatial learning, and spatial memory in subterranean rodents, including optimization of rewards and environmental motivators.
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Huynh KW, Sabir S, Cheng H, Pamenter ME. Acute pH alterations do not impact cardiac mitochondrial respiration in naked mole-rats or mice. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111185. [PMID: 35278722 DOI: 10.1016/j.cbpa.2022.111185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/06/2022] [Accepted: 03/06/2022] [Indexed: 01/04/2023]
Abstract
Energetically demanding conditions such as hypoxia and exercise favour anaerobic metabolism (glycolysis), which leads to acidification of the cellular milieu from ATP hydrolysis and accumulation of the anaerobic end-product, lactate. Cellular acidification may damage mitochondrial proteins and/or alter the H+ gradient across the mitochondrial inner membrane, which may in turn impact mitochondrial respiration and thus aerobic ATP production. Naked mole-rats are among the most hypoxia-tolerant mammals, and putatively experience intermittent environmental and systemic hypoxia while resting and exercising in their underground burrows. Previous studies in naked mole-rat brain, heart, and skeletal muscle mitochondria have demonstrated adaptations that favour improved efficiency in hypoxic conditions; however, the impact of cellular acidification on mitochondrial function has not been explored. We hypothesized that, relative to hypoxia-intolerant mice, naked mole-rat cardiac mitochondrial respiration is less sensitive to cellular pH changes. To test this, we used high-resolution respirometry to measure mitochondrial respiration by permeabilized cardiac muscle fibres from naked mole-rats and mice exposed in vitro to a pH range from 6.6 to 7.6. Surprisingly, we found that acute pH changes do not impact cardiac mitochondrial respiration or compromise mitochondrial integrity in either species. Our results suggest that acute alterations of cellular pH have minimal impact on cardiac mitochondrial respiration.
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Lutermann H. Socializing in an Infectious World: The Role of Parasites in Social Evolution of a Unique Rodent Family. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.879031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transmission of parasites between hosts is facilitated by close contact of hosts. Consequently, parasites have been proposed as an important constraint to the evolution of sociality accounting for its rarity. Despite the presumed costs associated with parasitism, the majority of species of African mole-rats (Family: Bathyergidae) are social. In fact, only the extremes of sociality (i.e., solitary and singular breeding) are represented in this subterranean rodent family. But how did bathyergids overcome the costs of parasitism? Parasite burden is a function of the exposure and susceptibility of a host to parasites. In this review I explore how living in sealed burrow systems and the group defenses that can be employed by closely related group members can effectively reduce the exposure and susceptibility of social bathyergids to parasites. Evidence suggests that this can be achieved largely by investment in relatively cheap and flexible behavioral rather than physiological defense mechanisms. This also shifts the selection pressure for parasites on successful transmission between group members rather than transmission between groups. In turn, this constrains the evolution of virulence and favors socially transmitted parasites (e.g., mites and lice) further reducing the costs of parasitism for social Bathyergidae. I conclude by highlighting directions for future research to evaluate the mechanisms proposed and to consider parasites as facilitators of social evolution not only in this rodent family but also other singular breeders.
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Szafranski K, Wetzel M, Holtze S, Büntjen I, Lieckfeldt D, Ludwig A, Huse K, Platzer M, Hildebrandt T. The Mating Pattern of Captive Naked Mole-Rats Is Best Described by a Monogamy Model. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.855688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Naked mole-rats form colonies with a single reproductively active female surrounded by subordinate workers. Workers perform offspring care, construction and defense of the burrow system, and food supply. Such division of labor, called “cooperative breeding,” is strongly associated with the evolution of monogamous mating behavior, as seen in several mammalian lineages. This association is explained by the evolutionary theory of kin selection, according to which a subordinate adult may help to raise other’s offspring if they are in full sibling relationship. In conflict with this theory, the naked mole-rat is widely considered to be polyandrous, based on reports on multiple males contributing to a colony’s progeny. In order to resolve this contrast, we undertook an in-depth microsatellite-based kinship analysis on captive colonies. Four independent colonies comprising a total of 265 animals were genotyped using a panel of 73 newly established microsatellite markers. Our results show that each mole-rat colony contains a single monogamous breeder pair, which translates to a reproductive skew of 100% for both sexes. This finding, also in conjunction with previously published parental data, favors monogamy as the best-fitting model to describe naked mole-rat reproduction patterns. Polyandry or other polygamous reproduction models are disfavored and should be considered as exceptional. Overall, the empirical genetic data are in agreement with the kin selection theory.
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Freire Jorge P, Goodwin ML, Renes MH, Nijsten MW, Pamenter M. Low Cancer Incidence in Naked Mole-Rats May Be Related to Their Inability to Express the Warburg Effect. Front Physiol 2022; 13:859820. [PMID: 35600297 PMCID: PMC9114474 DOI: 10.3389/fphys.2022.859820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/11/2022] [Indexed: 11/23/2022] Open
Abstract
Metabolic flexibility in mammals enables stressed tissues to generate additional ATP by converting large amounts of glucose into lactic acid; however, this process can cause transient local or systemic acidosis. Certain mammals are adapted to extreme environments and are capable of enhanced metabolic flexibility as a specialized adaptation to challenging habitat niches. For example, naked mole-rats (NMRs) are a fossorial and hypoxia-tolerant mammal whose metabolic responses to environmental stressors markedly differ from most other mammals. When exposed to hypoxia, NMRs exhibit robust hypometabolism but develop minimal acidosis. Furthermore, and despite a very long lifespan relative to other rodents, NMRs have a remarkably low cancer incidence. Most advanced cancers in mammals display increased production of lactic acid from glucose, irrespective of oxygen availability. This hallmark of cancer is known as the Warburg effect (WE). Most malignancies acquire this metabolic phenotype during their somatic evolution, as the WE benefits tumor growth in several ways. We propose that the peculiar metabolism of the NMR makes development of the WE inherently difficult, which might contribute to the extraordinarily low cancer rate in NMRs. Such an adaptation of NMRs to their subterranean environment may have been facilitated by modified biochemical responses with a stronger inhibition of the production of CO2 and lactic acid by a decreased extracellular pH. Since this pH-inhibition could be deeply hard-wired in their metabolic make-up, it may be difficult for malignant cells in NMRs to acquire the WE-phenotype that facilitates cancer growth in other mammals. In the present commentary, we discuss this idea and propose experimental tests of our hypothesis.
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Affiliation(s)
- Pedro Freire Jorge
- Department of Critical Care, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Radiology, Isala Hospital, Zwolle, Netherlands
- *Correspondence: Pedro Freire Jorge,
| | - Matthew L. Goodwin
- Department of Orthopedic Surgery, School of Medicine, Washington University St. Louis, St. Louis, MO, United States
| | - Maurits H. Renes
- Department of Critical Care, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Maarten W. Nijsten
- Department of Critical Care, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Matthew Pamenter
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
- Brain and Mind Research Institute, Faculty of Medicine, University of Ottawa, Ottawa, ON, 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Bégay V, Cirovic B, Barker AJ, Klopfleisch R, Hart DW, Bennett NC, Lewin GR. Immune competence and spleen size scale with colony status in the naked mole-rat. Open Biol 2022; 12:210292. [PMID: 35382566 PMCID: PMC8984379 DOI: 10.1098/rsob.210292] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Naked mole-rats (NM-R; Heterocephalus glaber) live in multi-generational colonies with a social hierarchy, and show low cancer incidence and long life-spans. Here we asked if an immune component might underlie such extreme physiology. The largest lymphoid organ is the spleen, which plays an essential role in responding to immunological insults and may participate in combating cancer and slowing ageing. We investigated the anatomy, molecular composition and function of the NM-R spleen using RNA-sequencing and histological analysis in healthy NM-Rs. Spleen size in healthy NM-Rs showed considerable inter-individual variability, with some animals displaying enlarged spleens. In all healthy NM-Rs, the spleen is a major site of adult haematopoiesis under normal physiological conditions. However, myeloid-to-lymphoid cell ratio is increased and splenic marginal zone showed markedly altered morphology when compared to other rodents. Healthy NM-Rs with enlarged spleens showed potentially better anti-microbial profiles and were much more likely to have a high rank within the colony. We propose that the anatomical plasticity of the spleen might be regulated by social interaction and gives immunological advantage to increase the lifespan of higher-ranked animals.
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Affiliation(s)
- Valérie Bégay
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Laboratory for Molecular Physiology of Somatic Sensation, Robert-Rössle Straße 10, D-13125 Berlin, Germany
| | - Branko Cirovic
- Division of Cellular Immunology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Alison J. Barker
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Laboratory for Molecular Physiology of Somatic Sensation, Robert-Rössle Straße 10, D-13125 Berlin, Germany
| | - Robert Klopfleisch
- Institute of Veterinary Pathology, Free University Berlin, Robert von Ostertag Strasse 15, 14163 Berlin, Germany
| | - Daniel W. Hart
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, Republic of South Africa
| | - Nigel C. Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, Republic of South Africa
| | - Gary R. Lewin
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Laboratory for Molecular Physiology of Somatic Sensation, Robert-Rössle Straße 10, D-13125 Berlin, Germany
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Montoya-sanhueza G, Šumbera R, Bennett NC, Chinsamy A. Developmental Plasticity in the Ossification of the Proximal Femur of Heterocephalus glaber (Bathyergidae, Rodentia). J MAMM EVOL. [DOI: 10.1007/s10914-022-09602-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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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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Huynh KW, Pamenter ME. Lactate inhibits naked mole-rat cardiac mitochondrial respiration. J Comp Physiol B 2022; 192:501-511. [PMID: 35181821 DOI: 10.1007/s00360-022-01430-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 10/16/2021] [Revised: 01/13/2022] [Accepted: 01/29/2022] [Indexed: 12/25/2022]
Abstract
In aerobic conditions, the proton-motive force drives oxidative phosphorylation (OXPHOS) and the conversion of ADP to ATP. In hypoxic environments, OXPHOS is impaired, resulting in energy shortfalls and the accumulation of protons and lactate. This results in cellular acidification, which may impact the activity and/or integrity of mitochondrial enzymes and in turn negatively impact mitochondrial respiration and thus aerobic ATP production. Naked mole-rats (NMRs) are among the most hypoxia-tolerant mammals and putatively experience intermittent hypoxia in their underground burrows. However, if and how NMR cardiac mitochondria are impacted by lactate accumulation in hypoxia is unknown. We predicted that lactate alters mitochondrial respiration in NMR cardiac muscle. To test this, we used high-resolution respirometry to measure mitochondrial respiration in permeabilized cardiac muscle fibres from NMRs exposed to 4 h of in vivo normoxia (21% O2) or hypoxia (7% O2). We found that: (1) cardiac mitochondria cannot directly oxidize lactate, but surprisingly, (2) lactate inhibits mitochondrial respiration, and (3) decreases complex IV maximum respiratory capacity. Finally, (4) in vivo hypoxic exposure decreases the magnitude of lactate-mediated inhibition of mitochondrial respiration. Taken together, our results suggest that lactate may retard electron transport system function in NMR cardiac mitochondria, particularly in normoxia, and that NMR hearts may be primed for anaerobic metabolism.
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Affiliation(s)
- Kenny W Huynh
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt., Ottawa, ON, K1N 6N5, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, 30 Marie Curie Pvt., Ottawa, ON, K1N 6N5, Canada. .,University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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Kerepesi C, Meer MV, Ablaeva J, Amoroso VG, Lee SG, Zhang B, Gerashchenko MV, Trapp A, Yim SH, Lu AT, Levine ME, Seluanov A, Horvath S, Park TJ, Gorbunova V, Gladyshev VN. Epigenetic aging of the demographically non-aging naked mole-rat. Nat Commun 2022; 13:355. [PMID: 35039495 DOI: 10.1038/s41467-022-27959-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 12/23/2021] [Indexed: 12/26/2022] Open
Abstract
The naked mole-rat (NMR) is an exceptionally long-lived rodent that shows no increase of mortality with age, defining it as a demographically non-aging mammal. Here, we perform bisulfite sequencing of the blood of > 100 NMRs, assessing > 3 million common CpG sites. Unsupervised clustering based on sites whose methylation correlates with age reveals an age-related methylome remodeling, and we also observe a methylome information loss, suggesting that NMRs age. We develop an epigenetic aging clock that accurately predicts the NMR age. We show that these animals age much slower than mice and much faster than humans, consistent with their known maximum lifespans. Interestingly, patterns of age-related changes of clock sites in Tert and Prpf19 differ between NMRs and mice, but there are also sites conserved between the two species. Together, the data indicate that NMRs, like other mammals, epigenetically age even in the absence of demographic aging of this species. The exceptionally long-lived naked mole-rat is characterized by the lack of increased mortality with aging. Here the authors perform epigenetic studies to show that naked mole-rats epigenetically age despite their non-increasing mortality rate.
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Singh G, Storey KB. MicroRNA Cues from Nature: A Roadmap to Decipher and Combat Challenges in Human Health and Disease? Cells 2021; 10:3374. [PMID: 34943882 DOI: 10.3390/cells10123374] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/22/2021] [Accepted: 11/27/2021] [Indexed: 12/15/2022] Open
Abstract
MicroRNAs are small non-coding RNA (18–24 nt long) that fine-tune gene expression at the post-transcriptional level. With the advent of “multi-omics” analysis and sequencing approaches, they have now been implicated in every facet of basic molecular networks, including metabolism, homeostasis, and cell survival to aid cellular machinery in adapting to changing environmental cues. Many animals must endure harsh environmental conditions in nature, including cold/freezing temperatures, oxygen limitation (anoxia/hypoxia), and food or water scarcity, often requiring them to revamp their metabolic organization, frequently on a seasonal or life stage basis. MicroRNAs are important regulatory molecules in such processes, just as they are now well-known to be involved in many human responses to stress or disease. The present review outlines the role of miRNAs in natural animal models of environmental stress and adaptation including torpor/hibernation, anoxia/hypoxia tolerance, and freeze tolerance. We also discuss putative medical applications of advances in miRNA biology including organ preservation for transplant, inflammation, ageing, metabolic disorders (e.g., obesity), mitochondrial dysfunction (mitoMirs) as well as specialized miRNA subgroups respective to low temperature (CryomiRs) and low oxygen (OxymiRs). The review also covers differential regulation of conserved and novel miRNAs involved at cell, tissue, and stress specific levels across multiple species and their roles in survival. Ultimately, the species-specific comparison and conserved miRNA responses seen in evolutionarily disparate animal species can help us to understand the complex miRNA network involved in regulating and reorganizing metabolism to achieve diverse outcomes, not just in nature, but in human health and disease.
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Cheng H, Sebaa R, Malholtra N, Lacoste B, El Hankouri Z, Kirby A, Bennett NC, van Jaarsveld B, Hart DW, Tattersall GJ, Harper ME, Pamenter ME. Naked mole-rat brown fat thermogenesis is diminished during hypoxia through a rapid decrease in UCP1. Nat Commun 2021; 12:6801. [PMID: 34815412 PMCID: PMC8610999 DOI: 10.1038/s41467-021-27170-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 11/08/2021] [Indexed: 11/17/2022] Open
Abstract
Naked mole-rats are among the most hypoxia-tolerant mammals. During hypoxia, their body temperature (Tb) decreases via unknown mechanisms to conserve energy. In small mammals, non-shivering thermogenesis in brown adipose tissue (BAT) is critical to Tb regulation; therefore, we hypothesize that hypoxia decreases naked mole-rat BAT thermogenesis. To test this, we measure changes in Tb during normoxia and hypoxia (7% O2; 1-3 h). We report that interscapular thermogenesis is high in normoxia but ceases during hypoxia, and Tb decreases. Furthermore, in BAT from animals treated in hypoxia, UCP1 and mitochondrial complexes I-V protein expression rapidly decrease, while mitochondria undergo fission, and apoptosis and mitophagy are inhibited. Finally, UCP1 expression decreases in hypoxia in three other social African mole-rat species, but not a solitary species. These findings suggest that the ability to rapidly down-regulate thermogenesis to conserve oxygen in hypoxia may have evolved preferentially in social species.
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Affiliation(s)
- Hang Cheng
- grid.28046.380000 0001 2182 2255Department of Biology, University of Ottawa, Ottawa, ON Canada
| | - Rajaa Sebaa
- grid.28046.380000 0001 2182 2255Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON Canada ,grid.28046.380000 0001 2182 2255Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON Canada ,grid.449644.f0000 0004 0441 5692Department of Medical Laboratories, College of Applied Medical Sciences, University of Shaqra, Duwadimi, Saudi Arabia
| | - Nikita Malholtra
- grid.28046.380000 0001 2182 2255Department of Biology, University of Ottawa, Ottawa, ON Canada
| | - Baptiste Lacoste
- grid.28046.380000 0001 2182 2255Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON Canada ,grid.28046.380000 0001 2182 2255University of Ottawa Brain and Mind Research Institute, Ottawa, ON Canada ,grid.412687.e0000 0000 9606 5108Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON Canada
| | - Ziyad El Hankouri
- grid.28046.380000 0001 2182 2255Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON Canada ,grid.28046.380000 0001 2182 2255Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON Canada
| | - Alexia Kirby
- grid.28046.380000 0001 2182 2255Department of Biology, University of Ottawa, Ottawa, ON Canada
| | - Nigel C. Bennett
- grid.49697.350000 0001 2107 2298Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Barry van Jaarsveld
- grid.49697.350000 0001 2107 2298Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel W. Hart
- grid.49697.350000 0001 2107 2298Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Glenn J. Tattersall
- grid.411793.90000 0004 1936 9318Department of Biological Sciences, Brock University, St. Catharines, ON Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada. .,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada.
| | - Matthew E. Pamenter
- grid.28046.380000 0001 2182 2255Department of Biology, University of Ottawa, Ottawa, ON Canada ,grid.28046.380000 0001 2182 2255University of Ottawa Brain and Mind Research Institute, Ottawa, ON Canada
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