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Amaral-Silva L, Santin J. Neural Processing without O 2 and Glucose Delivery: Lessons from the Pond to the Clinic. Physiology (Bethesda) 2024; 39:0. [PMID: 38624246 DOI: 10.1152/physiol.00030.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 04/12/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024] Open
Abstract
Neuronal activity requires a large amount of ATP, leading to a rapid collapse of brain function when aerobic respiration fails. Here, we summarize how rhythmic motor circuits in the brain stem of adult frogs, which normally have high metabolic demands, transform to produce proper output during severe hypoxia associated with emergence from hibernation. We suggest that general principles underlying plasticity in brain bioenergetics may be uncovered by studying nonmammalian models that face extreme environments, yielding new insights to combat neurological disorders involving dysfunctional energy metabolism.
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Affiliation(s)
- Lara Amaral-Silva
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States
- Division of Biology, University of Missouri, Columbia, Missouri, United States
| | - Joseph Santin
- Division of Biology, University of Missouri, Columbia, Missouri, United States
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2
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Christensen NK, Beedholm K, Damsgaard C. Short communication: Maintained visual performance in birds under high altitude hypoxia. Comp Biochem Physiol A Mol Integr Physiol 2024; 296:111691. [PMID: 38971399 DOI: 10.1016/j.cbpa.2024.111691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 06/30/2024] [Accepted: 06/30/2024] [Indexed: 07/08/2024]
Abstract
Birds are highly dependent on their vision for orientation and navigation. The avian eye differs from the mammalian eye as the retina is avascular, leaving the inner, highly metabolically active layers with a very long diffusion distance to the oxygen supply. During flight at high altitudes, birds face a decrease in environmental oxygen partial pressure, which leads to a decrease in arterial oxygen levels. Since oxygen perfusion to the retina is already limited in birds, we hypothesize that visual function is impaired by low oxygen availability. However, the visual performance of birds exposed to hypoxia has not been evaluated before. Here, we assess the optomotor response (OMR) in zebra finches under simulated high-altitude hypoxia (10%) and show that the OMR is largely maintained under hypoxia with only a modest reduction in OMR, demonstrating that birds can largely maintain visual function at high altitudes. The method of our study does not provide insight into the mechanisms involved, but our findings suggest that birds have evolved physiological mechanisms for retinal function at low tissue oxygen levels.
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Affiliation(s)
| | - Kristian Beedholm
- Section for Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Christian Damsgaard
- Section for Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark.
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3
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Huang KR, Liu QY, Zhang YF, Luo YL, Fu C, Pang X, Fu SJ. Whether hypoxia tolerance improved after short-term fasting is closely related to phylogeny but not to foraging mode in freshwater fish species. J Comp Physiol B 2024:10.1007/s00360-024-01588-8. [PMID: 39347810 DOI: 10.1007/s00360-024-01588-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 09/04/2024] [Accepted: 09/15/2024] [Indexed: 10/01/2024]
Abstract
The combined stresses of fasting and hypoxia are common events during the life history of freshwater fish species. Hypoxia tolerance is vital for survival in aquatic environments, which requires organisms to down-regulate their maintenance energetic expenditure while simultaneously preserving physiological features such as oxygen supply capacity under conditions of food deprivation. Generally, infrequent-feeding species who commonly experience food shortages might evolve more adaptive strategies to cope with food deprivation than frequent-feeding species. Thus, the present study aimed to test whether the response of hypoxia tolerance in fish to short-term fasting (2 weeks) varied with different foraging modes. Fasting resulted in similar decreases in maintenance energetic expenditure and similar decreases in Pcrit and Ploe between fishes with different foraging modes, whereas it resulted in decreased oxygen supply capacity only in frequent-feeding fishes. Furthermore, independent of foraging mode, fasting decreased Pcrit and Ploe in all Cypriniformes and Siluriformes species but not in Perciformes species. The mechanism for decreased Pcrit and Ploe in Cypriniformes and Siluriformes species is at least partially due to the downregulated metabolic demand and/or the maintenance of a high oxygen supply capacity while fasting. The present study found that the effect of fasting on hypoxia tolerance depends upon phylogeny in freshwater fish species. The information acquired in the present study is highly valuable in aquaculture industries and can be used for species conservation in the field.
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Affiliation(s)
- Ke-Ren Huang
- Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China
| | - Qian-Ying Liu
- Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China
| | - Yong-Fei Zhang
- Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China
| | - Yu-Lian Luo
- Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China
| | - Cheng Fu
- Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China
| | - Xu Pang
- College of Fisheries, Southwest University, Chongqing, 400715, China
| | - Shi-Jian Fu
- Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, Chongqing, 401331, China.
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4
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Shekhovtsov SV, Bulakhova NA, Tsentalovich YP, Osik NA, Meshcheryakova EN, Poluboyarova TV, Berman DI. Metabolic stability of the Pallas' spadefoot Pelobates vespertinus under extreme hypoxia. J Comp Physiol B 2024:10.1007/s00360-024-01584-y. [PMID: 39292257 DOI: 10.1007/s00360-024-01584-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 07/17/2024] [Accepted: 09/02/2024] [Indexed: 09/19/2024]
Abstract
The Pallas' spadefoot Pelobates vespertinus is a frog species native to eastern Europe and west Siberia. This species resists harsh winter conditions by moving up to 2 m underground. This amphibian is the first species known to withstand extreme air hypoxia. In this study, we investigated the metabolome of liver, heart, and brain of the Pallas' spadefoot after a month-long exposure of hypoxia, with oxygen levels reduced to approximately one-tenth of the air normal content. Surprisingly, our findings revealed a limited impact of hypoxia on the metabolomic profiles. Concentrations of glycolysis end products (lactate and alanine) increased only slightly compared to other amphibians under hypoxia, and no accumulation of succinate was observed. Furthermore, there were no notable changes in the content of adenosine phosphates. These results are consistent with a previous study, which indicated that the Pallas' spadefoot possesses relatively small glycogen and fat reserves before the winter compared to other frogs. It appears that this species conserves energy during winter by minimizing its metabolic activity. These findings corroborated the hypothesis that the survival of P. vespertinus under hypoxic conditions primarily relies on metabolic suppression rather than substantial energy reserves.
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Affiliation(s)
- S V Shekhovtsov
- Institute of Cytology and Genetics SB RAS, Lavrentieva av. 10, Novosibirsk, 630090, Russia.
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, Magadan, 685000, Russia.
| | - N A Bulakhova
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, Magadan, 685000, Russia
| | - Yu P Tsentalovich
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk, 630090, Russia
| | - N A Osik
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk, 630090, Russia
| | - E N Meshcheryakova
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, Magadan, 685000, Russia
| | - T V Poluboyarova
- Institute of Cytology and Genetics SB RAS, Lavrentieva av. 10, Novosibirsk, 630090, Russia
| | - D I Berman
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, Magadan, 685000, Russia
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5
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Phillips JR, Nicolau GK, Ngwenya SS, Jackson EA, Womack MC. Habitat and Respiratory Strategy Effects on Hypoxia Performance in Anuran Tadpoles. Integr Comp Biol 2024; 64:336-353. [PMID: 38621716 DOI: 10.1093/icb/icae017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/02/2024] [Accepted: 04/08/2024] [Indexed: 04/17/2024] Open
Abstract
A critical component of animal conservation in a changing world is an understanding of the physiological resilience of animals to different conditions. In many aquatic animals, hypoxia (low environmental oxygen levels) is a regular occurrence, but the likelihood and severity of hypoxia vary across habitats. Fast-flowing, stream-like habitats are never hypoxic, so long as flow is maintained. Do animals from such habitats retain the capacity to survive hypoxic conditions? We use aquatic frog tadpoles to test the effects of natural habitat on performance in hypoxia in an experimental framework, finding that stream-living tadpoles have reduced performance in hypoxia. Tadpoles also vary in lung presence, with some species able to breathe air during hypoxia. We found that among lunged tadpoles, air-breathing rates increase in hypoxia in pond-living species but not stream-living species. Lung presence was also found to influence hypoxia performance, as lungless, stream-living tadpoles were found to be especially vulnerable to hypoxia, while pond-living, lungless tadpoles appeared largely resilient to hypoxia. We consider the ramifications of our findings on conservation outlooks and strategies for frogs and their tadpoles, suggesting that stream-living tadpoles, and especially lungless, stream-living tadpoles, may be particularly at risk to factors that reduce stream flow. Thus, a primary goal for conservation and management of species with stream-living tadpoles should be the maintenance of year-round streamflow, which oxygenates waters and prevents hypoxia.
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Affiliation(s)
| | | | - Shane S Ngwenya
- University of the Western Cape, Biodiversity and Conservation Biology, Cape Town, RSA 7535, South Africa
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6
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Kadamani KL, Rahnamaie-Tajadod R, Eaton L, Bengtsson J, Ojaghi M, Cheng H, Pamenter ME. What can naked mole-rats teach us about ameliorating hypoxia-related human diseases? Ann N Y Acad Sci 2024. [PMID: 39269277 DOI: 10.1111/nyas.15219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2024]
Abstract
Ameliorating the deleterious impact of systemic or tissue-level hypoxia or ischemia is key to preventing or treating many human diseases and pathologies. Usefully, environmental hypoxia is also a common challenge in many natural habitats; animals that are native to such hypoxic niches often exhibit strategies that enable them to thrive with limited O2 availability. Studying how such species have evolved to tolerate systemic hypoxia offers a promising avenue of discovery for novel strategies to mitigate the deleterious effects of hypoxia in human diseases and pathologies. Of particular interest are naked mole-rats, which are among the most hypoxia-tolerant mammals. Naked mole-rats that tolerate severe hypoxia in a laboratory setting are also protected against clinically relevant mimics of heart attack and stroke. The mechanisms that support this tolerance are currently being elucidated but results to date suggest that metabolic rate suppression, reprogramming of metabolic pathways, and mechanisms that defend against deleterious perturbations of cellular signaling pathways all provide layers of protection. Herein, we synthesize and discuss what is known regarding adaptations to hypoxia in the naked mole-rat cardiopulmonary system and brain, as these systems comprise both the primary means of delivering O2 to tissues and the most hypoxia-sensitive organs in mammals.
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Affiliation(s)
- Karen L Kadamani
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - John Bengtsson
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Mohammad Ojaghi
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Hang Cheng
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, 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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7
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Thomas PA, Kinsey ST. Hypoxia Tolerance of Two Killifish Species. Integr Comp Biol 2024:icae144. [PMID: 39238158 DOI: 10.1093/icb/icae144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 08/04/2024] [Accepted: 08/14/2024] [Indexed: 09/07/2024] Open
Abstract
Hypoxia tolerance in aquatic ectotherms involves a suite of behavioral and physiological responses at the organismal, tissue, and cellular levels. The current study evaluated two closely related killifish species (Fundulus heteroclitus, Fundulus majalis) to evaluate responses to acute moderate and acute severe hypoxia. Routine metabolic rate and loss of equilibrium were assessed, followed by analysis in skeletal muscle of markers of oxidative damage to proteins (2,4-DNPH), lipids (4-HNE), and DNA (8-OHdG), hypoxia signaling (HIF1α, HIF2α), cellular energy state (p-AMPK: AMPK), and protein degradation (Ubiquitin, LC3B, Calpain 2, Hsp70). Both species had a similar reduction in metabolic rate at low PO2. However, F. heteroclitus was the more hypoxia-tolerant species based on a lower PO2 at which there was loss of equilibrium, perhaps due in part to a lower oxygen demand at all oxygen tensions. Despite the differences in hypoxia tolerance between the species, skeletal muscle molecular markers were largely insensitive to hypoxia, and there were few differences in responses between the species. Thus, the metabolic depression observed at the whole animal level appears to limit perturbations in skeletal muscle in both species during the hypoxia treatments.
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Affiliation(s)
- Peyton A Thomas
- Department of Biology and Marine Biology, University of North Carolina at Wilmington, Wilmington, NC 28403, USA
| | - Stephen T Kinsey
- Department of Biology and Marine Biology, University of North Carolina at Wilmington, Wilmington, NC 28403, USA
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8
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Moreira DC, Hermes-Lima M. Dynamics of Redox Metabolism during Complete Metamorphosis of Insects: Insights from the Sunflower Caterpillar Chlosyne lacinia (Lepidoptera). Antioxidants (Basel) 2024; 13:959. [PMID: 39199204 PMCID: PMC11351957 DOI: 10.3390/antiox13080959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 08/01/2024] [Accepted: 08/06/2024] [Indexed: 09/01/2024] Open
Abstract
Complete insect metamorphosis requires substantial metabolic and physiological adjustments. Although oxidative stress has been implicated in metamorphosis, details on redox metabolism during larva-to-pupa and pupa-to-adult remain scarce. This study explores redox metabolism during metamorphosis of a lepidopteran (Chlosyne lacinia), focusing on core metabolism, antioxidant systems and oxidative stress. The larva-to-pupa transition was characterized by increased lactate dehydrogenase and glutathione peroxidase (GPX) activities, coupled with depletion of reduced glutathione (GSH), high disulfide-to-total-glutathione ratio (GSSG/tGSH), and increased lipid peroxidation. As metamorphosis progressed, metabolic enzyme activities, citrate synthase and glucose 6-phosphate dehydrogenase increased, indicating heightened oxidative metabolism associated with adult development. Concurrently, GSH and GPX levels returned to larval levels and GSSG/tGSH reached its most reduced state right before adult emergence. Adult emergence was marked by a further increase in oxidative metabolism, accompanied by redox imbalance and enhanced antioxidant mechanisms. These findings highlight a fluctuation in redox balance throughout metamorphosis, with periods of oxidative eustress followed by compensatory antioxidant responses. This study is the first to identify concurrent changes in metabolism, antioxidants, redox balance and oxidative stress throughout metamorphosis. Our findings extend knowledge on redox metabolism adjustments and highlight redox adaptations and oxidative stress as natural components of complete insect metamorphosis.
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Affiliation(s)
- Daniel C. Moreira
- Research Center in Morphology and Applied Immunology, Faculty of Medicine, University of Brasilia, Brasilia 70910-900, Brazil
- Cell Biology Department, Biological Sciences Institute, University of Brasilia, Brasilia 70910-900, Brazil;
| | - Marcelo Hermes-Lima
- Cell Biology Department, Biological Sciences Institute, University of Brasilia, Brasilia 70910-900, Brazil;
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9
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Christodoulides N, Urgiles VL, Guayasamin JM, Savage AE. Selection and Gene Duplication Associated With High-Elevation Diversification in Pristimantis, the Largest Terrestrial Vertebrate Genus. Genome Biol Evol 2024; 16:evae167. [PMID: 39109890 PMCID: PMC11342244 DOI: 10.1093/gbe/evae167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2024] [Indexed: 08/24/2024] Open
Abstract
The genus Pristimantis diversified in the tropical Andes mountains and is the most speciose genus of terrestrial vertebrates. Pristimantis are notable among frogs in that they thrive at high elevations (>2,000 m) and are direct developers without a tadpole stage. Despite their ecological significance, little is known about the genetic and physiological traits enabling their success. We conducted transcriptomic analysis on seven Pristimantis species sampled across elevations in the Ecuadorean Andes to explore three hypotheses for their success: (i) unique genes are under selection relative to all other frogs, (ii) common selection occurs across all direct developers, or (iii) common selection occurs across all high-elevation frog clades. Comparative analysis with 34 frog species revealed unique positive selection in Pristimantis genes related to aerobic respiration, hemostasis, signaling, cellular transportation of proteins and ions, and immunity. Additionally, we detected positive selection across all direct developers for genes associated with oxygenase activity and metal ion binding. While many genes under selection in Pristimantis were not positively selected in other high-elevation frog species, we identified some shared genes and pathways linked to lipid metabolism, innate immunity, and cellular redox processes. We observed more positive selection in duplicated- versus single-copy genes, while relaxed purifying selection was prevalent in single-copy genes. Notably, copy number of an innate immunity complement gene was positively correlated with Pristimantis species elevation. Our findings contribute novel insights into the genetic basis of adaptation in Pristimantis and provide a foundation for future studies on the evolutionary mechanisms leading to direct development and coping with high elevations.
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Affiliation(s)
| | - Veronica L Urgiles
- Department of Biology, University of Central Florida, Orlando, FL, USA
- Departamento de herpetologia, Instituto Nacional de Biodiversidad del Ecuador, Quito, Ecuador
| | - Juan M Guayasamin
- Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto Biósfera, Laboratorio de Biología Evolutiva, Universidad San Francisco de Quito USFQ, Quito, Ecuador
- Ingeniería en Biodiversidad y Recursos Genéticos, Centro de Biodiversidad y Cambio Climático BioCamb, Universidad Tecnológica Indoamérica, Quito, Ecuador
| | - Anna E Savage
- Department of Biology, University of Central Florida, Orlando, FL, USA
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10
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Xie R, Guo H, Luo Y, Huang W, Ruan Z, Liu W. New Insights into the Mechanism by Which the Pituitary Gland Copes with Hypoxia Stress Based on a Transcriptomic Analysis of Megalobrama amblycephala. Genes (Basel) 2024; 15:987. [PMID: 39202348 PMCID: PMC11353591 DOI: 10.3390/genes15080987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 07/18/2024] [Accepted: 07/24/2024] [Indexed: 09/03/2024] Open
Abstract
Hypoxia is a common environmental stressor in aquatic ecosystems, and during the cultivation process, Megalobrama amblycephala is prone to death because it is hypoxia-intolerant, which brings huge economic losses to farmers. The pituitary gland is a crucial endocrine gland in fish, and it is mainly involved in the secretion, storage, and regulation of hormones. In the present study, we compared the transcriptional responses to serious hypoxia in the pituitary gland among hypoxia-sensitive (HS) and hypoxia-tolerant (HT) M. amblycephala and a control group that received a normal oxygen supply (C0). The fish were categorized according to the time required to lose balance during a hypoxia treatment. A total of 129,251,170 raw reads were obtained. After raw sequence filtering, 43,461,745, 42,609,567, and 42,730,282 clean reads were obtained for the HS, HT, and C0 groups, respectively. A transcriptomic comparison revealed 1234 genes that were differentially expressed in C0 vs. HS, while 1646 differentially expressed genes were obtained for C0 vs. HT. In addition, the results for HS vs. HT showed that 367 upregulated and 41 downregulated differentially expressed genes were obtained for a total of 408 differentially expressed genes. A KEGG analysis of C0 vs. HS, C0 vs. HT, and HS vs. HT identified 315, 322, and 219 enriched pathways, respectively. Similar hypoxia-induced transcription patterns suggested that the downregulated DEGs and enriched pathways were related to pathways of neurodegeneration in multiple diseases, pathways in cancer, thermogenesis, microRNAs in cancer, diabetic cardiomyopathy, and renin secretion. However, in the upregulated DEGs, the PI3K-Akt signaling pathway (C0 vs. HS), microRNAs in cancer (C0 vs. HT), and HIF-1 signaling pathway (HS vs. HT) were significantly enriched. There is a lack of clarity regarding the role of the pituitary gland in hypoxic stress. These results not only provide new insights into the mechanism by which pituitary tissue copes with hypoxia stress in M. amblycephala but also offer a basis for breeding M. amblycephala with hypoxia-resistant traits.
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Affiliation(s)
- Ruilin Xie
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; (R.X.); (H.G.); (Y.L.)
| | - Huandi Guo
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; (R.X.); (H.G.); (Y.L.)
| | - Yuanyuan Luo
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; (R.X.); (H.G.); (Y.L.)
| | - Wen Huang
- Laboratory of Aquatic Sciences, Key Laboratory of Animal Nutrition and Feed Science in South China of Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China;
| | - Zhuohao Ruan
- Laboratory of Aquatic Sciences, Key Laboratory of Animal Nutrition and Feed Science in South China of Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China;
| | - Wensheng Liu
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; (R.X.); (H.G.); (Y.L.)
- Guangdong Province Engineering Research Centre of Aquatic Immunization and Aquaculture Health Techniques, South China Agricultural University, Guangzhou 510642, China
- University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, Guangzhou 510642, China
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11
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Borowiec BG, Firth BL, Craig PM. Oxygen consumption rate during recovery from loss of equilibrium induced by warming, hypoxia, or exhaustive exercise in rainbow darter (Etheostoma caeruleum). JOURNAL OF FISH BIOLOGY 2024; 105:23-33. [PMID: 38599790 DOI: 10.1111/jfb.15756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 03/03/2024] [Accepted: 04/01/2024] [Indexed: 04/12/2024]
Abstract
Animals routinely encounter environmental (e.g., high temperatures and hypoxia) as well as physiological perturbations (e.g., exercise and digestion) that may threaten homeostasis. However, comparing the relative threat or "disruptiveness" imposed by different stressors is difficult, as stressors vary in their mechanisms, effects, and timescales. We exploited the fact that several acute stressors can induce the loss of equilibrium (LOE) in fish to (i) compare the metabolic recovery profiles of three environmentally relevant stressors and (ii) test the concept that LOE could be used as a physiological calibration for the intensity of different stressors. We focused on Etheostoma caeruleum, a species that routinely copes with environmental fluctuations in temperature and oxygen and that relies on burst swimming to relocate and avoid predators, as our model. Using stop-flow (intermittent) respirometry, we tracked the oxygen consumption rate (MO2) as E. caeruleum recovered from LOE induced by hypoxia (PO2 at LOE), warming (critical thermal maximum, CTmax), or exhaustive exercise. Regardless of the stressor used, E. caeruleum recovered rapidly, returning to routine MO2 within ~3 h. Fish recovering from hypoxia and warming had similar maximum MO2, aerobic scopes, recovery time, and total excess post-hypoxia or post-warming oxygen consumption. Though exhaustive exercise induced a greater maximum MO2 and corresponding higher aerobic scope than warming or hypoxia, its recovery profile was otherwise similar to the other stressors, suggesting that "calibration" to a physiological state such as LOE may be a viable conceptual approach for investigators interested in questions related to multiple stressors, cross tolerance, and how animals cope with challenges to homeostasis.
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Affiliation(s)
| | - Britney L Firth
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Paul M Craig
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
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12
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Lai H, Bi S, Yi H, Li H, Wei X, Wang G, Guo D, Liu X, Chen J, Chen Q, Zhang Z, Liu S, Huang C, Lin L, Li G. Characteristics of demersal fish community structure during summer hypoxia in the Pearl River Estuary, China. Ecol Evol 2024; 14:e11722. [PMID: 38994211 PMCID: PMC11237343 DOI: 10.1002/ece3.11722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 06/20/2024] [Accepted: 06/26/2024] [Indexed: 07/13/2024] Open
Abstract
In recent decades, hypoxic areas have rapidly expanded worldwide in estuaries and coastal zones. The Pearl River Estuary (PRE), one of China's largest estuaries, experiences frequent seasonal hypoxia due to intense human activities and eutrophication. However, the ecological effects of hypoxia in the PRE, particularly on fish communities, remain unclear. To explore these effects, we collected fish community and environmental data in July 2021 during the summer hypoxia development period. The results revealed that bottom-layer dissolved oxygen (DO) in the PRE ranged from 0.08 to 5.71 mg/L, with extensive hypoxic zones (DO ≤ 2 mg/L) observed. Hypoxia has varied effects on fish community composition, distribution, species, and functional diversity in the PRE. A total of 104 fish species were collected in this study, with approximately 30 species (28.6%) exclusively found in hypoxic areas. Species responses to hypoxia varied: species such as Sardinella zunasi, Coilia mystus, and Nuchequula nuchalis were sensitive, while Decapterus maruadsi, Siganus fuscescens, and Lagocephalus spadiceus showed higher tolerance. Within the hypoxia area, dissolved oxygen was the main limiting factor for fish community diversity. Functional diversity (FDiv) decreased with higher dissolved oxygen levels, indicating a potential shift in the functional traits and ecological roles of fish species in response to changing oxygen conditions. Further analysis demonstrated that dissolved oxygen had a significantly stronger effect on fish community structure at hypoxic sites than in the whole PRE. Moreover, other environmental variables also had significant effects on the fish community structure and interacted with dissolved oxygen in the hypoxia area. These findings suggest that maintaining sufficient dissolved oxygen levels is essential for sustaining fish communities and ecosystem health in the PRE. This study provides novel insights into the effects of hypoxia on fish communities in estuarine ecosystems and has significant implications for the ecological health and management of the PRE.
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Affiliation(s)
- Han Lai
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)GuangzhouChina
| | - Sheng Bi
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
- Bureau of HydrologyPearl River Water Resources Commission of the Ministry of Water ResourcesGuangzhouChina
| | - Huadong Yi
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Haiyang Li
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Xuchong Wei
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Gongpei Wang
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Dingli Guo
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Xuange Liu
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Jiahui Chen
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Qiuxian Chen
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Zhilun Zhang
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Shuang Liu
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Chenlei Huang
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Li Lin
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
| | - Guifeng Li
- State Key Laboratory of BiocontrolSouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang BaySchool of Life SciencesSun Yat‐Sen UniversityGuangzhouChina
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13
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Cortes S, Farhat E, Talarico G, Mennigen JA. The dynamic transcriptomic response of the goldfish brain under chronic hypoxia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2024; 50:101233. [PMID: 38608489 DOI: 10.1016/j.cbd.2024.101233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/26/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024]
Abstract
Oxygen is essential to fuel aerobic metabolism. Some species evolved mechanisms to tolerate periods of severe hypoxia and even anoxia in their environment. Among them, goldfish (Carassius auratus) are unique, in that they do not enter a comatose state under severely hypoxic conditions. There is thus significant interest in the field of comparative physiology to uncover the mechanistic basis underlying hypoxia tolerance in goldfish, with a particular focus on the brain. Taking advantage of the recently published and annotated goldfish genome, we profile the transcriptomic response of the goldfish brain under normoxic (21 kPa oxygen saturation) and, following gradual reduction, constant hypoxic conditions after 1 and 4 weeks (2.1 kPa oxygen saturation). In addition to analyzing differentially expressed protein-coding genes and enriched pathways, we also profile differentially expressed microRNAs (miRs). Using in silico approaches, we identify possible miR-mRNA relationships. Differentially expressed transcripts compared to normoxia were either common to both timepoints of hypoxia exposure (n = 174 mRNAs; n = 6 miRs), or exclusive to 1-week (n = 441 mRNAs; n = 23 miRs) or 4-week hypoxia exposure (n = 491 mRNAs; n = 34 miRs). Under chronic hypoxia, an increasing number of transcripts, including those of paralogous genes, was downregulated over time, suggesting a decrease in transcription. GO-terms related to the vascular system, oxidative stress, stress signalling, oxidoreductase activity, nucleotide- and intermediary metabolism, and mRNA posttranscriptional regulation were found to be enriched under chronic hypoxia. Known 'hypoxamiRs', such as miR-210-3p/5p, and miRs such as miR-29b-3p likely contribute to posttranscriptional regulation of these pathways under chronic hypoxia in the goldfish brain.
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Affiliation(s)
- S Cortes
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada; Laboratorio de Oncogenómica, Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City 14610, Mexico
| | - E Farhat
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada; Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Ggm Talarico
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada
| | - J A Mennigen
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada.
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14
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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 PMCID: PMC11166464 DOI: 10.1242/jeb.247537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [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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15
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Zhao C, Song Y, Zhang G, Zhang K, Yin S, Ji J. Multi-omics analysis identifies sex-specific hepatic protein-metabolite networks in yellow catfish (Pelteobagrus fulvidraco) exposed to chronic hypoxia. Int J Biol Macromol 2024; 268:131892. [PMID: 38677698 DOI: 10.1016/j.ijbiomac.2024.131892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 04/29/2024]
Abstract
Hypoxia disrupts the endocrine system of teleosts. The liver plays important roles in the endocrine system, energy storage, and metabolic processes. The aim of this study was to investigate the sex-specific hepatic response of yellow catfish under chronic hypoxia at the multi-omics level. Common hepatic responses in both sexes included the HIF-1 signaling pathway, glycolysis/gluconeogenesis, and steroid biosynthesis. Hypoxia dysregulated primary bile acid biosynthesis, lipid metabolism, and vitellogenin levels in female fish. Endoplasmic reticulum function in females also tended to be disrupted by hypoxia, as evidenced by significantly enriched pathways, including ribosome, protein processing in the endoplasmic reticulum, and RNA degradation. Other pathways, including the TCA cycle, oxidative phosphorylation, and Parkinson's and Huntington's disease, were highly enriched by hypoxia in male fish, suggesting that mitochondrial function was dysregulated. In both sexes of yellow catfish, the cell cycle was arrested and apoptosis was inhibited under chronic hypoxia. Multi-omics suggested that SLC2A5, CD209, LGMN, and NEDD8 served as sex-specific markers in these fish under chronic hypoxia. Our results provide insights into hepatic adaptation to chronic hypoxia and facilitate our understanding of sex-specific responses in fish.
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Affiliation(s)
- Cheng Zhao
- College of Marine Science and Engineering, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, China; Co-Innovation Center for Marine Bio-Industry Technology, Lian Yungang, Jiangsu, China
| | - Yufeng Song
- College of Marine Science and Engineering, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Guosong Zhang
- School of Agriculture and Bioengineering, Heze University, Heze, Shandong, China
| | - Kai Zhang
- College of Marine Science and Engineering, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, China; Co-Innovation Center for Marine Bio-Industry Technology, Lian Yungang, Jiangsu, China
| | - Shaowu Yin
- College of Marine Science and Engineering, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, China; Co-Innovation Center for Marine Bio-Industry Technology, Lian Yungang, Jiangsu, China.
| | - Jie Ji
- College of Marine Science and Engineering, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, China; Co-Innovation Center for Marine Bio-Industry Technology, Lian Yungang, Jiangsu, China.
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16
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Suganthan H, Stefano DD, Buck LT. Alfaxalone is an effective anesthetic for the electrophysiological study of anoxia-tolerance mechanisms in western painted turtle pyramidal neurons. PLoS One 2024; 19:e0298065. [PMID: 38626211 PMCID: PMC11020846 DOI: 10.1371/journal.pone.0298065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/17/2024] [Indexed: 04/18/2024] Open
Abstract
Anoxia in the mammalian brain leads to hyper-excitability and cell death; however, this cascade of events does not occur in the anoxia-tolerant brain of the western painted turtle, Chrysemys picta belli. The painted turtle has become an important anoxia-tolerant model to study brain, heart, and liver function in the absence of oxygen, but being anoxia-tolerant likely means that decapitation alone is not a suitable method of euthanasia. Many anesthetics have long-term effects on ion channels and are not appropriate for same day experimentation. Using whole-cell electrophysiological techniques, we examine the effects of the anesthetic, Alfaxalone, on pyramidal cell action potential amplitude, threshold, rise and decay time, width, frequency, whole cell conductance, and evoked GABAA receptors currents to determine if any of these characteristics are altered with the use of Alfaxalone for animal sedation. We find that Alfaxalone has no long-term impact on action potential parameters or whole-cell conductance. When acutely applied to naïve tissue, Alfaxalone did lengthen GABAA receptor current decay rates by 1.5-fold. Following whole-animal sedation with Alfaxalone, evoked whole cell GABAA receptor current decay rates displayed an increasing trend with 1 and 2 hours after brain sheet preparation, but showed no significant change after a 3-hour washout period. Therefore, we conclude that Alfaxalone is a suitable anesthetic for same day use in electrophysiological studies in western painted turtle brain tissue.
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Affiliation(s)
- Haushe Suganthan
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Domenic Di Stefano
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Leslie T. Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
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17
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Jannat R, Zahangir MM, Naziat A, Majharul Islam SM, Abdelazim AM, Mahboub HH, Shahjahan M. Hypoxia alters the upper thermal limits and blood physiology in zebrafish, Danio rerio. J Therm Biol 2024; 121:103837. [PMID: 38552447 DOI: 10.1016/j.jtherbio.2024.103837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/27/2024] [Accepted: 02/27/2024] [Indexed: 05/26/2024]
Abstract
Hypoxic aquatic environments occur more frequently as a result of climate change, thereby exerting challenges on the physiological and metabolic functions of aquatic animals. In this study, a model fish, zebrafish (Danio rerio) was used to observe the climate-induced hypoxic effect on the upper thermal limit (critical thermal maximum; CTmax), hemoglobin, and blood glucose levels, and abnormalities of erythrocytes at cellular and nuclear level. The value of CTmax decreased significantly under hypoxia (39.10 ± 0.96 °C) compared to normoxia (43.70 ± 0.91 °C). At CTmax, hemoglobin levels were much lower (9.33 ± 0.60 g/dL) and blood glucose levels were significantly higher (194.20 ± 11.33 mg/L) under hypoxia than they were under normoxia and at the beginning of the experiment. Increased frequencies of abnormalities in the erythrocytes at both cellular (fusion, twin, elongated, spindle and tear drop shaped) and nuclear (micronucleus, karyopyknosis, binuclei, nuclear degeneration and notched nuclei) levels were also found under hypoxia compared to normoxia. These results suggest that hypoxic conditions significantly alter the temperature tolerance and subsequent physiology in zebrafish. Our findings will aid in the development of effective management techniques for aquatic environments with minimum oxygen availability.
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Affiliation(s)
- Rayeda Jannat
- Laboratory of Fish Ecophysiology, Department of Fisheries Management, Bangladesh Agricultural University, Mymemsingh, 2202, Bangladesh.
| | - Md Mahiuddin Zahangir
- Department of Fish Biology and Biotechnology, Chattogram Veterinary and Animal Sciences University, Chattogram, 4225, Bangladesh.
| | - Azmaien Naziat
- Department of Fish Biology and Biotechnology, Chattogram Veterinary and Animal Sciences University, Chattogram, 4225, Bangladesh.
| | - S M Majharul Islam
- Laboratory of Fish Ecophysiology, Department of Fisheries Management, Bangladesh Agricultural University, Mymemsingh, 2202, Bangladesh.
| | - Aaser M Abdelazim
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, University of Bisha, Bisha, 67714, P.O. Box 255, Saudi Arabia.
| | - Heba H Mahboub
- Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, PO Box 44519, Zagazig, 4511, Sharkia, Egypt.
| | - Md Shahjahan
- Laboratory of Fish Ecophysiology, Department of Fisheries Management, Bangladesh Agricultural University, Mymemsingh, 2202, Bangladesh.
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18
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Turingan MJ, Li T, Wright J, Sharma A, Ding K, Khan S, Lee B, Grewal SS. Hypoxia delays steroid-induced developmental maturation in Drosophila by suppressing EGF signaling. PLoS Genet 2024; 20:e1011232. [PMID: 38669270 PMCID: PMC11098494 DOI: 10.1371/journal.pgen.1011232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 05/16/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
Animals often grow and develop in unpredictable environments where factors like food availability, temperature, and oxygen levels can fluctuate dramatically. To ensure proper sexual maturation into adulthood, juvenile animals need to adapt their growth and developmental rates to these fluctuating environmental conditions. Failure to do so can result in impaired maturation and incorrect body size. Here we describe a mechanism by which Drosophila larvae adapt their development in low oxygen (hypoxia). During normal development, larvae grow and increase in mass until they reach critical weight (CW), after which point a neuroendocrine circuit triggers the production of the steroid hormone ecdysone from the prothoracic gland (PG), which promotes maturation to the pupal stage. However, when raised in hypoxia (5% oxygen), larvae slow their growth and delay their maturation to the pupal stage. We find that, although hypoxia delays the attainment of CW, the maturation delay occurs mainly because of hypoxia acting late in development to suppress ecdysone production. This suppression operates through a distinct mechanism from nutrient deprivation, occurs independently of HIF-1 alpha and does not involve dilp8 or modulation of Ptth, the main neuropeptide that initiates ecdysone production in the PG. Instead, we find that hypoxia lowers the expression of the EGF ligand, spitz, and that the delay in maturation occurs due to reduced EGFR/ERK signaling in the PG. Our study sheds light on how animals can adjust their development rate in response to changing oxygen levels in their environment. Given that hypoxia is a feature of both normal physiology and many diseases, our findings have important implications for understanding how low oxygen levels may impact animal development in both normal and pathological situations.
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Affiliation(s)
- Michael J. Turingan
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Tan Li
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Jenna Wright
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Abhishek Sharma
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Kate Ding
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Shahoon Khan
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Byoungchun Lee
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
| | - Savraj S. Grewal
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Alberta, Canada
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19
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Di Stefano D, Suganthan H, Buck L. Alfaxalone does not have long-term effects on goldfish pyramidal neuron action potential properties or GABA A receptor currents. FEBS Open Bio 2024; 14:555-573. [PMID: 38342633 PMCID: PMC10988724 DOI: 10.1002/2211-5463.13777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/30/2023] [Accepted: 01/31/2024] [Indexed: 02/13/2024] Open
Abstract
Anesthetics have varying physiological effects, but most notably alter ion channel kinetics. Alfaxalone is a rapid induction and washout neuroactive anesthetic, which potentiates γ-aminobutyric acid (GABA)-activated GABAA receptor (GABAA-R) currents. This study aims to identify any long-term effects of alfaxalone sedation on pyramidal neuron action potential and GABAA-R properties, to determine if its impact on neuronal function can be reversed in a sufficiently short timeframe to allow for same-day electrophysiological studies in goldfish brain. The goldfish (Carassius auratus) is an anoxia-tolerant vertebrate and is a useful model to study anoxia tolerance mechanisms. The results show that alfaxalone sedation did not significantly impact action potential properties. Additionally, the acute application of alfaxalone onto naive brain slices caused the potentiation of whole-cell GABAA-R current decay time and area under the curve. Following whole-animal sedation with alfaxalone, a 3-h wash of brain slices in alfaxalone-free saline, with saline exchanged every 30 min, was required to remove any potentiating impact of alfaxalone on GABAA-R whole-cell currents. These results demonstrate that alfaxalone is an effective anesthetic for same-day electrophysiological experiments with goldfish brain slices.
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Affiliation(s)
| | - Haushe Suganthan
- Department of Cell and Systems BiologyUniversity of TorontoCanada
| | - Leslie Buck
- Department of Cell and Systems BiologyUniversity of TorontoCanada
- Department of Ecology and Evolutionary BiologyUniversity of TorontoCanada
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20
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Filice M, Gattuso A, Imbrogno S, Mazza R, Amelio D, Caferro A, Agnisola C, Icardo JM, Cerra MC. Functional, structural, and molecular remodelling of the goldfish (Carassius auratus) heart under moderate hypoxia. FISH PHYSIOLOGY AND BIOCHEMISTRY 2024; 50:667-685. [PMID: 38198074 PMCID: PMC11021278 DOI: 10.1007/s10695-024-01297-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 01/01/2024] [Indexed: 01/11/2024]
Abstract
The goldfish (Carassius auratus) is known for its physiologic ability to survive even long periods of oxygen limitation (hypoxia), adapting the cardiac performance to the requirements of peripheral tissue perfusion. We here investigated the effects of short-term moderate hypoxia on the heart, focusing on ventricular adaptation, in terms of hemodynamics and structural traits. Functional evaluations revealed that animals exposed to 4 days of environmental hypoxia increased the hemodynamic performance evaluated on ex vivo cardiac preparations. This was associated with a thicker and more vascularized ventricular compact layer and a reduced luminal lacunary space. Compared to normoxic animals, ventricular cardiomyocytes of goldfish exposed to hypoxia showed an extended mitochondrial compartment and a modulation of proteins involved in mitochondria dynamics. The enhanced expression of the pro-fission markers DRP1 and OMA1, and the modulation of the short and long forms of OPA1, suggested a hypoxia-related mitochondria fission. Our data propose that under hypoxia, the goldfish heart undergoes a structural remodelling associated with a potentiated cardiac activity. The energy demand for the highly performant myocardium is supported by an increased number of mitochondria, likely occurring through fission events.
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Affiliation(s)
- Mariacristina Filice
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Alfonsina Gattuso
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Sandra Imbrogno
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy.
| | - Rosa Mazza
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Daniela Amelio
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Alessia Caferro
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Claudio Agnisola
- Department of Biological Sciences, University of Naples Federico II, Naples, Italy
| | - José Manuel Icardo
- Department of Anatomy and Cell Biology, University of Cantabria, Santander, Spain
| | - Maria Carmela Cerra
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
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21
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Bundgaard A, Borowiec BG, Lau GY. Are reactive oxygen species always bad? Lessons from hypoxic ectotherms. J Exp Biol 2024; 227:jeb246549. [PMID: 38533673 DOI: 10.1242/jeb.246549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Oxygen (O2) is required for aerobic energy metabolism but can produce reactive oxygen species (ROS), which are a wide variety of oxidant molecules with a range of biological functions from causing cell damage (oxidative distress) to cell signalling (oxidative eustress). The balance between the rate and amount of ROS generated and the capacity for scavenging systems to remove them is affected by several biological and environmental factors, including oxygen availability. Ectotherms, and in particular hypoxia-tolerant ectotherms, are hypothesized to avoid oxidative damage caused by hypoxia, although it is unclear whether this translates to an increase in ecological fitness. In this Review, we highlight the differences between oxidative distress and eustress, the current mechanistic understanding of the two and how they may affect ectothermic physiology. We discuss the evidence of occurrence of oxidative damage with hypoxia in ectotherms, and that ectotherms may avoid oxidative damage through (1) high levels of antioxidant and scavenging systems and/or (2) low(ering) levels of ROS generation. We argue that the disagreements in the literature as to how hypoxia affects antioxidant enzyme activity and the variable metabolism of ectotherms makes the latter strategy more amenable to ectotherm physiology. Finally, we argue that observed changes in ROS production and oxidative status with hypoxia may be a signalling mechanism and an adaptive strategy for ectotherms encountering hypoxia.
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Affiliation(s)
- Amanda Bundgaard
- University of Cologne, CECAD, Joseph-Stelzmann-Straße 26, DE-50931 Köln, Germany
- Aarhus University, Department of Biology, CF Moellers Alle 3, DK-8000 Aarhus C, Denmark
| | - Brittney G Borowiec
- Wilfrid Laurier University, Department of Biology, 75 University Ave. W., Waterloo, ON, Canada, N2L 3C5
| | - Gigi Y Lau
- University of British Columbia, Department of Zoology, 6270 University Blvd, Vancouver, BC, Canada, V6T 1Z4
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22
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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] [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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23
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Hasan MM, Sekiya R, Zhang X, Yassouf MY, Li TS. Comparison of hypoxia- and hyperoxia-induced alteration of epigene expression pattern in lungs of Pleurodeles waltl and Mus musculus. PLoS One 2024; 19:e0299661. [PMID: 38416753 PMCID: PMC10901355 DOI: 10.1371/journal.pone.0299661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/12/2024] [Indexed: 03/01/2024] Open
Abstract
Epigenetics is an emerging field of research because of its involvement in susceptibility to diseases and aging. Hypoxia and hyperoxia are known to be involved widely in various pathophysiologies. Here, we compared the differential epigene expression pattern between Pleurodeles waltl and Mus musculus (commonly known as Iberian ribbed newt and mouse, respectively) exposed to hypoxia and hyperoxia. Adult healthy newts and mice were exposed to normobaric hypoxia (8% O2) and hyperoxia (80% O2) for 2 hours. We collected the lungs and analyzed the expression of hypoxia-inducible factor 1 alpha (Hif1α) and several key epigenes from DNA methyltransferase (DNMT) family, histone deacetylase (HDAC) family, and methyl-CpG binding domain (MBD) family. The exposure to hypoxia significantly increased the mRNA levels of DNA methyltransferase 3 alpha (Dnmt3α), methyl-CpG binding domain protein 2 (Mbd2), Mbd3, and histone deacetylase 2 (Hdac2) in lungs of newts, but decreased the mRNA levels of DNA methyltransferase 1 (Dnmt1) and Dnmt3α in lungs of mice. The exposure to hyperoxia did not significantly change the expression of any gene in either newts or mice. The differential epigene expression pattern in response to hypoxia between newts and mice may provide novel insights into the prevention and treatment of disorders developed due to hypoxia exposure.
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Affiliation(s)
- Md. Mahmudul Hasan
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Reiko Sekiya
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Xu Zhang
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Mhd Yousuf Yassouf
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Tao-Sheng Li
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
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24
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Filice M, Caferro A, Gattuso A, Sperone E, Agnisola C, Faggio C, Cerra MC, Imbrogno S. Effects of environmental hypoxia on the goldfish skeletal muscle: Focus on oxidative status and mitochondrial dynamics. JOURNAL OF CONTAMINANT HYDROLOGY 2024; 261:104299. [PMID: 38237486 DOI: 10.1016/j.jconhyd.2024.104299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 01/02/2024] [Accepted: 01/11/2024] [Indexed: 02/13/2024]
Abstract
The skeletal muscle is a highly plastic tissue. Its ability to respond to external stimuli and challenges allows it to face the functional needs of the organism. In the goldfish Carassius auratus, a model of hypoxia resistance, exposure to reduced oxygen is accompanied by an improvement of the swimming performance, relying on a sustained contractile behavior of the skeletal muscle. At the moment, limited information is available on the mechanisms underlying these responses. We here evaluated the effects of short- (4 days) and long- (20 days) term exposure to moderate water hypoxia on the goldfish white skeletal muscle, focusing on oxidative status and mitochondrial dynamics. No differences in lipid peroxidation, measured as 2-thiobarbituric acid-reacting substances (TBARS), and oxidatively modified proteins (OMP) were detected in animals exposed to hypoxia with respect to their normoxic counterparts. Exposure to short-term hypoxia was characterized by an enhanced SOD activity and expression, paralleled by increased levels of Nrf2, a regulator of the antioxidant cell response, and HSP70, a chaperone also acting as a redox sensor. The expression of markers of mitochondrial biogenesis (TFAM) and abundance (VDAC) and of the mtDNA/nDNA ratio was similar under normoxia and under both short- and long-term hypoxia, thus excluding a rearrangement of the mitochondrial apparatus. Only an increase of PGC1α (a transcription factor involved in mitochondrial dynamics) was detected after 20 days of hypoxia. Our results revealed novel aspects of the molecular mechanisms that in the goldfish skeletal muscle may sustain the response to hypoxia, thus contributing to adequate tissue function to organism requirements.
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Affiliation(s)
- Mariacristina Filice
- Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy
| | - Alessia Caferro
- Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy
| | - Alfonsina Gattuso
- Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
| | - Emilio Sperone
- Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy
| | - Claudio Agnisola
- Dept. of Biological Sciences, University of Naples Federico II, Napoli, Italy
| | - Caterina Faggio
- Dept. of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy; Dept. of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy.
| | - Maria Carmela Cerra
- Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy
| | - Sandra Imbrogno
- Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy
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25
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Souchet J, Josserand A, Darnet E, Le Chevalier H, Trochet A, Bertrand R, Calvez O, Martinez-Silvestre A, Guillaume O, Mossoll-Torres M, Pottier G, Philippe H, Aubret F, Gangloff EJ. Embryonic and juvenile snakes (Natrix maura, Linnaeus 1758) compensate for high elevation hypoxia via shifts in cardiovascular physiology and metabolism. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:1102-1115. [PMID: 37723946 DOI: 10.1002/jez.2756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 07/30/2023] [Accepted: 08/30/2023] [Indexed: 09/20/2023]
Abstract
The colonization of novel environments requires a favorable response to conditions never, or rarely, encountered in recent evolutionary history. For example, populations colonizing upslope habitats must cope with lower atmospheric pressure at elevation, and thus reduced oxygen availability. The embryo stage in oviparous organisms is particularly susceptible, given its lack of mobility and limited gas exchange via diffusion through the eggshell and membranes. Especially little is known about responses of Lepidosaurian reptiles to reduced oxygen availability. To test the role of physiological plasticity during early development in response to high elevation hypoxia, we performed a transplant experiment with the viperine snake (Natrix maura, Linnaeus 1758). We maintained gravid females originating from low elevation populations (432 m above sea level [ASL]-normoxia) at both the elevation of origin and high elevation (2877 m ASL-extreme high elevation hypoxia; approximately 72% oxygen availability relative to sea level), then incubated egg clutches at both low and high elevation. Regardless of maternal exposure to hypoxia during gestation, embryos incubated at extreme high elevation exhibited altered developmental trajectories of cardiovascular function and metabolism across the incubation period, including a reduction in late-development egg mass. This physiological response may have contributed to the maintenance of similar incubation duration, hatching success, and hatchling body size compared to embryos incubated at low elevation. Nevertheless, after being maintained in hypoxia, juveniles exhibit reduced carbon dioxide production relative to oxygen consumption, suggesting altered energy pathways compared to juveniles maintained in normoxia. These findings highlight the role of physiological plasticity in maintaining rates of survival and fitness-relevant phenotypes in novel environments.
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Affiliation(s)
- Jérémie Souchet
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | - Alicia Josserand
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | - Elodie Darnet
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | - Hugo Le Chevalier
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | - Audrey Trochet
- Société Herpétologique de France, Muséum National d'Histoire Naturelle, Paris, France
| | - Romain Bertrand
- Laboratoire Évolution et Diversité Biologique (UMR CNRS 5174), Université de Toulouse III Paul Sabatier, IRD, Toulouse, France
| | - Olivier Calvez
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | | | - Olivier Guillaume
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | | | | | - Hervé Philippe
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
| | - Fabien Aubret
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
- School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Eric J Gangloff
- Station d'Ecologie Théorique et Expérimentale (UAR CNRS 2029), Moulis, France
- Department of Biological Sciences, Ohio Wesleyan University, Delaware, Ohio, USA
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26
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Shekhovtsov SV, Bulakhova NA, Tsentalovich YP, Zelentsova EA, Osik NA, Meshcheryakova EN, Poluboyarova TV, Berman DI. Metabolomic Profiling Reveals Differences in Hypoxia Response between Far Eastern and Siberian Frogs. Animals (Basel) 2023; 13:3349. [PMID: 37958105 PMCID: PMC10647746 DOI: 10.3390/ani13213349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/08/2023] [Accepted: 10/20/2023] [Indexed: 11/15/2023] Open
Abstract
Anoxia is a significant challenge for most animals, as it can lead to tissue damage and death. Among amphibians, the Siberian frog Rana amurensis is the only known species capable of surviving near-zero levels of oxygen in water for a prolonged period. In this study, we aimed to compare metabolomic profiles of the liver, brain, and heart of the Siberian frog exposed to long-term oxygen deprivation (approximately 0.2 mg/L water) with those of the susceptible Far Eastern frog (Rana dybowskii) subjected to short-term hypoxia to the limits of its tolerance. One of the most pronounced features was that the organs of the Far Eastern frog contained more lactate than those of the Siberian frog despite a much shorter exposure time. The amounts of succinate were similar between the two species. Interestingly, glycerol and 2,3-butanediol were found to be significantly accumulated under hypoxia in the Siberian frog, but not in the Far Eastern frog. The role and biosynthesis of these substances are still unclear, but they are most likely formed in certain side pathways of glycolysis. Based on the obtained data, we suggest a pathway for metabolic changes in the Siberian frog under anoxia.
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Affiliation(s)
- Sergei V. Shekhovtsov
- Institute of Cytology and Genetics SB RAS, Lavrentieva av. 10, 630090 Novosibirsk, Russia;
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, 685000 Magadan, Russia; (N.A.B.); (E.N.M.); (D.I.B.)
| | - Nina A. Bulakhova
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, 685000 Magadan, Russia; (N.A.B.); (E.N.M.); (D.I.B.)
| | - Yuri P. Tsentalovich
- International Tomography Center SB RAS, Institutskaya 3a, 630090 Novosibirsk, Russia; (Y.P.T.); (E.A.Z.); (N.A.O.)
| | - Ekaterina A. Zelentsova
- International Tomography Center SB RAS, Institutskaya 3a, 630090 Novosibirsk, Russia; (Y.P.T.); (E.A.Z.); (N.A.O.)
| | - Nataliya A. Osik
- International Tomography Center SB RAS, Institutskaya 3a, 630090 Novosibirsk, Russia; (Y.P.T.); (E.A.Z.); (N.A.O.)
| | - Ekaterina N. Meshcheryakova
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, 685000 Magadan, Russia; (N.A.B.); (E.N.M.); (D.I.B.)
| | | | - Daniil I. Berman
- Institute of the Biological Problems of the North FEB RAS, Portovaya 18, 685000 Magadan, Russia; (N.A.B.); (E.N.M.); (D.I.B.)
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27
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Bueschke N, Amaral-Silva L, Hu M, Alvarez A, Santin JM. Plasticity in the functional properties of NMDA receptors improves network stability during severe energy stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.19.524811. [PMID: 36711958 PMCID: PMC9882286 DOI: 10.1101/2023.01.19.524811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Brain energy stress leads to neuronal hyperexcitability followed by a rapid loss of function and cell death. In contrast, the frog brainstem switches into a state of extreme metabolic resilience that allows them to maintain motor function during hypoxia as they emerge from hibernation. NMDA receptors (NMDARs) are Ca2+-permeable glutamate receptors that contribute to the loss of homeostasis during hypoxia. Therefore, we hypothesized that hibernation leads to plasticity that reduces the role of NMDARs within neural networks to improve function during energy stress. To test this, we assessed a circuit with a large involvement of NMDAR synapses, the brainstem respiratory network of female bullfrogs, Lithobates catesbeianus. Contrary to our expectations, hibernation did not alter the role of NMDARs in generating network output, nor did it affect the amplitude, kinetics, and hypoxia sensitivity of NMDAR currents. Instead, hibernation strongly reduced NMDAR Ca2+ permeability and enhanced desensitization during repetitive stimulation. Under severe hypoxia, the normal NMDAR profile caused network hyperexcitability within minutes, which was mitigated by blocking NMDARs. After hibernation, the modified complement of NMDARs protected against hyperexcitability, as disordered output did not occur for at least one hour in hypoxia. These findings uncover state-dependence in the plasticity of NMDARs, whereby multiple changes to receptor function improve neural performance during energy stress without interfering with its normal role during healthy activity.
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Affiliation(s)
| | | | - Min Hu
- University of North Carolina-Greensboro, Greensboro, NC 27402
| | - Alvaro Alvarez
- University of North Carolina-Greensboro, Greensboro, NC 27402
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28
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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] [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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29
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Falfushynska H, Sokolova IM. Intermittent hypoxia differentially affects metabolic and oxidative stress responses in two species of cyprinid fish. Biol Open 2023; 12:bio060069. [PMID: 37670684 PMCID: PMC10537972 DOI: 10.1242/bio.060069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 08/24/2023] [Indexed: 09/07/2023] Open
Abstract
Oxygen fluctuations are common in freshwater habitats and aquaculture and can impact ecologically and economically important species of fish like cyprinids. To gain insight into the physiological responses to oxygen fluctuations in two common cyprinid species, we evaluated the impact of short-term intermittent hypoxia on oxidative stress and metabolic parameters (including levels of prooxidants and oxidative lesions, antioxidants, mitochondrial enzyme activities, mitochondrial swelling, markers of apoptosis, autophagy and cytotoxicity) in silver carp Hypophthalmichthys molitrix and gibel carp Carassius gibelio. During hypoxia, gibel carp showed higher baseline levels of antioxidants and less pronounced changes in oxidative and metabolic biomarkers in the tissues than silver carp. Reoxygenation led to a strong shift in metabolic and redox-related parameters and tissue damage, indicating high cost of post-hypoxic recovery in both species. Species-specific differences were more strongly associated with oxidative stress status, whereas metabolic indices and nitrosative stress parameters were more relevant to the response to hypoxia-reoxygenation. Overall, regulation of energy metabolism appears more critical than the regulation of antioxidants in the response to oxygen deprivation in the studied species. Further research is needed to establish whether prioritizing metabolic over redox regulation during hypoxia-reoxygenation stress is common in freshwater cyprinids.
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Affiliation(s)
- Halina Falfushynska
- Department of Marine Biology, Institute for Biological Sciences, University of Rostock, Rostock 18059, Germany
- Department of Electrical, Mechanical and Industrial Engineering, Anhalt University for Applied Sciences, Köthen 06366, Germany
| | - Inna M. Sokolova
- Department of Marine Biology, Institute for Biological Sciences, University of Rostock, Rostock 18059, Germany
- Department of Maritime Systems, Interdisciplinary Faculty, University of Rostock, Rostock 18059, Germany
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30
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Prag HA, Murphy MP, Krieg T. Preventing mitochondrial reverse electron transport as a strategy for cardioprotection. Basic Res Cardiol 2023; 118:34. [PMID: 37639068 PMCID: PMC10462584 DOI: 10.1007/s00395-023-01002-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/04/2023] [Accepted: 08/06/2023] [Indexed: 08/29/2023]
Abstract
In the context of myocardial infarction, the burst of superoxide generated by reverse electron transport (RET) at complex I in mitochondria is a crucial trigger for damage during ischaemia/reperfusion (I/R) injury. Here we outline the necessary conditions for superoxide production by RET at complex I and how it can occur during reperfusion. In addition, we explore various pathways that are implicated in generating the conditions for RET to occur and suggest potential therapeutic strategies to target RET, aiming to achieve cardioprotection.
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Affiliation(s)
- Hiran A Prag
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK.
| | - Michael P Murphy
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK.
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - Thomas Krieg
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK.
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31
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Harford AR, Devaux JBL, Hickey AJR. Dynamic defence? Intertidal triplefin species show better maintenance of mitochondrial membrane potential than subtidal species at low oxygen pressures. J Exp Biol 2023; 226:jeb245926. [PMID: 37498237 DOI: 10.1242/jeb.245926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/14/2023] [Indexed: 07/28/2023]
Abstract
Oxygen is essential for most eukaryotic lifeforms, as it supports mitochondrial oxidative phosphorylation to supply ∼90% of cellular adenosine triphosphate (ATP). Fluctuations in O2 present a major stressor, with hypoxia leading to a cascade of detrimental physiological changes that alter cell operations and ultimately induce death. Nonetheless, some species episodically tolerate near-anoxic environments, and have evolved mechanisms to sustain function even during extended hypoxic periods. While mitochondria are pivotal in central metabolism, their role in hypoxia tolerance remains ill defined. Given the vulnerability of the brain to hypoxia, mitochondrial function was tested in brain homogenates of three closely related triplefin species with varying degrees of hypoxia tolerance (Bellapiscis medius, Forsterygion lapillum and Forsterygion varium). High-resolution respirometry coupled with fluorometric measurements of mitochondrial membrane potential (mtMP) permitted assessment of differences in mitochondrial function and integrity in response to intermittent hypoxia and anoxia. Traditional steady-state measures of respiratory flux and mtMP showed no differences among species. However, in the transition into anoxia, the tolerant species B. medius and F. lapillum maintained mtMP at O2 pressures 7- and 4.4-fold lower, respectively, than that of the hypoxia-sensitive F. varium and exhibited slower rates of membrane depolarisation. The results indicate that dynamic oxic-hypoxic mitochondria transitions underlie hypoxia tolerance in these intertidal fish.
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Affiliation(s)
- Alice R Harford
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Jules B L Devaux
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Anthony J R Hickey
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
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32
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Yue Y, Wang Y, Zhang B, Zeng J, Wang Q, Wang C, Peng S. Whole-Genome Methylation Sequencing of Large Yellow Croaker (Larimichthys crocea) Liver Under Hypoxia and Acidification Stress. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2023; 25:567-579. [PMID: 37450059 DOI: 10.1007/s10126-023-10226-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/08/2023] [Indexed: 07/18/2023]
Abstract
Large yellow croaker (Larimichthys crocea) is an important aquaculture species in China. This study analysed whole-genome methylation differences in liver tissues of young fish under different hypoxic and acidification conditions. Differentially methylated regions (DMRs) and differentially methylated genes (DMGs) were identified. Gene ontology (GO) and Kyoto encyclopaedia of genes and genomes (KEGG) enrichment analyses of DMGs were conducted to explore the mechanism of coping with hypoxic acidification. The main methylation type was CG, accounting for > 70% of total methylation, significantly higher than CHG and CHH methylation types. GO enrichment analysis of DMGs revealed strong enrichment of nervous system development, cell periphery, plasma membrane, cell junction organisation, cell junction, signalling receptor activity, molecular sensor activity, cell-linked tissue junction organisation, cell-cell adhesion and nervous system development. KEGG enrichment analysis of DMR-related genes identified cell adhesion molecules, cortisol synthesis and secretion and aldosterone synthesis and secretion as the three key pathways regulating the physiological responses to hypoxia and acidification. Long-term hypoxic and acidification stress affected the immune system, nervous system and stress responses of large yellow croaker. Whole-genome sequencing analysis of exposed tissues was used to investigate changes that occur in L. crocea in response to hypoxic and acidic conditions at the DNA methylation level. The findings contribute to our comprehensive understanding of functional methylation in large yellow croaker and will support future research on the response mechanisms of this species under different environmental pressures.
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Affiliation(s)
- Yanfeng Yue
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Yabing Wang
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Bianbian Zhang
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Jiao Zeng
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Qian Wang
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China
| | - Cuihua Wang
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China.
| | - Shiming Peng
- Key Laboratory of Marine and Estuarine Fisheries, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, People's Republic of China.
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33
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Li L, Shen S, Bickler P, Jacobson MP, Wu LF, Altschuler SJ. Searching for molecular hypoxia sensors among oxygen-dependent enzymes. eLife 2023; 12:e87705. [PMID: 37494095 PMCID: PMC10371230 DOI: 10.7554/elife.87705] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/09/2023] [Indexed: 07/27/2023] Open
Abstract
The ability to sense and respond to changes in cellular oxygen levels is critical for aerobic organisms and requires a molecular oxygen sensor. The prototypical sensor is the oxygen-dependent enzyme PHD: hypoxia inhibits its ability to hydroxylate the transcription factor HIF, causing HIF to accumulate and trigger the classic HIF-dependent hypoxia response. A small handful of other oxygen sensors are known, all of which are oxygen-dependent enzymes. However, hundreds of oxygen-dependent enzymes exist among aerobic organisms, raising the possibility that additional sensors remain to be discovered. This review summarizes known and potential hypoxia sensors among human O2-dependent enzymes and highlights their possible roles in hypoxia-related adaptation and diseases.
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Affiliation(s)
- Li Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San FranciscoSan FranciscoUnited States
| | - Susan Shen
- Department of Pharmaceutical Chemistry, University of California San Francisco, San FranciscoSan FranciscoUnited States
- Department of Psychiatry, University of California, San FranciscoSan FranciscoUnited States
| | - Philip Bickler
- Hypoxia Research Laboratory, University of California San Francisco, San FranciscoSan FranciscoUnited States
- Center for Health Equity in Surgery and Anesthesia, University of California San Francisco, San FranciscoSan FranciscoUnited States
- Anesthesia and Perioperative Care, University of California San Francisco, San FranciscoSan FranciscoUnited States
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, University of California San Francisco, San FranciscoSan FranciscoUnited States
| | - Lani F Wu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San FranciscoSan FranciscoUnited States
| | - Steven J Altschuler
- Department of Pharmaceutical Chemistry, University of California San Francisco, San FranciscoSan FranciscoUnited States
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Bundgaard A, Gruszczyk AV, Prag HA, Williams C, McIntyre A, Ruhr IM, James AM, Galli GLJ, Murphy MP, Fago A. Low production of mitochondrial reactive oxygen species after anoxia and reoxygenation in turtle hearts. J Exp Biol 2023; 226:jeb245516. [PMID: 37066839 PMCID: PMC10184768 DOI: 10.1242/jeb.245516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/03/2023] [Indexed: 04/18/2023]
Abstract
Extremely anoxia-tolerant animals, such as freshwater turtles, survive anoxia and reoxygenation without sustaining tissue damage to their hearts. In contrast, for mammals, the ischemia-reperfusion (IR) injury that leads to tissue damage during a heart attack is initiated by a burst of superoxide (O2·-) production from the mitochondrial respiratory chain upon reperfusion of ischemic tissue. Whether turtles avoid oxidative tissue damage because of an absence of mitochondrial superoxide production upon reoxygenation, or because the turtle heart is particularly protected against this damage, is unclear. Here, we investigated whether there was an increase in mitochondrial O2·- production upon the reoxygenation of anoxic red-eared slider turtle hearts in vivo and in vitro. This was done by measuring the production of H2O2, the dismutation product of O2·-, using the mitochondria-targeted mass-spectrometric probe in vivo MitoB, while in parallel assessing changes in the metabolites driving mitochondrial O2·- production, succinate, ATP and ADP levels during anoxia, and H2O2 consumption and production rates of isolated heart mitochondria. We found that there was no excess production of in vivo H2O2 during 1 h of reoxygenation in turtles after 3 h anoxia at room temperature, suggesting that turtle hearts most likely do not suffer oxidative injury after anoxia because their mitochondria produce no excess O2·- upon reoxygenation. Instead, our data support the conclusion that both the low levels of succinate accumulation and the maintenance of ADP levels in the anoxic turtle heart are key factors in preventing the surge of O2·- production upon reoxygenation.
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Affiliation(s)
- Amanda Bundgaard
- CECAD, University of Cologne, 50931 Cologne, Germany
- Department of Biology, Aarhus University, DK-8000 Aarhus, Denmark
| | - Anja V. Gruszczyk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Hiran A. Prag
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | | | - Angela McIntyre
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Ilan M. Ruhr
- Faculty of Medical and Human Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Andrew M. James
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Gina L. J. Galli
- Faculty of Medical and Human Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Michael P. Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Angela Fago
- Department of Biology, Aarhus University, DK-8000 Aarhus, Denmark
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Zhao SS, Su XL, Yang HQ, Zheng GD, Zou SM. Functional exploration of SNP mutations in HIF2αb gene correlated with hypoxia tolerance in blunt snout bream (Megalobrama amblycephala). FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:239-251. [PMID: 36859574 DOI: 10.1007/s10695-023-01173-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 02/13/2023] [Indexed: 05/04/2023]
Abstract
Blunt snout bream (Megalobrama amblycephala) is sensitive to hypoxia environment. Hypoxia-inducible factor (HIF) is the most critical factor in the HIF pathway, which strictly regulates the hypoxia stress process of fish. In this study, we found six hifα genes in blunt snout bream that demonstrated different expressions under hypoxia conditions. In HEK293T cells, all six hifαs were detected to activate the HRE region by luciferase reporter assay. More importantly, we identified two linkage-disequilibrium SNP sites at exon 203 and 752 of the hif2αb gene in blunt snout bream. Haplotype II (A203A752) and its homozygous diplotype II (A203A203A752A752) appeared frequently in a selected strain of blunt snout bream with hypoxia tolerance. Diplotype II has a lower oxygen tension threshold for loss of equilibrium (LOEcrit) over a similar range of temperatures. Moreover, its erythrocyte number increased significantly (p < 0.05) than those in diplotype I and diplotype III strains at 48 h of hypoxia. The enzymes related with hypoxia tolerant traits, i.e., reduced glutathione, superoxide dismutase, and catalase, were also significantly (p < 0.05) induced in diplotype II than in diplotype I or III. In addition, the expression of epo in the liver of diplotype II was significantly (p < 0.01) higher than that in the diplotype I or III strains at 48 h of hypoxia. Taken together, our results found that the hypoxia-tolerant-related diplotype II of hif2αb has the potential to be used as a molecular marker in future genetic breeding of hypoxia-tolerant strain.
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Affiliation(s)
- Shan-Shan Zhao
- National Demonstration Center for Experimental Fisheries Science Education, Genetics and Breeding Center for Blunt Snout Bream, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
- Zhejiang Ocean University, Zhejiang, 316022, China
| | - Xiao-Lei Su
- National Demonstration Center for Experimental Fisheries Science Education, Genetics and Breeding Center for Blunt Snout Bream, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Hui-Qi Yang
- National Demonstration Center for Experimental Fisheries Science Education, Genetics and Breeding Center for Blunt Snout Bream, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Guo-Dong Zheng
- National Demonstration Center for Experimental Fisheries Science Education, Genetics and Breeding Center for Blunt Snout Bream, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China.
| | - Shu-Ming Zou
- National Demonstration Center for Experimental Fisheries Science Education, Genetics and Breeding Center for Blunt Snout Bream, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China.
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36
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Jiang T, Liang YS, Gu Y, Yao FC, Liu YF, Zhang KX, Song FB, Sun JL, Luo J. Different reoxygenation rates induce different metabolic, apoptotic and immune responses in Golden Pompano (Trachinotus blochii) after hypoxic stress. FISH & SHELLFISH IMMUNOLOGY 2023; 135:108640. [PMID: 36871632 DOI: 10.1016/j.fsi.2023.108640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/11/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Dissolved oxygen (DO) is essential for teleosts, and fluctuating environmental factors can result in hypoxic stress in the golden pompano (Trachinotus blochii). However, it is unknown whether different recovery speeds of DO concentration after hypoxia induce stress in T. blochii. In this study, T. blochii was subjected to hypoxic conditions (1.9 ± 0.2 mg/L) for 12 h followed by 12 h of reoxygenation at two different speeds (30 mg/L per hour and 1.7 mg/L per hour increasing). The gradual reoxygenation group (GRG), experienced DO recovery (1.9 ± 0.2 to 6.8 ± 0.2 mg/L) within 3 h, and the rapid reoxygenation group (RRG), experienced DO recovery (1.9 ± 0.2 to 6.8 ± 0.2 mg/L) within 10 min. Physiological and biochemical parameters of metabolism (glucose, glycegon, lactic acid (LD), lactate dehydrogenase (LDH), pyruvic acid (PA), phosphofructokinase (PFKA), and hexokinase (HK), triglyceride (TG), lipoprotein lipase (LPL), carnitine palmitoyltransferase 1 (CPT-1)) and transcriptome sequencing (RNA-seq of liver) were monitored to identify the effects of the two reoxygenation speeds. Increased LD content and increased activity of LDH, PA, PFKA, and HK suggested enhanced anaerobic glycolysis under hypoxic stress. LD and LDH levels remained significantly elevated during reoxygenation, indicating that the effects of hypoxia were not immediately alleviated during reoxygenation. The expressions of PGM2, PFKA, GAPDH, and PK were increased in the RRG, which suggests that glycolysis was enhanced. The same pattern was not observed in the GRG. Additionally, In the RRG, reoxygenation may promote glycolysis to guarantee energy supply. However, the GRG may through the lipid metabolism such as steroid biosynthesis at the later stage of reoxygenation. In the aspect of apoptosis, differentially expressed genes (DEGs) in the RRG were enriched in the p53 signaling pathway, which promoted cell apoptosis, while DEGs in the GRG seem to activate cell apoptosis at early stage of reoxygenation but was restrained latterly. DEGs in both the RRG and the GRG were enriched in the NF-kappa B and JAK-STAT signaling pathways, the RRG may induce cell survival by regulating the expression of IL-12B, COX2, and Bcl-XL, while in the GRG it may induce by regulating the expression of IL-8. Moreover, DEGs in the RRG were also enriched in the Toll-like receptor signaling pathway. This research revealed that at different velocity of reoxygenation after hypoxic stress, T. blochii would represent different metabolic, apoptotic and immune strategies, and this conclusion would provide new insight into the response to hypoxia and reoxygenation in teleosts.
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Affiliation(s)
- Tian Jiang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Ye Song Liang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Yue Gu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Fu Cheng Yao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Yi Fan Liu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Kai Xi Zhang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Fei Biao Song
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Jun Long Sun
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
| | - Jian Luo
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Aquaculture Breeding Engineering Research Center, Hainan Academician Team Innovation Center, Hainan University, Haikou, 570228, China.
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37
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Amaral-Silva L, Santin JM. Synaptic modifications transform neural networks to function without oxygen. BMC Biol 2023; 21:54. [PMID: 36927477 PMCID: PMC10022038 DOI: 10.1186/s12915-023-01518-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/18/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND Neural circuit function is highly sensitive to energetic limitations. Much like mammals, brain activity in American bullfrogs quickly fails in hypoxia. However, after emergence from overwintering, circuits transform to function for approximately 30-fold longer without oxygen using only anaerobic glycolysis for fuel, a unique trait among vertebrates considering the high cost of network activity. Here, we assessed neuronal functions that normally limit network output and identified components that undergo energetic plasticity to increase robustness in hypoxia. RESULTS In control animals, oxygen deprivation depressed excitatory synaptic drive within native circuits, which decreased postsynaptic firing to cause network failure within minutes. Assessments of evoked and spontaneous synaptic transmission showed that hypoxia impairs synaptic communication at pre- and postsynaptic loci. However, control neurons maintained membrane potentials and a capacity for firing during hypoxia, indicating that those processes do not limit network activity. After overwintering, synaptic transmission persisted in hypoxia to sustain motor function for at least 2 h. CONCLUSIONS Alterations that allow anaerobic metabolism to fuel synapses are critical for transforming a circuit to function without oxygen. Data from many vertebrate species indicate that anaerobic glycolysis cannot fuel active synapses due to the low ATP yield of this pathway. Thus, our results point to a unique strategy whereby synapses switch from oxidative to exclusively anaerobic glycolytic metabolism to preserve circuit function during prolonged energy limitations.
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Affiliation(s)
- Lara Amaral-Silva
- Division of Biological Sciences, The University of Missouri, Columbia, USA.
| | - Joseph M Santin
- Division of Biological Sciences, The University of Missouri, Columbia, USA.
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38
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Zeng LF, Lee J, Lim G, Yang YF, Lin RL, Yin SJ, Wang W, Park YD. Characterization and tissue expression analysis of mitochondrial creatine kinases (types I and II) from Pelodiscus sinensis. J Biomol Struct Dyn 2023; 41:1388-1402. [PMID: 34939522 DOI: 10.1080/07391102.2021.2020168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The aim of this study was to characterize the functions of the mitochondrial creatine kinases in the Chinese soft-shelled turtle Pelodiscus sinensis (PSCK-MT1 and PSCK-MT2) to characterize function in relation to hibernation. Computational prediction via molecular dynamics simulations showed that PSCK-MT1 had stronger kinase- and creatine-binding affinity than PSCK-MT2. We measured PSCK-MT1 and PSCK-MT2 levels in the myocardium, liver, spleen, lung, kidney, and ovary of P. sinensis before and after hibernation and found that the expression of these enzymes was the most significantly upregulated in the ovary. We enumerated the ovarian follicles and evaluated the physiological indices of P. sinensis and discovered that fat was the main form of energy storage in P. sinensis. Moreover, both PSCK-MTs promoted follicular development during hibernation. Immunohistochemistry was used to study follicular development and revealed that both PSCK-MTs were expressed primarily in the follicular fluid and granulosa layer before and after hibernation. We found that PSCK-MT1 and PSCK-MT2 could play important roles in ovarian follicular development under hibernation. Hence, both PSCK-MTs probably function effectively under the conditions of low temperature and oxygen during hibernation. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Li-Fang Zeng
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, PR China
| | - Jinhyuk Lee
- Genome Editing Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.,Department of Bioinformatics, KRIBB School of Bioscience, University of Science and Technology (UST), Daejeon, Korea
| | - Gyutae Lim
- Genome Editing Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.,Department of Bioinformatics, KRIBB School of Bioscience, University of Science and Technology (UST), Daejeon, Korea
| | - Yu-Fei Yang
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, PR China
| | - Run-Lan Lin
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, PR China
| | - Shang-Jun Yin
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, PR China
| | - Wei Wang
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, PR China
| | - Yong-Doo Park
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, PR China.,Skin Diseases Research Center, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, PR China.,Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, PR China
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39
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Enlarged fins of Tibetan catfish provide new evidence of adaptation to high plateau. SCIENCE CHINA. LIFE SCIENCES 2023:10.1007/s11427-022-2253-7. [PMID: 36802318 DOI: 10.1007/s11427-022-2253-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/30/2022] [Indexed: 02/23/2023]
Abstract
The uplift of the Tibetan Plateau significantly altered the geomorphology and climate of the Euroasia by creating large mountains and rivers. Fishes are more likely to be affected relative to other organisms, as they are largely restricted to river systems. Faced with the rapidly flowing water in the Tibetan Plateau, a group of catfish has evolved greatly enlarged pectoral fins with more numbers of fin-rays to form an adhesive apparatus. However, the genetic basis of these adaptations in Tibetan catfishes remains elusive. In this study, we performed comparative genomic analyses based on the chromosome-level genome of Glyptosternum maculatum in family Sisoridae and detected some proteins with conspicuously high evolutionary rates in particular in genes involved in skeleton development, energy metabolism, and hypoxia response. We found that the hoxd12a gene evolved faster and a loss-of-function assay of hoxd12a supports a potential role for this gene in shaping the enlarged fins of these Tibetan catfishes. Other genes with amino acid replacements and signatures of positive selection included proteins involved in low temperature (TRMU) and hypoxia (VHL) responses. Functional assays reveal that the G. maculatumTRMU allele generates more mitochondrial ATP than the ancestral allele found in low-altitude fishes. Functional assays of VHL alleles suggest that the G. maculatum allele has lower transactivation activity than the low-altitude forms. These findings provide a window into the genomic underpinnings of physiological adaptations that permit G. maculatum to survive in the harsh environment of the Tibetan Himalayas that mirror those that are convergently found in other vertebrates such as humans.
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40
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Molina JM, Kunzmann A, Reis JP, Guerreiro PM. Metabolic Responses and Resilience to Environmental Challenges in the Sedentary Batrachoid Halobatrachus didactylus (Bloch & Schneider, 1801). Animals (Basel) 2023; 13:ani13040632. [PMID: 36830420 PMCID: PMC9951689 DOI: 10.3390/ani13040632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/06/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
In the context of climate change, warming of the seas and expansion of hypoxic zones are challenges that most species of fish are, or will be subjected to. Understanding how different species cope with these changes in their environment at the individual level can shed light on how populations and ecosystems will be affected. We provide first-time estimates on the metabolic rates, thermal, and oxygen-related limits for Halobatrachus didactylus, a coastal sedentary fish that lives in intertidal environments of the Northeast Atlantic. Using respirometry in different experimental designs, we found that this species is highly resistant to acute thermal stress (CTmax: 34.82 ± 0.66 °C) and acute hypoxia (Pcrit: 0.59-1.97 mg O2 L-1). We found size-specific differences in this stress response, with smaller individuals being more sensitive. We also quantified its aerobic scope and daily activity patterns, finding this fish to be extremely sedentary, with one of the lowest standard metabolic rates found in temperate fish (SMR: 14.96 mg O2 kg-1h-1). H. didactylus activity increases at night, when its metabolic rate increases drastically (RMR: 36.01 mg O2 kg-1h-1). The maximum metabolic rate of H. didactylus was estimated to be 67.31 mg O2 kg-1h-1, producing an aerobic scope of 52.35 mg O2 kg-1h-1 (77.8% increase). The metrics obtained in this study prove that H. didactylus is remarkably resilient to acute environmental variations in temperature and oxygen content, which might enable it to adapt to the extreme abiotic conditions forecasted for the world's oceans in the near future.
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Affiliation(s)
- Juan Manuel Molina
- Instituto Argentino de Oceanografía (CONICET), Bahía Blanca B8000, Argentina
- Leibniz-Zentrum für Marine Tropenforschung (ZMT), 28359 Bremen, Germany
- Centro de Ciências do Mar (CCMAR), Universidade do Algarve, 8005-139 Faro, Portugal
- Correspondence:
| | - Andreas Kunzmann
- Leibniz-Zentrum für Marine Tropenforschung (ZMT), 28359 Bremen, Germany
| | - João Pena Reis
- Centro de Ciências do Mar (CCMAR), Universidade do Algarve, 8005-139 Faro, Portugal
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41
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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] [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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42
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Cerra MC, Filice M, Caferro A, Mazza R, Gattuso A, Imbrogno S. Cardiac Hypoxia Tolerance in Fish: From Functional Responses to Cell Signals. Int J Mol Sci 2023; 24:ijms24021460. [PMID: 36674975 PMCID: PMC9866870 DOI: 10.3390/ijms24021460] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/14/2023] Open
Abstract
Aquatic animals are increasingly challenged by O2 fluctuations as a result of global warming, as well as eutrophication processes. Teleost fish show important species-specific adaptability to O2 deprivation, moving from intolerance to a full tolerance of hypoxia and even anoxia. An example is provided by members of Cyprinidae which includes species that are amongst the most tolerant hypoxia/anoxia teleosts. Living at low water O2 requires the mandatory preservation of the cardiac function to support the metabolic and hemodynamic requirements of organ and tissues which sustain whole organism performance. A number of orchestrated events, from metabolism to behavior, converge to shape the heart response to the restricted availability of the gas, also limiting the potential damages for cells and tissues. In cyprinids, the heart is extraordinarily able to activate peculiar strategies of functional preservation. Accordingly, by using these teleosts as models of tolerance to low O2, we will synthesize and discuss literature data to describe the functional changes, and the major molecular events that allow the heart of these fish to sustain adaptability to O2 deprivation. By crossing the boundaries of basic research and environmental physiology, this information may be of interest also in a translational perspective, and in the context of conservative physiology, in which the output of the research is applicable to environmental management and decision making.
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43
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Taboada C, Delia J, Chen M, Ma C, Peng X, Zhu X, Jiang L, Vu T, Zhou Q, Yao J, O’Connell L, Johnsen S. Glassfrogs conceal blood in their liver to maintain transparency. Science 2022; 378:1315-1320. [PMID: 36548427 PMCID: PMC9984244 DOI: 10.1126/science.abl6620] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cells (RBCs) that strongly attenuate light. Here, we document how glassfrogs overcome this challenge by concealing these cells from view. Using photoacoustic imaging to track RBCs in vivo, we show that resting glassfrogs increase transparency two- to threefold by removing ~89% of their RBCs from circulation and packing them within their liver. Vertebrate transparency thus requires both see-through tissues and active mechanisms that "clear" respiratory pigments from these tissues. Furthermore, glassfrogs' ability to regulate the location, density, and packing of RBCs without clotting offers insight in metabolic, hemodynamic, and blood-clot research.
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Affiliation(s)
- Carlos Taboada
- Biology Department, Duke University, Durham, NC, USA,Department of Biomedical Engineering, Duke University, Durham, NC, USA,Corresponding author.(C.T.);(J.D.);(J.Y.)
| | - Jesse Delia
- Department of Biomedical Engineering, Duke University, Durham, NC, USA,Department of Biology, Stanford University, Stanford, CA, USA,Division of Vertebrate Zoology and Richard Gilder Graduate School, American Museum of Natural History, New York, NY, USA,Corresponding author.(C.T.);(J.D.);(J.Y.)
| | - Maomao Chen
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Chenshuo Ma
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Xiaorui Peng
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Xiaoyi Zhu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Laiming Jiang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Tri Vu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA,Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA,USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC, USA,Corresponding author.(C.T.);(J.D.);(J.Y.)
| | | | - Sönke Johnsen
- Biology Department, Duke University, Durham, NC, USA
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Ding K, Barretto EC, Johnston M, Lee B, Gallo M, Grewal SS. Transcriptome analysis of FOXO-dependent hypoxia gene expression identifies Hipk as a regulator of low oxygen tolerance in Drosophila. G3 (BETHESDA, MD.) 2022; 12:6749561. [PMID: 36200850 PMCID: PMC9713431 DOI: 10.1093/g3journal/jkac263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/16/2022] [Indexed: 12/05/2022]
Abstract
When exposed to low oxygen or hypoxia, animals must alter their metabolism and physiology to ensure proper cell-, tissue-, and whole-body level adaptations to their hypoxic environment. These alterations often involve changes in gene expression. While extensive work has emphasized the importance of the HIF-1 alpha transcription factor on controlling hypoxia gene expression, less is known about other transcriptional mechanisms. We previously identified the transcription factor FOXO as a regulator of hypoxia tolerance in Drosophila larvae and adults. Here, we use an RNA-sequencing approach to identify FOXO-dependent changes in gene expression that are associated with these tolerance effects. We found that hypoxia altered the expression of over 2,000 genes and that ∼40% of these gene expression changes required FOXO. We discovered that hypoxia exposure led to a FOXO-dependent increase in genes involved in cell signaling, such as kinases, GTPase regulators, and regulators of the Hippo/Yorkie pathway. Among these, we identified homeodomain-interacting protein kinase as being required for hypoxia survival. We also found that hypoxia suppresses the expression of genes involved in ribosome synthesis and egg production, and we showed that hypoxia suppresses tRNA synthesis and mRNA translation and reduces female fecundity. Among the downregulated genes, we discovered that FOXO was required for the suppression of many ribosomal protein genes and genes involved in oxidative phosphorylation, pointing to a role for FOXO in limiting energetically costly processes such as protein synthesis and mitochondrial activity upon hypoxic stress. This work uncovers a widespread role for FOXO in mediating hypoxia changes in gene expression.
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Affiliation(s)
- Kate Ding
- Clark H. Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.,Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Elizabeth C Barretto
- Clark H. Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.,Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Michael Johnston
- Clark H. Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.,Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Byoungchun Lee
- Clark H. Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.,Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Marco Gallo
- Clark H. Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.,Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Savraj S Grewal
- Clark H. Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.,Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, AB T2N 4N1, Canada
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45
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Zhu W, Zhao C, Zhao T, Chang L, Chen Q, Liu J, Li C, Xie F, Jiang J. Rising floor and dropping ceiling: organ heterogeneity in response to cold acclimation of the largest extant amphibian. Proc Biol Sci 2022; 289:20221394. [PMID: 36196548 PMCID: PMC9532983 DOI: 10.1098/rspb.2022.1394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/09/2022] [Indexed: 02/06/2023] Open
Abstract
Low temperature imposes strong selective pressure on ectotherms. To maximize their overall fitness under cold conditions, the ectotherms may either try to maintain their physiological activities through metabolic compensation or enter into metabolic depression; however, some species adopt both strategies to cope with different degrees of cold. Nevertheless, how these two seemingly opposite strategies are coordinated has rarely been elucidated. Here, we investigated the molecular strategy underlying the cold acclimation of Andrias davidianus, the largest extant amphibian, using multi-organ metabolomics and transcriptomics. The results showed remarkable organ heterogeneity in response to cold. While most organs showed transcriptional upregulation of metabolic processes, the heart exhibited downregulation. This heterogeneity explained the adaptive reorganization in resource allocation, which compensates for metabolic maintenance by compromising growth. Importantly, the cardiac function might constitute a 'ceiling' to constrain the space for compensation, especially under colder conditions. Additionally, the opposite transcriptional regulation of oxidative phosphorylation and other pathways might also shape the overall metabolic capacity under cold conditions. The heterogeneity in cold responses may have directed a shift in cold adaptive strategy from compensation to depression with a drop in temperature. These results provide a novel insight into the regulatory mechanisms underlying cold survival strategies of ectotherms.
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Affiliation(s)
- Wei Zhu
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Chunlin Zhao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
| | - Tian Zhao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
| | - Liming Chang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Qiheng Chen
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jiongyu Liu
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
| | - Cheng Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
| | - Feng Xie
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
| | - Jianping Jiang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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Zaccone G, Capillo G, Aragona M, Alesci A, Cupello C, Lauriano ER, Guerrera MC, Kuciel M, Zuwala K, Germana A, Icardo JM. Gill structure and neurochemical markers in the African bonytongue (Heterotis niloticus): A preliminary study. Acta Histochem 2022; 124:151954. [PMID: 36174310 DOI: 10.1016/j.acthis.2022.151954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 11/01/2022]
Abstract
We have conducted a morphological and immunohistochemical study of the gills of juvenile specimens of the obligate air-breathing fish Heterotis niloticus. The study has been performed under normoxic and hypoxic conditions. The gills showed a reduced respiratory surface area by development of an interlamellar cellular mass (ILCM). The ILCM persisted without changes under both normoxia and hypoxia. Neuroepithelial cells (NECs), the major oxygen and hypoxia sensing cell type, were located in the distal end of the gill filaments and along the ILCM edges. These cells expressed 5HT, the neuronal isoform of the nitric oxide synthase (nNOS) and the vesicular acetylcholine transporter (VAChT). Furthermore, NECs appeared associated with nitrergic nerve fibres. The O2 levels did not modify the location, number or the immunohistochemical characteristics of NECs. Pavement cells covering the ILCM were also positive to nNOS and VAChT. The mechanisms of O2 sensing in the gills of Heterotis appears to involve several cell populations, the release of multiple neurotransmitters and a diversity of excitatory, inhibitory and modulatory mechanisms.
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Affiliation(s)
- Giacomo Zaccone
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Gioele Capillo
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy; Institute for Marine Biological Resources and Biotechnology (IRBIM), National Research Council (CNR), 98122 Messina, Italy.
| | - Marialuisa Aragona
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Alessio Alesci
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy
| | - Camila Cupello
- Departamento de Zoologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, 20550-900, Rio de Janeiro, Brazil.
| | - Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy.
| | - Maria Cristina Guerrera
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Michal Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagellonian University, Kopernika 15, 30-501 Krakòw, Poland.
| | - Kristina Zuwala
- Department of Comparative Anatomy, Institute of Zoology and Biomedical Researches, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland.
| | - Antonino Germana
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Josè Manuel Icardo
- Department of Anatomy and Cell Biology, Poligono de Cazoña, Faculty of Medicine, University of Cantabria, Santander, Spain.
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Zhao L, Yan H, Cheng L, He K, Liu Q, Luo J, Luo W, Zhang X, Yan T, Du Z, Li Z, Yang S. Metabolic response provides insights into the mechanism of adaption to hypoxia in largemouth bass (Micropterus salmoides) under intermittent hypoxic conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 242:113957. [PMID: 35999769 DOI: 10.1016/j.ecoenv.2022.113957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
In metabolism, molecular oxygen is a necessary substrate. Oxygen imbalances are linked to a variety of circumstances in the organism's homeostasis. Recently, the positive effects of hypoxia treatment in improving exercise ability and hypoxia tolerance have become a research focus. We explored the effects of intermittent hypoxia exposure (IHE, for one hour or three hours per day) on the hypoxia tolerance of largemouth bass in this study. The results showed that (1) IHE significantly reduced the LOEcrit (the critical O2 tension for loss of equilibrium) value of largemouth bass, indicating that its hypoxia tolerance was enhanced. (2) The level of oxidative stress in the liver decreased in the HH3 group (exposed to a hypoxic condition for 3 h per day) compared to HH1 group (exposed to a hypoxic condition for 1 h per day). (3) IHE reduced the content of lactic acid and enhanced the process of gluconeogenesis in the liver. (4) Importantly, lipid mobilization and fatty acid oxidation in the liver of largemouth bass were significantly enhanced during IHE. In short, the results of this study indicate that IHE can improve hypoxia tolerance by regulating the energy metabolism of largemouth bass.
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Affiliation(s)
- Liulan Zhao
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Haoxiao Yan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Liangshun Cheng
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Kuo He
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Qiao Liu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Jie Luo
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Wei Luo
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Xin Zhang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Taiming Yan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Zongjun Du
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Zhiqiong Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Song Yang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
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48
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Hu R, Li G, Xu Q, Chen L. Iron supplementation inhibits hypoxia-induced mitochondrial damage and protects zebrafish liver cells from death. Front Physiol 2022; 13:925752. [PMID: 36091397 PMCID: PMC9459849 DOI: 10.3389/fphys.2022.925752] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/27/2022] [Indexed: 11/15/2022] Open
Abstract
Acute hypoxia in water has always been a thorny problem in aquaculture. Oxygen and iron play important roles and are interdependent in fish. Iron is essential for oxygen transport and its concentration tightly controlled to maintain the cellular redox homeostasis. However, it is still unclear the role and mechanism of iron in hypoxic stress of fish. In this study, we investigated the role of iron in hypoxic responses of two zebrafish-derived cell lines. We found hypoxia exposed zebrafish liver cells (ZFL) demonstrated reduced expression of Ferritin and the gene fth31 for mitochondrial iron storage, corresponding to reduction of both intracellular and mitochondrial free iron and significant decrease of ROS levels in multiple cellular components, including mitochondrial ROS and lipid peroxidation level. In parallel, the mitochondrial integrity was severely damaged. Addition of exogenous iron restored the iron and ROS levels in cellular and mitochondria, reduced mitochondrial damage through enhancing mitophagy leading to higher cell viability, while treated the cells with iron chelator (DFO) or ferroptosis inhibitor (Fer-1) showed no improvements of the cellular conditions. In contrast, in hypoxia insensitive zebrafish embryonic fibroblasts cells (ZF4), the expression of genes related to iron metabolism showed opposite trends of change and higher mitochondrial ROS level compared with the ZFL cells. These results suggest that iron homeostasis is important for zebrafish cells to maintain mitochondrial integrity in hypoxic stress, which is cell type dependent. Our study enriched the hypoxia regulation mechanism of fish, which helped to reduce the hypoxia loss in fish farming.
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Affiliation(s)
- Ruiqin Hu
- International Joint Research Centre for Marine Biosciences (Ministry of Science and Technology), College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Ministry of Education) and International Research Centre for Marine Biosciences, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Genfang Li
- International Joint Research Centre for Marine Biosciences (Ministry of Science and Technology), College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Ministry of Education) and International Research Centre for Marine Biosciences, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Qianghua Xu
- International Joint Research Centre for Marine Biosciences (Ministry of Science and Technology), College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Ministry of Education) and International Research Centre for Marine Biosciences, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, College of Marine Science, Shanghai Ocean University, Shanghai, China
| | - Liangbiao Chen
- International Joint Research Centre for Marine Biosciences (Ministry of Science and Technology), College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Ministry of Education) and International Research Centre for Marine Biosciences, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- *Correspondence: Liangbiao Chen,
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Hussan MT, Sakai A, Matsui H. Glutamatergic pathways in the brains of turtles: A comparative perspective among reptiles, birds, and mammals. Front Neuroanat 2022; 16:937504. [PMID: 36059432 PMCID: PMC9428285 DOI: 10.3389/fnana.2022.937504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
Glutamate acts as the main excitatory neurotransmitter in the brain and plays a vital role in physiological and pathological neuronal functions. In mammals, glutamate can cause detrimental excitotoxic effects under anoxic conditions. In contrast, Trachemys scripta, a freshwater turtle, is one of the most anoxia-tolerant animals, being able to survive up to months without oxygen. Therefore, turtles have been investigated to assess the molecular mechanisms of neuroprotective strategies used by them in anoxic conditions, such as maintaining low levels of glutamate, increasing adenosine and GABA, upregulating heat shock proteins, and downregulating KATP channels. These mechanisms of anoxia tolerance of the turtle brain may be applied to finding therapeutics for human glutamatergic neurological disorders such as brain injury or cerebral stroke due to ischemia. Despite the importance of glutamate as a neurotransmitter and of the turtle as an ideal research model, the glutamatergic circuits in the turtle brain remain less described whereas they have been well studied in mammalian and avian brains. In reptiles, particularly in the turtle brain, glutamatergic neurons have been identified by examining the expression of vesicular glutamate transporters (VGLUTs). In certain areas of the brain, some ionotropic glutamate receptors (GluRs) have been immunohistochemically studied, implying that there are glutamatergic target areas. Based on the expression patterns of these glutamate-related molecules and fiber connection data of the turtle brain that is available in the literature, many candidate glutamatergic circuits could be clarified, such as the olfactory circuit, hippocampal–septal pathway, corticostriatal pathway, visual pathway, auditory pathway, and granule cell–Purkinje cell pathway. This review summarizes the probable glutamatergic pathways and the distribution of glutamatergic neurons in the pallium of the turtle brain and compares them with those of avian and mammalian brains. The integrated knowledge of glutamatergic pathways serves as the fundamental basis for further functional studies in the turtle brain, which would provide insights on physiological and pathological mechanisms of glutamate regulation as well as neural circuits in different species.
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Affiliation(s)
- Mohammad Tufazzal Hussan
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
- Department of Anatomy and Histology, Patuakhali Science and Technology University, Barishal, Bangladesh
- *Correspondence: Mohammad Tufazzal Hussan,
| | - Akiko Sakai
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
| | - Hideaki Matsui
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan
- Hideaki Matsui,
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50
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Country MW, Jonz MG. Goldfish and crucian carp are natural models of anoxia tolerance in the retina. Comp Biochem Physiol A Mol Integr Physiol 2022; 270:111244. [PMID: 35618216 DOI: 10.1016/j.cbpa.2022.111244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 10/18/2022]
Abstract
Vertebrates need oxygen to survive. The central nervous system has an especially high energy demand, so brain and retinal neurons quickly die in anoxia. But fish of the genus Carassius are exceptionally anoxia-tolerant: the crucian carp (C. carassius) can survive months without oxygen in ice-covered ponds, and the common goldfish (C. auratus) can withstand hours of anoxia at room temperature. These fish previously offered insights into anoxia tolerance in the brain, heart, and liver. Here, we advance Carassius spp. as models to study anoxia tolerance in the retina. Electroretinogram and evoked potential recordings show that crucian carp reversibly downregulate their visual systems in anoxia, probably to save ATP. Notably, Carassius suppress their visual systems nearly twice as much as anoxia-tolerant turtles, Trachemys and Chrysemys spp., which are often promoted as the champions of anoxia tolerance. We summarize what is known about anoxia tolerance in the goldfish and crucian carp retinas, including cellular pathways which may protect retinal neurons from excitotoxic cell death. We compare the Carassius retina with two relevant models: natural anoxia tolerance in the turtle brain, and ischemic preconditioning in the rat retina. All three models include mitochondria as oxygen sensors: mitochondria depolarize due to mitochondrial ATP-dependent K+ channels, possibly to trigger neuroprotective second messenger cascades. The Carassius retina is an accessible and inexpensive model, with over 70 fruitful years of history in vision research. As a model for anoxia tolerance, it may provide new insights into diseases of the eye (like diabetes, macular degeneration, and eye stroke).
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Affiliation(s)
- Michael W Country
- Department of Biology, University of Ottawa, Canada. https://twitter.com/biologycountry
| | - Michael G Jonz
- Department of Biology, University of Ottawa, Canada; Brain and Mind Research Institute, University of Ottawa, Canada.
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