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Shaftoe JB, Manchester EA, Gillis TE. Cardiac remodeling caused by cold acclimation is reversible with rewarming in zebrafish (Danio rerio). Comp Biochem Physiol A Mol Integr Physiol 2023; 283:111466. [PMID: 37302568 DOI: 10.1016/j.cbpa.2023.111466] [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: 04/08/2023] [Revised: 05/31/2023] [Accepted: 06/08/2023] [Indexed: 06/13/2023]
Abstract
Cold acclimation of zebrafish causes changes to the structure and composition of the heart. However, little is known of the consequences of these changes on heart function or if these changes are reversible with rewarming back to the initial temperature. In the current study, zebrafish were acclimated from 27℃ to 20°C, then after 17 weeks, a subset of fish were rewarmed to 27°C and held at that temperature for 7 weeks. The length of this trial, 23 weeks, was chosen to mimic seasonal changes in temperature. Cardiac function was measured in each group at 27°C and 20°C using high frequency ultrasound. It was found that cold acclimation caused a decrease in ventricular cross-sectional area, compact myocardial thickness, and total muscle area. There was also a decrease in end-diastolic area with cold acclimation that reversed upon rewarming to control temperatures. Rewarming caused an increase in the thickness of the compact myocardium, total muscle area, and end-diastolic area back to control levels. This is the first experiment to demonstrate that cardiac remodeling, induced by cold acclimation, is reversible upon re-acclimation to control temperature (27°C). Finally, body condition measurements reveal that fish that had been cold-acclimated and then reacclimated to 27°C, were in poorer condition than the fish that remained at 20°C as well as the control fish at week 23. This suggests that the physiological responses to the multiple changes in temperature had a significant energetic cost to the animal. SUMMARY STATEMENT: The decrease in cardiac muscle density, compact myocardium thickness and diastolic area in zebrafish caused by cold acclimation, was reversed with rewarming to control temperatures.
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Affiliation(s)
- Jared B Shaftoe
- Department of Integrative Biology, University of Guelph, Canada
| | | | - Todd E Gillis
- Department of Integrative Biology, University of Guelph, Canada.
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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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [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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