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Oda GA, Valentinuzzi VS. A clock for all seasons in the subterranean. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:677-689. [PMID: 37815602 DOI: 10.1007/s00359-023-01677-z] [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: 03/30/2023] [Revised: 09/14/2023] [Accepted: 10/02/2023] [Indexed: 10/11/2023]
Abstract
In 1976, Pittendrigh and Daan established a theoretical framework which has coordinated research on circadian clock entrainment and photoperiodism until today. The "wild clocks" approach, which concerns studying wild species in their natural habitats, has served to test their models, add new insights, and open new directions of research. Here, we review an integrated laboratory, field and modeling work conducted with subterranean rodents (Ctenomys sp.) living under an extreme pattern of natural daily light exposure. Tracking animal movement and light exposure with biologgers across seasons and performing laboratory experiments on running-wheel cages, we uncovered the mechanisms of day/night entrainment of the clock and of photoperiodic time measurement in this subterranean organism. We confirmed most of the features of Pittendrigh and Daan's models but highlighted the importance of integrating them with ecophysiological techniques, methodologies, and theories to get a full picture of the clock in the wild. This integration is essential to fully establish the importance of the temporal dimension in ecological studies and tackling relevant questions such as the role of the clock for all seasons in a changing planet.
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Affiliation(s)
- Gisele A Oda
- Laboratório Binacional de Cronobiologia, Universidade de São Paulo, São Paulo, SP, Brazil.
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Yue F, Xia K, Wei L, Xing L, Wu S, Shi Y, Lam SM, Shui G, Xiang X, Russell R, Zhang D. Effects of constant light exposure on sphingolipidomics and progression of NASH in high-fat-fed rats. J Gastroenterol Hepatol 2020; 35:1978-1989. [PMID: 32027419 DOI: 10.1111/jgh.15005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/25/2020] [Accepted: 02/02/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIM Non-alcoholic fatty liver disease (NAFLD) is a growing public health concern worldwide. With the progression of urbanization, light pollution is becoming an inevitable risk factor for NAFLD. However, the role of light pollution on NAFLD is insufficiently understood, and the underlying mechanism remains unclear. The present study explored effects of constant light exposure on NAFLD and elucidated its related mechanisms. METHODS Thirty-two male Sprague Dawley rats were divided into four groups (n = 8 each): (i) rats on a normal diet exposed to standard light-dark cycle (ND-LD); (ii) rats on a normal diet exposed to constant light (ND-LL); (iii) rats on a high-fat diet exposed to standard light-dark cycle (HFD-LD); and (iv) and rats on a high-fat diet exposed to constant light (HFD-LL). After 12 weeks of treatment, rats were sacrificed and pathophysiological assessments were performed. Targeted lipidomics was used to measure sphingolipids, including ceramides, glucosylceramides, and lactosylceramides, sphingomyelins, and sphingosine-1-phosphates in plasma and liver tissues. RESULTS In normal chow rats, constant light exposure led to glucose abnormalities and dyslipidemia. In high-fat-fed rats, constant light exposure exacerbated glucose abnormalities, dyslipidemia, insulin resistance, and inflammation and aggravated steatohepatitis. Compared with HFD-LD rats, HFD-LL had decreased plasma sphingosine-1-phosphate and elevated liver concentrations of total ceramide and specific ceramide species (ceramide d18:0/24:0, ceramide d18:1/22:0, ceramide d18:1/24:0, and ceramide d18:1/24:1), which were associated with increased hepatocyte apoptosis. CONCLUSIONS Constant light exposure causes dysregulation of sphingolipids and promotes steatohepatitis in high-fat-fed rats.
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Affiliation(s)
- Fangzhi Yue
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ke Xia
- Department of Cardiology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lin Wei
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lin Xing
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shanyu Wu
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ying Shi
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xingwei Xiang
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ryan Russell
- Department of Health and Human Performance, College of Health Professions, University of Texas Rio Grande Valley, Brownsville, Texas, USA
| | - Dongmei Zhang
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
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