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Qi D, Huang D, Ba M, Xuan S, Si H, Lu D, Pei X, Zhang W, Huang S, Li Z. Long-term high fructose intake reprograms the circadian transcriptome and disrupts homeostasis in mouse extra-orbital lacrimal glands. Exp Eye Res 2024; 246:110008. [PMID: 39025460 DOI: 10.1016/j.exer.2024.110008] [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: 10/30/2023] [Revised: 07/03/2024] [Accepted: 07/15/2024] [Indexed: 07/20/2024]
Abstract
This study aims to explore the effects of long-term high fructose intake (LHFI) on the structure, functionality, and physiological homeostasis of mouse extra-orbital lacrimal glands (ELGs), a critical component of ocular health. Our findings reveal significant reprogramming of the circadian transcriptome in ELGs following LHFI, alongside the activation of specific inflammatory pathways, as well as metabolic and neural pathways. Notably, LHFI resulted in increased inflammatory infiltration, enhanced lipid deposition, and reduced nerve fiber density in ELGs compared to controls. Functional assessments indicated a marked reduction in lacrimal secretion following cholinergic stimulation in LHFI-treated mice, suggesting impaired gland function. Overall, our results suggest that LHFI disrupts lacrimal gland homeostasis, potentially leading to dry eye disease by altering its structure and secretory function. These insights underscore the profound impact of dietary choices on ocular health and highlight the need for strategies to mitigate these risks.
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Affiliation(s)
- Di Qi
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, 450000, China
| | - Duliurui Huang
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, 450000, China
| | - Mengru Ba
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, 450000, China
| | - Shuting Xuan
- Department of Ophthalmology, Henan University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, 450000, China
| | - Hongli Si
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, 450000, China
| | - Dingli Lu
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, 450000, China
| | - Xiaoting Pei
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, 450000, China
| | - Wenxiao Zhang
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, 450000, China
| | - Shenzhen Huang
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, 450000, China
| | - Zhijie Li
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, 450000, China.
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El-Akabawy G, El-Kersh SOF, El-Kersh AOFO, Amin SN, Rashed LA, Abdel Latif N, Elshamey A, Abdallah MAAEM, Saleh IG, Hein ZM, El-Serafi I, Eid N. Dental pulp stem cells ameliorate D-galactose-induced cardiac ageing in rats. PeerJ 2024; 12:e17299. [PMID: 38799055 PMCID: PMC11127642 DOI: 10.7717/peerj.17299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/03/2024] [Indexed: 05/29/2024] Open
Abstract
Background Ageing is a key risk factor for cardiovascular disease and is linked to several alterations in cardiac structure and function, including left ventricular hypertrophy and increased cardiomyocyte volume, as well as a decline in the number of cardiomyocytes and ventricular dysfunction, emphasizing the pathological impacts of cardiomyocyte ageing. Dental pulp stem cells (DPSCs) are promising as a cellular therapeutic source due to their minimally invasive surgical approach and remarkable proliferative ability. Aim This study is the first to investigate the outcomes of the systemic transplantation of DPSCs in a D-galactose (D-gal)-induced rat model of cardiac ageing. Methods. Thirty 9-week-old Sprague-Dawley male rats were randomly assigned into three groups: control, ageing (D-gal), and transplanted groups (D-gal + DPSCs). D-gal (300 mg/kg/day) was administered intraperitoneally daily for 8 weeks. The rats in the transplantation group were intravenously injected with DPSCs at a dose of 1 × 106 once every 2 weeks. Results The transplanted cells migrated to the heart, differentiated into cardiomyocytes, improved cardiac function, upregulated Sirt1 expression, exerted antioxidative effects, modulated connexin-43 expression, attenuated cardiac histopathological alterations, and had anti-senescent and anti-apoptotic effects. Conclusion Our results reveal the beneficial effects of DPSC transplantation in a cardiac ageing rat model, suggesting their potential as a viable cell therapy for ageing hearts.
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Affiliation(s)
- Gehan El-Akabawy
- Department of Basic Medical Sciences, College of Medicine, Ajman University, Ajman, United Arab Emirates
- Centre of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
- Department of Anatomy and Embryology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
| | | | | | - Shaimaa Nasr Amin
- Department of Anatomy, Physiology and Biochemistry, Faculty of Medicine, The Hashemite University, Zarqa, Jordan
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Laila Ahmed Rashed
- Department of Medical Biochemistry, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Noha Abdel Latif
- Department of Medical Pharmacology, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Medical Pharmacology, Armed Forces College of Medicine, Cairo, Egypt
| | - Ahmed Elshamey
- Samanoud General Hospital, Samannoud City, Samanoud, Gharbia, Egypt
| | | | - Ibrahim G. Saleh
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
- Department of Clinical Pharmacy and Pharmacy Practice, Faculty of Pharmacy, Sinai University, Kantra, Ismailia, Egypt
| | - Zaw Myo Hein
- Department of Basic Medical Sciences, College of Medicine, Ajman University, Ajman, United Arab Emirates
- Centre of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
| | - Ibrahim El-Serafi
- Department of Basic Medical Sciences, College of Medicine, Ajman University, Ajman, United Arab Emirates
| | - Nabil Eid
- Department of Anatomy, Division of Human Biology, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
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Liu J, Si H, Huang D, Lu D, Zou S, Qi D, Pei X, Huang S, Li Z. Mechanisms of Extraorbital Lacrimal Gland Aging in Mice: An Integrative Analysis of the Temporal Transcriptome. Invest Ophthalmol Vis Sci 2023; 64:18. [PMID: 37695604 PMCID: PMC10501490 DOI: 10.1167/iovs.64.12.18] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 08/16/2023] [Indexed: 09/12/2023] Open
Abstract
Purpose This study used high-throughput RNA sequencing (RNA-Seq) and bioinformatics analysis to investigate the altered transcriptome profile of aging lacrimal glands in mice that occurs over the course of a 24-hour cycle. Methods Male C57BL/6J mice aged 12 weeks (young) and 20 months (aging) were housed in a pathogen-free setting with a 12-hour light/12-hour dark cycle. Throughout a 24-hour cycle, mouse extraorbital lacrimal glands (ELGs) were collected at eight time points at three-hour intervals. To prepare for the high-throughput RNA-Seq, whole mRNA was extracted. Differentially expressed genes (DEGs) in the young and aging groups were subjected to bioinformatic analysis based on diurnal patterns. Furthermore, the cell populations in which significant DEGs express and signaling pathways occur were validated at the single-cell RNA sequencing (scRNA-seq) level. Results The total transcriptome composition was significantly altered in aging ELGs compared with that in young mouse ELGs at eight time points during the 24-hour cycle, with 864 upregulated and 228 downregulated DEGs, which were primarily enriched in inflammatory pathways. Further comparative analysis of the point-to-point transcriptome revealed that aging ELGs underwent alterations in the temporal transcriptome profile in several pathways, including the inflammation-related, metabolism-related, mitochondrial bioenergetic function-associated, synaptome neural activity-associated, cell processes-associated, DNA processing-associated and fibrosis-associated pathways. Most of these pathways occurred separately in distinct cell populations. Conclusions Transcriptome profiles of aging lacrimal glands undergo considerable diurnal time-dependent changes; this finding offers a comprehensive source of information to better understand the pathophysiology of lacrimal gland aging and its underlying mechanisms.
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Affiliation(s)
- Jiangman Liu
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Hongli Si
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Duliurui Huang
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Dingli Lu
- Henan Eye Institute, Henan Eye Hospital, and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Sen Zou
- Henan Eye Institute, Henan Eye Hospital, and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Di Qi
- Henan Eye Institute, Henan Eye Hospital, and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Xiaoting Pei
- Henan Eye Institute, Henan Eye Hospital, and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Shenzhen Huang
- Henan Eye Institute, Henan Eye Hospital, and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Zhijie Li
- Henan Eye Institute, Henan Eye Hospital, and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
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Huang S, Si H, Liu J, Qi D, Pei X, Lu D, Zou S, Li Z. Sleep Loss Causes Dysfunction in Murine Extraorbital Lacrimal Glands. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 35731510 PMCID: PMC9233287 DOI: 10.1167/iovs.63.6.19] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose Sleep loss markedly affects the structure and function of the lacrimal gland and may cause ocular surface disease as a common public health problem. This study aims to investigate the circadian disturbance caused by sleep loss leading to dysfunction of extraorbital lacrimal glands (ELGs). Methods A mouse sleep deprivation (SD) model for sleep loss studies was built in C57BL/6J male mice. After four weeks, the ELGs were collected at three-hour intervals during a 24-hour period. The Jonckheere-Terpstra-Kendall algorithm was used to determine the composition, phase, and rhythmicity of transcriptomic profiles in ELGs. Furthermore, we compared the non-sleep-deprived and SD-treated mouse ELG (i) reactive oxygen species (ROS) by fluorescein staining, (ii) DNA damage by immunostaining for γ-H2Ax, and (iii) circadian migration of immune cells by immunostaining for CD4, CD8, γδ-TCR, CD64, and CX3CR1. Finally, we also evaluated (i) the locomotor activity and core body temperature rhythm of mice and (ii) the mass, cell size, and tear secretion of the ELGs. Results SD dramatically altered the composition and phase-associated functional enrichment of the circadian transcriptome, immune cell trafficking, metabolism, cell differentiation, and neural secretory activities of mouse ELGs. Additionally, SD caused the ROS accumulation and consequent DNA damage in the ELGs, and the ELG dysfunction caused by SD was irreversible. Conclusions SD damages the structure, function, and diurnal oscillations of ELGs. These results highlight comprehensive characterization of insufficient sleep–affected ELG circadian transcriptome that may provide a new therapeutic approach to counteract the effects of SD on ELG function.
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Affiliation(s)
- Shenzhen Huang
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Hongli Si
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Jiangman Liu
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Di Qi
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaoting Pei
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Dingli Lu
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Sen Zou
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhijie Li
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
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Zou S, Jiao X, Liu J, Qi D, Pei X, Lu D, Huang S, Li Z. High-Fat Nutritional Challenge Reshapes Circadian Signatures in Murine Extraorbital Lacrimal Glands. Invest Ophthalmol Vis Sci 2022; 63:23. [PMID: 35588356 PMCID: PMC9123521 DOI: 10.1167/iovs.63.5.23] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose A high-fat diet (HFD) increases the risk of developing many systemic diseases; however, the effects of high fat intake on lacrimal gland functions and the molecular mechanisms underlying these effects are unknown. We explored the effects of an HFD on the circadian rhythms of the extraorbital lacrimal glands (ELGs). Methods Male C57BL/6J mice maintained on a 12/12-hour light/dark cycle were fed an ad libitum HFD or normal chow (NC) for 2 weeks. The ELGs were collected from euthanized animals every 3 hours throughout the circadian cycle (24 hours). Using high-throughput RNA-sequencing (RNA-Seq), we studied the circadian transcriptomic profile of the ELGs. Circadian oscillations in cell size, secretion response, lipid deposition, and immune cell trafficking of the ELGs were also analyzed. Results An HFD modulated the circadian transcriptomic profile of the ELGs, including the composition, phase, and amplitude of cyclical transcript oscillations, and affected the associated signaling pathways at spatiotemporal levels. HFD feeding significantly altered the normal rhythmic oscillations of ELG cell size, immune cell trafficking, secretion response, and lipid deposition. After dietary reversal in HFD-fed animals, the activity, core temperature, and lipid accumulation in lacrimal glands recovered partially to the level of NC-fed animals. However, the average cell size of the ELGs, the recruitment of immune cells, and the rhythm of lacrimal secretion did not return to the levels of the NC-fed group. Conclusions HFD perturbation interferes with the cyclical transcriptomic profile, cell size, immune cell trafficking, and secretion function of the ELGs with a strikingly high sensitivity.
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Affiliation(s)
- Sen Zou
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Xinwei Jiao
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Jiangman Liu
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Di Qi
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Xiaoting Pei
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Dingli Lu
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Shenzhen Huang
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
| | - Zhijie Li
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou City, China
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Domarecka E, Kalcioglu MT, Mutlu A, Özgür A, Smit J, Olze H, Szczepek AJ. Reporting Data on Auditory Brainstem Responses (ABR) in Rats: Recommendations Based on Review of Experimental Protocols and Literature. Brain Sci 2021; 11:brainsci11121596. [PMID: 34942898 PMCID: PMC8699229 DOI: 10.3390/brainsci11121596] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
Research in hearing science is accelerating, and a wealth of data concerning auditory brainstem responses (ABR) in various animal models is published in peer-reviewed journals every year. Recently, we reviewed studies using ABR measurements in tinnitus rat models. We found significant discrepancies in the outcomes of these studies, some due to different research approaches and others due to different methodologies. Thus, the present work aimed to collect comprehensive information on all factors influencing ABR recordings in rats and compile recommendations on ABR data reporting. A questionnaire with queries about animal husbandry, transfer, handling, and the exact test conditions before, during, and after ABR recordings was sent to 125 researchers who published the relevant studies between 2015 and 2021. Eighteen researchers provided detailed answers on factors related to ABR measurements. Based on the analysis of the returned questionnaires, we identified three domains reflecting animal-, equipment-, and experiment-dependent factors that might influence the ABR outcome, thus requiring reporting in published research. The analysis of survey results led to the compilation of recommendations for reporting ABR outcomes supported by a literature review. Following these recommendations should facilitate comparative and meta-analyses of ABR results provided by various research groups.
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Affiliation(s)
- Ewa Domarecka
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, 10117 Berlin, Germany;
- Correspondence: (E.D.); (A.J.S.)
| | - Mahmut Tayyar Kalcioglu
- Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, Istanbul Medeniyet University, 34720 Istanbul, Turkey; (M.T.K.); (A.M.)
- Otorhinolaryngology Clinic, Goztepe Prof. Dr. Suleyman Yalcin City Hospital, Kadikoy, 34722 Istanbul, Turkey
| | - Ahmet Mutlu
- Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, Istanbul Medeniyet University, 34720 Istanbul, Turkey; (M.T.K.); (A.M.)
- Otorhinolaryngology Clinic, Goztepe Prof. Dr. Suleyman Yalcin City Hospital, Kadikoy, 34722 Istanbul, Turkey
| | - Abdulkadir Özgür
- Department of Otorhinolaryngology, İstanbul Yeni Yuzyil University Gaziosmanpaşa Hospital, 34245 Istanbul, Turkey;
| | - Jasper Smit
- Zuyderland Medical Center, Department of Otorhinolaryngology, Head and Neck Surgery, 6419 PC Heerlen, The Netherlands;
| | - Heidi Olze
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, 10117 Berlin, Germany;
| | - Agnieszka J. Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, 10117 Berlin, Germany;
- Faculty of Medicine and Health Sciences, University of Zielona Góra, 65-046 Zielona Góra, Poland
- Correspondence: (E.D.); (A.J.S.)
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He J, Jiao X, Sun X, Huang Y, Xu P, Xue Y, Fu T, Liu J, Li Z. Short-Term High Fructose Intake Impairs Diurnal Oscillations in the Murine Cornea. Invest Ophthalmol Vis Sci 2021; 62:22. [PMID: 34415987 PMCID: PMC8383902 DOI: 10.1167/iovs.62.10.22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/14/2021] [Indexed: 12/11/2022] Open
Abstract
Purpose Endogenous and exogenous stressors, including nutritional challenges, may alter circadian rhythms in the cornea. This study aimed to determine the effects of high fructose intake (HFI) on circadian homeostasis in murine cornea. Methods Corneas of male C57BL/6J mice subjected to 10 days of HFI (15% fructose in drinking water) were collected at 3-hour intervals over a 24-hour circadian cycle. Total extracted RNA was subjected to high-throughput RNA sequencing. Rhythmic transcriptional data were analyzed to determine the phase, rhythmicity, unique signature, metabolic pathways, and cell signaling pathways of transcripts with temporally coordinated expression. Corneas of HFI mice were collected for whole-mounted techniques after immunofluorescent staining to quantify mitotic cell number in the epithelium and trafficking of neutrophils and γδ-T cells to the limbal region over a circadian cycle. Results HFI significantly reprogrammed the circadian transcriptomic profiles of the normal cornea and reorganized unique temporal and clustering enrichment pathways, but did not affect core-clock machinery. HFI altered the distribution pattern and number of corneal epithelial mitotic cells and enhanced recruitment of neutrophils and γδ-T cell immune cells to the limbus across a circadian cycle. Cell cycle, immune function, metabolic processes, and neuronal-related transcription and associated pathways were altered in the corneas of HFI mice. Conclusions HFI significantly reprograms diurnal oscillations in the cornea based on temporal and spatial distributions of epithelial mitosis, immune cell trafficking, and cell signaling pathways. Our findings reveal novel molecular targets for treating pathologic alterations in the cornea after HFI.
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Affiliation(s)
- Jingxin He
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xinwei Jiao
- Department of Pathophysiology, Jinan University Medical School, Guangzhou, China
| | - Xin Sun
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yijia Huang
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Pengyang Xu
- Department of Pathophysiology, Jinan University Medical School, Guangzhou, China
| | - Yunxia Xue
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
| | - Ting Fu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
| | - Jun Liu
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
| | - Zhijie Li
- International Ocular Surface Research Center, Institute of Ophthalmology and Key Laboratory for Regenerative Medicine, Jinan University, Guangzhou, China
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
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Light cycle phase advance as a model for jet lag reprograms the circadian rhythms of murine extraorbital lacrimal glands. Ocul Surf 2021; 20:95-114. [PMID: 33582293 DOI: 10.1016/j.jtos.2021.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/07/2021] [Accepted: 02/01/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE Jet lag causes a disruption in physiological rhythms in humans. This study aims to explore the extent to which jet lag affects the circadian rhythmicity in the lacrimal glands. METHODS C57BL/6J mice were subjected to a 12-h light/12-h dark (LD) cycle and an 8-h advanced LD schedule as a model for jet lag. On day 5 after the LD advance, the extraorbital lacrimal glands (ELGs) were collected at 3-h intervals during a 24-h cycle. Total mRNA was extracted from normal and advanced LD-treated ELGs and assayed using high-throughput RNA sequencing. The rhythmic transcripts were identified, analyzed, and visualized by bioinformatics techniques. Finally, (i) animal behavior; (ii) the mass, cell size, and secretion response of ELGs; and (iii) circadian migration of immune cells to ELGs were also assayed. RESULTS Jet lag treatment drastically altered the phase and composition of the rhythmic transcripts compared to that of normal ELGs. The key biological processes, signaling pathways, and protein-protein association networks were also dramatically altered in a spatiotemporal pattern. Furthermore, the circadian migration of neutrophils, T cells, B cells, and macrophages to the ELGs increased and shifted later by 6-h. Finally, the circadian rhythms of the ELGs with respect to mass, cell size, and secretion response were also impaired in jet lag-treated animals. CONCLUSIONS Jet lag impairs the circadian rhythm of the transcriptomic profile, structure, and secretion function of the lacrimal glands. This information provides novel insight into the negative effects of jet lag on ELGs.
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In Vivo Evaluation of a Subcutaneously Injectable Implant with a Low-Power Photoplethysmography ASIC for Animal Monitoring. SENSORS 2020; 20:s20247335. [PMID: 33371238 PMCID: PMC7766824 DOI: 10.3390/s20247335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/14/2020] [Accepted: 12/17/2020] [Indexed: 11/24/2022]
Abstract
Photoplethysmography is an extensively-used, portable, and noninvasive technique for measuring vital parameters such as heart rate, respiration rate, and blood pressure. The deployment of this technology in veterinary medicine has been hindered by the challenges in effective transmission of light presented by the thick layer of skin and fur of the animal. We propose an injectable capsule system to circumvent these limitations by accessing the subcutaneous tissue to enable reliable signal acquisition even with lower light brightness. In addition to the reduction of power usage, the injection of the capsule offers a less invasive alternative to surgical implantation. Our current prototype combines two application-specific integrated circuits (ASICs) with a microcontroller and interfaces with a commercial light emitting diode (LED) and photodetector pair. These ASICs implement a signal-conditioning analog front end circuit and a frequency-shift keying (FSK) transmitter respectively. The small footprint of the ASICs is the key in the integration of the complete system inside a 40-mm long glass tube with an inner diameter of 4 mm, which enables its injection using a custom syringe similar to the ones used with microchip implants for animal identification. The recorded data is transferred wirelessly to a computer for post-processing by means of the integrated FSK transmitter and a software-defined radio. Our optimized LED duty cycle of 0.4% at a sampling rate of 200 Hz minimizes the contribution of the LED driver (only 0.8 mW including the front-end circuitry) to the total power consumption of the system. This will allow longer recording periods between the charging cycles of the batteries, which is critical given the very limited space inside the capsule. In this work, we demonstrate the wireless operation of the injectable system with a human subject holding the sensor between the fingers and the in vivo functionality of the subcutaneous sensing on a pilot study performed on anesthetized rat subjects.
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10
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Jiao X, Lu D, Pei X, Qi D, Huang S, Song Z, Gu J, Li Z. Type 1 diabetes mellitus impairs diurnal oscillations in murine extraorbital lacrimal glands. Ocul Surf 2020; 18:438-452. [PMID: 32360784 DOI: 10.1016/j.jtos.2020.04.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 01/09/2023]
Abstract
PURPOSE People with diabetes are at high risk of lacrimal gland dysfunction, but the underlying mechanism is not well understood. In this study, we determined how type 1 diabetes mellitus (T1DM) influences circadian homeostasis of the murine extraorbital lacrimal glands (ELGs). METHODS A T1DM animal model was established by systemic streptozotocin injection in C57BL/6J mice. After 5 weeks, ELGs were collected at 3-h intervals over a 24-h circadian cycle. Total extracted RNA was subjected to high-throughput RNA sequencing, and rhythmic transcriptional data were evaluated using the Jonckheere-Terpstra-Kendall algorithm, Kyoto Encyclopedia of Genes and Genomes pathway analysis, Phase Set Enrichment Analysis, and time series cluster analysis to determine the phase, rhythmicity, and unique signature of the transcripts over temporally coordinated expression. Additionally, mass, cell size, histology, and tear secretion of the ELGs were evaluated. RESULTS T1DM globally altered the composition of the ELG transcriptome. Specifically, T1DM significantly reprogrammed the circadian transcriptomic profiles of normal ELGs and reorganized core clock machinery. Unique temporal and clustering enrichment pathways were also rewired by T1DM. Finally, normal daily rhythms of mass, cell size, and tear secretion of mouse ELGs were significantly impaired by streptozotocin-induced diabetes. CONCLUSIONS T1DM significantly reprograms the diurnal oscillations of the lacrimal glands and impairs their structure and tear secretion. This information may reveal potential targets for improving lacrimal gland dysfunction in patients with diabetes.
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Affiliation(s)
- Xinwei Jiao
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Dingli Lu
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Xiaoting Pei
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Di Qi
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Shenzhen Huang
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Zongming Song
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Jianqin Gu
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China
| | - Zhijie Li
- Henan Eye Institute, Henan Eye Hospital and Henan Key Laboratory of Ophthalmology and Visual Science, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, People's Hospital of Henan University, Zhengzhou, China.
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de Vrind VA, Rozeboom A, Wolterink‐Donselaar IG, Luijendijk‐Berg MC, Adan RA. Effects of GABA and Leptin Receptor-Expressing Neurons in the Lateral Hypothalamus on Feeding, Locomotion, and Thermogenesis. Obesity (Silver Spring) 2019; 27:1123-1132. [PMID: 31087767 PMCID: PMC6617814 DOI: 10.1002/oby.22495] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/28/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The lateral hypothalamus (LH) is known for its role in feeding, and it also regulates other aspects of energy homeostasis. How genetically defined LH neuronal subpopulations mediate LH effects on energy homeostasis remains poorly understood. The behavioral effects of chemogenetically activating LH gamma-aminobutyric acid (GABA) and the more selective population of LH GABA neurons that coexpress the leptin receptor (LepR) were compared. METHODS LepR-cre and VGAT-cre mice were injected with AAV5-hSyn-DIO-hM3DGq-mCherry in the LH. The behavioral effects of LH GABA or LH LepR neuronal activation on feeding, locomotion, thermogenesis, and body weight were assessed. RESULTS The activation of LH GABA neurons increased body temperature (P ≤ 0.008) and decreased body weight (P ≤ 0.01) despite decreased locomotor activity (P = 0.03) and transiently increased chow intake (P ≤ 0.009). Also, similar to other studies, this study found that activation of LH GABA neurons induced gnawing on both food and nonfood (P = 0.001) items. Activation of LH LepR neurons decreased body weight (P ≤ 0.01) and chow intake when presented on the cage floor (P ≤ 0.04) but not when presented in the cage top and increased locomotor activity (P = 0.002) and body temperature (P = 0.03). CONCLUSIONS LH LepR neurons are a subset of LH GABA neurons, and LH LepR activation more specifically regulates energy homeostasis to promote a negative energy balance.
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Affiliation(s)
- Véronne A.J. de Vrind
- Brain Center Rudolf Magnus, Department of Translational NeuroscienceUniversity Medical Center Utrecht and University UtrechtUtrechtThe Netherlands
| | - Annemieke Rozeboom
- Brain Center Rudolf Magnus, Department of Translational NeuroscienceUniversity Medical Center Utrecht and University UtrechtUtrechtThe Netherlands
| | - Inge G. Wolterink‐Donselaar
- Brain Center Rudolf Magnus, Department of Translational NeuroscienceUniversity Medical Center Utrecht and University UtrechtUtrechtThe Netherlands
| | - Mieneke C.M. Luijendijk‐Berg
- Brain Center Rudolf Magnus, Department of Translational NeuroscienceUniversity Medical Center Utrecht and University UtrechtUtrechtThe Netherlands
| | - Roger A.H. Adan
- Brain Center Rudolf Magnus, Department of Translational NeuroscienceUniversity Medical Center Utrecht and University UtrechtUtrechtThe Netherlands
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of GothenburgGothenburgSweden
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12
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Tejada de Rink MM, Naumann U, Kollmar R, Schwab S, Dietel B, Harada H, Tauchi M. A Single Injection of N-Oleoyldopamine, an Endogenous Agonist for Transient Receptor Potential Vanilloid-1, Induced Brain Hypothermia, but No Neuroprotective Effects in Experimentally Induced Cerebral Ischemia in Rats. Ther Hypothermia Temp Manag 2019; 10:91-101. [PMID: 31084468 DOI: 10.1089/ther.2018.0036] [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: 10/26/2022] Open
Abstract
Targeted temperature management, or therapeutic hypothermia, is a potent neuroprotective approach after ischemic brain injury. Hypothermia should be induced as soon as possible after the onset of acute stroke to assure better outcomes. Accordingly, drugs with a fast-acting hypothermic effect sustainable through the period of emergency transportation to hospital would have clinical advantages. Activation of the transient receptor potential vanilloid-1 (TRPV1) can induce hypothermia. Our immunohistochemical investigations confirmed that TRPV1 was distributed to perivascular and periventricular regions of the rat brain, where TRPV1 can be easily detected by TRPV1 agonists. An endogenous TRPV1 selective agonist, N-oleoyldopamine (OLDA), and a synthetic antagonist, AMG 9810, were injected intraperitoneally into healthy adult male Wister rats, and brain and core temperatures and gross motor activities were monitored. Comparison with baseline temperatures showed that TRPV1 injection immediately induced mild hypothermia (p < 0.05 in brain and p < 0.01 in body), and AMG 9810 induced immediate mild hyperthermia (not significant). However, the OLDA-induced hypothermia did not decrease lesion volume after middle carotid artery occlusion in rats. Relative to vehicle, OLDA yielded poorer outcomes and AMG 9810 yielded better outcomes in neurological scores and lesion size. Our study showed that, as an agonist of TRPV1, OLDA has suitable hypothermia-inducing properties, but did not decrease lesion volume. Therefore, the search for novel TRPV1 agonists and/or antagonists providing hypothermia and neuroprotection should continue. Further investigations should also target OLDA-induced transient hypothermia combined with long-term hypothermia maintenance with surface cooling, which mimics the anticipated clinical use of this class of drug.
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Affiliation(s)
- Maria Mercedes Tejada de Rink
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Ulrike Naumann
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Rainer Kollmar
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stefan Schwab
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Barbara Dietel
- Department of Medicine 2-Cardiology and Angiology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Hideki Harada
- Neuroanesthesia Research Laboratory, Cognitive and Molecular Institute of Brain Diseases, Kurume University School of Medicine, Kurume, Japan.,Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
| | - Miyuki Tauchi
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Department of Medicine 2-Cardiology and Angiology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Department of Molecular Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
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Zhang W, Yang B, Weng H, Liu T, Shi L, Yu P, So KF, Qu Y, Zhou L. Wheel Running Improves Motor Function and Spinal Cord Plasticity in Mice With Genetic Absence of the Corticospinal Tract. Front Cell Neurosci 2019; 13:106. [PMID: 30941019 PMCID: PMC6433830 DOI: 10.3389/fncel.2019.00106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 03/04/2019] [Indexed: 12/13/2022] Open
Abstract
Our previous studies showed that mutant mice with congenital absence of the corticospinal tract (CST) undergo spontaneous remodeling of motor networks to partially compensate for absent CST function. Here, we asked whether voluntary wheel running could further improve locomotor plasticity in CST-deficient mice. Adult mutant mice were randomly allocated to a “runners” group with free access to a wheel, or a “non-runners” group with no access to a wheel. In comparison with non-runners, there was a significant motor improvement including fine movement, grip strength, decreased footslip errors in runners after 8-week training, which was supported by the elevated amplitude of electromyography recording and increased neuromuscular junctions in the biceps. In runners, terminal ramifications of monoaminergic and rubrospinal descending axons were significantly increased in spinal segments after 12 weeks of exercise compared to non-runners. 5-ethynyl-2′-deoxyuridine (EDU) labeling showed that proliferating cells, 90% of which were Olig2-positive oligodendrocyte progenitors, were 4.8-fold more abundant in runners than in non-runners. In 8-week runners, RNAseq analysis of spinal samples identified 404 genes up-regulated and 398 genes down-regulated, and 69 differently expressed genes involved in signal transduction, among which the NF-κB, PI3K-Akt and cyclic AMP (cAMP) signaling were three top pathways. Twelve-week training induced a significant elevation of postsynaptic density protein 95 (PSD95), synaptophysin 38 and myelin basic protein (MBP), but not of brain derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and insulin like growth factor-1 (IGF-1). Thus, locomotor training activates multiple signaling pathways, contributes to neural plasticity and functional improvement, and might palliate locomotor deficits in patients.
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Affiliation(s)
- Wei Zhang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Bin Yang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Huandi Weng
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Tao Liu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Lingling Shi
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Panpan Yu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Kwok-Fai So
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Yibo Qu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Libing Zhou
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China.,Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu, China.,Key Laboratory of Neuroscience, School of Basic Medical Sciences, Institute of Neuroscience, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
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14
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Chapon PA, Bulla J, Besnard S, Gauthier A, Bessot N. Performances assessment of Anipill
®
device prototype designed for continuous temperature monitoring. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aad440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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15
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Tse K, Sillito R, Keerie A, Collier R, Grant C, Karp NA, Vickers C, Chapman K, Armstrong JD, Redfern WS. Pharmacological validation of individual animal locomotion, temperature and behavioural analysis in group-housed rats using a novel automated home cage analysis system: A comparison with the modified Irwin test. J Pharmacol Toxicol Methods 2018; 94:1-13. [PMID: 29614333 DOI: 10.1016/j.vascn.2018.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 02/07/2018] [Accepted: 03/28/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND The ActualHCA™ system continuously monitors the activity, temperature and behavior of group-housed rats without invasive surgery. The system was validated to detect the contrasting effects of sedative and stimulant test agents (chlorpromazine, clonidine and amphetamine), and compared with the modified Irwin test (mIT) with rectal temperature measurements. METHODS Six male Han Wistar rats per group were used to assess each test agent and vehicle controls in separate ActualHCA™ recordings and mIT. The mIT was undertaken at 15, 30 mins, 1, 2, 4 and 24 h post-dose. ActualHCA™ recorded continuously for 24 h post-dose under 3 experimental conditions: dosed during light phase, dark phase, and light phase with a scheduled cage change at the time of peak effects determined by mIT. RESULTS ActualHCA™ detected an increase stimulated activity from the cage change at 1-2 h post-dose which was obliterated by chlorpromazine and clonidine. Amphetamine increased activity up to 4 h post-dose in all conditions. Temperature from ActualHCA™ was affected by all test agents in all conditions. The mIT showed effects on all 3 test agents up to 4 h post-dose, with maximal effects at 1-2 h post-dose. The maximal effects on temperature from ActualHCA™ differed from mIT. Delayed effects on activity were detected by ActualHCA™, but not on mIT. CONCLUSIONS Continuous monitoring has the advantage of capturing effects over time that may be missed with manual tests using pre-determined time points. This automated behavioural system does not replace the need for conventional methods but could be implemented simultaneously to improve our understanding of behavioural pharmacology.
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Affiliation(s)
- Karen Tse
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK.
| | - Rowland Sillito
- Actual Analytics Ltd, Appleton Tower, 10 Crichton Street, Edinburgh EH8 9LE, UK
| | - Amy Keerie
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Rachel Collier
- Laboratory Animal Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Claire Grant
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Alderley Park, Cheshire SK10 4TG, UK
| | - Natasha A Karp
- Quantitative Biology, Discovery Science, IMED Biotech Unit, AstraZeneca, Cambridge Science Park, Cambridge CB4 0WG, UK
| | - Cathy Vickers
- NC3Rs, Gibbs Building, 215 Euston Road, London NW1 2BE, UK
| | | | - J Douglas Armstrong
- Actual Analytics Ltd, Appleton Tower, 10 Crichton Street, Edinburgh EH8 9LE, UK; School of Informatics, University of Edinburgh, Appleton Tower, 11 Crichton Street, Edinburgh EH8 9LE, UK
| | - William S Redfern
- Safety and ADME Translational Sciences, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Babraham Research Campus, Cambridge CB22 3AT, UK
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16
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Mitchell SE, Delville C, Konstantopedos P, Derous D, Green CL, Wang Y, Han JDJ, Promislow DEL, Douglas A, Chen L, Lusseau D, Speakman JR. The effects of graded levels of calorie restriction: V. Impact of short term calorie and protein restriction on physical activity in the C57BL/6 mouse. Oncotarget 2017; 7:19147-70. [PMID: 27007156 PMCID: PMC4991372 DOI: 10.18632/oncotarget.8158] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 02/28/2016] [Indexed: 12/15/2022] Open
Abstract
Calorie restriction (CR) delays the onset of age-related disease and extends lifespan in a number of species. When faced with reduced energy supply animals need to lower energy demands, which may be achieved in part by reducing physical activity (PA). We monitored changes in PA using implanted transmitters in male C57BL/6 mice in response to graded levels of CR (10 to 40%) or matched levels of graded protein restriction (PR) for 3 months. Mice were fed at lights out and ad libitum controls were limited to dark-phase feeding (12AL) or 24hr/day. Total daily PA declined in a non-linear manner over the first 30 days of CR or PR, remaining stable thereafter. Total daily PA was not related to the level of CR or PR. Total daily PA over the last 20 days of restriction was related to circulating leptin, insulin, tumor necrosis factor-α (TNF-α) and insulin-like growth factor (IGF)-1 levels, measured after 3 months. Mice under restriction showed a high level of activity in the 2hrs before feeding (food anticipatory activity: FAA). FAA followed a complex pattern, peaking around day 20, falling on ∼day 37 then increasing again. FAA was also positively related to the level of restriction and inversely to leptin, insulin, TNF-α and IGF-1. Non-FAA, in contrast, declined over the period of restriction, generally more so in mice under greater restriction, thereby offsetting to some extent the increase in FAA. Mice under PR displayed no changes in PA over time or in comparison to 12AL, and showed no increase in FAA.
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Affiliation(s)
- Sharon E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Camille Delville
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Penelope Konstantopedos
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Davina Derous
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Cara L Green
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China
| | - Jing-Dong J Han
- Key Laboratory of Computational Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Daniel E L Promislow
- Department of Pathology and Department of Biology, University of Washington, Seattle, Washington, USA
| | - Alex Douglas
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Luonan Chen
- Key Laboratory of Systems Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - David Lusseau
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China
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Forebrain-selective AMPA-receptor antagonism guided by TARP γ-8 as an antiepileptic mechanism. Nat Med 2016; 22:1496-1501. [DOI: 10.1038/nm.4221] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 09/30/2016] [Indexed: 12/12/2022]
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18
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Stenblom EL, Egecioglu E, Montelius C, Ramachandran D, Bonn B, Weström B, Mansouri A, Langhans W, Erlanson-Albertsson C. Dietary thylakoids reduce visceral fat mass and increase expression of genes involved in intestinal fatty acid oxidation in high-fat fed rats. Am J Physiol Regul Integr Comp Physiol 2016; 311:R618-27. [PMID: 27488889 DOI: 10.1152/ajpregu.00212.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Thylakoids reduce body weight gain and body fat accumulation in rodents. This study investigated whether an enhanced oxidation of dietary fat-derived fatty acids in the intestine contributes to the thylakoid effects. Male Sprague-Dawley rats were fed a high-fat diet with (n = 8) or without thylakoids (n = 8) for 2 wk. Body weight, food intake, and body fat were measured, and intestinal mucosa was collected and analyzed. Quantitative real-time PCR was used to measure gene expression levels of key enzymes involved in fatty acid transport, fatty acid oxidation, and ketogenesis. Another set of thylakoid-treated (n = 10) and control rats (n = 10) went through indirect calorimetry. In the first experiment, thylakoid-treated rats (n = 8) accumulated 25% less visceral fat than controls. Furthermore, fatty acid translocase (Fat/Cd36), carnitine palmitoyltransferase 1a (Cpt1a), and mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (Hmgcs2) genes were upregulated in the jejunum of the thylakoid-treated group. In the second experiment, thylakoid-treated rats (n = 10) gained 17.5% less weight compared with controls and their respiratory quotient was lower, 0.86 compared with 0.91. Thylakoid-intake resulted in decreased food intake and did not cause steatorrhea. These results suggest that thylakoids stimulated intestinal fatty acid oxidation and ketogenesis, resulting in an increased ability of the intestine to handle dietary fat. The increased fatty acid oxidation and the resulting reduction in food intake may contribute to the reduced fat accumulation in thylakoid-treated animals.
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Affiliation(s)
- Eva-Lena Stenblom
- Department of Experimental Medical Science, Appetite Regulation Unit, Faculty of Medicine, Lund University, Lund, Sweden
| | - Emil Egecioglu
- Department of Experimental Medical Science, Appetite Regulation Unit, Faculty of Medicine, Lund University, Lund, Sweden
| | - Caroline Montelius
- Department of Experimental Medical Science, Appetite Regulation Unit, Faculty of Medicine, Lund University, Lund, Sweden
| | | | - Britta Bonn
- AstraZeneca, R&D Gothenburg, Mölndal, Sweden; and
| | - Björn Weström
- Department of Biology, Lund University, Lund, Sweden
| | - Abdelhak Mansouri
- Physiology and Behavior Laboratory, ETH Zürich, Schwerzenbach, Switzerland
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, ETH Zürich, Schwerzenbach, Switzerland
| | - Charlotte Erlanson-Albertsson
- Department of Experimental Medical Science, Appetite Regulation Unit, Faculty of Medicine, Lund University, Lund, Sweden;
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Ryan KM, Griffin ÉW, Ryan KJ, Tanveer R, Vanattou-Saifoudine N, McNamee EN, Fallon E, Heffernan S, Harkin A, Connor TJ. Clenbuterol activates the central IL-1 system via the β2-adrenoceptor without provoking inflammatory response related behaviours in rats. Brain Behav Immun 2016; 56:114-29. [PMID: 26928198 DOI: 10.1016/j.bbi.2016.02.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/18/2016] [Accepted: 02/25/2016] [Indexed: 01/09/2023] Open
Abstract
The long-acting, highly lipophilic, β2-adrenoceptor agonist clenbuterol may represent a suitable therapeutic agent for the treatment of neuroinflammation as it drives an anti-inflammatory response within the CNS. However, clenbuterol is also known to increase the expression of IL-1β in the brain, a potent neuromodulator that plays a role in provoking sickness related symptoms including anxiety and depression-related behaviours. Here we demonstrate that, compared to the immunological stimulus lipopolysaccharide (LPS, 250μg/kg), clenbuterol (0.5mg/kg) selectively up-regulates expression of the central IL-1 system resulting in a mild stress-like response which is accompanied by a reduction in locomotor activity and food consumption in rats. We provide further evidence that clenbuterol-induced activation of the central IL-1 system occurs in a controlled and selective manner in tandem with its negative regulators IL-1ra and IL-1RII. Furthermore, we demonstrate that peripheral β2-adrenoceptors mediate the suppression of locomotor activity and food consumption induced by clenbuterol and that these effects are not linked to the central induction of IL-1β. Moreover, despite increasing central IL-1β expression, chronic administration of clenbuterol (0.03mg/kg; twice daily for 21days) fails to induce anxiety or depressive-like behaviour in rats in contrast to reports of the ability of exogenously administered IL-1 to induce these symptoms in rodents. Overall, our findings suggest that clenbuterol or other selective β2-adrenoceptor agonists could have the potential to combat neuroinflammatory or neurodegenerative disorders without inducing unwanted symptoms of depression and anxiety.
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Affiliation(s)
- Karen M Ryan
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Éadaoin W Griffin
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Katie J Ryan
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Riffat Tanveer
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Natacha Vanattou-Saifoudine
- Neuropsychopharmacology Research Group, School of Pharmacy and Pharmaceutical Sciences & Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Eoin N McNamee
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Emer Fallon
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Sheena Heffernan
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
| | - Andrew Harkin
- Neuropsychopharmacology Research Group, School of Pharmacy and Pharmaceutical Sciences & Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
| | - Thomas J Connor
- Neuroimmunology Research Group, Trinity College Institute of Neuroscience, Department of Physiology & School of Medicine, Trinity College, Dublin 2, Ireland
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Jarosz PA. The Effect of Kappa Opioid Receptor Antagonism on Energy Expenditure in the Obese Zucker Rat. Biol Res Nurs 2016; 8:294-9. [PMID: 17456590 DOI: 10.1177/1099800406298774] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Food intake and, subsequently, body weight are influenced by endogenous opioids acting in the central nervous system. Agonists for the opioid receptor increase food intake, whereas antagonists reduce food intake. Body weight, however, is the result of food consumed and energy expended. Although much has been reported about the effect of opioid antagonism on food intake, less has been reported about its effect on energy expended. This study investigated the effect of selective antagonism of the kappa opioid receptor on food intake, body weight, and indicators of energy expenditure in male obese Zucker rats (n= 10). Energy expenditure was measured by indirect calorimetry, whereas general activity and body temperature were measured by implanted radio frequency telemetry. Central administration of 30 µg of the kappa opioid receptor (KOR) antagonist norbinaltorphamine resulted in a significant 34% reduction in food intake (p = .001), a small reduction in body weight, a reduction in resting energy expenditure (p = .06), a reduction in respiratory quotient (p = .06), a 14% reduction in general activity, and a reduction in core body temperature. Reduction in body weight as a result of KOR inhibition in this study was related to a decrease in food intake but not related to an increase in energy expended or activity.
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Affiliation(s)
- Patricia A Jarosz
- Wayne State University, College of Nursing, Detroit, Michigan 48202, USA.
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Mitchell SE, Delville C, Konstantopedos P, Derous D, Green CL, Chen L, Han JDJ, Wang Y, Promislow DEL, Douglas A, Lusseau D, Speakman JR. The effects of graded levels of calorie restriction: III. Impact of short term calorie and protein restriction on mean daily body temperature and torpor use in the C57BL/6 mouse. Oncotarget 2016; 6:18314-37. [PMID: 26286956 PMCID: PMC4621893 DOI: 10.18632/oncotarget.4506] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/13/2015] [Indexed: 11/30/2022] Open
Abstract
A commonly observed response in mammals to calorie restriction (CR) is reduced body temperature (Tb). We explored how the Tb of male C57BL/6 mice responded to graded CR (10 to 40%), compared to the response to equivalent levels of protein restriction (PR) over 3 months. Under CR there was a dynamic change in daily Tb over the first 30–35 days, which stabilized thereafter until day 70 after which a further decline was noted. The time to reach stability was dependent on restriction level. Body mass negatively correlated with Tb under ad libitum feeding and positively correlated under CR. The average Tb over the last 20 days was significantly related to the levels of body fat, structural tissue, leptin and insulin-like growth factor-1. Some mice, particularly those under higher levels of CR, showed periods of daily torpor later in the restriction period. None of the changes in Tb under CR were recapitulated by equivalent levels of PR. We conclude that changes in Tb under CR are a response only to the shortfall in calorie intake. The linear relationship between average Tb and the level of restriction supports the idea that Tb changes are an integral aspect of the lifespan effect.
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Affiliation(s)
- Sharon E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Camille Delville
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Penelope Konstantopedos
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Davina Derous
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Cara L Green
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Luonan Chen
- Key laboratory of Systems Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jing-Dong J Han
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China
| | - Daniel E L Promislow
- Department of Pathology, University of Washington at Seattle, Seattle, Washington, USA
| | - Alex Douglas
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - David Lusseau
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China
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Horvath G, Kekesi G, Petrovszki Z, Benedek G. Abnormal Motor Activity and Thermoregulation in a Schizophrenia Rat Model for Translational Science. PLoS One 2015; 10:e0143751. [PMID: 26629908 PMCID: PMC4667881 DOI: 10.1371/journal.pone.0143751] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/09/2015] [Indexed: 12/16/2022] Open
Abstract
Background Schizophrenia is accompanied by altered motor activity and abnormal thermoregulation; therefore, the presence of these symptoms can enhance the face validity of a schizophrenia animal model. The goal was to characterize these parameters in freely moving condition of a new substrain of rats showing several schizophrenia-related alterations. Methods Male Wistar rats were used: the new substrain housed individually (for four weeks) and treated subchronically with ketamine, and naive animals without any manipulations. Adult animals were implanted with E-Mitter transponders intraabdominally to record body temperature and locomotor activity continuously. The circadian rhythm of these parameters and the acute effects of changes in light conditions were analyzed under undisturbed circumstances, and the effects of different interventions (handling, bed changing or intraperitoneal vehicle injection) were also determined. Results Decreased motor activity with fragmented pattern was observed in the new substrain. However, these animals had higher body temperature during the active phase, and they showed wider range of its alterations, too. The changes in light conditions and different interventions produced blunted hyperactivity and altered body temperature responses in the new substrain. Poincaré plot analysis of body temperature revealed enhanced short- and long-term variabilities during the active phase compared to the inactive phase in both groups. Furthermore, the new substrain showed increased short- and long-term variabilities with lower degree of asymmetry suggesting autonomic dysregulation. Conclusions In summary, the new substrain with schizophrenia-related phenomena showed disturbed motor activity and thermoregulation suggesting that these objectively determined parameters can be biomarkers in translational research.
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Affiliation(s)
- Gyongyi Horvath
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
- * E-mail:
| | - Gabriella Kekesi
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Zita Petrovszki
- Institute of Physical Education and Sport Medicine, Juhász Gyula Faculty of Education, University of Szeged, Szeged, Hungary
| | - Gyorgy Benedek
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Vaanholt LM, Mitchell SE, Sinclair RE, Speakman JR. Mice that are resistant to diet-induced weight loss have greater food anticipatory activity and altered melanocortin-3 receptor (MC3R) and dopamine receptor 2 (D2) gene expression. Horm Behav 2015; 73:83-93. [PMID: 26122292 DOI: 10.1016/j.yhbeh.2015.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/12/2015] [Accepted: 06/13/2015] [Indexed: 11/20/2022]
Abstract
Diet-induced weight loss varies considerably between individuals, but the mechanisms driving these individual differences remain largely unknown. Here we investigated whether key neuropeptides involved in the regulation of energy balance or reward systems were differentially expressed in mice that were prone or resistant to caloric restriction (CR) induced weight loss. Mice (n=30 males and n=34 females) were fed 70% of their own baseline ad libitum intake for 25days, after which their brains were collected and expression of various neuropeptides were investigated and compared between the 10 male and 10 female mice that showed the greatest (high weight loss, HWL) or lowest weight loss (LWL) (n=40 in total). HWL mice showed a differential neuropeptide profile to LWL in both sexes, characterised by increased expression of neuropeptide Y (NPY), agouti-related peptide (AgRP), leptin receptor (ObRb), and melanocortin 3 receptor (MC3R) in the arcuate nucleus. No changes in the expression of fat mass and obesity related gene (FTO) or suppressor of cytokine signalling 3 (Socs3) were observed. Levels of dopamine D2 receptor were decreased in the nucleus accumbens in HWL compared to LWL mice. HWL mice showed a stronger increase in food anticipatory activity (FAA) in response to CR than LWL mice. These results indicate that the mice prone to diet-induced weight loss experienced greater hunger, potentially driving their elevated FAA.
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MESH Headings
- Animals
- Anticipation, Psychological/physiology
- Arcuate Nucleus of Hypothalamus/metabolism
- Caloric Restriction
- Diet, Reducing
- Energy Metabolism/genetics
- Female
- Food
- Gene Expression
- Humans
- Male
- Mice
- Mice, Obese
- Neuropeptide Y/genetics
- Neuropeptide Y/metabolism
- Obesity/diet therapy
- Obesity/genetics
- Obesity/metabolism
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/metabolism
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Receptors, Leptin/genetics
- Receptors, Leptin/metabolism
- Treatment Failure
- Weight Loss/genetics
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Affiliation(s)
- Lobke M Vaanholt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK.
| | - Sharon E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Rachel E Sinclair
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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Vaanholt L, Sinclair R, Mitchell S, Speakman J. Factors influencing individual variability in high fat diet-induced weight gain in out-bred MF1 mice. Physiol Behav 2015; 144:146-55. [DOI: 10.1016/j.physbeh.2015.03.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/13/2015] [Accepted: 03/22/2015] [Indexed: 11/29/2022]
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25
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Stress-induced core temperature changes in pigeons (Columba livia). Physiol Behav 2015; 139:449-58. [DOI: 10.1016/j.physbeh.2014.11.067] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 11/21/2014] [Accepted: 11/25/2014] [Indexed: 11/19/2022]
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26
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Safrany-Fark A, Petrovszki Z, Kekesi G, Keresztes C, Benedek G, Horvath G. Telemetry monitoring for non-invasive assessment of changes in core temperature after spinal drug administration in freely moving rats. J Pharmacol Toxicol Methods 2015; 72:19-25. [PMID: 25595603 DOI: 10.1016/j.vascn.2015.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/08/2014] [Accepted: 01/05/2015] [Indexed: 11/15/2022]
Abstract
INTRODUCTION There are no data available about the effects of spinally administered drugs on thermoregulation in freely moving animals. The first goal of the present study was to throw light on the consequences of intrathecally administered saline as a vehicle on core temperature and motor activity in unrestrained conditions. The second goal was to characterize the effects of morphine on these parameters as a widely used antinociceptive drug in spinal anesthesia, and reveal the potential role of the N-methyl-d-aspartate (NMDA) receptors in these processes. METHODS For these purposes, male Wistar rats were catheterized intrathecally, and E-Mitter battery-free transponders were implanted intraabdominally to continuously monitor core temperature and locomotor activity. RESULTS Saline induced a short-lasting hyperactivity accompanied by significant and prolonged hyperthermia that was blunted by systemic paracetamol administration. Morphine had no impact on motor activity; however, it caused high but equivalent degree hyperthermia in a wide dose range (1-15 μg), suggesting that it reached its peak effect. In the highest applied dose (25 μg), the NMDA receptor antagonist kynurenic acid blunted the saline-induced hyperthermia, and all doses caused higher hyperactivity compared to vehicle or morphine injections. In combination, kynurenic acid significantly inhibited the morphine-induced hyperthermia. DISCUSSION These data suggest that this method might be a valuable tool for investigating the thermoregulatory and locomotor effects of different drugs at spinal level; however, the prolonged effects of intrathecal vehicle injections should also be considered. The results point out that morphine is a very potent hyperthermic drug that may act primarily on the efferent limb of thermoregulation, at least partially, via an indirect NMDA-receptor mediated action mechanism.
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Affiliation(s)
- A Safrany-Fark
- Department of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, University of Szeged, Tisza L. krt. 64, H-6720 Szeged, Hungary.
| | - Z Petrovszki
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary.
| | - G Kekesi
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary.
| | - C Keresztes
- Department of Medical Communication and Translation, Faculty of Medicine, University of Szeged, Szentháromság u. 5, H-6720 Szeged, Hungary.
| | - G Benedek
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary.
| | - G Horvath
- Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary.
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Ramos-Lobo AM, Buonfiglio DC, Cipolla-Neto J. Streptozotocin-induced diabetes disrupts the body temperature daily rhythm in rats. Diabetol Metab Syndr 2015; 7:39. [PMID: 25960780 PMCID: PMC4424512 DOI: 10.1186/s13098-015-0035-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/16/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND In mammals, the temperature rhythm is regulated by the circadian pacemaker located in the suprachiasmatic nuclei, and is considered a "marker rhythm". Melatonin, the pineal gland hormone, is a major regulator of the endogenous rhythms including body temperature. Its production is influenced by many factors, such as type 1 diabetes mellitus. In rats, diabetes leads to hypothermia and reduced melatonin synthesis; insulin treatment reestablishes both. AIM To study the body temperature daily rhythm of diabetic animals and the effects of insulin and/or melatonin treatment on its structure. METHODS We studied the effects of streptozotocin-induced diabetes (60 mg/kg) on the body temperature rhythm of Wistar rats and the possible modifications resulting from early and late treatments with insulin (6U/day) and/or melatonin (daily 0.5 mg/kg). We monitored the daily body temperature rhythm, its rhythmic parameters (MESOR, amplitude and acrophase), glycemia and body weight for 55 days. Data were classified by groups and expressed as mean ± SEM. One-way ANOVA analysis was performed followed by Bonferroni posttest. Statistical significance was set at p < 0.05. RESULTS Diabetes led to complete disruption of the temperature rhythm and hypothermia, which were accentuated over time. All early treatments (insulin or/and melatonin) prevented the temperature rhythm disruption and hypothermia. Insulin plus melatonin restored the body temperature rhythm whereas insulin alone resulted less efficient; melatonin alone did not restore any of the parameters studied; however, when supplemented close to diabetes onset, it maintained the temperature rhythmicity. All these corrective effects of the early treatments were dependent on the continuous maintenance of the treatment. CONCLUSIONS Taken together, our findings show the disruption of the body temperature daily rhythm, a new consequence of insulin-dependent diabetes, as well as the beneficial effect of the complementary action of melatonin and insulin restoring the normal rhythmicity.
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Affiliation(s)
- Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Lineu Prestes, 1524, São Paulo, SP 05508-000 Brazil
| | - Daniella C Buonfiglio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Lineu Prestes, 1524, São Paulo, SP 05508-000 Brazil
| | - José Cipolla-Neto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Lineu Prestes, 1524, São Paulo, SP 05508-000 Brazil
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Characterisation of the antidepressant properties of nitric oxide synthase inhibitors in the olfactory bulbectomised rat model of depression. Eur Neuropsychopharmacol 2014; 24:1349-61. [PMID: 24931298 DOI: 10.1016/j.euroneuro.2014.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 04/11/2014] [Accepted: 05/09/2014] [Indexed: 02/05/2023]
Abstract
Nitric oxide synthase (NOS) inhibitors possess antidepressant-like properties in preclinical tests and in the current investigation the brain penetrant NOS inhibitor N(ω)-nitro-L-arginine (l-NA) and the preferential inhibitor of neuronal NOS (nNOS) 1-(2-trifluoromethylphenyl) imidazole (TRIM) were assessed in the olfactory bulbectomised (OB) rat, a well-established animal model of depression. Magnetic resonance imaging (MRI) was employed to assess regional brain volumes, blood perfusion and T1 and T2 relaxometry times both with and without drug treatment. l-NA (10 mg/kg, once daily p.o. for 10 days) attenuated OB-related hyperactivity in the "open field" test in a comparable fashion to the tricyclic antidepressant imipramine (20 mg/kg, once daily p.o. for 14 days) indicative of an antidepressant-like response in the model. Treatment with TRIM (50 mg/kg, once daily s.c.) attenuated OB-related hyperactivity following 7 days of treatment when compared to vehicle treated controls. OB is associated with enlarged ventricular volume, increased periventicular perfusion and a decrease in T2 relaxation times in cortical and hippocampal regions, with enhanced perfusion and reduced T2 times attenuated by L-NA treatment. L-NA treatment was also associated with an increase in T1 relaxation times in limbic and cortical regions and found to reduce resting state hippocampal blood perfusion in OB animals. Behavioural observations are consistent with an antidepressant action of NOS inhibitors where associated changes in perfusion and T2 relaxation times may be related to the antidepressant action of L-NA in the model.
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Pétervári E, Rostás I, Soós S, Tenk J, Mikó A, Füredi N, Székely M, Balaskó M. Age versus nutritional state in the development of central leptin resistance. Peptides 2014; 56:59-67. [PMID: 24680735 DOI: 10.1016/j.peptides.2014.03.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 03/05/2014] [Accepted: 03/09/2014] [Indexed: 02/06/2023]
Abstract
Leptin, a catabolic adiposity signal acts in the hypothalamus via suppressing food intake and inducing hypermetabolism. Age and obesity are accompanied by leptin resistance. The present study aimed to clarify which components of the catabolic leptin effects are influenced most strongly by aging and which ones by nutritional state-induced alterations in body composition. In our biotelemetric study the effects of a 7-day intracerebroventricular leptin infusion on various parameters of energy balance (food intake, body weight, oxygen consumption, heart rate and body temperature) were analyzed in male Wistar rats of different age-groups (from 3 to 24 months) and nutritional states (normally fed, diet-induced obese and calorie-restricted). Leptin resistance of older animals affected hypermetabolic actions, whereas leptin induced anorexia in all age-groups. Weight reducing effect of leptin diminished in middle-aged and aging animals to become significant again in the oldest group. In diet-induced obese rats leptin-induced hypermetabolism of the young rats and hypermetabolism plus anorexia of the aging ones were suppressed. Calorie-restriction reduced body weight and fat mass to a similar extent in all age-groups. It strongly enhanced leptin-induced hypermetabolism at all ages and prevented the manifestation of anorexigenic actions of leptin with the exception of the oldest group. This latter finding suggests an unexpected increase of responsiveness to anorexigenic leptin actions in old rats. Accordingly, anorexia and hypermetabolism change in disparate ways with aging. Nutritional state predominantly influences hypermetabolic leptin actions. Resistance to both hypermetabolic and anorexigenic actions were promoted by obesity, while calorie-restriction enhanced responsiveness to leptin, especially in old rats.
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Affiliation(s)
- Erika Pétervári
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
| | - Ildikó Rostás
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
| | - Szilvia Soós
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
| | - Judit Tenk
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
| | - Alexandra Mikó
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
| | - Nóra Füredi
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
| | - Miklós Székely
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary.
| | - Márta Balaskó
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary, 12. Szigeti str., H-7624 Pécs, Hungary
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Chapon PA, Bulla J, Gauthier A, Moussay S. On the importance of telemetric temperature sensor location during intraperitoneal implantation in rats. Lab Anim 2014; 48:114-23. [PMID: 24585934 DOI: 10.1177/0023677214522035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study aims to assess the thermal homogeneity of the intraperitoneal (IP) cavity and the relevance of using a fixed telemetric temperature sensor at a given location in studying rodents. Ten rats were intraperitoneally implanted with three Jonah® capsules each; after assessing the accuracy and reliability of the sensors. Two capsules were attached, one to the right iliac fossa (RIF) and the other to the left hypochondrium (LH), and another was placed between the intestines but not attached (Free). In the ex vivo condition, the differences between sensors and reference values remained in the range of ±0.1. In the in vivo condition, each sensor enabled the observation of temperature patterns. However, sensor location affected mean and median temperature values while the rats were moving freely. Indeed, temperature data collected in the LH were 0.1 significantly higher than those collected in the RIF and temperature data collected in the LH were 0.11 significantly higher than those collected with the Free capsules. In in vivo conditions, intra-sensor variability of temperature data was not affected by sensor location. Taking into account sensor accuracy, similar intra-sensor variability, and mean differences observed between the three locations, the impact of sensor location within the IP cavity could be considered negligible. In in vivo conditions, temperature differences between locations regularly exceeded ±0.2 and reached up to 2.5. These extreme values could be explained by behavioral factors such as food or water intake. Finally, considering the good thermal homogeneity of the IP cavity and possible adverse consequences of sensor attachment, it seems better to let sensors range free within the cavity.
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31
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Vaanholt LM, Magee V, Speakman JR. Factors predicting individual variability in diet-induced weight loss in MF1 mice. Obesity (Silver Spring) 2012; 20:285-94. [PMID: 21996667 DOI: 10.1038/oby.2011.279] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The effectiveness of caloric restriction (CR) as a treatment for obesity varies considerably between individuals. Reasons for this interindividual variation in weight loss in response to CR may lie in pre-existing individual differences and/or individual differences in compensatory responses. Here we studied the responses of 127 MF1 mice to 30% CR over four weeks, and investigated whether pre-existing differences or compensatory changes in body temperature, resting metabolic rate (RMR) and behavior explained the variation observed in body mass (BM) and fat mass (FM) changes. Mice showed considerable variation in BM loss (36-1%), and in the type of tissue lost (FM or fat free mass, FFM). About 50% of the variation in BM and FM loss could be predicted by pre-existing differences in food intake, RMR, and general activity, where BM loss was greater when food intake was lower and activity and RMR were higher. Compensatory changes in activity and body temperature together explained ~50% of the variation in BM and FM loss in both sexes. In models incorporating baseline variables and compensatory changes, food intake, and activity were the strongest predictors of weight loss in both sexes; i.e., lower baseline food intake and increased changes in activity resulted in greater BM and FM loss. Interestingly, increased baseline activity was a significant predictor of weight loss independent of compensatory changes in activity. Identifying factors involved in individual variability in weight loss may give insights into the mechanisms that underlie this variability, and is important to develop individually tailored weight-management strategies.
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Affiliation(s)
- Lobke M Vaanholt
- Integrative Physiology, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
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Leptin action in the dorsomedial hypothalamus increases sympathetic tone to brown adipose tissue in spite of systemic leptin resistance. J Neurosci 2011; 31:12189-97. [PMID: 21865462 DOI: 10.1523/jneurosci.2336-11.2011] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Leptin regulates body weight in mice by decreasing appetite and increasing sympathetic nerve activity (SNA), which increases energy expenditure in interscapular brown adipose tissue (iBAT). Diet-induced obese mice (DIO) are resistant to the anorectic actions of leptin. We evaluated whether leptin still stimulated sympathetic outflow in DIO mice. We measured iBAT temperature as a marker of SNA. We found that obese hyperleptinemic mice have higher iBAT temperature than mice on regular diet. Conversely, obese leptin-deficient ob/ob mice have lower iBAT temperature. Additionally, leptin increased SNA in obese (DIO and ob/ob) and control mice, despite DIO mice being resistant to anorectic action of leptin. We demonstrated that neurons in the dorsomedial hypothalamus (DMH) of DIO mice mediate the thermogenic responses to hyperleptinemia in obese mammals because blockade of leptin receptors in the DMH prevented the thermogenic effects of leptin. Peripheral Melotan II (MTII) injection increased iBAT temperature, but it was blunted by blockade of DMH melanocortin receptors (MC4Rs) by injecting agouti-related peptide (AgRP) directly into the DMH, suggesting a physiological role of the DMH on temperature regulation in animals with normal body weight. Nevertheless, obese mice without a functional melanocortin system (MC4R KO mice) have an increased sympathetic outflow to iBAT compared with their littermates, suggesting that higher leptin levels drive sympathoexcitation to iBAT by a melanocortin-independent pathway. Because the sympathetic nervous system contributes in regulating blood pressure, heart rate, and hepatic glucose production, selective leptin resistance may be a crucial mechanism linking adiposity and metabolic syndrome.
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Establishment of the black-tailed prairie dog (Cynomys ludovicianus) as a novel animal model for comparing smallpox vaccines administered preexposure in both high- and low-dose monkeypox virus challenges. J Virol 2011; 85:7683-98. [PMID: 21632764 DOI: 10.1128/jvi.02174-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 2003 monkeypox virus (MPXV) outbreak and subsequent laboratory studies demonstrated that the black-tailed prairie dog is susceptible to MPXV infection and that the ensuing rash illness is similar to human systemic orthopoxvirus (OPXV) infection, including a 7- to 9-day incubation period and, likely, in some cases a respiratory route of infection; these features distinguish this model from others. The need for safe and efficacious vaccines for OPVX in areas where it is endemic or epidemic is important to protect an increasingly OPXV-naïve population. In this study, we tested current and investigational smallpox vaccines for safety, induction of anti-OPXV antibodies, and protection against mortality and morbidity in two MPXV challenges. None of the smallpox vaccines caused illness in this model, and all vaccinated animals showed anti-OPXV antibody responses and neutralizing antibody. We tested vaccine efficacy by challenging the animals with 10(5) or 10(6) PFU Congo Basin MPXV 30 days postvaccination and evaluating morbidity and mortality. Our results demonstrated that vaccination with either Dryvax or Acambis2000 protected the animals from death with no rash illness. Vaccination with IMVAMUNE also protected the animals from death, albeit with (modified) rash illness. Based on the results of this study, we believe prairie dogs offer a novel and potentially useful small animal model for the safety and efficacy testing of smallpox vaccines in pre- and postexposure vaccine testing, which is important for public health planning.
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Richard CD, Tolle V, Low MJ. Meal pattern analysis in neural-specific proopiomelanocortin-deficient mice. Eur J Pharmacol 2011; 660:131-8. [PMID: 21211523 DOI: 10.1016/j.ejphar.2010.12.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 12/10/2010] [Accepted: 12/11/2010] [Indexed: 10/18/2022]
Abstract
The central melanocortin system, consisting of melanocortin peptides, agouti gene related peptide and their receptors plays a critical role in the homeostatic control of energy balance. Loss of function mutations in the genes encoding proopiomelanocortin or melanocortin MC(4) receptors cause profound obesity and hyperphagia. However, little is known about the functional relationship of melanocortin neurocircuits to the temporal organization of meal-taking behavior. We used an operant paradigm that combined lever pressing for food pellet deliveries with free water intake monitored by lickometers to quantify meal patterns in mutant mice that selectively lack proopiomelanocortin expression in hypothalamic neurons (nPOMCKO). Compared to wildtype siblings, nPOMCKO mice consumed 50% more food and water daily and exhibited a more stereotyped feeding pattern characterized by reduced inter-meal and inter-mouse variations. Average meals were larger in size but shorter in duration, with no change in meal number. Consequently, intermeal intervals were prolonged in nPOMCKO mice. Similar patterns were observed in pre-obese juvenile and frankly obese adult mice suggesting that neither age nor degree of obesity was responsible for the altered phenotypes. Spontaneous locomotion and wheel running were decreased in nPOMCKO mice, but circadian variations in locomotor and feeding activity were conserved. These data show that hyperphagia in male nPOMCKO mice is due to increased meal size but not meal number, and this pattern is established by age of 5weeks. The combination of larger, more rapidly consumed meals and prolonged intermeal intervals suggests that proopiomelanocortin peptides are necessary for normal meal termination, but not the maintenance of satiety.
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Affiliation(s)
- Christian D Richard
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, United States
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Soos S, Petervari E, Szekely M, Jech-Mihalffy A, Balasko M. Complex catabolic effects of central alpha-MSH infusion in rats of altered nutritional states: differences from leptin. J Mol Neurosci 2010; 43:209-16. [PMID: 20953734 DOI: 10.1007/s12031-010-9462-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 10/05/2010] [Indexed: 01/15/2023]
Abstract
The hypothalamic melanocortin (MC) system is a major catabolic regulator of energy balance: it suppresses food intake (FI), elevates metabolic rate, and reduces body weight (BW). The primary activator of the MC system [mainly via the alpha-melanocyte stimulating hormone (alpha-MSH)] is the adipocyte-derived leptin. With increasing BW, resistance develops to leptin-induced anorexia, but independent of this, in genetically modified animals, some alpha-MSH actions were maintained. We investigated the responsiveness of the MC system in its complexity (FI vs. metabolic correlates) in genetically intact male Wistar rats of different nutritional states (and different leptin sensitivities), i.e., in rats aged 2 months [normally fed (NF2)] or 6 months [calorie-restricted (CR6), fed ad libitum (NF6), and high-fat diet-induced obese (HF6) groups]. A 7-day-long, 1-μg/μl/h intracerebroventricular infusion of alpha-MSH reduced BW in all groups, particularly in NF6 and NF2 animals, and even CR6 rats lost BW upon alpha-MSH infusion (in contrast to leptin administration). Anorexia developed in NF2-NF6 and less in CR6 groups, and some FI fall was also seen in HF6 rats. The hypermetabolic effects (temperature/heart rate elevations) were most pronounced in CR6 and next in HF6 rats. These data suggest that alpha-MSH responsiveness is maintained in various forms (depending on nutritional state), despite obesity-induced leptin resistance.
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Affiliation(s)
- Szilvia Soos
- Department of Pathophysiology and Gerontology, Medical School, University of Pecs, 12 Szigeti ut, Pecs H-7624, Hungary
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Vanattou-Saïfoudine N, McNamara R, Harkin A. Caffeine promotes dopamine D1 receptor-mediated body temperature, heart rate and behavioural responses to MDMA ('ecstasy'). Psychopharmacology (Berl) 2010; 211:15-25. [PMID: 20437223 DOI: 10.1007/s00213-010-1864-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 04/08/2010] [Indexed: 12/17/2022]
Abstract
RATIONALE Caffeine exacerbates the acute toxicity of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') in rats characterised by hyperthermia, tachycardia and lethality. Depletion of central catecholamine stores and dopamine D(1) receptor blockade have been reported to attenuate the ability of caffeine to exacerbate MDMA-induced hyperthermia. OBJECTIVES Here, we investigate whether dopamine D(1) and D(2) receptors mediate the effects of caffeine on MDMA-induced changes in body temperature, heart rate and locomotor activity. METHODS All parameters were recorded continuously in individually housed rats using bioradiotelemetry from 1 h prior to 4 h following caffeine (10 mg/kg, s.c.) and/or MDMA (10 mg/kg, s.c.) administration. RESULTS Co-administration of caffeine with MDMA provoked a switch from MDMA-induced hypothermia and bradycardia to hyperthermia and tachycardia without influencing MDMA-induced hyperlocomotion. Pre-treatment with a specific dopamine D(1/5) antagonist SCH 23390 (1 mg/kg) enhanced MDMA-induced hypothermia and blocked the ability of caffeine to provoke a switch from MDMA-induced hypothermia to hyperthermia. Furthermore, SCH 23390 blocked MDMA-induced hyperactivity and the ability of caffeine to promote a tachycardic response to MDMA. By contrast, pre-treatment with the selective D(2) antagonist, sulpiride (100 mg/kg) blocked MDMA-induced hypothermia, failed to influence the ability of caffeine to promote tachycardia whilst enhancing MDMA-induced hyperactivity. CONCLUSIONS Our results highlight the importance of dopamine D(1) and D(2) receptors in shaping the behavioural and physiological response to MDMA and suggest that the ability of caffeine to provoke MDMA-induced toxicity is associated with the promotion of dopamine D(1) over D(2) receptor-related responses.
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Affiliation(s)
- Natacha Vanattou-Saïfoudine
- Neuropsychopharmacology Research Group, Trinity College Institute of Neuroscience, Trinity College of Dublin, Dublin, 2, Ireland
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Duarte LC, Vaanholt LM, Sinclair RE, Gamo Y, Speakman JR. Limits to sustained energy intake XII: is the poor relation between resting metabolic rate and reproductive performance because resting metabolism is not a repeatable trait? ACTA ACUST UNITED AC 2010; 213:278-87. [PMID: 20038662 DOI: 10.1242/jeb.037069] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many studies have investigated the consequences of individual variation in resting metabolic rate at thermoneutrality (RMRt) on reproductive performance. Despite strong theoretical reasons for expecting such an association, results have generally been disappointing. A fundamental assumption of these studies is that RMRt is a repeatable trait. We examined repeatability of RMRt in female MF1 mice over short (15 days apart; N=238) and long intervals (110 days apart; N=33). In the long-term experiment, after the first RMRt measurement, females were separated in two groups: the first was kept virgin (N=16); the second was allowed to breed (N=17) and measured 15 days after they had weaned their pups. We also examined the association between RMRt and reproduction. We used Pearson's correlation (r) and intraclass correlation coefficients (rho) to estimate repeatability. There was a strong effect of body mass on RMRt for all measurements. Over the short interval, repeatability was significant for body mass (r=0.86; rho=0.86), RMRt (r=0.68; rho=0.68,) and residual-RMRt (r=0.58; rho=0.58). Over long intervals, repeatability of residual-RMRt was high in virgin females (r=0.59; rho=0.60), but not in the breeders (r=0.38; rho=0.39); body mass was repeatable only for non-breeders measured by r (r=0.55). There was no significant correlation between RMRt or residual-RMRt and litter size or litter mass. In conclusion, RMRt and residual-RMRt are highly repeatable traits in virgin MF1 female mice. The lack of association between non-reproductive RMRt and reproductive performance in MF1 mice does not come about because of its poor repeatability.
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Affiliation(s)
- L C Duarte
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
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Posner LP, Pavuk AA, Rokshar JL, Carter JE, Levine JF. Effects of opioids and anesthetic drugs on body temperature in cats. Vet Anaesth Analg 2010; 37:35-43. [DOI: 10.1111/j.1467-2995.2009.00508.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Anorexic vs. metabolic effects of central leptin infusion in rats of various ages and nutritional states. J Mol Neurosci 2009; 41:97-104. [PMID: 19777381 DOI: 10.1007/s12031-009-9294-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Accepted: 09/09/2009] [Indexed: 12/21/2022]
Abstract
Age-related obesity is known to be adjoined by leptin resistance. It has not been clarified whether the resistance is cause or result of obesity. In the present experiments, the anorexic (suppressing food intake and body weight) and hypermetabolic (increasing body temperature (Tc), activity, and heart rate (HR), indicating metabolic rate) responses to 7-day-long intracerebroventricular leptin infusion were compared in 2- and 6-month-old normally fed (NF2 and NF6 groups), 6-month-old high-fat-diet-induced obese (HF6), and 6-month-old calorie-restricted (CR6) rats. The anorexic effects were inversely related to fat content: They were most pronounced in NF2, less in NF6, non-significant in HF6 rats, but also absent in CR6 animals of the lowest fat content. This virtual leptin resistance in CR6 rats was due to their high orexigenic activity (enhanced feeding response to NPY). In contrast, CR6 rats were hypersensitive to the metabolic effects of leptin infusion (rise in Tc and HR; biotelemetric measurements), NF2 were still sensitive, while NF6 and HF6 rats exhibited moderate or low sensitivity. In conclusion, leptin resistance depends on body fat content rather than on age itself, although with age the proportion of fat tissue increases and contributes to self-perpetuating rise in body weight.
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Cope MB, Li X, Jumbo-Lucioni P, DiCostanzo CA, Jamison WG, Kesterson RA, Allison DB, Nagy TR. Risperidone alters food intake, core body temperature, and locomotor activity in mice. Physiol Behav 2008; 96:457-63. [PMID: 19084548 DOI: 10.1016/j.physbeh.2008.11.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 11/06/2008] [Accepted: 11/21/2008] [Indexed: 11/17/2022]
Abstract
Risperidone induces significant weight gain in female mice; however, the underlying mechanisms related to this effect are unknown. We investigated the effects of risperidone on locomotor activity, core body temperature, and uncoupling protein (UCP) and hypothalamic orexin mRNA expression. Female C57BL/6J mice were acclimated to individual housing and randomly assigned to either risperidone (4 mg/kg BW day) or placebo (PLA). Activity and body temperature were measured over 48-hour periods twice a week for 3 weeks. Food intake and body weights were measured weekly. UCP1 (BAT), UCP3 (gastrocnemius), and orexin (hypothalamus) mRNA expressions were measured using RT-PCR. Risperidone-treated mice consumed more food (p=0.050) and gained more weight (p=0.0001) than PLA-treated mice after 3 weeks. During the initial 2 days of treatment, there was an acute effect of treatment on activity (p=0.046), but not body temperature (p=0.290). During 3 weeks of treatment, average core body temperatures were higher in risperidone-treated mice compared to controls during the light phase (p=0.0001), and tended to be higher during the dark phase (p=0.057). Risperidone-treated mice exhibited lower activity levels than controls during the dark phase (p=0.006); there were no differences in activity during the light phase (p=0.47). UCP1 (p<0.01) and UCP3 (p<0.05) mRNA expressions were greater in risperidone-treated mice compared to controls, whereas, orexin mRNA expression was lower in risperidone-treated mice (p<0.01). These results suggest that risperidone-induced weight gain in mice is a consequence of increased energy intake and reduced activity, while the elevation in body temperature may be a result of thermogenic effect of food intake and elevated UCP1, UCP3, and a reduced hypothalamic orexin expression.
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Affiliation(s)
- Mark B Cope
- Department of Nutrition Sciences, University of Alabama at Birmingham, United States
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Billes SK, Cowley MA. Catecholamine reuptake inhibition causes weight loss by increasing locomotor activity and thermogenesis. Neuropsychopharmacology 2008; 33:1287-97. [PMID: 17687262 DOI: 10.1038/sj.npp.1301526] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Bupropion (BUP) is a dopamine (DA) and norepinephrine (NE) reuptake inhibitor that causes mild weight loss in obese adults. Subchronic (7 day) coadministration of selective DA and NE reuptake inhibitors also causes weight loss in mice. Because weight loss was not associated with decreased caloric intake, subchronic BUP might cause weight loss through increased energy expenditure. Acute studies demonstrate that BUP or DA+NE reuptake inhibitors cause transient hypophagia and increased locomotion; though the effects on temperature are inconsistent. Because subchronic DA+NE reuptake inhibition does not affect appetite, there is clearly a difference between the acute and subchronic effects of DA+NE reuptake inhibitors; however the effects of chronic (or subchronic) BUP on energy balance have never been directly studied in an animal model. Therefore, the acute and subchronic effects of BUP or selective DA and NE reuptake inhibitors on food intake, body weight, locomotor activity, and interscapular temperature were determined in mice. Generally, selective inhibition of DA reuptake (by GBR12783) increased activity while selective inhibition of NE reuptake (by nisoxetine, NIS) decreased activity and temperature. BUP increased activity and temperature but subchronic BUP did not significantly reduce body weight due to a compensatory increase in food intake. Subchronic DA+NE reuptake inhibitor coadministration mimicked the effect of BUP on activity and temperature, but caused weight loss because daily food intake was not increased. The results of this study suggest that the mild weight loss effect of BUP in humans may be due to increased locomotion or heat production. More importantly, inhibition of DA+NE reuptake (with GBR+NIS) increased energy expenditure without a compensatory increase in food intake, supporting a role for novel combination catecholamine reuptake inhibitors in pharmacotherapy for obesity.
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Affiliation(s)
- Sonja K Billes
- Division of Neuroscience, Oregon National Primate Research Center/Oregon Health and Science University, Beaverton, OR 97006, USA
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Authier S, Tanguay JF, Gauvin D, Di Fruscia R, Fournier S, Chaurand F, Troncy E. A cardiovascular monitoring system in conscious cynomolgus monkeys for regulatory safety pharmacology. J Pharmacol Toxicol Methods 2007; 56:115-21. [PMID: 17587601 DOI: 10.1016/j.vascn.2007.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 03/30/2007] [Indexed: 11/24/2022]
Abstract
INTRODUCTION This project addresses the validation study design of a test system using a telemetered non-human primate model for cardiovascular safety pharmacology evaluation. METHODS The validation provided by the supplier evaluated installation (IQ) and operation (OQ) qualifications. This protocol was completed with tests evaluating electronic data management and accuracy and precision of transmitter (n=4) measurements for temperature and pressure criteria with a series of tested values. As part of performance qualification, physical activity (for 24 h) as well as cardiovascular, ECG (20 complexes for each animal) and systemic arterial blood pressure (SAP, 10 different measures), data were recorded simultaneously from the same animals (n=4) using certified equipment and the telemetry system. Reliability was evaluated over 60 days. RESULTS The IQ and OQ were completed successfully. The electronic data management was performed successfully. The ex-vivo evaluation for temperature and pressure showed high correlation (R(2)>0.99) but with a slight pressure shift, as expected, with this transmitter model. For physical activity, the correlation coefficients were good to excellent with high activity counts but the comparison demonstrated a limited sensitivity of the telemetry system with animal presenting low activity levels. ECG interval measurement using the telemetry software was considered at least equivalent to manual measurement, but with some limitations in the reading of the ECG. The comparison between both methods of SAP measurement showed adequate precision (R(2)=0.969) but no accuracy. DISCUSSION Reference monitoring methods are important to ensure proper test system validation. Monitoring with a reference methodology and the telemetry system is important in order to evaluate precision and accuracy of the test system. Computerized analysis may lack the capability to analyze ECG complexes with abnormal morphologies. This reinforces the need to have ECG evaluation prior to telemetry implantation along with visual evaluation of ECG tracing at standard speed (e.g. 50 mm/s) at all time points.
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Affiliation(s)
- Simon Authier
- LAB Research Inc., 445 Armand Frappier, Laval, Quebec, Canada.
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Roche M, Harkin A, Kelly JP. Chronic fluoxetine treatment attenuates stressor-induced changes in temperature, heart rate, and neuronal activation in the olfactory bulbectomized rat. Neuropsychopharmacology 2007; 32:1312-20. [PMID: 17119540 DOI: 10.1038/sj.npp.1301253] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The olfactory bulbectomized (OB) rat is a well-characterized animal model that exhibits a number of behavioral and neurochemical changes that have relevance to clinical depression. Hyperactivity in the open field is the most widely used parameter assessed in this model and is reversed following chronic, but not acute, antidepressant treatment. This study investigated OB-induced alterations in heart rate, body temperature, and neuronal activation following open-field exposure and the impact of chronic treatment with fluoxetine on these parameters. Upon placement in the open field, OB rats exhibited a characteristic hyperactivity response. Heart rate and body temperature were increased in sham-operated rats following open-field exposure, a predictable response to stress, which was significantly reduced in OB rats. Moreover bulbectomy reduced open field-induced cFOS expression in the basal nucleus of the stria terminalis while concurrently increasing expression in the hippocampus, amygdala, paraventricular nucleus of the thalamus, and dorsal raphe nucleus. Chronic fluoxetine treatment (10 mg/kg subcutaneous once daily for 5 weeks) attenuated all of these OB-associated changes. In conclusion, OB rats exhibit alterations in behavior, body temperature, heart rate, and neuronal activation in response to open-field exposure, which are reversed following chronic fluoxetine administration. These results identify stress-sensitive regions within the brain which are altered following bulbectomy and which may underlie the abnormal behavioral and physiological changes observed in this rodent model of depression.
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Affiliation(s)
- Michelle Roche
- Department of Pharmacology, National University of Ireland, Galway, Galway, Ireland.
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McNamara R, Maginn M, Harkin A. Caffeine induces a profound and persistent tachycardia in response to MDMA (“Ecstasy”) administration. Eur J Pharmacol 2007; 555:194-8. [PMID: 17126829 DOI: 10.1016/j.ejphar.2006.10.063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 10/24/2006] [Accepted: 10/30/2006] [Indexed: 11/25/2022]
Abstract
Caffeine promotes hyperthermia and lethality when co-administered with the recreational drug 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") to rats. In the present study, co-administration of caffeine (10 mg/kg, s.c.) with MDMA (10 mg/kg, s.c.) induced a profound tachycardic response compared to rats treated with either drug alone. However, neither caffeine (30 microM) nor MDMA (1-30 microM), alone or in combination, affected the electrocardiogram of the isolated heart suggesting that central and sympathomimetic actions, rather than direct actions of these drugs on the heart, are responsible for the tachycardia observed in vivo. This is a serious drug interaction, which could have important health consequences for recreational drug users.
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Affiliation(s)
- Ruth McNamara
- Department of Pharmacology, National University of Ireland, Galway, Ireland
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McNamara R, Kerans A, O'Neill B, Harkin A. Caffeine promotes hyperthermia and serotonergic loss following co-administration of the substituted amphetamines, MDMA (“Ecstasy”) and MDA (“Love”). Neuropharmacology 2006; 50:69-80. [PMID: 16188283 DOI: 10.1016/j.neuropharm.2005.08.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 08/10/2005] [Accepted: 08/11/2005] [Indexed: 10/25/2022]
Abstract
The present study determined the effect of caffeine co-administration on the core body temperature response and long-term serotonin (5-HT) loss induced by methylenedioxymethamphetamine (MDMA; "Ecstasy") and its metabolite methylenedioxyamphetamine (MDA; "Love") to rats. In group-housed animals, caffeine (10 mg/kg) enhanced the acute toxicity of MDMA (15 mg/kg) and MDA (7.5 mg/kg), resulting in an exaggerated hyperthermic response (+2 degrees C for 5 h following MDMA and +1.5 degrees C for 3 h following MDA) when compared to MDMA (+1 degree C for 3 h) and MDA (+1 degree C for 1 h) alone. Co-administration of caffeine with MDMA or MDA was also associated with increased lethality. To reduce the risk of lethality, doses of MDMA and MDA were reduced in further experiments and the animals were housed individually. To examine the effects of repeated administration, animals received MDMA (10 mg/kg) or MDA (5 mg/kg) with or without caffeine (10 mg/kg) twice daily for 4 consecutive days. MDMA and MDA alone induced hypothermia (fall of 1 to 2 degrees C) over the 4 treatment days. Co-administration of caffeine with MDMA or MDA resulted in hyperthermia (increase of up to 2.5 degrees C) following acute administration compared to animals treated with caffeine or MDMA/MDA alone. This hyperthermic response to caffeine and MDMA was not observed with repeated administration, unlike caffeine + MDA, where hyperthermia was obtained over the 4 day treatment period. In addition, 4 weeks after the last treatment, co-administration of caffeine with MDA (but not MDMA) induced a reduction in 5-HT and 5-hydroxyindole acetic acid (5-HIAA) concentrations in frontal cortex (to 61% and 58% of control, respectively), hippocampus (48% and 60%), striatum (79% and 64%) and amygdala (63% and 37%). However, when caffeine (10 mg/kg) and MDMA (2.5 mg/kg) were co-administered four times daily for 2 days to group-housed animals, both hyperthermia and hippocampal 5-HT loss were observed (reduced to 68% of control). Neither MDMA nor MDA alone induced a significant reduction in regional 5-HT or 5-HIAA concentrations following repeated administration. In conclusion, caffeine promotes the acute and long-term toxicity associated with MDMA and MDA. This is a serious drug interaction, which could have important acute and long-term health consequences for recreational drug users.
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Affiliation(s)
- Ruth McNamara
- Department of Pharmacology, National University of Ireland, Galway
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46
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Mortola JP, Lanthier C. Scaling the amplitudes of the circadian pattern of resting oxygen consumption, body temperature and heart rate in mammals. Comp Biochem Physiol A Mol Integr Physiol 2004; 139:83-95. [PMID: 15471685 DOI: 10.1016/j.cbpb.2004.07.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 07/01/2004] [Accepted: 07/12/2004] [Indexed: 11/25/2022]
Abstract
We questioned whether the amplitudes of the circadian pattern of body temperature (T(b)), oxygen consumption (V (O(2))) and heart rate (HR) changed systematically among species of different body weight (W). Because bodies of large mass have a greater heat capacitance than those of smaller mass, if the relative amplitude (i.e., amplitude/mean value) of metabolic rate was constant, one would expect the T(b) oscillation to decrease with the increase in the species W. We compiled data of T(b), V (O(2)) and HR from a literature survey of over 200 studies that investigated the circadian pattern of these parameters. Monotremata, Marsupials and Chiroptera, were excluded because of their characteristically low metabolic rate and T(b). The peak-trough ratios of V (O(2)) (42 species) and HR (35 species) averaged, respectively, 1.57+/-0.08, and 1.35+/-0.07, and were independent of W. The daily high values of T(b) did not change, while the daily low T(b) values slightly increased, with the species W; hence, the high-low T(b) difference (57 species) decreased with W (3.3 degrees C.W(-0.13)). However, the decrease in T(b) amplitude with W was much less than expected from physical principles, and the high-low T(b) ratio remained significantly above unity even in the largest mammals. Thus, it appears that in mammals, despite the huge differences in physical characteristics, the amplitude of the circadian pattern is a fixed (for V (O(2)) and HR), or almost fixed (for T(b)), fraction of the 24-h mean value. Presumably, the amplitudes of the oscillations are controlled parameters of physiological significance.
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Affiliation(s)
- Jacopo P Mortola
- Department of Physiology, McGill University, 3655, Sir William Osler Promenade Montreal, Quebec, Canada, H3G 1Y6.
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47
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Degen SB, Verheij MMM, Cools AR. Genetic background, nature of event, and time of exposure to event direct the phenotypic expression of a particular genotype. Behav Brain Res 2004; 154:107-12. [PMID: 15302116 DOI: 10.1016/j.bbr.2004.01.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Revised: 01/28/2004] [Accepted: 01/29/2004] [Indexed: 11/24/2022]
Abstract
The aim of this study was to investigate the differential long-term after-effects on the apomorphine-susceptibility in the apomorphine-susceptible (APO-SUS) and apomorphine-unsusceptible (APO-UNSUS) rats of either a saline injection (a mild stressor) or a clonidine-injection (a moderate stressor) applied around the onset of the stress-hypo-responsive-period (SHRP) on postnatal day (PND) 2, 4, 6 or 9. The present study shows that an injection of saline on PND 2 decreases the apomorphine-induced gnawing score in adult APO-SUS rats, but increases this score in adult APO-UNSUS rats; clonidine given on this day has no effect. An injection of saline on PND 4 decreases the apomorphine score in adult APO-SUS rats, but has no effect in adult APO-UNSUS rats. An injection of clonidine on PND 4 counteracts the long-term after-effects of a saline injection on this PND in adult APO-SUS rats, but has no effect in adult APO-UNSUS rats. Finally, an injection of clonidine on PND 9 has no effect on the apomorphine score in adult APO-SUS rats, but increases this score in adult APO-UNSUS rats; saline given on this day has no effect. It is concluded that the long-term after-effects of early postnatal stressors depend on the interrelationship between, rather than the separate impact of, the genetic background of the rat, the nature of the event, and time of exposure to the event, thereby implying that these factors direct the phenotypic expression of a particular genotype at adult age.
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Affiliation(s)
- S B Degen
- Department of Psychoneuropharmacology, University of Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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