1
|
Mondal S, Rathor R, Singh SN, Suryakumar G. miRNA and leptin signaling in metabolic diseases and at extreme environments. Pharmacol Res Perspect 2024; 12:e1248. [PMID: 39017237 PMCID: PMC11253706 DOI: 10.1002/prp2.1248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 05/27/2024] [Accepted: 07/04/2024] [Indexed: 07/18/2024] Open
Abstract
The burden of growing concern about the dysregulation of metabolic processes arises due to complex interplay between environment and nutrition that has great impact on genetics and epigenetics of an individual. Thereby, any abnormality at the level of food intake regulating hormones may contribute to the development of metabolic diseases in any age group due to malnutrition, overweight, changing lifestyle, and exposure to extreme environments such as heat stress (HS), cold stress, or high altitude (HA). Hormones such as leptin, adiponectin, ghrelin, and cholecystokinin regulate appetite and satiety to maintain energy homeostasis. Leptin, an adipokine and a pleiotropic hormone, play major role in regulating the food intake, energy gain and energy expenditure. Using in silico approach, we have identified the major genes (LEP, LEPR, JAK2, STAT3, NPY, POMC, IRS1, SOCS3) that play crucial role in leptin signaling pathway. Further, eight miRNAs (hsa-miR-204-5p, hsa-miR-211-5p, hsa-miR-30, hsa-miR-3163, hsa-miR-33a-3p, hsa-miR-548, hsa-miR-561-3p, hsa-miR-7856-5p) from TargetScan 8.0 database were screened out that commonly target these genes. The role of these miRNAs should be explored as they might play vital role in regulating the appetite, energy metabolism, metabolic diseases (obesity, type 2 diabetes, cardiovascular diseases, inflammation), and to combat extreme environments. The miRNAs regulating leptin signaling and appetite may be useful for developing novel therapeutics for metabolic diseases.
Collapse
Affiliation(s)
- Samrita Mondal
- Defence Institute of Physiology and Allied SciencesDelhiIndia
| | - Richa Rathor
- Defence Institute of Physiology and Allied SciencesDelhiIndia
| | - Som Nath Singh
- Defence Institute of Physiology and Allied SciencesDelhiIndia
| | | |
Collapse
|
2
|
Della Guardia L, Luzi L, Codella R. Muscle-UCP3 in the regulation of energy metabolism. Mitochondrion 2024; 76:101872. [PMID: 38499130 DOI: 10.1016/j.mito.2024.101872] [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: 08/10/2023] [Revised: 03/10/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
Uncoupling protein-3 (UCP3) is a mitochondria-regulatory protein with potential energy- homeostatic functions. This study explores the role of UCP3 in the regulation of muscle- and energy metabolism. UCP3 is critical for tuning substrate utilization, favoring lipid oxidation, particularly in conditions of high-fat availability. While UCP3 is non-essential for lipid oxidation during energy excess, it proves vital during fasting, indicating an energy-homeostatic trait. Preliminary evidence indicates UCP3' promotion of glucose uptake and oxidation, at least in conditions of high glucose/low fat availability. However, the dynamics of how fats and glucose differentially influence UCP3 remain undefined. UCP3 exhibits inducible proton transport and uncoupling activity, operating in a dual manner: a resting state with no/low activity and an activated state in the presence of activators. Uncoupling may enhance thermogenesis in specific conditions and in the presence of activators such as fatty acids, thyroid hormones, and catecholamines. This energy-dissipative activity adapts to varying energy availability, balancing energy dissipation with fatty acid oxidation to optimize whole-body energy homeostasis: fasting triggers UCP3 upregulation, enhancing lipid utilization while suppressing uncoupling. Additionally, UCP3 upregulation induces glucose and lipid disposal from the bloodstream and decreases tri-/diglyceride storage in muscle. This process improves mitochondrial functionality and insulin signaling, leading to enhanced systemicgluco-metabolic balance and protection from metabolic conditions. Reviewed evidence suggests that UCP3 plays a crucial role in adapting the system to changing energy conditions. However, the precise role of UCP3 in regulating metabolism requires further elucidation.
Collapse
Affiliation(s)
- Lucio Della Guardia
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy
| | - Livio Luzi
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy; Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milano, Italy
| | - Roberto Codella
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy; Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milano, Italy.
| |
Collapse
|
3
|
Potes Y, Díaz-Luis A, Bermejo-Millo JC, Pérez-Martínez Z, de Luxán-Delgado B, Rubio-González A, Menéndez-Valle I, Gutiérrez-Rodríguez J, Solano JJ, Caballero B, Vega-Naredo I, Coto-Montes A. Melatonin Alleviates the Impairment of Muscle Bioenergetics and Protein Quality Control Systems in Leptin-Deficiency-Induced Obesity. Antioxidants (Basel) 2023; 12:1962. [PMID: 38001815 PMCID: PMC10669624 DOI: 10.3390/antiox12111962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 11/26/2023] Open
Abstract
Leptin is critically compromised in the major common forms of obesity. Skeletal muscle is the main effector tissue for energy modification that occurs as a result of the effect of endocrine axes, such as leptin signaling. Our study was carried out using skeletal muscle from a leptin-deficient animal model, in order to ascertain the importance of this hormone and to identify the major skeletal muscle mechanisms affected. We also examined the therapeutic role of melatonin against leptin-induced muscle wasting. Here, we report that leptin deficiency stimulates fatty acid β-oxidation, which results in mitochondrial uncoupling and the suppression of mitochondrial oxidative damage; however, it increases cytosolic oxidative damage. Thus, different nutrient-sensing pathways are disrupted, impairing proteostasis and promoting lipid anabolism, which induces myofiber degeneration and drives oxidative type I fiber conversion. Melatonin treatment plays a significant role in reducing cellular oxidative damage and regulating energy homeostasis and fuel utilization. Melatonin is able to improve both glucose and mitochondrial metabolism and partially restore proteostasis. Taken together, our study demonstrates melatonin to be a decisive mitochondrial function-fate regulator in skeletal muscle, with implications for resembling physiological energy requirements and targeting glycolytic type II fiber recovery.
Collapse
Affiliation(s)
- Yaiza Potes
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), 33006 Oviedo, Spain
| | - Andrea Díaz-Luis
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Juan C. Bermejo-Millo
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), 33006 Oviedo, Spain
| | - Zulema Pérez-Martínez
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Microbiology Service, Central University Hospital of Asturias, 33011 Oviedo, Spain
| | - Beatriz de Luxán-Delgado
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Adrian Rubio-González
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Iván Menéndez-Valle
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), 33006 Oviedo, Spain
- Immunology Service, Central University Hospital of Asturias, 33011 Oviedo, Spain
| | - José Gutiérrez-Rodríguez
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Geriatric Service, Monte Naranco Hospital, 33012 Oviedo, Spain
| | - Juan J. Solano
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Geriatric Service, Monte Naranco Hospital, 33012 Oviedo, Spain
| | - Beatriz Caballero
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), 33006 Oviedo, Spain
| | - Ignacio Vega-Naredo
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), 33006 Oviedo, Spain
| | - Ana Coto-Montes
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Neurosciences of the Principality of Asturias (INEUROPA), 33006 Oviedo, Spain
| |
Collapse
|
4
|
Guo L, Quan M, Pang W, Yin Y, Li F. Cytokines and exosomal miRNAs in skeletal muscle-adipose crosstalk. Trends Endocrinol Metab 2023; 34:666-681. [PMID: 37599201 DOI: 10.1016/j.tem.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/14/2023] [Accepted: 07/25/2023] [Indexed: 08/22/2023]
Abstract
Skeletal muscle and adipose tissues (ATs) are secretory organs that release secretory factors including cytokines and exosomes. These factors mediate muscle-adipose crosstalk to regulate systemic metabolism via paracrine and endocrine pathways. Myokines and adipokines are cytokines secreted by skeletal muscle and ATs, respectively. Exosomes loaded with nucleic acids, proteins, lipid droplets, and organelles can fuse with the cytoplasm of target cells to perform regulatory functions. A major regulatory component of exosomes is miRNA. In addition, numerous novel myokines and adipokines have been identified through technological innovations. These discoveries have identified new biomarkers and sparked new insights into the molecular regulation of skeletal muscle growth and adipose deposition. The knowledge may contribute to potential diagnostic and therapeutic targets in metabolic disease.
Collapse
Affiliation(s)
- Liu Guo
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China; University of Chinese Academy of Sciences, Beijing 101408, China
| | - Menchus Quan
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Weijun Pang
- Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Yulong Yin
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Fengna Li
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
5
|
Sharma Y, Galvão AM. Maternal obesity and ovarian failure: is leptin the culprit? Anim Reprod 2023; 19:e20230007. [PMID: 36855701 PMCID: PMC9968511 DOI: 10.1590/1984-3143-ar2023-0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/24/2023] [Indexed: 02/22/2023] Open
Abstract
At the time of its discovery and characterization in 1994, leptin was mostly considered a metabolic hormone able to regulate body weight and energy homeostasis. However, in recent years, a great deal of literature has revealed leptin's pleiotropic nature, through its involvement in numerous physiological contexts including the regulation of the female reproductive tract and ovarian function. Obesity has been largely associated with infertility, and leptin signalling is known to be dysregulated in the ovaries of obese females. Hence, the disruption of ovarian leptin signalling was shown to contribute to the pathophysiology of ovarian failure in obese females, affecting transcriptional programmes in the gamete and somatic cells. This review attempts to uncover the underlying mechanisms contributing to female infertility associated with obesity, as well as to shed light on the role of leptin in the metabolic dysregulation within the follicle, the effects on the oocyte epigenome, and the potential long-term consequence to embryo programming.
Collapse
Affiliation(s)
- Yashaswi Sharma
- Institute of Animal Reproduction and Food Research of PAS, Department of Reproductive Immunology and Pathology, Olsztyn, Poland
| | - António Miguel Galvão
- Institute of Animal Reproduction and Food Research of PAS, Department of Reproductive Immunology and Pathology, Olsztyn, Poland,Babraham Institute, Epigenetics Programme, Cambridge, United Kingdom UK,Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom UK,Corresponding author: ;
| |
Collapse
|
6
|
De Jesus AN, Henry BA. The role of oestrogen in determining sexual dimorphism in energy balance. J Physiol 2023; 601:435-449. [PMID: 36117117 PMCID: PMC10092637 DOI: 10.1113/jp279501] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/26/2022] [Indexed: 02/03/2023] Open
Abstract
Energy balance is determined by caloric intake and the rate at which energy is expended, with the latter comprising resting energy expenditure, physical activity and adaptive thermogenesis. The regulation of both energy intake and expenditure exhibits clear sexual dimorphism, with young women being relatively protected against weight gain and the development of cardiometabolic diseases. Preclinical studies have indicated that females are more sensitive to the satiety effects of leptin and insulin compared to males. Furthermore, females have greater thermogenic activity than males, whereas resting energy expenditure is generally higher in males than females. In addition to this, in post-menopausal women, the decline in sex steroid concentration, particularly in oestrogen, is associated with a shift in the distribution of adipose tissue and overall increased propensity to gain weight. Oestrogens are known to regulate energy balance and weight homeostasis via effects on both food intake and energy expenditure. Indeed, 17β-oestradiol treatment increases melanocortin signalling in the hypothalamus to cause satiety. Furthermore, oestrogenic action at the ventromedial hypothalamus has been linked with increased energy expenditure in female mice. We propose that oestrogen action on energy balance is multi-faceted and is fundamental to determining sexual dimorphism in weight control. Furthermore, evidence suggests that the decline in oestrogen levels leads to increased risk of weight gain and development of cardiometabolic disease in women across the menopausal transition.
Collapse
Affiliation(s)
- Anne Nicole De Jesus
- Metabolism, Obesity and Diabetes Program, Biomedicine, Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria, Australia
| | - Belinda A Henry
- Metabolism, Obesity and Diabetes Program, Biomedicine, Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
7
|
Tian JJ, Levy M, Zhang X, Sinnott R, Maddela R. Counteracting Health Risks by Modulating Homeostatic Signaling. Pharmacol Res 2022; 182:106281. [PMID: 35661711 DOI: 10.1016/j.phrs.2022.106281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/14/2022] [Accepted: 05/27/2022] [Indexed: 10/18/2022]
Abstract
Homeostasis was initially conceptualized by Bernard and Cannon around a century ago as a steady state of physiological parameters that vary within a certain range, such as blood pH, body temperature, and heart rate1,2. The underlying mechanisms that maintain homeostasis are explained by negative feedbacks that are executed by the neuronal, endocrine, and immune systems. At the cellular level, homeostasis, such as that of redox and energy steady state, also exists and is regulated by various cell signaling pathways. The induction of homeostatic mechanism is critical for human to adapt to various disruptive insults (stressors); while on the other hand, adaptation occurs at the expense of other physiological processes and thus runs the risk of collateral damages, particularly under conditions of chronic stress. Conceivably, anti-stress protection can be achieved by stressor-mimicking medicinals that elicit adaptive responses prior to an insult and thereby serve as health risk countermeasures; and in situations where maladaptation may occur, downregulating medicinals could be used to suppress the responses and prevent subsequent pathogenesis. Both strategies are preemptive interventions particularly suited for individuals who carry certain lifestyle, environmental, or genetic risk factors. In this article, we will define and characterize a new modality of prophylactic intervention that forestalls diseases via modulating homeostatic signaling. Moreover, we will provide evidence from the literature that support this concept and distinguish it from other homeostasis-related interventions such as adaptogen, hormesis, and xenohormesis.
Collapse
Affiliation(s)
- Junqiang J Tian
- USANA Health Science, Inc., 3838 Parkway Blvd, Salt Lake City, UT 84121, USA.
| | - Mark Levy
- USANA Health Science, Inc., 3838 Parkway Blvd, Salt Lake City, UT 84121, USA
| | - Xuekai Zhang
- Beijing University of Chinese Medicine, No. 11, Bei San Huan Dong Lu, Chaoyang District, Beijing100029, China; US Center for Chinese Medicine, 14801 Physicians lane, 171 A 2nd Floor, #281, Rockville MD 20850, USA
| | - Robert Sinnott
- USANA Health Science, Inc., 3838 Parkway Blvd, Salt Lake City, UT 84121, USA
| | - Rolando Maddela
- USANA Health Science, Inc., 3838 Parkway Blvd, Salt Lake City, UT 84121, USA
| |
Collapse
|
8
|
Shrestha R, Johnson E, Byrne FL. Exploring the therapeutic potential of mitochondrial uncouplers in cancer. Mol Metab 2021; 51:101222. [PMID: 33781939 PMCID: PMC8129951 DOI: 10.1016/j.molmet.2021.101222] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Mitochondrial uncouplers are well-known for their ability to treat a myriad of metabolic diseases, including obesity and fatty liver diseases. However, for many years now, mitochondrial uncouplers have also been evaluated in diverse models of cancer in vitro and in vivo. Furthermore, some mitochondrial uncouplers are now in clinical trials for cancer, although none have yet been approved for the treatment of cancer. SCOPE OF REVIEW In this review we summarise published studies in which mitochondrial uncouplers have been investigated as an anti-cancer therapy in preclinical models. In many cases, mitochondrial uncouplers show strong anti-cancer effects both as single agents, and in combination therapies, and some are more toxic to cancer cells than normal cells. Furthermore, the mitochondrial uncoupling mechanism of action in cancer cells has been described in detail, with consistencies and inconsistencies between different structural classes of uncouplers. For example, many mitochondrial uncouplers decrease ATP levels and disrupt key metabolic signalling pathways such as AMPK/mTOR but have different effects on reactive oxygen species (ROS) production. Many of these effects oppose aberrant phenotypes common in cancer cells that ultimately result in cell death. We also highlight several gaps in knowledge that need to be addressed before we have a clear direction and strategy for applying mitochondrial uncouplers as anti-cancer agents. MAJOR CONCLUSIONS There is a large body of evidence supporting the therapeutic use of mitochondrial uncouplers to treat cancer. However, the long-term safety of some uncouplers remains in question and it will be critical to identify which patients and cancer types would benefit most from these agents.
Collapse
Affiliation(s)
- Riya Shrestha
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, 2052, Australia
| | - Edward Johnson
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, 2052, Australia
| | - Frances L Byrne
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, 2052, Australia.
| |
Collapse
|
9
|
Ahmad SF, Mehrotra A, Charles S, Ganai NA. Analysis of selection signatures reveals important insights into the adaptability of high-altitude Indian sheep breed Changthangi. Gene 2021; 799:145809. [PMID: 34224833 DOI: 10.1016/j.gene.2021.145809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 06/14/2021] [Accepted: 06/30/2021] [Indexed: 12/21/2022]
Abstract
Changthangi is a high-altitude sheep breed of India that is adapted to cold and hypoxic climate of Himalayas. In the present study, we analysed population structure of Changthangi and contrasted it with selected Indian and European commercial sheep breeds to detect genomic regions under positive selection. The Illumina OvineSNP50v1 genotype data on 292 animals from seven different sheep breeds i.e., Changthangi (n = 29), Garole (n = 26), Deccani (n = 24), Tibetan (n = 37), Rambouillet (n = 102) and Australian Merino (n = 50) was used. European Mouflon (n = 24) was used as an out-group for studying the stratification and phylogenetic lineage. While the principal component analysis (PCA) revealed Changthangi to cluster with Tibetan sheep; TREEMIX and ADMIXTURE results also detected the introgression of lowland Indian sheep inheritance in Changthangi. Changthangi sheep were compared with other breed groups as reference i.e., commercial (Australian Merino and Rambouillet), Indian (Deccani, Garole and Tibetan) and breeds inhabiting plains (Australian Merino, Rambouillet, Deccani and Garole). Genomic comparisons of Changthangi using cross population extended haplotype homozygosity (XP-EHH) showed multiple functional regions present on Ovis aries (Oar) chromosomes 2, 3, 6 and 18 to be under selection in Changthangi sheep. These regions were related with adaptation to climatic and hypoxic stressors, fleece characteristics and functioning of immune and reproductive systems. UCP genes, associated with adaptation to cold and hypoxic conditions, were the main loci under positive selection in Changthangi sheep population. The selection signals in Indian and European commercial sheep breeds were mainly associated with body weight and carcass traits. Furthermore, selection signals found in different comparisons were found to be part of different quantitative trait loci (QTLs) associated with important traits in different breed classes. The genes present in these regions are suitable candidates for future studies on the genetic mechanisms underlying high-altitude adaptation.
Collapse
Affiliation(s)
- Sheikh Firdous Ahmad
- ICAR-National Research Centre on Pig, Rani, Guwahati 781131, Assam, India; ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India.
| | - Arnav Mehrotra
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India; Animal Genomics, ETH Zürich, Zürich, Switzerland.
| | - Sona Charles
- ICAR-Indian Institute of Spices Research, Kozhikode 673012, Kerala, India.
| | - Nazir Ahmad Ganai
- Sher-e-Kashmir University of Agricultural Sciences and Technology, Kashmir, Shalimar, Srinagar 190006, J&K, India.
| |
Collapse
|
10
|
Mansur RB, Lee Y, McIntyre RS, Brietzke E. What is bipolar disorder? A disease model of dysregulated energy expenditure. Neurosci Biobehav Rev 2020; 113:529-545. [PMID: 32305381 DOI: 10.1016/j.neubiorev.2020.04.006] [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: 12/10/2019] [Revised: 03/30/2020] [Accepted: 04/05/2020] [Indexed: 12/24/2022]
Abstract
Advances in the understanding and management of bipolar disorder (BD) have been slow to emerge. Despite notable recent developments in neurosciences, our conceptualization of the nature of this mental disorder has not meaningfully progressed. One of the key reasons for this scenario is the continuing lack of a comprehensive disease model. Within the increasing complexity of modern research methods, there is a clear need for an overarching theoretical framework, in which findings are assimilated and predictions are generated. In this review and hypothesis article, we propose such a framework, one in which dysregulated energy expenditure is a primary, sufficient cause for BD. Our proposed model is centered on the disruption of the molecular and cellular network regulating energy production and expenditure, as well its potential secondary adaptations and compensatory mechanisms. We also focus on the putative longitudinal progression of this pathological process, considering its most likely periods for onset, such as critical periods that challenges energy homeostasis (e.g. neurodevelopment, social isolation), and the resulting short and long-term phenotypical manifestations.
Collapse
Affiliation(s)
- Rodrigo B Mansur
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
| | - Yena Lee
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Elisa Brietzke
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Kingston General Hospital, Providence Care Hospital, Department of Psychiatry, Queen's University School of Medicine, Kingston, ON, Canada
| |
Collapse
|
11
|
Could leptin be responsible for the reproductive dysfunction in obese men? Reprod Biol 2020; 20:106-110. [DOI: 10.1016/j.repbio.2020.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/12/2022]
|
12
|
Gregg BA, Parker PA, Waller KM, Schneider LG, Garcia M, Bradford B, Daniel JA, Whitlock BK. Effects of central and peripheral administration of an acute-phase protein, α-1-acid-glycoprotein, on feed intake and rectal temperature in sheep. J Anim Sci 2019; 97:4783-4791. [PMID: 31679022 PMCID: PMC6915238 DOI: 10.1093/jas/skz336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/29/2019] [Indexed: 12/21/2022] Open
Abstract
In rodents, an acute-phase protein, α-1-acid-glycoprotein (AGP), was shown to provide a link between inflammation and suppression of feed intake by acting as a leptin receptor agonist. The objective of this study was to determine the effects of AGP on feed intake and rectal temperature in sheep. Ewes were ovariectomized, implanted with a cannula into a lateral ventricle of the brain, and kept indoors in individual pens. Feed intake and rectal temperature were determined for sheep in all experiments. In the first experiment, ewes (n = 4) received 1 of 4 treatments [0 (control), 0.012 (low), 0.06 (medium), or 0.30 (high) mg/kg BW AGP] into the lateral ventricle (ICV). All sheep received all treatments in a Latin square design balanced for carryover effects with 10 d between treatments. In the second experiment, ewes (n = 10) received 1 of 2 treatments (0 and 3 mg/kg BW of AGP) intravenously (IV) in a completely randomized design. In the third experiment, ewes (n = 19) received peripheral treatments (IV) of an antipyretic [0 (control) or 2.2 mg/kg BW flunixin meglumine (FLU)] 30 min before receiving central AGP [0 (control) or 0.3 mg/kg BW of AGP] in a completely randomized design. All data were analyzed using a mixed model analysis of variance and tested for effects of treatment, time, and the interaction of treatment and time. Cumulative 48-h feed intake after administration of treatments was also determined. In the first experiment, there was no effect of ICV treatment (P = 0.37) on feed intake rate or on cumulative feed intake (P = 0.31). There was an effect of ICV treatment (P = 0.002) on rectal temperatures, which were greater (P < 0.05) after the high dose of centrally administered AGP. In the second experiment, there was no effect of AGP administration IV on feed intake rate (P = 0.98), on cumulative feed intake (P = 0.41) or on rectal temperature (P = 0.71). In the third experiment, there was an effect of central AGP treatment (P < 0.0001) and an interaction of central AGP and time (P < 0.0001) on rectal temperature, whereas FLU had no effect (P = 0.93), demonstrating that AGP increased rectal temperatures regardless of antipyretic treatment. These results indicate that central AGP increases rectal temperature in sheep by pathways that do not involve prostaglandins. Further research is needed to determine whether AGP may be an important integrator of energy balance and inflammation.
Collapse
Affiliation(s)
- Brittany A Gregg
- College of Veterinary Medicine, University of Tennessee, Knoxville, TN
- Department of Animal Science, University of Tennessee, Knoxville, TN
| | - Paxton A Parker
- College of Veterinary Medicine, University of Tennessee, Knoxville, TN
| | - Kathryn M Waller
- College of Veterinary Medicine, University of Tennessee, Knoxville, TN
| | | | - Miriam Garcia
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS
| | - Barry Bradford
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS
| | - Joseph A Daniel
- School of Mathematical and Natural Sciences, Berry College, Mount Berry, GA
| | - Brian K Whitlock
- College of Veterinary Medicine, University of Tennessee, Knoxville, TN
- Department of Animal Science, University of Tennessee, Knoxville, TN
| |
Collapse
|
13
|
Palmer BF, Clegg DJ. Strategies to Counter Weight Loss-Induced Reductions in Metabolic Rate. Curr Sports Med Rep 2019; 18:258-265. [DOI: 10.1249/jsr.0000000000000610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
14
|
Bastardot F, Marques-Vidal P, Vollenweider P. Association of body temperature with obesity. The CoLaus study. Int J Obes (Lond) 2018; 43:1026-1033. [PMID: 30250242 PMCID: PMC6760582 DOI: 10.1038/s41366-018-0218-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/09/2018] [Accepted: 08/29/2018] [Indexed: 12/19/2022]
Abstract
Background and aims There is conflicting evidence regarding the association between body temperature and obesity. We aimed to assess the associations between body temperature and several adiposity and metabolic markers according to gender and menopausal status in a large population-based sample. Methods The data collected between 2009 and 2012 from 4224 participants (mean age 57.3 ± 10.4 years, 2225 women) of the CoLaus study (Lausanne, Switzerland). Body temperature was measured at the tympanic membrane. Results Mean body temperature was 36.1 ± 0.4, 36.4 ± 0.4 and 36.3 ± 0.4 °C in men, premenopausal, and postmenopausal women, respectively (p < 0.001). In men and postmenopausal women, body temperature was positively and significantly (p < 0.05) associated with body mass index (Spearman correlation coefficients 0.157 and 0.083, respectively), waist (r = 0.163 and r = 0.104), waist to hip ratio (r = 0.187 and r = 0.132), body area (r = 0.094 and r = 0.085), resting heart rate (r = 0.227 and r = 182), glucose (r = 0.104 and r = 0.088) and insulin (r = 0.148 and r = 0.117). Except for body area and BMI in postmenopausal women, all associations remained significant after multivariable adjustment. In premenopausal women, body temperature was positively associated with resting heart rate (r = 0.140) and insulin (r = 0.170), and no significant associations were found after multivariable adjustment. Conclusion Body temperature is strongly associated with obesity markers in men and postmenopausal women. The absence of association in premenopausal women might be due to the influence of the menstrual cycle.
Collapse
Affiliation(s)
- François Bastardot
- Department of Medicine, Internal Medicine, Lausanne University hospital, Lausanne, Switzerland
| | - Pedro Marques-Vidal
- Department of Medicine, Internal Medicine, Lausanne University hospital, Lausanne, Switzerland
| | - Peter Vollenweider
- Department of Medicine, Internal Medicine, Lausanne University hospital, Lausanne, Switzerland.
| |
Collapse
|
15
|
Côté I, Sakarya Y, Green SM, Morgan D, Carter CS, Tümer N, Scarpace PJ. iBAT sympathetic innervation is not required for body weight loss induced by central leptin delivery. Am J Physiol Endocrinol Metab 2018; 314:E224-E231. [PMID: 29089334 PMCID: PMC5899217 DOI: 10.1152/ajpendo.00219.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We evaluated the contribution of brown adipose tissue (BAT) sympathetic innervation on central leptin-mediated weight loss. In a short- and long-term study, F344BN rats were submitted to either a denervation of interscapular BAT (Denervated) or a sham operation (Sham). Animals from each group received the Ob (Leptin) or green fluorescent protein (GFP; Control) gene through a single injection of recombinant adeno-associated virus delivered centrally. Changes in body weight were recorded for 14 or 35 days, after which adipose tissues and skeletal muscles were weighed. In both studies, hypothalamic phosphorylated STAT3 (P-STAT3) was significantly higher in Sham-Leptin and Denervated-Leptin groups compared with their respective Control groups ( P < 0.01), indicating that leptin signaling was enhanced at the end point. We measured uncoupling protein 1 (UCP1), a marker of BAT thermogenic activity, and found a significant induction in Leptin in Sham animals ( P < 0.001) but not in Denervated animals, demonstrating that BAT UCP1 protein was only induced in Sham rats. Both Sham-Leptin and Denervated-Leptin rats lost ~15% of their initial body weight ( P < 0.001) by day 14 and reached a maximum of 18% body weight loss that stabilized over week 3 of treatment, indicating that sympathetic outflow to BAT is not required for leptin-mediated weight loss. In summary, interscapular BAT (iBAT) denervation did not prevent body weight loss following central leptin gene delivery. The present data show that sympathetic innervation of iBAT is not essential for leptin-induced body weight loss.
Collapse
Affiliation(s)
- Isabelle Côté
- Department of Pharmacology and Therapeutics, University of Florida , Gainesville, Florida
| | - Yasemin Sakarya
- Department of Pharmacology and Therapeutics, University of Florida , Gainesville, Florida
| | - Sara M Green
- Department of Pharmacology and Therapeutics, University of Florida , Gainesville, Florida
| | - Drake Morgan
- Department of Psychiatry, University of Florida , Gainesville, Florida
| | - Christy S Carter
- Department of Aging and Geriatric Research, University of Florida , Gainesville, Florida
| | - Nihal Tümer
- Department of Pharmacology and Therapeutics, University of Florida , Gainesville, Florida
| | - Philip J Scarpace
- Department of Pharmacology and Therapeutics, University of Florida , Gainesville, Florida
| |
Collapse
|
16
|
Fuller-Jackson JP, Clarke IJ, Rao A, Henry BA. Exercise counteracts the homeostatic decrease in thermogenesis caused by caloric restriction in sheep. FASEB J 2018; 32:3859-3869. [PMID: 29455575 DOI: 10.1096/fj.201701504r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Caloric restriction causes a homeostatic reduction in thermogenesis. We aimed to determine whether exercise could counteract this. We studied four groups of normal-weight ewes ( n = 5), including control sedentary fed ad libitum, exercise fed ad libitum (30 min/d, 5 d/wk), diet-restricted (70% of ad libitum food intake), and combined diet and exercise. Temperature probes implanted in sternal and retroperitoneal adipose tissue and skeletal muscle measured thermogenesis. After the 4-wk intervention, hypothalami were collected for in situ hybridization, and fat and muscle biopsies were collected for real-time PCR and Western blotting. Combined diet and exercise reduced adiposity ( P < 0.05). Caloric restriction alone reduced overnight temperatures in sternal and retroperitoneal fat ( P < 0.05), which was counteracted by exercise ( P < 0.05). Exercise did not induce expression of cellular markers of browning in adipose tissue. There was no effect of diet or exercise on skeletal muscle thermogenesis. Combined diet and exercise increased the expression of neuropeptide Y and agouti-related protein in the hypothalamic arcuate nucleus ( P < 0.05), consistent with reduced adiposity. Gene expressions of key hypothalamic appetite-regulating peptides were not associated with altered thermogenesis. We demonstrate that exercise counteracts the inhibitory effect of caloric restriction to restore thermogenesis in adipose tissue of sheep.-Fuller-Jackson, J.-P., Clarke, I. J., Rao, A., Henry, B. A. Exercise counteracts the homeostatic decrease in thermogenesis caused by caloric restriction in sheep.
Collapse
Affiliation(s)
- John-Paul Fuller-Jackson
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Iain J Clarke
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Alexandra Rao
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Belinda A Henry
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
17
|
Luglio HF, Sulistyoningrum DC, Huriyati E, Lee YY, Wan Muda WAM. The Gene-Lifestyle Interaction on Leptin Sensitivity and Lipid Metabolism in Adults: A Population Based Study. Nutrients 2017; 9:nu9070716. [PMID: 28686191 PMCID: PMC5537831 DOI: 10.3390/nu9070716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/26/2017] [Accepted: 06/30/2017] [Indexed: 12/26/2022] Open
Abstract
Background: Obesity has been associated with leptin resistance and this might be caused by genetic factors. The aim of this study was to investigate the gene-lifestyle interaction between −866G/A UCP2 (uncoupling protein 2) gene polymorphism, dietary intake and leptin in a population based study. Methods: This is a cross sectional study conducted in adults living at urban area of Yogyakarta, Indonesia. Data of adiposity, lifestyle, triglyceride, high density lipoprotein (HDL) cholesterol, leptin and UCP2 gene polymorphism were obtained in 380 men and female adults. Results: UCP2 gene polymorphism was not significantly associated with adiposity, leptin, triglyceride, HDL cholesterol, dietary intake and physical activity (all p > 0.05). Leptin was lower in overweight subjects with AA + GA genotypes than those with GG genotype counterparts (p = 0.029). In subjects with AA + GA genotypes there was a negative correlation between leptin concentration (r = −0.324; p < 0.0001) and total energy intake and this correlation was not seen in GG genotype (r = −0.111; p = 0.188). Conclusions: In summary, we showed how genetic variation in −866G/A UCP2 affected individual response to leptin production. AA + GA genotype had a better leptin sensitivity shown by its response in dietary intake and body mass index (BMI) and this explained the protective effect of A allele to obesity.
Collapse
Affiliation(s)
- Harry Freitag Luglio
- Department of Nutrition and Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | | | - Emy Huriyati
- Department of Nutrition and Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Yi Yi Lee
- School of Health Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia.
| | | |
Collapse
|
18
|
Henry BA, Pope M, Birtwistle M, Loughnan R, Alagal R, Fuller-Jackson JP, Perry V, Budge H, Clarke IJ, Symonds ME. Ontogeny and Thermogenic Role for Sternal Fat in Female Sheep. Endocrinology 2017; 158:2212-2225. [PMID: 28431116 DOI: 10.1210/en.2017-00081] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/14/2017] [Indexed: 02/05/2023]
Abstract
Brown adipose tissue acting through a unique uncoupling protein (UCP1) has a critical role in preventing hypothermia in newborn sheep but is then thought to rapidly disappear during postnatal life. The extent to which the anatomical location of fat influences postnatal development and thermogenic function in adulthood, particularly following feeding, is unknown, and we examined both in our study. Changes in gene expression of functionally important pathways (i.e., thermogenesis, development, adipogenesis, and metabolism) were compared between sternal and retroperitoneal fat depots together with a representative skeletal muscle over the first month of postnatal life, coincident with the loss of brown fat and the accumulation of white fat. In adult sheep, implanted temperature probes were used to characterize the thermogenic response of fat and muscle to feeding and the effects of reduced or increased adiposity. UCP1 was more abundant in sternal fat than in retroperitoneal fat and was retained only in the sternal depot of adults. Distinct differences in the abundance of gene pathway markers were apparent between tissues, with sternal fat exhibiting some similarities with muscle that were not apparent in the retroperitoneal depot. In adults, the postprandial rise in temperature was greater and more prolonged in sternal fat than in retroperitoneal fat and muscle, a difference that was maintained with altered adiposity. In conclusion, sternal adipose tissue retains UCP1 into adulthood, when it shows a greater thermogenic response to feeding than do muscle and retroperitoneal fat. Sternal fat may be more amenable to targeted interventions that promote thermogenesis in large mammals.
Collapse
Affiliation(s)
- Belinda A Henry
- Metabolic Disease and Obesity Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Mark Pope
- Early Life Research Unit, Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - Mark Birtwistle
- Early Life Research Unit, Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - Rachael Loughnan
- Metabolic Disease and Obesity Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Reham Alagal
- Early Life Research Unit, Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - John-Paul Fuller-Jackson
- Metabolic Disease and Obesity Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Viv Perry
- School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington LE12 5RD, United Kingdom
| | - Helen Budge
- Early Life Research Unit, Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - Iain J Clarke
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Michael E Symonds
- Early Life Research Unit, Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom
- Nottingham Digestive Disease Centre and Biomedical Research Unit, School of Medicine, Queen's Medical Centre, The University of Nottingham, Nottingham NG7 2UH, United Kingdom
| |
Collapse
|
19
|
Hewagalamulage SD, Clarke IJ, Rao A, Henry BA. Ewes With Divergent Cortisol Responses to ACTH Exhibit Functional Differences in the Hypothalamo-Pituitary-Adrenal (HPA) Axis. Endocrinology 2016; 157:3540-9. [PMID: 27414744 DOI: 10.1210/en.2016-1287] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Within any population, the cortisol response to ACTH covers a considerable range. High responders (HRs) exhibit a greater cortisol secretory response to stress or ACTH, compared with individuals classified as low cortisol responders (LRs). We administered ACTH (0.2 μg/kg, iv) to 160 female sheep and selected subpopulations of animals as LR and HR. In the present study, we aimed to characterize the hypothalamo-pituitary-adrenal axis in HR and LR and to identify factors that underlie the differing cortisol responses to ACTH. Hypothalami, pituitaries, and adrenals were collected from nonstressed HR and LR ewes. Expression of genes for CRH, arginine vasopressin (AVP), oxytocin, glucocorticoid receptor, and mineralocorticoid receptor were measured by in situ hybridization in the paraventricular nucleus of the hypothalamus, and proopiomelanocortin (POMC) gene expression was measured in the anterior pituitary. Expression of CRH, AVP, and POMC was higher in HR, with no differences in either glucocorticoid receptor or mineralocorticoid receptor expression. Oxytocin expression was greater in LR. In the adrenal gland, real-time PCR analysis indicated that expression of the ACTH receptor and a range of steroidogenic enzymes was similar in HR and LR. Adrenal weights, the cortex to medulla ratio and adrenal cortisol content were also similar in LR and HR. In conclusion, LR and HR display innate differences in the steady-state expression of CRH, AVP, oxytocin, and POMC, indicating that selection for cortisol responsiveness identifies distinct subpopulations that exhibit innate differences in the gene expression/function of hypothalamo-pituitary-adrenal axis markers.
Collapse
Affiliation(s)
- Sakda D Hewagalamulage
- Metabolic Disease and Obesity Program (S.D.H., B.A.H.) and Neuroscience Program (I.J.C., A.R.), Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
| | - Iain J Clarke
- Metabolic Disease and Obesity Program (S.D.H., B.A.H.) and Neuroscience Program (I.J.C., A.R.), Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
| | - Alexandra Rao
- Metabolic Disease and Obesity Program (S.D.H., B.A.H.) and Neuroscience Program (I.J.C., A.R.), Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
| | - Belinda A Henry
- Metabolic Disease and Obesity Program (S.D.H., B.A.H.) and Neuroscience Program (I.J.C., A.R.), Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
| |
Collapse
|
20
|
Hewagalamulage SD, Lee TK, Clarke IJ, Henry BA. Stress, cortisol, and obesity: a role for cortisol responsiveness in identifying individuals prone to obesity. Domest Anim Endocrinol 2016; 56 Suppl:S112-20. [PMID: 27345309 DOI: 10.1016/j.domaniend.2016.03.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 11/22/2022]
Abstract
There is a strong inter-relationship between activation of the hypothalamo-pituitary-adrenal axis and energy homeostasis. Patients with abdominal obesity have elevated cortisol levels. Furthermore, stress and glucocorticoids act to control both food intake and energy expenditure. In particular, glucocorticoids are known to increase the consumption of foods enriched in fat and sugar. It is well-known that, in all species, the cortisol response to stress or adrenocorticotropin is highly variable. It has now emerged that cortisol responsiveness is an important determinant in the metabolic sequelae to stress. Sheep that are characterized as high-cortisol responders (HRs) have greater propensity to weight gain and obesity than low-cortisol responders (LRs). This difference in susceptibility to become obese is associated with a distinct metabolic, neuroendocrine, and behavioral phenotype. In women and ewes, HR individuals eat more in response to stress than LR. Furthermore, HR sheep have impaired melanocortin signaling and reduced skeletal muscle thermogenesis. High-cortisol responder sheep exhibit reactive coping strategies, whereas LRs exhibit proactive coping strategies. This complex set of traits leads to increased food intake and reduced energy expenditure in HR and thus, predisposition to obesity. We predict that cortisol responsiveness may be used as a marker to identify individuals who are at risk of weight gain and subsequent obesity.
Collapse
Affiliation(s)
| | - T K Lee
- Department of Physiology, Monash University, VIC 3800, Australia
| | - I J Clarke
- Department of Physiology, Monash University, VIC 3800, Australia
| | - B A Henry
- Department of Physiology, Monash University, VIC 3800, Australia.
| |
Collapse
|
21
|
Blanquer-Rosselló MM, Santandreu FM, Oliver J, Roca P, Valle A. Leptin Modulates Mitochondrial Function, Dynamics and Biogenesis in MCF-7 Cells. J Cell Biochem 2016; 116:2039-48. [PMID: 25752935 DOI: 10.1002/jcb.25158] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/03/2015] [Indexed: 01/07/2023]
Abstract
The adipokine leptin, known for its key role in the control of energy metabolism, has been shown to be involved in both normal and tumoral mammary growth. One of the hallmarks of cancer is an alteration of tumor metabolism since cancerous cells must rewire metabolism to satisfy the demands of growth and proliferation. Considering the sensibility of breast cancer cells to leptin, the objective of this study was to explore the effects of this adipokine on their metabolism. To this aim, we treated the MCF-7 breast cancer cell line with 50 ng/mL leptin and analyzed several features related to cellular and mitochondrial metabolism. As a result, leptin increased cell proliferation, shifted ATP production from glycolysis to mitochondria and decreased the levels of the glycolytic end-product lactate. We observed an improvement in ADP-dependent oxygen consumption and an amelioration of oxidative stress without changes in total mitochondrial mass or specific oxidative phosphorylation (OXPHOS) complexes. Furthermore, RT-PCR and western blot showed an up-regulation for genes and proteins related to biogenesis and mitochondrial dynamics. This expression signature, together with an increased mitophagy observed by confocal microscopy suggests that leptin may improve mitochondrial quality and function. Taken together, our results propose that leptin may improve bioenergetic efficiency by avoiding the production of reactive oxygen species (ROS) and conferring benefits for growth and survival of MCF-7 breast cancer cells.
Collapse
Affiliation(s)
- M Mar Blanquer-Rosselló
- Grupo Multidisciplinar de Oncología Traslacional, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Palma de Mallorca, Illes Balears, Spain.,Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto Salud Carlos III, Madrid, Spain
| | - Francisca M Santandreu
- Grupo Multidisciplinar de Oncología Traslacional, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Palma de Mallorca, Illes Balears, Spain.,Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto Salud Carlos III, Madrid, Spain
| | | | - Pilar Roca
- Grupo Multidisciplinar de Oncología Traslacional, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Palma de Mallorca, Illes Balears, Spain.,Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto Salud Carlos III, Madrid, Spain
| | - Adamo Valle
- Grupo Multidisciplinar de Oncología Traslacional, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Palma de Mallorca, Illes Balears, Spain.,Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto Salud Carlos III, Madrid, Spain
| |
Collapse
|
22
|
Henry BA, Loughnan R, Hickford J, Young IR, St John JC, Clarke I. Differences in mitochondrial DNA inheritance and function align with body conformation in genetically lean and fat sheep. J Anim Sci 2016; 93:2083-93. [PMID: 26020304 DOI: 10.2527/jas.2014-8764] [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: 11/13/2022] Open
Abstract
Body weight and adiposity are determined by the balance between energy intake, energy expenditure, and nutrient deposition. We have identified differences in appetite-regulating peptides in sheep selectively bred to be either lean or fat, wherein gene expression for orexin and melanin-concentrating hormone are elevated in the lean group. Despite this, the underlying mechanisms leading to differences in body composition in the lean and fat lines remains unknown. We measured postprandial temperature in adipose tissue and muscle to ascertain whether a difference in thermogenesis is associated with the difference in body composition in genetically lean (n = 8) and fat (n = 12) ewes. Body weight was higher (P < 0.01) but percent fat mass was lower (P < 0.001) in the lean group. The percent lean mass was similar in lean and fat groups. Animals received intracerebroventricular cannulae and temperature probes implanted into the retroperitoneal fat and the hind-limb skeletal muscle (vastus lateralis). Animals were meal fed (1100-1600 h) to entrain postprandial thermogenesis. Food intake was similar between lean and fat animals. Postprandial thermogenesis was greater (P < 0.05) in the retroperitoneal adipose tissue of lean animals but not in skeletal muscle. Intracerebroventricular infusion of leptin reduced (P< 0.05) food intake by an equal extent in both groups. Postprandial expression of UCP1 mRNA was greater (P < 0.05) in retroperitoneal fat of lean animals, with similar UCP3 expression in skeletal muscle. Mitochondrial genome sequencing indicated haplotypic clustering in lean and fat animals within both the encoding and nonencoding regions. This demonstrates that differences in body composition may be underpinned by differences in thermogenesis, specifically within adipose tissue. Furthermore, thermogenic differences may be associated with specific mitochondrial DNA haplotypes, suggesting a strong genetic component inherited through the maternal lineage.
Collapse
|
23
|
Normoyle KP, Kim M, Farahvar A, Llano D, Jackson K, Wang H. The emerging neuroprotective role of mitochondrial uncoupling protein-2 in traumatic brain injury. Transl Neurosci 2015; 6:179-186. [PMID: 28123803 PMCID: PMC4936626 DOI: 10.1515/tnsci-2015-0019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 07/20/2015] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) is a multifaceted disease with intrinsically complex heterogeneity and remains a significant clinical challenge to manage. TBI model systems have demonstrated many mechanisms that contribute to brain parenchymal cell death, including glutamate and calcium toxicity, oxidative stress, inflammation, and mitochondrial dysfunction. Mitochondria are critically regulated by uncoupling proteins (UCP), which allow protons to leak back into the matrix and thus reduce the mitochondrial membrane potential by dissipating the proton motive force. This uncoupling of oxidative phosphorylation from adenosine triphosphate (ATP) synthesis is potentially critical for protection against cellular injury as a result of TBI and stroke. A greater understanding of the underlying mechanism or mechanisms by which uncoupling protein-2 (UCP2) functions to maintain or optimize mitochondrial function, and the conditions which precipitate the failure of these mechanisms, would inform future research and treatment strategies. We posit that UCP2-mediated function underlies the physiological response to neuronal stress associated with traumatic and ischemic injury and that clinical development of UCP2-targeted treatment would significantly impact these patient populations. With a focus on clinical relevance in TBI, we synthesize current knowledge concerning UCP2 and its potential neuroprotective role and apply this body of knowledge to current and potential treatment modalities.
Collapse
Affiliation(s)
- Kieran P Normoyle
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Child Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Miri Kim
- College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Arash Farahvar
- Department of Neurosurgery, Carle Foundation Hospital, Urbana, IL, USA
| | - Daniel Llano
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Neurology, Carle Foundation Hospital, Urbana, IL, USA; The Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kevin Jackson
- The Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Thermal Neuroscience Laboratory (TNL), Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Huan Wang
- Department of Neurology, Carle Foundation Hospital, Urbana, IL, USA; Thermal Neuroscience Laboratory (TNL), Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| |
Collapse
|
24
|
Hewagalamulage SD, Clarke IJ, Young IR, Rao A, Henry BA. High cortisol response to adrenocorticotrophic hormone identifies ewes with reduced melanocortin signalling and increased propensity to obesity. J Neuroendocrinol 2015; 27:44-56. [PMID: 25315658 DOI: 10.1111/jne.12233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 09/16/2014] [Accepted: 10/11/2014] [Indexed: 12/26/2022]
Abstract
We have identified female sheep that have either high (HR) or low (LR) cortisol responses to adrenocorticotrophin. On a high-energy diet, HR have greater propensity to weight gain and obesity, although the underlying mechanisms remain to be determined. Hypothalamic appetite-regulating peptides (ARP) exert reciprocal effects on food intake and energy expenditure. We aimed to quantify the expression and function of ARP in LR and HR ewes (n = 4 per group). Gene expression for neuropeptide Y (NPY), agouti-related peptide (AgRP) pro-opiomelanocortin (POMC), melanin-concentrating hormone (MCH), orexin and the melanocortin receptors (MC3R and MC4R) was measured by in situ hybridisation. Expression of NPY, AgRP and POMC was similar in HR and LR, although expression of orexin, MCH, MC3R and MC4R was higher (P < 0.05) in LR. Intracerebroventricular infusions of a low dose (50 μg/h) of NPY, α-melanocyte-stimulating hormone (αMSH), orexin and MCH were performed between 10.00 h and 16.00 h in meal-fed ewes (n = 6-7 per group). Skeletal muscle and retroperitoneal (RP) fat temperatures were recorded using dataloggers. Post-prandial thermogenesis in muscle was higher (P < 0.05) in LR. There was little effect of ARP infusion on muscle or fat temperature in either group. Infusion of these doses of NPY, MCH or orexin did not stimulate food intake in meal-fed ewes, although αMSH reduced (P < 0.01) food intake in LR only. Using 24-h ARP infusions with ad lib. feeding, NPY increased (P < 0.001) food intake in both groups but αMSH was only effective in LR (P < 0.05). In summary, we show that HR are resistant to the satiety effects of αMSH and this coincides with a reduced expression of both the MC3R and MC4R in the paraventricular nucleus of the hypothalamus. We conclude that an increased propensity to obesity in HR female sheep is associated with reduced melanocortin signalling.
Collapse
|
25
|
Lee TK, Lee C, Bischof R, Lambert GW, Clarke IJ, Henry BA. Stress-induced behavioral and metabolic adaptations lead to an obesity-prone phenotype in ewes with elevated cortisol responses. Psychoneuroendocrinology 2014; 47:166-77. [PMID: 25001966 DOI: 10.1016/j.psyneuen.2014.05.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/26/2014] [Accepted: 05/21/2014] [Indexed: 11/17/2022]
Abstract
The underlying cause of predisposition to obesity is complex but one marker is cortisol responsiveness. Selection of sheep for high (HR) or low (LR) cortisol responses to adrenocorticotropin shows that HR are more likely to become obese. Increased propensity to obesity is associated with reduced skeletal muscle thermogenesis. We sought to determine whether metabolic or behavioral responses to stress also contribute to altered propensity to obesity in LR and HR. Animals (n=5-10/group) were exposed to 3 stressors and we measured food intake and thermogenesis (recorded with dataloggers implanted into muscle). Stressors were hypoglycaemia (0.125 units/kg insulin, IV), a barking dog and immune challenge (200 ng/kg lipopolysaccharide--LPS, IV). LR animals showed a greater catabolic state in response to both immune and psychosocial stressors. LPS reduced (P<0.01) food intake in both groups but LR showed a greater (P<0.05) reduction in food intake and a more substantial (P<0.05) rise in muscle temperature. Introduction of the barking dog reduced (P<0.05) food intake in LR only. These metabolic differences coincided with differences in cortisol responsiveness, where HR animals had increased (P<0.05) cortisol in response to both immune and psychosocial stressors. We also assessed behavior in the following paradigms: 1, isolation in the open field test; 2, response to a human intruder; and 3, food competition. LR had greater (P<0.05) activity, reduced fearfulness and displayed a proactive coping style of behavior. Thus we demonstrate that high cortisol responsiveness identifies animals with stress-induced metabolic and behavioral traits that may contribute to susceptibility to obesity.
Collapse
Affiliation(s)
- T Kevin Lee
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Caroline Lee
- CSIRO Animal, Food and Health Sciences, Armidale, NSW 2350, Australia
| | - Robert Bischof
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Gavin W Lambert
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia; Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Iain J Clarke
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Belinda A Henry
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia.
| |
Collapse
|
26
|
Chausse B, Solon C, Caldeira da Silva CC, Masselli Dos Reis IG, Manchado-Gobatto FB, Gobatto CA, Velloso LA, Kowaltowski AJ. Intermittent fasting induces hypothalamic modifications resulting in low feeding efficiency, low body mass and overeating. Endocrinology 2014; 155:2456-66. [PMID: 24797627 DOI: 10.1210/en.2013-2057] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intermittent fasting (IF) is an often-used intervention to decrease body mass. In male Sprague-Dawley rats, 24 hour cycles of IF result in light caloric restriction, reduced body mass gain, and significant decreases in the efficiency of energy conversion. Here, we study the metabolic effects of IF in order to uncover mechanisms involved in this lower energy conversion efficiency. After 3 weeks, IF animals displayed overeating during fed periods and lower body mass, accompanied by alterations in energy-related tissue mass. The lower efficiency of energy use was not due to uncoupling of muscle mitochondria. Enhanced lipid oxidation was observed during fasting days, whereas fed days were accompanied by higher metabolic rates. Furthermore, an increased expression of orexigenic neurotransmitters AGRP and NPY in the hypothalamus of IF animals was found, even on feeding days, which could explain the overeating pattern. Together, these effects provide a mechanistic explanation for the lower efficiency of energy conversion observed. Overall, we find that IF promotes changes in hypothalamic function that explain differences in body mass and caloric intake.
Collapse
Affiliation(s)
- Bruno Chausse
- Departamento de Bioquímica (B.C., C.C.C., A.J.K.), Instituto de Química, Universidade de São Paulo, 05508-000 Brazil; Faculdade de Ciências Médicas (C.S., L.A.V.), Universidade Estadual de Campinas, 13083-970 Brazil; Faculdade de Ciências Aplicadas (I.G.M., F.B.M-G., C.A.G.), Universidade Estadual de Campinas, 13084-350 Brazil
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Yau SW, Henry BA, Russo VC, McConell GK, Clarke IJ, Werther GA, Sabin MA. Leptin enhances insulin sensitivity by direct and sympathetic nervous system regulation of muscle IGFBP-2 expression: evidence from nonrodent models. Endocrinology 2014; 155:2133-43. [PMID: 24654786 DOI: 10.1210/en.2013-2099] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leptin is produced from white adipose tissue and acts primarily to regulate energy balance. Obesity is associated with leptin resistance and increased circulating levels of leptin. Leptin has recently been shown to influence levels of IGF binding protein-2 (IGFBP-2), a protein that is reduced in obesity and type 2 diabetes. Overexpression of IGFBP-2 protects against obesity and type 2 diabetes. As such, IGFBP-2 signaling may represent a novel pathway by which leptin regulates insulin sensitivity. We sought to investigate how leptin regulates skeletal muscle IGFBP-2 levels and to assess the impact of this on insulin signaling and glucose uptake. In vitro experiments were undertaken in cultured human skeletal myotubes, whereas in vivo experiments assessed the effect of intracerebroventricular leptin on peripheral skeletal muscle IGFBP-2 expression and insulin sensitivity in sheep. Leptin directly increased IGFBP-2 mRNA and protein in human skeletal muscle through both signal transducer and activator of transcription-3 and phosphatidylinositol 3-kinase signaling, in parallel with enhanced insulin signaling. Silencing IGFBP-2 lowered leptin- and insulin-stimulated protein kinase B phosphorylation and glucose uptake. In in vivo experiments, intracerebroventricular leptin significantly increased hind-limb skeletal muscle IGFBP-2, an effect completely blocked by concurrent peripheral infusion of a β-adrenergic blocking agent. Sheep receiving central leptin showed improvements in glucose tolerance and circulating insulin levels after an iv glucose load. In summary, leptin regulates skeletal muscle IGFBP-2 by both direct peripheral and central (via the sympathetic nervous system) mechanisms, and these likely impact on peripheral insulin sensitivity and glucose metabolism.
Collapse
Affiliation(s)
- Steven W Yau
- Centre for Hormone Research (S.W.Y., V.C.R., G.A.W., M.A.S.), Murdoch Childrens Research Institute and Royal Children's Hospital, and Department of Paediatrics (S.W.Y., V.C.R., G.A.W., M.A.S.), University of Melbourne, Melbourne, Victoria 3052, Australia; Department of Physiology (S.W.Y., B.A.H., I.J.C., M.A.S.), Monash University, Melbourne, Victoria 3800, Australia; and Institute of Sport, Exercise and Active Living and the College of Health and Biomedicine (G.K.M.), Victoria University, Melbourne, Victoria 3011, Australia
| | | | | | | | | | | | | |
Collapse
|
28
|
Clarke IJ. Interface between metabolic balance and reproduction in ruminants: focus on the hypothalamus and pituitary. Horm Behav 2014; 66:15-40. [PMID: 24568750 DOI: 10.1016/j.yhbeh.2014.02.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 01/24/2023]
Abstract
This article is part of a Special Issue "Energy Balance". The interface between metabolic regulators and the reproductive system is reviewed with special reference to the sheep. Even though sheep are ruminants with particular metabolic characteristics, there is a broad consensus across species in the way that the reproductive system is influenced by metabolic state. An update on the neuroendocrinology of reproduction indicates the need to account for the way that kisspeptin provides major drive to gonadotropin releasing hormone (GnRH) neurons and also mediates the feedback effects of gonadal steroids. The way that kisspeptin function is influenced by appetite regulating peptides (ARP) is considered. Another newly recognised factor is gonadotropin inhibitory hormone (GnIH), which has a dual function in that it suppresses reproductive function whilst also acting as an orexigen. Our understanding of the regulation of food intake and energy expenditure has expanded exponentially in the last 3 decades and historical perspective is provided. The function of the regulatory factors and the hypothalamic cellular systems involved is reviewed with special reference to the sheep. Less is known of these systems in the cow, especially the dairy cow, in which a major fertility issue has emerged in parallel with selection for increased milk production. Other endocrine systems--the hypothalamo-pituitary-adrenal axis, the growth hormone (GH) axis and the thyroid hormones--are influenced by metabolic state and are relevant to the interface between metabolic function and reproduction. Special consideration is given to issues such as season and lactation, where the relationship between metabolic hormones and reproductive function is altered.
Collapse
Affiliation(s)
- Iain J Clarke
- Monash University, Department of Physiology, Wellington Road, Clayton 3168, Australia.
| |
Collapse
|
29
|
DiGiacomo K, Leury BJ, Dunshea FR. Potential nutritional strategies for the amelioration or prevention of high rigor temperature in cattle – a review. ANIMAL PRODUCTION SCIENCE 2014. [DOI: 10.1071/an13303] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Environmental conditions influence animal production from an animal performance perspective and at the carcass level post-slaughter. High rigor temperature occurs when the animal is hyperthermic pre-slaughter, and this leads to tougher meat. Hyperthermia can result from increased environmental temperature, exercise, stress or a combination of these factors. Consumer satisfaction with beef meat is influenced by the visual and sensory traits of the product when raw and cooked, with beef consumers commonly selecting tenderness of the product as the most important quality trait. High rigor temperature leads to a reduction in carcass and eating quality. This review examines some possible metabolic causes of hyperthermia, with focus on the importance of adipose tissue metabolism and the roles of insulin and leptin. Potential strategies for the amelioration or prevention of high rigor temperature are offered, including the use of dietary supplements such as betaine and chromium, anti-diabetic agents such as thiazolidinediones, vitamin D, and magnesium (Mg) to provide stress relief.
Collapse
|
30
|
Lee TK, Clarke IJ, John JS, Young IR, Leury BL, Rao A, Andrews ZB, Henry BA. High cortisol responses identify propensity for obesity that is linked to thermogenesis in skeletal muscle. FASEB J 2013; 28:35-44. [DOI: 10.1096/fj.13-238345] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- T. Kevin Lee
- Department of PhysiologyMonash UniversityClaytonVictoriaAustralia
| | - Iain J. Clarke
- Department of PhysiologyMonash UniversityClaytonVictoriaAustralia
| | - Justin St. John
- Monash Institute of Medical ResearchMonash Medical CentreClaytonVictoriaAustralia
| | - I. Ross Young
- Department of PhysiologyMonash UniversityClaytonVictoriaAustralia
| | - Brian L. Leury
- Melbourne School of Land and EnvironmentUniversity of MelbourneMelbourneVictoriaAustralia
| | - Alexandra Rao
- Department of PhysiologyMonash UniversityClaytonVictoriaAustralia
| | - Zane B. Andrews
- Department of PhysiologyMonash UniversityClaytonVictoriaAustralia
| | - Belinda A. Henry
- Department of PhysiologyMonash UniversityClaytonVictoriaAustralia
| |
Collapse
|
31
|
Clarke SD, Clarke IJ, Rao A, Evans RG, Henry BA. Differential effects of acute and chronic estrogen treatment on thermogenic and metabolic pathways in ovariectomized sheep. Endocrinology 2013. [PMID: 23183185 DOI: 10.1210/en.2012-1758] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Estrogen is protective against weight gain, but the underlying mechanisms are not fully elucidated. We sought to characterize the effects of estrogen on energy expenditure in skeletal muscle and adipose tissue in ovariectomized sheep. Temperature probes were implanted into sc (gluteal) and visceral (retroperitoneal) fat depots and skeletal muscle of the hind limb (vastus lateralis). Food was available from 1100-1600 h to entrain postprandial thermogenesis. We characterized the effects of single (50 μg estradiol benzoate, im) and repeated (25 μg estradiol-17β, iv) injections as well as chronic (3 × 3 cm estradiol-17β implants for 7 d) treatment on heat production. A single injection of estrogen increased heat production in visceral fat and skeletal muscle, without an effect on food intake. Increased heat production in skeletal muscle was sustained by repeated estradiol-17β injections. On the other hand, continuous treatment reduced food intake but had no effect on thermogenesis. To determine possible mechanisms that underpin estradiol-17β-induced heat production, we measured femoral artery blood flow, the expression of uncoupling protein (UCP) mRNA and the phosphorylation of AMP-activated protein kinase and Akt in fat and muscle. There was little effect of either single or repeated injections of estradiol-17β on the expression of UCP1, -2, or -3 mRNA in visceral fat or skeletal muscle. Acute injection of estradiol-17β increased the phosphorylation of AMP-activated protein kinase and Akt in muscle only. Estradiol-17β treatment did not alter femoral artery blood flow. Thus, the stimulatory effect of estradiol-17β on thermogenesis in female sheep is dependent upon a pulsatile pattern of treatment and not constant continuous exposure.
Collapse
Affiliation(s)
- Scott D Clarke
- Research Fellow, Monash University, Physiology, Building 13F, Wellington Road, Clayton, Victoria 3168, Australia
| | | | | | | | | |
Collapse
|
32
|
Clarke SD, Lee K, Andrews ZB, Bischof R, Fahri F, Evans RG, Clarke IJ, Henry BA. Postprandial heat production in skeletal muscle is associated with altered mitochondrial function and altered futile calcium cycling. Am J Physiol Regul Integr Comp Physiol 2012; 303:R1071-9. [DOI: 10.1152/ajpregu.00036.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study aimed to determine whether postprandial temperature excursions in skeletal muscle are consistent with thermogenesis or altered blood flow. Temperature probes were implanted into the vastus lateralis muscle of ovariectomized ewes, and blood flow was assessed using laser-Doppler flowmetry (tissue flow) and transit-time ultrasound flowmetry (femoral artery flow). The animals were program-fed between 1100 and 1600, and temperature and blood flow were measured during intravenous administration of either isoprenaline or phenylephrine and during feeding and meal anticipation. In addition, muscle biopsies were collected prefeeding and postfeeding to measure uncoupling protein (UCP) expression and mitochondrial function, as well as indices of calcium cycling (ryanodine 1 receptor: RyR1 and sarcoendoplasmic calcium-dependent ATPases SERCA1/ SERCA2a). Isoprenaline increased femoral artery blood flow, whereas phenylephrine reduced blood flow. At high doses only, isoprenaline treatment increased heat production in muscle. Phenylephrine treatment did not alter muscle temperature. Meal anticipation was evoked in fasted animals (previously program-fed) that were housed beside animals that were fed. Increases in muscle temperature were elicited by feeding and meal anticipation, without changes in blood flow during either paradigm. Analyses of respiration in isolated mitochondria indicated that the postprandial increase in heat production was associated with an increase in state 4 respiration, without increased UCP1, UCP2, or UCP3 expression. Feeding increased the expression of RyR1 and SERCA2a. We conclude that excursions in muscle temperature may occur independent of blood flow, suggesting that postprandial heat production is driven by altered mitochondrial function and changes in calcium cycling.
Collapse
Affiliation(s)
- Scott D. Clarke
- Department of Physiology, Monash University, Victoria, Australia; and
| | - Kevin Lee
- Department of Physiology, Monash University, Victoria, Australia; and
| | - Zane B. Andrews
- Department of Physiology, Monash University, Victoria, Australia; and
| | - Robert Bischof
- Department of Physiology, Monash University, Victoria, Australia; and
| | - Fahri Fahri
- School of Land and Environment, University of Melbourne, Victoria, Australia
| | - Roger G. Evans
- Department of Physiology, Monash University, Victoria, Australia; and
| | - Iain J. Clarke
- Department of Physiology, Monash University, Victoria, Australia; and
| | - Belinda A. Henry
- Department of Physiology, Monash University, Victoria, Australia; and
| |
Collapse
|
33
|
Holness MJ, Sugden PH, Silvestre MF, Sugden MC. Actions and interactions of AMPK with insulin, the peroxisomal-proliferator activated receptors and sirtuins. Expert Rev Endocrinol Metab 2012; 7:191-208. [PMID: 30764011 DOI: 10.1586/eem.12.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AMP-activated protein kinase (AMPK) activity responds to a requirement to increase cellular ATP production and/or to conserve available ATP. AMPK is therefore central to the mechanisms of adjustment to fluctuating energy demand or metabolic substrate supply. AMPK has important actions in several insulin-responsive tissues, as well as in the pancreatic β cell, through which it can modulate glycemic control, insulin action and metabolic substrate selection and disposal. We review recent novel findings elucidating the mechanisms by which AMPK activation can correct impaired insulin action. However, we also emphasize not only the similarities, but also the differences in the actions of insulin and AMPK. We focus on metabolic interfaces between AMPK, peroxisomal proliferator-activated receptors, sirtuins and mTORC.
Collapse
Affiliation(s)
- Mark J Holness
- a Centre for Diabetes, Blizard Institute, Barts and the London School of Medicine and Dentistry, 4 Newark Street, Whitechapel, London, E1 2AT, UK.
| | - Peter H Sugden
- b Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, RG6 6BX, UK
| | - Marta Fp Silvestre
- a Centre for Diabetes, Blizard Institute, Barts and the London School of Medicine and Dentistry, 4 Newark Street, Whitechapel, London, E1 2AT, UK.
| | - Mary C Sugden
- a Centre for Diabetes, Blizard Institute, Barts and the London School of Medicine and Dentistry, 4 Newark Street, Whitechapel, London, E1 2AT, UK.
| |
Collapse
|
34
|
Clarke SD, Clarke IJ, Rao A, Cowley MA, Henry BA. Sex differences in the metabolic effects of testosterone in sheep. Endocrinology 2012; 153:123-31. [PMID: 22128020 DOI: 10.1210/en.2011-1634] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adiposity is regulated in a sexually divergent manner. This is partly due to sex steroids, but the differential effects of androgens in males and females are unclear. We investigated effects of testosterone on energy balance in castrated male (n = 6) and female sheep (n = 4), which received 3 × 200 mg testosterone implants for 2 wk or blank implants (controls). Temperature probes were implanted into retroperitoneal fat and skeletal muscle. Blood samples were taken to measure metabolites and insulin. In males, muscle and fat biopsies were collected to measure uncoupling protein (UCP) mRNA and phosphorylation of AMP-activated protein kinase and Akt. Testosterone did not change food intake in either sex. Temperature in muscle was higher in males than females, and testosterone reduced heat production in males only. In fat, however, temperature was higher in the castrate males compared with females, and there was no effect of testosterone treatment in either sex. Preprandial glucose levels were lower, but nonesterified fatty acids were higher in females compared with males, irrespective of testosterone. In males, the onset of feeding increased UCP1 and UCP3 mRNA levels in skeletal muscle, without an effect of testosterone. During feeding, testosterone reduced glucose levels in males only but did not alter the phosphorylation of AMP-activated protein kinase or Akt in muscle. Thus, testosterone maintains lower muscle and fat temperatures in males but not females. The mechanism underlying this sex-specific effect of testosterone is unknown but may be due to sexual differentiation of the brain centers controlling energy expenditure.
Collapse
Affiliation(s)
- Scott D Clarke
- Department of Physiology, Monash University, Wellington Road, Clayton, Victoria 3168, Australia
| | | | | | | | | |
Collapse
|
35
|
Baldwin KM, Joanisse DR, Haddad F, Goldsmith RL, Gallagher D, Pavlovich KH, Shamoon EL, Leibel RL, Rosenbaum M. Effects of weight loss and leptin on skeletal muscle in human subjects. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1259-66. [PMID: 21917907 PMCID: PMC3213951 DOI: 10.1152/ajpregu.00397.2011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 09/06/2011] [Indexed: 01/12/2023]
Abstract
Maintenance of a 10% or greater reduced body weight results in decreases in the energy cost of low levels of physical activity beyond those attributable to the altered body weight. These changes in nonresting energy expenditure are due mainly to increased skeletal muscle work efficiency following weight loss and are reversed by the administration of the adipocyte-derived hormone leptin. We have also shown previously that the maintenance of a reduced weight is accompanied by a decrease in ratio of glycolytic (phosphofructokinase) to oxidative (cytochrome c oxidase) activity in vastus lateralis muscle that would suggest an increase in the relative expression of the myosin heavy chain I (MHC I) isoform. We performed analyses of vastus lateralis muscle needle biopsy samples to determine whether maintenance of an altered body weight was associated with changes in skeletal muscle metabolic properties as well as mRNA expression of different isoforms of the MHC and sarcoplasmic endoplasmic reticular Ca(2+)-dependent ATPase (SERCA) in subjects studied before weight loss and then again after losing 10% of their initial weight and receiving twice daily injections of either placebo or replacement leptin in a single blind crossover design. We found that the maintenance of a reduced body weight was associated with significant increases in the relative gene expression of MHC I mRNA that was reversed by the administration of leptin as well as an increase in the expression of SERCA2 that was not significantly affected by leptin. Leptin administration also resulted in a significant increase in the expression of the less MHC IIx isoform compared with subjects receiving placebo. These findings are consistent with the leptin-reversible increase in skeletal muscle chemomechanical work efficiency and decrease in the ratio of glycolytic/oxidative enzyme activities observed in subjects following dietary weight loss.
Collapse
Affiliation(s)
- Kenneth M. Baldwin
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California
| | | | - Fadia Haddad
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California
| | - Rochelle L. Goldsmith
- Division of Exercise Physiology; Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, New York
| | - Dympna Gallagher
- Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, New York; and
| | - Katherine H. Pavlovich
- Division of Molecular Genetics, Departments of Pediatrics and Medicine, Columbia University, New York, New York
| | - Elisabeth L. Shamoon
- Division of Molecular Genetics, Departments of Pediatrics and Medicine, Columbia University, New York, New York
| | - Rudolph L. Leibel
- Division of Molecular Genetics, Departments of Pediatrics and Medicine, Columbia University, New York, New York
| | - Michael Rosenbaum
- Division of Molecular Genetics, Departments of Pediatrics and Medicine, Columbia University, New York, New York
| |
Collapse
|