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Abstract
Interactions between the brain and distinct adipose depots have a key role in maintaining energy balance, thereby promoting survival in response to metabolic challenges such as cold exposure and starvation. Recently, there has been renewed interest in the specific central neuronal circuits that regulate adipose depots. Here, we review anatomical, genetic and pharmacological studies on the neural regulation of adipose function, including lipolysis, non-shivering thermogenesis, browning and leptin secretion. In particular, we emphasize the role of leptin-sensitive neurons and the sympathetic nervous system in modulating the activity of brown, white and beige adipose tissues. We provide an overview of advances in the understanding of the heterogeneity of the brain regulation of adipose tissues and offer a perspective on the challenges and paradoxes that the community is facing regarding the actions of leptin on this system.
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Affiliation(s)
- Alexandre Caron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Syann Lee
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K. Elmquist
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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102
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Pulong WP, Ushikai M, Arimura E, Abe M, Kawaguchi H, Horiuchi M. Food Intake and Core Body Temperature of Pups and Adults in a db Mouse Line Deficient in the Long Form of the Leptin Receptor without Misty Mutation. J Diabetes Res 2018; 2018:9670871. [PMID: 30622972 PMCID: PMC6304817 DOI: 10.1155/2018/9670871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/22/2018] [Indexed: 12/04/2022] Open
Abstract
Different involvement of leptin signaling in food intake (FI) and body temperature (BT) in pups and adults has been suggested. However, the leptin receptor (Lepr) long-form-deficient (db) mouse line has not been fully examined in pups. In the most available db mouse line, wild-type (WT) mice have a mutation in the dedicator of cytokinesis 7 gene, named misty, which was recently revealed to be involved in neuronal development. Therefore, we established a line of db mice without the misty mutation using natural mating. Adult (8 weeks of age) homozygous db/db mice displayed significantly higher core body weight (BW) and FI and significantly lower core BT than WT mice. However, postnatal (2 weeks of age) db/db mice displayed similar BW and milk intake and significantly lower core BT than WT mice. Correspondingly, adult and postnatal db/db mice exhibited altered mRNA levels of hypothalamic orexigenic and anorexigenic peptide in adults but not in pups. Additionally, db/db mice displayed significantly lower mRNA levels of brown adipose tissue uncoupling protein 1 at both ages. In conclusion, the db mouse line without the misty mutation clearly showed the different involvements of the Lepr long form in FI and BT in pups and adults.
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Affiliation(s)
- Wijang Pralampita Pulong
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima 890-8544, Japan
| | - Miharu Ushikai
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima 890-8544, Japan
| | - Emi Arimura
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima 890-8544, Japan
- Department of Life and Environmental Science, Kagoshima Prefectural College, Kagoshima City, Kagoshima 890-0005, Japan
| | - Masaharu Abe
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima 890-8544, Japan
| | - Hiroaki Kawaguchi
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima 890-8544, Japan
| | - Masahisa Horiuchi
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Kagoshima 890-8544, Japan
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103
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Merlin J, Sato M, Chia LY, Fahey R, Pakzad M, Nowell CJ, Summers RJ, Bengtsson T, Evans BA, Hutchinson DS. Rosiglitazone and a β 3-Adrenoceptor Agonist Are Both Required for Functional Browning of White Adipocytes in Culture. Front Endocrinol (Lausanne) 2018; 9:249. [PMID: 29910772 PMCID: PMC5992408 DOI: 10.3389/fendo.2018.00249] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/02/2018] [Indexed: 01/01/2023] Open
Abstract
The recruitment of brite (or beige) adipocytes has been advocated as a means to combat obesity, due to their ability to phenotypically resemble brown adipocytes (BA). Lineage studies indicate that brite adipocytes are formed by differentiation of precursor cells or by direct conversion of existing white adipocytes, depending on the adipose depot examined. We have systematically compared the gene expression profile and a functional output (oxygen consumption) in mouse adipocytes cultured from two contrasting depots, namely interscapular brown adipose tissue, and inguinal white adipose tissue (iWAT), following treatment with a known browning agent, the peroxisome proliferator-activated receptor (PPARγ) activator rosiglitazone. Prototypical BA readily express uncoupling protein (UCP)1, and upstream regulators including the β3-adrenoceptor and transcription factors involved in energy homeostasis. Adipocytes from inguinal WAT display maximal UCP1 expression and mitochondrial uncoupling only when treated with a combination of the PPARγ activator rosiglitazone and a β3-adrenoceptor agonist. In conclusion, brite adipocytes are fully activated only when a browning agent (rosiglitazone) and a thermogenic agent (β3-adrenoceptor agonist) are added in combination. The presence of rosiglitazone throughout the 7-day culture period partially masks the effects of β3-adrenoceptor signaling in inguinal white adipocyte cultures, whereas including rosiglitazone only for the first 3 days promotes robust β3-adrenoceptor expression and provides an improved window for detection of β3-adrenoceptor responses.
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Affiliation(s)
- Jon Merlin
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Richard Fahey
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Mohsen Pakzad
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Cameron J. Nowell
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Roger J. Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Bronwyn A. Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Dana S. Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Pharmacology, Monash University, Clayton, VIC, Australia
- *Correspondence: Dana S. Hutchinson,
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104
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Fruhwürth S, Vogel H, Schürmann A, Williams KJ. Novel Insights into How Overnutrition Disrupts the Hypothalamic Actions of Leptin. Front Endocrinol (Lausanne) 2018; 9:89. [PMID: 29632515 PMCID: PMC5879088 DOI: 10.3389/fendo.2018.00089] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 02/23/2018] [Indexed: 12/17/2022] Open
Abstract
Obesity has become a worldwide health problem, but we still do not understand the molecular mechanisms that contribute to overeating and low expenditure of energy. Leptin has emerged as a major regulator of energy balance through its actions in the hypothalamus. Importantly, obese people exhibit high circulating levels of leptin, yet the hypothalamus no longer responds normally to this hormone to suppress appetite or to increase energy expenditure. Several well-known hypotheses have been proposed to explain impaired central responsiveness to the effects of leptin in obesity, including defective transit across the blood-brain barrier at the arcuate nucleus, hypothalamic endoplasmic reticulum stress, maladaptive sterile inflammation in the hypothalamus, and overexpression of molecules that may inhibit leptin signaling. We also discuss a new explanation that is based on our group's recent discovery of a signaling pathway that we named "NSAPP" after its five main protein components. The NSAPP pathway consists of an oxide transport chain that causes a transient, targeted burst in intracellular hydrogen peroxide (H2O2) to inactivate redox-sensitive members of the protein tyrosine phosphatase gene family. The NSAPP oxide transport chain is required for full activation of canonical leptin signaling in neurons but fails to function normally in states of overnutrition. Remarkably, leptin and insulin both require the NSAPP oxide transport chain, suggesting that a defect in this pathway could explain simultaneous resistance to the appetite-suppressing effects of both hormones in obesity.
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Affiliation(s)
- Stefanie Fruhwürth
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Heike Vogel
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Annette Schürmann
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Kevin Jon Williams
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Medicine, Section of Endocrinology, Diabetes, and Metabolism, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- *Correspondence: Kevin Jon Williams,
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105
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Morrison SF. Efferent neural pathways for the control of brown adipose tissue thermogenesis and shivering. HANDBOOK OF CLINICAL NEUROLOGY 2018; 156:281-303. [PMID: 30454595 DOI: 10.1016/b978-0-444-63912-7.00017-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The fundamental central neural circuits for thermoregulation orchestrate behavioral and autonomic repertoires that maintain body core temperature during thermal challenges that arise from either the ambient or the internal environment. This review summarizes our understanding of the neural pathways within the fundamental thermoregulatory reflex circuitry that comprise the efferent (i.e., beyond thermosensory) control of brown adipose tissue (BAT) and shivering thermogenesis: the motor neuron systems consisting of the BAT sympathetic preganglionic neurons and BAT sympathetic ganglion cells, and the alpha- and gamma-motoneurons; the premotor neurons in the region of the rostral raphe pallidus, and the thermogenesis-promoting neurons in the dorsomedial hypothalamus/dorsal hypothalamic area. Also included are inputs to, and neurochemical modulators of, these efferent neuronal populations that could influence their activity during thermoregulatory responses. Signals of metabolic status can be particularly significant for the energy-hungry thermoeffectors for heat production.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States.
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106
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Abstract
A multi-dimensional strategy to tackle the global obesity epidemic requires an in-depth understanding of the mechanisms that underlie this complex condition. Much of the current mechanistic knowledge has arisen from preclinical research performed mostly, but not exclusively, in laboratory mouse and rat strains. These experimental models mimic certain aspects of the human condition and its root causes, particularly the over-consumption of calories and unbalanced diets. As with human obesity, obesity in rodents is the result of complex gene–environment interactions. Here, we review the traditional monogenic models of obesity, their contemporary optogenetic and chemogenetic successors, and the use of dietary manipulations and meal-feeding regimes to recapitulate the complexity of human obesity. We critically appraise the strengths and weaknesses of these different models to explore the underlying mechanisms, including the neural circuits that drive behaviours such as appetite control. We also discuss the use of these models for testing and screening anti-obesity drugs, beneficial bio-actives, and nutritional strategies, with the goal of ultimately translating these findings for the treatment of human obesity. Summary: We review genetic models of obesity, their optogenetic and chemogenetic successors, and the use of dietary manipulations and meal-feeding regimes.
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Affiliation(s)
- Perry Barrett
- The Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Julian G Mercer
- The Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Peter J Morgan
- The Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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107
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Rizwan MZ, Mehlitz S, Grattan DR, Tups A. Temporal and regional onset of leptin resistance in diet-induced obese mice. J Neuroendocrinol 2017; 29. [PMID: 28477438 DOI: 10.1111/jne.12481] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/30/2017] [Accepted: 05/02/2017] [Indexed: 12/01/2022]
Abstract
In common forms of obesity, leptin fails to convey its regulatory effect. This so called "leptin resistance" is not well understood, and solving this puzzle is a key to understanding how obesity develops. In the present study, we investigated the temporal and regional onset of leptin resistance in response to a diet enriched with long-chain saturated fatty acids (high-fat diet; HFD) in mice. Mice were exposed to either a low-fat diet (LFD) or a HFD for 4 hours, 24 hours, 10 days and 28 days. Mice in each group received an i.p. injection of either phosphate-buffered saline or leptin and the number of phosphorylated signal transducer and activator of transcription-3 (pSTAT3) immunoreactive (-IR) cells in the arcuate nucleus (ARC), ventromedial nucleus of the hypothalamus (VMH) and dorsomedial nucleus of the hypothalamus (DMH) was analysed 30 or 120 minutes after treatment. In the ARC, as soon as 24 hours of HFD, the molecular leptin response was reduced by 40% (P≤.01). Compared to at 24 hours, after 10 days, the number of leptin-induced pSTAT3-IR cells was elevated after 120 minutes, suggesting a sustained response and a partial return of leptin sensitivity. After 28 days, leptin failed to induce the number of pSTAT3-IR over control levels, suggesting a markedly reduced sensitivity to leptin. In the VMH after 24 hours, we observed a 50% reduction in leptin-induced pSTAT-3-IR cells, followed by a further decline after 10 days. However, after 28 days, there was a significant increase in pSTAT-3-IR cells (P≤.05), indicating partial recovery of leptin sensitivity. By contrast to these two regions, in the DMH, no loss of leptin sensitivity was observed at any time-point. These findings demonstrate that a loss of sensitivity to leptin occurs rapidly after exposure to HFD in the ARC and VMH but not the DMH. However, there appears to be a biphasic pattern of leptin responsiveness, with a partial return of leptin sensitivity occurring after 10 days in the arcuate nucleus, and after 28 days in the VMH. By 28 days, the response to leptin in the arcuate nucleus was completely lost. These findings suggest that the molecular responses to leptin are altered after high-fat feeding in a time- and region-specific manner.
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Affiliation(s)
- M Z Rizwan
- Department of Physiology, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - S Mehlitz
- Department of Physiology, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - D R Grattan
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - A Tups
- Department of Physiology, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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108
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Morford J, Mauvais-Jarvis F. Sex differences in the effects of androgens acting in the central nervous system on metabolism. DIALOGUES IN CLINICAL NEUROSCIENCE 2017. [PMID: 28179813 PMCID: PMC5286727 DOI: 10.31887/dcns.2016.18.4/fmauvais] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One of the most sexually dimorphic aspects of metabolic regulation is the bidirectional modulation of glucose and energy homeostasis by testosterone in males and females. Testosterone deficiency predisposes men to metabolic dysfunction, with excess adiposity, insulin resistance, and type 2 diabetes, whereas androgen excess predisposes women to insulin resistance, adiposity, and type 2 diabetes. This review discusses how testosterone acts in the central nervous system, and especially the hypothalamus, to promote metabolic homeostasis or dysfunction in a sexually dimorphic manner. We compare the organizational actions of testosterone, which program the hypothalamic control of metabolic homeostasis during development, and the activational actions of testosterone, which affect metabolic function after puberty. We also discuss how the metabolic effect of testosterone is centrally mediated via the androgen receptor.
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Affiliation(s)
- Jamie Morford
- Department of Medicine, Section of Endocrinology and Metabolism, Tulane University Health Sciences Center, School of Medicine, New Orleans, Louisiana, USA
| | - Franck Mauvais-Jarvis
- Department of Medicine, Section of Endocrinology and Metabolism, Tulane University Health Sciences Center, School of Medicine, New Orleans, Louisiana, USA
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109
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Abstract
Brown and beige adipocytes arise from distinct developmental origins. Brown adipose tissue (BAT) develops embryonically from precursors that also give to skeletal muscle. Beige fat develops postnatally and is highly inducible. Beige fat recruitment is mediated by multiple mechanisms, including de novo beige adipogenesis and white-to-brown adipocyte transdifferentiaiton. Beige precursors reside around vasculatures, and proliferate and differentiate into beige adipocytes. PDGFRα+Ebf2+ precursors are restricted to beige lineage cells, while another PDGFRα+ subset gives rise to beige adipocytes, white adipocytes, or fibrogenic cells. White adipocytes can be reprogramed and transdifferentiated into beige adipocytes. Brown and beige adipocytes display many similar properties, including multilocular lipid droplets, dense mitochondria, and expression of UCP1. UCP1-mediated thermogenesis is a hallmark of brown/beige adipocytes, albeit UCP1-independent thermogenesis also occurs. Development, maintenance, and activation of BAT/beige fat are guided by genetic and epigenetic programs. Numerous transcriptional factors and coactivators act coordinately to promote BAT/beige fat thermogenesis. Epigenetic reprograming influences expression of brown/beige adipocyte-selective genes. BAT/beige fat is regulated by neuronal, hormonal, and immune mechanisms. Hypothalamic thermal circuits define the temperature setpoint that guides BAT/beige fat activity. Metabolic hormones, paracrine/autocrine factors, and various immune cells also play a critical role in regulating BAT/beige fat functions. BAT and beige fat defend temperature homeostasis, and regulate body weight and glucose and lipid metabolism. Obesity is associated with brown/beige fat deficiency, and reactivation of brown/beige fat provides metabolic health benefits in some patients. Pharmacological activation of BAT/beige fat may hold promise for combating metabolic diseases. © 2017 American Physiological Society. Compr Physiol 7:1281-1306, 2017.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular and Integrative Physiology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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110
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111
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Glutamatergic Preoptic Area Neurons That Express Leptin Receptors Drive Temperature-Dependent Body Weight Homeostasis. J Neurosci 2017; 36:5034-46. [PMID: 27147656 DOI: 10.1523/jneurosci.0213-16.2016] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/21/2016] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED The preoptic area (POA) regulates body temperature, but is not considered a site for body weight control. A subpopulation of POA neurons express leptin receptors (LepRb(POA) neurons) and modulate reproductive function. However, LepRb(POA) neurons project to sympathetic premotor neurons that control brown adipose tissue (BAT) thermogenesis, suggesting an additional role in energy homeostasis and body weight regulation. We determined the role of LepRb(POA) neurons in energy homeostasis using cre-dependent viral vectors to selectively activate these neurons and analyzed functional outcomes in mice. We show that LepRb(POA) neurons mediate homeostatic adaptations to ambient temperature changes, and their pharmacogenetic activation drives robust suppression of energy expenditure and food intake, which lowers body temperature and body weight. Surprisingly, our data show that hypothermia-inducing LepRb(POA) neurons are glutamatergic, while GABAergic POA neurons, originally thought to mediate warm-induced inhibition of sympathetic premotor neurons, have no effect on energy expenditure. Our data suggest a new view into the neurochemical and functional properties of BAT-related POA circuits and highlight their additional role in modulating food intake and body weight. SIGNIFICANCE STATEMENT Brown adipose tissue (BAT)-induced thermogenesis is a promising therapeutic target to treat obesity and metabolic diseases. The preoptic area (POA) controls body temperature by modulating BAT activity, but its role in body weight homeostasis has not been addressed. LepRb(POA) neurons are BAT-related neurons and we show that they are sufficient to inhibit energy expenditure. We further show that LepRb(POA) neurons modulate food intake and body weight, which is mediated by temperature-dependent homeostatic responses. We further found that LepRb(POA) neurons are stimulatory glutamatergic neurons, contrary to prevalent models, providing a new view on thermoregulatory neural circuits. In summary, our study significantly expands our current understanding of central circuits and mechanisms that modulate energy homeostasis.
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112
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Dodd GT, Andrews ZB, Simonds SE, Michael NJ, DeVeer M, Brüning JC, Spanswick D, Cowley MA, Tiganis T. A Hypothalamic Phosphatase Switch Coordinates Energy Expenditure with Feeding. Cell Metab 2017; 26:375-393.e7. [PMID: 28768176 DOI: 10.1016/j.cmet.2017.07.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 04/13/2017] [Accepted: 07/17/2017] [Indexed: 12/17/2022]
Abstract
Beige adipocytes can interconvert between white and brown-like states and switch between energy storage versus expenditure. Here we report that beige adipocyte plasticity is important for feeding-associated changes in energy expenditure and is coordinated by the hypothalamus and the phosphatase TCPTP. A fasting-induced and glucocorticoid-mediated induction of TCPTP, inhibited insulin signaling in AgRP/NPY neurons, repressed the browning of white fat and decreased energy expenditure. Conversely feeding reduced hypothalamic TCPTP, to increase AgRP/NPY neuronal insulin signaling, white adipose tissue browning and energy expenditure. The feeding-induced repression of hypothalamic TCPTP was defective in obesity. Mice lacking TCPTP in AgRP/NPY neurons were resistant to diet-induced obesity and had increased beige fat activity and energy expenditure. The deletion of hypothalamic TCPTP in obesity restored feeding-induced browning and increased energy expenditure to promote weight loss. Our studies define a hypothalamic switch that coordinates energy expenditure with feeding for the maintenance of energy balance.
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Affiliation(s)
- Garron T Dodd
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Zane B Andrews
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Physiology, Monash University, Victoria 3800, Australia
| | - Stephanie E Simonds
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Physiology, Monash University, Victoria 3800, Australia
| | - Natalie J Michael
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Physiology, Monash University, Victoria 3800, Australia
| | - Michael DeVeer
- Monash Biomedical Imaging, Monash University, Victoria 3168, Australia
| | - Jens C Brüning
- Max Plank Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes, and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; National Center for Diabetes Research (DZD), Ingolstädter Land Str. 1, 85764 Neuherberg, Germany
| | - David Spanswick
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Physiology, Monash University, Victoria 3800, Australia
| | - Michael A Cowley
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Physiology, Monash University, Victoria 3800, Australia
| | - Tony Tiganis
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia; Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia.
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113
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Michael NJ, Simonds SE, van den Top M, Cowley MA, Spanswick D. Mitochondrial uncoupling in the melanocortin system differentially regulates NPY and POMC neurons to promote weight-loss. Mol Metab 2017; 6:1103-1112. [PMID: 29031712 PMCID: PMC5641603 DOI: 10.1016/j.molmet.2017.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/29/2017] [Accepted: 07/05/2017] [Indexed: 12/13/2022] Open
Abstract
Objective The mitochondrial uncoupling agent 2,4-dinitrophenol (DNP), historically used as a treatment for obesity, is known to cross the blood-brain-barrier, but its effects on central neural circuits controlling body weight are largely unknown. As hypothalamic melanocortin neuropeptide Y/agouti-related protein (NPY/AgRP) and pro-opiomelanocortin (POMC) neurons represent key central regulators of food intake and energy expenditure we investigated the effects of DNP on these neurons, food intake and energy expenditure. Method C57BL/6 and melanocortin-4 receptor (MC4R) knock-out mice were administered DNP intracerebroventricularly (ICV) and the metabolic changes were characterized. The specific role of NPY and POMC neurons and the ionic mechanisms mediating the effects of uncoupling were examined with in vitro electrophysiology performed on NPY hrGFP or POMC eGFP mice. Results Here we show DNP-induced differential effects on melanocortin neurons including inhibiting orexigenic NPY and activating anorexigenic POMC neurons through independent ionic mechanisms coupled to mitochondrial function, consistent with an anorexigenic central effect. Central administration of DNP induced weight-loss, increased BAT thermogenesis and browning of white adipose tissue, and decreased food intake, effects that were absent in MC4R knock-out mice and blocked by the MC4R antagonist, AgRP. Conclusion These data show a novel central anti-obesity mechanism of action of DNP and highlight the potential for selective melanocortin mitochondrial uncoupling to target metabolic disorders. Mitochondrial uncoupling of the melanocortin system with DNP induced weight-loss. DNP inhibited NPY neurones via activation of ATP-sensitive potassium channels. DNP activated POMC neurones via block of inwardly rectifying potassium channels. Central DNP reduced food intake and increased WAT browning and BAT thermogenesis.
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Affiliation(s)
- Natalie Jane Michael
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Australia(5).
| | - Stephanie Elise Simonds
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Australia(5).
| | | | - Michael Alexander Cowley
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Australia(5).
| | - David Spanswick
- Neuroscience Program, Biomedicine Discovery Institute, Monash University, Australia(5); Neurosolutions, Coventry, P.O. 3517, UK; Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
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114
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Ramos-Lobo AM, Donato J. The role of leptin in health and disease. Temperature (Austin) 2017; 4:258-291. [PMID: 28944270 DOI: 10.1080/23328940.2017.1327003] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/27/2017] [Accepted: 05/02/2017] [Indexed: 02/07/2023] Open
Abstract
Leptin is a master regulator of energy balance and body adiposity. Additionally, leptin exerts important control on glucose homeostasis, thermogenesis, autonomic nervous system and neuroendocrine axes. In metabolic diseases, such as obesity and diabetes mellitus, leptin signaling may be compromised, indicating the important role of this hormone in the etiology and pathophysiological manifestations of these conditions. In the present manuscript, we reviewed important concepts of leptin signaling, as well as about the effects of leptin on several biologic functions. We also discussed the possible therapeutic use of leptin administration and how our current obesogenic environment contributes to the development of leptin resistance. Our objective was to provide a comprehensive and state-of-the-art review about the importance of leptin to maintain the homeostasis and during pathological conditions.
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Affiliation(s)
- Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
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115
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Burke LK, Darwish T, Cavanaugh AR, Virtue S, Roth E, Morro J, Liu SM, Xia J, Dalley JW, Burling K, Chua S, Vidal-Puig T, Schwartz GJ, Blouet C. mTORC1 in AGRP neurons integrates exteroceptive and interoceptive food-related cues in the modulation of adaptive energy expenditure in mice. eLife 2017; 6. [PMID: 28532548 PMCID: PMC5441868 DOI: 10.7554/elife.22848] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 04/18/2017] [Indexed: 01/19/2023] Open
Abstract
Energy dissipation through interscapular brown adipose tissue (iBAT) thermogenesis is an important contributor to adaptive energy expenditure. However, it remains unresolved how acute and chronic changes in energy availability are detected by the brain to adjust iBAT activity and maintain energy homeostasis. Here, we provide evidence that AGRP inhibitory tone to iBAT represents an energy-sparing circuit that integrates environmental food cues and internal signals of energy availability. We establish a role for the nutrient-sensing mTORC1 signaling pathway within AGRP neurons in the detection of environmental food cues and internal signals of energy availability, and in the bi-directional control of iBAT thermogenesis during nutrient deficiency and excess. Collectively, our findings provide insights into how mTORC1 signaling within AGRP neurons surveys energy availability to engage iBAT thermogenesis, and identify AGRP neurons as a neuronal substrate for the coordination of energy intake and adaptive expenditure under varying physiological and environmental contexts. DOI:http://dx.doi.org/10.7554/eLife.22848.001 Losing weight through dieting can be difficult. Weight loss strategies often prove ineffective because the body works like a thermostat and couples what we eat to the number of calories we burn. When we eat less, our bodies compensate and burn fewer calories, which makes losing weight harder. The brain is the master regulator of this caloric thermostat, but it is not clear how it adjusts our energy expenditure to account for how much we have eaten. A structure deep within the brain called the hypothalamus, which helps regulate appetite, is thought to be involved in the caloric thermostat. Activating a group of neurons within the hypothalamus called the agouti-related neuropeptide (AGRP) neurons causes animals to consume large quantities of food. By contrast, inhibiting AGRP neurons causes animals to stop eating almost entirely. Burke et al. studied AGRP neurons in mice. The experiments show that artificially activating the neurons in mice that don’t have access to food increases the animals’ activity levels but reduces the rate at which they burn calories, which helps the mice to maintain their existing weight. Allowing the mice to eat, or even just to see and smell food, switches off this effect and returns energy expenditure to normal. Finally, exposing mice to a high-fat diet for several days inhibits their AGRP neurons, and causes the animals to burn calories at a faster rate. By using up excess calories, this change also helps the animals maintain their existing body weight. The findings of Burke et al. show that AGRP neurons are a key component of the caloric thermostat. By adjusting the rate at which the body burns calories, AGRP neurons can compensate for any changes in food intake and so limit changes in body weight. This work opens up the possibility of developing therapies that disconnect energy expenditure from energy intake to help maintain long-term weight loss. DOI:http://dx.doi.org/10.7554/eLife.22848.002
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Affiliation(s)
- Luke K Burke
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Tamana Darwish
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Althea R Cavanaugh
- Departments of Medicine and Neuroscience, The Albert Einstein College of Medicine, New York, United States
| | - Sam Virtue
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Emma Roth
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Joanna Morro
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Shun-Mei Liu
- Departments of Medicine and Neuroscience, The Albert Einstein College of Medicine, New York, United States
| | - Jing Xia
- Department of Psychology, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
| | - Jeffrey W Dalley
- Department of Psychology, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
| | - Keith Burling
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Streamson Chua
- Departments of Medicine and Neuroscience, The Albert Einstein College of Medicine, New York, United States
| | - Toni Vidal-Puig
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Gary J Schwartz
- Departments of Medicine and Neuroscience, The Albert Einstein College of Medicine, New York, United States
| | - Clémence Blouet
- MRC Metabolic Diseases Unit, Metabolic Research Laboratories, University of Cambridge, Cambridge, United Kingdom.,WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
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116
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Craft CS, Scheller EL. Evolution of the Marrow Adipose Tissue Microenvironment. Calcif Tissue Int 2017; 100:461-475. [PMID: 27364342 PMCID: PMC5618436 DOI: 10.1007/s00223-016-0168-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/21/2016] [Indexed: 12/29/2022]
Abstract
Adipocytes of the marrow adipose tissue (MAT) are distributed throughout the skeleton, are embedded in extracellular matrix, and are surrounded by cells of the hematopoietic and osteogenic lineages. MAT is a persistent component of the skeletal microenvironment and has the potential to impact local processes including bone accrual and hematopoietic function. In this review, we discuss the initial evolution of MAT in vertebrate lineages while emphasizing comparisons to the development of peripheral adipose, hematopoietic, and skeletal tissues. We then apply these evolutionary clues to define putative functions of MAT. Lastly, we explore the regulation of MAT by two major components of its microenvironment, the extracellular matrix and the nerves embedded within. The extracellular matrix and nerves contribute to both rapid and continuous modification of the MAT niche and may help to explain evolutionary conserved mechanisms underlying the coordinated regulation of blood, bone, and MAT within the skeleton.
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Affiliation(s)
- Clarissa S Craft
- Department of Cell Biology & Physiology, Washington University, Saint Louis, MO, 63110, USA
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University, Saint Louis, MO, 63110, USA
| | - Erica L Scheller
- Department of Cell Biology & Physiology, Washington University, Saint Louis, MO, 63110, USA.
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University, Saint Louis, MO, 63110, USA.
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117
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Contreras C, Nogueiras R, Diéguez C, Rahmouni K, López M. Traveling from the hypothalamus to the adipose tissue: The thermogenic pathway. Redox Biol 2017; 12:854-863. [PMID: 28448947 PMCID: PMC5406580 DOI: 10.1016/j.redox.2017.04.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 01/13/2023] Open
Abstract
Brown adipose tissue (BAT) is a specialized tissue critical for non-shivering thermogenesis producing heat through mitochondrial uncoupling; whereas white adipose tissue (WAT) is responsible of energy storage in the form of triglycerides. Another type of fat has been described, the beige adipose tissue; this tissue emerges in existing WAT depots but with thermogenic ability, a phenomenon known as browning. Several peripheral signals relaying information about energy status act in the brain, particularly the hypothalamus, to regulate thermogenesis in BAT and browning of WAT. Different hypothalamic areas have the capacity to regulate the thermogenic process in brown and beige adipocytes through the sympathetic nervous system (SNS). This review discusses important concepts and discoveries about the central control of thermogenesis as a trip that starts in the hypothalamus, and taking the sympathetic roads to reach brown and beige fat to modulate thermogenic functions.
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Affiliation(s)
- Cristina Contreras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
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118
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Pandit R, Beerens S, Adan RAH. Role of leptin in energy expenditure: the hypothalamic perspective. Am J Physiol Regul Integr Comp Physiol 2017; 312:R938-R947. [PMID: 28356295 DOI: 10.1152/ajpregu.00045.2016] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 01/08/2023]
Abstract
The adipocyte-derived hormone leptin is a peripheral signal that informs the brain about the metabolic status of an organism. Although traditionally viewed as an appetite-suppressing hormone, studies in the past decade have highlighted the role of leptin in energy expenditure. Leptin has been shown to increase energy expenditure in particular through its effects on the cardiovascular system and brown adipose tissue (BAT) thermogenesis via the hypothalamus. The current review summarizes the role of leptin signaling in various hypothalamic nuclei and its effects on the sympathetic nervous system to influence blood pressure, heart rate, and BAT thermogenesis. Specifically, the role of leptin signaling on three different hypothalamic nuclei, the dorsomedial hypothalamus, the ventromedial hypothalamus, and the arcuate nucleus, is reviewed. It is known that all of these brain regions influence the sympathetic nervous system activity and thereby regulate BAT thermogenesis and the cardiovascular system. Thus the current work focuses on how leptin signaling in specific neuronal populations within these hypothalamic nuclei influences certain aspects of energy expenditure.
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Affiliation(s)
- R Pandit
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - S Beerens
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R A H Adan
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
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119
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Martins FF, Bargut TCL, Aguila MB, Mandarim-de-Lacerda CA. Thermogenesis, fatty acid synthesis with oxidation, and inflammation in the brown adipose tissue of ob/ob (−/−) mice. Ann Anat 2017; 210:44-51. [DOI: 10.1016/j.aanat.2016.11.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 11/10/2016] [Accepted: 11/22/2016] [Indexed: 01/17/2023]
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120
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121
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Hill JW, Faulkner LD. The Role of the Melanocortin System in Metabolic Disease: New Developments and Advances. Neuroendocrinology 2017; 104:330-346. [PMID: 27728914 PMCID: PMC5724371 DOI: 10.1159/000450649] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/01/2016] [Indexed: 12/17/2022]
Abstract
Obesity is increasing in prevalence across all sectors of society, and with it a constellation of associated ailments including hypertension, type 2 diabetes, and eating disorders. The melanocortin system is a critical neural system underlying the control of body weight and other functions. Deficits in the melanocortin system may promote or exacerbate the comorbidities of obesity. This system has therefore generated great interest as a potential target for treatment of obesity. However, drugs targeting melanocortin receptors are plagued by problematic side effects, including undesirable increases in sympathetic nervous system activity, heart rate, and blood pressure. Circumnavigating this roadblock will require a clearer picture of the precise neural circuits that mediate the functions of melanocortins. Recent, novel experimental approaches have significantly advanced our understanding of these pathways. We here review the latest advances in our understanding of the role of melanocortins in food intake, reward pathways, blood pressure, glucose control, and energy expenditure. The evidence suggests that downstream melanocortin-responsive circuits responsible for different physiological actions do diverge. Ultimately, a more complete understanding of melanocortin pathways and their myriad roles should allow treatments tailored to the mix of metabolic disorders in the individual patient.
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Affiliation(s)
- Jennifer W Hill
- Department of Physiology and Pharmacology, College of Medicine, The University of Toledo, Toledo, OH, USA
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122
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Conceição EPS, Moura EG, Oliveira E, Guarda DS, Figueiredo MS, Quitete FT, Calvino C, Miranda RA, Mathias PCF, Manhães AC, Lisboa PC. Dietary calcium supplementation in adult rats reverts brown adipose tissue dysfunction programmed by postnatal early overfeeding. J Nutr Biochem 2017; 39:117-125. [DOI: 10.1016/j.jnutbio.2016.09.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 07/05/2016] [Accepted: 09/02/2016] [Indexed: 11/28/2022]
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123
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Barateiro A, Mahú I, Domingos AI. Leptin Resistance and the Neuro-Adipose Connection. Front Endocrinol (Lausanne) 2017; 8:45. [PMID: 28321206 PMCID: PMC5337508 DOI: 10.3389/fendo.2017.00045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/20/2017] [Indexed: 01/30/2023] Open
Affiliation(s)
- Andreia Barateiro
- Obesity Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, Portugal
| | - Ines Mahú
- Obesity Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Ana I. Domingos
- Obesity Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
- *Correspondence: Ana I. Domingos,
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124
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Burnett LC, Skowronski AA, Rausch R, LeDuc CA, Leibel RL. Determination of the half-life of circulating leptin in the mouse. Int J Obes (Lond) 2016; 41:355-359. [PMID: 28025576 PMCID: PMC5340585 DOI: 10.1038/ijo.2016.238] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/16/2016] [Accepted: 12/11/2016] [Indexed: 01/01/2023]
Abstract
Background The adipokine hormone, leptin, is a major component of body weight homeostasis. Numerous studies have been performed administering recombinant mouse leptin as an experimental reagent; however, the half life of circulating leptin following exogenous administration of recombinant mouse leptin has not been carefully evaluated. Methods Exogenous leptin was administered (3 mg leptin/kg body weight) to ten week old fasted non-obese male mice and plasma was serially collected at seven time points; plasma leptin concentration was measured by ELISA at each time point to estimate the circulating half life of mouse leptin. Results Under the physiological circumstances tested, the half life of mouse leptin was 40.2 (+/− 2.2) minutes. Circulating leptin concentrations up to one hour following exogenous leptin administration were 170-fold higher than endogenous levels at fasting. Conclusions The half life of mouse leptin was determined to be 40.2 minutes. These results should be useful in planning and interpreting experiments employing exogenous leptin. The unphysiological elevations in circulating leptin resulting from widely used dosing regimens for exogenous leptin are likely to confound inferences regarding some aspects of the hormone’s clinical biology.
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Affiliation(s)
- L C Burnett
- Columbia University Institute of Human Nutrition, New York, NY, USA.,Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA
| | - A A Skowronski
- Columbia University Institute of Human Nutrition, New York, NY, USA.,Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA
| | - R Rausch
- Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA
| | - C A LeDuc
- Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA.,New York Obesity Research Center, New York, NY, USA
| | - R L Leibel
- Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA.,New York Obesity Research Center, New York, NY, USA
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125
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Chen M, Shrestha YB, Podyma B, Cui Z, Naglieri B, Sun H, Ho T, Wilson EA, Li YQ, Gavrilova O, Weinstein LS. Gsα deficiency in the dorsomedial hypothalamus underlies obesity associated with Gsα mutations. J Clin Invest 2016; 127:500-510. [PMID: 27991864 DOI: 10.1172/jci88622] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 11/10/2016] [Indexed: 11/17/2022] Open
Abstract
Gsα, encoded by Gnas, mediates hormone and neurotransmitter receptor-stimulated cAMP generation. Heterozygous Gsα-inactivating mutations lead to obesity in Albright hereditary osteodystrophy (AHO) patients, but only when the mutations occur on the maternal allele. This parent-of-origin effect is due to Gsα imprinting in the CNS, although the relevant CNS regions are unknown. We have now shown that mice with a Gnas gene deletion disrupting Gsα expression on the maternal allele, but not the paternal allele, in the dorsomedial nucleus of the hypothalamus (DMH) developed obesity and reduced energy expenditure without hyperphagia. Although maternal Gnas deletion impaired activation of brown adipose tissue (BAT) in mice, their responses to cold environment remained intact. Similar findings were observed in mice with DMH-specific deficiency of melanocortin MC4R receptors, which are known to activate Gsα. Our results show that Gsα imprinting in the DMH underlies the parent-of-origin metabolic phenotype that results from Gsα mutations and that DMH MC4R/Gsα signaling is important for regulation of energy expenditure and BAT activation, but not the metabolic response to cold.
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126
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Contribution of adaptive thermogenesis to the hypothalamic regulation of energy balance. Biochem J 2016; 473:4063-4082. [DOI: 10.1042/bcj20160012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 08/13/2016] [Accepted: 08/30/2016] [Indexed: 12/12/2022]
Abstract
Obesity and its related disorders are among the most pervasive diseases in contemporary societies, and there is an urgent need for new therapies and preventive approaches. Given (i) our poor social capacity to correct unhealthy habits, and (ii) our evolutionarily genetic predisposition to store excess energy as fat, the current environment of caloric surplus makes the treatment of obesity extremely difficult. During the last few decades, an increasing number of methodological approaches have increased our knowledge of the neuroanatomical basis of the control of energy balance. Compelling evidence underlines the role of the hypothalamus as a homeostatic integrator of metabolic information and its ability to adjust energy balance. A greater understanding of the neural basis of the hypothalamic regulation of energy balance might indeed pave the way for new therapeutic targets. In this regard, it has been shown that several important peripheral signals, such as leptin, thyroid hormones, oestrogens and bone morphogenetic protein 8B, converge on common energy sensors, such as AMP-activated protein kinase to modulate sympathetic tone on brown adipose tissue. This knowledge may open new ways to counteract the chronic imbalance underlying obesity. Here, we review the current state of the art on the role of hypothalamus in the regulation of energy balance with particular focus on thermogenesis.
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127
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Dynamic GABAergic afferent modulation of AgRP neurons. Nat Neurosci 2016; 19:1628-1635. [PMID: 27643429 PMCID: PMC5382799 DOI: 10.1038/nn.4392] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 08/22/2016] [Indexed: 02/07/2023]
Abstract
Agouti-related peptide (AgRP) neurons of the arcuate nucleus of the hypothalamus (ARC) promote homeostatic feeding at times of caloric insufficiency, yet they are rapidly suppressed by food-related sensory cues prior to ingestion. Here we identify a highly selective inhibitory afferent to AgRP neurons that serves as a neural determinant of this rapid modulation. Specifically, GABAergic projections arising from the ventral compartment of the dorsomedial nucleus of the hypothalamus (vDMH) contribute to the pre-consummatory modulation of ARCAgRP neurons. In a manner reciprocal to ARCAgRP neurons, ARC-projecting leptin receptor (LepR)-expressing GABAergic DMH neurons exhibit rapid activation upon availability of food that additionally reflects the relative value of the food. Thus, DMHLepR neurons form part of the sensory network that relays real-time information about the nature and availability of food to dynamically modulate ARCAgRP neuron activity and feeding behavior.
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128
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Preserving of Postnatal Leptin Signaling in Obesity-Resistant Lou/C Rats following a Perinatal High-Fat Diet. PLoS One 2016; 11:e0162517. [PMID: 27618559 PMCID: PMC5019390 DOI: 10.1371/journal.pone.0162517] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/24/2016] [Indexed: 11/19/2022] Open
Abstract
Physiological processes at adulthood, such as energy metabolism and insulin sensitivity may originate before or weeks after birth. These underlie the concept of fetal and/or neonatal programming of adult diseases, which is particularly relevant in the case of obesity and type 2 diabetes. The aim of this study was to determine the impact of a perinatal high fat diet on energy metabolism and on leptin as well as insulin sensitivity, early in life and at adulthood in two strains of rats presenting different susceptibilities to diet-induced obesity. The impact of a perinatal high fat diet on glucose tolerance and diet-induced obesity was also assessed. The development of glucose intolerance and of increased fat mass was confirmed in the obesity-prone Wistar rat, even after 28 days of age. By contrast, in obesity-resistant Lou/C rats, an improved early leptin signaling may be responsible for the lack of deleterious effect of the perinatal high fat diet on glucose tolerance and increased adiposity in response to high fat diet at adulthood. Altogether, this study shows that, even if during the perinatal period adaptation to the environment appears to be genetically determined, adaptive mechanisms to nutritional challenges occurring at adulthood can still be observed in rodents.
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129
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Brúsik M, Štrbová Z, Petrášová D, Pobeha P, Kuklišová Z, Tkáčová R, Joppa P. Increased resting energy expenditure and insulin resistance in male patients with moderate-to severe obstructive sleep apnoea. Physiol Res 2016; 65:969-977. [PMID: 27539109 DOI: 10.33549/physiolres.933277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Obstructive sleep apnoea (OSA) has been associated with disturbances in energy metabolism and insulin resistance, nevertheless, the links between OSA severity, resting energy expenditure (REE) and insulin resistance (homeostasis model assessment, HOMA-IR) remained unexplored. Therefore, we investigated the effects of OSA severity on REE, and relationships between REE and HOMA-IR in patients with OSA. Forty men [mean (SD) age 49.4 (11.4) years] underwent overnight polysomnography; REE was assessed using indirect calorimetry. REE adjusted for fat-free mass (FFM) was higher in patients with moderate-to severe OSA [n=24; body mass index (BMI) 31.1 (2.7) kg.m(-2); apnoea-hypopnoea index (AHI)>/=15 episodes.h(-1)] compared to participants with no clinically significant OSA (n=16; BMI 30.3 (2.2) kg.m(-2); AHI<15 episodes.h(-1)) [median (interquartile range) 30.4 (26.1-31.3) versus 25.8 (24.6-27.3) kcal.kg(-1).24 h(-1), p=0.005)]. AHI and oxygen desaturation index (ODI) were directly related to REE/FFM (p=0.001; p<0.001, respectively) and to HOMA-IR (p<0.001 for both). In stepwise multiple linear models, REE/FFM was independently predicted by ODI (p<0.001) and age (p=0.028) (R(2)=0.346); HOMA-IR was independently predicted by ODI only (p<0.001, R(2)=0.457). In conclusion, male patients with moderate-to severe OSA have increased REE paralleled by impaired insulin sensitivity. Severity of nocturnal intermittent hypoxia reflected by ODI is an independent predictor of REE/FFM and HOMA-IR.
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Affiliation(s)
- M Brúsik
- Department of Respiratory Medicine and Tuberculosis, Faculty of Medicine, P. J. Šafárik University in Košice and L. Pasteur University Hospital, Košice, Slovak Republic.
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130
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Bargut TCL, Aguila MB, Mandarim-de-Lacerda CA. Brown adipose tissue: Updates in cellular and molecular biology. Tissue Cell 2016; 48:452-60. [PMID: 27561621 DOI: 10.1016/j.tice.2016.08.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/04/2016] [Accepted: 08/06/2016] [Indexed: 01/12/2023]
Abstract
Brown adipose tissue (BAT) is mainly composed of adipocytes, it is highly vascularized and innervated, and can be activated in adult humans. Brown adipocytes are responsible for performing non-shivering thermogenesis, which is exclusively mediated by uncoupling protein (UCP) -1 (a protein found in the inner mitochondrial membrane), the hallmark of BAT, responsible for the uncoupling of the proton leakage from the ATP production, therefore, generating heat (i.e. thermogenesis). Besides UCP1, other compounds are essential not only to thermogenesis, but also to the proliferation and differentiation of BAT, including peroxisome proliferator-activated receptor (PPAR) family, PPARgamma coactivator 1 (PGC1)-alpha, and PRD1-BF-1-RIZ1 homologous domain protein containing protein (PRDM) -16. The sympathetic nervous system centrally regulates thermogenesis through norepinephrine, which acts on the adrenergic receptors of BAT. This bound leads to the initialization of the many pathways that may activate thermogenesis in acute and/or chronic ways. In summary, this mini-review aims to demonstrate the latest advances in the knowledge of BAT.
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Affiliation(s)
- Thereza Cristina Lonzetti Bargut
- Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Institute of Biology, State University of Rio de Janeiro, Brazil
| | - Marcia Barbosa Aguila
- Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Institute of Biology, State University of Rio de Janeiro, Brazil
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131
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Enriori PJ, Chen W, Garcia-Rudaz MC, Grayson BE, Evans AE, Comstock SM, Gebhardt U, Müller HL, Reinehr T, Henry BA, Brown RD, Bruce CR, Simonds SE, Litwak SA, McGee SL, Luquet S, Martinez S, Jastroch M, Tschöp MH, Watt MJ, Clarke IJ, Roth CL, Grove KL, Cowley MA. α-Melanocyte stimulating hormone promotes muscle glucose uptake via melanocortin 5 receptors. Mol Metab 2016; 5:807-822. [PMID: 27688995 PMCID: PMC5034615 DOI: 10.1016/j.molmet.2016.07.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 01/21/2023] Open
Abstract
Objective Central melanocortin pathways are well-established regulators of energy balance. However, scant data exist about the role of systemic melanocortin peptides. We set out to determine if peripheral α-melanocyte stimulating hormone (α-MSH) plays a role in glucose homeostasis and tested the hypothesis that the pituitary is able to sense a physiological increase in circulating glucose and responds by secreting α-MSH. Methods We established glucose-stimulated α-MSH secretion using humans, non-human primates, and mouse models. Continuous α-MSH infusions were performed during glucose tolerance tests and hyperinsulinemic-euglycemic clamps to evaluate the systemic effect of α-MSH in glucose regulation. Complementary ex vivo and in vitro techniques were employed to delineate the direct action of α-MSH via the melanocortin 5 receptor (MC5R)–PKA axis in skeletal muscles. Combined treatment of non-selective/selective phosphodiesterase inhibitor and α-MSH was adopted to restore glucose tolerance in obese mice. Results Here we demonstrate that pituitary secretion of α-MSH is increased by glucose. Peripheral α-MSH increases temperature in skeletal muscles, acts directly on soleus and gastrocnemius muscles to significantly increase glucose uptake, and enhances whole-body glucose clearance via the activation of muscle MC5R and protein kinase A. These actions are absent in obese mice, accompanied by a blunting of α-MSH-induced cAMP levels in skeletal muscles of obese mice. Both selective and non-selective phosphodiesterase inhibition restores α-MSH induced skeletal muscle glucose uptake and improves glucose disposal in obese mice. Conclusion These data describe a novel endocrine circuit that modulates glucose homeostasis by pituitary α-MSH, which increases muscle glucose uptake and thermogenesis through the activation of a MC5R-PKA-pathway, which is disrupted in obesity. Glucose stimulates α-MSH release from the pituitary. Systemic α-MSH drives glucose disposal and thermogenesis in skeletal muscles. α-MSH acts on MC5R expressed on skeletal muscles and activate cAMP-PKA pathway. The combined treatment of nonselective or selective PDE 4 inhibitor and α-MSH ameliorates glucose intolerance in obese mice.
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Affiliation(s)
- Pablo J Enriori
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Weiyi Chen
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Maria C Garcia-Rudaz
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | | | - Anne E Evans
- Division Neuroscience, Oregon Health and Science University, Oregon, USA
| | - Sarah M Comstock
- Division Neuroscience, Oregon Health and Science University, Oregon, USA
| | - Ursel Gebhardt
- Department of Pediatrics, Vestische Children Hospital Datteln, University of Witten/Herdecke, Germany
| | - Hermann L Müller
- Department of Pediatrics, Vestische Children Hospital Datteln, University of Witten/Herdecke, Germany
| | - Thomas Reinehr
- Department of Pediatrics, Klinikum Oldenburg GmbH, Germany
| | - Belinda A Henry
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Russell D Brown
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Clinton R Bruce
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Stephanie E Simonds
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Sara A Litwak
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Sean L McGee
- Metabolic Research Unit, School of Medicine, Deakin University, Vic, Australia
| | - Serge Luquet
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, F-75205 Paris, France
| | - Sarah Martinez
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, F-75205 Paris, France
| | - Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg & Division of Metabolic Diseases, Technische Universität, München, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg & Division of Metabolic Diseases, Technische Universität, München, Germany
| | - Matthew J Watt
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Iain J Clarke
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia
| | - Christian L Roth
- Division of Endocrinology, Seattle Children's Hospital Research Institute, WA, USA
| | - Kevin L Grove
- Division Neuroscience, Oregon Health and Science University, Oregon, USA
| | - Michael A Cowley
- Biomedical Discovery Institute/Department of Physiology, Monash University, Vic, Australia.
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Lim K, Barzel B, Burke SL, Armitage JA, Head GA. Origin of Aberrant Blood Pressure and Sympathetic Regulation in Diet-Induced Obesity. Hypertension 2016; 68:491-500. [DOI: 10.1161/hypertensionaha.116.07461] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/06/2016] [Indexed: 11/16/2022]
Abstract
High fat diet (HFD)–induced hypertension in rabbits is neurogenic and caused by the central action of leptin, which is thought to be dependent on activation of α-melanocortin–stimulating hormone (α-MSH) and neuropeptide Y–positive neurons projecting to the dorsomedial hypothalamus (DMH) and ventromedial hypothalamus (VMH). However, leptin may act directly in these nuclei. Here, we assessed the contribution of leptin, α-MSH, and neuropeptide Y signaling in the DMH and VMH to diet-induced hypertension. Male New Zealand white rabbits were instrumented with a cannula for drug injections into the DMH or VMH and a renal sympathetic nerve activity (RSNA) electrode. After 3 weeks of an HFD (13.3% fat; n=19), rabbits exhibited higher RSNA, mean arterial pressure (MAP), and heart rate compared with control diet–fed animals (4.2% fat; n=15). Intra-VMH injections of a leptin receptor antagonist or SHU9119, a melanocortin 3/4 receptor antagonist, decreased MAP, heart rate, and RSNA compared with vehicle in HFD rabbits (
P
<0.05) but not in control diet–fed animals. By contrast, α-MSH or neuropeptide Y injected into the VMH had no effect on MAP but produced sympathoexcitation in HFD rabbits (
P
<0.05) but not in control diet–fed rabbits. The effects of the leptin antagonist, α-MSH, or neuropeptide Y injections into the DMH on MAP or RSNA of HFD rabbits were not different from those after vehicle injection. α-MSH into the DMH of control diet–fed animals did increase MAP, heart rate, and RSNA. We conclude that the VMH is the likely origin of leptin-mediated sympathoexcitation and α-MSH hypersensitivity that contribute to obesity-related hypertension.
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Affiliation(s)
- Kyungjoon Lim
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (K.L., B.B., S.L.B., J.A.A., G.A.H.); Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia (B.B., J.A.A.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Benjamin Barzel
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (K.L., B.B., S.L.B., J.A.A., G.A.H.); Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia (B.B., J.A.A.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Sandra L. Burke
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (K.L., B.B., S.L.B., J.A.A., G.A.H.); Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia (B.B., J.A.A.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - James A. Armitage
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (K.L., B.B., S.L.B., J.A.A., G.A.H.); Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia (B.B., J.A.A.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Geoffrey A. Head
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (K.L., B.B., S.L.B., J.A.A., G.A.H.); Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia (B.B., J.A.A.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
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Denroche HC, Glavas MM, Tudurí E, Karunakaran S, Quong WL, Philippe M, Britton HM, Clee SM, Kieffer TJ. Disrupted Leptin Signaling in the Lateral Hypothalamus and Ventral Premammillary Nucleus Alters Insulin and Glucagon Secretion and Protects Against Diet-Induced Obesity. Endocrinology 2016; 157:2671-85. [PMID: 27183315 DOI: 10.1210/en.2015-1998] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leptin signaling in the central nervous system, and particularly the arcuate hypothalamic nucleus, is important for regulating energy and glucose homeostasis. However, the roles of extra-arcuate leptin responsive neurons are less defined. In the current study, we generated mice with widespread inactivation of the long leptin receptor isoform in the central nervous system via Synapsin promoter-driven Cre (Lepr(flox/flox) Syn-cre mice). Within the hypothalamus, leptin signaling was disrupted in the lateral hypothalamic area (LHA) and ventral premammillary nucleus (PMV) but remained intact in the arcuate hypothalamic nucleus and ventromedial hypothalamic nucleus, dorsomedial hypothalamic nucleus, and nucleus of the tractus solitarius. To investigate the role of LHA/PMV neuronal leptin signaling, we examined glucose and energy homeostasis in Lepr(flox/flox) Syn-cre mice and Lepr(flox/flox) littermates under basal and diet-induced obese conditions and tested the role of LHA/PMV neurons in leptin-mediated glucose lowering in streptozotocin-induced diabetes. Lepr(flox/flox) Syn-cre mice did not have altered body weight or blood glucose levels but were hyperinsulinemic and had enhanced glucagon secretion in response to experimental hypoglycemia. Surprisingly, when placed on a high-fat diet, Lepr(flox/flox) Syn-cre mice were protected from weight gain, glucose intolerance, and diet-induced hyperinsulinemia. Peripheral leptin administration lowered blood glucose in streptozotocin-induced diabetic Lepr(flox/flox) Syn-cre mice as effectively as in Lepr(flox/flox) littermate controls. Collectively these findings suggest that leptin signaling in LHA/PMV neurons is not critical for regulating glucose levels but has an indispensable role in the regulation of insulin and glucagon levels and, may promote the development of diet-induced hyperinsulinemia and weight gain.
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Affiliation(s)
- Heather C Denroche
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Maria M Glavas
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Eva Tudurí
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Subashini Karunakaran
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Whitney L Quong
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Marion Philippe
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Heidi M Britton
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Susanne M Clee
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Timothy J Kieffer
- Laboratory of Molecular and Cellular Medicine (H.C.D., M.M.G., E.T., W.L.Q., M.P., H.M.B., T.J.K.) and Laboratory of the Genetics of Obesity and Diabetes (S.K., S.M.C.), Department of Cellular and Physiological Sciences, Life Sciences Institute, and Department of Surgery (T.J.K.), University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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Yamada T. [Inter-organ neural network mediate the regulation of systemic energy metabolism]. Nihon Yakurigaku Zasshi 2016; 148:28-33. [PMID: 27430676 DOI: 10.1254/fpj.148.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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135
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Otgon-Uul Z, Suyama S, Onodera H, Yada T. Optogenetic activation of leptin- and glucose-regulated GABAergic neurons in dorsomedial hypothalamus promotes food intake via inhibitory synaptic transmission to paraventricular nucleus of hypothalamus. Mol Metab 2016; 5:709-715. [PMID: 27656408 PMCID: PMC5021668 DOI: 10.1016/j.molmet.2016.06.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 06/15/2016] [Accepted: 06/16/2016] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE The dorsomedial hypothalamus (DMH) has been considered an orexigenic nucleus, since the DMH lesion reduced food intake and body weight and induced resistance to diet-induced obesity. The DMH expresses feeding regulatory neuropeptides and receptors including neuropeptide Y (NPY), cocaine- and amphetamine-regulated transcript (CART), cholecystokinin (CCK), leptin receptor, and melanocortin 3/4 receptors. However, the principal neurons generating the orexigenic function in the DMH remain to be defined. This study aimed to clarify the role of the DMH GABAergic neurons in feeding regulation by using optogenetics and electrophysiological techniques. METHODS We generated the mice expressing ChRFR-C167A, a bistable chimeric channelrhodopsin, selectively in GABAergic neurons of DMH via locally injected adeno-associated virus 2. Food intake after optogenetic activation of DMH GABAergic neurons was measured. Electrophysiological properties of DMH GABAergic neurons were measured using slice patch clamp. RESULTS Optogenetic activation of DMH GABAergic neurons promoted food intake. Leptin hyperpolarized and lowering glucose depolarized half of DMH GABAergic neurons, suggesting their orexigenic property. Optical activation of axonal terminals of DMH GABAergic neurons at the paraventricular nucleus of hypothalamus (PVN), where anorexigenic neurons are localized, increased inhibitory postsynaptic currents on PVN neurons and promoted food intake. CONCLUSION DMH GABAergic neurons are regulated by metabolic signals leptin and glucose and, once activated, promote food intake via inhibitory synaptic transmission to PVN.
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Affiliation(s)
- Zesemdorj Otgon-Uul
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 320-0498, Japan
| | - Shigetomo Suyama
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 320-0498, Japan
| | - Hiroshi Onodera
- Photon Science Center of the University of Tokyo, Department of Electrical Engineering of the University of Tokyo, Tokyo, Japan
| | - Toshihiko Yada
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 320-0498, Japan.
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136
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Abstract
Increasing energy expenditure is an appealing therapeutic target for the prevention and reversal of metabolic conditions such as obesity or type 2 diabetes. However, not enough research has investigated how to exploit pre-existing neural pathways, both in the central nervous system (CNS) and peripheral nervous system (PNS), in order to meet these needs. Here, we review several research areas in this field, including centrally acting pathways known to drive the activation of sympathetic nerves that can increase lipolysis and browning in white adipose tissue (WAT) or increase thermogenesis in brown adipose tissue (BAT), as well as other central and peripheral pathways able to increase energy expenditure of these tissues. In addition, we describe new work investigating the family of transient receptor potential (TRP) channels on metabolically important sensory nerves, as well as the role of the vagus nerve in regulating energy balance.
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Affiliation(s)
- Magdalena Blaszkiewicz
- School of Biology and Ecology and Graduate School of Biomedical Sciences and Engineering, University of Maine, 5735 Hitchner Hall, Rm 301, Orono, ME, 04469, USA
| | - Kristy L Townsend
- School of Biology and Ecology and Graduate School of Biomedical Sciences and Engineering, University of Maine, 5735 Hitchner Hall, Rm 301, Orono, ME, 04469, USA.
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137
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Croizier S, Prevot V, Bouret SG. Leptin Controls Parasympathetic Wiring of the Pancreas during Embryonic Life. Cell Rep 2016; 15:36-44. [PMID: 27052164 DOI: 10.1016/j.celrep.2016.02.088] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/05/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022] Open
Abstract
The autonomic nervous system plays a critical role in glucose metabolism through both its sympathetic and parasympathetic branches, but the mechanisms that underlie the development of the autonomic innervation of the pancreas remain poorly understood. Here, we report that cholinergic innervation of pancreatic islets develops during mid-gestation under the influence of leptin. Leptin-deficient mice display a greater cholinergic innervation of pancreatic islets beginning in embryonic life, and this increase persists into adulthood. Remarkably, a single intracerebroventricular injection of leptin in embryos caused a permanent reduction in parasympathetic innervation of pancreatic β cells and long-term impairments in glucose homeostasis. These developmental effects of leptin involve a direct inhibitory effect on the outgrowth of preganglionic axons from the hindbrain. These studies reveal an unanticipated regulatory role of leptin on the parasympathetic nervous system during embryonic development and may have important implications for our understanding of the early mechanisms that contribute to diabetes.
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Affiliation(s)
- Sophie Croizier
- The Saban Research Institute, Developmental Neuroscience Program, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA 90027, USA
| | - Vincent Prevot
- INSERM, Jean-Pierre Aubert Research Center, U1172, University Lille 2, Lille 59045, France
| | - Sebastien G Bouret
- The Saban Research Institute, Developmental Neuroscience Program, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA 90027, USA; INSERM, Jean-Pierre Aubert Research Center, U1172, University Lille 2, Lille 59045, France.
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Kim HJ, Oh JE, Koh WU, Ro YJ, Yang HS. Comparison of warming methods for core temperature preservation during total knee arthroplasty using a pneumatic tourniquet. Anesth Pain Med (Seoul) 2016. [DOI: 10.17085/apm.2016.11.1.91] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Ha Jung Kim
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jong Eun Oh
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Won Uk Koh
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Young Jin Ro
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Hong Seuk Yang
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Martinez-Lopez N, Garcia-Macia M, Sahu S, Athonvarangkul D, Liebling E, Merlo P, Cecconi F, Schwartz GJ, Singh R. Autophagy in the CNS and Periphery Coordinate Lipophagy and Lipolysis in the Brown Adipose Tissue and Liver. Cell Metab 2016; 23:113-27. [PMID: 26698918 PMCID: PMC4715637 DOI: 10.1016/j.cmet.2015.10.008] [Citation(s) in RCA: 212] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 08/31/2015] [Accepted: 10/19/2015] [Indexed: 01/22/2023]
Abstract
The integrative physiology of inter-organ communication in lipophagy regulation is not well understood. Lipophagy and the cytosolic lipases ATGL and HSL contribute to lipid droplet (LD) mobilization; however, whether autophagy proteins engage with lipases to promote lipid utilization remains unknown. Here, we show that cold induces autophagy in proopiomelanocortin (POMC) neurons and activates lipophagy in brown adipose tissue (BAT) and liver in mice. Targeted activation of autophagy in POMC neurons via intra-hypothalamic rapamycin is sufficient to trigger lipid utilization in room temperature-housed mice. Conversely, inhibiting autophagy in POMC neurons or in peripheral tissues or denervating BAT blocks lipid utilization. Unexpectedly, the autophagosome marker LC3 is mechanistically coupled to ATGL-mediated lipolysis. ATGL exhibits LC3-interacting region (LIR) motifs, and mutating a single LIR motif on ATGL displaces ATGL from LD and disrupts lipolysis. Thus, cold-induced activation of central autophagy activates lipophagy and cytosolic lipases in a complementary manner to mediate lipolysis in peripheral tissues.
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Affiliation(s)
- Nuria Martinez-Lopez
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Marina Garcia-Macia
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Srabani Sahu
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Diana Athonvarangkul
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Emily Liebling
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Paola Merlo
- Department of Biology, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Francesco Cecconi
- Unit of Cell Stress and Survival, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark; Laboratory of Molecular Neuroembryology, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; Department of Biology, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Gary J Schwartz
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rajat Singh
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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140
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Abstract
Although it has been known for more than a century that the brain controls overall energy balance and adiposity by regulating feeding behavior and energy expenditure, the roles for individual brain regions and neuronal subtypes were not fully understood until recently. This area of research is active, and as such our understanding of the central regulation of energy balance is continually being refined as new details emerge. Much of what we now know stems from the discoveries of leptin and the hypothalamic melanocortin system. Hypothalamic circuits play a crucial role in the control of feeding and energy expenditure, and within the hypothalamus, the arcuate nucleus (ARC) functions as a gateway for hormonal signals of energy balance, such as leptin. It is also well established that the ARC is a primary residence for hypothalamic melanocortinergic neurons. The paraventricular hypothalamic nucleus (PVH) receives direct melanocortin input, along with other integrated signals that affect energy balance, and mediates the majority of hypothalamic output to control both feeding and energy expenditure. Herein, we review in detail the structure and function of the ARC-PVH circuit in mediating leptin signaling and in regulating energy balance.
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Affiliation(s)
- Amy K Sutton
- Departments of Internal Medicine and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48105;
- Division of Endocrinology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan 48105;
| | - Martin G Myers
- Departments of Internal Medicine and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48105;
| | - David P Olson
- Division of Endocrinology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan 48105;
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141
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Wilson JL, Enriori PJ. A talk between fat tissue, gut, pancreas and brain to control body weight. Mol Cell Endocrinol 2015; 418 Pt 2:108-19. [PMID: 26316427 DOI: 10.1016/j.mce.2015.08.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 08/19/2015] [Accepted: 08/20/2015] [Indexed: 12/18/2022]
Abstract
The incidence of obesity and its related disorders are increasing at a rate of pandemic proportions. Understanding the mechanisms behind the maintenance of energy balance is fundamental in developing treatments for clinical syndromes including obesity and diabetes. A neural network located in the nucleus of the solitary tract-area postrema complex in the hindbrain and the hypothalamus in the forebrain has long been implicated in the control of energy balance. In the hypothalamus this central neuronal network consists of small populations of nuclei with distinct functions such as the arcuate nucleus (ARH), the paraventricular nuclei of the hypothalamus (PVH), the dorsomedial (DMH), the ventromedial (VMH) and the lateral hypothalamus (LH). These hypothalamic areas form interconnected neuronal circuits that respond to fluctuations in energy status by altering the expression of neuropeptides, leading to changes in energy intake and expenditure. Regulation of these hypothalamic nuclei involves the actions of orexigenic peptides (ie ghrelin), which act to stimulate energy intake and decrease energy expenditure, and anorexigenic peptides (ie. leptin and insulin), which act to reduce energy intake and stimulate energy expenditure. Here we review the role of the ARH, DMH and PVH in the control of energy homeostasis and how recent advances in research technologies (Cre-loxP technology, optogenetics and pharmacogenetics) have shed light on the role of these hypothalamic nuclei in the control of energy balance. Such novel findings include the implication of ARH POMC and AgRP neurons in the browning of white adipose tissue to regulate energy expenditure as well as the likely existence of divergent hypothalamic pathways in the DMH and PVH in the control of food intake and energy expenditure.
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Affiliation(s)
- Jenny L Wilson
- Department of Physiology, Monash Obesity & Diabetes Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Pablo J Enriori
- Department of Physiology, Monash Obesity & Diabetes Institute, Monash University, Clayton, Victoria 3800, Australia.
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142
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Harris RBS. In vivo evidence for unidentified leptin-induced circulating factors that control white fat mass. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1499-511. [PMID: 26468261 DOI: 10.1152/ajpregu.00335.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/13/2015] [Indexed: 12/29/2022]
Abstract
Fat transplants increase body fat mass without changing the energy status of an animal and provide a tool for investigating control of total body fat. Early transplant studies found that small pieces of transplanted fat took on the morphology of the transplant recipient. Experiments described here tested whether this response was dependent upon expression of leptin receptors in either transplanted fat or the recipient mouse. Fat from leptin receptor deficient db/db mice or wild-type mice was placed subcutaneously in db/db mice. After 12 wk, cell size distribution in the transplant was the same as in endogenous fat of the recipient. Thus, wild-type fat cells, which express leptin receptors, were enlarged in a hyperleptinemic environment, indicating that leptin does not directly control adipocyte size. By contrast, db/db or wild-type fat transplanted into wild-type mice decreased in size, suggesting that a functional leptin system in the recipient is required for body fat mass to be controlled. In the final experiment, wild-type fat was transplanted into a db/db mouse parabiosed to either another db/db mouse to an ob/ob mouse or in control pairs in which both parabionts were ob/ob mice. Transplants increased in size in db/db-db/db pairs, decreased in db/db-ob/ob pairs and did not change in ob/ob-ob/ob pairs. We propose that leptin from db/db parabionts activated leptin receptors in their ob/ob partners. This, in turn, stimulated release of unidentified circulating factors, which travelled back to the db/db partner and acted on the transplant to reduce fat cell size.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
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143
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Abstract
The essential role of the brain in maintaining energy homeostasis has motivated the drive to define the neural circuitry that integrates external and internal stimuli to enact appropriate and consequential metabolic and behavioral responses. The hypothalamus has received significant attention in this regard given its ability to influence feeding behavior, yet organisms rely on a much broader diversity and distribution of neuronal networks to regulate both energy intake and expenditure. Because energy balance is a fundamental determinant of survival and success of an organism, it is not surprising that emerging data connect circuits controlling feeding and energy balance with higher brain functions and degenerative processes. In this review, we will highlight both classically defined and emerging aspects of brain control of energy homeostasis.
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Affiliation(s)
- Michael J Waterson
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
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144
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Badoer E, Kosari S, Stebbing MJ. Resistin, an Adipokine with Non-Generalized Actions on Sympathetic Nerve Activity. Front Physiol 2015; 6:321. [PMID: 26617526 PMCID: PMC4639629 DOI: 10.3389/fphys.2015.00321] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 10/23/2015] [Indexed: 12/18/2022] Open
Abstract
The World Health Organization has called obesity a global epidemic. There is a strong association between body weight gain and blood pressure. A major determinant of blood pressure is the level of activity in sympathetic nerves innervating cardiovascular organs. A characteristic of obesity, in both humans and in animal models, is an increase in sympathetic nerve activity to the skeletal muscle vasculature and to the kidneys. Obesity is now recognized as a chronic, low level inflammatory condition, and pro-inflammatory cytokines are elevated including those produced by adipose tissue. The most well-known adipokine released from fat tissue is leptin. The adipokine, resistin, is also released from adipose tissue. Resistin can act in the central nervous system to influence the sympathetic nerve activity. Here, we review the effects of resistin on sympathetic nerve activity and compare them with leptin. We build an argument that resistin and leptin may have complex interactions. Firstly, they may augment each other as both are excitatory on sympathetic nerves innervating cardiovascular organs; In contrast, they could antagonize each other's actions on brown adipose tissue, a key metabolic organ. These interactions may be important in conditions in which leptin and resistin are elevated, such as in obesity.
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Affiliation(s)
- Emilio Badoer
- School of Medical Sciences and Health Innovations Research Institute, RMIT University Melbourne, VIC, Australia
| | - Samin Kosari
- School of Medical Sciences and Health Innovations Research Institute, RMIT University Melbourne, VIC, Australia
| | - Martin J Stebbing
- School of Medical Sciences and Health Innovations Research Institute, RMIT University Melbourne, VIC, Australia
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145
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Labbé SM, Caron A, Lanfray D, Monge-Rofarello B, Bartness TJ, Richard D. Hypothalamic control of brown adipose tissue thermogenesis. Front Syst Neurosci 2015; 9:150. [PMID: 26578907 PMCID: PMC4630288 DOI: 10.3389/fnsys.2015.00150] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 10/20/2015] [Indexed: 12/21/2022] Open
Abstract
It has long been known, in large part from animal studies, that the control of brown adipose tissue (BAT) thermogenesis is insured by the central nervous system (CNS), which integrates several stimuli in order to control BAT activation through the sympathetic nervous system (SNS). SNS-mediated BAT activity is governed by diverse neurons found in brain structures involved in homeostatic regulations and whose activity is modulated by various factors including oscillations of energy fluxes. The characterization of these neurons has always represented a challenging issue. The available literature suggests that the neuronal circuits controlling BAT thermogenesis are largely part of an autonomic circuitry involving the hypothalamus, brainstem and the SNS efferent neurons. In the present review, we recapitulate the latest progresses in regards to the hypothalamic regulation of BAT metabolism. We briefly addressed the role of the thermoregulatory pathway and its interactions with the energy balance systems in the control of thermogenesis. We also reviewed the involvement of the brain melanocortin and endocannabinoid systems as well as the emerging role of steroidogenic factor 1 (SF1) neurons in BAT thermogenesis. Finally, we examined the link existing between these systems and the homeostatic factors that modulate their activities.
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Affiliation(s)
- Sebastien M Labbé
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Alexandre Caron
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Damien Lanfray
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Boris Monge-Rofarello
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
| | - Timothy J Bartness
- Department of Biology, Center for Obesity Reversal (COR), Georgia State University Atlanta, GA, USA
| | - Denis Richard
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Medicine, Université Laval Québec, QC, Canada
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146
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Seoane-Collazo P, Fernø J, Gonzalez F, Diéguez C, Leis R, Nogueiras R, López M. Hypothalamic-autonomic control of energy homeostasis. Endocrine 2015; 50:276-91. [PMID: 26089260 DOI: 10.1007/s12020-015-0658-y] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 06/06/2015] [Indexed: 10/23/2022]
Abstract
Regulation of energy homeostasis is tightly controlled by the central nervous system (CNS). Several key areas such as the hypothalamus and brainstem receive and integrate signals conveying energy status from the periphery, such as leptin, thyroid hormones, and insulin, ultimately leading to modulation of food intake, energy expenditure (EE), and peripheral metabolism. The autonomic nervous system (ANS) plays a key role in the response to such signals, innervating peripheral metabolic tissues, including brown and white adipose tissue (BAT and WAT), liver, pancreas, and skeletal muscle. The ANS consists of two parts, the sympathetic and parasympathetic nervous systems (SNS and PSNS). The SNS regulates BAT thermogenesis and EE, controlled by central areas such as the preoptic area (POA) and the ventromedial, dorsomedial, and arcuate hypothalamic nuclei (VMH, DMH, and ARC). The SNS also regulates lipid metabolism in WAT, controlled by the lateral hypothalamic area (LHA), VMH, and ARC. Control of hepatic glucose production and pancreatic insulin secretion also involves the LHA, VMH, and ARC as well as the dorsal vagal complex (DVC), via splanchnic sympathetic and the vagal parasympathetic nerves. Muscle glucose uptake is also controlled by the SNS via hypothalamic nuclei such as the VMH. There is recent evidence of novel pathways connecting the CNS and ANS. These include the hypothalamic AMP-activated protein kinase-SNS-BAT axis which has been demonstrated to be a key modulator of thermogenesis. In this review, we summarize current knowledge of the role of the ANS in the modulation of energy balance.
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Affiliation(s)
- Patricia Seoane-Collazo
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain.
| | - Johan Fernø
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- Department of Clinical Science, K. G. Jebsen Center for Diabetes Research, University of Bergen, 5021, Bergen, Norway
| | - Francisco Gonzalez
- Department of Surgery, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- Service of Ophthalmology, Complejo Hospitalario Universitario de Santiago de Compostela, 15706, Santiago de Compostela, Spain
| | - Carlos Diéguez
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Rosaura Leis
- Unit of Investigation in Nutrition, Growth and Human Development of Galicia, Pediatric Department (USC), Complexo Hospitalario Universitario de Santiago (IDIS/SERGAS), Santiago de Compostela, Spain
| | - Rubén Nogueiras
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Miguel López
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain.
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147
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Kooijman S, van den Heuvel JK, Rensen PCN. Neuronal Control of Brown Fat Activity. Trends Endocrinol Metab 2015; 26:657-668. [PMID: 26482876 DOI: 10.1016/j.tem.2015.09.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/18/2015] [Accepted: 09/18/2015] [Indexed: 12/25/2022]
Abstract
Brown adipose tissue (BAT) activation reduces body fat and metabolic disorders by the enhanced combustion of lipids and glucose into heat. The thermogenic activity of brown adipocytes is primarily driven by the sympathetic nervous system (SNS) and controlled by the brain. In this review, we present recent advances in understanding how cues, such as temperature, light, and proteins, modulate the activity of brown fat by acting on the various hypothalamic nuclei. Given that activated BAT has a high capacity to take up and burn fatty acids (FAs) and glucose, pharmacological stimulation of brown fat in humans by either targeting the hypothalamus or mimicking outflow of the sympathetic nervous system might help improve glucose metabolism and insulin sensitivity, and also lower body fat.
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Affiliation(s)
- Sander Kooijman
- Department of Medicine, Division of Endocrinology, and Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands
| | - José K van den Heuvel
- Department of Medicine, Division of Endocrinology, and Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands
| | - Patrick C N Rensen
- Department of Medicine, Division of Endocrinology, and Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands.
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148
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Bruder-Nascimento T, Butler BR, Herren DJ, Brands MW, Bence KK, Belin de Chantemèle EJ. Deletion of protein tyrosine phosphatase 1b in proopiomelanocortin neurons reduces neurogenic control of blood pressure and protects mice from leptin- and sympatho-mediated hypertension. Pharmacol Res 2015; 102:235-44. [PMID: 26523876 DOI: 10.1016/j.phrs.2015.10.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/14/2015] [Accepted: 10/14/2015] [Indexed: 12/15/2022]
Abstract
Protein tyrosine phosphatase 1b (Ptp1b), which represses leptin signaling, is a promising therapeutic target for obesity. Genome wide deletion of Ptp1b, increases leptin sensitivity, protects mice from obesity and diabetes, but alters cardiovascular function by increasing blood pressure (BP). Leptin-control of metabolism is centrally mediated and involves proopiomelanocortin (POMC) neurons. Whether these neurons contribute to leptin-mediated increases in BP remain unclear. We hypothesized that increasing leptin signaling in POMC neurons with Ptp1b deletion will sensitize the cardiovascular system to leptin and enhance neurogenic control of BP. We analyzed the cardiovascular phenotype of Ptp1b+/+ and POMC-Ptp1b-/- mice, at baseline and after 7 days of leptin infusion or sympatho-activation with phenylephrine. POMCPtp1b deletion did not alter baseline cardiovascular hemodynamics (BP, heart rate) but reduced BP response to ganglionic blockade and plasma catecholamine levels that suggests a decreased neurogenic control of BP. In contrast, POMC-Ptp1b deletion increased vascular adrenergic reactivity and aortic α-adrenergic receptors expression. Chronic leptin treatment reduced vascular adrenergic reactivity and blunted diastolic and mean BP increases in POMC-Ptp1b-/- mice only. Similarly POMC-Ptp1b-/- mice exhibited a blunted increased in diastolic and mean BP accompanied by a gradual reduction in adrenergic reactivity in response to chronic vascular sympatho-activation with phenylephrine. Together these data rule out our hypothesis but suggest that deletion of Ptp1b in POMC neurons protects from leptin- and sympatho-mediated increases in BP. Vascular adrenergic desensitization appears as a protective mechanism against hypertension, and POMC-Ptp1b as a key therapeutic target for the treatment of metabolic and cardiovascular dysfunctions associated with obesity.
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Affiliation(s)
- Thiago Bruder-Nascimento
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - Benjamin R Butler
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - David J Herren
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - Michael W Brands
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - Kendra K Bence
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Eric J Belin de Chantemèle
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States.
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149
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Distribution of histaminergic neuronal cluster in the rat and mouse hypothalamus. J Chem Neuroanat 2015; 68:1-13. [DOI: 10.1016/j.jchemneu.2015.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/11/2015] [Accepted: 07/01/2015] [Indexed: 01/03/2023]
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150
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Balland E, Cowley MA. New insights in leptin resistance mechanisms in mice. Front Neuroendocrinol 2015; 39:59-65. [PMID: 26410445 DOI: 10.1016/j.yfrne.2015.09.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 11/18/2022]
Abstract
Leptin resistance is one of the main challenges of obesity. To date, two levels of resistance have been identified, first a decreased rate of leptin uptake into the brain and secondly a diminished central response to leptin. New findings have identified the mechanisms of leptin transport and demonstrated that it can be rescued in obesity, but it did not overcome the problem of central resistance. Alteration in the actions of leptin following diet-induced obesity (DIO) appears to be a multifactorial condition. Several phosphatases are inhibiting leptin signaling pathways in a pathological way. Besides, hypothalamic inflammation alters the neuronal circuits that control metabolism. Recent studies describing both mechanisms (inhibition of leptin signaling and inflammation), have provided key insights to potential new targets for treatment. However, recent data showing that DIO mice may conserve a cellular and physiological response to endogenous leptin, highlights the need to redefine the concept of "leptin resistance".
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Affiliation(s)
- Eglantine Balland
- Department of Physiology, Monash Obesity and Diabetes Institute, Monash University, Clayton, VIC 3800, Australia.
| | - Michael A Cowley
- Department of Physiology, Monash Obesity and Diabetes Institute, Monash University, Clayton, VIC 3800, Australia.
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