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Suda K, Matsuda K. How Microbes Affect Depression: Underlying Mechanisms via the Gut-Brain Axis and the Modulating Role of Probiotics. Int J Mol Sci 2022; 23:ijms23031172. [PMID: 35163104 PMCID: PMC8835211 DOI: 10.3390/ijms23031172] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 02/04/2023] Open
Abstract
Accumulating evidence suggests that the gut microbiome influences the brain functions and psychological state of its host via the gut-brain axis, and gut dysbiosis has been linked to several mental illnesses, including major depressive disorder (MDD). Animal experiments have shown that a depletion of the gut microbiota leads to behavioral changes, and is associated with pathological changes, including abnormal stress response and impaired adult neurogenesis. Short-chain fatty acids such as butyrate are known to contribute to the up-regulation of brain-derived neurotrophic factor (BDNF), and gut dysbiosis causes decreased levels of BDNF, which could affect neuronal development and synaptic plasticity. Increased gut permeability causes an influx of gut microbial components such as lipopolysaccharides, and the resultant systemic inflammation may lead to neuroinflammation in the central nervous system. In light of the fact that gut microbial factors contribute to the initiation and exacerbation of depressive symptoms, this review summarizes the current understanding of the molecular mechanisms involved in MDD onset, and discusses the therapeutic potential of probiotics, including butyrate-producing bacteria, which can mediate the microbiota-gut-brain axis.
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Abstract
There is increasing evidence demonstrating that reward-related motivational food intake is closely connected with the brain's homeostatic system of energy balance and that this interaction might be important in the integrative control of feeding behavior. Dopamine regulates motivational behavior, including feeding behaviors, and the dopamine reward system is recognized as the most prominent system that controls appetite and motivational and emotional drives for food. It appears that the dopamine system exerts a critical role in the control of feeding behavior not only by the reward-related circuit, but also by contributing to the homeostatic circuit of food intake, suggesting that dopamine plays an integrative role across the converging circuitry of control of food intake by linking energy state-associated signals to reward-related behaviors. This review will cover and discuss up-to-date findings on the dopaminergic control of food intake by both the reward-related circuit and the homeostatic hypothalamic system.
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Affiliation(s)
- Ja-Hyun Baik
- Molecular Neurobiology Laboratory, Department of Life Sciences, Korea University, Seoul, Korea
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3
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Li Y, Wu H, Zhang R, Shu G, Wang S, Gao P, Zhu X, Jiang Q, Wang L. Diet containing stearic acid increases food reward-related behaviors in mice compared with oleic acid. Brain Res Bull 2020; 164:45-54. [PMID: 32822805 DOI: 10.1016/j.brainresbull.2020.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 07/30/2020] [Accepted: 08/10/2020] [Indexed: 10/23/2022]
Abstract
Obesity is currently a worldwide phenomenon. The consumption of calorie-rich foods is responsible for most obesity cases, but not all humans exposed to high-calorie diets develop obesity. According to recent studies, exposure to fat-rich diets may be the actual cause of obesity. Dietary long-chain fatty acids affect brain function and are linked to food intake and motivation-related behaviors. Recently, many studies have shown that different types of fatty acids play different roles in animals. In our study, the effects of stearic acid (a saturated fatty acid) and oleic acid (a monounsaturated fatty acid) in diets on hedonic feeding behaviors were investigated, and changes of feeding-related protein levels in the brain were detected to explore the possible mechanism underlying the effects of these fatty acids. As a result, mice fed a diet containing stearic acid, compared to a diet containing oleic acid, exhibited increased food intake, hedonic eating, and an operant response to sucrose and locomotor activity. Furthermore, stearic acid corresponded to a higher level of leptin in serum than oleic acid. In addition, the stearic acid treated group had lower protein levels of p-JAK2 and p-STAT3 in the VTA and a higher dopamine concentration in the NAc than the oleic acid-treated group. Meanwhile, the protein level of TH in the NAc was higher and the protein level of the DA transporter in the VTA was lower in the stearic acid-fed group than in the oleic acid-fed group. In conclusion, these findings indicated that a diet containing stearic acid can increase hedonic feeding behavior and affect mesolimbic dopamine system signals in mice. Moreover, the lowering of serum leptin and leptin signaling in the VTA may contribute to this effect.
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Affiliation(s)
- Yongxiang Li
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Hanyu Wu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Ruixue Zhang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Gang Shu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Songbo Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Ping Gao
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Xiaotong Zhu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Qingyan Jiang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
| | - Lina Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, Guangzhou, Guangdong 510642, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
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4
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Fraga A, Carreira MC, Gonzalez-Izquierdo A, Diéguez C, López M, Gutiérrez E. Temperature but not leptin prevents semi-starvation induced hyperactivity in rats: implications for anorexia nervosa treatment. Sci Rep 2020; 10:5300. [PMID: 32210308 PMCID: PMC7093431 DOI: 10.1038/s41598-020-62147-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/03/2020] [Indexed: 02/06/2023] Open
Abstract
The hypothesis linking hyperactivity with weight loss associated hypoleptinemia in anorexia nervosa gained momentum after a study showing that leptin suppressed semi-starvation induced hyperactivity in rats. Alternatively, ambient temperature is a key modulating factor of activity in semi-starved rats. The aim of the study is to compare the efficacy of leptin with increased ambient temperature in the prevention of hyperactivity in semi-starved rats. 74 Sprague-Dawley male rats were employed in two experiments with the difference residing in the length of baseline. After an extended (28 days), or shorter (14 days) baseline with free access to food and the running wheel, housed at 21 °C, animals were either ad-lib feed or food restricted (60% of food ingested during previous week) and infused with same amount of leptin at 21 °C, 25 °C, or vehicle at 21 °C, 25 °C and 32 °C for a week. Animals housed at 32 °C significantly reduced wheel running and weight loss during food restriction while animals given leptin did not yield no differences in activity or weight loss. Moreover, unlike animals housed at 32 °C, body temperature of leptin infused animals housed at 21 °C was significantly reduced during food restriction. Furthermore, leptin treated rats without a preceding stable pattern of activity displayed a severe dysregulation of circadian rhythm in activity and a collapse of body temperature. Housing temperature plays a more critical role than leptin in the regulation of semi-starvation induced hyperactivity in rats, which may be of relevance for the management of hyperactivity in anorexia nervosa.
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Affiliation(s)
- Angela Fraga
- Department Psicología Clínica y Psicobiología, Facultad de Psicología, Universidad de Santiago, Campus Vida, 15782, Santiago de Compostela, Spain
| | - Marcos C Carreira
- Lab de Endocrinología Molecular, Instituto de Investigaciones Sanitarias de Santiago de Compostela (IDIS), Complej o Hospitalario de Santiago (CHUS), A Coruña, Spain.,CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain
| | - Andrea Gonzalez-Izquierdo
- Lab de Endocrinología Molecular, Instituto de Investigaciones Sanitarias de Santiago de Compostela (IDIS), Complej o Hospitalario de Santiago (CHUS), A Coruña, Spain.,CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain
| | - Carlos Diéguez
- CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.,Department Fisioloxía and Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias de Santiago de Compostela (IDIS), Santiago de Compostela, 15782, Spain
| | - Miguel López
- CIBER Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.,Department Fisioloxía and Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias de Santiago de Compostela (IDIS), Santiago de Compostela, 15782, Spain
| | - Emilio Gutiérrez
- Department Psicología Clínica y Psicobiología, Facultad de Psicología, Universidad de Santiago, Campus Vida, 15782, Santiago de Compostela, Spain. .,Unidad Venres Clínicos, Facultad de Psicología, Campus Vida, Universidad de Santiago, 15782, Santiago de Compostela, Spain.
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5
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Duriez P, Ramoz N, Gorwood P, Viltart O, Tolle V. A Metabolic Perspective on Reward Abnormalities in Anorexia Nervosa. Trends Endocrinol Metab 2019; 30:915-928. [PMID: 31648936 DOI: 10.1016/j.tem.2019.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 08/04/2019] [Accepted: 08/08/2019] [Indexed: 12/17/2022]
Abstract
Anorexia nervosa (AN) is the psychiatric disorder with the highest mortality rate; however, the mechanisms responsible for its pathogenesis remain largely unknown. Large-scale genome-wide association studies (GWAS) have identified genetic loci associated with metabolic features in AN. Metabolic alterations that occur in AN have been mostly considered as consequences of the chronic undernutrition state but until recently have not been linked to the etiology of the disorder. We review the molecular basis of AN based on human genetics, with an emphasis on the molecular components controlling energy homeostasis, highlight the main metabolic and endocrine alterations occurring in AN, and decipher the possible connection between metabolic factors and abnormalities of reward processes that are central in AN.
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Affiliation(s)
- Philibert Duriez
- Institute of Psychiatry and Neurosciences of Paris, Unité Mixte de Recherche en Santé (UMRS) 1266 Institut National de la Santé et de la Recherche Médicale (INSERM), University Paris Descartes, Paris, France; Clinique des Maladies Mentales et de l'Encéphale, Groupement Hospitalier Universitaire (GHU) Paris Psychiatry and Neuroscience, Sainte-Anne Hospital, Paris, France
| | - Nicolas Ramoz
- Institute of Psychiatry and Neurosciences of Paris, Unité Mixte de Recherche en Santé (UMRS) 1266 Institut National de la Santé et de la Recherche Médicale (INSERM), University Paris Descartes, Paris, France
| | - Philip Gorwood
- Institute of Psychiatry and Neurosciences of Paris, Unité Mixte de Recherche en Santé (UMRS) 1266 Institut National de la Santé et de la Recherche Médicale (INSERM), University Paris Descartes, Paris, France; Clinique des Maladies Mentales et de l'Encéphale, Groupement Hospitalier Universitaire (GHU) Paris Psychiatry and Neuroscience, Sainte-Anne Hospital, Paris, France
| | - Odile Viltart
- Institute of Psychiatry and Neurosciences of Paris, Unité Mixte de Recherche en Santé (UMRS) 1266 Institut National de la Santé et de la Recherche Médicale (INSERM), University Paris Descartes, Paris, France; University of Lille, Lille, France
| | - Virginie Tolle
- Institute of Psychiatry and Neurosciences of Paris, Unité Mixte de Recherche en Santé (UMRS) 1266 Institut National de la Santé et de la Recherche Médicale (INSERM), University Paris Descartes, Paris, France.
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6
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do Carmo JM, da Silva AA, Gava FN, Moak SP, Dai X, Hall JE. Impact of leptin deficiency compared with neuronal-specific leptin receptor deletion on cardiometabolic regulation. Am J Physiol Regul Integr Comp Physiol 2019; 317:R552-R562. [PMID: 31411897 DOI: 10.1152/ajpregu.00077.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The main goal of this study was to compare the impact of total body leptin deficiency with neuronal-specific leptin receptor (LR) deletion on metabolic and cardiovascular regulation. Liver fat, diacylglycerol acyltransferase-2 (DGTA2), and CD36 protein content were measured in wild-type (WT), nervous system LR-deficient (LR/Nestin-Cre), and leptin deficient (ob/ob) mice. Blood pressure (BP) and heart rate (HR) were recorded by telemetry, and motor activity (MA) and oxygen consumption (V̇o2) were monitored at 24 wk of age. Female and male LR/Nestin-Cre and ob/ob mice were heavier than WT mice (62 ± 5 and 61 ± 3 vs. 31 ± 1 g) and hyperphagic (6.2 ± 0.5 and 6.1 ± 0.7 vs. 3.5 ± 1.0 g/day), with reduced V̇o2 (27 ± 1 and 33 ± 1 vs 49 ± 3 ml·kg-1·min-1) and decreased MA (3 ± 1 and 7 ± 2 vs 676 ± 105 cm/h). They were also hyperinsulinemic and hyperglycemic compared with WT mice. LR/Nestin-Cre mice had high levels of plasma leptin, while ob/ob mice had undetectable leptin levels. Despite comparable obesity, LR/Nestin-Cre mice had lower liver fat content, DGTA2, and CD36 protein levels than ob/ob mice. Male WT, LR/Nestin-Cre, and ob/ob mice exhibited similar BP (111 ± 3, 110 ± 1 and 109 ± 2 mmHg). Female LR/Nestin-Cre and ob/ob mice, however, had higher BP than WT females despite similar metabolic phenotypes compared with male LR/Nestin-Cre and ob/ob mice. These results indicate that although nervous system LRs play a crucial role in regulating body weight and glucose homeostasis, peripheral LRs regulate liver fat deposition. In addition, our results suggest potential sex differences in the impact of obesity on BP regulation.
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Affiliation(s)
- Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Fabio N Gava
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Sydney P Moak
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xuemei Dai
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
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7
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Borges BC, Han X, Allen SJ, Garcia-Galiano D, Elias CF. Insulin signaling in LepR cells modulates fat and glucose homeostasis independent of leptin. Am J Physiol Endocrinol Metab 2019; 316:E121-E134. [PMID: 30376348 PMCID: PMC6417687 DOI: 10.1152/ajpendo.00287.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypothalamic neurons detect changes in circulating hormones such as leptin and insulin and put forward outputs to sustain energy and glucose homeostasis. Because leptin and insulin receptors colocalize in ~40-60% of neurons in the hypothalamus, we characterized the metabolic phenotype of mice with selective deletion of the insulin receptor (InsR) in LepR cells. LRΔInsR mice presented no difference in body weight and insulin levels but increased fat mass. In the light phase, LRΔInsR mice exhibited increased food intake, locomotor activity, carbon dioxide production, and respiratory exchange rate. These mice showed reduced fat oxidation and reduced expression of cluster of differentiation 36 and AMP-activated protein kinase-α1 in the liver, increased glucose oxidation in the light phase, and overall reduced basal glucose levels. To verify the impact of InsR deletion in LepR cells in obesity, we generated ob/ ob InsRfl, ob/ ob LRcre, and ob/ ob LRΔInsR mice. The ob/ ob LRΔInsR mice had higher body weight, fat mass, and expression of genes related to fat metabolism in the liver. No difference in food intake despite increased neuropeptide Y and agouti-related peptide expression, and no difference in energy expenditure, fat, or glucose oxidation was found in ob/ ob LRΔInsR compared with LRcre or LRΔInsR controls. Remarkably, basal glucose levels were reduced, and the expression of genes associated with glucose metabolism in the liver was higher. Insulin signaling in LepR cells is required for the proper fat and glucose oxidation. These effects are independent of leptin given that the leptin-deficient ob/ ob LRΔInsR mice also presented reduced glycemia and higher adiposity. The mechanisms underlying these responses remain to be unveiled.
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Affiliation(s)
- Beatriz C Borges
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo , Brazil
| | - Xingfa Han
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
- Isotope Research Laboratory, Sichuan Agricultural University, Ya'an, People's Republic of China
| | - Susan J Allen
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
| | - David Garcia-Galiano
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
| | - Carol F Elias
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
- Department of Obstetrics and Gynecology, University of Michigan , Ann Arbor, Michigan
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8
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Evans MC, Kumar NS, Inglis MA, Anderson GM. Leptin and insulin do not exert redundant control of metabolic or emotive function via dopamine neurons. Horm Behav 2018; 106:93-104. [PMID: 30292429 DOI: 10.1016/j.yhbeh.2018.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 11/16/2022]
Abstract
Leptin and insulin's hunger-suppressing and activity-promoting actions on hypothalamic neurons are well characterized, yet the mechanisms by which they modulate the midbrain dopamine system to influence energy balance remain less clear. A subset of midbrain dopamine neurons express receptors for leptin (Lepr) and insulin (Insr). Leptin-dopamine signaling reduces running reward and homecage activity. However, dopamine-specific deletion of Lepr does not affect body weight or food intake in mice. We hypothesized insulin-dopamine signaling might compensate for disrupted leptin-dopamine signaling. To investigate the degree to which insulin and leptin exert overlapping (i.e. redundant) versus discrete control over dopamine neurons, we generated transgenic male and female mice exhibiting dopamine-specific deletion of either Lepr (Lepr KO), Insr (Insr KO) or both Lepr and Insr (Dbl KO) and assessed their feeding behavior, voluntary activity, and energy expenditure compared to control mice. No differences in body weight, daily food intake, energy expenditure or hyperphagic feeding of palatable chow were observed between Lepr, Insr or Dbl KO mice and control mice. However, consistent with previous findings, Lepr KO (but not Insr or Dbl KO) male mice exhibited significantly increased running wheel activity compared to controls. These data demonstrate that insulin and leptin do not exert redundant control of dopamine neuron-mediated modulation of energy balance. Furthermore, our results indicate neither leptin nor insulin plays a critical role in the modulation of dopamine neurons regarding hedonic feeding behavior or anxiety-related behavior.
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Affiliation(s)
- Maggie C Evans
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand.
| | - Nivesh S Kumar
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Megan A Inglis
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Greg M Anderson
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
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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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10
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Simonds SE, Cowley MA. Leptin Effects on DAT Neurons To Control Energy Homeostasis. Endocrinology 2017; 158:4126-4128. [PMID: 29211902 DOI: 10.1210/en.2017-00820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 11/19/2022]
Affiliation(s)
- Stephanie E Simonds
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Australia
| | - Michael A Cowley
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Australia
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