scholarly journals Hypothalamic AMPK as a Mediator of Hormonal Regulation of Energy Balance

2018 ◽  
Vol 19 (11) ◽  
pp. 3552 ◽  
Author(s):  
Baile Wang ◽  
Kenneth Cheng
Keyword(s):  
Energy Balance ◽  
Hormonal Regulation ◽  
Energy Homeostasis ◽  
Adenosine Monophosphate ◽  
Acid Oxidation ◽  
Peripheral Tissues ◽  
Adaptive Thermogenesis ◽  
Increase Food Intake ◽  
Regulatory Effects ◽  
Underlying Mechanisms

As a cellular energy sensor and regulator, adenosine monophosphate (AMP)-activated protein kinase (AMPK) plays a pivotal role in the regulation of energy homeostasis in both the central nervous system (CNS) and peripheral organs. Activation of hypothalamic AMPK maintains energy balance by inducing appetite to increase food intake and diminishing adaptive thermogenesis in adipose tissues to reduce energy expenditure in response to food deprivation. Numerous metabolic hormones, such as leptin, adiponectin, ghrelin and insulin, exert their energy regulatory effects through hypothalamic AMPK via integration with the neural circuits. Although activation of AMPK in peripheral tissues is able to promote fatty acid oxidation and insulin sensitivity, its chronic activation in the hypothalamus causes obesity by inducing hyperphagia in both humans and rodents. In this review, we discuss the role of hypothalamic AMPK in mediating hormonal regulation of feeding and adaptive thermogenesis, and summarize the diverse underlying mechanisms by which central AMPK maintains energy homeostasis.

scholarly journals Broken Energy Homeostasis and Obesity Pathogenesis: The Surrounding Concepts

2018 ◽  
Vol 7 (11) ◽  
pp. 453 ◽  
Author(s):  
Abdelaziz Ghanemi ◽  
Mayumi Yoshioka ◽  
Jonny St-Amand
Keyword(s):  
Energy Balance ◽  
Population Health ◽  
Clinical Evaluation ◽  
Health Problem ◽  
Psychological Factors ◽  
Energy Homeostasis ◽  
Fat Accumulation ◽  
Underlying Mechanisms ◽  
Diagnosis Classification

Obesity represents an abnormal fat accumulation resulting from energy imbalances. It represents a disease with heavy consequences on population health and society economy due to its related morbidities and epidemic proportion. Defining and classifying obesity and its related parameters of evaluation is the first challenge toward understanding this multifactorial health problem. Therefore, within this review we report selected illustrative examples of the underlying mechanisms beyond the obesity pathogenesis which is systemic rather than limited to fat accumulation. We also discuss the gut-brain axis and hormones as the controllers of energy homeostasis and report selected impacts of obesity on the key metabolic tissues. The concepts of “broken energy balance” is detailed as the obesity starting key step. Sleep shortage and psychological factors are also reported with influences on obesity development. Importantly, describing such mechanistic pathways would allow clinicians, biologists and researchers to develop and optimize approaches and methods in terms of diagnosis, classification, clinical evaluation, treatment and prognosis of obesity.

scholarly journals The Pleiotropic Potential of BDNF beyond Neurons: Implication for a Healthy Mind in a Healthy Body

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1256
Author(s):  
Maria Carmela Di Rosa ◽  
Stefania Zimbone ◽  
Miriam Wissam Saab ◽  
Marianna Flora Tomasello
Keyword(s):  
Energy Balance ◽  
Energy Homeostasis ◽  
Molecular Mechanisms ◽  
Cellular Level ◽  
Adaptive Responses ◽  
Peripheral Tissues ◽  
The Central Nervous System ◽  
The Many ◽  
Feeding Control ◽  
Healthy Body

Brain-derived neurotrophic factor (BDNF) represents one of the most widely studied neurotrophins because of the many mechanisms in which it is involved. Among these, a growing body of evidence indicates BDNF as a pleiotropic signaling molecule and unveils non-negligible implications in the regulation of energy balance. BDNF and its receptor are extensively expressed in the hypothalamus, regions where peripheral signals, associated with feeding control and metabolism activation, and are integrated to elaborate anorexigenic and orexigenic effects. Thus, BDNF coordinates adaptive responses to fluctuations in energy intake and expenditure, connecting the central nervous system with peripheral tissues, including muscle, liver, and the adipose tissue in a complex operational network. This review discusses the latest literature dealing with the involvement of BDNF in the maintenance of energy balance. We have focused on the physiological and molecular mechanisms by which BDNF: (I) controls the mitochondrial function and dynamics; (II) influences thermogenesis and tissue differentiation; (III) mediates the effects of exercise on cognitive functions; and (IV) modulates insulin sensitivity and glucose transport at the cellular level. Deepening the understanding of the mechanisms exploited to maintain energy homeostasis will lay the groundwork for the development of novel therapeutical approaches to help people to maintain a healthy mind in a healthy body.

Neural control of the anorexia-cachexia syndrome

2008 ◽  
Vol 295 (5) ◽  
pp. E1000-E1008 ◽  
Author(s):  
Alessandro Laviano ◽  
Akio Inui ◽  
Daniel L. Marks ◽  
Michael M. Meguid ◽  
Claude Pichard ◽  
...  
Keyword(s):  
Neural Control ◽  
Energy Homeostasis ◽  
Hepatic Metabolism ◽  
Metabolic Changes ◽  
Tissue Loss ◽  
Acid Oxidation ◽  
Melanocortin System ◽  
Peripheral Tissues ◽  
Inflammatory State ◽  
Cachexia Syndrome

The anorexia-cachexia syndrome is a debilitating clinical condition characterizing the course of chronic diseases, which heavily impacts on patients' morbidity and quality of life, ultimately accelerating death. The pathogenesis is multifactorial and reflects the complexity and redundancy of the mechanisms controlling energy homeostasis under physiological conditions. Accumulating evidence indicates that, during disease, disturbances of the hypothalamic pathways controlling energy homeostasis occur, leading to profound metabolic changes in peripheral tissues. In particular, the hypothalamic melanocortin system does not respond appropriately to peripheral inputs, and its activity is diverted largely toward the promotion of catabolic stimuli (i.e., reduced energy intake, increased energy expenditure, possibly increased muscle proteolysis, and adipose tissue loss). Hypothalamic proinflammatory cytokines and serotonin, among other factors, are key in triggering hypothalamic resistance. These catabolic effects represent the central response to peripheral challenges (i.e., growing tumor, renal, cardiac failure, disrupted hepatic metabolism) that are likely sensed by the brain through the vagus nerve. Also, disease-induced changes in fatty acid oxidation within hypothalamic neurons may contribute to the dysfunction of the hypothalamic melanocortin system. Ultimately, sympathetic outflow mediates, at least in part, the metabolic changes in peripheral tissues. Other factors are likely involved in the pathogenesis of the anorexia-cachexia syndrome, and their role is currently being elucidated. However, available evidence shows that the constellation of symptoms characterizing this syndrome should be considered, at least in part, as different phenotypes of common neurochemical/metabolic alterations in the presence of a chronic inflammatory state.

scholarly journals Hypothalamic AMPK as a Regulator of Energy Homeostasis

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
My Khanh Q. Huynh ◽  
Ann W. Kinyua ◽  
Dong Joo Yang ◽  
Ki Woo Kim
Keyword(s):  
Energy Balance ◽  
Energy Homeostasis ◽  
Energy State ◽  
Glucose Production ◽  
Energy Output ◽  
Energy Sensor ◽  
Increase Energy Intake ◽  
Ampk Activity ◽  
Underlying Mechanisms ◽  
Amp Activated Protein Kinase

Activated in energy depletion conditions, AMP-activated protein kinase (AMPK) acts as a cellular energy sensor and regulator in both central nervous system and peripheral organs. Hypothalamic AMPK restores energy balance by promoting feeding behavior to increase energy intake, increasing glucose production, and reducing thermogenesis to decrease energy output. Besides energy state, many hormones have been shown to act in concert with AMPK to mediate their anorexigenic and orexigenic central effects as well as thermogenic influences. Here we explore the factors that affect hypothalamic AMPK activity and give the underlying mechanisms for the role of central AMPK in energy homeostasis together with the physiological effects of hypothalamic AMPK on energy balance restoration.

The effects of dietary methionine restriction on the function and metabolic reprogramming in the liver and brain – implications for longevity

2019 ◽  
Vol 30 (6) ◽  
pp. 581-593 ◽  
Author(s):  
Dušan Mladenović ◽  
Tatjana Radosavljević ◽  
Dragan Hrnčić ◽  
Aleksandra Rasic-Markovic ◽  
Olivera Stanojlović
Keyword(s):  
Growth Factor ◽  
Life Span ◽  
De Novo ◽  
Regulatory Element ◽  
Adenosine Monophosphate ◽  
Metabolic Reprogramming ◽  
Fibroblast Growth Factor 21 ◽  
Acid Oxidation ◽  
Peripheral Tissues ◽  
Methionine Restriction

Abstract Methionine is an essential sulphur-containing amino acid involved in protein synthesis, regulation of protein function and methylation reactions. Dietary methionine restriction (0.12–0.17% methionine in food) extends the life span of various animal species and delays the onset of aging-associated diseases and cancers. In the liver, methionine restriction attenuates steatosis and delays the development of non-alcoholic steatohepatitis due to antioxidative action and metabolic reprogramming. The limited intake of methionine stimulates the fatty acid oxidation in the liver and the export of lipoproteins as well as inhibits de novo lipogenesis. These effects are mediated by various signaling pathways and effector molecules, including sirtuins, growth hormone/insulin-like growth factor-1 axis, sterol regulatory element binding proteins, adenosine monophosphate-dependent kinase and general control nonderepressible 2 pathway. Additionally, methionine restriction stimulates the synthesis of fibroblast growth factor-21 in the liver, which increases the insulin sensitivity of peripheral tissues. In the brain, methionine restriction delays the onset of neurodegenerative diseases and increases the resistance to various forms of stress through antioxidative effects and alterations in lipid composition. This review aimed to summarize the morphological, functional and molecular changes in the liver and brain caused by the methionine restriction, with possible implications in the prolongation of maximal life span.

Serotonin and energy balance: molecular mechanisms and implications for type 2 diabetes

2007 ◽  
Vol 9 (5) ◽  
pp. 1-24 ◽  
Author(s):  
Daniel D. Lam ◽  
Lora K. Heisler
Keyword(s):  
Type 2 Diabetes ◽  
Energy Balance ◽  
Glucose Homeostasis ◽  
Metabolic Regulation ◽  
Energy Homeostasis ◽  
Molecular Mechanisms ◽  
Peripheral Tissues ◽  
Midbrain Raphe Nuclei ◽  
Treatment Of Obesity

The neurotransmitter serotonin is an important regulator of energy balance. In the brain, serotonergic fibres from midbrain raphe nuclei project to key feeding centres, where serotonin acts on specific receptors to modulate the activity of various downstream neuropeptide systems and autonomic pathways and thus affects ingestive behaviour and energy expenditure. Serotonin, released by intestinal enterochromaffin cells, also appears to regulate energy homeostasis through peripheral mechanisms. Serotonergic effects on energy balance lead to secondary effects on glucose homeostasis, based on a well-established link between obesity and insulin resistance. However, serotonergic pathways may also directly affect glucose homeostasis through regulation of autonomic efferents and/or action on peripheral tissues. Several serotonergic compounds have been evaluated for clinical use in the treatment of obesity and type 2 diabetes; results of these trials are discussed here. Finally, future directions in the elucidation of serotonergic metabolic regulation are discussed.

scholarly journals Mechanisms for sex differences in energy homeostasis

2019 ◽  
Vol 62 (2) ◽  
pp. R129-R143 ◽  
Author(s):  
Chunmei Wang ◽  
Yong Xu
Keyword(s):  
Sex Differences ◽  
Energy Balance ◽  
Sex Hormones ◽  
Sex Chromosomes ◽  
Energy Homeostasis ◽  
Liver Fat ◽  
Sexually Dimorphic ◽  
Multiple Organs ◽  
Specific Regulation ◽  
Underlying Mechanisms

Sex differences exist in the regulation of energy homeostasis. Better understanding of the underlying mechanisms for sexual dimorphism in energy balance may facilitate development of gender-specific therapies for human diseases, e.g. obesity. Multiple organs, including the brain, liver, fat and muscle, play important roles in the regulations of feeding behavior, energy expenditure and physical activity, which therefore contribute to the maintenance of energy balance. It has been increasingly appreciated that this multi-organ system is under different regulations in male vs female animals. Much of effort has been focused on roles of sex hormones (including androgens, estrogens and progesterone) and sex chromosomes in this sex-specific regulation of energy balance. Emerging evidence also indicates that other factors (not sex hormones/receptors and not encoded by the sex chromosomes) exist to regulate energy homeostasis differentially in males vs females. In this review, we summarize factors and signals that have been shown to regulate energy homeostasis in a sexually dimorphic fashion and propose a framework where these factors and signals may be integrated to mediate sex differences in energy homeostasis.

scholarly journals Herbal SGR Formula Prevents Acute Ethanol-Induced Liver Steatosis via Inhibition of Lipogenesis and Enhancement Fatty Acid Oxidation in Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ping Qiu ◽  
Xiang Li ◽  
De-song Kong ◽  
Huan-zhou Li ◽  
Cong-cong Niu ◽  
...  
Keyword(s):  
Side Effects ◽  
Regulatory Element ◽  
Liver Steatosis ◽  
Adenosine Monophosphate ◽  
Toxicity Tests ◽  
Acid Oxidation ◽  
Protective Effects ◽  
Histopathological Changes ◽  
Acute Ethanol ◽  
Underlying Mechanisms

Our previous study indicated that herbal SGR formula partially attenuates ethanol-induced fatty liver, but the underlying mechanisms remain unclear. In the present study, mice were pretreated with SGR (100 and 200 mg/kg/d bw) for 30 d before being exposed to ethanol (4.8 g/kg bw). The biochemical indices and histopathological changes were examined to evaluate the protective effects and to explore potential mechanisms by investigating the adiponectin, tumor necrosis factor-α(TNF-α), peroxisome proliferators-activated receptor-α(PPAR-α), sterol regulatory element binding protein-1c (SREBP-1c), adenosine monophosphate-activated protein kinase (AMPK), and so forth. Results showed that SGR pretreatment markedly inhibited acute ethanol-induced liver steatosis, significantly reduced serum and hepatic triglyceride (TG) level, and improved classic histopathological changes. SGR suppressed the protein expression of hepatic SREBP-1c and TNF-αand increased adiponectin, PPAR-α, and AMPK phosphorylation in the liver. Meanwhile, acute toxicity tests showed that no death or toxic side effects within 14 days were observed upon oral administration of the extracts at a dose of 16 g/kg body wt. These results demonstrate that SGR could protect against acute alcohol-induced liver steatosis without any toxic side effects. Therefore, our studies provide novel molecular insights into the hepatoprotective effect of SGR formula, which may be exploited as a therapeutic agent for ethanol-induced hepatosteatosis.

Berberine improves lipid dysregulation in obesity by controlling central and peripheral AMPK activity

2009 ◽  
Vol 296 (4) ◽  
pp. E812-E819 ◽  
Author(s):  
Woo Sik Kim ◽  
Yun Sok Lee ◽  
Seung Hun Cha ◽  
Hyun Woo Jeong ◽  
Sung Sik Choe ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Liver ◽  
Fatty Acid Oxidation ◽  
Energy Homeostasis ◽  
Liver Weight ◽  
Whole Body ◽  
Acid Oxidation ◽  
Peripheral Tissues ◽  
Expression Of Genes ◽  
Ampk Activity

AMP-activated protein kinase (AMPK) plays an important role in regulating whole body energy homeostasis. Recently, it has been demonstrated that berberine (BBR) exerts antiobesity and antidiabetic effects in obese and diabetic rodent models through the activation of AMPK in peripheral tissues. Here we show that BBR improves lipid dysregulation and fatty liver in obese mice through central and peripheral actions. In obese db/db and ob/ob mice, BBR treatment reduced liver weight, hepatic and plasma triglyceride, and cholesterol contents. In the liver and muscle of db/db mice, BBR promoted AMPK activity and fatty acid oxidation and changed expression of genes involved in lipid metabolism. Additionally, intracerebroventricular administration of BBR decreased the level of malonyl-CoA and stimulated the expression of fatty acid oxidation genes in skeletal muscle. Together, these data suggest that BBR would improve fatty liver in obese subjects, which is probably mediated not only by peripheral AMPK activation but also by neural signaling from the central nervous system.

scholarly journals The Effects of Ghrelin on Energy Balance and Psychomotor Activity in a Goldfish Model: An Overview

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ki Sung Kang ◽  
Satowa Yahashi ◽  
Kouhei Matsuda
Keyword(s):  
Energy Balance ◽  
Food Intake ◽  
Emotional Regulation ◽  
Energy Homeostasis ◽  
Biologically Active ◽  
Receptor System ◽  
Psychomotor Activity ◽  
Peripheral Tissues ◽  
Molecular Variants ◽  
Feeding Control

The goldfish (Carassius auratus) has a number of merits as a laboratory animal, and we have extensively identified the mechanisms by which ghrelin regulates food intake in this species. For the first time, we have purified and characterized 11 molecular variants of ghrelin that are present in goldfish intestine and shown that 17-residue ghrelin, the predominant form with n-octanoyl modification, is biologically active and implicated in the regulation of food intake as an endogenous orexigenic factor. Ghrelin and its receptor system are present not only in peripheral tissues such as stomach and intestine, but also in the central nervous system. Recent studies have also revealed that a number of neuropeptides are widely distributed in the brain in key areas of emotional regulation, and their role as modulators of behavioral states is being increasingly recognized. Interestingly, administration of ghrelin induces an orexigenic effect and also modifies locomotor activity, suggesting the involvement of ghrelin in feeding control and regulation of energy balance. Information derived from studies of ghrelin has been increasing, and important results have been obtained from both fish and mammals. Here, we present an overview of the effects of ghrelin on energy balance and psychomotor activity in the goldfish as an animal model. The available data provide an insight into evolutionary background of ghrelin's multiple actions on energy homeostasis in vertebrates.

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