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

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.

2018 ◽  
Vol 19 (11) ◽  
pp. 3552 ◽  
Author(s):  
Baile Wang ◽  
Kenneth Cheng

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
My Khanh Q. Huynh ◽  
Ann W. Kinyua ◽  
Dong Joo Yang ◽  
Ki Woo Kim

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.


2019 ◽  
Vol 62 (2) ◽  
pp. R129-R143 ◽  
Author(s):  
Chunmei Wang ◽  
Yong Xu

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.


2021 ◽  
Author(s):  
Angeliki M Angelidi ◽  
Matthew J Belanger ◽  
Alexander Kokkinos ◽  
Chrysi C Koliaki ◽  
Christos S Mantzoros

Abstract Recent insights into the pathophysiologic underlying mechanisms of obesity have led to the discovery of several promising drug targets and novel therapeutic strategies to address the global obesity epidemic and its comorbidities. Current pharmacologic options for obesity management are largely limited in number and of modest efficacy/safety profile. Therefore, the need for safe and more efficacious new agents is urgent. Drugs which are currently under investigation modulate targets across a broad range of systems and tissues, including the central nervous system, gastrointestinal hormones, adipose tissue, kidney, liver, and skeletal muscle. Beyond pharmacotherapeutics, other potential antiobesity strategies are being explored, including novel drug delivery systems, vaccines, modulation of the gut microbiome, and gene therapy. The present review summarizes the pathophysiology of energy homeostasis, and highlights pathways being explored in the effort to develop novel antiobesity medications and interventions but does not cover devices and bariatric methods. Emerging pharmacologic agents and alternative approaches targeting these pathways and relevant research in both animals and humans are presented in detail. Special emphasis is given to treatment options at the end of the development pipeline and closer to the clinic, i.e., compounds that have a higher chance to be added to our therapeutic armamentarium in the near future. Ultimately, advancements in our understanding of the pathophysiology and interindividual variation of obesity may lead to multimodal and personalized approaches to obesity treatment that will result in safe, effective and sustainable weight loss until the root causes of the problem are identified and addressed.


2009 ◽  
Vol 57 (1) ◽  
pp. 139-146
Author(s):  
Andrea Győrffy ◽  
Mónika Keresztes ◽  
Vera Faigl ◽  
Vilmos Frenyó ◽  
Margit Kulcsár ◽  
...  

In the regulation of energy metabolism, the liver plays an important role in the reinforcement of energy production. In periparturient cows the energy homeostasis turns into a negative energy balance that may shift the physiological regulation of energy balance towards pathological processes. Propylene glycol (PG), as a complementary source of energy used in the nutrition of dairy cows, alters systemic thyroid hormone economy; however, the exact mechanism through which highly glycogenic feed supplements impact liver metabolism is little known. Previous studies showed that only leptin receptors are expressed in the liver of cows, and now we report that leptin mRNA is expressed in the liver of cows as well. The present results show that the mRNA of leptin and its receptors are differentially modulated by the increased energy content of the feed consumed. Simultaneous changes in hepatic type I deiodinase activity suggest that hepatic modulation of the leptin system by PG supplementation may be mediated by an increased local thyroxine-triiodothyronine conversion. Since PG supplementation with simultaneous T4–T3 turnover and increased hepatic leptin- and short-form leptin receptor mRNA were not associated with a significant change in hepatic total lipid levels, it is suggested that the leptin system, directly or indirectly modulated by thyroid hormones, may represent a local defence mechanism to prevent fatty liver formation.


2017 ◽  
Vol 52 (3) ◽  
pp. 174
Author(s):  
Purwo Sri Rejeki ◽  
Harjanto Harjanto ◽  
Raden Argarini ◽  
Imam Subadi

The aim of this study was to determine the comparative effects of EA (EA) on the CV12, ST36 and ST40 to weight gain prevention over the short-term regulation of energy balance. The study was conducted with a completely randomized design. Rats were divided into five groups: negative control group (no treatment, n=5), positive control (sham EA/back, n=5), EA CV 12 (n=6), EA ST 36 (n=6) and EA ST 40 (n=7). Rats were exposed to high-fat diet for two weeks and EA was simultaneously performed once daily, five days a week for two weeks with 2 Hz, for 10 minutes with continuous wave. Body weight, BMI, front limb circumference and rear were measured during study. Levels of blood glucose, cholesterol, triglycerides, LDL and HDL were measured at the end of the study; which reflects the short-term regulation of energy homeostasis. For weight loss, EA CV12, ST36 and ST40 group have lost weight significantly compared to the negative and positive control group. The ST40 group has a significant decrease than ST36 and CV12. The most significant decrease in BMI found in the ST40 group. EA did not affect blood glucose levels, but modulated blood lipid profile. In ST 40 group there was a significant decrease in cholesterol, LDL and triglycerides. EA at point ST 40 is potential in preventing increased body weight and BMI in rats exposed to high-fat diet compared to the CV 12 and ST 36. ST 40 is a point with a potential of lowering LDL and triglycerides serum so that it can play a role in the short term regulation of energy homeostasis but also in the prevention of dyslipidemia.


2018 ◽  
Vol 15 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Liudmila I. Astafieva ◽  
Irina S. Klochkova ◽  
Pavel L. Kalinin ◽  
Boris A. Kadashev ◽  
Aleksandr N. Konovalov ◽  
...  

The key structure in the regulation of energy homeostasis is the hypothalamus. The damage of the hypothalamic region can lead to imbalance of energy exchange with the development of obesity or cachexia. The most common metabolic disorders occur in case of craniopharyngiomas. The article presents two clinical observations of papillary craniopharyngioma in young women. Cases were accompanied by different disturbances of the energy balance, in one - with the development of obesity, in the other - cachexia.


Diabetologia ◽  
2019 ◽  
Vol 63 (3) ◽  
pp. 453-461 ◽  
Author(s):  
Blandine Tramunt ◽  
Sarra Smati ◽  
Naia Grandgeorge ◽  
Françoise Lenfant ◽  
Jean-François Arnal ◽  
...  

AbstractGender and biological sex impact the pathogenesis of numerous diseases, including metabolic disorders such as diabetes. In most parts of the world, diabetes is more prevalent in men than in women, especially in middle-aged populations. In line with this, considering almost all animal models, males are more likely to develop obesity, insulin resistance and hyperglycaemia than females in response to nutritional challenges. As summarised in this review, it is now obvious that many aspects of energy balance and glucose metabolism are regulated differently in males and females and influence their predisposition to type 2 diabetes. During their reproductive life, women exhibit specificities in energy partitioning as compared with men, with carbohydrate and lipid utilisation as fuel sources that favour energy storage in subcutaneous adipose tissues and preserve them from visceral and ectopic fat accumulation. Insulin sensitivity is higher in women, who are also characterised by higher capacities for insulin secretion and incretin responses than men; although, these sex advantages all disappear when glucose tolerance deteriorates towards diabetes. Clinical and experimental observations evidence the protective actions of endogenous oestrogens, mainly through oestrogen receptor α activation in various tissues, including the brain, the liver, skeletal muscle, adipose tissue and pancreatic beta cells. However, beside sex steroids, underlying mechanisms need to be further investigated, especially the role of sex chromosomes, fetal/neonatal programming and epigenetic modifications. On the path to precision medicine, further deciphering sex-specific traits in energy balance and glucose homeostasis is indeed a priority topic to optimise individual approaches in type 2 diabetes prevention and treatment.


2020 ◽  
Vol 117 (41) ◽  
pp. 25818-25829
Author(s):  
Xinxing Wang ◽  
Hanxiao Liu ◽  
Johannes Morstein ◽  
Alexander J. E. Novak ◽  
Dirk Trauner ◽  
...  

Hippocampus-engaged behaviors stimulate neurogenesis in the adult dentate gyrus by largely unknown means. To explore the underlying mechanisms, we used tetrode recording to analyze neuronal activity in the dentate gyrus of freely moving adult mice during hippocampus-engaged contextual exploration. We found that exploration induced an overall sustained increase in inhibitory neuron activity that was concomitant with decreased excitatory neuron activity. A mathematical model based on energy homeostasis in the dentate gyrus showed that enhanced inhibition and decreased excitation resulted in a similar increase in neurogenesis to that observed experimentally. To mechanistically investigate this sustained inhibitory regulation, we performed metabolomic and lipidomic profiling of the hippocampus during exploration. We found sustainably increased signaling of sphingosine-1-phosphate, a bioactive metabolite, during exploration. Furthermore, we found that sphingosine-1-phosphate signaling through its receptor 2 increased interneuron activity and thus mediated exploration-induced neurogenesis. Taken together, our findings point to a behavior-metabolism circuit pathway through which experience regulates adult hippocampal neurogenesis.


2019 ◽  
Vol 115 (7/8) ◽  
Author(s):  
Gerald J. Maarman

A number of cardioprotective interventions have been identified throughout the years, and these include the use of natural antioxidants in sources like rooibos (Aspalathus linearis) tea. Recent studies have demonstrated that rooibos (either its isolated components or the crude rooibos extract/tea) confers cardioprotection in diabetic cardiomyopathy and myocardial ischaemic injury. In addition, a clinical study has shown that regular rooibos consumption reduces the risk for cardiovascular disease in adults. However, rooibos is currently not considered an official treatment against cardiac disease, mainly because the underlying mechanisms for rooibos-induced cardioprotection are not fully elucidated. Physiological actions of rooibos must be well investigated before rooibos can be used in a clinical setting as adjunct treatment for patients with heart disease. Thus, research to delineate the underlying mechanisms of rooibos-induced cardioprotection is key. In the light of the aforementioned, the available literature on rooibos-induced cardioprotection is reviewed here, highlighting the fact that rooibos preserves and maintains cardiac energy homeostasis. It is postulated that rooibos activates an AMPK-GLUT-4 glucose oxidation (cardiac energy-shortage sensing) pathway to shift cardiac energy usage, thereby conferring cardioprotection.


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