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Proceedings of the National Academy of... Aug 2023Hypothalamic inflammation reduces appetite and body weight during inflammatory diseases, while promoting weight gain when induced by high-fat diet (HFD). How...
Hypothalamic inflammation reduces appetite and body weight during inflammatory diseases, while promoting weight gain when induced by high-fat diet (HFD). How hypothalamic inflammation can induce opposite energy balance outcomes remains unclear. We found that prostaglandin E (PGE), a key hypothalamic inflammatory mediator of sickness, also mediates diet-induced obesity (DIO) by activating appetite-promoting melanin-concentrating hormone (MCH) neurons in the hypothalamus in rats and mice. The effect of PGE on MCH neurons is excitatory at low concentrations while inhibitory at high concentrations, indicating that these neurons can bidirectionally respond to varying levels of inflammation. During prolonged HFD, endogenous PGE depolarizes MCH neurons through an EP2 receptor-mediated inhibition of the electrogenic Na/K-ATPase. Disrupting this mechanism by genetic deletion of EP2 receptors on MCH neurons is protective against DIO and liver steatosis in male and female mice. Thus, an inflammatory mediator can directly stimulate appetite-promoting neurons to exacerbate DIO and fatty liver.
Topics: Mice; Rats; Male; Female; Animals; Obesity; Melanins; Hypothalamus; Inflammation; Fatty Liver; Diet, High-Fat; Neurons; Inflammation Mediators; Prostaglandins
PubMed: 37467285
DOI: 10.1073/pnas.2302809120 -
Appetite Jul 2024Nutritional status has clinical relevance and is a target of guidance to parents of children with cystic fibrosis (CF). Growth is routinely monitored in CF clinics but...
Nutritional status has clinical relevance and is a target of guidance to parents of children with cystic fibrosis (CF). Growth is routinely monitored in CF clinics but there is no standardized way of assessing appetitive behaviors or parents' perceptions of their children's appetite. Greater understanding of these factors could improve clinical guidance regarding parent feeding behaviors. We therefore aimed to assess parent perceptions of child weight, and parent reports of child appetite using the Baby Eating Behavior Questionnaire (BEBQ), in a sample of infants and toddlers with CF, compared with a community sample. We additionally assessed relationships of parent perceptions of child weight with parent feeding behaviors in the sample with CF. Anthropometric and questionnaire data were collected for 32 infants and toddlers with CF, as well as 193 infants and toddlers drawn from RESONANCE, a community cohort study. Parents perceived children with CF to be lower in weight than their actual weight, to a greater extent than was evident in the community sample. Parents who perceived their children with CF to be underweight vs. right weight reported greater slowness in eating on the BEBQ. Parents perceived children with CF to have greater slowness in eating and lower enjoyment of food, compared to parents of children in the community sample, independent of sample differences in child weight, age, and sex. Our results demonstrate the potential utility of the BEBQ in a clinical sample and suggest it may be helpful for clinicians to assess parents' perceptions of their child's weight and appetite to promote a fuller understanding of the child's nutritional status, facilitate appropriate feeding behaviors and alleviate unnecessary concerns.
Topics: Humans; Cystic Fibrosis; Male; Female; Infant; Body Weight; Parents; Appetite; Feeding Behavior; Surveys and Questionnaires; Child, Preschool; Nutritional Status; Perception; Thinness; Cohort Studies
PubMed: 38621592
DOI: 10.1016/j.appet.2024.107357 -
Physiology & Behavior Sep 2023Dysfunctional signaling in midbrain reward circuits perpetuates diseases characterized by compulsive overconsumption of rewarding substances such as substance abuse,... (Review)
Review
Dysfunctional signaling in midbrain reward circuits perpetuates diseases characterized by compulsive overconsumption of rewarding substances such as substance abuse, binge eating disorder, and obesity. Ventral tegmental area (VTA) dopaminergic activity serves as an index for how rewarding stimuli are perceived and triggers behaviors necessary to obtain future rewards. The evolutionary linking of reward with seeking and consuming palatable foods ensured an organism's survival, and hormone systems that regulate appetite concomitantly developed to regulate motivated behaviors. Today, these same mechanisms serve to regulate reward-directed behavior around food, drugs, alcohol, and social interactions. Understanding how hormonal regulation of VTA dopaminergic output alters motivated behaviors is essential to leveraging therapeutics that target these hormone systems to treat addiction and disordered eating. This review will outline our current understanding of the mechanisms underlying VTA action of the metabolic hormones ghrelin, glucagon-like peptide-1, amylin, leptin, and insulin to regulate behavior around food and drugs of abuse, highlighting commonalities and differences in how these five hormones ultimately modulate VTA dopamine signaling.
Topics: Humans; Ventral Tegmental Area; Signal Transduction; Appetite; Obesity; Dopamine; Reward
PubMed: 37178855
DOI: 10.1016/j.physbeh.2023.114236 -
EBioMedicine Jan 2024Food is crucial for maintaining vital human and animal activities. Disorders in appetite control can lead to various metabolic disturbances. Alterations in the gut...
BACKGROUND
Food is crucial for maintaining vital human and animal activities. Disorders in appetite control can lead to various metabolic disturbances. Alterations in the gut microbial composition can affect appetite and energy metabolism. While alterations in the gut microbiota have been observed in high-temperature and high-humidity (HTH) environments, the relationship between the gut microbiota during HTH and appetite remains unclear.
METHODS
We utilised an artificial climate box to mimic HTH environments, and established a faecal bacteria transplantation (FMT) mouse model. Mendelian randomisation (MR) analysis was used to further confirm the causal relationship between gut microbiota and appetite or appetite-related hormones.
FINDINGS
We found that, in the eighth week of exposure to HTH environments, mice showed a decrease in food intake and body weight, and there were significant changes in the intestinal microbiota compared to the control group. After FMT, we observed similar changes in food intake, body weight, and gut bacteria. Appetite-related hormones, including ghrelin, glucagon-like peptide-1, and insulin, were reduced in DH (mice exposed to HTH conditions) and DHF (FMT from mice exposed to HTH environments for 8 weeks), while the level of peptide YY initially increased and then decreased in DH and increased after FMT. Moreover, MR analysis further confirmed that these changes in the intestinal microbiota could affect appetite or appetite-related hormones.
INTERPRETATION
Together, our data suggest that the gut microbiota is closely associated with appetite suppression in HTH. These findings provide novel insights into the effects of HTH on appetite.
FUNDING
This work was supported by the National Natural Science Foundation of China and Guangzhou University of Chinese Medicine.
Topics: Humans; Animals; Mice; Gastrointestinal Microbiome; Appetite; Humidity; Temperature; Body Weight
PubMed: 38103514
DOI: 10.1016/j.ebiom.2023.104918 -
Appetite Nov 2023It is often suggested in the popular press that food chains deliberately introduce enticing product aromas into (and in the immediate vicinity of) their premises in... (Review)
Review
It is often suggested in the popular press that food chains deliberately introduce enticing product aromas into (and in the immediate vicinity of) their premises in order to attract customers. However, despite the widespread use of odours in the field of sensory marketing, laboratory research suggests that their effectiveness in modulating people's food behaviours depends on a range of contextual factors. Given the evidence that has been published to date, only under a subset of conditions is there likely to be a measurable effect of the presence of ambient odours on people's food attitudes and choices. This narrative historical review summarizes the various ways in which food odours appear to bias people's food preferences (appetite) and food choices (food consumption and purchase). Emphasis is placed on those experimental studies that have been designed to investigate how the characteristics of the olfactory stimuli (e.g., the congruency between the olfactory cues and the foods, intensity and duration of exposure to odours, and taste properties of odours) modulate the effects of olfactory cues on food behaviour. The review also explores the moderating roles of individual differences, such as dietary restraint, Body Mass Index (BMI), genetic and cultural differences in odour sensitivity and perception. Ultimately, following a review of empirical studies on food-related olfaction, current approaches in scent marketing are discussed and a research agenda is proposed to help encourage further studies on the effective application of scents in promoting healthy foods.
Topics: Humans; Smell; Taste; Food; Taste Perception; Odorants
PubMed: 37673129
DOI: 10.1016/j.appet.2023.107023 -
Food and Chemical Toxicology : An... Sep 2023The presence of anorexia in animals is the most well-known clinical symptom of T-2 toxin poisoning. T-2 toxin is the most characteristic type A toxin in the... (Review)
Review
The presence of anorexia in animals is the most well-known clinical symptom of T-2 toxin poisoning. T-2 toxin is the most characteristic type A toxin in the trichothecene mycotoxins. The consumption of T-2 toxin can cause anorexic response in mice, rats, rabbits, and other animals. In this review, the basic information of T-2 toxin, appetite regulation mechanism and the molecular mechanism of T-2 toxin-induced anorectic response in animals are presented and discussed. The objective of this overview is to describe the research progress of anorexia in animals produced by T-2 toxin. T-2 toxin mainly causes antifeedant reaction through four pathways: vagus nerve, gastrointestinal hormone, neurotransmitter and cytokine. This review aims to give an academic basis and useable reference for the prevention and treatment of clinical symptoms of anorexia in animals resulting from T-2 toxin.
Topics: Mice; Rats; Animals; Rabbits; T-2 Toxin; Anorexia; Appetite Depressants; Mycotoxins; Neurotransmitter Agents
PubMed: 37553049
DOI: 10.1016/j.fct.2023.113982 -
Nature Communications Sep 2023GPR61 is an orphan GPCR related to biogenic amine receptors. Its association with phenotypes relating to appetite makes it of interest as a druggable target to treat...
GPR61 is an orphan GPCR related to biogenic amine receptors. Its association with phenotypes relating to appetite makes it of interest as a druggable target to treat disorders of metabolism and body weight, such as obesity and cachexia. To date, the lack of structural information or a known biological ligand or tool compound has hindered comprehensive efforts to study GPR61 structure and function. Here, we report a structural characterization of GPR61, in both its active-like complex with heterotrimeric G protein and in its inactive state. Moreover, we report the discovery of a potent and selective small-molecule inverse agonist against GPR61 and structural elucidation of its allosteric binding site and mode of action. These findings offer mechanistic insights into an orphan GPCR while providing both a structural framework and tool compound to support further studies of GPR61 function and modulation.
Topics: Allosteric Site; Appetite; Binding Sites; Drug Inverse Agonism; GTP-Binding Proteins; Humans; Receptors, G-Protein-Coupled
PubMed: 37741852
DOI: 10.1038/s41467-023-41646-3 -
JAMA Feb 2024
Topics: Food; Appetite; Diet; Feeding Behavior
PubMed: 38411654
DOI: 10.1001/jama.2023.18213 -
Hormones and Behavior Apr 2024This review addresses the translational relevance of animal models of stress and their effects on body weight. In humans, stress, whether chronic or acute, has often... (Review)
Review
This review addresses the translational relevance of animal models of stress and their effects on body weight. In humans, stress, whether chronic or acute, has often been associated with increased food intake and weight gain. In view of the current obesity epidemic, this phenomenon is especially relevant. Such observations contrast with reports with commonly used laboratory animals, especially rats and mice. In these species, it is common to find individuals gaining less weight under stress, even with potent social stressors. However, there are laboratory species that present increased appetite and weight gain under stress, such as golden hamsters. Furthermore, these animals also include metabolic and behavioral similarities with humans, including hoarding behavior which is also enhanced under stress. Consequently, we propose that our comparative perspective provides useful insights for future research on the development of obesity in humans as a consequence of chronic stress exposure.
Topics: Animals; Cricetinae; Mice; Rats; Appetite; Body Weight; Eating; Mesocricetus; Obesity; Weight Gain; Disease Models, Animal
PubMed: 38306877
DOI: 10.1016/j.yhbeh.2024.105488