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Nature Communications Jun 2024Pyroglutamylated RF-amide peptide (QRFP) is a peptide hormone with a C-terminal RF-amide motif. QRFP selectively activates a class A G-protein-coupled receptor (GPCR)...
Pyroglutamylated RF-amide peptide (QRFP) is a peptide hormone with a C-terminal RF-amide motif. QRFP selectively activates a class A G-protein-coupled receptor (GPCR) GPR103 to exert various physiological functions such as energy metabolism and appetite regulation. Here, we report the cryo-electron microscopy structure of the QRFP26-GPR103-G complex at 3.19 Å resolution. QRFP26 adopts an extended structure bearing no secondary structure, with its N-terminal and C-terminal sides recognized by extracellular and transmembrane domains of GPR103 respectively. This movement, reminiscent of class B1 GPCRs except for orientation and structure of the ligand, is critical for the high-affinity binding and receptor specificity of QRFP26. Mutagenesis experiments validate the functional importance of the binding mode of QRFP26 by GPR103. Structural comparisons with closely related receptors, including RY-amide peptide-recognizing GPCRs, revealed conserved and diversified peptide recognition mechanisms, providing profound insights into the biological significance of RF-amide peptides. Collectively, this study not only advances our understanding of GPCR-ligand interactions, but also paves the way for the development of novel therapeutics targeting metabolic and appetite disorders and emergency medical care.
Topics: Receptors, G-Protein-Coupled; Humans; Cryoelectron Microscopy; HEK293 Cells; Protein Binding; Ligands; Intercellular Signaling Peptides and Proteins
PubMed: 38897996
DOI: 10.1038/s41467-024-49030-5 -
Ecotoxicology and Environmental Safety Jun 2024T-2 toxin is one of trichothecene mycotoxins, which can impair appetite and decrease food intake. However, the specific mechanisms for T-2 toxin-induced anorexia are not...
T-2 toxin is one of trichothecene mycotoxins, which can impair appetite and decrease food intake. However, the specific mechanisms for T-2 toxin-induced anorexia are not fully clarified. Multiple research results had shown that gut microbiota have a significant effect on appetite regulation. Hence, this study purposed to explore the potential interactions of the gut microbiota and appetite regulate factors in anorexia induced by T-2 toxin. The study divided the mice into control group (CG, 0 mg/kg BW T-2 toxin) and T-2 toxin-treated group (TG, 1 mg/kg BW T-2 toxin), which oral gavage for 4 weeks, to construct a subacute T-2 toxin poisoning mouse model. This data proved that T-2 toxin was able to induce an anorexia in mice by increased the contents of gastrointestinal hormones (CCK, GIP, GLP-1 and PYY), neurotransmitters (5-HT and SP), as well as pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) in serum of mice. T-2 toxin disturbed the composition of gut microbiota, especially, Faecalibaculum and Allobaculum, which was positively correlated with CCK, GLP-1, 5-HT, IL-1β, IL-6 and TNF-α, which played a certain role in regulating host appetite. In conclusion, gut microbiota changes (especially an increase in the abundance of Faecalibaculum and Allobaculum) promote the upregulation of gastrointestinal hormones, neurotransmitters, and pro-inflammatory cytokines, which may be a potential mechanism of T-2 toxin-induced anorexia.
PubMed: 38896898
DOI: 10.1016/j.ecoenv.2024.116612 -
Nutrients May 2024The gut microbiota plays a crucial role in postnatal growth, particularly in modulating the development of animals during their growth phase. In this study, we...
The gut microbiota plays a crucial role in postnatal growth, particularly in modulating the development of animals during their growth phase. In this study, we investigated the effects of antibiotic-induced dysbiosis of the gut microbiota on the growth of weaning rats by administering a non-absorbable antibiotic cocktail (ABX) in water for 4 weeks. ABX treatment significantly reduced body weight and feed intake in rats. Concurrently, ABX treatment decreased microbial abundance and diversity in rat ceca, predominantly suppressing microbes associated with bile salt hydrolase (BSH) activity. Furthermore, decreased appetite may be attributed to elevated levels of glucagon-like peptide-1 (GLP-1) in the serum, along with reduced neuropeptide Y (NPY) and increased cocaine and amphetamine-regulated transcript (CART) in the hypothalamus at the mRNA level. Importantly, concentrations of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor 2 (IGF-2) were decreased in the serum and liver of antibiotic-treated rats. These alterations were associated with significant down-regulation of IGF-2 mRNA in the liver and significantly decreased farnesoid X receptor (FXR) protein expression and binding to the IGF-2 promoter. These results indicate that antibiotic-induced gut microbial dysbiosis not only impacts bile acid metabolism but also diminishes rat growth through the FXR-mediated IGF-2 pathway.
Topics: Animals; Gastrointestinal Microbiome; Dysbiosis; Receptors, Cytoplasmic and Nuclear; Liver; Anti-Bacterial Agents; Weaning; Rats; Male; Insulin-Like Growth Factor II; Rats, Sprague-Dawley; Body Weight
PubMed: 38892577
DOI: 10.3390/nu16111644 -
Scientific Reports Jun 2024Body weight is related to both diabetes and cognitive impairment; however, the associations between body mass index (BMI) and cognitive impairment have been reported...
Body weight is related to both diabetes and cognitive impairment; however, the associations between body mass index (BMI) and cognitive impairment have been reported less frequently among diabetes patients. A total of 1355 patients with type 2 diabetes aged ≥ 60 years were included in this study. The Montreal Cognitive Assessment (MoCA) was administered to assess participants' cognitive status. We collected self-reported body weight, weight loss and appetite loss data using questionnaires. Associations between body weight status (in childhood, midlife age, and late life), weight loss, appetite changes and cognitive impairment were explored using logistic regression. Among the participants, 41.7% exhibited cognitive impairment. Overweight in childhood and late life was associated with cognitive impairment among diabetes patients (OR 2.63, 95% CI 1.52-4.55; OR 1.32, 95% CI 1.03-1.69). Diabetes patients with cognitive impairment were more likely to report a body weight decline and appetite reduction in the past three months (OR 4.18, 95% CI 2.61-6.71; OR 4.41, 95% CI 2.67-7.29). Higher BMI, weight loss, and appetite reduction were positively correlated with cognitive impairment. Given the risk of cognitive impairment, we suggest that body weight and BMI decline should be monitored in patients with diabetes.
Topics: Humans; Male; Body Mass Index; Female; Cognitive Dysfunction; Aged; Diabetes Mellitus, Type 2; Weight Loss; Middle Aged; Body Weight; Aged, 80 and over; Appetite Regulation; Appetite
PubMed: 38890509
DOI: 10.1038/s41598-024-65005-4 -
British Journal of Pharmacology Jun 2024The cannabinoid CB receptor has a well-established role in appetite regulation. Drugs antagonizing central CB receptors, most notably rimonabant, induced weight loss and...
BACKGROUND AND PURPOSE
The cannabinoid CB receptor has a well-established role in appetite regulation. Drugs antagonizing central CB receptors, most notably rimonabant, induced weight loss and improved the metabolic profile in obese individuals but were discontinued due to psychiatric side effects. However, metabolic benefits were only partially attributable to weight loss, implying a role for peripheral receptors, and peripherally restricted CB receptor antagonists have since been of interest. Herein, we describe the evaluation of the peripherally restricted potent CB receptor inverse agonists TM38837 and TM39875, with acidic functionality, which were administered daily to diet-induced obese (DIO) mice for 5 weeks at doses for which CNS-mediated effects were minimal.
EXPERIMENTAL APPROACH
Compounds were tested in dose-response in acute studies to compare efficacy (gastric transport) and extent of CNS exposure (hypothermia and satiety sequence) to demonstrate peripheral restriction and select doses for the subsequent chronic DIO study.
KEY RESULTS
TM38837 but not TM39875 produced considerable (26%) weight loss, linked to a sustained reduction in food intake, together with improvements in plasma markers of inflammation and glucose homeostasis. Pharmacokinetic analysis indicated high plasma and low brain levels for both compounds with high liver levels for TM38837 (but not TM39875) due to hepatic uptake.
CONCLUSION AND IMPLICATIONS
Weight loss and metabolic benefits of TM38837 are likely not CNS-mediated but could be linked to enhanced liver exposure, which implicates intracellular CB receptors in hepatocytes as a possible driver of obesity and co-morbidities.
PubMed: 38886096
DOI: 10.1111/bph.16401 -
SAGE Open Medicine 2024Dolutegravir is an integrase inhibitor and is recommended by the World Health Organization as the preferred first-line and second-line human immunodeficiency virus... (Review)
Review
Dolutegravir is an integrase inhibitor and is recommended by the World Health Organization as the preferred first-line and second-line human immunodeficiency virus treatment in all populations. Excessive weight gain associated with dolutegravir-based regimens is an emerging issue; however, the long-term metabolic consequences of this effect have not been fully understood. Growing evidence shows that this leads to a higher incidence of hyperglycemia, hypertension, and metabolic syndrome, along with elevated cardiovascular risk. Dolutegravir-based regimens, also associated with greater adipocyte differentiation and greater expression of markers associated with lipid storage, continue to be a problem among patients living with human immunodeficiency virus. The mechanisms by which certain antiretroviral therapy agents differentially contribute to weight gain remain unknown. Some clinical investigators speculate that dolutegravir could interfere with central nervous system appetite regulation (melanocortin-4 receptor) and insulin signaling, or may have better penetration of adipose tissue where they could exert a direct impact on adipose tissue adipogenesis, fibrosis, and insulin resistance. This review summarizes our current understanding of weight gain and fat changes associated with dolutegravir and its possible secondary metabolic comorbidities.
PubMed: 38881592
DOI: 10.1177/20503121241260613 -
Journal of Chromatography. B,... Jun 2024The use of semaglutide, also known by its trade name Ozempic®, has been increasing worldwide in recent years due to its benefits in treating type II diabetes. Thanks to...
The use of semaglutide, also known by its trade name Ozempic®, has been increasing worldwide in recent years due to its benefits in treating type II diabetes. Thanks to its effects on appetite regulation, in many countries it is also used to treat obesity. However, due to its promotion by social media and celebrities as a weight-loss treatment, semaglutide is misused by a non-diabetic and non-obese population and by a young public, which is the main target of these media. Following the alert by the ANSM (Agence nationale de sécurité du médicament) in France and the FDA (Food and Drug Administration) in the United States, which imposed the addition of fatal effects to the list of side effects, the misuse of semaglutide seems to be becoming a public health problem. For this reason, it seems important that a toxicology laboratory has the capacity to test for semaglutide in blood. In this study, the authors have developed and validated a method for the identification and quantification of semaglutide in whole blood using a LC-HRMS. After the addition of the internal standard (bovine insulin), the blood was subjected to protein precipitation using a mix of acetonitrile/methanol (70:30,v:v). The validation procedure demonstrated an acceptable linearity between 2 and 500 ng/mL. LOD and LOQ were 1 and 2 ng/mL, respectively. Intra and inter-day precision were below 20 % at three concentrations. The method was successfully applied to the blood samples of 3 diabetic patients under treatment of semaglutide. The samples tested positive with concentrations ranging from 31 to 70 ng/mL which fall within the limits of therapeutic blood concentrations described in the literature.
PubMed: 38880054
DOI: 10.1016/j.jchromb.2024.124187 -
Clinical Nutrition (Edinburgh, Scotland) Jun 2024The aging process is often accompanied by high risk of malnutrition and elevated levels of growth differentiation factor 15 (GDF15). GDF15 is an increasingly recognized...
BACKGROUND AND AIMS
The aging process is often accompanied by high risk of malnutrition and elevated levels of growth differentiation factor 15 (GDF15). GDF15 is an increasingly recognized biomarker for regulation of metabolism, but few studies have investigated the connection between GDF15 and malnutrition in older age and how it relates to other features of aging such as decreased appetite and physical function. Therefore, we investigated the associations between GDF15 levels and nutritional status, appetite, and physical function in acutely admitted older adults.
METHODS
Plasma GDF15 levels were measured using immunoassays in 302 older adults (≥65 years) admitted to the emergency department (ED). Nutritional status was evaluated with the Mini Nutritional Assessment Short-Form (MNA®-SF), appetite was evaluated with the Simplified Nutritional Appetite Questionnaire (SNAQ), and physical function was evaluated with handgrip strength (HGS), 30-s chair stand test (30s-RSS), and gait speed (GS). Associations between GDF15 and each outcome was determined by logistic regression adjusted for age, sex, and C-reactive protein (CRP).
RESULTS
Each doubling in plasma GDF15 level was associated with an adjusted odds ratio (OR) (95% confidence interval) of 1.59 (1.10-2.29, P = 0.01) for risk of malnutrition compared to normal nutrition and 1.19 (0.85-1.69, P = 0.3)) for malnutrition compared to risk of malnutrition. Each doubling in GDF15 was associated with an adjusted OR of 1.63 (1.21-2.23)) for having poor appetite, 1.46 (1.07-1.99) for having low HGS, 1.74 (1.23-2.51) for having low 30s-RSS, and 1.99 (1.39-2.94) for having low GS.
CONCLUSION
Among older adults admitted to the ED, higher GDF15 levels were significantly associated with malnutrition, poor appetite, and low physical function independent of age, sex, and CRP.
PubMed: 38879915
DOI: 10.1016/j.clnu.2024.06.005 -
Analytical Methods : Advancing Methods... Jun 2024Methyl parathion, a highly toxic, efficient, and persistent organophosphorus pesticide, is widely used in China. Sibutramine, a non-amphetamine central nervous system...
Methyl parathion, a highly toxic, efficient, and persistent organophosphorus pesticide, is widely used in China. Sibutramine, a non-amphetamine central nervous system depressant, helps lose weight by disrupting hormone regulation, stimulating sympathetic nerves, and suppressing appetite. However, some unethical businesses fail to properly handle raw materials in foods like apple cider vinegar, leading to residual methyl parathion in apples or illegal excessive addition of sibutramine. Therefore, it is imperative to develop an immunoassay for the rapid detection of methyl parathion and sibutramine. The corresponding two haptens were prepared and coupled with the carrier proteins according to methyl parathion-sulfur-bovine serum protein (BSA)/chicken ovalbumin (OVA)-sibutramine (20 : 1 : excess, 15 : 1 : excess, 10 : 1 : excess, and 5 : 1 : excess), and sibutramine-BSA/OVA-methyl parathion (20 : 1 : excess, 10 : 1 : excess: 5 : 1 : excess, and 0 : 1 : excess). The result shows that the inhibition rate of the antibody obtained by methyl parathion-BSA/OVA-sibutramine (20 : 1 : excess) was higher than that of sibutramine-BSA/OVA-methyl parathion, which was 67.93%, and the concentration of methyl parathion was 8.65 ng mL at this inhibition rate. Thus, methyl parathion-BSA/OVA-sibutramine (8.65 : 1 : excess) and the corresponding antibodies were selected for subsequent method establishment. By changing the concentration of the coating and antibody, the inhibition rate was found when the coating was 0.125 ng mL and the antibody was diluted 4000 times. The antibody was used to develop a standard curve for the detection of sibutramine at the half-maximum inhibitory concentration (IC) is 4.59 ng mL, the limit of detection (IC) is 2.21 ng mL, the detection range is 2.89 to 7.28 ng mL, methyl p-phosphorus at the half-maximum inhibitory concentration (IC) is 15.34 ng mL, the limit of detection (IC) is 0.42 ng mL, the detection range is ng mL. Under these conditions, the recovery rate was between 88% and 102%, within reasonable limits, indicating the successful establishment of a rapid enzyme-linked ELISA assay.
Topics: Cyclobutanes; Enzyme-Linked Immunosorbent Assay; Malus; Methyl Parathion; Acetic Acid; Appetite Depressants; Food Contamination; Animals; Limit of Detection
PubMed: 38873980
DOI: 10.1039/d4ay00879k -
Journal of Pharmacy & Pharmaceutical... 2024Childhood obesity has emerged as a major global health issue, contributing to the increased prevalence of chronic conditions and adversely affecting the quality of life... (Review)
Review
Childhood obesity has emerged as a major global health issue, contributing to the increased prevalence of chronic conditions and adversely affecting the quality of life and future prospects of affected individuals, thereby presenting a substantial societal challenge. This complex condition, influenced by the interplay of genetic predispositions and environmental factors, is characterized by excessive energy intake due to uncontrolled appetite regulation and a Westernized diet. Managing obesity in childhood requires specific considerations compared with adulthood, given the vulnerability of the critical juvenile-adolescent period to toxicity and developmental defects. Consequently, common treatment options for adult obesity may not directly apply to younger populations. Therefore, research on childhood obesity has focused on genetic defects in regulating energy intake, alongside pharmacotherapy and dietary interventions as management approaches, with an emphasis on safety concerns. This review aims to summarize canonical knowledge and recent findings on genetic factors contributing to childhood obesity. Additionally, it assesses the efficacy and safety of existing pharmacotherapies and dietary interventions and suggests future research directions. By providing a comprehensive understanding of the complex dynamics of childhood obesity, this review aims to offer insights into more targeted and effective strategies for addressing this condition, including personalized healthcare solutions.
Topics: Humans; Pediatric Obesity; Child; Anti-Obesity Agents; Diet
PubMed: 38863827
DOI: 10.3389/jpps.2024.12861