This study investigates the relationships between melanocortin-4 receptor (MC4R) rs17782313 gene polymorphisms, low-fat diet, aerobic exercise, and the reduction in blood lipid levels in individuals w Show more
This study investigates the relationships between melanocortin-4 receptor (MC4R) rs17782313 gene polymorphisms, low-fat diet, aerobic exercise, and the reduction in blood lipid levels in individuals with obesity. A total of 240 adults living with obesity were enrolled to take part in a 12-week program that combined exercises with dietary interventions. Measurements taken included body weight, body mass index (BMI), plasma lipids, fasting insulin (FIN), and insulin resistance (Homeostasis Model Assessment, HOMA-IR). All participants underwent exercise intervention and genotyping. Our findings revealed significant interactions between genotype, sex, and diet in modulating lipid metabolism. Specifically, after the exercise intervention, the mean reduction in BMI in was: CC+CT with low-fat diet: -2.56 ± 1.98 kg/m The CC+CT genotype group, particularly males on a low-fat diet, showed robust improvements in TG, LDL-C, and insulin resistance markers. However, HDL-C responses were inconsistent across subgroups. Notably, males with the CC+CT allele exhibited the most pronounced benefits in LDL-C reduction and HOMA-IR improvement with a low-fat diet. Show less
The internal milieu of the body is controlled by a system of interoceptors coupled to motor outflows that drive compensatory adaptive responses. These include the arterial chemoreceptors, best known f Show more
The internal milieu of the body is controlled by a system of interoceptors coupled to motor outflows that drive compensatory adaptive responses. These include the arterial chemoreceptors, best known for sensing arterial oxygen. In cardiometabolic diseases, such as essential hypertension, the carotid bodies (CB) exhibit heightened reflex sensitivity and tonic activity without an apparent stimulus. The mechanisms behind CB sensitization in these conditions are not well understood. Guided by functional genomics, a range of functional assays is used to interrogate downstream intracellular and interorgan signaling pathways involved in arterial chemosensory function. Here, we report the presence of the MC4R (melanocortin 4 receptor) in the mammalian CB and show its elevated expression in experimental hypertension. We demonstrate that melanocortin agonists activate arterial chemosensory cells, modulating CB chemosensory afferent drive to influence chemoreflex-evoked sympathetic and ventilatory activity. Transcriptional analysis of hypertensive CB implicates the activation of the Mash1 (mammalian achaete-scute homolog 1; Collectively, our data indicate a primarily pathophysiological role of melanocortin signaling in arterial chemosensation, contributing to excess sympathetic activity in cardiometabolic disease. Show less
Obesity is a global health challenge marked by substantial inter-individual differences in responses to dietary and lifestyle interventions. Traditional weight loss strategies often overlook critical Show more
Obesity is a global health challenge marked by substantial inter-individual differences in responses to dietary and lifestyle interventions. Traditional weight loss strategies often overlook critical biological variations in genetics, metabolic profiles, and gut microbiota composition, contributing to poor adherence and variable outcomes. Our primary aim is to identify key biological and behavioral effectors relevant to precision medicine for weight control, with a particular focus on nutrition, while also discussing their current and potential integration into digital health platforms. Thus, this review aligns more closely with the identification of influential factors within precision medicine (e.g., genetic, metabolic, and microbiome factors) but also explores how these factors are currently integrated into digital health tools. We synthesize recent advances in nutrigenomics, nutritional metabolomics, and microbiome-informed nutrition, highlighting how tailored dietary strategies-such as high-protein, low-glycemic, polyphenol-enriched, and fiber-based diets-can be aligned with specific genetic variants (e.g., FTO and MC4R), metabolic phenotypes (e.g., insulin resistance), and gut microbiota profiles (e.g., Show less
Rajae Talbi, Todd L Stincic, Nicole Lynch+14 more · 2025 · bioRxiv : the preprint server for biology · Cold Spring Harbor Laboratory · added 2026-04-24
Energy expenditure (EE) is essential for metabolic homeostasis, yet its central regulation remains poorly understood. Here, we identify arcuate Kiss1 neurons as key regulators of EE in male mice. Abla Show more
Energy expenditure (EE) is essential for metabolic homeostasis, yet its central regulation remains poorly understood. Here, we identify arcuate Kiss1 neurons as key regulators of EE in male mice. Ablation of these neurons induced obesity, while their chemogenetic activation increased brown adipose tissue (BAT) thermogenesis without affecting food intake. This action is mediated by glutamatergic projections from Kiss1 Show less
Food addiction (FA) has gained more scientific attention but needs deeper understanding. Data indicates that the central melanocortin (MC) system through the MC4 receptor (MC4R) and its polymorphisms Show more
Food addiction (FA) has gained more scientific attention but needs deeper understanding. Data indicates that the central melanocortin (MC) system through the MC4 receptor (MC4R) and its polymorphisms play a crucial role in the regulation of eating behaviour and in the motivation for the rewarding properties of food potentially leading to obesity. This may also contribute to the emergence of altered reward-related behaviors such as FA. The study aims to evaluate the genetic contribution of rs17782313, rs12970134, rs10871777, rs6567160, rs17700144 MC4R polymorphisms to the development of FA and to assess the association between these MC4R variations and clinical features. Eating (EDE-Q, BES, NEQ, GQ) and general psychopathology (BDI-II, STAI-S, DERS) were evaluated in patients with obesity with and without FA. Y-FAS 2.0 was used to assess FA. A blood sample was collected from all patients for the genotyping of MC4R polymorphisms. All the polymorphisms were equally distributed between groups except for rs17782313. A direct association between rs17782313 with FA was evident. Patients with FA and with C allele showed higher risk of FA compared to group without FA. There was a significant effect of rs17782313 on psychopathological variables in patients with FA. Allele C carriers exhibited higher anxiety and depression than T carriers. The rs17782313 of the MC4R showed an association with FA. A significant direct influence of C allele on anxiety and depression emerged in the group with FA but not in patients without FA. Show less
Cardiovascular diseases (CVDs), including myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), and arrhythmia, are major contributors to global mortality and often share overlappi Show more
Cardiovascular diseases (CVDs), including myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), and arrhythmia, are major contributors to global mortality and often share overlapping risk factors and pathophysiological mechanisms. While genome-wide association studies (GWAS) have identified many loci for individual CVDs, the shared genetic architecture across related traits-particularly in East Asian populations-remains underexplored. We integrated large-scale GWAS summary statistics from East Asian populations to perform genome-wide and local genetic correlation analyses across four CVD phenotypes and five cardiometabolic traits (blood pressure and lipid levels). Using stratified LD score regression, we assessed tissue-specific heritability enrichment. Multi-trait analysis of GWAS (MTAG) was then employed to identify pleiotropic loci associated with multiple traits, with functional annotation and expression quantitative trait loci (eQTL) data used to explore biological relevance. We observed extensive genetic correlations among CVDs and between CVDs and cardiometabolic traits, with HF showing the strongest connections to both MI and arrhythmia. Notable genome-wide correlations were found between MI and SBP (rg = 0.35, Our findings provide comprehensive insight into the shared genetic determinants of cardiovascular and metabolic diseases in East Asian populations. The identification of pleiotropic and ancestry-specific loci, along with tissue-specific regulatory patterns, underscores the need for integrative multi-trait and population-informed approaches in cardiovascular genetics and risk prediction. Show less
The melanocortin receptor 4 (MC4R) plays a key role in the CNS regulation of metabolism. In addition to its role within the hypothalamus, other brain areas, including the dorsal raphe nucleus (DRN), e Show more
The melanocortin receptor 4 (MC4R) plays a key role in the CNS regulation of metabolism. In addition to its role within the hypothalamus, other brain areas, including the dorsal raphe nucleus (DRN), express MC4R. However, the identity and role of these neurons in metabolism regulation are not fully understood. We performed studies to address these questions. We generated Mc4r-cre;Vgat-FlpO and Mc4r-cre;Vglut2-FlpO mice to determine the contribution of these MC4R neuronal populations in DRN. We then chemogenetically activated or inhibited the GABAergic and glutamatergic populations of MC4R. Finally, we selectively deleted MC4R from these two neuronal populations and studied the impact on whole-body metabolism. We found that about 60% of DRN MC4R neurons are GABAergic (Vgat), while only about 20% are glutamatergic (Vglut2). Most of the projections onto DRN neurons originated from the arcuate nucleus (ARC)-POMC neurons, and only a small input from the nucleus of the solitary tract (NTS)-POMC neurons was identified. Significant projections of DRN MC4R/Vgat neurons were observed in the paraventricular nucleus of the hypothalamus (PVN). Chemogenetic activation or inhibition of MC4R/Vgat neurons increased or inhibited food intake, respectively. No effects were observed when the same approach was used in MC4R/Vglut2 neurons. Furthermore, only chemogenetic manipulation of the MC4R/Vgat neurons affected anxiety-like behavior, which was associated with changes in serotonin staining in the DRN. Finally, MC4R-selective deletion in Vgat but not Vglut2 neurons affected whole-body metabolism. These findings suggest that DRN MC4R/Vgat neurons receiving projections from the ARC POMC neurons and projecting to the hypothalamic PVN play a role in metabolism regulation. In addition, this same DRN neuronal subpopulation affects anxiety-like behavior by modulating DRN serotonin neurons. Show less
Introduction: Pathogenic heterozygous melanocortin-4 receptor (MC4R) variants are the most common cause of monogenic obesity, affecting central satiety and appetite regulatory areas of the brain. C Show more
Introduction: Pathogenic heterozygous melanocortin-4 receptor (MC4R) variants are the most common cause of monogenic obesity, affecting central satiety and appetite regulatory areas of the brain. Case Presentations: We report a pedigree with a pathogenic MC4R variant (c.380C>T, p.Ser127Leu). In the proband with obesity (BMI 35 kg/m2) and severe insulin resistance, use of combination of semaglutide and naltrexone-bupropion was successful in reducing insulin requirements and weight. His adult monozygotic twin daughters both had childhood-onset obesity; however, weight trajectories differed. Twin 1 had a peak BMI of 29.1 kg/m2, which decreased to 19.7 kg/m2 with intensive exercise and diet control without weight-lowering medication. Twin 2 had a sedentary lifestyle and epilepsy and had a peak BMI of 30.1 kg/m2; she responded well to naltrexone-bupropion and BMI decreased to 26 kg/m2. Conclusion: The manifestation of obesity, even in cases of monogenic obesity, can vary significantly due to the influence of environmental and lifestyle factors.
Obesity is associated with adverse effects on health and quality of life. Improved understanding of its underlying pathophysiology is essential for developing counteractive measures. To search for seq Show more
Obesity is associated with adverse effects on health and quality of life. Improved understanding of its underlying pathophysiology is essential for developing counteractive measures. To search for sequence variants with large effects on BMI, we perform a multi-ancestry meta-analysis of 13 genome-wide association studies on BMI, including data derived from 1,534,555 individuals of European ancestry, 339,657 of Asian ancestry, and 130,968 of African ancestry. We identify an intergenic 262,760 base pair deletion at the MC4R locus that associates with 4.11 kg/m Show less
Obesity stands out as the most common multifactorial nutritional problem affecting domestic cats. According to studies, the prevalence of overweight or obese cats varies between 11.5% and 63%. Various Show more
Obesity stands out as the most common multifactorial nutritional problem affecting domestic cats. According to studies, the prevalence of overweight or obese cats varies between 11.5% and 63%. Various factors such as breed, age, gender, reproductive status, owner-pet relationship, diet type, and environmental factors have been identified as potential risk factors for the development of obesity in cats. Among the genes involved in regulating energy balance, one of the prominent genes is melanocortin-4 receptor gene (MC4R). A specific missense variant in the feline MC4R gene (c.92 C > T) has been associated with overweight in diabetic domestic shorthaired cats. In this study, it was aimed to determine the polymorphisms in MC4R gene in random bred cats and cats belonging to a registered breed in Turkey and to investigate their relationship with obesity. Blood samples from 30 obese and 20 non-obese cats were collected into sterile vacuum EDTA tubes. Exon 1 of the MC4R was amplified and sequenced. As a result of DNA sequence analysis, we identified a total of six SNPs in the feline MC4R gene, four of which were found for the first time in this study. As a result of comparing allele frequencies in obese and non-obese cats, a significant relationship was found between SNP rs783632116 and obesity. The results of regression analyses evaluating the effects of SNP genotypes, sex and infertility status on feline Body Mass Index (fBMI) indicated that non-synonymous SNPs rs783632116, ss11356259660 and ss11356259661 were significantly associated with fBMI. Show less
Leptin, a key adipokine regulating energy homeostasis, has been extensively studied for its potential in the management of obesity. However, its therapeutic efficacy is often limited due to leptin res Show more
Leptin, a key adipokine regulating energy homeostasis, has been extensively studied for its potential in the management of obesity. However, its therapeutic efficacy is often limited due to leptin resistance. This review synthesizes animal and clinical evidence on leptin's role in obesity, focusing on models such as genetically deficient mice (e.g., ob/ob, db/db), diet-induced obesity mice, and clinical conditions such as congenital leptin deficiency (CLD), leptin receptor deficiency (LRD), lipodystrophy, and common obesity. The mechanisms underlying leptin resistance are summarized, including hyperleptinemia, impaired JAK2-STAT3 signaling, reduced blood-brain barrier permeability, defective autophagy, endoplasmic reticulum stress, inflammation, decreased leptin receptor expression, leptin signaling pathway dysfunction, increased mTOR activity, and peripheral leptin resistance. Due to these leptin receptor and/or post-receptor signaling pathway defects, leptin or its analogs usually fail to produce the expected weight-loss effect in individuals with overweight or obesity, although they remain highly effective in individuals with CLD and lipodystrophy, as well as in ob/ob mice. Alternative strategies, such as melanocortin-4 receptor (MC4R) agonists (e.g., setmelanotide) for LRD treatment, are very promising. Future directions include enhancing leptin sensitization, combining leptin with other drugs, and exploring partial leptin reduction to mitigate compensatory responses during weight loss. The review emphasizes the complexity of leptin resistance and the necessity of targeted approaches in obesity therapy. Show less
Disruptive eating behaviors can negatively impact psychological well-being and increase the risk of metabolic diseases such as obesity, type 2 diabetes, and cardiovascular disease. While behavioral st Show more
Disruptive eating behaviors can negatively impact psychological well-being and increase the risk of metabolic diseases such as obesity, type 2 diabetes, and cardiovascular disease. While behavioral strategies remain central to dietary interventions, emerging research highlights genetic factors, particularly single nucleotide polymorphisms (SNPs), as contributors to individual differences in eating behaviors. This scoping review maps existing research on genetic modifiers of adult eating behaviors, identifying key variants and genetic predispositions. An extensive systematic search was conducted across 12 electronic databases, including PubMed, MEDLINE, and EMBASE, alongside relevant grey literature. Sixty-five studies published from 2014 to April 2024 met inclusion criteria. Data were synthesized using Covidence and NVivo for thematic mapping. Studies were eligible if they utilized genotyping to examine genetic markers, variations, or SNPs in relation to adult eating behaviors using validated questionnaires and/or dietary interventions. Six key themes emerged: taste perception; appetite and satiety; emotional eating; disinhibition; food timing and eating habits; and snacking, craving and binge eating. Frequently studied genes included CD36, MC4R, FTO, TAS1R, TAS2R, SLC4A5, SLC6A2, SLC6A4, DRD2, CLOCK, ADIPOQ and CA6, with some studies incorporating genetic risk scores. Across reviewed studies, there was a female predominance (female-to-male ratio of 1.6:1), while older adults were underrepresented (mean age: 35.2 ± 8.4 years). Cross-sectional study designs (58 %), highlighted a methodological gap, underscoring the need for longitudinal research to explore causality. This review provides valuable insights into the genetic underpinnings of eating behaviors and emphasizes the need for future research in more diverse populations to support precision nutrition strategies. Show less
Metabolic diseases, like type 2 diabetes mellitus and obesity, show a growing public health concern in Sri Lanka. Genetic predisposition and diet contribute to metabolic disease risk, but there are li Show more
Metabolic diseases, like type 2 diabetes mellitus and obesity, show a growing public health concern in Sri Lanka. Genetic predisposition and diet contribute to metabolic disease risk, but there are limited investigations into the impact of gene-diet interactions on metabolic disease risk in the Sri Lankan population. In this study, we examined whether a metabolic genetic risk score (GRS), constructed from 10 single nucleotide polymorphisms (SNPs), interacts with dietary factors to influence metabolic health indicators in Sri Lankan adults. This cross-sectional study included 105 generally healthy adults aged 25-50 years from the GOOD (Genetics of Obesity and Diabetes) study. Anthropometric, biochemical, and dietary data using food frequency questionnaires were collected using validated methods. Genotyping was performed using the KASP A statistically significant interaction was identified between the 10-SNP metabolic GRS and polyunsaturated fatty acid (PUFA) intake on waist circumference (P This study provides novel insights to understand gene-diet interactions affecting metabolic traits in Sri Lankans. The findings suggest that higher PUFA intake may mitigate genetic susceptibility to central obesity, highlighting the importance of personalized dietary recommendations for metabolic disease prevention. Further studies in larger cohorts are warranted to confirm this finding. Show less
Biallelic variants in the pro-opiomelanocortin gene (POMC) can cause hypocortisolism, hypopigmentation, and early-onset obesity. Following the identification of 2 patients of combined pituitary hormon Show more
Biallelic variants in the pro-opiomelanocortin gene (POMC) can cause hypocortisolism, hypopigmentation, and early-onset obesity. Following the identification of 2 patients of combined pituitary hormone deficiency (CPHD), we investigated the prevalence of this association among carriers of rare pathogenic or likely pathogenic (P/LP) POMC variants. This study is a case report and systematic literature review. Genetic analysis was conducted in a family with 2 cousins with childhood-onset obesity and CPHD. We assessed CPHD in carriers for biallelic pathogenic POMC variants using data from the literature and Human Gene Mutation Database. Clinical and biological data were collected, including pituitary axis involvement, obesity onset age, and pituitary imaging results. The 2 cousins, compound heterozygous for POMC variants, developed CPHD following initial hypocortisolism, with subsequent hypothyroidism, growth hormone deficiency, and hypogonadism. Among 41 patients with biallelic POMC variants identified in the literature, 20 had rare homozygous/compound heterozygous P/LP POMC variants and detailed endocrine evaluations. Of these, 40% presented with CPHD, always associated with early-onset severe obesity and hypocortisolism. Growth hormone deficiency was the most frequent (75%), followed by thyrotropic and gonadotropic deficiencies (62.5%). No anomalies were revealed in pituitary imaging. Two patients recovered the gonadotropic axis after treatment with the MC4R agonist. These findings underscore the potential for CPHD to occur in carriers of biallelic pathogenic POMC variants. Sequencing the full POMC, including coding and regulatory regions, is crucial in CPHD cases, alongside evaluating all pituitary axes in neonatal hypocortisolism. Beyond weight regulation, setmelanotide may modulate hypothalamic-pituitary function, with implications for fertility. Show less
Osteoarthritis (OA) is a common progressive joint disorder marked by synovial inflammation, cartilage degeneration, the formation of osteophytes, though its underlying molecular mechanisms remain uncl Show more
Osteoarthritis (OA) is a common progressive joint disorder marked by synovial inflammation, cartilage degeneration, the formation of osteophytes, though its underlying molecular mechanisms remain unclear. This study integrated bioinformatics and experimental validation to identify key genes in OA synovium and their association with immune infiltration. Analysis of the GSE82107 dataset (10 OA, 7 controls) revealed 909 differentially expressed genes (525 upregulated, 384 downregulated). WGCNA identified the "midnightblue" module, and its intersection with DEGs yielded 122 genes enriched in cytokine-cytokine receptor interaction, JAK-STAT signaling, and autophagy pathways. Protein-protein interaction analysis highlighted FLT3LG, MC4R, CXCL10, CARTPT, and LHX2 as core genes (AUC 0.743-0.871). Immune infiltration analysis showed elevated M0 macrophages in OA, with CXCL10 showing a strong positive correlation with M1 macrophage infiltration (r = 0.74), and MC4R correlating with the presence of follicular helper T cells (r = 0.85). In vitro, OA-derived fibroblast-like synoviocytes exhibited CXCL10 upregulation, MC4R downregulation, and increased IL-6, IL-8, and TNF-α secretion, which were markedly reduced by CXCL10 knockdown or MC4R overexpression. Synovial tissue assays confirmed these expression patterns. CXCL10 and MC4R may represent promising diagnostic markers and therapeutic targets, offering new insights into OA immunopathogenesis and precision intervention. Show less
Maternal consumption of monosaccharides during pregnancy and lactation can program long-term metabolic and neurobehavioral outcomes in offspring. The melanocortin-4 receptor (MC4R) is a key regulator Show more
Maternal consumption of monosaccharides during pregnancy and lactation can program long-term metabolic and neurobehavioral outcomes in offspring. The melanocortin-4 receptor (MC4R) is a key regulator of metabolism and behavior. However, the impact of maternal monosaccharide diets on MC4R signaling within mesocorticolimbic regions remains unclear. In this study, we investigated the effects of maternal glucose (GLU) and fructose (FRU) diets on metabolic, molecular, and neurochemical outcomes in offspring. Adolescent and young adult male and female Wistar rat offspring, following maternal GLU and FRU exposure during pregnancy and lactation, underwent sucrose preference testing, intraperitoneal glucose tolerance tests, and serum lipid profiling. In addition, the gene expression of The maternal GLU diet reduced total calorie intake during lactation, while the FRU diet increased the dams’ caloric intake from sugar during both pregnancy and lactation. In the offspring, a maternal FRU diet increased sucrose consumption in young adult males and dysregulated glucose homeostasis in both adolescent and young adult males. Maternal monosaccharide diets also influenced serum lipid profiles and increased the body weights of their offspring. At the molecular level, region-, sex-, and age-specific changes in gene expression were observed, particularly the upregulation of These findings suggest that maternal monosaccharide diets induce persistent alterations in the metabolic profiles of offspring and MC4R signaling, potentially contributing to the development of programmed metabolic and behavioral outcomes. Not applicable. The online version contains supplementary material available at 10.1007/s43440-025-00785-8. Show less
Adamantinomatous craniopharyngioma (ACP) is a histologically benign but clinically aggressive tumor arising from Rathke's pouch remnants, which is molecularly distinct from the other subtype, papillar Show more
Adamantinomatous craniopharyngioma (ACP) is a histologically benign but clinically aggressive tumor arising from Rathke's pouch remnants, which is molecularly distinct from the other subtype, papillary craniopharyngioma (PCP). Despite advancements in surgery and radiotherapy, treatment outcomes remain unsatisfactory due to the tumor's invasiveness and resistance to conventional therapies. This review systematically examines the molecular pathogenesis of ACP and evaluates current and emerging therapeutic strategies to improve clinical management. ACP is driven by CTNNB1 mutations and dysregulated Wnt/β-catenin signaling, alongside inflammatory and senescence-associated pathways. Current pharmacological approaches, including interferon-α, IL-6 inhibitors (e.g., tocilizumab), and intracystic agents (e.g., bleomycin), exhibit limited efficacy. Promising emerging therapies target the angiogenesis (e.g., bevacizumab) and MAPK/ERK pathway, which is activated by somatic BRAF V600E mutations in PCP, has been successfully targeted with BRAF/MEK inhibitors, demonstrating significant efficacy in the majority of treated PCP patients. whereas immune checkpoint inhibitors and SHH pathway modulators face significant challenges. Additionally, ACP-related endocrine dysfunction and hypothalamic obesity require tailored interventions, such as GLP-1 receptor agonists and MC4R-targeted therapies. Precision medicine, informed by molecular subtyping and multi-omics data, holds transformative potential for ACP treatment. Future strategies should focus on combinatorial therapies to address tumor heterogeneity, microenvironment modulation, and senolytic approaches. Collaborative multidisciplinary efforts are crucial to translating these insights into clinical practice, ultimately enhancing patient outcomes and quality of life. Show less
Hypothalamic pro-opiomelanocortin (POMC) neurons are classically viewed as mediators of satiety, acting in response to metabolic and hormonal cues and in opposition to Agouti-related protein (AgRP) ne Show more
Hypothalamic pro-opiomelanocortin (POMC) neurons are classically viewed as mediators of satiety, acting in response to metabolic and hormonal cues and in opposition to Agouti-related protein (AgRP) neurons to maintain energy balance. This model, centered on the appetite-suppressant effects of the POMC-derived neuropeptide α-melanocyte-stimulating hormone (α-MSH) through its activation of melanocortin-4 receptors (MC4R), has shaped our understanding of feeding and body weight regulation for decades. However, recent discoveries have challenged and expanded this traditional view, revealing that POMC neurons are not a uniform population dedicated solely to satiety control. Single-cell transcriptomic analyses have revealed striking molecular heterogeneity, reflected in distinct anatomical distributions, receptor expression profiles, electrophysiological properties, and projection patterns - all supporting the idea of functional specialization within this neuronal population. In this review, we propose a conceptual framework that integrates POMC neuronal heterogeneity with the regulation of appetite, metabolic physiology, and behavior beyond feeding. We highlight emerging evidence showing that discrete POMC neuronal subpopulations respond to specific combinations of interoceptive and environmental cues to orchestrate diverse adaptive responses. This perspective underscores the developmental plasticity and functional versatility of POMC neurons, offering new insights into the mechanisms of obesity and potentially paving the way for novel targeted therapeutic strategies. Show less
The dopaminergic system is crucial for affect regulation. Melanocortin 4 receptors (MC4R) in the ventral striatum have been shown to be necessary for establishing aversive states. Here, we functionall Show more
The dopaminergic system is crucial for affect regulation. Melanocortin 4 receptors (MC4R) in the ventral striatum have been shown to be necessary for establishing aversive states. Here, we functionally characterize MC4R-expressing striatal neurons in mice. MC4Rs were enriched in atypical dopamine receptor 1 (D1) neurons in the lateral stripe of the striatum (LSS), an understudied area in the ventrolateral striatum. Fiber photometry recordings showed that MC4R neuron activity and local dopamine release in the LSS increased in response to both rewarding and aversive stimuli. Moreover, MC4R neuronal activity and glutamate release in the LSS correlated with body movement. Optogenetic activation of MC4R-LSS neurons was rewarding in a real-time place preference test and a self-stimulation paradigm, increased locomotor activity, and induced striatal dopamine release. Collectively, our findings suggest that MC4R-LSS neurons are activated by stimuli of both rewarding and aversive character and that they induce positive affect, dopamine release and locomotion. Show less
The central melanocortin system, composed of peptides derived from pro-opiomelanocortin (POMC) such as the melanocyte-stimulating hormones (α-, β-, γ-MSH) and melanocortin 4 receptors (MC4R), along wi Show more
The central melanocortin system, composed of peptides derived from pro-opiomelanocortin (POMC) such as the melanocyte-stimulating hormones (α-, β-, γ-MSH) and melanocortin 4 receptors (MC4R), along with the agouti-related protein (AgRP), plays a pivotal role in controlling energy balance. To elucidate the dynamic role of α-MSH release in regulating appetite, specific, sensitive, and spatiotemporally resolved genetic sensors are required. The melanocortin 1 receptor (MC1R) scaffold was leveraged for its robust plasma membrane expression, high affinity for melanocortins and low affinity for AgRP to design a α-MSH selective sensor for in vivo use. This was achieved by integrating circularly permuted green fluorescent protein (cpGFP) into the receptor, which we named Fluorescence Amplified Receptor sensor for Melanocortin (FLARE The FLARE FLARE Show less
The aim of this study was to analyse the allelic distribution of selected genes in the Czech and Vietnamese populations. We analysed samples from 94 Vietnamese volunteers and 2,859 Czech population-ba Show more
The aim of this study was to analyse the allelic distribution of selected genes in the Czech and Vietnamese populations. We analysed samples from 94 Vietnamese volunteers and 2,859 Czech population-based subjects (2,559 from the Czechs post-MONICA and 300 volunteers from the South region of the Czech Republic). There were significant differences between the two populations for most, but not all, of the SNPs analysed. In particular, the prevalence of risk alleles in the analysed polymorphisms tended to be lower in the Vietnamese community compared to the Czech population, especially within the FTO (rs17817449; associated with obesity risk, P < 0.0001), TCF7L2 (rs7903146; linked to type 2 dia-betes, P < 0.0001) and ADH1B (rs1229984; related to alcohol consumption, P < 0.0001) genes. The genotype within the MCM6/LCT cluster (rs4988235) associated with lactase persistence was not present in the Vietnamese population. Slight genotype differences were detected for one HFE polymorphism (rs1799945 with P = 0.005; but not for rs1800562). Only the genotype frequencies within the MC4R and APOE genes were almost identical in both populations. We conclude that the Vietnamese population may have a lower genetic predisposition to the non-communicable diseases such as obesity or diabetes mellitus. Show less
Adipocytokines, including leptin, adiponectin, and resistin, are key mediators linking adiposity, insulin resistance, and inflammation. We present the first genome-wide association study (GWAS; NÂ =Â 52 Show more
Adipocytokines, including leptin, adiponectin, and resistin, are key mediators linking adiposity, insulin resistance, and inflammation. We present the first genome-wide association study (GWAS; NÂ =Â 5258) and exome-wide association study (ExWAS; NÂ =Â 4578) on leptin, adiponectin, and resistin in South Asian population. We identified novel associations in genes ZNF467, and LEPREL2 for leptin; ZNF467, LEPREL2, CRLF3, ZNF732, SOX30, XIRP1, ATP8B3, SPATA2L, TMCO4, TLN2, ABCA12, and SHB for adiponectin; and D2HGDH for resistin. Additionally, we confirmed known associations of FTO, MC4R, and HOXB3 with leptin and ADIPOQ with adiponectin. Notably, ADIPOQ variants were consistently significant across GWAS, ExWAS, and gene-based analyses, reinforcing their central role in regulating adiponectin levels. Most of these novel associations identified were population-specific, highlighting the importance of studying diverse populations to uncover unique genetic signals. After adjusting for BMI, the associations with adiponectin and resistin remained significant, whereas most associations for leptin weakened in both effect size and significance. Functional annotation revealed that the identified variants were enriched for expression in adipose tissue, the brain (cerebellar hemisphere and cerebral cortex), and the pituitary gland. These variants act as eQTLs and splice-QTLs in adipose, brain, and pancreas, suggesting cross-tissue regulatory mechanisms. ExWAS further implicated rare variant burden in genes such as LONP1, ZNF335, and TTC16 for adiponectin and resistin. These findings enhance our understanding of adipocytokine biology, emphasises the need for population-specific genetic research, and lays foundation for future functional studies. Show less
Depression, a prevalent psychiatric disorder, exerts severe and debilitating impacts on an individual's mental and physical well-being, and it is considered a chronic mental illness. Chronic stress pl Show more
Depression, a prevalent psychiatric disorder, exerts severe and debilitating impacts on an individual's mental and physical well-being, and it is considered a chronic mental illness. Chronic stress plays an important role in the pathophysiology of depression. Lactobacillus plantarum and Streptococcus thermophilus are psychobiotic bacteria and synthesize some neurotransmitters that play a role in the pathogenesis of depression. In this study, we aimed to investigate the therapeutic effects of Bactolac (Lactobacillus plantarum NBIMCC 8767  + Streptococcus thermophilus NBIMCC 8258) on chronic stress-induced depression in rats. Behavioral tests, including the sucrose preference test, elevated plus maze test, forced swim test, and three-chamber sociability test, were employed to assess depressive and anxiety-like behaviors. The expression level of the 5-HT1A, DRD1, ADRA-2A, GABA-A α1, CNR1, NR3C2, NOD1, NLRP3 and MC4R; BDNF levels, glial activity and intestinal permeability were determined in chronic stress-induced depression in rats. In conclusions, chronic stress decreased the expression levels of 5-HT1A, DRD1, ADRA-2A, GABA-A α1, CNR1, NR3C2, NOD1 and BDNF level; increased the expression levels of NLRP3 and MC4R, caused neurodegeneration and glial activity, ultimately led to depressive effects. Bactolac was effective in reducing depressive-like behaviors according to the results of behavioral tests. Bactolac treatment provided high neuronal survival rate increasing BDNF level, prevented the excessive release of pro-inflammatory cytokines by reducing the expression levels of NLRP3 and MC4R, therefore, prevented the excessive activation of the hypothalamus-pituitary-adrenal (HPA) axis and accordingly, reduced neurodegeneration and glial cell activation in depressed rats. We can suggest that Bactolac supplementation may be beneficial in coping with stress, alleviate the effects of chronic stress and help to protect mental health. Show less
Philip L Beales, Metin Cetiner, Andrea M Haqq+5 more · 2025 · Obesity reviews : an official journal of the International Association for the Study of Obesity · Blackwell Publishing · added 2026-04-24
Bardet-Biedl syndrome (BBS) is a rare, genetically heterogeneous, and highly pleiotropic autosomal recessive ciliopathy. Patients typically present with early loss of vision, hyperphagia, severe obesi Show more
Bardet-Biedl syndrome (BBS) is a rare, genetically heterogeneous, and highly pleiotropic autosomal recessive ciliopathy. Patients typically present with early loss of vision, hyperphagia, severe obesity, learning difficulties, and renal dysfunction. In patients with BBS, dysfunction of the immotile primary cilia in the hypothalamic melanocortin-4 receptor (MC4R) pathway responsible for controlling energy balance, hunger, and satiety results in severe hyperphagia manifesting in food-seeking behaviors that drive the development of obesity early in childhood. These behaviors have negative impacts on many areas of the lives of patients with BBS and their families/caregivers, including sleep, mood, school/work, and social/family relationships. Additionally, many patients feel stigmatized due to their hyperphagia-associated food-seeking behaviors and the resulting obesity, which exacerbates the impacts of hyperphagia on quality of life. Early identification and management of hyperphagia in patients with BBS is key: mitigating food-seeking and weight gain can improve quality of life and reduce the risk of metabolic and cardiovascular diseases that is increased in patients with BBS. Until recently, the only treatment strategies available were lifestyle and diet modifications. However, targeted treatment with the novel MC4R agonist setmelanotide now offers an effective management option to reduce hyperphagia and weight in patients with BBS, improving overall health and quality of life. Show less
Epilepsy, affecting millions globally, often leads to significant cognitive and psychiatric comorbidities, particularly in children. Anxiety and depression are particularly prevalent, with roughly a q Show more
Epilepsy, affecting millions globally, often leads to significant cognitive and psychiatric comorbidities, particularly in children. Anxiety and depression are particularly prevalent, with roughly a quarter of pediatric epilepsy patients having a comorbid diagnosis. Current treatments inadequately address these issues. Adrenocorticotropic hormone (ACTH), a melanocortin peptide, has shown promise in mitigating deficits after early-life seizures (ELS), potentially through mechanisms beyond its canonical action on the melanocortin 2 receptor. This study explores the hypothesis that recurrent ELS is associated with long-term anxiety and that treatment with ACTH can prevent this anxiety through a mechanism that involves the melanocortin 4 receptor (MC4R) in the brain. Our findings reveal that ACTH ameliorates anxiety-like behavior associated with ELS, without altering seizure parameters, in wild-type but not in male and female MC4R knock-out mice. Our findings also show that knocking-in MC4R in either neurons or astrocytes was able to rescue the anxiety-like behavior after ACTH treatment. Furthermore, our results show that ACTH normalizes important astrocytic proteins like glial fibrillary acidic protein and aquaporin-4 after ELS. This suggests that ACTH's beneficial effects on anxiety are mediated through MC4R activation in both neuronal and astrocytic populations. This study underscores the therapeutic potential of targeting MC4R as a treatment, highlighting its role in mitigating anxiety-like behaviors associated with ELS. Show less
We aimed to investigate whether genetic variants in the leptin-melanocortin system involved in anorexigenic signaling influence personality dimensions and psychopathological symptoms in eating disorde Show more
We aimed to investigate whether genetic variants in the leptin-melanocortin system involved in anorexigenic signaling influence personality dimensions and psychopathological symptoms in eating disorders (ED) patients. The population consisted of 309 ED patients [221 with anorexia nervosa (AN) and 88 with bulimia nervosa (BN)] and 396 healthy controls. Patients underwent psychometric assessment using the Eating Disorders Inventory Test-2 (EDI-2) and the Symptom Checklist 90 Revised (SCL-90R) questionnaires. Fourteen tag-SNPs in the LEP, POMC, and MC4R genes, were determined. Drive for thinness (DT) was significantly affected by genetic variability. After correction for multiple testing, regression models showed that AN patients carrying the LEP rs11761556 CC variant genotype scored higher in this scale than AA/CA carriers did [mean difference = 4.43 (2.18-6.68), p < 0.001], although the significance was restrained to the restrictive subtype [4.92 (2.00-7.83), p = 0.001]. BN patients with the LEP rs10954173 AA genotype displayed lower scores [-8.7 (-12.31--3.91); p < 0.001]. Finally, gene-gene interaction analyses revealed two SNP pairs associated with body-mass index in AN patients (LEPrs3828942-POMCrs1009388, p < 0.001 and LEP rs11763517-POMCrs1009388, p = 0.002). Regarding DT scores, the POMCrs6545975-LEP11763517 SNP pair showed the strongest effect (p < 0.001) in AN. Genetic variants in the leptin-melanocortin system, may interact to influence personality dimensions in ED patients, which highlights the importance of considering genetic factors in the pathophysiology of these disorders. Show less
Weight loss medications are emerging candidates for pharmacotherapy of sleep-disordered breathing (SDB). A melanocortin 4 receptor (MC4R) agonist, setmelanotide (Set), is used to treat obesity caused Show more
Weight loss medications are emerging candidates for pharmacotherapy of sleep-disordered breathing (SDB). A melanocortin 4 receptor (MC4R) agonist, setmelanotide (Set), is used to treat obesity caused by abnormal melanocortin and leptin signaling. We hypothesized that Set can treat SDB in mice with diet-induced obesity. We performed a proof-of-concept randomized crossover trial of a single dose of Set versus vehicle and a 2-week daily Set versus vehicle trial, examined colocalization of Mc4r mRNAs with the markers of CO2-sensing neurons Phox2b and neuromedin B in the brainstem, and expressed Cre-dependent designer receptors exclusively activated by designer drugs (DREADDs) or caspase in obese Mc4r-Cre mice. Set increased minute ventilation across sleep/wake states, enhanced the hypercapnic ventilatory response (HCVR), and abolished apneas during sleep. Phox2b+ neurons in the nucleus of the solitary tract (NTS) and the parafacial region expressed Mc4r. Chemogenetic stimulation of the MC4R+ neurons in the parafacial region, but not in the NTS, augmented HCVR without any changes in metabolism. Caspase elimination of the parafacial MC4R+ neurons abolished effects of Set on HCVR. Parafacial MC4R+ neurons projected to the respiratory premotor neurons retrogradely labeled from C3-C4. In conclusion, MC4R agonists enhance the HCVR and treat SDB by acting on the parafacial MC4R+ neurons. Show less
Some individuals are more susceptible to developing or suffering from pain states than others. However, the brain mechanisms underlying the susceptibility to pain responses are unknown. In this study, Show more
Some individuals are more susceptible to developing or suffering from pain states than others. However, the brain mechanisms underlying the susceptibility to pain responses are unknown. In this study, we defined pain susceptibility by recapitulating inter-individual differences in pain responses in mice exposed to a paradigm of socially transferred allodynia (STA), and with a combination of chemogenetic, molecular, pharmacological and electrophysiological approaches, we identified GABA-ergic neurons in the dorsal raphe nucleus (DRN) as a cellular target for the development and maintenance of STA susceptibility. We showed that DRN GABA-ergic neurons were selectively activated in STA-susceptible mice when compared with the unsusceptible (resilient) or control mice. Chemogenetic activation of DRN GABA-ergic neurons promoted STA susceptibility; whereas inhibiting these neurons prevented the development of STA susceptibility and reversed established STA. In in vitro slice electrophysiological analysis, we demonstrated that melanocortin 4 receptor (MC4R) enriched in DRN GABA-ergic neurons was a molecular target for regulating pain susceptibility, possibly by affecting DRN GABA-ergic neuronal activity. These results establish the DRN GABA-ergic neurons as an essential target for controlling pain susceptibility, thus providing important information for developing conceptually innovative and more accurate analgesic strategies. Show less
Childhood obesity (OB) is influenced by complex gene-environmental interaction. While genetics of adult OB have been extensively studied, polygenic childhood OB in non-European populations is still un Show more
Childhood obesity (OB) is influenced by complex gene-environmental interaction. While genetics of adult OB have been extensively studied, polygenic childhood OB in non-European populations is still underexplored. Furthermore, in a developing nation such as India, how the environmental component strongly modulated by the socioeconomic status (SES) shapes the genetic susceptibility is crucial to understand. A two-staged genome-wide association study (GWAS; N = 5673) and an independent exome-wide association study (ExWAS; N = 4963) were performed using a generalized linear model assuming additive effect to identify the common and rare genetic variants respectively associated with childhood OB. Rare-variant burden testing was also performed. We used the gene expression profiles and regulatory data from public databases to explain the novel associations. The implications of SES as a potential modifier of genetic susceptibility were evaluated. GWAS identified novel associations in TCF7L2, IMMP2L, IPMK, CDC5L, SNTG1, and MX1, whereas ExWAS uncovered CNTN4, COQ4, TNFRSF10D, FLG-AS1, and BMP3. Both GWAS and ExWAS validated known associations in FTO and MC4R. Furthermore, rare-variant testing highlighted the role of 101 genes. We also observed that SES can modulate the inherent susceptibility to OB. Our study identified genetic variants associated with childhood OB and highlighted the gene-environmental interaction in childhood OB. Show less